The isolated anterior stomach of larval mosquitoes (Aedes aegypti): voltage-clamp measurements with a tubular epithelium

The anterior stomach of larval Aedes aegypti was isolated and perfused via two pipettes. For transepithelial voltage (V(te)) measurement, the inflow pipette and the bath were connected via agar bridges to calomel electrodes. For voltage-clamping, the lumen of the tissue contained an Ag/AgCl wire held by the outflow pipette, and the preparation was placed in a bath within a spiral of Ag/AgCl wire. After equilibrating the tissue in mosquito saline on both sides, a V(te) of -8+/-1 mV was measured (+/-S.E.M., N=32). Current-voltage curves (+/-100 mV) demonstrated ohmic behaviour of the epithelium. Short-circuiting resulted in a current (I(sc)) of 103+/-16 microA cm(-2) and a mean transepithelial conductance (G(te)) of 11.8+/-1.3 mS cm(-2) (+/-S.E.M., N=32). A Yonath-Civan plot of G(te) of individual preparations over the corresponding I(sc) resulted in a straight line (r(2)=0.8422), indicating that the difference in I(sc) of individual preparations is mainly based on different transcellular conductances (G(c)). This analysis allowed to estimate the mean leak conductance (G(l) approximately 3.9 mS cm(-2)) and the mean transcellular electromotive force (E(c) approximately 13 mV). After administering 0.2 micromol L(-1) serotonin, I(sc) and G(te) significantly increased, to 457+/-49 microA cm(-2) and to 21.3+/-2.3 mS cm(-2) (+/-S.E.M., N=31, P<0.05), respectively. The Yonath-Civan plot after serotonin resulted again in a straight line (r(2)=0.8219), indicating a mean G(l) of about 1 mS cm(-2) and a mean E(c) of about 22 mV. Dinitrophenol (2.5 mmol L(-1)) almost abolished I(sc) and significantly reduced G(te) (N=6). Concanamycin A (100 micromol L(-1)) reduced I(sc) by more than 90% without significantly affecting G(te).     

Nuclear magnetic resonance of 23Na ions interacting with the gramicidin channel.

Basic nuclear magnetic resonance (NMR) features of 23Na ions bound to the gramicidin channel (packaged into lecithin liposomes) were studied. The first binding constant K1 of Na+ was not significantly dependent on channel models employed. With the two-identical-site model (Model I), K1 was 13.7 (+/- 1.4) molal-1 (in the activity basis) at 25 degrees C; when the binding of a third ion was included (Model II), it was 13.0 (+/- 2.0) molal-1. The second binding constant K2 was model dependent; it was 1.6 (+/- 0.2) and 3-4 molal-1 for Models I and II, respectively. The rate constants, k-1 and k-2, of Na+ for exit from singly and doubly loaded channels, respectively, were 8 X 10(5) s-1 less than or equal to k-1 less than or equal to 3 X 10(6) s-1 and 8 X 10(5) s-1 less than or equal to k-2 less than or equal to 1.0 X 10(7) s-1 at 25 degrees C; the lower bound represents a rough approximation of k-1. The ratio k-2/k-1 was greater than one and did not greatly exceed 20. From the competition experiment, K1 of T1+ was 5.7 (+/- 0.6) X 10(2) molal-1. The longitudinal relaxation time T1 of bound 23Na in the state of single occupancy (T 1B sing) was virtually independent of models, 0.56 (+/- 0.03) and 0.55 (+/- 0.04) ms at 25 degrees C for Models I and II, respectively. For the state of double occupancy, T1 of bound 23Na (T 1B doub) was model dependent: 0.27 (+/- 0.01) and 0.4-0.6 ms for Models I and II. The correlation time tau c of bound 23Na was 2.2 (+/- 0.2) ns at 25 degrees C for single occupancy; tau c for double occupancy was not significantly different from this value. The estimated tau c was found to involve no appreciable contribution of the exchange of 23Na between the channel and the bulk solution. Thé quadrupole coupling constant chi was 1.0 (+/- 0.1) MHz for 23Na in single occupancy; chi for double occupancy was 0.9-1.4 MHz, depending on models. A lower bound of the average quadrupole coupling constant chi alpha was 0.13-0.26 MHz at 25 degrees C for 23Na in single occupancy; this value represents a rough approximation of chi alpha at this temperature. An argument based on the estimated chi alpha and the known conformation of the gramicidin channel suggests that the binding site is a small domain near the channel end.(ABSTRACT TRUNCATED AT 400 WORDS)     

Reduced prostaglandin E2 (PGE2) receptors on atopic T lymphocytes

We have recently demonstrated that atopic T lymphocytes have decreased sensitivity to prostaglandin E2 (PGE2). In order to determine whether this decreased sensitivity was reflected at the receptor level, we have employed a radioligand binding assay utilizing [3H]PGE2. We have demonstrated a single specific reversible binding site for [3H]PGE2 on normal T cells (N = 10) with a mean KD (+/-SD) of 32.2 (+/-25.0) nM, a binding capacity of 20.2 (+/-13.0) pM, and a mean of 1004 (+/-118) receptors per cell. Atopic T cells (N = 10) were also found to have a single specific binding site for [3H]PGE2 with a mean KD of 24.9 (+/-17.8) nM, a binding capacity of 7.1 (+/-10.1) pM, and a mean of 372 (+/-61) receptors per cell. These radioligand binding studies were correlated with functional studies in the same subjects. Phytohemagglutinin-stimulated protein synthesis ([3H]leucine uptake) was suppressed in a dose-dependent fashion by PGE2 (10(-6)-10(-12) M). The maximal effect of PGE2 on normal T cells was 10(-6) M PGE2 with an IC50 of 10(-12) M. Atopic T cells responded quantitatively less than normal T cells to PGE2. Further, the maximum suppression of protein synthesis by PGE2 occurred at 10(-6) M with an IC50 of 10(-10) to 10(-11) M. These studies suggest that part of the decreased sensitivity of atopic T cells to PGE2 may result from a reduction in PGE2 binding sites.     

Selective effects of adenosine receptor agonists upon coronary resistance and heart rate in isolated working rabbit hearts

Dose dependent changes in heart rate (HR) and coronary resistance (CR) were determined for adenosine, 5'-N-ethylcarboxamide adenosine (NECA) and l-N6-phenylisopropyladenosine (l-PIA) over a dose range of 1 X 10(-9) to 1 x 10(-5) M. Changes in CR were determined under controlled metabolic demand conditions (constant mean aortic pressure, constant mean left atrial pressure, and constant HR). Decreases in HR were determined by allowing the paced hearts to beat spontaneously between doses for 15 seconds. Adenosine significantly decreased CR and HR at greater than or equal to 1 X 10(-5) M. NECA significantly decreased both CR and HR at greater than or equal to 3 X 10(-8) M. l-PIA significantly decreased HR at greater than or equal to 3 X 10(-8) M; however a dose at greater than or equal to 3 X 10(-6) M was required to significantly decrease CR. These results provide evidence that the coronary vasodilator action of adenosine may primarily be mediated by A2 receptors. Furthermore, the data are in support of previous observations that the bradycardic action of adenosine is principally mediated via A1 receptors.     

Metabolism of sulfur-containing amino acids by pregnant merino ewes

The availability and utilization of cystine and methionine were measured in single-bearing Merino ewes on three occasions, approximately 90, 110 and 130 days after mating, and the effects on these traits of sulfur amino acids (SAA) infused into the abomasum were also measured. Two levels of SAA were infused containing 0.5 or 1.0 g day-1 organic sulfur with DL-methionine contributing two-thirds and L-cystine one-third of the supplementary sulfur. The quantity of the diet offered was increased at each occasion so as to maintain maternal liveweight. The rates of irreversible loss of both cystine and methionine from plasma increased as pregnancy advanced, but the ratios between the rates of irreversible loss and intake of digestible organic matter (DOMI) did not vary with stage of pregnancy. The average daily rates of irreversible loss of cystine and methionine by the ewes consuming the diet alone were 13.6 and 119 mmol kg-1 DOMI respectively. The average rates of irreversible loss of methionine (Im, mmol h-1) and of cystine (Ic, mmol h-1) were both linearly (P less than 0.05) related to the rate of infusion of organic sulfur into the abomasum (s, g day-1): Im = 2.44 (+/- 0.33) s + 1.28 (+/- 0.13); and Ic = 0.16 (+/- 0.02) s + 0.30 (+/- 0.01). Five per cent of the rate of irreversible loss of cystine arose from trans-sulfuration of methionine by ewes consuming the ration only, but greater percentages (14 and 22%) were observed when the ration was supplemented with SAA (P less than 0.05). These transfer quotients were not influenced by stage of pregnancy. The stage of pregnancy did not influence the concentration of cystine or methionine in the plasma, but the abomasal infusions of SAA significantly increased the concentration of both SAA. The ewes consuming the basal diet were in positive balance for both nitrogen and sulfur. The retention of nitrogen did not vary with stage of pregnancy (average (s.e.), 5.8 (0.9) g day-1), but that of sulfur increased from 0.6 to 1.0 and 1.3 g day-1 in periods 1, 2 and 3, respectively (P less than 0.05). The retentions of nitrogen (N, g day-1) and of sulfur (S, g day-1) were linearly and significantly related to the rate of infusion of organic sulfur into the abomasum (s, g day-1): N = 2.7 (+/- 0.7)s + 4.4 (+/- 0.3); and S = 0.49 (+/- 0.03)s + 0.72 (+/- 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)     

Initial results and long-term clinical follow-up of an amorphous hydrogenated silicon-carbide-coated stent in daily practice

The hemocompatibility and biocompatibility of a stent are determined by the physical and electrochemical properties of the stent surface. The aim of this study was to determine the feasibility, safety and efficacy of implantation of a stent coated with silicon carbide. Baseline characteristics were collected prospectively. The occurrence of cardiac adverse events and the angina score were assessed at clinical follow-up. A total of 193 Tensum stents were implanted in 174 patients. In hospital, one patient experienced stent thrombosis and in 6% of the patients a creatinine kinase elevation to 240 U/l or more occurred. Long-term follow-up was performed in 172 patients, with a mean follow-up of 454 +/- 181 days. Ninety-seven per cent were still alive, 15% had undergone target-vessel revascularization, and 2% had angiographic restenosis and were treated with medication only. Seventy-one per cent of the patients were free of anginal complaints, and 20% had anginal complaints in Canadian Cardiac Society class I or II. The Tensum coronary stent showed to be a safe and efficacious device in this study, with a high primary success rate and favorable long-term clinical followup.     

Contamination of fox hair with eggs of Toxocara canis

Eighty-seven red foxes were investigated for the presence of Toxocara eggs on a sample of their hair from the peri-anal region. The worm burden of Toxocara in each fox intestine was also assessed and the relationship between eggs on the hair and worms in the intestine explored. Twenty-eight per cent of the foxes were found to have Toxocara eggs on their hair, with an average of 1.31 +/- 3.21 eggs per gram of hair (+/- SD). Sixty-one per cent of foxes harboured Toxocara worms within their intestines, with a mean worm burden (+/- SD) of 4 +/- 8. Host age and sex did not significantly influence the observed eggs on the hair or the worm burden. No significant correlation was found between the numbers of eggs on the hair and the worm burden within the intestine. These data collected from foxes are explored in the context of data from stray dogs and the possible epidemiological differences are discussed.     

Synchronous exocytosis in Paramecium cells. IV. Polyamino compounds as potent trigger agents for repeatable trigger-redocking cycles

We found that different polyamino compounds trigger the instantaneous and simultaneous release of trichocysts from Paramecium tetraurelia cells (monoxenically bacterized cultures), provided amino groups are spaced in intervals of approximately 1.0 nm; in this case even diamines or oligopeptides exert some trigger effect. The most potent trigger agent found was aminoethyldextran (AED, MW = 40 kDa) which was used mainly as a derivative with 40 -NH2/molecule. A maximal response (strain K401) was achieved at 1.38 X 10(-6) M, a half maximal response at 1.08 X 10(-6) M. AED acts by a dual effect, i.e., not only by statistically properly spaced amino groups but also by some additional effect of the dextran molecule, since this greatly enhances the effect of oligoamines, although it exerts no trigger effect per se. From a total of approximately 1120 or approximately 1230 trichocysts per cell (strain K401 or 7S) approximately 95% are releasable by AED. In these strains the number of non-releasable trichocysts corresponds closely to the number of undocked trichocysts floating in the cytoplasm, so that practically all trichocysts which are docked to the cell membrane, can be released. (We also analysed different mutant strains for their response to AED.) Massive trichocyst release does not impair cell viability or culture growth, and multiple release-redocking cycles can be performed; up to 5 trigger-docking cycles were tested with individual cells in 12 h intervals. AED-triggered exocytosis requires a free extracellular [Ca2+] of greater than or equal to 10(-5) M; it is inhibited by EGTA (ethyleneglycol-bis(beta-aminoethyl ether)-N,N'-tetraacetate), by a short pH 5.5 shock or by neomycin at 10(-5) M concentration.(ABSTRACT TRUNCATED AT 250 WORDS)     

125I]-Bolton-Hunter scyliorhinin II: a novel, selective radioligand for the tachykinin NK3 receptor in rat brain

The cyclic tachykinin scyliorhinin II (SCYII) has high affinity for the [neurokinin B (NKB)-preferring] NK3 receptor. SCYII was iodinated using [125I]-Bolton-Hunter reagent and the product BHSCYII purified using reverse phase HPLC. In rat brain membranes, binding of BHSCYII and of the relatively unselective radioligand [125I]-Bolton-Hunter eledoisin (BHELE) was saturable, reversible and to an NK3 site. In competition studies, the rank order of potency in inhibiting binding of BHSCYII and BHELE was: SCYII greater than or equal to [MePhe7]-NKB approximately senktide greater than NKB greater than or equal to kassinin greater than or equal to eledoisin greater than [Pro7]-NKB greater than neurokinin A greater than neuropeptide K greater than or equal to substance P greater than [Sar9, Met(O2)11]-substance P. In "cold" saturation experiments, binding of BHELE occurred to a single class of high affinity sites (KD, 18.6 +/- 0.91 nM). Binding of BHSCYII was of greater affinity than for BHELE and could be resolved into a high (KD, 1.33 +/- 0.98 nM; 27% of sites) and low affinity (KD, 9.84 +/- 2.75; 73% of sites) component. The total number of binding sites was similar for both radioligands (BHSCYII, 8.27 +/- 0.98; BHELE, 7.94 +/- 0.32 fmol/mg wet weight). In vitro autoradiography in slide-mounted sections of rat brain showed identical binding patterns for both radioligands (100 pM), with dense binding localized predominantly to the cortex, Ammon's horn field 1, premammillary nuclei and interpeduncular nucleus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of plasminogen binding to human capillary and arterial endothelial cells.

Phenotypic diversity of endothelial cells that line the various vascular spaces has been well established. However, it is not known if biochemical differences also exist, particularly in the numbers of receptors for plasma proteins. Equilibrium binding techniques were used to assess potential differences in the binding of 125I-labelled plasminogen to cultured human umbilical arterial endothelial cells and capillary endothelium, as compared with umbilical venous cells. The kinetic behaviour of plasminogen binding to all three types of cells was similar, with optimal binding occurring between 20 and 30 min of incubation. Binding of plasminogen to arterial, capillary, and venous cells was concentration dependent and reversible upon addition to excess unlabelled plasminogen. Scatchard analyses showed that artery, capillary, and venous endothelial cells all possess low affinity sites for plasminogen with Kd values of 0.30 +/- 0.07, 0.40 +/- 0.06, and 0.40 +/- 0.08 microM, respectively. Vein cells also possess an additional higher affinity binding site with a Kd of 0.07 +/- 0.01 microM, exhibiting a 6-fold greater affinity for plasminogen than the lower affinity sites on capillary and arterial endothelial cells. Assuming a stoichiometry of 1:1 for binding, the data indicate that arterial and capillary endothelial cells contain approximately 4.2 (+/- 0.9) x 10(6) and 4.1 (+/- 0.6) x 10(6) plasminogen receptors per cell. Venous cells contain both low and high density binding sites with 6.2 (+/- 0.8) x 10(6) and 12.4 (+/- 2.4) x 10(6) sites per endothelial cell. The presence of a higher affinity site on vein cells, but not on artery or capillary cells, may signal functional differences relating to fibrinolytic activity on the surface of these cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

(Na-K)ATPase activity along the nephrons in normal and adrenalectomized rats measured by quantitative cytochemistry

A cytochemical method was used to measure total, ouabain insensitive and specific (Na-K)ATPase activities along the rat nephron. Enzyme activity was expressed as per cent of mean integrated extinction with reference to a calibrated filter. The lowest mean values of total, ouabain-insensitive, and (Na-K)ATPase activities were found in the proximal convoluted tubule (PCT). In the distal convoluted tubule (DCT), total and ouabain-insensitive activities (77.8 per cent and 45.8 per cent, respectively) were significantly higher than in the medullary thick ascending limb (MAL) (66.0 per cent and 24.6 per cent, respectively). Mean values of (Na-K)ATPase activity were significantly lower in DCT than in MAL (32.0 per cent and 41.3 per cent, respectively). Using Lineweaver-Burk plots, the KM ATP value for total ATPase activity was found to be 2.33, 1.79, and 3.63 mM in DCT, MAL, and PCT respectively. Maximal velocity was lower in PCT than in MAL and DCT. For (Na-K)ATPase, the smallest KM value was found in MAL (0.95 mM) and was 2.73 and 5.71 mM in DCT and PCT respectively. Maximal velocity was the highest in MAL (49.3 per cent), lower in DCT (36.1 per cent) and least in PCT (22.5 per cent). ATPase was measured in the MAL and DCT from rats fed a normal (N-Na+) or a high (Hi-Na+) sodium diet, and from Hi-Na+ rats one week after adrenalectomy (ADX). In the MAL, (Na-K)ATPase tended to be higher in Hi-Na+ than in rats, but was significantly lower in ADX than in Hi-Na+.(ABSTRACT TRUNCATED AT 250 WORDS)     

Antibiotic resistance dynamics of plasma-coagulating staphylococci isolated from patients in 1970-1975]

Resistance of 2345 strains of plasmocoagulating staphylococci isolated from purulent inflammatory foci of surgical patients was studied with respect to the widely used antibiotics by the method of standard paper discs in 1970--1975. It was noted that the cultures resistant to erythromycin and monomycin were more frequent, i.e. from 24.2 +/- 2.5 to 51.4 +/- 3.4 per cent and from 1.0 +/- 0.6 to 28.0 +/- 2.1 per cent respectively, p less than 0.001 in both cases, while the percentage of the strains resistant to benzylpenicillin and tetracycline steadily increased, i.e. from 69.9 +/- 2.4 to 47.0 +/- 2.3 per cent and from 72.8 +/- 2.4 to 28.4 +/- 2.1 per cent respectively, p less than 0.001 in both cases. The number of the resistant cultures to streptomycin and levomycetin slightly changed and was relatively high (about 50 per cent and more). Direct correlation (mean and pronounced) between the amount of levomycetin, tetracycline, erythromycin or monomycin used per citizen of Minsk and the frequency of the strains isolated from the patients to these drugs was noted.     

Proportion of low birth weight infants in Visakhapatnam (India) and its relationship with maternal age, parity and infants survival

The percentage of low birth weight infants (LBWI) weighing less than 2270 g in Visakhapatnam (Andhra Pradesh) is relatively higher (12.8%) than in other parts of India. The frequency of LBWI is high at birth order 1 and 2. Thereafter the curve does not show any consistency although the mean per cent of LBWI is lesser than in birth order 1 and 2. The minimum frequency is at birth order 3. The maternal classes less than or equal to 20-29 years show a gradual decrease in the frequency of LBWI with increasing age. For mothers of greater than or equal to 30-39 years of age a general U-shaped relation is found. The overall distribution of neonatal deaths is bimodal, with a peak at less than 1350 g and at 1810 g.     

3-Hydroxy-3-methylglutaryl coenzyme A reductase activity in cultured fibroblasts from patients with mevalonate kinase deficiency: differential response to lipid supplied by fetal bovine serum in tissue culture medium

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity was measured in extracts of cultured fibroblasts derived from patients with mevalonate kinase deficiency (MKD). For six patients studied, the mean activity of 63.3 +/- 41.1 pmol/min-mg protein (+/- 1 SD, range 37.7-146.2) was significantly higher than the mean value in three control fibroblast lines of 11.1 +/- 3.5 (+/- 1 SD, range 8.0-14.9). These values were obtained using cells subcultured in medium supplemented with 10% fetal bovine serum (FBS) 21 h prior to assay. When cells were deprived of cholesterol by subculturing for 21 h in delipidated FBS, the mean value for patient cells was increased to 230.8 +/- 78.5 pmol/min-mg protein (range 130.9-333.8) as compared to 109.5 +/- 47.1 (range 78.0-163.6) for controls. The activity of HMG-CoA synthase in extracts of fibroblasts derived from the patients was not elevated. The mevalonic acid concentration in the surrounding culture medium was assessed by stable isotope dilution assay. For five patients, the mean concentration in medium containing FBS was 0.92 +/- 0.37 microM (+/- 1 SD, range 0.46-1.48) in contrast to 1.24 +/- 0.83 microM (range 0.46-2.54) for cells subcultured in delipidated FBS. The mean value for three control fibroblast lines was 0.22 +/- 0.12 microM (+/- 1 SD, range 0.11-0.35) for cells subcultured in FBS as compared to 0.01 +/- 0.01 microM (range 0.0-0.01 microM) for cells sucultured in delipidated FBS.(ABSTRACT TRUNCATED AT 250 WORDS)     

The erythrocyte insulin receptor response to insulin induced hypoglycaemia

The response of the erythrocyte insulin receptor to a prolonged intravenous infusion of insulin has been measured in normal individuals during hypoglycaemia and when hypoglycaemia was prevented by the concurrent infusion of glucose. When euglycaemia was maintained, mean (+/- S.D.) specific insulin binding following the 5 hour insulin infusion was unchanged (6.9 +/- 2.1 to 6.65 +/- 2.2% bound per 2.25 X 10(9) erythrocytes). In the presence of mild hypoglycaemia, mean (+/- SD) specific insulin binding rose from 6.6 +/- 2.3 to 7.6 +/- 2.5% bound per 2.25 X 10(9) erythrocytes (P less than 0.01), after 5 hours. This increase was due to increased receptor affinity. It was not correlated with the increase in the concentration of any individual counter-regulatory hormone. Initial insulin receptor binding correlated strongly with the subsequent decline in plasma glucose concentration (r = 0.9527; P less than 0.01). Thus, acute hyperinsulinaemia, when associated with hypoglycaemia, does not result in downregulation of insulin receptors on erythrocytes but rather results in increased receptor binding. Consequently, the insulin receptor may not play an active role in protecting the individual against acute hypoglycaemia.     

Effect of substance P on neurally mediated contraction of rabbit airway smooth muscle

The neuromodulatory action of substance P (SP) was investigated in isolated rabbit tracheal smooth muscle (TSM) segments contracted with electrical field stimulation (ES). The tissues were placed in organ baths containing modified Krebs-Ringer solution and stimulated at a constant voltage (8 V; 24.5 mA) and pulse duration (2 ms) with ES frequencies ranging from 1 to 100 Hz. In the presence of SP, there occurred a dose-dependent augmentation of the TSM contractile response to any given ES, with the maximal effect of SP obtained at a dose of 10(-7) M. Accordingly, with the administration of 10(-7) M SP, the ES frequency-response relationship was altered so that 1) the mean (+/- SE) maximal tension (Tmax) induced by ES significantly increased (P less than 0.02) from a base-line value of 273 +/- 53 to 402 +/- 45 g/g TSM; and 2) the mean (+/- SE) log ES frequency producing 50% of Tmax (ES50) significantly decreased from a base-line value of 1.278 +/- 0.069 to 1.102 +/- 0.070 Hz (P less than 0.01). In contrast to these effects on ES-induced contraction, SP administration did not affect the TSM contractile response to administered methacholine chloride (10(-8) to 10(-3) M). On the other hand, the effects of SP on ES-induced contraction were independently blocked by the cholinergic antagonist, atropine (10(-6) M); the neurotoxin, tetrodotoxin (10(-6) g/ml); and the SP antagonist, D-Arg1,D-Pro2,D-Trp7,9,Leu11-SP (10(-5) M).(ABSTRACT TRUNCATED AT 250 WORDS)     

Seroepidemiological study of Herpes simplex virus type 2 in adult women of Costa Rica]

The frequency of genital Herpes simplex type 2 infections in a group of twenty adult Costa Rican women was studied by isolation of the virus and the measurement of neutralizing antibody activity in sera. The virus could not be isolated in any of the vaginal secretions. Neutralizing antibody activity to herpes virus types 1 and 2 was found in sera from sixteen subjects. An antibody II/I index equal to or larger than 87, indicative of infection with Herpes simplex type 2 was found in fifty per cent of the population studied, a second segment was composed by the subjects with indices below 87. Evaluation of antibody activity to Herpes simplex type 2 revealed that: a) only a small percentage of the women lacked detectable antibody activity to the virus; b) there is a significant difference (p < 0.005) between the mean number of years of sexual experience among the two population segments; and c) there is a positive correlation (p < 0.05) between II/I index values and age among the women of the population segment with a II/I index equal to or larger than 87.     

Cytogenetic findings in acute myelogenous leukemias (FAB M 1 to M 6)

The results published in the period from 1973 to 1983 entitled "Cytogenetic findings in acute myeloic leukemias" (M 1 to M 6 of FAB classification) were compiled. In 50-60 per cent of those patients affected with acute myeloic leukemia a deviating karyotype could be detected. With a markedly higher frequency chromosomes 8 and 21 will take part in aberrations, with translocations (8; 21) having the main share with about 30-40 per cent. More than half the male bearers of translocation exhibits a loss of the Y-chromosome, a third of female patients a loss of the X-chromosome. Trisomy 8 and 9 as well as monosomy 7 appear in about 20 per cent. These aberrations can also be found in all other leukemic and preleukemic processes. Patients with karyotypic abnormalities in all their cells will have the slightest average survival time and the worst appeal to therapy. The sole appearance of monosomy 7 or Ph1-chromosome respectively seems to be an unfavourable sign from a prognostic point of view. Children with acute myeloic leukemia will possess an aberrant karyotype more frequently than adults, but they have a longer average life, boys are more frequently affected by this. Acute promyelocytic leukemia can be characterized cytogenetically in 94 per cent of the cases by translocation (15; 17). However, distinct geographical differences can be observed here, the causes of which have not been elucidated. About 40 per cent of the patients with acute myelo-monocytic leukemia developed aberrations. Further investigations will have to show whether the chromosome 11 really took part in it somewhat more frequently than merely at random. Chromosome anomalies have not a visible influence on the course of the disease. In 30-40 per cent of patients with a rarely occurring acute monocytic leukemia, an abnormal karyotype could be found. There was an incidence of 47 per cent for a specific translocation (9; 11) or a similar variant respectively. Erythroleukemia is characterized by a high instability of chromosomes and karyotypical variability, particularly in erythrocyte precursors and by an average survival time of one months. Megakaryoblastic and eosinophilic leukemia are very rare kinds of acute leukemias. The small number of publications allows no general statement to be made concerning karyotypical changes.     

Characterization and Regional Distribution of α2-Adrenoceptors in Postmortem Human Brain Using the Full Agonist [3H]UK 14304

The full agonist [3H]UK 14304 [5-bromo-6-(2-imidazolin-2-yl-amino)-quinoxaline] was used to characterize alpha 2-adrenoceptors in postmortem human brain. The binding at 25 degrees C was rapid (t1/2, 4.6 min) and reversible (t1/2, 14.1 min), and the KD determined from the kinetic studies was 0.48 nM. In frontal cortex, the rank order of potency of adrenergic drugs competing with [3H]UK 14304 or [3H]clonidine showed the specificity for an alpha 2A-adrenoceptor: UK 14304 approximately equal to yohimbine approximately equal to oxymetazoline approximately equal to clonidine greater than phentolamine approximately equal to (-)-adrenaline greater than idazoxan approximately equal to (-)-noradrenaline greater than phenylephrine greater than (+/-)-adrenaline much greater than corynanthine greater than prazosin much greater than (+/-)-propranolol. GTP induced a threefold decrease in the affinity of [3H]UK 14304, with no alteration in the maximum number of binding sites, suggesting that the radioligand labelled the high-affinity state of the alpha 2-adrenoceptor. In the frontal cortex, analyses of saturation curves indicated the existence of a single population of noninteracting sites for [3H]UK 14304 (KD = 0.35 +/- 0.13 nM; Bmax = 74 +/- 9 fmol/mg of protein). In other brain regions (hypothalamus, hippocampus, cerebellum, brainstem, caudate nucleus, and amygdala) the Bmax ranged from 68 +/- 7 to 28 +/- 4 fmol/mg of protein. No significant changes in the KD values were found in the different regions examined. The binding of [3H]UK 14304 was not affected by age, sex or postmortem delay.(ABSTRACT TRUNCATED AT 250 WORDS)     

The management and outcome of higher order multifetal pregnancies: obstetric, neonatal and follow-up data.

The objective of this study was to describe current obstetric, neonatal, and long-term neurodevelopmental outcomes of higher order multifetal gestations (> or = 3 fetuses) in the 1990s. We also intended to identify a target gestational age at which neonatal and neurodevelopmental morbidities are low. Records from all multifetal pregnancies (> or = 3 viable fetuses > or = 20 weeks gestation) delivered at the two perinatal centers in Toronto, Ontario, Canada during the study period (January 1, 1990-December 31, 1996) were reviewed. Data were collected on obstetric, neonatal, and long-term neurodevelopmental outcomes. Follow up data were gathered regarding the presence of a severe deficit in four categories (vision, hearing, cognition, and motor skills). Statistical analysis was performed to determine a gestational age at which a significant decrease in deficit occurred. During the study period 165 multifetal pregnancies were delivered. This resulted in 511 fetuses, of which 496 were live births. Of these 496 infants, 453 survived to discharge. Follow up data were obtained on 332 (73.3 per cent) infants. Infant survival increased with gestational age, and was approximately 90 per cent or greater at 26 weeks or more. Of all infants followed, the proportion of those without deficit increased with increasing gestational age, such that the percent without deficit was 96.9 at 31 weeks or greater. Of all infants followed, 301 (90.7 per cent) had no deficit. Statistical analysis revealed a significant difference in long-term neurodevelopmental outcome between infants born before and after 28 weeks gestation. The incidence of a major deficit was 44.1 per cent for those born earlier than and 5.4 per cent for those born later than this gestational age (p = 0.001). In our cohort, survival figures were high. Even in lower gestational groupings, survival was high, but not without serious concerns about severe morbidity. This information is useful when counseling parents of higher order multifetal pregnancies.