Comparative metabolism of the amphetamine drugs of dependence in man and monkeys

The use of animal models to study drug dependence and tolerance requires that the species used metabolizes the drugs like man, a condition frequently not fulfilled by non-primate species. The metabolic fate of several amphetamine drugs, namely amphetamine, norephedrine, chlorphentermine and phenmetrazine, in the rhesus monkey and the tamarin and two non-primate species has been investigated and compared to that found for man. The findings show that the two primate species metabolize these drugs in a manner similar to that in man.

Quantitative measurement of left ventricular volumes in man from radiopaque epicardial markers

The distances between three or four radiopaque markers located on the left ventricular epicardial surface at the apex and in the region of the minor axes in 22 subjects showed close correlations with left ventricular chamber radii, length, volume and wall thickness determined from biplane angiograms over the range of stroke volume. The markers were previously placed during heart surgery. Regression equations relating the distances between epicardial markers and chamber volumes were used to predict volumes for other beats. There was close agreement of end-diastolic, end-systolic, and stroke volumes as determined by the angiographic and epicardial marker methods for premature atrial contraction beats and post premature contraction beats, and in studies performed during rest and exercise. Time-volume curves determined by the epicardial marker and angiographic methods were similar. It is concluded that epicardial marker measurements can be used to quantitate beat-to-beat left ventricular chamber volume and dimension changes.

In vitro binding of sterols by extracts from Mucor rouxii cells grown under different environmental conditions

Aqueous cell wall and cytoplasm extracts from Mucor rouxii cells grown under acrobic and anaerobic (oxygen-limiting) conditions were obtained. Both of the extracts from the anaerobic and aerobic cells solubilized lanosterol and ergosterol but not to the same extent; ergosterol was complexed about 2-3 times greater than the same concentration of lanosterol. It was also apparent that the relative bindingcapacities of the cell extracts were dependent on the cell growth environment. Two additional fractions were obtained from each extract by (a) methanol precipitation and (b) refluxing in 2% aqueous potassium hydroxide solution followed by methanol precipitation. The binding activities of these precipitates and the corresponding precipitates from yeast extract were compared and the results indicated a range of binding activites which depended on both the extract and the sterol. The data suggested that the in vitro sterol binding of M. rouxii extracts was not due to one particular macromolecule but that a number of compounds were involved in this complexation process.

Radioimmunoassay of serum alpha-fetoprotein in patients with different maliganant tumors

The level of serum alpha-fetoprotein (AFP) was estimated by radioimmunoassay in 153 normal healthy Malysians of different ethnic groups. The mean level was 7.5 In1/ml (SD 2.28InU/ml). Among 330 patients with malignant tumors, 11 had increased levels of AFP. The only patient who had hepatoma had a very high level of serum AFP. High levels were also found in three of four patients with dysgerminoma of the ovary, in the only two patients with carcinoma of the testis, and in one patient with secondary carcinoma of the humerus of unknown origin. Lower, but significantly increased levels were observed in one patient (of 48) with breast carcinoma, one patient (of 8) with basal cell carcinoma of the nose, one patient (0f 27) with carcinoma of the lung, and one patient (of 59) with nasopharynegeal carcinoma.

Post-mortem survival of hippuric acid formation in rat and human cadaver tissue samples

1. A rapid and sensitive semi-micro method for the determination of hippuric acid formation by tissue samples in vitro is described and applied to the determination of the post-mortem survival of hippuric acid formation in rat and human cadaver tissue samples. 2. Hippuric acid formation survived in rat and human cadaver liver for at least 72 h when corpses were stored at 4 degrees. 3. Hippuric acid formation was detected in human cadaver liver and kidney samples and was absent from brain, intestine, heart and lung. 4. Post-mortem liver samples from a case of acute pancreatitis failed to form hippuric acid as did kidney samples from a case of systemic lupus erythematosus with renal involvement.

The changing African family project: a report with special reference to the Nigerian segment

The Changing African Family Project was begun in 1973 as a cooperative venture of the Sociology Department of the University of Ibadan and the Demography Department of the Australian National University, with research institutes and individual researchers in 11 representative countries of Africa, to investigate the preconditions for fertility decline. This paper reports initial initial findings from the large Nigerian segment of the project, which was used as a laboratory, and presents technical information about the surveys, as well as findings on economic supports for high fertility, factors affecting fertility, the role of sexual abstinence in determining fertility levels, the increase in contraception and its relation to family size limitation, and the incidence and nature of achieved small families. Information is also provided on the projects in Cameroon, the Congo (Brazzaville), Ghana, and the Sudan.

Immunologic basis for vaccination against dental caries in rhesus monkeys

The effects of immunization with Streptococcus mutans on the development of caries and the immune responses were investigated in 37 young rhesus monkeys (Macaca mulatta) during a period of up to 33 months. The monkeys were supplied a human type of carbohydrate-rich diet that contained about 15% sucrose. The monkeys were separated into seven groups, and the effects of two whole cell vaccines and an extracellular culture extract of S mutans in Freund's incomplete adjuvant were compared with a vaccine of a noncariogenic Streptococcus CHT, the adjuvant alone, and a sham immunized group. Sequential analysis of complement fixing, hemagglutinating and precipitating antibodies to the cell wall, and extracellular culture extract have shown that a significant reduction in smooth surface and fissure caries resulted from immunization with the S mutans vaccines, if antibodies reached an optimum level before caries development started. Protection was not elicited by the culture extract of S mutans or the noncariogenic Streptococcus CHT vaccines. A recently developed bacteriological sampling technique of crevicular fluid, plaque, and saliva showed that caries reduction in immunized animals was associated with a significantly decreased percentage of S mutans in crevicular fluid. Immunochemical studies showed IgG and IgM classes of antibodies in serum and secretory IgA antibodies in saliva, but it appears that reduction in caries was best associated with serum IgG antibodies to the culture extract of S mutans. The humoral and cellular mechanisms involved in the immunologic control of caries are discussed in terms of a central afferent mechanism required for antigen processing and cellular proliferation, and two peripheral effector mechanisms that function in the crevicular and salivary domains.

Tolerance to amphetamine in two species (rat and guinea pig) that metabolize it differently

It has been proposed that p-hydroxynorephedrine, a metabolite of amphetamine, is responsible for the tolerance that occurs to this drug. To test this idea, the development of tolerance to amphetamine has been examined in two species, the rat and the guinea pig, the former of which produces p-hydroxynorephedrine from amphetamine while the latter does not. In both species, tolerance develops to the anorectic and hyperthermic actions of amphetamine, and similar changes in the pattern of behavioural stimulation are seen.

Insulin adsorbance to polyvinylchloride surfaces with implications for constant-infusion therapy

Because of the current interest in constant intravenous infusions of insulin for hyperglycemic conditions, we have re-examined the problem of insulin adsorption to the solid surfaces of commonly used infusion sets. Using both labeled and unlabeled insulin, we have compared solutions with and without albumin through various methods of delivery. An infusion system incorporating a 50-ml. wash-out with a solution of 25 U. regular insulin in 500 ml. normal saline permits delivery of at least 75 per cent of expected insulin for the first 50 ml. of the infusion and 100 per cent thereafter. After the first 20 ml. of the infusion, the per cent insulin recovered from the system is identical to that observed when albumin was added to the infusion solution at a concentration of 1.25 gm. per cent. From these date, we conclude that if an insulin concentration of at least 25 U./500 ml. is used, and if 50 cc. is washed through the infusion apparatus before treatment of a hyperglycemic patient is instituted, no extra protein additives are necessary.

Highly elevated content of free myo-inositol in the cerebrospinal fluid of neonates

Free myo-inositol in cerebrospinal fluid was determined in 60 babies aged from newborn to 12 months. In the neonates, a high inositol concentration was found (18-81 mg/100 ml). With increasing age, the values gradually decreased. The finding is discussed in relation to the maturation processes in central nervous tissue.

Ontogeny of immunity in man

We have reviewed selected aspects of recent findings in the ontogeny of immunity in man. For obvious reasons, constraints placed on experimental work with human subjects, albeit deceased foetuses, limit the work to in vitro studies. Nevertheless, a number of novel and important concepts have emerged. First, as in lower animals, lymphoid development of the foetal thymus in general precedes the development of immunocompetence in peripheral lymphoid tissues. A striking exception to this rule is the finding of cells in early foetal liver which respond to allogeneic cells in the mixed lymphocyte culture some weeks before lymphoid organization of the thymus. In addition, the response of foetal cells to allogeneic cells in the mixed lymphocyte reaction (MLR) precedes the response to phytohaemagglutinin (PHA), a stimulant with relative T cell specificity. The use of markers for T cells to map the emergence of this class of lymphocytes correlates well with various functional attributes of T cells in in vitro culture systems. B cells emerge first in foetal liver at about 9 weeks' gestation, but formation of immunoglobulin by the foetus occurs at very low levels until after birth. There is a suggestion that progression from IgM to IgA synthesis occurs during human foetal lymphoid development. Taken as a whole, these data suggest a rather remarkable and perhaps unexpected degree of cellular and potential humoral immunocompetence at early stages of feotal development in man.

Fitzgerald factor: a hitherto unrecognised coagulation factor

A newly recognised asymptomatic coagulation-factor deficiency is reported in a 71-year-old man. This factor seems to operate at an early stage in the intrinsic coagulation pathway and participates in other Hageman-factor-mediated biological reactions. The patient has an atypical cellular inflammatory response as observed by the skin-window technique.

The effect of growth environment on the chloroform-methanol and alkali-extractable cell wall and cytoplasm lipid levels of Mucor rouxii

The distribution of chloroform-methanol and alkali-extractable lipids in the cell walls of aerobically grown filamentous cells from Mucor rouxii has been determined. The results have been compared with the corresponding lipid composition of yeast-like cells from M. rouxii, which can be produced in two ways: by growth under anaerobic conditions and by aerobic growth in the presence of 0.22% phenethyl alcohol (PEA). It was observed that in most cases the crude cytoplasmic fraction contained higher levels of several lipids (i.e., squalene, sterols, triterpenes, and fatty acids) than did the corresponding cell walls. The cell walls did, however, contain both "free" (chloroform-methanol extractable) and "bound" (alkali extractable) lipids although the relative amounts were markedly dependent on the cell growth environment. The aerobically grown filamentous cell walls contained higher levels of squalene, sterols, triterpenes, and fatty acids than did aerobically grown yeast-like PEA-induced cell walls and there was also considerable variation in the "free"/"bound" ratios of the various lipid components. The lipid levels in both the cell walls and cytoplasm of the anaerobically grown cells were considerably lower than those of the cells grown under aerobic conditions. In addition, the differences in the growth environment were also reflected in the compositions of the individual lipid fractions from both the cell wall and the cytoplasm fraction.

Intercostal nerve conduction and posterior rhizotomy in the diagnosis and treatment of thoracic radiculopathy

Intercostal nerve conduction study has proved to be an accurate technique in diagnosis of thoracic radiculopathy in 161 patients, 80 of whom had subsequent posterior rhizotomy with relief of pain in 81% of those undergoing surgery. The only significant complication of intercostal nerve conduction study is an 8·8% incidence of pneumothorax.

Biliary excretion of amphetamine and methamphetamine in the rat

1. (14)C-labelled amphetamine and methamphetamine were injected into rats cannulated at the bile duct under thiopentone anaesthesia and the output of their metabolites in urine and bile was determined. 2. With amphetamine, 69% of the (14)C was excreted in the urine and 16% in the bile in 24h. The main metabolite in bile was the glucuronide of 4-hydroxyamphetamine. The output of unchanged amphetamine was much greater in cannulated rats than in intact rats. 3. With methamphetamine, 54% of the (14)C appeared in the urine and 18% in the bile. The main metabolite in the bile was the glucuronide of 4-hydroxynorephedrine. The output of amphetamine, a metabolite of methamphetamine, was much greater in cannulated rats than in intact rats. 4. Evidence has been obtained for the enterohepatic circulation of certain amphetamine and methamphetamine metabolites in the rat. 5. Thiopentone anaesthesia appeared to inhibit the ring hydroxylation of amphetamine administered as such or formed as a metabolite of methamphetamine.

Norephedrines as metabolites of ( 14 C)amphetamine in urine in man

(+/-)-[(14)C]Amphetamine sulphate (20mg) was administered orally to each of two human male subjects, and 80-85% of the (14)C was excreted in the urine in 2 days. The metabolites in the first day's urine were examined quantitatively. Apart from the metabolites previously described (Dring et al., 1970), norephedrine (2.2 and 2.6% of dose in the two subjects respectively) and 4-hydroxynorephedrine (0.3 and 0.4% of dose in the two subjects respectively) were also found.

Metabolism of ( 14 C)methamphetamine in man, the guinea pig and the rat

1. The metabolites of (+/-)-2-methylamino-1-phenyl[1-(14)C]propane ([(14)C]methamphetamine) in urine were examined in man, rat and guinea pig. 2. In two male human subjects receiving the drug orally (20mg per person) about 90% of the (14)C was excreted in the urine in 4 days. The urine of the first day was examined for metabolites, and the main metabolites were the unchanged drug (22% of the dose) and 4-hydroxymethamphetamine (15%). Minor metabolites were hippuric acid, norephedrine, 4-hydroxyamphetamine, 4-hydroxynorephedrine and an acid-labile precursor of benzyl methyl ketone. 3. In the rat some 82% of the dose of (14)C (45mg/kg) was excreted in the urine and 2-3% in the faeces in 3-4 days. In 2 days the main metabolites in the urine were 4-hydroxymethamphetamine (31% of dose), 4-hydroxynorephedrine (16%) and unchanged drug (11%). Minor metabolites were amphetamine, 4-hydroxyamphetamine and benzoic acid. 4. The guinea pig was injected intraperitoneally with the drug at two doses, 10 and 45mg/kg. In both cases nearly 90% of the (14)C was excreted, mainly in the urine after the lower dose, but in the urine (69%) and faeces (18%) after the higher dose. The main metabolites in the guinea pig were benzoic acid and its conjugates. Minor metabolites were unchanged drug, amphetamine, norephedrine, an acid-labile precursor of benzyl methyl ketone and an unknown weakly acidic metabolite. The output of norephedrine was dose-dependent, being about 19% on the higher dose and about 1% on the lower dose. 5. Marked species differences in the metabolism of methamphetamine were observed. The main reaction in the rat was aromatic hydroxylation, in the guinea pig demethylation and deamination, whereas in man much of the drug, possibly one-half, was excreted unchanged.