Influence of microbial concentration on the rheology of non-Newtonian fermentation broths

The objective of this study was to quantify the effect of fungal biomass concentration on the rheology of non-Newtonian fermentation systems. Batch fermentations of Penicillium chrysogenum were carried out with glucose as the sole carbon source. The flow behavior of the system was characterized at various fermentation times and was adequately described by the power-law model. The apparent viscosity of the fermentation broth was significantly affected by biomass concentrations in the fermenter. Fermentation broths containing 17.71 g/l biomass as dry weight were characterized by an apparent viscosity of 0.25 Pa s at a shear rate of 50 s-1. Microbial concentration also affected the power-law flow-behavior index and the consistency index. The value of the consistency index ranged from 0.002 Pa sn at a biomass concentration of 0.1 g/l to 6.14 Pa sn at a biomass concentration of 17.71 g/l. The flow-behavior index decreased from an initial value of 1 to a final value of 0.17. Simple empirical correlations have been proposed to quantify the dependence of the power-law parameters on fungal biomass concentration. Experimental data obtained in this study were accurately described by these correlations. The general applicability of these relationships was tested, using previously published rheological data on Aspergillus awamori and Aspergillus niger fermentation broths, and good agreement was seen between experimental data and the predictions from the empirical correlations.

Arylsulfatase A and beta-galactosidase activities in leukocytes and lymphocytes from normal and psychiatric subjects. Effects of blood-processing delay and interleukin-2 stimulation

Arylsulfatase A (ASA) and cerebroside-beta-galactosidase activities in leukocytes serve as a diagnostic tool for determining the presence of metachromatic leukodystrophy and globoid cell leukodystrophy, respectively. It has not been demonstrated whether a delay in blood processing and the presence of mixed cell types in different proportions in leukocytes affect the activities of the two enzymes in these cells. We have in the present study determined the specific activity in leukocytes and lymphocytes (T-cells) prepared from blood samples processed immediately after, 4, and 24 h after collection. In order to determine whether the enzyme activities in lymphocytes reflect expression of genetic trait, and not environmental or "state" influence, the activities of the two enzymes in interleukin 2-stimulated T-cells and resting T-cells were compared. A delay of up to 24 h in blood processing did not significantly change the specific activities of the two enzymes in both leukocytes and lymphocytes. The specific activity of ASA and beta-galactosidase in lymphocytes was 1.4-1.8 times that in leukocytes. The activities of the two enzymes in interleukin 2-stimulated T-cells did not differ from those in resting T-cells. These results indicate that blood-processing delay had no significant effects on ASA and beta-galactosidase activity. The data further indicate that the ASA and beta-galactosidase activity in interleukin 2-stimulated T-cells was not significantly different from resting lymphocytes from either normal or psychiatric subjects exposed to various medications. The activity levels in lymphocytes from psychiatric subjects thus reflect expression of genetic trait, rather than environmental or state influence.

Cocaine exposure prebreeding to weaning: maternal and offspring effects

In a model emphasizing prebreeding cocaine administration, rats exposed to cocaine (50 mg/kg) daily were compared to saline-injected and noninjected controls with respect to weight changes, food and water intake, maternal behavior, offspring weight, and activity. During the first 21 days cocaine-treated dams lost weight, while the control dams gained. Throughout gestation and the first 14 days of lactation all groups gained weight, but the cocaine-exposed dams never completely recovered from the initial anorectic effect. Except during the first week of exposure, cocaine dams ate and drank more than the normal controls and drank more than the saline group. During gestation there was no difference in food intake, although the cocaine dams continued to drink more than controls. During lactation there were no differences in food and water consumption across groups. However, the cocaine dams exhibited more nursing behavior. From birth to day 21, the offspring of cocaine-treated dams were smaller than those of either control group. By 51 days of age, group differences had disappeared. Cocaine-exposed pups and saline offspring tested at days 28 and 85 were more active than those of noninjected controls. The results indicate that administration of cocaine for a period prior to breeding and during gestation and lactation, a protocol which closely resembles human drug abuse patterns, is more devastating than the administration during gestation.

Polyorchidism discovered as testicular torsion

We report on a case of polyorchidism that presented as testicular torsion. A brief history and review of the literature is also presented. Of the 47 cases reported, this patient is the youngest.

Effect of serum lipoproteins on growth and sterol synthesis in cultured rat brain glial cells

Cells dissociated from brains of 1-day-old rats were cultured in medium containing either lipoprotein-deficient serum (LPDS) or LPDS plus various lipoprotein fractions. Increases in number of cells and in DNA content served as a measure of cell growth. Cholesterol synthesis was measured from the incorporation of [14C]acetate into total nonsaponifiable lipids and digitonin-precipitable sterols, and from the activity of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase. The data indicated that cholesterol biosynthesis from acetate was reduced in cells cultured in medium containing either LPDS plus low-density lipoproteins (LDL), high-density lipoproteins (HDL), or total lipoproteins (LP) and that this reduction was accompanied by a reduction in the activity of the HMG CoA reductase and an increase in the esterified sterol content. The reduction in cholesterol synthesis from acetate was maximal in cells cultured in the presence of HDL, whereas the maximal reduction in the activity of HMG CoA reductase occurred in cells cultured in the presence of LP. The presence of LDL or LP in the culture medium enhanced the cell growth but the presence of HDL did not. Esterified sterol content was highest in cells cultured in the medium containing LPDS plus LP and was not detected in cells cultured in LPDS medium. It is inferred from these data that rat brain glial cells in culture are able to utilize cholesterol in lipoproteins, that the presence of LDL in the medium enhances cell growth, and that reduced cholesterol synthesis in the presence of lipoproteins may occur at the HMG CoA reductase step as well as at some other step(s).

Cholesterol ester hydrolase(s) in mammalian brain: is there a myelin-specific cholesterol ester hydrolase?

The present study compared the properties of cholesterol ester hydrolase(s) in myelin and microsomes from rat, mouse and human brain. The results indicated that the enzyme activity in both myelin and microsomes from rat, mouse and human brain was optimal at pH 6.5 and required Triton X-100 for optimal activity. The enzyme activity in myelin was 3- to 4-fold higher in the presence of Triton X-100 than taurocholate. Addition of phosphatidyl serine enhanced (2 to 4 fold) the hydrolase activity in both myelin and microsomes. The properties of the enzyme in solubilized preparation of myelin were also similar to the properties of the enzyme in partially delipidated and solubilized preparations of microsomes. The activity was again optimal at pH 6.5, required Triton X-100 for optimal activity and was stimulated by phosphatidyl serine. These results indicate that the properties of cholesterol ester hydrolase in myelin are similar to those of the microsomal enzyme and that this is true for the fractions from both human and rodent brain. The data thus lead us to believe that the hydrolase activity in mammalian brain myelin and microsomes may reflect the distribution of a single enzyme in the two fractions rather than two distinct enzymes, one being specific to each fraction.

Growth and lipid composition of rat brain glial cells cultured in lipoprotein deficient serum

The purpose of this study was to examine the effects of substituting lipoprotein deficient serum (LPDS) for complete fetal calf serum (FCS) in culture media on the growth and lipid composition of cells dissociated from 1 to 2-day-old rat brain. The results show that in FCS cultures DNA, protein and all lipids increase with an increase in the number of days in culture. Substitution of LPDS for FCS in the culture media caused a slower increase in each of these constituents. Esterified cholesterol remained unaltered with time in LPDS cultures but increased continuously in FCS cultures. Substitution of LPDS for FCS reduced the DNA:protein ratio, and unesterified cholesterol:phospholipid ratio but the protein:phospholipid ratio and the proportion of individual phospholipids were not affected. The data indicate that removal of low density lipoprotein (LDL) from serum used in culture media reduces cell proliferation and causes alterations in cellular lipid composition specifically ratio of cholesterol:phospholipids.

Metabolism of intracerebrally injected mevalonate in brain of suckling and young adult rats

We have investigated the in vivo metabolism via sterol and nonsterol pathways of intracerebrally injected mevalonate (MVA) in brains from suckling (10-day-old) and young adult (60-day-old) rats. Results of our study indicated that increasing the amounts of MVA injected increased MVA incorporation into all the lipid fractions examined. The incorporation of MVA into nonsaponiable lipids (NSF) and digitonin precipitable sterols (DPS) was similar in brains from adult and suckling rats. In brain tissue from both suckling and young adult rats the synthesis of dolichol from MVA varied with the amounts of MVA injected. Significant amounts of MVA were recovered in phosphorylated and free polyprenols (farnesol and geraniol) in brain tissue from rats of both ages. Also in both groups of animals, the amounts of MVA incorporated in phosphorylated and free farnesol were higher than the amounts recovered in either, phosphorylated or free geraniol. The amounts of MVA incorporated into the prenoic/fatty acid fraction by brain tissue from both suckling and young adult rats were less than 1% of the total MVA incorporated (nonsaponifiable and saponifiable lipids). Incorporation of MVA into the prenoic/fatty acid fraction by brain tissue was higher in suckling than in young adult rats. These data indicate that the brain tissue from suckling and young adult rats do not differ in their capacity to metabolize MVA into squalene and sterols and that in brain, metabolism of MVA by a shunt pathway is minimal. This suggests that in vivo regulation of cholesterol synthesis during brain development must occur at a step(s) in the sterol synthetic pathway prior to mevalonate, and that metabolism of mevalonate by shunt pathway did not play a role in the developmental regulation of brain sterol synthesis. The data also suggest that in both groups of animals the synthesis of squalene by synthetase may in part control brain sterol synthesis and the synthesis of dolichol is regulated by MVA concentration in the tissue.

Prevalence of partial cerebroside sulfate sulfatase (arylsulfatase A) defect in adult psychiatric patients

Metachromatic leukodystrophy (MLD) is a disease caused by a deficiency of the enzyme sulfatide sulfatase, also known as arylsulfatase A (ASA). We compared the activity of this enzyme in adult psychiatric patients and normal volunteers using nitrocatechol sulfate (ASA-NCS) and cerebroside sulfate (ASA-CS) as substrates. Our results showed that ASA-NCS activity in urine and leukocytes was significantly lower in psychiatric than in normal individuals, but that there were no differences between these two groups in the sulfatide excretion in urine or the ASA-CS activity in leukocytes. There was no correlation between enzyme activity in urine and in leukocytes, indicating that activity in urine does not truly reflect the levels of the enzyme in tissues. The correlation between ASA-NCS and ASA-CS activity in leukocytes was poor (0.51 for psychiatric patients and 0.59 for normals), suggesting that for a valid measure of the enzyme activity the assays should be carried out with CS as substrate. Results of our study also indicate that in 39 of the 145 psychiatric patients studied, the ASA-CS activity in leukocyte was less than 4 nmoles/mg protein/hr, which is below 50% of the normal means, whereas only one of the 30 normal subjects had a value this low. The presence of low levels of ASA-CS activity in a significantly large number of adult patients with varying psychiatric manifestations suggests that such patients may be asymptomatic carriers of the sulfatidase defect (heterozygotes for MLD), and that behavioral and functional disturbances in these patients may at least in part be related to sulfatidase deficiency. The significance of the ASA-NCS abnormality (reduction) in psychiatric patients is unclear.

Failure of 5-hydroxytryptophan to modulate brain stem auditory evoked responses in myelin deficient mutant qk mice

The effect of 5-hydroxytryptophan (5-HTP) on brain stem auditory evoked response (BAER) amplitude in Quaking (qk) and normal littermate mice was examined. Administration of 5-hydroxytryptophan (5-HTP) (75 mg/kg, i.p.) to normal mice increased the amplitude of BAER peaks I, II, and III but had no effect on peak IV. In qk mice, however, 5-HTP did not affect the amplitude of any BAER peaks. Our data indicate that although 5-HTP increased BAER amplitude in normal mice, it failed to modulate BAER in qk mice. These findings are consistent with the possibility that 5-HTP receptor sites associated with myelin basic protein may be reduced in the myelin-deficient mutant qk mice.

Effect of hyperphenylalaninemia induced during suckling on brain DNA metabolism in rat pups

We studied DNA metabolism (synthesis and degradation) in brain to investigate the effect of hyperphenylalaninemia induced in rats by treatment with PCPA or alpha MPA plus PHE during suckling (4th-20th days of postnatal age) on cell proliferation and naturally occurring cell death. The incorporation of 14C in DNA as percent of total radioactivity in the tissue, 30 min after administration of [14C]thymidine served as a measure of DNA synthesis in vivo, and the amount of radioactivity recovered in DNA as percent of total 14C in the tissues of 21 day old rats, injected with [14C]thymidine on 2nd day after birth, indicated the turnover (degradation) of DNA. The results showed that the DNA content of cerebellum as well as cerebrum was reduced by treatment with PCPA plus PHE, while treatment with alpha MPA plus PHE had no effect on DNA content in cerebellum but reduced the levels in cerebrum. Treatment with PCPA or alpha MPA plus PHE reduced the synthesis of DNA in cerebrum of 11 day old rats but not in 21 day old rats, and the treatments did not affect DNA synthesis in cerebellum of either 11 or 21 day old rats. The turnover (degradation) of DNA was increased in both cerebellum and cerebrum from rats treated with PCPA plus PHE but alpha MPA plus PHE treatment did not alter the DNA turnover either in cerebellum or in cerebrum. The activity of acid DNase was reduced in both cerebellum and cerebrum from 11 as well as 21 day old rats treated with PCPA plus PHE, but the enzyme activity was not altered in the tissues from rats of both ages treated with alpha MPA plus PHE. The data thus indicate that in rats treated with PCPA plus PHE the reduction in cerebral DNA levels occurs due to reduced synthesis and/or increased turnover (degradation) of DNA but that the reduction in cerebellar DNA may occur only as a result of increased turnover (degradation), and that in rats treated with alpha MPA plus PHE the reduction in cerebral DNA must occur due to reduced synthesis. This suggests that treatment of rats with PCPA plus PHE during suckling inhibits cell proliferation and/or increases naturally occurring cell death in both cerebellum and cerebrum while treatment with alpha MPA plus PHE inhibits only cell proliferation and in cerebrum alone.

Brain DNA metabolism in myelin deficient mutant jp, jpmsd and qk mice

We studied metabolism of brain DNA in three myelin deficient mutants qk, jp and jpmsd mice. The DNA content, the in vivo incorporation of [14C]thymidine in DNA and the activity of acid DNase in tissues (cerebellum and cerebrum) from normal littermates and affected mice were compared. The results showed that neither the DNA content, the incorporation of [14C]thymidine in DNA nor the activity of acid DNase in brain were altered in qk affected mice. In jpmsd mice, however, the DNA content as well as the incorporation of thymidine in DNA were reduced in both cerebellum and cerebrum, but the activity of acid DNase was reduced in cerebrum only. In jp mice, although the DNA content was reduced in both cerebellum and cerebrum, the incorporation of thymidine in DNA and the activity of acid DNase were reduced in cerebrum only. The data suggest a) that in qk mutants DNA metabolism and hence cell (glial) proliferation is not affected; b) that in jpmsd mutants DNA synthesis, and thus the cell proliferation is reduced in cerebellum as well as in cerebrum of the affected mice and c) that in jp mutants the synthesis of DNA and the cell proliferation is reduced in cerebrum but not in cerebellum.

Presynaptic tyrosine availability in the phenylketonuric brain: a hypothetical evaluation

From measured effects of amino acids on synaptosomal tyrosine uptake and from published data on human CNS levels of amino acids hypothetical calculations were made to compare CNS tyrosine availability for catecholamine synthesis in the hyperphenylalaninemic and non-hyperphenylalaninemic condition. These calculations indicate an approximately two-fold reduction in the availability of tyrosine in phenylketonuria that is due solely to a reduction in CNS tyrosine alone.