bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study of the Kultschitzky (Argentaffin) Cell with the Electron-microscope, after Fixation by Osmium Tetroxide
Authors: Christie A. C.
Published: April 2021

1. The Kultschitzky cells of the alimentary canal of man and the guinea-pig were studied with the light-microscope, buffered osmium tetroxide being used as fixative.

2. The Kultschitzky cells of the guinea-pig were shown by the electron-microscope to contain spheroidal granules having a maximum diameter of 0·3 μ. These granules are considerably darkened by fixation for only 4 hours in 1% osmium tetroxide solution.

3. The opinion that the granules of the Kultschitzky cell are only an artifact of formaldehyde fixation is denied.
Activity of the Brain/Gorpora Cardiaca System during Pupal Diapause ‘Break’ in Mimas tiliae (Lepidoptera)
Authors: Highnam K. C.
Published: April 2021

Pupal diapause in Mimas tiliae can be terminated by keeping the pupa for at least 4 weeks at 3° C. The adult emerges about 15 days after transfer to 25° C.

Histological examination shows that the neurosecretory cells in the brain are inactive in the diapausing pupa, but they elaborate intracellular material during the first 3 weeks at 3° C. The material is passed to the corpora cardiaca. The neurosecretory cells are again inactive by the end of the low-temperature period.

The brain/cardiaca system shows little sign of secretory activity during the subsequent period at 25° C. The corpora cardiaca undergo phagocytosis and reorganization during this time. This suggests that conditions for further development are established by the end of the low-temperature period. This hypothesis is supported by the fact that development of the non-endocrine organs begins immediately the pupa is transferred to 25° C after 4 weeks at 3° C.

Extirpation and implantation experiments involving the brain, with and without its associated corpora cardiaca, support the histological results, indicating that the brain is necessary for diapause development at 3° C and that the corpora cardiaca are involved in the release of the brain factor.
Dimethyl Hydantoin Formaldehyde: A new Water-soluble Resin for Use as a Mounting Medium
Authors: Steedman H. F.
Published: April 2021

Dimethyl hydantoin formaldehyde resin dissolved in water or in 70 ml ethyl alcohol+30 ml water is put forward as a solution suitable for the mounting of insects, small Crustacea, &c. Its chief advantage over other water-soluble resins is its high solubility in water, its excellent adhesion to glass, its low viscosity even in high percentage solutions, and its hardness on drying.
The Uptake of Intravital Dyes by the Testis
Authors: Grant J. H.
Published: April 2021

The vital staining reactions of the normal and ischaemic testis were investigated in 20 rats by the use of varying amounts of trypan blue and Unna’s polychrome methylene blue. The experiments showed that it was possible to distinguish both true and reticulo-endothelial interstitial cell types. The implications of this subdivision are discussed and their importance in relation to neoplasms of the Leydig cells stressed. The distribution of mast cells in the testis is described.
Studies on the growth of tissues In vitro
Authors: Willmer E. N.
Published: April 2021

A method is described by which cells in the zone of outgrowth of cultures in flasks can be photographed at definite intervals over long periods of time. The rate of growth of chick heart tissue when growing in the presence and absence of embryo extract has been investigated. A numerical value, the growth index, has been calculated which expresses the mitotic activity of the culture during the periods of observation. In plasma alone the growth index is approximately 3 after 20 hours of growth and falls to zero at the 70th hour if the fluid medium above the plasma (in this case Tyrode) is not renewed. In plasma and embryo extract-(fluid medium embryo extract unchanged) the growth index is approximately 9 after 30 hours of growth, and falls to zero at about the 140th hour. If the fluid medium is frequently renewed with fresh embryo extract the growth index quickly falls to 3, and in the one case followed for more than 4 days it remained fluctuating about that level for the next 6 days, in fact for as long as it was practically possible to prolong the experiment. It is suggested that the method has many applications in connection with problems associated with the growth rates of tissues and organisms.
Intracellular Recordings From Interneurones and Motoneurones During Bilateral Kicks in the Locust: Implications for Mechanisms Controlling the Jump
Authors: Gynther I. C. , Pearson K. G.
Published: April 2021

Intracellular recordings were made from the neuropile processes of thoracic neurones of Locusta migratoria during bilateral kicks of the hindlegs. Electromyographic (EMG) recordings showed that the pattern of flexor and extensor tibiae muscle activity during kicks in this extensively dissected preparation was similar to that seen during a jump. Intracellular recordings from hindleg flexor and extensor motoneurones and from 13 identified interneurones revealed additional features of the motor programme for jumping and kicking and of the mechanism which triggers these events.

There was a discrete burst of activity in the fast extensor tibiae (FETi) moto-neurone at the end of the co-contraction phase, generated by a system that appeared to be separate from that triggering the kick. The excitatory connection from FETi to flexors was not responsible for initiating flexor activity and was of little functional importance in maintaining this activity during the co-contraction phase. The initial flexor excitation came from another, unidentified, central source.

A pair of identified interneurones, the M-neurones, discharged with a high frequency burst just prior to the kick. Since these neurones inhibit hindleg flexor tibiae motoneurones, this observation provides further support for their proposed role as the neurones responsible for triggering kicks and jumps. Our data do not support the proposal that the activation of the M-neurones depends on them receiving progressively increasing proprioceptive input during the co-contraction phase. Throughout co-contraction, the M-neurones were hyperpolarized. Their activation was rapid and strong enough to cause them to discharge at rates as high as 400 spikes s−1. We suggest that the pulse-like activation of the M-neurones is produced centrally by a higher order system of interneurones.

Another pair of previously identified interneurones, the C-neurones, were not necessary for the generation of the co-contraction phase of the motor programme. Their pattern of activity and their known connections indicated that they provide additional excitation to the flexors and extensors towards the end of co-contraction.

Many other interneurones discharged either during co-contraction or when a kick was triggered. We conclude that the system generating the motor programme for a kick (jump) is more complex than proposed in previous studies.
Sprouting by Undamaged Adult Molluscan Neurones: Putative Role for Changes in Haemolymph Osmoregulation
Authors: Maetzold D. J. , Bulloch A. G. M.
Published: April 2021

Sprouting of undamaged, adult neurones has been observed in a number of situations. For instance, in the peripheral nervous system of vertebrates, intact motoneurones exhibit terminal sprouting in response to axotomy of contralateral motoneurones (Rotshenker, 1979; Rotshenker & Tal, 1985) and in the central nervous system, neurones have been observed to sprout and occupy synapses vacated by lesioned fibres (Cotman, Nieto-Sampedro & Harris, 1981; Tsukahara, 1981). Furthermore, evidence also exists for dendritic sprouting and regression in the mature, human brain (Buell & Coleman, 1981). The plastic properties of the neurones of the freshwater pulmonate Helisoma have been examined in a number of regeneration and sprouting studies (e.g. Murphy & Kater, 1980; Bulloch & Kater, 1982; reviewed by Bulloch, 1985a). Recently, it was demonstrated that sprouting and retraction of a central neurite occurred from an undamaged adult neurone of Helisoma in response to stress (Bulloch, 1984). Specifically, sprouting occurred in a pair of buccal neurones, L5 and R5, and aestivation and body wall incision were the most effective treatments examined. Body wall incision results in haemolymph loss, and aestivation results in a loss of water and thus an increase in haemolymph osmolarity (Machin, 1975). These observations raise the possibility that the sprouting of neurones L5 and R5 may occur in response to changes in haemolymph osmoregulation. The current study directly tested the hypothesis that Helisoma neurones can sprout in response to a change in blood osmolarity. This was achieved by exposing snails to hyperosmotic and hyposmotic pond water which has known effects on blood osmolarity (Khan & Saleuddin, 1979).
Measurement of Colloid Osmotic Pressure of Microlitre and Sub-Microlitre Volumes
Authors: Riegel J. A.
Published: April 2021

This paper describes two devices for the measurement of colloid osmotic pressure (COP) in volumes of fluid of 0·5 μl or larger. Both devices are based on a design introduced by Hansen (1961) in which COP is measured directly. An ultrafiltration membrane is clamped over a fluid-filled reference chamber which communicates with the sensitive surface of a blood pressure transducer. When colloid-containing fluid is placed on the upper surface of the membrane, fluid is drawn out of the reference chamber, lowering the hydrostatic pressure there. If the membrane is impermeable to the colloid, the pressure drop in the reference chamber is directly proportional to the COP of the colloid-containing fluid.
Feeding Rank and Brain Serotonergic Activity in Rainbow Trout Oncorhynchus Mykiss
Authors: Winberg Svante , Carter Cris G. , McCarthy Ian D. , He Zhong-Yang , Nilsson Göran E. , Houlihan Dominic F.
Published: April 2021

Two methods for assessing the status of an individual rainbow trout Oncorhynchus mykiss within a group hierarchy, radiographic determination of individual food intake and analysis of brain serotonergic activity, were compared. The results showed that individual food intake, measured as the average share of the group meal, and brain serotonergic activity, measured as brain levels of 5-hydroxyindoleacetic acid (5-HIAA) or as 5-HIAA/5-HT (serotonin) ratios, were inversely correlated with each other, suggesting that both methods could be used as indicators of the position of the rainbow trout in a dominance hierarchy. In addition, specific growth rate correlated significantly with brain 5-HIAA/5-HT ratios.

The results indicate that the increase in brain 5-HIAA/5-HT ratios in subordinate individuals is caused by an increased use (release) of 5-HT in these fish, and not by an increase in the level of tryptophan, the amino acid precursor of 5-HT. The relationships between social rank, food intake, growth, stress and brain serotonergic activity of fish in a social hierarchy are discussed.
Magnetic orientation of snow buntings (Plectrophenax nivalis), a species breeding in the high Arctic: passage migration through temperate-zone areas
Authors: Sandberg R , Pettersson J
Published: April 2021

Orientation tests were conducted with snow buntings (Plectrophenax nivalis) exposed to artificially manipulated magnetic fields, during both spring and autumn migration. Experiments were run under clear sunset skies and under simulated complete overcast. The birds closely followed experimental shifts of the magnetic fields during both seasons regardless of whether they had access to celestial cues. Clear-sky tests in vertical magnetic fields resulted in a significant bimodal orientation, the directionality of which was almost identical during spring and autumn. When the snow buntings were deprived of celestial directional information and tested in vertical magnetic fields, they failed to show any statistically significant mean directions in either spring or autumn. The results demonstrate that snow buntings possess a magnetic compass and suggest that magnetic cues are of primary importance for their migratory orientation while on passage through temperate-zone areas. However, the axial orientation in vertical magnetic fields under clear skies may indicate an involvement of celestial cues as an auxiliary source of directional information.
Correlations Between Call Characteristics and Morphology in Male Cricket Frogs (Acris Crepitans)
Authors: Mcclelland Blinda E. , Wilczynski Walter , Ryan Michael J.
Published: April 2021

We investigated the relationships among spectral and temporal advertisement-call characteristics and the sizes of the laryngeal and ear components thought to underlie the generation and reception of species-specific vocalizations in male cricket frogs (Acris crepitans). We tested the predictions that the volumes of the structural elements necessary for acoustic communication would be correlated with various parameters of the vocalizations. The anatomy of laryngeal and ear structures was reconstructed from serial sections of the heads of male cricket frogs of two subspecies collected from several sites across the range of this species in Texas, USA. The relationships among the anatomy and call parameters were assessed using several univariate and multivariate analyses. Highly significant univariate correlations among the laryngeal components suggest that the temporal and spectral characteristics of the calls are not independently produced. Dominant frequency correlates strongly with most of the other call and morphological characteristics. Removing body size effects, however, removes the relationship between dominant frequency and the volume of the whole larynx and ear. This is also the case for call pulse rate, indicating that for this species both spectral and temporal call parameters are biomechanically related to laryngeal size which is, in turn, largely mediated by body size. General body size effects might also explain the existence of significant relationships between ear size and temporal characteristics of the call that probably do not have a functional basis.
Mechanical Efficiency and Efficiency of Storage And Release Of Series Elastic Energy In Skeletal Muscle During Stretch–Shorten Cycles
Authors: Ettema G. J. C.
Published: April 2021

The mechanical energy exchanges between components of a muscle–tendon complex, i.e. the contractile element (CE) and the series elastic element (SEE), and the environment during stretch–shorten cycles were examined. The efficiency of the storage and release of series elastic energy (SEE efficiency) and the overall mechanical efficiency of the rat gastrocnemius muscle (N=5) were determined for a range of stretch–shorten contractions. SEE efficiency was defined as elastic energy released to the environment divided by external work done upon the muscle–tendon complex plus internal work exchange from the CE to the SEE. Mechanical efficiency is external work done by the muscle–tendon complex divided by the external work done upon the muscle–tendon complex plus work done by the CE.

All stretch–shorten cycles were performed with a movement amplitude of 3 mm (6.7 % strain). Cycle frequency, duty factor and the onset of stimulation were altered for the different cycles. SEE efficiency varied from 0.02 to 0.85, mechanical efficiency from 0.43 to 0.92. SEE efficiency depended on the timing of stimulation and net muscle power in different ways. Mechanical efficiency was much more closely correlated with net power.

The timing of muscle relaxation was crucial for the effective release of elastic energy. Simulated in vivo contractions indicated that during rat locomotion the gastrocnemius may have a role other than that of effectively storing elastic energy and generating work.

Computer simulations showed that the amount of series elastic compliance can affect the internal energetics of a muscle contraction strongly without changing the muscle force generation dramatically.
Fictive locomotion induced by octopamine in the earthworm
Authors: Mizutani Kenji , Ogawa Hiroto , Saito Junichi , Oka Kotaro
Published: April 2021

We investigated the function of octopamine (OA) as a motor pattern inducer in the earthworm Eisenia fetida. We used semi-intact preparations, consisting of 20 sequential segmental ganglia of the ventral nerve cord (VNC) together with the body wall from the middle of the animal. Bath-application of 10–4 mol l–1 OA to the semi-intact preparation induced phasic muscle contractions, which are consistent with crawling. In the isolated VNC, OA induced bursts of motor neuron activity in the first lateral nerves. Burst frequency increased with OA concentration, with a large increase in activity observed in the range 10–6–10–4 mol l–1. At 10–4 mol l–1, the coefficient of variation of burst periods (BPs) was smaller than that seen upon application of OA at other concentrations, which is indicative of rhythmic bursts. These rhythmic bursts propagated along the VNC from the anterior to posterior, with a propagation velocity ranging from 60 to 110 mm s–1. This velocity is consistent with the propagation velocity of muscle contraction during crawling behavior in the intact earthworm. From these results, we conclude that fictive crawling motor patterns are observed at 10–4 mol l–1 OA, and that OA can induce rhythmic bursts in the isolated VNC of the earthworm.
Copper metabolism in actively growing rainbow trout (Oncorhynchus mykiss): interactions between dietary and waterborne copper uptake
Authors: Kamunde Collins , Grosell Martin , Higgs Dave , Wood Chris M.
Published: April 2021

Juvenile rainbow trout Oncorhynchus mykiss were exposed to diets with low (12.6 nmol g–1), normal (50.4 nmol g–1) or elevated (4437.5 nmol g–1) Cu concentrations in combination with either low (5.8 nmol l–1) or normal (48.5 nmol l–1) waterborne Cu levels over a 50-day period, during which body mass increased up to fivefold. A nutritional requirement for Cu was demonstrated based on growth response and whole body and tissue Cu status. Simultaneous low Cu levels in both the water and the diet depressed growth by 31 % over 7 weeks. There were reductions in both specific growth rate (SGR, 1.95 versus 2.55 % day–1) and food conversion efficiency (FCE, 53–59 % versus 75–80 %) over weeks 0–4, but these effects disappeared in weeks 4–7. Elevated concentrations of dietary Cu did not affect SGR or FCE. Low levels of dietary and waterborne Cu decreased, and high levels of dietary Cu increased, the Cu concentrations in whole body, liver, carcass, gut and gills. Copper levels in the liver strongly reflected the exposure conditions with a corresponding fivefold decrease and a 22-fold increase in Cu concentration. Restricting available Cu caused an exponential decline in whole body Cu concentration from 0.0175 to 0.0069 μmol g–1 and increased the uptake of waterborne Cu (measured with 64Cu) by the gills. Conversely, high levels of dietary Cu caused a linear increase in whole body Cu concentration to approximately 0.170 μmol g–1 and depressed the uptake of waterborne Cu. Waterborne Cu uptake contributed the majority (60 %) of the body’s Cu accumulation under Cu-deficient conditions while dietary Cu contributed the majority (99 %) at high dietary levels of Cu. True bioavailability of dietary Cu decreased with increasing levels of dietary Cu concentration, although the absolute amount retained increased. These findings demonstrate an important interaction between dietary and waterborne Cu uptake in fish and provide compelling evidence of a key role for the gill in Cu homeostasis.
Studies on Possible Serological Blocks to Species Hybridization in Poultry
Authors: Ryle Margaret
Published: April 2021

It is suggested that normal heteroantibodies may contribute to the difficulties of species hybridization by damaging heterologous spermatozoa and/or by reducing hybrid embryonic viability. Techniques are described for titrating yolk antibody and for agglutination tests with fowl spermatozoa. Plasma samples from several breeds of chickens were titrated with turkey erythrocytes in order to study the variability of normal heteroagglutinin titres. Turkey spermatozoa were agglutinated in vitro by chicken plasma. Absorption tests showed that the same antigens, reacting with the normal heteroagglutinin of chicken plasma, occur on turkey spermatozoa and turkey erythrocytes. Further work is required on the agglutination of chicken sperm by turkey plasma. Low titres of anti-turkey-erythrocyte agglutinin in the blood of domestic hens did not promote interspecific fertility. Immunization of domestic hens with the erythrocytes of the cockerel with which they were mated did not induce infertility. It is nevertheless considered that an investigation of normal incomplete antibody in relation to inter- and intraspecific fertility might prove fruitful. Normal heteroagglutinins occur in turkey and chicken yolk. The titre of anti-turkey agglutinin in chicken yolk is very close to that in the hen’s plasma. Antigens reacting with the normal heteroagglutinin of turkey plasma appear on chick embryo erythrocytes after 4–5 days’ incubation; there seems to be little quantitative increase thereafter. They occur on both primitive and definitive erythrocytes. Normal anti-turkey agglutinin derived from the egg yolk was detected in the blood plasma of a few chick embryos after 13 days’ incubation or more. The latter results are discussed in relation to other published work both on the effects of antisera on embryogenesis and on the ontogeny of antigenic properties.
On A Peculiar Type of Intersexuality in the Guinea-Pig
Authors: Lipschutz Alexander
Published: April 2021

An abnormal condition of the external genital organs in 16 otherwise normal female guinea-pigs is described. They possessed an hypertrophied penis-like clitoris and horny styles similar to those in the intromittent sac of the normal male penis.

The abnormalities are often asymmetrical, the clitoris and the horny style on one side being more developed than on the other. They may even be absent on one side.

It is suggested that the malformation is a peculiar type of “partial somatic intersexuality,” the external genital organs resembling those in the male guinea-pig.

The condition is identical with that described in the castrated female guineapig experimentally masculinised by testicular transplantation.

There was no indication of the ovaries producing simultaneously female and male sexual hormones :

The ovaries were histologically normal. The ovaries when engrafted into castrated males produced the typical female hormonic effect on the mammary glands and had no influence on the penis or on the horny styles. The clitoris and the horny styles of the intersexual females were not affected by removal of the ovaries, whereas in the male removal of the testes caused a pronounced regression of the horny styles even in fully grown animals. The horny styles when cut regenerated even after removal of the ovaries ; there is never a regeneration in the castrated male, but only in the normal male.

The question is discussed whether the described type of intersexuality might be a case of “successive hormonic intersexuality,” both kinds of sexual hormones having been produced simultaneously for a certain time whereas at a later stage only female hormones were secreted. The hypertrophied clitoris and the horny styles would then be considered as “fixed” sex characters persisting after the disappearance of the male sexual hormones. The problem of fixation of sex characters by sexual hormones is considered on experimental lines. The facts observed are rather against the suggestion that the intersexuality described is a case of successive hormonic intersexuality.

Other possibilities of explaining the morphogenetic basis of this peculiar type of intersexuality are also discussed.

The intersexuality described is of an hereditary nature.
Studies on the Influence of the Surrounding Medium on the Activity of Cells in Tissue Culture
Authors: Willmer E. N.
Published: April 2021

A suitable saline medium for the survival of intestinal tissues from the embryo chick was found to be the following: NaCl 0.8 per cent., KCl 0.025 per cent., CaCl2 0.025 per cent., NaHCO3 0.02 per cent., glucose 0.8 per cent. In this medium the concentration of NaCl could be varied from 0.4 per cent to 1 per cent. and still allow of an active migration of cells to take place. Outside these limits migration occurred fairly freely as far as 0.2 per cent. and 1.2 per cent., but was then either reduced in extent or abnormal in character. When the concentration of NaCl was low the cells became abnormal and vacuolated. This is assumed to be due to low osmotic pressure and not specifically to lack of NaCl. Fibroblasts grew most extensively when the sodium chloride concentration was 0.7 per cent. This was considered to be due to the stimulus given to amoeboid movement by hypotonic solutions, while the cells were still in a fairly normal condition. For good epithelial growth a salt concentration of 0.9 per cent. was found to be most satisfactory. A higher percentage of cultures showed epithelial growth in 0.7 per cent. solutions, but the extent was greatest in 0.9 per cent. The hypotonic solution at first stimulated the cells to migrate, but at the same time caused some abnormality, as they always perished before those in 0.9 per cent. NaCl media. Glucose was found to be a necessary constituent and, other things being equal, the amount of cell migration was found to be directly dependent on the amount of glucose present, up to a concentration of I per cent. Above that limit, glucose appeared to become slightly toxic. 0.9 per cent. NaCl can therefore be regarded as the optimum concentration of this salt in an otherwise normal medium, but in these cultures the amount of glucose necessary to support continued growth leads to too high an osmotic pressure, so that for general purposes the ideal standard solution contains 0.8 per cent. NaCl and 0.8 per cent, glucose. In this solution growth is steady and normal throughout.
An Examination of Nostoc for Nuclear Materials
Authors: Mockeridge F. A.
Published: April 2021

The literature concerning the presence or absence of nuclear material in the cyanophycean cell is too well known to need review ; it is sufficient to say that there is a consensus of opinion in favour of the presence of granules of chromatin, or what Miss Acton (1914) and others prefer to call “metachromatin” (a substance of less complex organisation than chromatin), scattered through the central region of the cell. Since chromatin is of the nature of a nucleo-protein, it seemed worth while investigating the Cyanophyceae for nucleic acid content, in order to determine whether any appreciable quantities of this substance could be extracted.
Campaniform Sensilla on the Tactile Spines of the Legs of the Cockroach*
Authors: Chapman K. M.
Published: April 2021

The failure to record receptor potentials from cut ends of the large tactile spines of the legs of the cockroach Periplaneta americana has prompted a histological and electrophysiological search for the sensory unit of these tactile spines. Histological sections, made with a cuticle-softening fixative containing tetrahydrofuran, and cleared whole-cuticle preparations reveal a single campaniform sensillum in the thick cuticular wall of the spine at its junction with the soft cuticle of its socket. Punctate stimulation in the same region reveals a highly mechanosensitive region similar in size, shape, orientation and location to the campaniform sensillum. Movement of the spine during after-discharges which sometimes follow punctate stimulation does not produce a second impulse train, but modulates the after-discharge. It is concluded that the campaniform sensillum is the sensory structure of the tactile spines of the cockroach, and is responsible for the normal discharge that occurs on contact with the spine. Strong stimulation causes a failure of the afferent discharge, resembling the ‘overstretch’ phenomena seen with other mechanoreceptors. Spike wave-form analysis suggests that impulse initiation may occur at more than one site on the sensory neuron or in more than one manner, and includes the possibility of a delayed, non-propagated discharge of the soma of the sensory neuron.
Accessibility of the Central Nervous Connectives ofAnodonta Cygneato a Compound of Large Molecular Weight
Authors: Lane N. J. , Treherne J. E.
Published: April 2021

Ultrastructural observations on the uptake of an exogenous tracer substance, horseradish peroxidase (M.W. 40,000), have shown that this large molecule can penetrate the neural lamella in intact cerebro-visceral connectives of the lamellibranch, Anodonta cygnea. Peroxidase molecules were also observed to penetrate between the intercellular clefts formed by adjacent membranes of the underlying peripheral glial cell layer and to move extensively into the underlying extracellular spaces. These observations confirm the results of previous electrophysiological, radio-isotopic and ultrastructural investigations indicating that a relatively rapid exchange of water-soluble ions and molecules occurs between the blood, or bathing medium, and the extracellular fluid bathing the axon surfaces in intact connectives.
Convergence of olfactory inputs from both antennae in the brain of the honeybee
Authors: Suzuki H.
Published: April 2021

Electrical activities of the olfactory neurones in the brain of the honeybee were investigated. Odorous stimuli were given to each antenna separately or to both simultaneously. The inputs from the antennae affected both the impulse frequency and the latency of the olfactory interneurones in the protocerebrum. The predominant response was to the stimulation of the ipsilateral antenna. Input from the contralateral antenna produced mainly excitatory effects, although a few inputs gave inhibitory effects.

No particular relationships between the loci of the units in the brain and the types of responses produced were found. Most of the units were located in the protocerebral lobe and in the central commissure. The units in the deutocerebrum responded only to the stimulation of the ipsilateral antenna, and the magnitude of response and the latency were not different with respect to unilateral or bilateral stimulation of the antennae. Differences in latency between unilateral and bilateral stimulation were observed in some of the units in the protocerebrum.

Neural models which explain these phenomena are postulated.
The relationship between transepithelial sodium movement and potential difference in the larva of Camptochironomus tentans (Fabr.) and some observations on the accumulation of other ions
Authors: Wright D.A.
Published: April 2021

In fourth instar larvae of Camptochironomus tentans, net sodium uptake from 2 mm-NaCl has an elect ogenic component. During net uptake the transepithelial potential (TEP) alters from a value of ˜ – 40 mV (sign refers to haemolymph), in depleted animals, to ˜0 mV. The TEP in depleted larvae is dependent upon external sodium concentration above about 1 mm-Na+, becoming increasingly electropositive (haemolymph relative to medium) at high sodium concentrations. This effect is exaggerated in Na2SO4 compared with NaCl. At an external concentration of 2 mm-NaCl, chloride is carried by an electroneutral mechanism, probably a closely coupled Cl−/ anion exchange. However, it is possible that chloride transport could become somewhat electrogenic at higher concentrations.

Lithium competes with sodium for the electrogenic pump.

Observed TEPs differ greatly from those required to maintain passively the haemolymph concentrations of sodium and chloride.
Directional Hearing in the Japanese Quail (Coturnix Coturnix Japonica)
Authors: Hill K. G. , Lewis D. B. , Hutchings M. E. , Coles R. B.
Published: April 2021

The auditory tympana in the quail, Coturnix coturnix japonica (L.) are internally coupled by an interaural air space. Unilaterally applied sound causing vibration of the ipsilateral tympanum is conducted through the interaural cavity to the inside surface of the contralateral tympanum. In a free sound field at frequencies up to 3150 Hz, sound pressure at the external surface of the tympanum contralateral to the source is within about 3 dB of the pressure exterior to the ipsilateral tympanum. Sound pressures developed at the inner surfaces of the tympana are of similar amplitude to the external pressures at several frequencies in the range 800–6300 Hz. In addition, pressure at each side of the tympanum ipsilateral to the source are generally out of phase, whereas pressures at each side of the contralateral tympanum are relatively close to the same phase. From measurements of amplitude and phase of the interacting pressures at the tympanum, the calculated driving pressure at the ipsilateral tympanum exceeds that at the contralateral tympanum by 10–20 dB over a range of frequencies. The auditory tympana in quail have considerable inherent directionality, therefore, due to their function as pressure-gradient receivers. Anatomical analogies with anurans and reptiles indicate that they derive directional hearing from the same acoustic mechanism that operates in the quail.
Body Fluid Pools, Kidney Function, and Acid-Base Regulation in the Freshwater Catfish Ictalurus Punctatus*
Authors: Cameron James N.
Published: April 2021

Resting catfish excreted a urine with electrolyte concentrations about that of blood, with very low concentrations of ammonia and lactic acid, only slightly acid pH, and a small resultant net base excretion.

At 26 °C, the intracellular pH was normally 0·51 units lower than the extracellular pH. Both were depressed following the onset of hypercapnia, but there was compensation for both by 24 h, so that pHi was near control values. Consequently the whole body CO2 pool increased from 195 to 4·77 m-equiv kg−1 during hypercapnia, with about 1·50 m-equiv by active means, and the other 1·32 by passive (non-bicarbonate) buffering.

The renal response to hypercapnic acidosis was to switch from a small net base excretion to a net acid excretion, which persisted for up to 10 h, and accounted for about 14% of the total active bicarbonate compensation.

There was no statistically significant renal response to an infused HC1 load, but the whole body base excretion rate declined so as to indicate that about 25 % of the infused load was excreted in the first 2 h, presumably by the gills.

The catfish kidney appears to participate in acid-base regulation in a sig- nificant, but quantitatively minor way, implying that the gills are the principal site of ion transfer in regulating the whole body SID.
Haemoglobin-Oxygen Binding Properties in the Blood of Xenopus Laevis, With Special Reference to the Influences of Aestivation and of Temperature and Salinity Acclimation
Authors: Jokumsen Alfred , Weber Roy E.
Published: April 2021

The oxygen equilibrium properties of blood and of solutions of haemoglobin from Xenopus laevis are reported. At pH 7·6 the oxygen affinity of the blood, expressed as half saturation oxygen tension (P50) amounts to 27·0 mm and 13·7 mmHg (3·60 and 1·83 kPa) when measured at 25 and 10 °C, while the Bohr factor (Δ log P50/ΔpH) was – 0·40, and the Hill’s cooperativity coefficient, n, averaged 2·1. These data reflect an overall heat of oxygenation, AH, of – 7·9 kcal. mol−1, which decreased to – 6·3 kcal. mol−1 when the live animals were acclimated to each measuring temperature. Xenopus blood showed a high O2 capacity (15 vol.%) compared to that of other amphibians.

Acclimation to water of increased salinity (12‰), and aestivation, raised blood O2 affinity; at 25 °C and pH 7·6, P50 decreased to 21·1 and 25·2 mmHg (2·81 and 3·36 kPa), respectively. These changes were concomitant with increases in the blood levels of urea. In contrast to NaCl and ATP, urea increased O2 affinity of the purified haemoglobin, suggesting that oxygenation-linked binding to haemoglobin is involved in the modulations of the blood O2 affinity during aestivation and acclimation to salt water.

Xenopus haemoglobin consists of two components. The major component is electrophoretically anodal, and has O2 binding properties similar to those of the haemolysate; the minor component is cathodal, and shows extremely low P50, pH sensitivity and cooperativity.
Rhythmic Electrical Activity in Stomach and Intestine of Toad
Authors: Mangel Allen , Prosser C. Ladd
Published: April 2021

The intact stomach of the toad initiates rhythmic slow-spikes of 5–15 s duration and frequency of 3–5 min-1. The spontaneous electrical waves originate in the longitudinal muscle layer; isolated circular muscle is quiescent. Aboral conduction velocity is 0·12–0·9 mm s-1. Reduction of external sodium concentration from 89·5 to 15 mM produced no effect on slow spikes, although further reduction to 1·5 mM increased frequency and decreased amplitude. Slow-spikes were unaffected by ouabain or by incubation in potassium-free solution. When calcium in the medium was reduced, slow-spike amplitude and frequency decreased. Slow-spikes exhibited a change in amplitude of 16 mV per decade change in Ca02+; slow-spikes were eliminated at 10−8 M and by blockers of calcium conductance channels.

Intact intestine of toad demonstrated slow-waves which resembled those of mammalian intestine. These were sensitive to changes in external sodium and were eliminated by 1 × 10−4 M ouabain.

It is suggested that rhythmic slow-spikes of longitudinal smooth muscle of amphibian stomach may result from periodic changes in Ca conductance whereas endogenous electrical waves of intestine may result from rhythmic extrusion of sodium.
South-Seeking Magnetic Bacteria
Authors: Kirschvink J. L.
Published: April 2021

During the past few years, a wide variety of living organisms have been found which biologically synthesize the ferrimagnetic mineral, magnetite (Fe3O4) First discovered as a biogenic material in the teeth of a primitive mollusc, the chiton (Polyplacophora, Lowenstam 1962), it has since been found as an organic precipitate in magnetically sensitive honey bees (Gould, Kirschvink & Deffeyes, 1978), homing pigeons (Walcott, Gould & Kirschvink, 1979) and bacteria (Frankel, Blakemore & Wolfe, 1979). In all of these organisms (except the chiton), the magnetite is apparently used to orient with or detect the direction and intensity of the earth’s magnetic field (Kirschvink, 1979; Kirschvink & Gould, in review).
Status of Surgical Management of Borderline Ovarian Tumors in France: are Recommendations Being Followed? Multicentric French Study by the FRANCOGYN Group
Authors: Lecointre Lise , Bund Virginie , Sangnier Eva , Ouldamer Lobna , Bendifallah Sofiane , Koskas Martin , Bolze Pierre-Adrien , Collinet Pierre , Canlorbe Geoffroy , Touboul Cyril , Huchon Cyrille , Coutant Charles , Faller Emilie , Boisramé Thomas , Gantzer Justine , Demarchi Martin , Lavoué Vincent , Akladios Chérif
Published: April 2021

Background

Borderline ovarian tumors (BOTs) are tumors with a favorable prognosis but whose management by consensus is essential to limit the risk of invasive recurrence. This study aimed to conduct an inventory of surgical practices for BOT in France and to evaluate the conformity of the treatment according to the current French guidelines.

Methods

This retrospective, multicenter cohort study included nine referral centers of France between January 2001 and December 2018. It analyzed all patients with serous and mucinous BOT who had undergone surgery. A peritoneal staging in accordance with the recommendations was defined by performance of a peritoneal cytology, an omentectomy, and at least one peritoneal biopsy.

Results

The study included 332 patients. A laparoscopy was performed in 79.5% of the cases. Treatment was conservative in 31.9% of the cases. The recurrence rate was significantly increased after conservative treatment (17.3% vs 3.1%; p < 0.001). Peritoneal cytology was performed for 95.5%, omentectomy for 83.1%, and at least one biopsy for 82.2% of the patients. The overall recurrence rate was 7.8%, and the recurrence was invasive in 1.2% of the cases. No link was found between the recurrence rate and the conformity of peritoneal staging. The overall rate of staging noncompliance was 22.9%.

Conclusion

The current standards for BOT management seem to be well applied.
Development of Off-On Switching 19F MRI Probes for Cathepsin K Activity Detection
Authors: Konishi Yuki , Okunishi Atsuya , Sugihara Fuminori , Nakamura Tatsuya , Akazawa Kazuki , Minoshima Masafumi , Kikuchi Kazuya
Published: April 2021

Cathepsin K is a protease expressed in osteoclasts that degrades bone tissue, such as type I collagen fibers. Overexpression of cathepsin K is involved in osteoporosis, rheumatoid arthritis, and bone metastasis. Therefore, detecting cathepsin K activity is important for understanding the mechanism of these diseases and developing new drugs. However, current chemical probes cannot be employed for the detection of cathepsin K activity in animal deep-tissue. In this study, we developed novel 19F magnetic resonance imaging (MRI) probes (FLAME-(Gd-X), X = Acp, Deg, Deg2) to detect cathepsin K. In FLAME-(Gd-X), the Gd3+ complex was modified on the surface of perfluorocarbon-encapsulated silica nanoparticles through cathepsin K substrate and three different hydrophobic/hydrophilic linkers. The 19F NMR signal intensities of these probes were suppressed by the paramagnetic relaxation enhancement (PRE) effect of the Gd3+ complexes. The 19F MRI signal intensities of FLAME-Gd-Acp and FLAME-Gd-Deg specifically increased with the substrate cleavage by cathepsin K. The 19F MRI probes based on the PRE effect can be applied to the in vivo detection of cathepsin K activity.
Dates fruits effects on blood glucose among patients with diabetes mellitus: A review and meta-analysis
Authors: Mirghani Hyder Osman
Published: April 2021

Background & Objective: Dates fruit is known for its great nutritional value and two to three servings of dates fruit/day are beneficial for patients with diabetes. However, some may advice against this cheap and widely available fruit consumption. Besides, 12% of the population Worldwide are either suffering or are at risk of developing diabetes, but no previous meta-analysis has assessed this important issue. Thus, the study aimed to investigate the effects of date’s fruit on glycemia among patients with diabetes.

Methods: A systematic literature search was conducted in PubMed, Medline, EBSCO, Cochrane, and Google Scholar databases for trials published in English from the first published article up to December 2020. The following keywords were used: “dates fruit and glycemic control”, “dates fruit and blood glucose”, “dates fruit and HbA1c” without limitations regarding the date of publication.

Results: Out of the 942 references identified, only 10 cohorts from five full texts were included, a reduction of Fasting plasma glucose (FPG), odd ratio, -24.79, 95% CI=-34.75, -14.83 P =0.002. I2 for heterogeneity=79%, P <0.00001 and postprandial plasma glucose (PPPG), odd ratio -28.19, 95% CI=-60.66-4.29, P =<0.0001. I2 for heterogeneity=92%, P=0.09) was observed. While the effect on HbA1c was neutral, odd ratio, -.20, 95% CI=-.46 -.06, P=0.13. I2 for heterogeneity=0. %, P=0.55.

Conclusion: Dates fruit was beneficial regarding glycemic control among patients with diabetes, physician may not need to restrict its use among patients with diabetes. The small number of the included studies and the heterogeneity observed in PPPG and FPG sub-analysis limited the current results. Further trials assessing the glycemic indices of various types of dates fruit are needed.

doi: https://doi.org/10.12669/pjms.37.4.4112

How to cite this:Mirghani HO. Dates fruits effects on blood glucose among patients with diabetes mellitus: A review and meta-analysis. Pak J Med Sci. 2021;37(4):1230-1236. doi: https://doi.org/10.12669/pjms.37.4.4112

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Incidence of acute pulmonary embolism among patients hospitalized with COVID-19: a systematic review and meta-analysis
Authors: Munner Mohamed S. , Ritchie Charles A. , Elkhidir Ibrahim H. , Mohammadat Doaa T. , Ahmed Hussein J. , Altayeb Khalid A. , Yassin Rawan Z. , Hassan Riyan M. , Hamad Saada A. , Nimir Mohammed , Hamid Osman S. , Johnson Margaret M. , Narula Tathagat , Erben Young , Tawk Rabih G. , Miller David A. , Gupta Vivek , Devcic Zlatko , Freeman William D. , Toskich Beau B.
Published: April 2021

Background: Coronavirus disease 2019 (COVID-19) is a global pandemic, which is associated with venous thromboembolism and pulmonary embolism (PE). This study aimed to estimate the pooled incidence of PE among patients hospitalized with COVID-19 within the published literature.

Methods: This systematic review and meta-analysis was performed according to PRISMA guidelines. An electronic search using MEDLINE /PubMed, ScienceDirect, Cochrane, and OpenGray databases was conducted May 19th, 2020. Eligible studies included sufficient data to calculate the incidence of PE diagnosed during hospitalization in patients with COVID-19. Case reports were excluded. Quality was assessed using the Newcastle-Ottawa scale (observational cohort and case-control), AXIS tool (cross-sectional), and quality assessment tool (case series). Demographics and PE incidence data were extracted from the included studies and analyzed with R language. The pooled incidence of PE in patients hospitalized with COVID-19 was calculated.

Results: The database search identified 128 records. Ten observational studies were eligible and were included in the meta-analysis with a total of 1722 patients (mean age= 63.36). .The incidence of PE was noted to be higher in males. The D-dimer levels were

specified between PE group and non-PE group in only three studies, while the remaining either reported it improperly or had missing data.The pooled PE incidence in patients hospitalized with COVID-19 was 17% (95% CI: 0.1-0.26). There was a high degree of study heterogeneity (I2 = 94%, p<0.01).

Conclusion: The pooled PE incidence in patients hospitalized with COVID-19 is 17%. This increased incidence is greater than that previously reported in the general population of non-COVID-19. Attention and further investigation of this risk is warranted.
Bioimage analysis workflows: community resources to navigate through a complex ecosystem
Authors: Paul-Gilloteaux Perrine , Tosi Sébastien , Hériché Jean-Karim , Gaignard Alban , Ménager Hervé , Marée Raphaël , Baecker Volker , Klemm Anna , Kalaš Matúš , Zhang Chong , Miura Kota , Colombelli Julien
Published: April 2021

Workflows are the keystone of bioimage analysis, and the NEUBIAS (Network of European BioImage AnalystS) community is trying to gather the actors of this field and organize the information around them.  One of its most recent outputs is the opening of the F1000Research NEUBIAS gateway, whose main objective is to offer a channel of publication for bioimage analysis workflows and associated resources. In this paper we want to express some personal opinions and recommendations related to finding, handling and developing bioimage analysis workflows. 

The emergence of "big data” in bioimaging and resource-intensive analysis algorithms make local data storage and computing solutions a limiting factor. At the same time, the need for data sharing with collaborators and a general shift towards remote work, have created new challenges and avenues for the execution and sharing of bioimage analysis workflows.

These challenges are to reproducibly run workflows in remote environments, in particular when their components come from different software packages, but also to document them and link their parameters and results by following the FAIR principles (Findable, Accessible, Interoperable, Reusable) to foster open and reproducible science.

In this opinion paper, we focus on giving some directions to the reader to tackle these challenges and navigate through this complex ecosystem, in order to find and use workflows, and to compare workflows addressing the same problem. We also discuss tools to run workflows in the cloud and on High Performance Computing resources, and suggest ways to make these workflows FAIR.