Overproduction of discoidin I by a temperature-sensitive motility mutant of Dictyostelium discoideum

Dictyostelium discoideum MC2 is a temperature-sensitive motility mutant of AX3. Mutant cells are incapable of growth, phagocytosis, and migration under restrictive conditions (Kayman et al., J. Cell Biol. 92:705-711, 1982). We show here that at the restrictive temperature MC2 cells grown axenically or on bacteria synthesized excessive quantities of the lectin discoidin I. By two-dimensional gel electrophoresis and peptide mapping, the proteins overproduced by MC2 cells were indistinguishable from discoidin I synthesized at lower levels in AX3 cells. At least two of the three species of discoidin I were overproduced. This protein family constituted 9% of the total protein in cells that were incubated overnight at 27 degrees C in axenic medium. Although MC2 cells are defective in nutrient uptake under restrictive conditions, the overproduction of discoidin I did not appear to be part of a pleiotropic response to starvation. We propose that transcription of the coordinately regulated discoidin I genes is altered in mutant cells. This alteration may be related to the motility defects manifested by MC2.

2-Mercapto-ethanol enhancement of agglutination reaction--a possible in vitro serological correlate for assessment of functional immunity in simian malaria

Conventional indirect haemagglutination test was performed in rhesus monkey sera (collected from Plasmodium knowlesi infected animals) with and without prior treatment of sera with 2-mercapto-ethanol (2-ME). Surprisingly, many sera samples showed significant enhancement of final titre with 2-ME. The 2-ME enhancement effect was more pronounced in the sera of hyperimmune monkeys on further injection of antigen or parasites. It was also noticeable in the sera during primary drug-suppressed P. knowlesi infection and appeared to have a bearing on the immune status of the animals to rechallenge. The use of a soluble antigen prepared from P. knowlesi infected erythrocytes was found to be essential in IHA test to demonstrate the 2-ME enhancement effect. Antigen prepared from freed parasites (commonly used) failed to show a similar effect in IHA. The possible role of certain T-lymphocyte products - antigen binding, non-agglutinating, 2-ME sensitive molecules - in malarial immunology has been proposed.

Enhanced seminal plasma ribonuclease activities in azoospermia, severe oligiozoospermia, and asthenozoospermia

Acid and alkaline ribonuclease (RNAase) activities were measured in human seminal plasma. The samples were obtained from patients attending an Infertility Clinic and were separated into groups according to the concentration and motility of spermatozoa. Levels of acid and alkaline RNAase activities in seminal plasma were, respectively, 22 and 13 times the values found in blood plasma. The severe oligozoospermic and azoospermic groups showed significantly higher alkaline RNAase activities in the seminal plasma than the normozoospermic group. The group with sperm motility < 50% showed significantly higher acid and alkaline RNAase activities than the group with motility greater than or equal to 50%. Enhanced RNAase activities may be involved in the process of bringing about a reduced formation and maturation and a reduced motility of spermatozoa.

Maternal plasma, human placental lactogen, alpha-fetoprotein, prolactin and growth hormone in early pregnancy

Human placental lactogen (HPL), alpha-fetoprotein, prolactin and growth hormones were assayed simultaneously twice weekly in 21 women from 4--16 weeks' gestation. Mean levels were established from 15 of the women for comparison with one woman with a twin pregnancy, two who aborted and three who received progestogen supplements. There was wide interpatient variation in all hormone levels excepting HPL. The mean levels of all except growth hormone showed an upward trend. Mean growth hormone levels were higher initially but remained within a 2--4 ng/ml range throughout. In the twin pregnancy, only HPL and alpha-fetoprotein levels were significantly raised. HPL was detected in one of the two women who aborted, whereas growth hormone was initially extremely high, falling precipitously prior to abortion in both women. Treatment with progestogen supplements did not appear to influence any of the hormones measured. This study suggests that serial estimations of HPL appear to be the most cost-effective guide to early fetal well-being of the four hormones measured.

Fructose and hormone levels in semen: their correlations with sperm counts and motility

Levels of fructose, growth hormone (GH), prolactin (HPr), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and 5alpha-dihydrotestosterone (DHT) were determined in semen. The samples were obtained from patients attending an infertility clinic and separated into four groups according to the number of spermatozoa. Levels of HPr, LH, and FSH showed significant positive correlations with sperm counts. Significant differences in fructose and hormone levels were found between various groups. Expressed as concentrations of hormones or fructose per milliliter of semen, none of the hormones showed a significant negative correlation with sperm motility whereas fructose showed a significant negative correlation. Expressed as amounts per ejaculate of semen, only prolactin showed a significant positive correlation with sperm motility. The significance of these findings is discussed.

Graft interposition splenocaval shunt for total or selective decompression of portal hypertension

A new operation for selective or total decompression of the portal venous system in cases of intrahepatic portal hypertension is described. It involves interposition of a large-caliber Dacron graft between the splenic vein and the inferior vena cava. The graft-interposition splenocaval shunt is performed readily and quickly, satisfying the variable hemodynamic needs of patients with portal hypertension. It can be either selective (S-SCS) or total (T-SCS) from the beginning, or a T-SCS may be converted subsequently to a S-SCS should surgically induced hepatic decompensation supervene. It is less demanding technically than distal splenorenal shunt (D-SRS). The S-SCS conserves portal venous perfusion of the liver, preserves hepatocellular function and architecture at the preoperative levels, avoids precipitation of postshunt portal-systemic encephalopathy, and decompresses gastric-esophageal varices with prevention of further variceal bleeding even better than D-SRS. One hundred percent graft patency has been obtained, and the surgical results have been superior to those following portacaval shunt in patients with large liver blood flow and relative benignity of the liver disease, be it cirrhosis or noncirrhotic portal fibrosis. In patients with advanced cirrhosis, variceal bleeding, and small liver blood flows, T-SCS would be indicated. Patients of this category obtained inferior surgical results and had operative deaths (16.7%) following S-SCS. The concept of the operation has merits and deserves further evaluation.

Calculation of Surface Deformation in Point Contact EHD

The paper describes three different numerical techniques for the accurate evaluation of the elastic deformation in elastohydrodynamic point contacts. The first method relies on a first order representation of the pressure distribution over triangular elements whereas the second and third methods use a second order method with rectangular elements. Comparison of results obtained using the numerical techniques described with known, exact values indicates that accuracies better than one percent can be expected when using the methods in the ehd problem.

Inhibition of puerperal lactation. A double blind study of bromocriptine and placebo

Bromocriptine and placebo were randomly allocated for three weeks to 52 postpartum patients requiring lactation suppression. Bromocriptine significantly lowered plasma prolactin levels and suppressed breast milk, breast pain and engorgement quicker than placebo. No side-effects were noted and rebound lactation did not occur. Menstruation appeared to re-start sooner when Bromocriptine was given.

Prolactin in amniotic fluid: its correlation with maternal plasma prolactin

Prolactin concentrations in amniotic fluid from 319 women with normal pregnancies and 29 women with complicated pregnancies were determined by radioimmunoassay. Prolactin levels varied from 36 ng/ml to 1800 ng/ml mean +/- S.D. = 408 +/- 297) in the normal pregnancy group but showed no definite pattern of rise or fall during pregnancy. No difference in levels was found in complicated pregnancies. Prolactin concentrations in the plasma from 203 of these women were also assayed. The levels in the amniotic fluid were about 9 fold higher than those in the plasma. There was no significant correlation between amniotic fluid and plasma levels of prolactin.

Elastohydrodynamic Lubrication of Spherical Surfaces of Low Elastic Modulus

The paper presents a numerical solution for the elastohydrodynamic lubrication of low modulus point contacts which is broadly equivalent to the theory of Grubin for materials of high elastic modulus. The theoretical results obtained for the variation of minimum film thickness using this approach are therefore expected to apply to conditions of high load and low speed. For less severe conditions in which elastic deformation is less significant an alternative approach has been developed. Results of this analysis show the transition from undeformed to heavily loaded conditions. The effect of lubricant starvation has been examined for heavily loaded conditions and the theoretical results are compared with those obtained previously for high elastic modulus point contact.

Plasma prolactin levels during pregnancy

Plasma prolactin levels in women who were between 8 and 40 weeks pregnant were determined by a homologous double antibody radioimmunoassay method. There were 980 samples from 839 uncomplicated and 213 samples from 116 complicated pregnancies. Prolactin levels in normal pregnancies varied from 6 ng/ml during early pregnancy to 210 ng/ml near term. A few values beyond the normal range were found in various groups of complicated pregnancies. About 14 per cent of samples from patients with threatened abortion and 7 per cent from patients with hypertension were above the upper normal range. The proportion of values below the 10th centile in patients with a low urinary oestrogen excretion was significantly higher than that in the normal population. Plasma prolactin levels did not seem to be a valuable guide to maternal or fetal well-being.

Hormonal assessment before and after vasectomy

Animal experiments have suggested that vasectomy may disturb the endocrine function of the testis. To explore this possibility in man blood was obtained from 277 men who had undergone vasectomy up to six years earlier or who were about to undergo the operation. Mean plasma testosterone concentrations seemed to be slightly higher in those who had undergone vasectomy than in the preoperative group, although this difference was not statistically significant. There was no significant difference between these two groups in the concentrations of luteinising hormone, follicle-stimulating hormone, prolactin, or oestradiol.

Maternal plasma alpha-fetoprotein in normal and complicated pregnancies

Plasma alpha-fetoprotein (AFP) has been estimated by radioimmunoassay in healthy non-pregnant adults, some of whom were taking oral contraceptives, and in women with normal and complicated pregnancies. A curve with the 90 per cent range in normal pregnancy was established. The prop&rtion of values below the 5th centile in complicated pregnancies was significantly greater than in uncomplicated pregnancies. However, three-quarters of the estimations in the complicated groups lay within the 90 per cent range. Nor correlation was found between maternal plasma AFP values and the incidence of fetal distress, small-for-dates babies or perinatal mortality. It is concluded that the measurement of maternal plasma AFP is not reliable test for predicting fetal well-being.

Effects of norethisterone on pituitary and ovarian function

The effect of norethisterone (17α-ethynyl-17β-hydroxy-19-norandrost-4-en-3-one) on certain aspects of pituitary and ovarian function has been investigated in seven healthy women. Twenty-four urine samples were collected daily throughout control cycles and subsequently during the second cycle of treatment with 0.35 mg/day of norethisterone. LH, FSH and total oestrogens were measured in all urine specimens and the level of pregnanediol-3α-glucuronoside on selected days during the luteal phase. In addition, progesterone, 17-hydroxyprogesterone and oestradiol were determined in peripheral venous plasma nine days after the peak of urinary LH. At the same time, progesterone secretion and metabolism were assessed from the analyses of urinary metabolites following the intravenous administration of labelled progesterone.

The results show that, in general, norethisterone at this dose does not affect either the level or pattern of FSH, but in five subjects, there was a variable reduction in the midcycle peak of LH (to 33–85 % of the control value). In six subjects, there was a marked reduction in the levels of urinary pregnanediol (to 8–80% of the control value), plasma progesterone (16–55 %), and the urinary production rate of progesterone (3–51 %). In contrast, the level of urinary oestrogen per cycle was increased to 140–160 % in all subjects and the mean values showed an abnormal cyclical pattern. Changes in the distribution of labelled metabolites during treatment indicated the existence of at least two pools of progesterone metabolism.

Human chorionic somato-mammotrophin in serum and urine in various stages of pregnancy: its correlation with enzymes and oestrogens

Human chorionic somato-mammotrophin (HCS) and the activities of heat-stable alkaline phosphatase (HSAP) and cysteine aminopeptidase (CAP) in the serum of normal pregnant women were studied. The hormone and enzymes were detectable at the early stage of pregnancy and all showed an increase with the progress of gestation. A highly significant correlation was found between HCS and activities of HSAP and CAP during all stages of gestation.

Human chorionic somato-mammotrophin and oestrogens were measured in the urine of pregnant women. The correlation coefficient between these factors was smaller than that found between serum enzymes and HCS but was still significant.