Small animals are not susceptible to human immunodeficiency virus infection

Several species of small animals were inoculated at birth or as adults with blood components from patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related disorders, or with the human immunodeficiency virus (HIV). No ill effects were noted in rats, hamsters, guinea-pigs, rabbits or musk shrews. Mice inoculated with clinical specimens had a significant incidence of mortality as compared with control groups (18.7% against 5.9%, P less than 0.025). Mice receiving HIV showed an increase in mortality, but it was not statistically significant. Infection of the animals by HIV could not be detected by virological or immunological studies. We concluded that none of these animal species provided a useful model for evaluating HIV infection.

Augmentin bioavailability following cimetidine, aluminum hydroxide and milk

Previous studies [Jackson et al. 1980] have shown that the bioavailability of Augmentin is not affected by food. The present work has shown that aluminum hydroxide, milk and cimetidine do have some influence on the bioavailability of a single dose of oral Augmentin, but the small differences observed are unlikely to be of therapeutic importance. It is concluded that Augmentin may be administered in clinical practice with any of these substances.

Starvation and feeding with a high-carbohydrate diet induce changes in the specific activity of rat hepatic pyruvate kinase

A highly specific radiosandwich assay for hepatic type-L pyruvate kinase (PK) determinants was developed. This assay was used to evaluate changes in PK specific activity which occur on starvation or feeding with a high-carbohydrate diet. Despite a large increase in both catalytic activity and immunoreactive protein, the calculated specific activity falls on feeding, and the opposite effect occurs on starvation. These change can be attributed to disproportionate changes in immunoreactive protein compared with changes in catalytic activity.

Reproducibility of an index for recording the alignment of individual teeth

In order that relationships between dental irregularities and the caries and periodontal status of individual teeth can be examined, the STRAIT index (standardized technique for recording the alignment of individual teeth) was developed. Tooth position scores representing vertical relationship, rotation, mesio-distal inclination, displacement and radial relationship are recorded using three- or five-category scales. Contact point scores representing bucco-lingual and mesio-distal relationships are measured directly. These characteristics are recorded for each tooth in the dentition, together with overjet and overbite measures for maxillary incisors and canines. Repeat measurement of 50 sets of models was undertaken by two examiners in order to assess intra-and interreproducibility of the index. A formula for adjusted agreement was employed for analysis of the categorized variables, and reproducibility was typically 80 per cent or better. Analysis of the reproducibility of the continuous variables was based on calculation of root mean square values of the difference between data sets and t-tests. In the main, intra- and interreproducibility was within 0.5 mm. These levels of accuracy meet the requirements of the index and it has since been used in an investigation of 1000 subjects.

Murine xenotropic type C viruses. IV. Replication and pathogenesis of ducks

The xenotropic (X-tropic) mouse type C virus (MuLV) and its pseudotype of murine sarcoma virus (MSV) were inoculated into several fertilized developing Pekin duck eggs. The development of the duck embryos was substantially reduced in those receiving the X-tropic viruses compared to eggs inoculated only with tissue culture medium. Infections virus was isolated from some of the adult animals; in others, evidence for integrated virus sequences in the tissues was noted. No specific pathology was found in the ducks that received X-trophic MuLV alone, but one duck developed multiple fibrosarcomas when inoculated at birth with the X-tropic virus pseudotype of MSV. Two ducks receiving X-tropic MuLv had signs of haematopoietic disorders. In addition, more virus-inoculated animals had evidence of hepatitis and encephalitis than control ducks. Antibody production to X-tropic MuLv was present in several ducks inoculated with virus either in embryo or at birth. Absence of antiviral antibodies was noted in those animals whose tissue contained replicating virus. These studies confirm the observations with X-tropic virus in tissue culture. They demonstrate in vivo that avian species are susceptible to infection by the mouse X-tropic virus and that their fibroblasts can be transformed by the X-tropic MuLV pseudotype of MSV.

Food use and perceived food meanings of the elderly

Food use frequency and food perception analyses were used to assess food use patterns of non-institutionalized, subjectively healthy seniors, aged 65 to 77 years and living alone. The majority of the sample maintained variety and nutritional balance in food selection; the women showed greater use several items, particularly fruits and vegetables. Tea, whole wheat bread, eggs, coffee, potatoes, margarine, carrots, and orange juice ranked highest in the core food list. Perceived taste and health beliefs were strong motives in food selection.

Renin in rat and mouse brain: immunohistochemical identification and localization

1. Localization of renin in rat and mouse brain was determined by immunohistochemical methods with specific anti-renin antibodies. 2. Renin-containing neuronal cells were found in the medulla oblongata, cerebellar nuclei and hypothalamus. Purkinje cells contained renin. 3. Glia-like cells contained renin. Some of them are closely associated with vascular walls and these vascular walls were renin positive. 4. The pineal gland, adenohypophysis and choroid plexus contained renin. 5. The extensive distribution of renin suggests functions other than those which have been associated with the hypothalamus.

Social determinants in food selection

Responses of 112 low-income homemakers to questions about the food use frequency, availability, and social determinants (convenience, price, and prestige) of fifty-two food items are reported. Results indicate that foods have clear meaning profiles that can be measured on attitudinal scales. Bivariate analysis was used to illustrate the interrelationships between food-use frequency and social determinants. Significant correlations were found between food use and convenience, price, prestige, and availability for fourteen of the fifty-two food items studied.

[Effect of methylprednisolone on bacterial infection of the peritoneal cavity in the guinea pig]

There is clinical proof of the decisive therapeutic effect of bolus injection of corticosteroids in septic shock. Our own studies, in which sublethal doses of bacterial suspensions were introduced into the peritoneal cavity of guinea pigs, demonstrate that a simultaneously applied solution of methylprednisolone (MP) has no influence on the intraperitoneal number of bacteria. Even the rapid initial decrease of bacterial counts, which, according to our studies, can be inhibited by Liquoid and is, therefore, caused by complement, is not influenced by the addition of MP. There was no indication of a change of tissue reactions in gut or mesenterium. The therapeutic effect of corticosteroids seems to depend on its influence on peripheral vessels.

Effect of acetoacetate on glucose metabolism in the soleus and extensor digitorum longus muscles of the rat

1. The effect of acetoacetate on glucose metabolism was compared in the soleus, a slow-twitch red muscle, and the extensor digitorum longus, a muscle composed of 50% fast-twitch red and 50% white fibres. 2. When incubated for 2h in a medium containing 5 mM-glucose and 0.1 unit of insulin/ml, rates of glucose uptake, lactate release and glucose oxidation in the soleus were 19.6, 18.6 and 1.47 micronmol/h per g respectively. Acetoacetate (1.7 mM) diminished all three rates by 25-50%; however, it increased glucose conversion into glycogen. In addition, it caused increases in tissue glucose, glucose 6-phosphate and fructose 6-phosphate, suggesting inhibition of phosphofructokinase. The concentrations of citrate, an inhibitor of phosphofructokinase, and of malate were also increased. 3. Rates of glucose uptake and lactate release in the extensor digitorum longus were 50-80% of those in the soleus. Acetoacetate caused moderate increases in tissue glucose 6-phosphate and possibly citrate, but it did not decrease glucose uptake or lactate release. 4. The rate of glycolysis in the soleus was approximately five times that previously observed in the perfused rat hindquarter, a muscle preparation in which acetoacetate inhibits glucose oxidation, but does not alter glucose uptake or glycolysis. A similar rate of glycolysis was observed when the soleus was incubated with a glucose-free medium. Under these conditions, tissue malate and the lactate/pyruvate ratio in the medium were decreased, and acetoacetate did not decrease lactate release or increase tissue citrate or glucose 6-phosphate. An intermediate rate of glycolysis, which was not decreased by acetoacetate, was observed when the soleus was incubated with glucose, but not insulin. 5. The data suggest that acetoacetate glucose inhibits uptake and glycolysis in red muscle under conditions that resemble mild to moderate exercise. They also suggest that the accumulation of citrate in these circumstances is linked to the rate of glycolysis, possibly through the generation of cytosolic NADH and malate formation.

Turnover of plasma oleic acid measured by radio-gas chromatography

Gas-liquid chromatography with radioactivity detection (Radio-GLC) was investigated as an analytical means of determining the fractional turnover rates of plasma free fatty acids. For this purpose normal dogs were infused with 1.838 muCi/min of [1-14C]oleic acid complexed with albumin and plasma samples were taken at 0 to 110 minutes. The plasma free fatty acids were isolated by a modified Dole extraction and the methyl esters, prepared by diazomethylation, were identified and quantitated by GLC and radio-GLC using radioactive methyl heptadecanoate as internal standard. The study demonstrates that physiologically feasible infusion rates and loads of radioactive acids can be found which permit accurate analyses of plasma free fatty acids by radio-GLC. During a 2-hour infusion no labeled acid other than oleic appeared in plasma indicating that the method could be used to study the turnover of a mixture of fatty acids simultaneously. These results also indicate that conventional methods of determination of radioactivity in purified extracts can be employed without concern for recycling of label among the fatty acids, at least over short periods of time. The radio-GLC technique described yields approximately 20% higher fractional turnover times for oleic acid than do standard methods.

Experimental validation of nonsteady rate measurements using a tracer infusion method and inulin as tracer and tracee

In 1959, Steele (Ann. N.Y. Acad. Sci. 82, 420–430) suggested a method for measuring the rates of appearance (Ra) and of disappearance (Rd) of a metabolite in an intact system under conditions when Ra and Rd were changing with time. Steele's method involved modelling the system by a one-compartment model whose effective volume was assumed. To overcome the problem of assuming an effective volume, a model consisting of two compartments rather than one has been postulated. While no distribution volume need now be assumed, a preliminary steady state experiment is required for identification of the coefficients governing exchange of material between the two compartments.In five conscious dogs 14C-hydroxymethyl inulin (tracer) was infused at a constant rate, while unlabelled inulin (tracee) was infused at varying predetermined rates and the plasma concentrations of both were measured. These were then fitted by a series of smoothly joined polynomials. When the calculated rates of appearance of unlabelled inulin were compared with the actual rates, equally good results were obtained with the one-compartment (using the best effective volume) and the two-compartment models. The calculated values of Rd and of the clearance of inulin were not validated experimentally, but their validity is likely since the equations for Rd and Ra are related, and the Ra component has been validated. The identity of unlabelled inulin and the 14C-hydroxymethyl inulin species was ascertained by gel filtration, and by the identity of their in vivo kinetics.