bluuebunny/crossref_metadata_2025 huggingface dataset:
Strain-energy bounds in finite-element analysis by slab analogy
Authors: De Veubeke B Fraeijs , Zienkiewicz O C
Published: June 2007

It is well known that in approximate analysis of elasticity problems lower and upper bounds to the true strain-energy content can be obtained by the alternative assumptions of compatible displacement fields or of equilibrating stress fields. While formulations based on the first are relatively easy to achieve those based on the second present many difficulties. In this paper it is shown how by virtue of the analogy between plane-elasticity and slab-deflection problems compatible-displacement formulations in either one can be used to generate equilibrating formulations in the other. This should result in a direct application of existing programmes to a wider range of problems.
Failure of glass-reinforced plastics under single and repeated loading
Authors: Owen M J , Dukes R
Published: June 2007

A review of some failure mechanisms of glass-reinforced plastics under single and repeated (fatigue) loading is presented. Published work of both an experimental and an analytical nature is included. There are several micrographs and a brief description of the component materials is given.
Pressure stresses at discrete supports on spherical shells
Authors: Kitching R , Olsen B
Published: June 2007

The discontinuity stresses in the vicinity of discrete supports welded to the hemispherical end of a pressure vessel under internal pressure have been measured. Four brackets fabricated from flat plates and three tubular supports were examined. Experimental stresses compared reasonably well with stresses estimated by approximate analytical methods which are suggested as standard design checks.
Reinforcement of non-central holes in rotating discs
Authors: Fessler H , Thorpe T E
Published: June 2007

The frozen-stress photoelastic technique was used to determine the stresses around reinforced non-central holes in discs. Both circular bosses and a thickened annulus were used as reinforcements. Calculations by Green, Hooper, and Hetherington were found to predict the mean stresses (through the thickness) well but these calculations cannot predict the peak stresses. The latter were not significantly less than the values of the unreinforced perforated discs. The stresses in a taper disc were lower than in a disc of constant thickness.
A method of convergence for finite difference thermal stress computation in axially symmetrical bodies
Authors: Chow C L , Hoyle R
Published: June 2007

The most general axially symmetrical thermal load is one in which a transient temperature distribution, varying axially and radially, is applied to an axially symmetrical system with an irregular axial boundary. When the thermal stress equations are applied to such a system, using the conventional Gauss-Siedel or Liebmann method, severe oscillation has been experienced making convergence impossible to achieve. The authors present in this paper a method which not only converts a diverging solution but also yields a rapid rate of convergence. This method has been successfully applied to the problem of a steam turbine rotor.
Criteria of failure for a cantilever subjected to repeated shock loading
Authors: Srinivasan P , Rau I S
Published: June 2007

The results of a theoretical and experimental invetigation to determine the fatigue life of a cantilever (with tip mass) subjected to repeated shock loading of the half-sine-wave form are presented. From a simple law of fatigue-crack propagation cumulative damage criteria for predicting fatigue life under variable-amplitude loading are developed. The unknown constants in these criteria are determined from conventional constant-amplitude fatigue tests on a repeated-bending testing machine. From the response of the shock-excited structure determined from linear single-degree-of-freedom theory and the cumulative damage criteria developed, relations for predicting fatigue life under repeated shock loading are developed. The theoretical predictions are then compared with the experimental dau obtained by actually conducting the repeated shock test on a specially designed shock testing machine. The agreement between theory and experiment is fairly good for steel, the material for which the test results are reported.
Anaesthesia of germ-free rabbits and rats with halothane
Authors: Cook R. , Dorman R. G.
Published: June 2007

A simple and effective method for anaesthetising germ-free rabbits and rats for the collection of heart-blood samples is described. The anaesthetic agent, a mixture of 2 or 4 per cent halothane in oxygen, was passed into the germ-free isolators through a tube sealed into the wall and fitted at each end with a high-efficiency gas line filter.
Studies on murine lymphocytic choriomeningitis within a partially infected colony
Authors: Skinner H. H. , Knight E. H.
Published: June 2007

Monitoring for lymphocytic choriomeningitis (LCM) infections was maintained for 10 months on the first generations (123 litters) of a mouse colony of 16 pairs composed of 4 groups with each of the following combinations of LCM-free (SPF) and LCM congenitally infected (PTI) mice-SPF ♂ x SPF ♀, PTI ♂ x PTI ♀, SPF ♂ x PTI ♀, PTI ♂ x SPF ♀. The PTI mice were from a conventional colony recently found to be infected in some of its sections with LCM virus from an unknown source.

The studies confirmed that the epidemiological characteristics of this new virus strain were identical with those first noted by Traub in 1938.

Progeny of the PTI females had a persistent tolerant infection. The progeny of the PTI ♂ x SPF ♀ pairs, though born without infection, thereafter often acquired tolerant or non-tolerant infections through contact with the PTI male parent. Progeny of the SPF x SPF pairs remained LCM-free throughout the period despite the high infectivity of the excretions from the neighbouring PTI mice. This confirmed the feasibility of eradicating this latent infection from a mouse colony containing a proportion of LCM-free mice.
A method of assessment of central nervous function in mice with viral encephalomyelitis
Authors: Seamer John , Peto S.
Published: June 2007

A quantitative investigation into the balancing and locomotor function, learning and memory of mice infected with an arthropod-borne virus is described. Mice can remain on a rod rotating in a horizontal plane about its long axis, and this natural ability can be assessed by counting the number of times they fall off. The mice improve their ability with experience and can retain the improved ability for short periods. Natural ability in mice about 25 days old was greater than in those 3 weeks older. This ability was diminished by the encephalomyelitis which resulted from infection with Langat virus.

Within the limits of the experiments the rate of learning depended upon the number of trials rather than the interval between them. Memory lasting 10 days or longer was demonstrated in some mice but evidence on the effect of ageing on learning and memory was conflicting. Despite the presence of Langat virus infection the learning ability and memory of mice which showed no clinical signs of disease appeared to be unimpaired.
Cystic adenocarcinoma of the ascending colon in rats occurring as a self-limiting outbreak
Authors: Heslop Barbara F.
Published: June 2007

A series of 44 cases of cystic adenocarcinoma of the ascending colon is described in a strain of inbred albino rats. The disease occurred as a self-limiting outbreak over a 14-month period, the distribution of cases suggesting an infective aetiology.
Effects of daily handling and other factors on weight gain of mice from birth to six weeks of age
Authors: Porter G. , Festing M.
Published: June 2007

The results of this experiment show that growth rate in mice is so sensitive to environmental factors that any change in the environment such as handling or diet could cause short-term changes in the rate of growth. It is also shown that if there is a period of restricted growth due to an environmental factor such as either handling or diet, this may be followed by a period of compensating rapid growth.
Pathogenicity of intestinal flagellates in mice
Authors: Sebesteny A.
Published: June 2007

The results of the clinical investigation and control of a murine condition associated with heavy Hexamita muris infestation of the small intestine revealed its similarity to murine giardiasis, and suggested a possible pathogenic role of Hexamita muris in mice.
Effects of gamma-irradiation on the vitamin content of diets for laboratory animals
Authors: Coates Marie E. , Ford J. E. , Gregory Margaret E. , Thompson S. Y.
Published: June 2007

Practical-type diets for chicks, guinea-pigs and cats, and a chick diet of purified ingredients, were assayed for their vitamin content before and after gamma-irradiation at doses ranging from 2 to 5 Mrad.

Irradiation of guinea-pig and chick diets resulted in small losses of vitamin A (in this investigation, 6 and 12 per cent respectively). Losses of vitamin E were larger (24 and 65 per cent) but were much less (11 per cent) when the diets were vacuum-packed before irradiation.

Vitamins were less stable in the purified chick diets, the most susceptible being vitamins A, E, B6 and thiamine. Vitamin destruction was greatly increased when antioxidants were incorporated into this diet, and also when its moisture content was high.

Vitamin A and β-carotene were almost completely destroyed in the cat diet, where there was also some loss of thiamine and folic acid.
A safe method of handling rhesus monkeys (Macaca mulatta)
Authors: Melvin Jennifer M. O. , Beck J. Swanson
Published: June 2007

A simple handling box for rhesus monkeys is described. It is easy to use and there is minimal contact between handler and monkey, thereby ensuring greater safety for personnel working with these animals than is found with other methods of handling. For minor procedures there is no need to sedate monkeys restrained in the box.

The box can easily be adapted for use with other primate species and for the performance of a wide variety of experimental techniques.
Effect of supplementing a commercial diet with vitamin K3 for males of two strains of rats
Authors: Frape D. L. , Wilkinson J. , Chubb L. G.
Published: June 2007

The dietary need for supplementary vitamin K3 (sodium menaphthone bisulphite) was determined in weanling male rats of two hysterectomy-derived strains fed on Spillers Laboratory Small Animal Diet (autoclaved). The basal diet had 0.6 ppm of added vitamin K3 to which further supplements of either 0, 4, 16 or 64 ppm vitamin K3 were added. There was a significant difference between strains in body-weight gain (P<0.001) but not in plasma prothrombin time. After 14 weeks the mean plasma prothrombin time of rats receiving the basal diet was higher (P<0.01) than the mean of those receiving the supplemented diets; but the three supplemented diets did not differ significantly.
Daily patterns of feeding and excretion in rats confined to metabolism cages : strain and age differences
Authors: Bellamy D. , Lamming P. A. , Stevenson A.
Published: June 2007

Data are presented on the daily feeding and excretion patterns of Wistar, Sprague-Dawley and Wistar/Sprague-Dawley hybrid rats confined to metabolism cages.

All strains were characterized by the formation of a grossly hypertonic urine which contained high concentrations of both sodium and potassium. Daily concentration rhythms were found in urinary sodium, potassium, calcium and magnesium, but the magnitude of these rhythms depended on strain and age.

Rats of all ages were characterized by a high turnover of water and salts. A large proportion of the water was lost by routes other than urine and faeces, and the animals appeared to absorb a slightly hypertonic salt solution from the intestine (the result of eating and drinking) in order to counteract this water loss.
Breeding the stump-tailed macaque, Macaca arctoides
Authors: Trollope J. , Blurton-Jones N. G.
Published: June 2007

The establishment of a small breeding colony of Macaca arctoides is described and compared with reports on breeding Macaca mulatta.

Despite restrictions imposed on the breeding methods by a developmental ethological study, 7 young, 6 of which were conceived in the laboratory, have been obtained from 6 females in just over 3 years.
A comparison between irradiated and autoclaved diets for breeding mice, with observations on palatability
Authors: Porter G. , Festing M.
Published: June 2007

Two commercial laboratory mouse diets were sterilized by either high-vacuum autoclaving or gamma irradiation, and then fed to breeding mice of 2 different strains housed as monogamous pairs or trios.

There was a statistically significant diet-by-sterilization-method interaction for total number of mice weaned, although neither the effect of 'diet' nor 'sterilization method' were statistically significant. Thus with diet FFG an average of 45.1 young was weaned per cage on irradiated diet compared with 55.6 on the autoclaved diet, while 51.4 mice were weaned per cage on irradiated Breeding Diet compared with 47.6 on the autoc1aved. This result suggests that the effects of sterilization by either method depend on the nature of the diet, so that it should be possible to design diets capable of being sterilized by autoclaving or irradiation.

Palatability trials indicated a strong preference for irradiated diet over autoclaved diet.
The breeding, care and management of vespertilionid bats in the laboratory
Authors: Racey P. A.
Published: June 2007

The caging, feeding and general husbandry of 5 species of British vespertilionid bats is described. They are maintained in the laboratory for studies of their reproductive biology, and 1 of them ( Nyctalus noctula) is successfully bred there.
A constant environment animal house suitable for nutritional research
Authors: McSheehy Trevor
Published: June 2007

Some of the problems associated with the design of a constant environment animal house are discussed, together with solutions in a specific example. Control of room temperature to ± 1°F (±0.6°C) and relative humidity to ± 1.5% was achieved at an overall capital cost of approximately £7 per square foot (£75/m2).
Estimation of milk yield in the rat
Authors: Morag M.
Published: June 2007

The biases inherent in the use of the growth curves of the litter and of milking devices to estimate milk yield in the rat are discussed. A method is described in which the pups are separated from their dams for a period of hours and are then allowed to suck for about 60 minutes. The increase in litter weight during suckling is used as an estimate of milk secretion during the period of separation. Various components of this method were examined and it was shown that (i) the rate of milk secretion in the rat is constant for at least 16 h; (ii) the administration of oxytocin at suckling does not influence the yield at that suckling, but does increase the rate of milk removal; (iii) gland evacuation is completed within 50 to 60 minutes of suckling; (iv) the emptying of the mammary gland prior to the secretion interval increases the sensitivity of the estimate of milk yield; (v) the yield after a standard period of separation is a function of the level of hunger of the litter prior to suckling; (vi) cross-fostering and frequent randomized reallocation of pups between treatment groups eliminate biases inherent in earlier methods. The problems associated with the technique are discussed and a laboratory routine is outlined. The use of the technique in cross-over designs is advocated.
Interstitial nephritis in the spiny mouse (Acomys cahirinus) associated with Klossiella sp. infection
Authors: Meshorer A.
Published: June 2007

Klossiella sp. infection in the spiny mouse ( Acomys cahirinus) was found associated with interstitial nephritis. The clinical disease appeared to be related to unsanitary housing conditions, and disappeared when hygiene was improved.
Evolution of the digestive microflora in a unit of specified-pathogen-free mice: efficiency of the barrier
Authors: Perrot A.
Published: June 2007

The qualitative and quantitative evolution of the digestive microflora of SPF inbred mice (C57BL/RhoIco strain), barrier-maintained since 1970, is described. Some 'contaminants' appeared spontaneously during the period 1971-1973, but microorganisms belonging to the genera Lactobacillus Streptococcus, Enterobacteria, Escherichia and Bacillus remained stable. The methods of investigation used were not suitable for the assessment of strictly anaerobic strains. The stability of the digestive microflora during the last 2 years of this study is believed to be related to the skill and conscientiousness of the technicians responsible for the daily care of these mice.
Fire alarms and oestrus in rats
Authors: Gamble M. R.
Published: June 2007

Vaginal smear cyclicity was used as a physiological test to compare the response of rats to the new 'silent' fire alarm developed by the Laboratory Animals Centre with a conventional fire bell.

The fire bell had a highly significant effect on the vaginal smear cyclicity whereas the rats exposed to the 'silent' fire alarm showed no significant changes from the control animals in quiet conditions.
Ammonia build-up in animal boxes and its effect on rat tracheal epithelium
Authors: Gamble M. R. , Clough G.
Published: June 2007

Some common laboratory species are now considered unsuitable for the study of the toxicity of inhalants because of the natural incidence of abnormal respiratory histology. Levels of ammonia commonly encountered in animal boxes and cages have been shown to cause histopathological changes in the tracheal epithelium of rats, and it is suggested that 'abnormal respiratory histology' could be a reflection of the standard of husbandry employed before and during an experiment.
Haemoglobin variants in mice
Authors: Randelia Homai P. , Naik S. N.
Published: June 2007

Haemoglobin variants were studied in wild and laboratory house mice ( Mus musculus), including standard and new inbred strains, using starch-gel electrophoretic technique. Single (Hbbs) or diffuse (Hbbd) types of haemoglobin were found in all of them. The embryonic haemoglobin pattern was different from although similar to that of the adult in all the strains. The haemoglobins revealed monomorphism in the inbred strains, while polymorphism was observed in non-inbred laboratory and wild mice.
Urolithiasis in the Sprague-Dawley rat
Authors: Paterson Michael
Published: June 2007

A 7 year collection of calculi from short- and long-term studies with Sprague-Dawley rats showed that although the incidence of rats with urolithiasis was small (0·5%), the variety of sizes and composition of the calculi could be of general interest.
Prevalence of indigenous viruses in laboratory animal colonies in the United Kingdom 1978-1979
Authors: Gannon J. , Carthew P.
Published: June 2007

Compared with the results of the previous serological survey of 1976-1977, it can be seen that mouse hepatitis virus is still prevalent in the mouse colonies and that corona viruses of rats are also common. The prevalence of Sendai virus has increased considerably. However, the prevalence of Reo 3 virus appeared to have decreased, although this may be the result of the different test used.
High incidence of dystokia in the casiragua (Proechimys guairae)
Authors: Jones D. M. , Pugsley S. L.
Published: June 2007

Dystokia caused the deaths of 8 casiraguas out of a total of 25 adult females examined post mortem from a small colony of this rodent on exhibition at the London Zoo.
Management of a colony of common kestrels (Falco tinnunculus) in captivity
Authors: Kirkwood James K.
Published: June 2007

Management and captive breeding techniques of the kestrel are described. 5 pairs of kestrels laid 48 eggs in 1979, 27 of which were artificially incubated producing 19 hatchlings.
Calcification in the adrenals and ovaries of monkeys
Authors: Majeed Saleh K. , Gopinath C.
Published: June 2007

Adrenal calcification occurred in 52·6% of rhesus monkeys, 4·7% of cynomolgus monkeys and 2·4% of baboons examined. In contrast, ovarian calcification was observed in 62·3% of baboons, 38% of cynomolgus and 22·3% of rhesus monkeys examined.
Naturally acquired infections of Klebsiella pneumoniae in Wistar rats
Authors: Jackson N. N. , Wall H. G. , Miller Charlotte A. , Rogul M.
Published: June 2007

Klebsiella pneumoniae was isolated from lesions in 2 dead and 82 ill animals in a breeding colony of 2300 Wistar rats. The clinical signs were unilaterial and bilateral fluctuating masses in the cervical and inguinal areas, and focal cutaneous ulcers in the ventral neck. Cervical and inguinal lymphadenitis with abscess formation were found on microscopic examination. Lesions also occurred in visceral organs. Although characteristic of the natural infection in most species, no respiratory lesions were seen in this epizootic episode. A capsular serotype 5 K. pneumoniae which did not utilize malonate was the only bacterial strain cultured from the lesions, but other K. pneumoniae strains that utilized malonate and were untypable by capsular serology were cultured from throats and faeces. 30% (6/20) of asymptomatic animals tested had both types of K. pneumoniae in their faeces.
Infectious sialodacryoadenitis and rat breeding
Authors: Utsumi Kenjiro , Ishikawa Takashi , Maeda Toshihiro , Shimizu Shinjiro , Tatsumi Hiroshi , Fujiwara Kôsaku
Published: June 2007

The littering rate of female rats was significantly lowered when they had been exposed to sialodacryoadenitis early in pregnancy. Rats of 8 weeks or more of age were highly susceptible to contact infection, showing marked decrease in bodyweight gain, whereas those of 5-6 weeks of age were resistant.
Reproductive performance of rabbits on a low protein diet
Authors: Adams C. E.
Published: June 2007

The growth and reproductive performance of rabbits reared on diet 18 and transferred to diet R14 (low protein/energy ratio) for (a) 3-4 weeks prior to mating or (b) 4 weeks prior to mating and throughout pregnancy were examined. Observations are presented on bodyweights, size and colour of the vulva and mating behaviour, pregnancy rate, and neonatal mortality. No significant differences were noted in comparison with 'controls' receiving Diet 18.
An outbreak of Bordetella bronchiseptica pneumonia in a colony of common marmosets (Callithrix jacchus)
Authors: Baskerville Margaret , Wood Margery , Baskerville A.
Published: June 2007

An outbreak of Bordetella bronchiseptica pneumonia occurred in a breeding colony of common marmosets ( Callithrix jacchus). 16 animals, all except one under 12 months of age, died suddenly. Extensive lesions of pneumonia and pleurisy were found at necropsy and B. bronchiseptica was isolated from the nasopharynx, trachea and lungs. Older animals had only a mild rhinitis. Colonization of the nasal mucosa occurred in 71 of 156 marmosets.
The effect on rats of practical diets containing different protein and energy levels
Authors: Ford D. J. , Ward R. J.
Published: June 2007

Rats of 3 strains were fed diets of natural ingredients in 4 different laboratories. The diets contained different levels of protein and energy within ranges comparable to those found in existing laboratory diets. Energy level over the range examined appeared to exert greatest influence on bodyweight gain, but had no effect on food intake. The diet with the highest amino acid content was consumed in smaller amounts than the other diets. Food utilization was less efficient in the lower energy diets. Fat deposition was reduced in animals fed the lowest energy diet. It is concluded that energy level of the diet exerts an effect on the rate of bodyweight gain in rats, but that for longer-term studies a reduced energy level may be beneficial by leading to smaller fat deposits with consequent increase in longevity.
The effect on mice of practical diets containing different protein and energy levels
Authors: Ford D. J. , Ward R. J.
Published: June 2007

Mice of 2 strains were fed diets of natural ingredients in 3 different laboratories. The diets, which were fed before and after pelleting, contained levels of protein and energy within the ranges comparable to those found in existing laboratory diets and were the same formulation as those fed to rats in a previous paper. The diet with the lowest energy level supported the lowest rate of bodyweight gain, as it had with rats. Little effect was noticed on food consumption, conversion efficiency or water intake. Animals fed the pelleted diets gained bodyweight faster and there were indications of greater food and water consumption and also food conversion efficiency. It was concluded that food intake was improved with the pelleted diets resulting in the other increases.
Hereditary erythroblastic anaemia in the laboratory mouse
Authors: Shimizu K. , Keino H. , Ogasawara N. , Esaki K.
Published: June 2007

Hereditary erythroblastic anaemia was found in a homozygous mutant ( hea/hea) of an inbred strain CFO, which originated from noninbred CF#1 mice from Carworth Inc. This newly-described anaemia is inherited as an autosomal recessive and is lethal at 15-25 days of age. Erythrocytes of anaemic mice show striking polychromasia, anisocytosis, and poikilocytosis. One of the most marked features of this anaemia is the presence of large numbers of nucleated cells, mainly orthochromatophilic erythroblasts and myeloid cells, in the circulation. They also include immature erythroid and myeloid cells. Many naked nuclei appear on smears from circulating blood of anaemic infants. Erythrocytes, haematocrit percentage, and haemoglobin content of older anaemic infants were only about 50% of those of the normal. Formation of erythroid, myeloid cells, and megakaryocytes in the bone marrow seems to be progressively affected by mutant alleles in the anaemic infants.
Some aspects of the gastrointestinal microflora of germfree mice associated with cultured microfloras
Authors: Koopman J. P. , Kennis Henriëtie M. , Stadhouders A. M. , De Boer H.
Published: June 2007

Attempts are described to 'normalize' germfree mice by association with 3, 21 and 71 different intestinal bacterial cultures isolated from mice with an SPF flora. Germfree mice associated naturally with an SPF flora served as controls. Vital bacterial counts were determined by aerobic and anaerobic culture. Stomach and small intestine contained fewer bacteria per gram than caecum and large intestine. Aerobic vital counts from caecum and large intestine were higher in the experimental groups than in control mice. The aerobic and anaerobic flora in stomach and small intestine comprised mainly Gram-positive nonfusiform shaped rods. In the caecum and colon Gram-positive cocci predominated in the aerobic culture while in the anaerobic culture fusiform-shaped rods were prominent. Scanning electron microscopy of oesophagus, ileum, caecum and faeces demonstrated colonization of the oesophageal epithelium only after association with 71 bacterial strains; the filamentous bacteria present in the ileum of SPF mice were not found in the experimental groups and caecum and faeces contained mainly fusiform-shaped bacteria. Nonbacterial matter decreased in the caecum and faeces with increase in the complexity of the flora.
Abnormality of an index of alveolar-capillary barrier permeability associated with respiratory tract infection in the rat
Authors: Royston D. , Minty Barbara D. , Needham J. R. , Jones J. G.
Published: June 2007

The study investigated the role of subclinical respiratory tract infection in producing an abnormality of lung function assessed by measuring an index of the permeability of the blood-gas barrier to 99mTcDTPA. Pasteurella pneumotropica was grown from throat swabs taken from 9 female rats age 10 weeks at the time of the experiment and housed under conventional husbandry conditions for 4 weeks previously. There was a significant association between the amount of bacteriological growth and an abnormality of the index of permeability. In contrast to this finding, there was no bacterial growth and no abnormality of function found in 12 female rats age 6 weeks, kept under strict barrier-maintained conditions. This finding emphasises the need for great care to be taken in the husbandry of animals used in scientific research.
Clinical salmonellosis in a guineapig colony caused by a new Salmonella serotype, Salmonella ochiogu
Authors: Onyekaba C. O.
Published: June 2007

During a severe outbreak of clinical salmonellosis in an experimental guineapig colony, a new strain of Salmonella was isolated and identified. The new serotype, with the antigenic structure 1,3,19 : Z38 : e, n, Z15, for which the name Salmonella ochiogu has been suggested, caused both enteric and systemic infection in the animal colony. During the outbreak a total of 127 animals died (26·9%). All ages of animal were affected. Treatment with oral tetracycline was successful when combined with strict hygienic measures.
Experimental iron deficiency in Syrian hamsters (Mesocricetus auratus)
Authors: Ranasinghe A. W. , Johnson N. W. , Rountree R.
Published: June 2007

An animal model was developed in which the effect of iron deficiency on the oral mucosa could be studied. Iron deficiency was induced by feeding hamsters a low-iron powdered diet together with withdrawal of 0·5 ml of blood weekly, for a period of 9 weeks. At the end of this period the mean haematological values for control animals were, Hb 15·9 g/dl, plasma iron 40·3 μmol/l, TIBC 90·5 μmol/l and transferrin saturation 44·5%, compared with 7·4, 7·2, 111·4 and 6·5 respectively for experimental animals. These results were reproducible in successive groups of animals and indicate that this is a useful model for the study of iron deficiency anaemia.
Dermatitis in nude mice (nu/nu) associated with Staphylococcus pyogenes
Authors: Moore G. J.
Published: June 2007

Nude mice ( nu/nu on BALB/cAn background), maintained under conventional conditions, developed an acute moist dermatitis of the nose and occasionally the ears, with heavy contamination with Staphylococcus pyogenes. Only homozygotes over 10 weeks old were affected. Treatment with parenteral ampicillin or oral oxytetracycline was ineffective. Other conditions associated with the same organism were conjunctivitis and periorbital abscesses.
Catheterization of the sagittal sinus in the neonatal pig
Authors: Flecknell P. A. , John Muriel
Published: June 2007

A method is described for catheterization of the sagittal sinus in the neonatal pig. Using this technique, cerebral venous blood can be collected from conscious unrestrained animals for a period of at least 4 days.
Factors influencing population growth of a colony of cotton-top tamarins
Authors: Kirkwood J.K. , Epstein M. A. , Terlecki A. J.
Published: June 2007

43% of full-term births in a colony of Saguinus oedipus oedipus occurred during April and May. Interbirth interval was usually 12 months in females which reared live young and 7 months in those whose young died perinatally. 81% of all full-term births were of twins, the rest were singles. High mortality among neonates was seen with a group of bought-in animals which had been taken from their parents at an early age without participating in the rearing of siblings, and was attributable to parental incompetence. Colony management aiming to ensure that animals gain experience in caring for young before breeding is described. Mortality among all animals older than 7 days was very low. Marginal protein deficiency may have been involved in a chronic diarrhoea and weight loss syndrome seen in some animals. They recovered after addition of hard-boiled egg to the diet.
Suboccipital puncture of guineapigs
Authors: Reiber H. , Schunck O.
Published: June 2007

Cisternal cerebrospinal fluid (CSF) was tapped from anaesthetized guineapigs by an improved technique. This method allowed repeated weekly punctures of the same animal without any cellular or neurochemical changes in CSF or changes in behaviour. About 60% of the punctures produced enough CSF (30-330 μl) with no or a sufficiently low blood contamination for neurochemical analysis. The CSF space in the spinal canal, cisterna magna and basal cisterns was demonstrated by myelography.
Relationships of volatile components and bacterial flora in mouse caecum
Authors: Imai Akihiro , Morishita Keiko
Published: June 2007

The relations between volatile components and bacterial flora in mouse caecum were studied in germ-free, gnotobiotic and SPF mice and in gnotobiotes given heated caecal homogenate from SPF mice. Anaerobic fusiform bacteria were present in SPF mice and ex-gnotobiotic (gnotobiotic plus SPF caecum) mice only. Low concentrations of furfural correlated with the presence of intestinal fusiform bacteria, suggesting that furfural may be decomposed by these organisms. Fusiform bacteria were also associated with the highest concentrations of acetic and butyric acids and may play an important role in regulating the composition of the mouse caecal flora.
Myeloproliferative disease in a cotton-top tamarin (Saguinus oedipus oedipus)
Authors: Kirkwood J. K. , James M. P.
Published: June 2007

The pathology of a case of myeloproliferative disease in an adult male cotton-top marmoset Saguinus oedipus oedipus is described.
Regional differences in blood flow in relation to tumour growth in the mouse
Authors: Minasian Harvey
Published: June 2007

The regional distribution of radio-isotopes was used to estimate regional differences in the cutaneous and mammary gland blood flow in the mouse. The observed values were greater in the cranial than caudal regions. The association of these findings with the reported higher tumour growth rate in the cranial than caudal aspect of the mouse is discussed.
A method for producing forced expirograms in laboratory animals
Authors: Ventrone R. , Musy C. , Coggins C. R. E.
Published: June 2007

A method is described for the production of forced expirograms in anaesthetized laboratory animals, using a whole-body plethysmograph and a Hewlett-Packard (HP) 1000-Fcomputer.
A better method for terminal bleeding of mice
Authors: Adeghe A. J.-H. , Cohen J.
Published: June 2007

A new method for exsanguinating mice is described. The procedure is carried out under CO2-anaesthesia and involves venepuncture of the caudal (inferior) vena cava and gentle aspiration of blood into a syringe. It consistently gives large volumes of blood (1·60-2·50 ml/mouse), free from haemolysis and contamination. The technique is easy, quick and reliable.
Paresis of peristalsis and ileus lead to death in lactating mice
Authors: Kunstýř I.
Published: June 2007

Based on the examination of 45 dead and 5 moribund female mice during a 2-year period, we are able to describe a new disease entity: ileus of the small intestine in lactating mice caused by a paresis of peristalsis. Diarrhoea was not observed and innammation and infectious agents were not found. Females were affected during the 2nd week of their first lactation. The condition may have a mortality rate as high as 40%. It is assumed that exhaustion (calcium, glucose, etc.) is the cause of this condition. Consequently, the development of a dietary supplement or of a special diet for lactating mice may prove beneficial in preventing this disease. Endogenic (Clostridia) or exogenic toxic components may also playa role.
Determining the viability of faecal bacteria present in germ-free mice
Authors: Taylor D. M. , Read Lesley , Neal D. L.
Published: June 2007

Gram-positive bacilli, originating from the diet, are present in the faeces of germ-free mice in this Unit. Although these organisms have never grown on culture and are assumed to be dead it was considered desirable to test this by non-cultural methods because some gut bacteria are difficult or impossible to grow in vitro by present techniques. Germ-free mice were fed a synthetic diet free from live or dead organisms for 10 days during which time the bacilli disappeared from the faeces, re-appearing when the usual diet was re-introduced. This was regarded as confirmation of the non-viability of the bacilli. The use of Wayson's stain for confirmation of non-viability was found to be inappropriate since it produced false-positive reactions with irradiation-killed bacteria.
Strain differences in faecal tryptic activity of germ-free and conventional rats
Authors: Norin K. Elisabeth , Gustafsson B. E. , Midtvedt T.
Published: June 2007

Regardless of diet (semi-synthetic or lab chow) or strain (AGUS or SD), germ-free rats have tryptic activity in their faeces, whereas conventional rats never do. The activity in faeces from germ-free AGUS rats was significantly higher than from SD rats.
Local myotoxicity of ketamine hydrochloride in the marmoset
Authors: Davy C. W. , Trennery P. N. , Edmunds J. G. , Altman J. F. B. , Eichler D. A.
Published: June 2007

An investigation of raised plasma aspartate aminotransferase (AST) in marmosets after intramuscular ketamine injection suggested a local myotoxicity. This was confirmed by a range of histopathological findings from myofibrillar striation loss to necrosis. In addition to the elevations in AST levels, creatine kinase and the lactate dehydrogenase-5 isoenzyme levels were elevated. It was further demonstrated that, although the physical properties of the injectable solution (pH, osmolality) and to a lesser extent the injection procedure itself caused slight changes in plasma enzyme levels, the ketamine was predominantly responsible for the lesion. No hepatic interactions were seen. This effect should be taken into consideration when this anaesthetic is used in the marmoset if the primary objectives of the experiment entail routine blood analyses.
The attachment of filamentous segmented micro-organisms to the distal ileum wall of the mouse: a scanning and transmission electron microscopy study
Authors: Koopman J. P. , Stadhouders A. M. , Kennis H. M. , De Boer H.
Published: June 2007

Scanning electron micrographs are presented of the ileal epithelium of mice aged 5, 15, 20 and 25 days. During this period the villous pattern develops to full maturity. By the twentieth day of life a segmented filamentous micro-organism colonizes the ileal epithelium and is firmly attached via a small segment. During the first days of colonization the segmented filamentous micro-organisms themselves are subcolonized by small rod-shaped bacteria, presumably lactobacilli. At the age of 25 days this subcolonization was no longer observed.
Studies on beige–nude mice with low natural killer cell activity 1. Introduction of the bg gene into nude mice and the characteristics of beige–nude mice
Authors: Hioki K. , Maruo K. , Suzuki S. , Kato H. , Shimamura K. , Saito M. , Nomura T.
Published: June 2007

To improve the take-rate of human tumours in nude mice, a nude mouse strain with the bg gene was established. The introduction of the bg gene was confirmed by examination of giant granules of blood neutrophils. The genetic profile of beige–nude mice was the same as that of the C57BL/6 strain according to genetic screening. The natural killer cell activity in the beige–nude mice was much lower than that in ordinary nude mice but slightly higher than that in beige mice. The reproductivity of beige–nude mice was as high as that of ordinary nude mice.
Calcified foci at the junction between adrenal cortex and medulla of rhesus monkeys
Authors: Kast Alexander , Peil Hubertus , Weisse Ingo
Published: June 2007

The occurrence of calcified foci at the junction of adrenal medulla and cortex in monkeys obtained from toxicity studies during a 10-year period is reported. The survey included reinvestigated adrenal samples from 274 male and 270 female rhesus monkeys and 52 male and 52 female cynomolgus monkeys. The incidence of calcified foci was 46% in male and 45% in female rhesus monkeys, and 6% in male cynomolgus monkeys, while their females did not show the lesion. In male rhesus monkeys, the mean number of foci was 4 for both glands, in females, 2 for the right and 4 for the left one. Initial stages indicated that the lesions develop possibly from focal apoptosis of medulla cells followed by a dystrophic mineralization. No correlation was observed concerning dose groups, test article, study length, testing facility, origin of monkeys, their sex, age, diet or final body weight. The foci of mineralization were dystrophic, species-specific in the rhesus monkey and possibly related to stress. The location of the foci at the cortico-medullary junction, precisely the location of the remnants of the fetal zone, may indicate their origin from this zone.
Guidelines for the welfare of animals in rodent protection tests: A Report from the Rodent Protection Test Working Party
Authors: Acred P. , Hennessey T. D. , MacArthur-Clark J. A. , Merrikin D. J. , Ryan D. M. , Smulders H. C. , Troke P. F. , Wilson R. G. , Straughan D. W.
Published: June 2007

The rodent protection test (RPT) is used in antimicrobial research to confirm the in vivo efficacy of novel antibacterial, antiviral and antifungal agents. The RPT may involve lethal infection and thus has the potential to cause significant suffering. These Guidelines recommend refinements to the RPT which reduce animal use to a minimum and suggest cardinal clinical signs which act as predictors of lethality. Early recognition of these signs is imperative to minimize suffering, allow identification of humane end points and permit timely euthanasia. Constructive suggestions for the improvement of these Guidelines are welcomed.
Anew method of faeces collection in the pig
Authors: van Kleef D. J. , Deuring K. , van Leeuwen P.
Published: June 2007

A new faeces collection method for pigs has been developed which allows collection of faeces into a plastic bag. This new method greatly reduces faecal losses and thereby permits virtually complete collection of faecal material. The method can be applied easily and causes less discomfort to the animals than previous methods.
RNA-based regulation of genes of tryptophan synthesis and degradation, in bacteria
Authors: Yanofsky Charles
Published: June 2007

We are now aware that RNA-based regulatory mechanisms are commonly used to control gene expression in many organisms. These mechanisms offer the opportunity to exploit relatively short, unique RNA sequences, in altering transcription, translation, and/or mRNA stability, in response to the presence of a small or large signal molecule. The ability of an RNA segment to fold and form alternative hairpin secondary structures—each dedicated to a different regulatory function—permits selection of specific sequences that can affect transcription and/or translation. In the present paper I will focus on our current understanding of the RNA-based regulatory mechanisms used by Escherichia coli and Bacillus subtilis in controlling expression of the tryptophan biosynthetic operon. The regulatory mechanisms they use for this purpose differ, suggesting that these organisms, or their ancestors, adopted different strategies during their evolution. I will also describe the RNA-based mechanism used by E. coli in regulating expression of its operon responsible for tryptophan degradation, the tryptophanase operon.
Information System Use–Related Activity: An Expanded Behavioral Conceptualization of Individual-Level Information System Use
Authors: Barki Henri , Titah Ryad , Boffo Céline
Published: June 2007

Despite calls for improving current approaches to conceptualizing and measuring the construct of information system use, theoretical advances in this regard are still insufficient. The present paper proposes to expand the focus of existing conceptualizations that exclusively focus on technology interaction behaviors via the construct of IS use-related activity. Based on task-technology fit and activity theory, IS use-related activity is conceptualized as a second-order aggregate construct that comprises both technology interaction behaviors, as well as activities users undertake to adapt the task-technology-individual system. A multiple-indicators and multiple-causes analysis of data collected from 190 users in 21 organizations is found to support the proposed conceptualization.
Research Note—Statistical Power in Analyzing Interaction Effects: Questioning the Advantage of PLS with Product Indicators
Authors: Goodhue Dale , Lewis William , Thompson Ronald
Published: June 2007

A significant amount of information systems (IS) research involves hypothesizing and testing for interaction effects. Chin et al. (2003) completed an extensive experiment using Monte Carlo simulation that compared two different techniques for detecting and estimating such interaction effects: partial least squares (PLS) with a product indicator approach versus multiple regression with summated indicators. By varying the number of indicators for each construct and the sample size, they concluded that PLS using product indicators was better (at providing higher and presumably more accurate path estimates) than multiple regression using summated indicators. Although we view the Chin et al. (2003) study as an important step in using Monte Carlo analysis to investigate such issues, we believe their results give a misleading picture of the efficacy of the product indicator approach with PLS. By expanding the scope of the investigation to include statistical power, and by replicating and then extending their work, we reach a different conclusion—that although PLS with the product indicator approach provides higher point estimates of interaction paths, it also produces wider confidence intervals, and thus provides less statistical power than multiple regression. This disadvantage increases with the number of indicators and (up to a point) with sample size. We explore the possibility that these surprising results can be explained by capitalization on chance. Regardless of the explanation, our analysis leads us to recommend that if sample size or statistical significance is a concern, regression or PLS with product of the sums should be used instead of PLS with product indicators for testing interaction effects.
Issues and Opinions—Those to Whom IT Matters Most: Perspectives of IT Faculty on Curricula, Courses, and Class Materials
Authors: McAfee Andrew
Published: June 2007

This paper presents quantitative and qualitative results from a conference on IT teaching held in May of 2006 in Boston. Participants completed a survey in advance, and the conference consisted of presentations and interactive panel discussions. The conference revealed both heterogeneity and convergence across participants’ course offerings, and grounds for both optimism and concern about the health and future of IT curricula within business schools. This paper highlights these tensions, synthesizes and extends data and discussions from the conference, and suggests open questions for faculty who teach IT.