bluuebunny/crossref_metadata_2025 huggingface dataset:
Death by small forces: a fracture and fatigue analysis of wave-swept macroalgae
Authors: Mach Katharine J. , Hale Benjamin B. , Denny Mark W. , Nelson Drew V.
Published: June 2007

Wave-swept macroalgae are subjected to large hydrodynamic forces as each wave breaks on shore, loads that are repeated thousands of times per day. Previous studies have shown that macroalgae can easily withstand isolated impositions of maximal field forces. Nonetheless, macroalgae break frequently. Here we investigate the possibility that repeated loading by sub-lethal forces can eventually cause fracture by fatigue. We determine fracture toughness, in the form of critical strain energy release rate, for several flat-bladed macroalgae, thereby assessing their resistance to complete fracture in the presence of cracks. Critical energy release rates are evaluated through single-edge-notch, pull-to-break tests and single-edge-notch, repeated-loading tests. Crack growth at sub-critical energy release rates is measured in repeated-loading tests, providing a first assessment of algal breakage under conditions of repeated loading. We then estimate the number of imposed waves required for un-notched algal blades to reach the point of complete fracture. We find that, if not checked by repair, fatigue crack growth from repeated sub-lethal stresses may completely fracture individuals within days. Our results suggest that fatigue may play an important role in macroalgal breakage.
Physiological regulation of glucose transporter (GLUT4) protein content in brown trout (Salmo trutta) skeletal muscle
Authors: Díaz Mònica , Capilla Encarnación , Planas Josep V.
Published: June 2007

In brown trout, red and white skeletal muscle express the insulin-regulatable glucose transporter 4 (btGLUT4). We have previously shown that the mRNA expression of btGLUT4 in red muscle, but not white muscle, is altered under experimental conditions designed to cause changes in the plasma levels of insulin, such as fasting, insulin and arginine administration. In order to determine whether changes of btGLUT4 expression at the mRNA level are correlated with changes at the protein level, we performed in vivoexperiments to alter blood insulin concentrations and determined the abundance of btGLUT4 protein in trout red and white skeletal muscle by immunoblotting using an antibody to salmon GLUT4. In the present study we show that btGLUT4 protein content in red muscle decreases after fasting and increases after insulin administration. By contrast, btGLUT4 protein content in white muscle decreases after fasting but is not affected by insulin treatment. Our results show a good correlation between the changes observed in btGLUT4 protein and the previously reported changes in mRNA levels in response to alterations in circulating insulin, indicating that the regulation of btGLUT4 in brown trout takes place predominantly in the red skeletal muscle.
Variations in motor unit recruitment patterns occur within and between muscles in the running rat (Rattus norvegicus)
Authors: Hodson-Tole E. F. , Wakeling J. M.
Published: June 2007

Motor units are generally considered to follow a set, orderly pattern of recruitment within each muscle with activation occurring in the slowest through to the fastest units. A growing body of evidence, however, suggests that recruitment patterns may not always follow such an orderly sequence. Here we investigate whether motor unit recruitment patterns vary within and between the ankle extensor muscles of the rat running at 40 cm s-1 on a level treadmill. In the past it has been difficult to quantify motor unit recruitment patterns during locomotion; however, recent application of wavelet analysis techniques has made such detailed analysis of motor unit recruitment possible. Here we present methods for quantifying the interplay of fast and slow motor unit recruitment based on their myoelectric signals. Myoelectric data were collected from soleus, plantaris and medial gastrocnemius muscles representing populations of slow, mixed and fast fibres, respectively, and providing a good opportunity to relate myoelectric frequency content to motor unit recruitment patterns. Following wavelet transformation, principal component analysis quantified signal intensity and relative frequency content. Significant differences in signal frequency content occurred between different time points within a stride (P<0.001). We optimised high- and low-frequency wavelets to the major signals from the fast and slow motor units. The goodness-of-fit of the optimised wavelets to the signal intensity was high for all three muscles (r2>0.98). The low-frequency band had a significantly better fit to signals from the soleus muscle (P<0.001), while the high-frequency band had a significantly better fit to the medial gastrocnemius(P<0.001).
Identification and cardiotropic actions of sulfakinin peptides in the American lobster Homarus americanus
Authors: Dickinson Patsy S. , Stevens Jake S. , Rus Szymon , Brennan Henry R. , Goiney Christopher C. , Smith Christine M. , Li Lingjun , Towle David W. , Christie Andrew E.
Published: June 2007

In arthropods, a group of peptides possessing a–Y(SO3H)GHM/LRFamide carboxy-terminal motif have been collectively termed the sulfakinins. Sulfakinin isoforms have been identified from numerous insect species. In contrast, members of this peptide family have thus far been isolated from just two crustaceans, the penaeid shrimp Penaeus monodon and Litopenaeus vannamei. Here, we report the identification of a cDNA encoding prepro-sulfakinin from the American lobster Homarus americanus. Two sulfakinin-like sequences were identified within the open-reading frame of the cDNA. Based on modifications predicted by peptide modeling programs, and on homology to the known isoforms of sulfakinin, particularly those from shrimp, the mature H. americanus sulfakinins were hypothesized to be pEFDEY(SO3H)GHMRFamide (Hoa-SK I) and GGGEY(SO3H)DDY(SO3H)GHLRFamide (Hoa-SK II). Hoa-SK I is identical to one of the previously identified shrimp sulfakinins, while Hoa-SK II is a novel isoform. Exogenous application of either synthetic Hoa-SK I or Hoa-SK II to the isolated lobster heart increased both the frequency and amplitude of spontaneous heart contractions. In preparations in which spontaneous contractions were irregular, both peptides increased the regularity of the heartbeat. Our study provides the first molecular characterization of a sulfakinin-encoding cDNA from a crustacean, as well as the first demonstration of bioactivity for native sulfakinins in this group of arthropods.
Salinity-stimulated changes in expression and activity of two carbonic anhydrase isoforms in the blue crabCallinectes sapidus
Authors: Serrano Laetitia , Halanych Kenneth M. , Henry Raymond P.
Published: June 2007

Two isoforms of the enzyme carbonic anhydrase (CA) in the blue crab gill,CasCAg and CasCAc, were identified, sequenced, and found to match the membrane-associated and cytoplasmic isoforms, respectively. The membrane-associated isoform is present in much higher levels of mRNA expression in both anterior and posterior gills in crabs acclimated to high salinity (35 p.p.t.), but expression of the cytoplasmic isoform in the posterior gill undergoes a significantly greater degree of up-regulation after exposure to low salinity (15 p.p.t.). CasCAc has the largest scope of induction (100-fold) reported for any transport-related protein in the gill,and this may be necessary to overcome diffusion limitations between gill cytoplasm and the apical boundary layer. Furthermore, the timing of the changes in expression of CasCAc corresponds to the timing of the induction of protein-specific CA activity and CA protein concentration. No changes in CA mRNA expression or activity occur in the anterior gills. The pattern of up-regulation of expression of mRNA of the α-subunit of the Na+/K+-ATPase is similar to that for CasCAc, and both precede the establishment of the new acclimated physiological state of the crab in low salinity. A putative `housekeeping' gene, arginine kinase, also showed about a threefold increase in expression in response to low salinity,but only in the posterior gills. These results suggest that for studies of expression in crustacean gill tissue, a control tissue, such as the anterior gill, be used until an adequate control gene is identified.
Extreme anoxia tolerance in embryos of the annual killifishAustrofundulus limnaeus: insights from a metabolomics analysis
Authors: Podrabsky Jason E. , Lopez James P. , Fan Teresa W. M. , Higashi Richard , Somero George N.
Published: June 2007

The annual killifish Austrofundulus limnaeus survives in ephemeral pond habitats by producing drought-tolerant diapausing embryos. These embryos probably experience oxygen deprivation as part of their normal developmental environment. We assessed the anoxia tolerance of A. limnaeus embryos across the duration of embryonic development. Embryos develop a substantial tolerance to anoxia during early development, which peaks during diapause II. This extreme tolerance of anoxia is retained during the first 4 days of post-diapause II development and is then lost. Metabolism during anoxia appears to be supported mainly by production of lactate, with alanine and succinate production contributing to a lesser degree. Anoxic embryos also accumulate large quantities of γ-aminobutyrate (GABA), a potential protector of neural function. It appears that the suite of characters associated with normal development and entry into diapause II in this species prepares the embryos for long-term survival in anoxia even while the embryos are exposed to aerobic conditions. This is the first report of such extreme anoxia tolerance in a vertebrate embryo, and introduces a new model for the study of anoxia tolerance in vertebrates.
Effect of aerial O2 partial pressure on bimodal gas exchange and air-breathing behaviour inTrichogaster leeri
Authors: Alton Lesley A. , White Craig R. , Seymour Roger S.
Published: June 2007

The effects of experimental alterations of aerial O2 partial pressure (PO2,air) on bimodal gas exchange and air-breathing behaviour were investigated in the aquatic air-breathing fish Trichogaster leeri in normoxic water. Fish responded to increasing PO2,air by decreasing air-breathing frequency,increasing aerial O2 consumption rate(V̇O2), increasing mean O2 uptake per breath(V̇O2/breath) and decreasing aquatic V̇O2 to maintain a constant total V̇O2. The rate of oxygen uptake from the air-breathing organ (ABO) during apnoea(V̇O2,ap) was derived on a breath-by-breath basis from VO2/breath and apnoea duration. V̇O2,ap and estimates of ABO volume were used to calculate the PO2 in the ABO at the end of apnoea. This increased with increasing PO2,air, suggesting that ABO-PO2 is not regulated at a constant level by internal chemoreceptors. Furthermore, mean V̇O2,ap increased with increasing PO2,air, indicating that the observed increase in V̇O2/breath with increasing PO2,air was facilitated not only by an increase in apnoea duration but also by an increase in the air–blood PO2 gradient.
An investigation of the flow characteristics in the bootdeck region of a scale model notchback saloon vehicle
Authors: Lawson N J , Garry K P , Faucompret N
Published: June 2007

The results of an experimental investigation of the bootdeck flow structure of a 36 per cent scale model notchback car are presented together with a general review of advanced laser diagnostic techniques suitable for large-scale wind tunnel flow measurement. The tests were used to characterize the flow behaviour over the Reynolds number range 0.74 × 106-4.93 × 106 in the Cranfield University 2.4 m × 1.8 m wind tunnel. The experiments involved flow visualization, rear bootdeck and backlight three-dimensional stereoscopic particle image velocimetry (PIV) measurements, and mean static and unsteady static pressure measurements. Initial results from the flow visualization suggested flow asymmetries originating in the backlight region that were sensitive to the Reynolds number. The PIV data and static pressure data, however, showed little or no sensitivity of flow to Reynolds number with consistent flow structure and levels of unsteadiness from the backlight to the rear bootdeck region. At this stage no definitive reasons can be given for the discrepancies between the flow visualization and the other data, although the flow visualization data were particularly difficult to interpret near the backlight, and the near-wake structure may be bi-stable in this Reynolds number range. More detailed three-dimensional stereoscopic, time-resolved PIV flow data are now planned to quantify conclusively the correct flow structure and its sensitivities.
Spray density measurements using X-ray radiography
Authors: Kastengren A , Powell C F
Published: June 2007

An ultra-fast X-ray radiography technique has been developed to study the structure of diesel sprays. Radiography provides quantitative time-resolved measurements of the fuel distribution from near the spray orifice to the dispersed far-field spray. It offers several advantages over traditional spray diagnostics, since it provides quantitative data and is not limited to dilute regions of the spray. X-ray radiography does have significant limitations, however; the acquired data are ensemble averaged and pathlength integrated. The results which can be obtained from X-ray radiography are demonstrated using a short-duration (400 μs) low-pressure (250 bar) diesel injection into a gas at atmospheric pressure and room temperature from a Bosch light-duty diesel injector. Other possible uses of X-ray diagnostics and future directions in radiography research are also discussed.
Establishing combustion temperature in a hydrogen-fuelled engine using spectroscopic measurements
Authors: Ciatti S A , Bihari B , Wallner T
Published: June 2007

The results reported in this article are based upon spectrographic measurements taken form a single-cylinder hydrogen-powered internal combustion engine. The goals, as stated by the US Department of Energy, are for hydrogen engines to achieve 45 per cent peak brake thermal efficiency, 0.07 g/mile NO x emissions, and US $45/kW. One of the primary research interests in hydrogen engines is to ensure operation of the engine without requiring NO x after-treatment. A reliable method to measure combustion temperature will be useful to achieve this goal. However, unlike most hydrocarbon combustion systems that emit soot radiation, hydrogen combustion provides little in the way of measurable radiation emission except for the excited state of the hydroxyl radical (OH∗).

An optical fibre was inserted into the cylinder head of this engine to capture the photons emitted by the OH∗ radical during combustion. Based upon the distribution of the intensity of photons emitted in the 306–310 nm band, the temperature of the OH∗ radical can be calculated. A computer algorithm was used to simulate the energy distribution. This simulated distribution is then compared with the measured distribution, iterating the simulation by change of temperature until it appropriately matches the measured distribution. This diagnostic also has potential application to combustion systems that also do not emit soot radiation; advanced low-temperature combustion concepts such as homogeneous charge compression ignition.
Measurement and analysis of vibration and deformation using laser metrology for automotive application
Authors: Chen F , McKillip D
Published: June 2007

Vehicle quality has become one of the most important factors in customer satisfaction. Of all quality attributes, noise, vibration, and harshness (NVH) are often immediately noticed by customers during purchase trial drives or initial usage periods. High-quality NVH is, however, one of the most challenging attributes to achieve. Vehicle development constraints usually require that other attributes such as safety, durability, functionality, package, weight, and cost be satisfied prior to NVH attributes. Laser metrology has advantages including spatially dense data points and the fact that it is non-contact, non-invasive, and fast. It has become an indispensable tool to provide optimal solutions for achieving high-quality NVH under various constraints. This article focuses on the state of the art and its applications on reducing NVH and related concerns in the automotive industry.
Within-subject biological variation in disease: collated data and clinical consequences
Authors: Ricós Carmen , Iglesias Natalia , García-Lario José-Vicente , Simón Margarita , Cava Fernando , Hernández Amparo , Perich Carmen , Minchinela Joanna , Alvarez Virtudes , Doménech Maria-Vicenta , Jiménez Carlos-Victor , Biosca Carmen , Tena Raquel
Published: June 2007

Quantitative data on the components of biological variation (BV) are used for several purposes, including calculating the reference change value (RCV) required for the assessment of the significance of changes in serial results in an individual. Pathology may modify the set point in diseased patients and, more importantly, the variation around that set-point. Our aim was to collate all published BV data in situations other than health. We report the within-subject coefficient of variation (CVI) for 66 quantities in 34 disease states. We compared the results with the CVI determined in healthy individuals and examined whether the data derived in specific diseases could be useful for clinical applications. For the majority of quantities studied, CVI values are of the same order in disease and health: thus the use of RCV derived from healthy subjects for monitoring patients would be reasonable. However, for a small number of quantities considered to be disease specific markers, the CVI differed from those in health. This could mean that RCV derived from healthy CVI may be inappropriate for monitoring patients in certain diseases. Hence, disease-specific RCVs may be clinically useful.
Prevalence of increased serum creatine kinase activity due to macro-creatine kinase and experience of screening programmes in district general hospitals
Authors: Fahie-Wilson Michael N , Burrows Sally , Lawson Graham J , Gordon Tania , Wong Way , Dasgupta Bhaskar
Published: June 2007

Background: Macro creatine kinase type 1 (MCK1) may be the cause of elevated total serum CK activity, which can lead to diagnostic confusion. There is evidence that this problem is poorly recognized perhaps due to a lack of information on its prevalence. Precipitation with polyethylene glycol (PEG) has been described for the detection of MCK1 but has not been fully evaluated.

Methods: We introduced a screening programme to detect elevated serum total CK due to MCK1 and determine the prevalence of this problem using PEG precipitation with confirmation by gel filtration chromatography (GFC). The results were compared with those from a laboratory which selected samples for further investigation during the clinical validation process. We also studied characteristics of the PEG precipitation test including sensitivity and specificity when compared with GFC.

Results: Over 2 years we screened 368 patients. In 17 cases the proportion of CK activity precipitated by PEG was relatively high and the presence of MCK1 was confirmed in seven by GFC. In a second laboratory, over a period of 5 years, 11 samples were selected during the clinical validation process for further study and MCK1 was the cause of the elevated CK activity in six cases. PEG precipitates a proportion of normal, uncomplexed CK and this is increased by increasing serum globulin concentration and by higher concentrations of PEG.

Conclusions: The prevalence of elevated serum CK activity due to MCK1 was approximately 2%. Laboratories should consider introducing a systematic screening programme based on PEG precipitation.
Profound hypocalcaemia associated with bilateral cataracts post-total thyroidectomy
Authors: Freedman Danielle B , Smith Natalie , Housley David
Published: June 2007

Profound hypocalcaemia is an uncommon presentation from primary care. We describe a case of hypocalcaemia presenting 4 years after total thyroidectomy. Long-term complications of chronic hypocalcaemia are rarely seen in clinical practice today, but had occurred in this case with the development of bilateral cataracts. All patients should be monitored following thyroidectomy to ensure that hypocalcaemia does not persist. In addition to this, patients with a history of thyroid surgery presenting with cataracts should have serum calcium measured.
Stability of creatinine with delayed separation of whole blood and implications for eGFR
Authors: Shepherd J , Warner M H , Kilpatrick E S
Published: June 2007

Background: The stability of creatinine in whole blood is unclear: it is not known if analysis of creatinine in samples with delayed separation could lead to misclassification of chronic kidney disease (CKD) using estimated glomerular filtration rate (eGFR).

Methods: Multiple blood samples were taken at a single time-point from five individuals and subject to varying time delays prior to centrifugation, after which serum was separated and analysed for creatinine by five different methods. The effect of time delay on eGFR was further investigated by measuring creatinine on duplicate patient samples arriving in the laboratory after immediate and delayed centrifugation.

Results: A significant increase in creatinine was seen by 24 h using kinetic Jaffe methods ( P<0.025). Over a period of 31 h creatinine concentration was stable using enzymatic creatinine assays. Using duplicate patient samples, four of 21 patients where specimens were delayed in the laboratory by more than 10 h showed a misclassification of CKD.

Conclusion: Delays in sample receipt can lead to significant increases in measured creatinine and misclassification of CKD. Enzymatic creatinine assays are reliable with respect to delayed sample receipt over the time course studied.
Latent autoimmune diabetes in adults: increased awareness will aid diagnosis
Authors: Fielding Andrew M , Brophy Sinead , Davies Helen , Williams Rhys
Published: June 2007

Latent autoimmune diabetes iln adults (LADA) is the term used for patients with non-insulin dependent diabetes who progress to insulin dependency as their pancreatic secretion of insulin fails. Diagnosis is based on adult age at the time of diabetes, the presence of serum autoantibodies to pancreatic antigens and the absence of a requirement for insulin at diagnosis. High titres of serum glutamic acid decarboxylase (GAD) antibodies act as a marker for LADA. Serum C-peptide concentrations are also lower in autoimmune diabetic patients. The best treatment for patients with LADA is not clear, but early insulin treatment may prevent pancreatic β-cell failure.
Extended storage of whole blood with 3-deazaadenosine for homocysteine assay
Authors: Hansrani Monica , Stansby Gerard
Published: June 2007

Background: To assess the effectiveness of using 3-deazaadenosine (3DAA) to maintain plasma homocysteine concentrations (tHCy) in whole blood samples.

Methods: Blood was obtained from five volunteers and samples were maintained at room temperature, in cold packs or in a fridge (0-4°C) with and without 3DAA. At time points ranging from 6 to 168 h, samples were processed and analysed for tHCy using the Abbott IMx system.

Results: There was a mean increase in tHCy of 29.4% at 6 h increasing to 242.6% after 168 h in whole blood kept at room temperature. There was no significant change in tHCy for 48 h when stored in cold packs, and for 72 h when stored in the fridge. The addition of 3DAA had a significant preservative effect ( P<0.001), maintaining tHCy to 48 h in whole blood at room temperature, 120 h in the fridge and 96 h in cool packs. There was no statistical difference in results obtained from samples containing preservative and controls when using the Abbott IMx system.

Conclusion: 3DAA is an effective preservative of tHCy in whole blood, particularly in samples maintained at 0-4°C.
Nitric oxide accelerates the degradation of tetrahydrobiopterin but not total neopterin in cerebrospinal fluid; potential implications for the assessment of tetrahydrobiopterin metabolism
Authors: Lam A A J , Heales S J R
Published: June 2007

Assessment of total neopterin and tetrahydrobioterin (BH4) concentrations in cerebrospinal fluid (CSF) can be used to identify potential disorders of BH4 biosynthesis. In this study, we demonstrate that exposure of CSF to nitric oxide leads to an accelerated degradation of BH4 but does not affect the total neopterin concentration. These data suggest that in those conditions associated with increased nitric oxide formation, perturbation of the total neopterin to BH4 ratio could occur. Under such circumstances a putative diagnosis of a defect in BH4 biosynthesis may erroneously be proposed. Assessment of central nitric oxide generation may therefore be a useful adjunct to the determination of CSF pterin status.
Cardiac troponin I concentrations in people presenting with diabetic ketoacidosis
Authors: Geddes J , Deans K A , Cormack A , Motherwell D , Paterson K , O'Reilly D St J , Fisher B M
Published: June 2007

Background: Elevated troponin concentrations may be observed in a wide spectrum of medical disorders in people without evidence of overt ischaemic heart disease. The prospective relationship between serum cardiac troponin I (cTnI) and diabetic ketoacidosis (DKA) has not been examined in adults.

Methods: Forty patients (14 male and 26 female) with type 1 diabetes were recruited. cTnI, creatine kinase (CK), cystatin C and beta-hydroxybutyrate were measured on admission and at 24, 48 and 72 h post-admission. Daily electrocardiographs were also performed.

Results: Four out of forty subjects presenting with DKA had an increase in cTnI (median (SD) 0.06 (0.31) μg/L). One of the subjects had multiple possible reasons for the elevated cTnI concentration. However, the other three subjects had no obvious precipitating factors. This cohort underwent echocardiography and thallium-201 scintigraphy, which revealed no abnormalities.

Conclusions: Minor troponin elevations appear to occur in a small number of subjects with type 1 diabetes presenting with DKA. The clinical relevance of this at this stage remains unknown and further large-scale studies are suggested.
Serum remnant lipoprotein cholesterol/triglyceride ratio as an index for screening familial type III hyperlipidaemia
Authors: Nakajima Katsuyuki , Daimon Masahiro , Kamiyama Kiyoshi , Takanashi Kunihiko , Suzuki Yukiko , Watanabe Masakazu , Kubono Katsuo , Saniabadi Abby R , Takashima Sei-Ichi , Sakurabayashi Ikunosuke
Published: June 2007

Background: An elevated serum remnant lipoprotein cholesterol (RLP-C)/triglyceride (TG) ratio has not been evaluated as an index of familial type III hyperlipidaemia defined by the presence of β-VLDL and apolipoprotein (Apo) E2/2 phenotype in the Japanese hyperlipidaemic population.

Methods: Serum lipids and lipoproteins from 514 individuals (200 men and 314 women, mean age 58 years) with total cholesterol >6.22 mmol/L and TG between 2.26 mmol/L and 9.04 mmol/L, selected from 25,080 subjects visiting the clinics for health checkup were analysed for a possible relationship with familial type III hyperlipoproteinaemia.

Results: Median RLP-C concentration and RLP-C/TG ratio were 0.30 and 0.11 mmol/L, respectively. When compared between subjects with (31 cases) and without (483 cases) a broad-beta band on electrophoresis, the RLP-C concentrations and RLP-C/TG ratio were 0.77±0.43 mmol/L versus 0.34±0.16 mmol/L ( P<0.0001) and 0.15±0.023 versus 0.11±0.027 ( P<0.0001), respectively. Three cases with broad-beta band positive (the presence of β-VLDL) showed RLP-C/TG ratio greater than 0.23 and RLP-C greater than 0.78 mmol/L, suggestive of type III hyperlipoproteinaemia, despite a lack of characteristic Apo E2/2 homozygosity. Cases with Apo E/Apo CIII ratio greater than 1.0 were not detected in this study group.

Conclusion: Serum RLP-C concentration and RLP-C/TG ratio, together with Apo E/Apo CIII ratio appear to be useful for screening familial type III hyperlipidaemia in the Japanese hyperlipidaemic population.
Validity of simplified protocols to estimate glomerular filtration rate using iohexol clearance
Authors: James T J , Lewis A V , Tan G D , Altmann P , Taylor R P , Levy J C
Published: June 2007

Background: Iohexol clearance is an accurate and precise exogenous marker of glomerular filtration rate (GFR), but protocols are generally lengthy or require multiple sampling. Shorter or simpler protocols would be more practicable.

Methods: Two clearance estimates, two weeks apart, were undertaken in 11 healthy individuals and 26 diabetic patients with minimal to moderate renal impairment (chronic kidney disease stages 1-3). Blood specimens withdrawn at 60, 90, 120, 150, 180 and 240 min post-iohexol were analysed for iohexol.

Results: Visit 1 demonstrated excellent correlation with visit 2 (slope 1.00, confidence interval [CI] 0.88 to 1.13, intercept 0.94 mL/min/1.73 m2, CI -9.9 to 11.8, P=0.43). The within-individual coefficient of variation (CV) of the 240 min reference method was 5.4% at a mean GFR of 84.1 mL/min/1.73 m2. Single point estimates between 120 and 240 min had CVs of 4.5-7.0%, and did not differ from the reference method CV by more than 2.0 mL/min/1.73 m2. Two and three point estimates in the interval 60-120 min post iohexol injection offered no advantages over these single-point estimates and overestimated at lower GFRs.

Conclusions: An iohexol clearance estimate of GFR derived from a single sample taken between 2 to 4 h after infusion may provide a suitable tool for routine clinical use.
Tumour regression and relapse in mice inoculated with murine sarcoma virus (Moloney)
Authors: Perk K. , Russell E. , Smith K. L. , Moloney J. B.
Published: June 2007

The oncogenic effect of the virus was tested in mice of different strains and ages. Local sarcomas were induced in all mice, although strain, age or dose dependent variations were found. 4 forms of development occurred: progressive lethal; lethal but long persistent; complete tumour regression; tumour recurrence after regression. Virus activity was highest in the progressively-growing and in the recurrent tumours, while in the long-persistent tumours or in tissue at the site of regressed tumours, little or no virus could be detected.
Techniques for rearing gnotobiotic lambs
Authors: Alexander T. J. L. , Lysons R. J. , Elliott Linda M. , Wellstead Patricia D.
Published: June 2007

Techniques are described for rearing, sampling and studying gnotobiotic lambs up to 5 months of age.
Alopecia in rats housed in groups
Authors: Beare-Rogers Joyce L. , McGowan J. E.
Published: June 2007

Young male rats fed experimental diets containing 20% by weight of fat developed alopecia when housed in groups, but not in individual cages.
Hydronephrosis in inbred strains of mice with particular reference to the BRVR strain
Authors: Taylor D. M. , Fraser H.
Published: June 2007

Hydronephrosis occurred in 6 of the 13 inbred mouse strains maintained in the same colony. Its incidence was high only in the BRVR strain, where about half of the cases could only be detected microscopically. There was no concomitant infection even in severely abnormal BRVR kidneys and the incidence of the condition was not influenced by dietary variation. The hydronephrosis found, less frequently, in 5 of the other strains was of a different type from that in BRVR mice.
The effect of the number of animals per cage on the growth of the rat
Authors: Hughes P. C. R. , Nowak M.
Published: June 2007

Animals were bred and reared normally, but at weaning were distributed either singly, in pairs, or 4 to a cage. Measurements of length and weight were made during the growth period. In females there were no differences between the caging regimes, but males kept 4 to a cage were significantly smaller than those kept 2 to a cage or singly.
Changes in aortic medial elastic structure at different sites in the primates Erythrocebus patas, Macaca irus and Callithrix jacchus
Authors: Berry C. L. , Germain Jocelyn
Published: June 2007

There is a progressive reduction in the number of lamellar units in the aortic media in these primates as the distance from the aortic root increases. The structure of the media is similar in many primates and this suggests that they may prove suitable animals in which to study mechanical aspects of atherogenesis.
Drug-induced lenticular lesions in the rat
Authors: Heywood R.
Published: June 2007

Drug-induced cataract in the rat can be classified into 2 main types: acute reversible opacities and permanent cataracts. The permanent cataracts are initiated either at the equator or the poles of the lens. It is suggested that acute and chronic forms of drug-induced toxic effects on the lens are expressed by these changes.
Genetic monitoring of laboratory mouse colonies in the medical research council accreditation scheme for the suppliers of laboratory animals
Authors: Festing Michael F.
Published: June 2007

A method of analysing mandible samples using 4 discriminant functions to describe mandible shape, and plotting the samples on control charts, as used in industrial quality control, is described. Repeated samples from 3 different colonies gave consistent results, with only occasional samples 'out of control'. 5 known 'illegitimate' samples were correctly rejected, and 3 out of 4 'legitimate' samples were accepted as belonging to stock LACA. In the 4th case lack of fit was attributed to subline-differentiation. This method of genetic analysis is practical for the large-scale genetic monitoring of laboratory mouse strains and stocks, and a Genetic Monitoring Scheme is being offered to commercial breeders.
Soft faeces excretion and passage time in the laboratory rabbit
Authors: Jilge B.
Published: June 2007

Adult male rabbits, wearing a plastic collar to prevent coprophagy, excreted soft faeces during the first half of the light phase, starting at about the time the light switched on at 0600. While soft faeces were being excreted, food intake was reduced considerably in collared as well as in non-collared animals.

Rate of passage of gastrointestinal contents in the rabbit was extremely high. Chromic oxide appeared in the faeces 4-5 h after it had been ingested in pelleted food. Coprophagy had no effect upon the rate of passage of gastrointestinal contents, and chromic oxide passed through at the same rate, whether it was incorporated in soft faeces or in pelleted diet.
A growth model for laboratory rats
Authors: Brunden M. N. , W.Clapp H. , Heun L. L.
Published: June 2007

Our rats are generally requisitioned by bodyweight. It is imperative, therefore, that an efficient method be used for determining the weights of animals in a given location to fill order commitments. Given any beginning average weight at an age on or after 21 days this method predicts the average weight of animals in a cage for any future date within practical limits. It assumes that the growth curve may be adequately represented by linear segments. The method also accounts for the differing growth rates of light and heavy animals. In order to maintain current estimates of these growth rates, we take a small weekly sample of representative rats at 21 days of age. These animals are reweighed weekly to provide data for continual reestimation of the growth-rate parameters used for prediction.
Hepatitis and brain lesions due to mouse hepatitis virus accompanied by wasting in nude mice
Authors: Sebesteny A. , Hill A. C.
Published: June 2007

Severe necrotising hepatitis, with microscopic brain lesions containing multi-nucleated giant cells, was observed in specified-pathogen-free nu-nu mice, contained in a semi-protected environment, but within the same room as other, conventional, mice. An entire group of 40 nu-nu mice died within a month, with no evidence of bacterial or parasitic infection. However, cell-free liver filtrates reproduced the liver lesions in specified-pathogen-free Swiss-Schneider mice injected intraperitoneally at up to 21 days of age, but not in baby rats and hamsters.

Electronmicroscopy showed masses of particles resembling mouse hepatitis virus in the liver lesions of the recipient mice, and the identity of the virus was further confirmed serologically and by its physical properties. It was concluded that the infection was caused by a neurotropic variant of mouse hepatitis virus and could have originated from the conventional mice kept in the same room.
A water-maze test of learning ability for guinea-pigs
Authors: Smart J. L. , Adlard B. P. F.
Published: June 2007

A test of learning ability for guinea-pigs is described. A T-shaped water maze was used, in which the animals were required to swim into one or the other of the arms to escape from the water. In this situation guinea-pigs readily learned a spatial discrimination and its reversal. They continued to thrive during the period of testing.
The transmission of intestinal flagellates between mice and rats
Authors: Sebesteny A.
Published: June 2007

Following an outbreak in rats in an experimental holding unit of Hexamita and Giardia infestation of evidently murine origin, these flagellates were successfully transmitted experimentally from mice to rats, and from these rats to mice again.
Sex factors in airborne infection: comparative susceptibility of male and female non-immunized mice to aerosolized Pasteurella multocida
Authors: Bouley G. , Dubreuil A. , Prulière D. , Bouley M.
Published: June 2007

351 SPF OF1 non-immunized mice of both sexes were infected by aerosolized Pasteurella multocida. Female mice were significantly less susceptible to infection than were males of the same age (which were heavier). Males and females of equal bodyweight, but different age, showed no significant difference in susceptibility.

The difference at equal ages can be explained by the lower respiratory flow of females. The consequences of these results for experimental studies on atmospheric pollutants are discussed.
Zinc deficiency in female rabbits
Authors: Shaw Nancy A. , Dickey H. C. , Brugman H. H. , Blamberg D. L. , Witter J. F.
Published: June 2007

Zinc deficiency was induced in recently weaned female Tan rabbits by feeding a diet containing 0·2 p.p.m. of zinc and severely limiting their access to zinc from other sources in the environment. Reduced food consumption, weight loss, lowered haematocrit levels, frequent appearance of alopecia and dermatosis as well as reproductive failure were observed. Histologically, the uteri of the zinc-deficient rabbits were pale and inactive. The ovaries had Graafian follicles but lacked corpora lutea despite repeated attempts to mate the females.
Spontaneous epizootic of pneumococcus infection in guinea-pigs
Authors: Keyhani Massoud , Naghshineh Reza
Published: June 2007

Type 19 Diplococcus pneumoniae was identified as the organism responsible for an outbreak of pneumonia.
Brain and spinal cord lesions in the newborn rat
Authors: Curless Richard G. , Nelson Marilyn B. , Brimmer Francis , Tellez Cisco
Published: June 2007

Previous studies involving the induction of central nervous system lesions in animals have required complex, expensive equipment including stereotaxis and an operating microscope. This study describes a technique for producing telencephalic (forebrain) lesions in the developing rat by the use of copper wire. In addition, a nonvisual method of producing spinal cord transections in the young rat is discussed. Both techniques have a high success rate and minimal mortality.
A method for mechanised staining of rat and mouse foetuses for teratological examination
Authors: Tipton P. W. , Burt Marilyn E.
Published: June 2007

The staining method uses alizarin red S and has been adapted for a 4-5 day cycle on a standard tissue processor. It gives consistently well stained bones and clear soft tissues in both rats and mice.
Inhibition of bacteria in mouse drinking water by chlorination
Authors: Bywater J. E. C. , Kellett B. S.
Published: June 2007

Experience with the use of mouse drinking water containing chlorine is discussed. With an initial concentration of 5 p.p.m. bacteria were recovered from the bottles after 7 days and there was considerable growth in untreated bottles. Above this concentration no bacteria survived. It is recommended that 15-20 p.p.m. chlorine are used for practical purposes.
The use of biotyping of Enterobacteriaceae as an evaluation of the isolation efficacy of laboratory animals
Authors: Harleman J. H. , Koopman J. P. , Bremer-Mulder W. G. M.
Published: June 2007

2 sets of data are given of biotyping the Enterobacteriaceae from the faecal flora of SPF rats and cats housed with different isolation arrangements. The method is presented as an evaluation of the isolation efficiency of laboratory animals. Biotypes which were determined on almost every occasion belonged to the resident flora of the animals while those found occasionally represented contamination. Contaminating bacteria are cleared from an SPF breeding unit by colonization resistance and the continuous efflux of animals from the unit. A parameter of isolation efficacy is the number of different biotypes determined in time. With optimal isolation arrangements a stable bacterial flora of permanently colonized biotypes is obtained in the animals.
Staphylococcal kidney abscesses in rats treated with corticosteroids
Authors: Simmons D. J. C. , Simpson W.
Published: June 2007

A heavy growth of Staphylococcus aureus was isolated from kidney abscesses in rats from 2 inbred strains treated with corticosteroids. The S. aureus phage types which caused the abscesses are endemic in the rat breeding colonies. One strain of rat was more sensitive to the action of the corticosteroids.
Abnormal urogenital organs occurring spontaneously in inbred ACI and Kyoto-notched rats
Authors: Shoji Ryujiro , Harata Masayo
Published: June 2007

Spontaneous malformations of urogenital organs found in inbred rat foetuses of ACI/NHok strain were further investigated with a postnatal survey involving other inbred strains. A new type of malformation occurred in Kyoto-notched rats. The present findings suggested that the malformations have different hereditary characteristics caused by different maldevelopmental mechanisms and are probably due to recessive polygenes.
Isolation of Encephalitozoon cuniculi from urine samples
Authors: Pye D. , Cox J. C.
Published: June 2007

Encephalitozoon cuniculi was isolated from the urine of infected rabbits using human and canine tissue cultures. The organism was isolated from 7 of 11 contaminated urines from seropositive animals. The advantages of urine over tissue as a source of E. cuniculi are that it is obtainable from living animals, can be examined for the presence of organisms, and is essentially free of cells likely to overgrow the tissue cultures used for isolation.
Identification and genetic monitoring of mouse inbred strains using biochemical polymorphisms
Authors: Groen A.
Published: June 2007

53 inbred strains and substrains of mice from 3 institutes in The Netherlands were examined at 12 chromosome loci coding body protein-polymorphism (Es-1, Es-2, Es-3, Es-S, Gpi-1, Hbb, Id-1, Ldr-1, Mpi-1, Mup-1, pgm-1, Trf). The allelic variation at 7 loci could be detected simultaneously.

Within each institute most strains showed a unique combination of alleles at the 12 loci involved. Some nominally similar (sub)strains showed allelic divergence. One strain showed allelic variation at 4 loci. These findings emphasize the possibility and the necessity of monitoring the genetic purity of inbred strains of mice. A routine monitoring scheme using body protein-polymorphisms is proposed.
Sexing mouse pups
Authors: Greenham Leighton W. , Greenham Valerie
Published: June 2007

Data on the early sexing of random-bred albino mice ( Mus musculus) is presented. It is shown that accurate sexing of newborn pups cannot be made by anogenital distance measurement unless the proportion of animals falling into the overlap-zones are discarded. However, 8-day-old pups may be sexed by the display of abdominal (inguinal) teats in the females.
Seasonal variation in litter size, bodyweight and sexual maturation in juvenile female house mice (Mus musculus)
Authors: Drickamer Lee C.
Published: June 2007

Over a 4-year period a higher proportion of mated females bore litters during spring and summer than in late autumn and winter. Litter sizes were larger and young female mice weighed more at 21 days of age during spring and summer than at other times. However, young females attained sexual maturity, as indicated by vaginal smears, earlier during the winter months. This contrasts with data indicating that pubertal female mice have lower uterine weights in winter. A multiple regression analysis revealed that mouse bodyweights at 35 days of age and at 1st oestrus were important variables for predicting the age of puberty. Possible factors influencing reproductive seasonality in female house mice maintained under laboratory conditions are discussed.
The microbiology of a new recirculatory automatic watering system compared with a conventional automatic system
Authors: Taylor K. , Franklin G. , Shaw C. M.
Published: June 2007

Continual recirculation and filtration of drinking water prevents the contamination that often mars automatic watering systems by removing algae and fluorescent pseudomonads. Without filtration and recirculation, the algae were clearly visible after 40 days use, and the fluorescent pseudomonad count rose from 101 to 105 per ml after 72 h use.
A new form of automatic watering system for laboratory animals
Authors: Taylor K. , Pope R.
Published: June 2007

During a 2½ year trial of this new system no algal or bacterial build-up occurred, and filters were changed only at infrequent intervals. Among the labour-saving advantages of it is that cleaning of the system can be done when cage racks are changed, normally monthly.
Water-borne Bacillus licheniformis infection in mice
Authors: Wright D. J. M. , Frost D. J. , Eaton P.
Published: June 2007

A water-borne Bacillus licheniformis infection was associated with depressed haemoglobin content, white cell and platelet count. The epidemic was resolved by changing from tanked to mains water supply.
The occurrence in mice of facial and mandibular abscesses associated with Staphylococcus aureus
Authors: Clarke M. C. , Taylor R. J. , Hall G. A. , Jones P. W.
Published: June 2007

Swellings affecting the face and jaws of a strain of outbred BSVS mice are described. The swellings consisted of multiple abscesses which were most commonly associated with the mandible. Staphylococcus aureus of a single phage type was isolated from the abscesses. It is suggested that the organisms gained entry through the oral mucosa.
Provocation of pseudomoniasis with cyclophosphamide in mice
Authors: Urano T. , Maejima K.
Published: June 2007

After treatment with cyclophosphamide, a fatal syndrome was found in mice contaminated with Pseudomonas aeruginosa. The syndrome seems to be caused by P. aeruginosa from the intestine, and the liver is suspected to be the most important target organ.
Some Aspects of the Physiology and Anatomy of the Cardiovascular System of the Ferret, Mustela Putorius Furo
Authors: Andrews P. L. R. , Bower A. J. , Illman O.
Published: June 2007

Summary

The resting heart rate was monitored in SO urethane-anaesthetized (387 ± 54 beats/min) and 4 conscious (341 ± 39 beats/min) ferrets. The arterial blood pressure in the anaesthetized animals was 140/110 ± 35/31 mmHg. The circulatory responses to vagal stimulation, carotid artery occlusion and a variety of humoral agents were examined. The vagal innervation of the heart and of the distribution of the great vessels are described.
Transmission of Spironucleus and Giardia Spp. and Some Nonpathogenic Intestinal Protozoa from Infested Hamsters to Mice
Authors: Sebesteny A.
Published: June 2007

Summary

Intestinal protozoa belonging to the genera Spironucleus (Hexamita), Giardia, Trichomonas and Entamoeba, carried by conventional hamsters, were successfully transmitted to and established in protozoa-free sucking or newly-weaned specified-pathogen-free inbred mice by exposure of the mice to hamster intestinal contents.