Separation of female Psychodopygus wellcomei and P. complexus (Diptera: Psychodidae) by cuticular hydrocarbon analysis

Psychodopygus wellcomei (Diptera: Psychodidae), vector of Leishmania braziliensis braziliensis - causative agent of cutaneous leishmaniasis in Brazil, cannot be distinguished from sympatric P. complexus either by morphometrics or isoenzyme profiles. We report here the use of cuticular hydrocarbon analysis in the successful separation of individual female P. wellcomei and P. complexus. This technique involves the use of gas liquid chromatography and discriminant function analysis.

Can the prevalence of disease risk factors be assessed from general practice records?

The result of an audit of the recording of smoking habit, alcohol consumption, blood pressure level, diet, exercise, height, weight, and occupation in patients in five general practices is reported. This audit was the first phase of a study to assess the feasibility of the exchange of information between general practice and a district health authority. The frequency with which each item was recorded varied from 3% (exercise) to 65% (blood pressure) in a five year period. The sample of patients upon whom a recording had been made was shown to be unrepresentative of the practice population: this presents a difficulty in using general practice records to estimate the prevalence of risk factors for disease in the community.

The affinity of norgestimate for uterine progestogen receptors and its direct action on the uterus

Norgestimate is a new orally active progestational agent. Studies were conducted to demonstrate that norgestimate is active pharmacologically without requiring biotransformation to an active metabolite. In in vitro studies, norgestimate exhibited a relatively high affinity for the rabbit uterine progestogen receptor. To demonstrate that norgestimate was not being degraded to a biologically active entity, which was binding to receptor sites in the cytosol preparation, the stability of 14C-norgestimate in the preparation was determined. Following the incubation of 14C-norgestimate with the cytosol fraction used in the receptor assay, the labeled material was extracted and analyzed by reverse phase high performance liquid chromatography. 14C-Norgestimate was recovered from these incubation mixtures, confirming that norgestimate was available to bind to the progestogen receptor. In in vivo studies, norgestimate stimulated the endometrium in immature rabbits when applied directly to the uterus, again suggesting that bio-transformation to an active metabolite is not required for expression of norgestimate's pharmacological activity. These in vitro and in vivo studies, when considered with previously reported studies, show that norgestimate is a unique progestogen.

Effect of androgens and gonadotropins on progesterone secretion of chicken granulosa cells

A culture system has been used to study the effect of PMSG in vivo pretreatment and androgens on the in vitro secretion of progesterone from avian granulosa cells. PMSG in vivo pretreated cells secreted greater amounts of progesterone than did cells obtained from untreated hens. Testosterone and 5-alpha-dihydrotestosterone significantly increased basal progesterone secretion in PMSG pretreated cells as well as in granulosa cells harvested from non-treated hens. Testosterone or 5 alpha-dihydrotestosterone in combination with FSH or LH were additive and never resulted in a synergistic stimulation of progesterone secretion.

Inhibin activity and steroid hormone levels in ovarian extracts and ovarian vein plasma of female monkeys during postnatal development

Inhibin activity, follicle-stimulating hormone (FSH)-suppressing substance, estrogen, progesterone, and androstenedione were measured in charcoal-treated ovarian tissue and ovarian venous and peripheral blood of eight rhesus monkeys ranging from 12 to 48 months of age. All of the monkeys demonstrated inhibin activity in ovarian tissue, which, if expressed per milligram protein, was relatively constant throughout development. However, if the activity was expressed per ovary, the amount of ovarian FSH-suppressing substance increased between 26 and 48 months; it was present in detectable amounts in ovarian venous blood only in one 26-month-old monkey. Detectable levels of estrogen were present in ovarian venous blood of the 26-month-old and the 48-month-old monkeys but not in the younger monkeys. It is possible that the secretion of inhibin activity may be in part responsible for low levels of serum FSH observed prior to puberty, because it has been observed by others that bilateral ovariectomy in the prepubertal monkey can result in a rise in FSH and that administration of charcoal-treated ovarian follicular fluid can suppress serum FSH in castrated prepubertal and adult rhesus monkeys.

Comparative effect of estriol and equine conjugated estrogens on the uterus and the vagina

Estriol has been reported to act selectively on the vagina and cervix without causing endometrial proliferations. Studies comparing this effect of estriol to that of equine conjugated estrogens after intravaginal administration have not been reported. In this study, intravaginally administered Ortho- Gynest which contains estriol, and Premarin which contains equine conjugated estrogens, were evaluated for their ability to stimulate vaginal maturation and uterine growth in rats. Approximately 15 times more conjugated estrogens than estriol was needed to induce the same degree of vaginal cornification in castrated rats. In contrast, estriol was less potent than the conjugated estrogens in causing uterine growth in immature rats after subcutaneous administration in sesame oil and in mature rats after intravaginal administration in cream preparations. In studies evaluating the vaginal irritation potential of estriol vaginal cream, the irritation exhibited by treated rabbits was found to be comparable to that of sham-treated control rabbits. Estriol was well-tolerated in an oral acute safety study in rats.

Potency and activity variation of LHRH analogs in different models and species

The LHRH agonist [D-His(Bzl)6, Pro9-NHEt]LHRH was estimated to be 3.4, 4.4 and 9.2 times more potent than LHRH as a stimulator of ovulation in Nembutal-anesthetized, androgen-sterilized and diestrus rats, respectively; and 57 times more potent than LHRH as a stimulator of uterine growth in immature mice. Higher doses of agonist were required to induce ovulation in diestrus hamsters and mice than were needed in diestrus rats. Rats and hamsters also exhibited different sensitivities to an antagonist of LHRH. The LHRH antagonist [N-Ac delta 3-Pro1, D-pF-Phe2,D-Trp3,6]LHRH was active but higher doses were required to inhibit ovulation in hamsters than were needed in rats. In addition, treatment at 1500 hr on the day of proestrus in rats, in contrast to treatment at 1000 hr in hamsters, caused the greatest inhibition of ovulation. It is clear from these data, that the estimated in vivo potencies of analogs of LHRH are greatly influenced by species and animal model, as well as route of administration and biopharmaceutic factors previously reported.

Dystrophic mutation (dy2J) affecting regulation of lactate dehydrogenase (LDH) and pyruvate kinase (PK) in C57BL/6J mice

The genotype difference (dystrophic vs nondystrophic) in the LDH isozymes is observed in kidney. These differences are evident only at birth and at early developmental stages (before the expression of dystrophic symptoms). The tissue specific genotype differences for PK are limited to the thigh muscle (M form) and heart (L form), after the onset of the condition. These differences may reflect the pleiotropic effect of the dy2J locus during the temporal regulation of these and other enzymes implicated in muscular dystrophy (MD).

Flat small intestinal mucosa and autoantibodies against the gut epithelium

A male infant, aged 1 year 3 months, was admitted to the hospital with protracted diarrhoea, vomiting, and weight loss. The diarrhoea and vomiting coincided with an outbreak of acute diarrhoea and vomiting affecting other family members. Biopsy showed a flat small intestinal mucosa which did not respond to a diet free of gluten, cow's milk, and eggs, or during 8 weeks of intravenous alimentation. Steroids were given, and courses of nalcrom and later cimetidine, but these did not produce any significant improvement. A rare IgG autoantibody specific for gut epithelium was found, which, when present, was associated with a cytological abnormality of crypt enteroblasts. The autoantibody disappeared after treatment with cyclophosphamide, and the cytological abnormality subsequently diminished. However, the mucosa remained severely abnormal and has been so for 23 months. It is possible that an autoimmune reaction against the patient's small intestinal mucosa has led to persistence of the enteropathy.

The effect of porcine follicular fluid on ovulation, mating and pregnancy in the rat

We have examined the effects of charcoal-treated, greater than 10,000 MW porcine follicular fluid (PFF retentate) treatment on ovulation, cyclicity, mating and pregnancy in the rat. Rats treated i.p. with PFF retentate twice on the day of metestrus and once on the day of diestrus exhibited a dose-related reduction in the mean number of ova when oviducts were checked on the afternoon of expected estrus. However, oviducts checked on the morning of expected metestrus contained a normal number of ova. To study the effects of PFF retentate on cyclicity, mating and subsequent pregnancy, rats were treated (0.2 ml, i.p.) two, three or four times a day beginning on the day of metestrus until proestrus cytology was exhibited. PFF retentate treatment resulted in a dose-related delay in the appearance of proestrus cytology and a reduction in the number of embryonic implants following cohabitation with males on the night of proestrus. However, PFF retentate had no effect on the number of implants, when given post-coitally. These results show that administration of PFF retentate to female rats delays ovulation, alters the estrous cycle and reduces the mean number of embryonic implants in a dose-related manner.

Treatment of life-threatening digitalis intoxication with digoxin-specific Fab antibody fragments: experience in 26 cases

Purified Fab fragments of digoxin-specific antibodies obtained from sheep were used to treat 26 patients with advanced, life-threatening digoxin (23 cases) or digitoxin (3 cases) toxicity. These patients had advanced cardiac arrhythmias, and in some cases hyperkalemia, which were resistant to conventional treatment. All patients had an initial favorable response to doses of Fab fragments calculated (in most cases) to be equivalent, on a molar basis, to the amount of cardiac glycoside in the patient's body. In four patients treated after prolonged hypotension and low cardiac output, death ensued from cerebral or myocardial hypoperfusion. In one case the available Fab fragment supply was inadequate to reverse a massive suicidal ingestion of digoxin, and the patient died after recurrent ventricular arrhythmias. In the remaining 21 patients, cardiac rhythm disturbances and hyperkalemia were rapidly reversed, and full recovery ensued. There were no adverse reactions to the treatment. We conclude that the use of purified digoxin-specific Fab fragments is a safe and effective means to reverse advanced, life-threatening digitalis intoxication.

Analysis of phosphate in serum with the phosphate redox electrode system

A phosphate redox electrode system (PRES) was designed, constructed, and evaluated for analysis of inorganic phosphate in serum. This system is based on the observed phosphate ion potential of a chemically treated iron wire in a turbulent flow-through cell at constant oxygen tension. We analyzed 110 clinical samples by this technique and with the Technicon SMAC. Of the specimens analyzed, 32% contained abnormal phosphate concentrations. Each was assayed two to four times with the PRES and once with the SMAC. The PRES assay rate was 60 samples/h. Mean phosphorus concentrations (and SEM) were: PRES, range of values for replicate data sets, 30.5-31.0 (0.5-1.1) mg/L; SMAC, 30.8 (1.0) mg/L. Results for the PRES (y) correlated well with those by the SMAC: r = 0.968 to 0.980, estimated slope = 0.99 to 1.03, and estimated intercept = -1.1 to 0.1 mg/L. Differences in results by the two methods were not statistically significant.

Analysis of phosphate in serum with the phosphate redox electrode system

A phosphate redox electrode system (PRES) was designed, constructed, and evaluated for analysis of inorganic phosphate in serum. This system is based on the observed phosphate ion potential of a chemically treated iron wire in a turbulent flow-through cell at constant oxygen tension. We analyzed 110 clinical samples by this technique and with the Technicon SMAC. Of the specimens analyzed, 32% contained abnormal phosphate concentrations. Each was assayed two to four times with the PRES and once with the SMAC. The PRES assay rate was 60 samples/h. Mean phosphorus concentrations (and SEM) were: PRES, range of values for replicate data sets, 30.5-31.0 (0.5-1.1) mg/L; SMAC, 30.8 (1.0) mg/L. Results for the PRES (y) correlated well with those by the SMAC: r = 0.968 to 0.980, estimated slope = 0.99 to 1.03, and estimated intercept = -1.1 to 0.1 mg/L. Differences in results by the two methods were not statistically significant.

Traveller's diarrhoea with a vengeance in children of UK immigrants visiting their parental homeland

Six healthy children, born in the UK, travelled to their parental homeland and developed a severe form of traveller's diarrhoea. This was characterised by rapid loss of weight and chronic diarrhoea. On return to this country, investigation in 5 of them showed an abnormal, small intestinal mucosa. There was a high incidence of pathogens and potential pathogens found in stools and duodenal juice. Immunodeficiency was found in 2 of them. Small intestinal mucosal damage related to gut infection in previously well children appears to be of cardinal importance in the interaction between chronic diarrhoea and malnutrition. This observation may point the way to future research into the primary role of gut infection in the initiation of the cycle of malnutrition and chronic diarrhoea in developing communities.

Cows' milk-sensitive enteropathy

Serial small intestinal biopsies related to withdrawal and challenge with cows' milk are described in 5 infants with cows' milk protein intolerenace. On the basis of these serial observations the existence of a cows' milk-sensitive enteropathy in infancy is clearly established. The cows' milk-sensitive mucosal lesion varied in its severity ranging from a partly flat mucosa to a mild degree of partial villous atrophy. Intraepithelial lymphocyte counts rose after a positive milk challenge, but on only one occasion to a level outside the normal range. The technique of serial biopsies related to dietary milk enables a firm diagnosis of cows' milk intolerance to be made upon the basis of a single milk challenge. Clinically this appears to be a temporary condition which disappears by the age of 2 years.

Purification and properties of Escherichia coli dihydrofolate reductase

Dihydrofolate reductase has been purified 40-fold to apparent homogeneity from a trimethoprim-resistant strain of Escherichia coli (RT 500) using a procedure that includes methotrexate affinity column chromatography. Determinations of the molecular weight of the enzyme based on its amino acid composition, sedimentation velocity, and sodium dodecyl sulfate gel electrophoresis gave values of 17680, 17470 and 18300, respectively. An aggregated form of the enzyme with a low specific activity can be separated from the monomer by gel filtration; treatment of the aggregate with mercaptoethanol or dithiothreitol results in an increase in enzymic activity and a regeneration of the monomer. Also, multiple molecular forms of the monomer have been detected by polyacrylamide gel electrophoresis. The unresolved enzyme exhibits two pH optima (pH 4.5 and pH 7.0) with dihydrofolate as a substrate. Highest activities are observed in buffers containing large organic cations. In 100 mM imidazolium chloride (pH 7), the specific activity is 47 mumol of dihydrofolate reduced per min per mg at 30 degrees. Folic acid also serves as a substrate with a single pH optimum of pH 4.5. At this pH the Km for folate is 16 muM, and the Vmax is 1/1000 of the rate observed with dihydrofolate as the substrate. Monovalent cations (Na+, K+, Rb+, and Cs+) inhibit dihydrofolate reductase; at a given ionic strength the degree of inhibition is a function of the ionic radius of the cation. Divalent cations are more potent inhibitors; the I50 of BaCl2 is 250 muM, as compared to 125 mM for KCl. Anions neither inhibit nor activate the enzyme.

Mechanics of sphincter action. Studies on the lower esophageal sphincter

The purpose of this study was to evaluate the mechanical factors involved in the genesis of lower esophageal sphincter pressure. We determined the relationship between intraluminal pressure and inside diameter, estimated the ratio between the wall thickness to inside radius, and calculated the tension in the wall of the lower esophageal sphincter as a function of the inside diameter. Various degrees of circumferential stretch were applied by introducing probes of different diameters in the rat lower esophageal sphincter in vivo. The intraluminal pressure produced by the lower esophageal sphincter around each probe was measured and pressure-diameter curves were constructed during (a) resting state, (b) contraction produced by electrical stimulation, and (c) relaxation produced by esophageal distension. The intraluminal pressure at an inside diameter of 0.5 mm was similar to that at inside diameter of 3.2 mm. This was true for the sphincter at rest as well as upon electrical stimulation. The pressure diameter curve, however, was sigmoid in shape; at first it showed a decline and then an increase followed by decline in pressure again with increasing diameters. The ratio of wall thickness to inside radius or the magnification factor varied with inside diameters as expected and this ratio increased steeply at small inside diameters. The tension diameter curves of the sphincter muscle showed that optimal tension development occurred not near sphincter closure but at a much wider diameter of 3.2 mm and that this muscle developed tension even at small luminal diameters. This behavior of the sphincter muscle ensures effective intraluminal pressure over a wide range of luminal diameters.