Sex determination and polyploid gigantism in the dwarf surfclam (Mulinia lateralis Say)

Mulinia lateralis, the dwarf surfclam, is a suitable model for bivalve genetics because it is hardy and has a short generation time. In this study, gynogenetic and triploid M. lateralis were successfully induced. For gynogenesis, eggs were fertilized with sperm irradiated with ultraviolet light and subsequently treated with cytochalasin B to block the release of the second polar body (PB2). Triploidy was induced by blocking PB2 in normally fertilized eggs. The survival of gynogenetic diploids was very low, only 0.7% to 8 days post-fertilization (PF), compared with 15.2% in the triploid groups and 27.5% in the normal diploid control. Larvae in all groups metamorphosed at 8-10 days PF, and there was no significant post-larval mortality. At sexual maturation (2-3 months PF), all gynogenetic diploids were female, and there was no significant difference (P > 0.05) in sex ratio between diploids and triploids. These results suggested that the dwarf surfclam may have an XX-female, XY-male sex determination with Y-domination. Compared with diploids, triploids had a relative fecundity of 59% for females and 80% for males. Eggs produced by triploid females were 53% larger (P < 0.001) in volume than those from diploid females. In both length and weight measurements at three months PF, the gynogenetic diploids were not significantly (P > 0.33) different from normal diploid females, suggesting that inbreeding depression was minimal in meiosis II gynogens. Triploid clams were significantly larger (P < 0.001) than normal diploids. We hypothesize that the increased body-size in triploids was caused by a polyploid gigantism due to the increased cell volume and a lack of cell-number compensation.     

Vitamin D metabolism in tilapia (Oreochromis mossambicus)

We have studied the protamine scombrine alpha from the mackerel Scomber scombrus. Scombrine alpha is found phosphorylated in spermatid nuclei, but not in nuclei of ripe sperm. It is a typical fish protamine, made up of two distinct molecular species, each of 34 amino acid residues. The primary structure of the main component of scombrine alpha is 100% identical to scombrine gamma, the nonmicroheterogeneous protamine from Scomber australasicus (11). The second component of scombrine alpha is a very minor molecular species that has an isoleucine instead of a valine in position 11. Nuclear sperm-specific basic proteins display an enormous interspecific variability and it is very surprising that two different species show identical protamines. In this work we suggest that evolutionary changes in primary structure of protamines are restricted by several constitutive factors, especially when protamines either lack or have a low degree of microheterogeneity.     

Efferent and afferent connections of the nucleus lateralis posterior thalami ("pulvinar") in the albino rats (author's transl)

The efferent and afferent connections of the lateral posterior nucleus (LP) of the albino rat were investigated light microscopically with the silver-degeneration-methods and the HRP-methods as well. The results are: 1. The main projection region of the LP is the area of 18a of the peristriate visual cortex. Most degenerating axons terminate in layer IV. A few fibers pass layers III and II and terminate in layer I. It is not sure if there are also terminating fibers in layer IV. We could not find a topistic relation between LP and area 18 a. 2. We observed a small number of degenerating fibers in area 17, too. 3. A part of the degenerating fibers runs to the temporal cortex end enters area 20. 4. There is no evidence for a projection of the LP to both the subcortical regions and to the superior colliculus. 5. The majority of the LP's afferent fibers originates - on the subcortical level - from the superior colliculus. Especially the lamina III (Str. opticum) of the ipsilateral and of the contralateral side is here the source of fibers terminating in the LP. 6. Other subcortical sources of fibers terminating in the LP are: the pretectal region, the ventral part of the LGN, the Zona incerta, the thalamic reticular formation, and the dorsal raphe nucleus. 7. There exists a fiber projection of the area 17 to the LP. The axons originate mainly from pyramidal cells in layer V. It is discussed whether the area-17-fibers terminating in the LP are collaterals of the fibers terminating in the superior colliculus. The projection of the area 18a to the LP is of greater importance. The axons of this area originate mainly from cells of the layer VI. It becomes obvious that the thalamic relay-station of the second visual pathway seems to project nearly exclusively to the neocortex. In contrast to the dorsal LGN, however, the LP is not only a simple relay-station for visual information as also non-visual information arrives here. The morphological basis for these inputs has not yet been clarified completely. We have to take into consideration as well as the connections with the superior colliculus and the pretectal region and the cortical connections. It is remarkable that there exists also a projection of LP-fibers to a region outside the classical visual cortex. In mammals of higher evolution that kind of projection extends increasingly. It is discussed if - under comparative-anatomical aspect - the morphological changes in the pulvinar region are an expression of the neocorticalization, whereas the morphological changes in the dorsal LGN reflect mainly the functional specialization of the visual system.     

Muscle metabolism and quality (MQI) in prediabetic sedentary man

In the present study, we compared the basal local cerebral metabolic rates for glucose (LCMRglcs) both in Wistar rats with genetic absence epilepsy (GAERS: genetic absence epilepsy rats from Strasbourg) and in control non epileptic (NE) rats selected in our breeding colony. LCMRglc was measured both in immature rats at postnatal day 21 (P21) at which age no spontaneous spike-and-wave discharges can be recorded in GAERS and at the adult age (6 months) when GAERS fully express thalamo-cortical spike-and-wave discharges recorded on the EEG. LCMRglcs were measured in 24 structures by the quantitative [14C]2-deoxyglucose autoradiographic technique. In adults GAERS, LCMRglc underwent a widespread increase recorded in all brain structures except in mediodorsal and ventromedian thalamus, and in the nucleus accumbens. These metabolic increases ranged from 17 to 50% over control levels in adult NE rats. In P21 GAERS, LCMRglc was similar to that of P21 NE rats in 16 areas. It increased over control levels of NE rats in two groups of structures. Metabolic increases were recorded in four limbic structures (entorhinal and piriform cortices, hippocampus and basolateral amygdala) where no spike-and-wave discharges were recorded in adult GAERS. Increases in LCMRglcs were also located in the substantia nigra pars reticulata, superior colliculus and globus pallidus which are structures involved in the control of seizure activity. In conclusion, our data suggest that the consequences of the genetic mutation(s) underlying the cellular and molecular events responsible for the expression of spike-and-wave discharges in adult GAERS is (are) able to increase metabolic activity in both limbic structures and the nigral inhibitory system before the occurrence of spike-and-wave discharges.     

Diabetes mellitus and lipid metabolism (author''s transl)

Fifteen infants with pneumonia caused by respiratory syncytial virus (RSV) and 19 infants with bronchiolitis caused by RSV were studied for the influence of homologous, circulating neutralizing antibody on the severity of their illness. All infants were under nine months of age. Although maternal neutralizing antibody did not prevent infection with RSV and illness, the severity of pneumonia caused by RSV was inversely related to the level of neutralizing antibody. The severity of bronchiolitis caused by RSV was unrelated to maternal antibody levels. Chest roentgenograms showed pneumonia to be slightly more severe than bronchiolitis. Neither the severity of illness nor the presence of maternal neutralizing antibody was related to the development of complement-fixing antibody.     

Phospholipid metabolism in European house dust mite (Acari: Pyroglyphidae)

Phospholipid metabolism was studied in European house dust mite, Dermatophagoides pteronyssinus (Trouessart). Analysis of phospholipid metabolites in mite extracts suggested the presence of PLaseA1, PLaseA2, and PLaseC, which have important physiological roles in phospholipid metabolism. The optimum pH of PLaseA1 and PLaseA2 was 8 and 9, and the optimum temperature of PLaseA1 was 45 degrees C; the activity of PLaseA2 was not affected by temperature. The activity of PLaseA1 at pH 8 and 37 degrees C was 5 times higher than that of PLaseA2 in D. pteronyssinus. The optimum temperatures of diacylglycerol production were 25 and 45 degrees C.     

Changes in aminophenazone metabolism with acute hepatitis in children (author's transl)

Serum half-life of aminophenazone was measured in 23 children with acute viral hepatitis and children with normal liver biopsy of matched ages. In acute hepatitis the value was 6.71 +/- 3.34, significantly longer than in the normal controls (2.79 +/- 0.53). Two hours after oral intake of the drug the serum concentration was higher in healthy children than in those with hepatitis, but the difference was not significant. Especially in children with intercurrent acute hepatic disease account must be taken of impaired metabolism during long-term drug treatment.     

Effect of alcohol (ethanol) administration on sex-hormone metabolism in normal men

To determine whether ethanol per se affects testosterone metabolism, alcohol was administered to normal male volunteers for periods up to four weeks, resulting in an initial dampening of the episodic bursts of testosterone secretion followed by decreases in both the mean plasma concentration and the production rate of testosterone. The volunteers received adequate nutrition and none lost weight during the study, which tended to exclude a nutritional disturbance as the cause of the decreased testosterone levels. The changes in plasma luteinizing hormone suggested both a central (hypothalamus-pituitary) and gonadal effect of alcohol. In addition, alcohol consumption increased the metabolic clearance rate of testosterone in most subjects studied, probably owing to the combined effects of a decreased plasma binding capacity for the androgen and increased hepatic testosterone A-ring reductase activity. These results indicate that alcohol markedly affects testosterone metabolism independently of cirrhosis or nutritional factors.     

Percutaneous penetration and metabolism of topical (14C)flutamide in men

This study was designed to determine the fate of the nonsteroid antiandrogen flutamide in men following a single 6-hr topical application of 5 mg 14C-labeled drug dissolved in 50% ethanol/50% propylene glycol. Analysis of 0-120 hr urine shows at least 16% of the applied flutamide is absorbed. Fifty-six percent of the dose is recovered from the site of application with cotton swabs moistened with 50% ethanol/50% propylene glycol. Flutamide plasma levels peak in 4 to 6 hr at about 1.3 ng/ml and then decline rapidly to about 0.08 ng/ml 24 hr after application. Only 13% of plasma 14C is associated with flutamide 6 hr after drug application. There are at least 10 plasma metabolites, of which 6 have been tentatively identified. These are alpha, alpha, alpha-trifluoro-4'-amino-m-acetotoluidide (A); alpha, alpha, alpha-trifluoro-4'-amino-2-methyl-m-lactotoluidide (B); alpha, alpha, alpha-trifluoro-4'-nitro-m-acetotoluidide (C); alpha, alpha, alpha-trifluoro-2-methyl-4'-nitro-m-lactotoluidide (D); alpha, alpha, alpha-trifluoro-4'-amino-2-methyl-m-propionotoluidide (E); and alpha, alpha, alpha-trifluoro-6-nitro-m-toluidine (F). (D) is the major plasma metabolite, and its concentration exceeds flutamide's between 8 and 24 hr after drug. All the plasma metabolites are found in 0-24 hr urine in minor amounts. An additional metabolite, alpha, alpha, alpha-trifluoro-amino-5-nitro-p-cresol (G), accounts for 27% of urine 14C.     

Influence of various doses of aspirin (in vivo) on platelet arachidonic acid metabolism (ex vivo) and function

It has been reported that aortic homografts that have been cryopreserved before transplantation remain viable longer as an allograft than tissue stored at 4 degrees C in an antibiotic solution. In the present study, we tested the hypothesis that storage of cardiac valve tissue by cryopreservation or by antibiotic preservation may alter the metabolic status of the tissue. Initially, we collected aortic valves composed of cardiac tissue, aortic root, and valvular tissue from cadaver donors. These specimens were divided into three equal portions, and one portion was analyzed before storage while the other two parts were stored for 3 weeks at either 4 degrees C in an antibiotic solution or at -196 degrees C in liquid nitrogen. All specimens were examined with regard to the following parameters: tissue structure, tissue viability, cell proliferative capacity, metabolic function, and identification of cell-specific antigens. We found no significant alterations in the structure of any of the three tissue components after antibiotic preservation or cryopreservation; however, cell viability and cell number were decreased in all three groups. All tissue samples grew in culture before storage. When we compared activities of the following organellar marker enzymes--lysosomal acid lipase, plasma membrane 5' nucleotidase, mitochondrial cytochrome oxidase, and microsomal neutral alpha-glucosidase--we observed no major differences between tissues stored by either technique. In addition, we observed no loss of enzymic activity as a result of storage. Finally, when cell lines isolated from each tissue specimen were incubated with monoclonal antibodies against cell-specific antigens in an immunoperoxidase assay, all the cell cultures proved to be endothelial cells. These results suggest that although cardiac valve tissue stored by cryopreservation or by antibiotic preservation retained its normal structure and metabolic capabilities, both storage techniques produced significant decreases in cell numbers and viability. However, only endothelial cells from tissue stored by cryopreservation retained the capacity to proliferate in vitro. These findings have important implications for the function of aortic homografts transplanted after storage.