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Biomedical subjects

J Strauss

Publications and source records attributed to J Strauss.

At least 19 recordsLinked to original sources

Cytophotometric analysis of magnocellular azure B-RNA and Feulgen-DNA following chronic GABA infusion into the nucleus basalis of rats.

This investigation was undertaken to examine possible cytopathic effects of GABA infusion on nucleus basalis (NBM) magnocellular neurons. Sixty-three male Long-Evans rats received unilateral, intra-NBM infusions of either GABA100 (100 micrograms/microliters/h), GABA10 (10 micrograms/microliters/h), or ultrafiltered saline (1 microliter/h) for a period of 24 hours. Rats from each of these groups were sacrificed at either 24 hours, 48 hours or 8 days following initiation of infusions. The sham operated hemisphere of each rat served as a control for the infused hemisphere. After stoichiometric azure B-RNA and Feulgen-DNA staining of brain sections, scanning-integrating microdensitometry was used to quantify GABA-induced alterations in these well established indices of neuronal toxicity. These results provide evidence that the neurotoxic effects of 24 hours of 100 micrograms/microliters-h GABA infusion are manifested within 48 hours post-initiation of infusions. Although 24 hours of 10 micrograms/microliters-h GABA infusion suppressed NBM neuronal metabolism, the lower magnitude and duration of this effect signified an impending recovery. GABA infusion resulted in little if any NBM neuronal chromatin template impairment (i.e., reduced Feulgen-DNA reactivity), irrespective of the dosage employed and the delay prior to sacrifice.

Analysis of Variance

Hepatitis C infection in a pediatric dialysis population.

A variable prevalence of hepatitis C (HCV) infection has been reported in adult patients on hemodialysis. We have studied HCV infection and associated risk factors in a pediatric dialysis unit. Sera from all 27 patients undergoing either hemodialysis or peritoneal dialysis in our unit were tested for antibody to HCV by enzyme-linked immunosorbent assay, and seropositives were confirmed by recombinant immunoblot assay. Records were reviewed for demographic, biochemical, and risk factor data. From the total of 27 patients (12 male, mean age 20.9 years, range 7.3 to 28.1 years), five were anti-HCV(+) (18.5%). All the anti-HCV(+) patients had been on hemodialysis (69 to 194 months, mean 105 months), while of the 22 anti-HCV(-) patients, only 14 had been on hemodialysis (5 to 209 months, mean 41.4 months), P less than .005. All the anti-HCV(+) patients had received blood transfusions (10 to 124 units, mean 61.4 units) as had 12 of the anti-HCV(-) patients (1 to 54 units, mean 14 units), P less than .02. Of the 5 anti-HCV(+) patients, only one had prior hepatitis B infection; of the 22 anti-HCV(-) patients, three had hepatitis B surface antigen, and no others had evidence of hepatitis B infection. The most predictive risk factor for HCV infection was length of time on hemodialysis. Eleven of the 27 patients (40.7%) had abnormal alanine aminotransferase values, of whom four were anti-HCV(+), three were hepatitis B surface antigen(+), and one was seropositive for antibody to human immunodeficiency virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

[Sonographic screening of upper urinary tract obstruction and approach to its treatment].

Sonographic examination of the uropoietic tract (UPT) in neonates makes it possible to detect in time inborn disorders, in particular of the excretory pathways and to provide treatment before irreversible changes develop. The authors subject within the framework of screening of inborn developmental defects all neonates to sonographic examination of the UPT. In the submitted paper they evaluate a group of 2,103 children in the course of a one-year period; 89 neonates had changes as compared with normal findings. The largest group is formed (by as many as 57) by marginal dilatation of the hollow space. A dilated hollow system was recorded in 24 neonates and eight had different types of anomalies. By further comprehensive investigation conservative or surgical procedure is indicated to prevent further, possibly irreversible damage of the renal parenchyma.

Constriction, Pathologic

[Preoperative blood alcohol levels in patients hospitalized for prolonged surgical procedures].

Self medication using anxiolytic and relaxing agents prior to surgery is a common phenomen in many patients. In our prospective study of 356 patients undergoing prolonged surgical procedures (greater than 3 h), we evaluated the preoperative ethanol level of the blood using gas-chromatography. In 39 (10.9%) of 307 tumor patients ethanol could be detected in high concentrations, indicating the ingestion of disinfectants. Among our 49 orthognathic cases blood alcohol was found in 4 cases (8.2%). Since the minimum effective dose for ethanol ist 0.1 to 0.2 g/l, the patients' legal capacity when giving informed consent for surgery and anesthesia is to be questioned and the risks of analgosedation in outpatient must be considered.

Alcoholic Intoxication

[Differential indication of tracheotomy in oral and maxillofacial surgery].

In the hospital for Oral and Maxillofacial Surgery at the Medical University Hannover 105 tracheostomies were performed between 1980 and 1990. We see a limited indication for a general prophylactic tracheotomy in patients with ablative surgery and microvascular reconstructive procedures. The indication for tracheotomy must be considered in each individual case.

Airway Obstruction

nirA, the pathway-specific regulatory gene of nitrate assimilation in Aspergillus nidulans, encodes a putative GAL4-type zinc finger protein and contains four introns in highly conserved regions.

The nucleotide sequence of nirA, mediating nitrate induction in Aspergillus nidulans, has been determined. Alignment of the cDNA and the genomic DNA sequence indicates that the gene contains four introns and encodes a protein of 892 amino acids. The deduced NIRA protein displays all characteristics of a transcriptional activator. A putative double-stranded DNA-binding domain in the amino-terminal part comprises six cysteine residues, characteristic for the GAL4 family of zinc finger proteins. An amino-terminal highly acidic region and two proline-rich regions are also present. The nucleotide sequences of two mutations were determined after they were mapped by transformation with overlapping DNA fragments, amplified by the polymerase chain reaction. nirA87, a mutation conferring noninducibility by nitrate and nitrite, has a -1 frameshift at triplet 340, which eliminates 549 C-terminal amino acids from the polypeptide. Under the assumption that the truncated polypeptide is stable, it comprises the zinc finger domain and the acidic region, which seem not sufficient for transcriptional activation. nirAd-106, an allele conferring nitrogen metabolite derepression of nitrate and nitrite reductase activity, includes two transitions, changing a glutamic acid to a lysine and a valine to an alanine, situated between a basic and a proline-rich region of the protein. Northern (RNA) analysis of the wild type and of constitutive (nirAc) and derepressed (nirAd) mutants show that the nirA transcript does not vary between these strains, being in all cases constitutively expressed. On the other hand, transcript levels of structural genes (niaD and niiA) do vary, being highly inducible in the wild type but constitutively expressed in the nirAc mutant. The nirAd mutant appears phenotypically derepressed, because the niaD and niiA transcript levels are overinduced in the presence of nitrate but are still partially repressed in the presence of ammonium.

Amino Acid Sequence

Clinical management of the pediatric renal-allograft recipient.

Management of the pediatric renal-transplant recipient requires careful pretransplant evaluation including psychosocial assessment and cautious donor/recipient selection. Early transplantation is preferable in infants less than 1 year of age if a suitable live-related donor is available. However, cadaveric-allograft transplantation is best reserved for patients older than 3 years with donors older than 5 years. Pre-emptive transplantation is suitable for approximately one fifth of the population. Medical preparation includes careful HLA-A, -B, and -DR loci matching, interferon treatment for positive hepatitis antigenemia, and acyclovir prophylaxis for a cytomegalovirus (CMV) antibody-negative patient to a seropositive donor. Postoperative management requires close monitoring of the patient's volume status with careful fluid replacement in the form of colloid and crystalloid. Immunosuppression involves multiple drug regimens that include corticosteroids, ciclosporin, azathioprine, antilymphocyte (or -thymocyte) globulin (ALG/ATG), monoclonal antibodies (OKT3), and a ciclosporin alternative: FK-506. Long-term complications dictate management and are divided into medical, surgical, immune, and infectious categories. These are predominated by treatment of acute and chronic rejection, hypertension, and CMV infection.

Blood Transfusion

[Loss of maternal measles antibodies acquired by vaccination against measles].

The objective of the investigation was to assess whether children of mothers who acquired measles antibodies resp. immunity by vaccination are at least for the first six months of their life protected by maternal antibodies. A group of fifty pregnant women mean age 18 years incl. their umbilical blood and blood of their children, mostly 5-6 months after birth, were examined by the haemagglutination inhibition and immunoenzymatic test. The levels of measles antibodies were detected in 11 women immunized against measles in cca 1970 and in 26 revaccinated women mostly after 5 to 11 years. In once vaccinated mothers and their umbilical bloods the mean HI titres were 1:8.5 and 1:14 resp. and the mean EIA titres were 1:3600 and 1:3040 resp. As to the eight newborn children at the age of 5 and 6 months 6 children did not have any protective antibodies. In twice vaccinated women and their umbilical bloods the mean HI titre was 1:10 and 1:16.4 resp. and EIA titres were 1:2937 and 1:3784 resp. Of the 15 newborn infants at the age of 4 to 6 months 11 infants did not have any protective antibodies. In 8 mothers without vaccination records and their umbilical bloods the mean HI titre was 1:7.5 and 1:25.5 and mean EIA titres were 1:8229 and 1:7360 resp. In none of their children at the age of 6 months measles antibodies were found. The finding of the lack of protection in children older than 6 months stimulates further research of the problem.

Antibodies, Viral

[Osteolytic forms of rheumatoid polyarthritis. Personal cases and review of the literature].

The authors report eight personal cases of severe and multiple osteolysis in rheumatoid arthritis. 42 other cases were found in the international literature. Osteolytic rheumatoid arthritis concern almost exclusively women, often with small stature. Lesions prevail on upper limbs. All peripheric joints can be involved, except knees, ankles and tarses. The most typical and the most constant aspect is the "opera glass hands". Extra-articular manifestations occur in the same rate as for common rheumatoid arthritis. Rheumatoid factor are present in 2/3 of the cases. Pathogeny of these osteolyses remains unknown and a neurologic mecanism is inprobable.

Aged

[Urogenital chlamydial infection in men and their sexual contacts].

Cultivation and serological tests for Chlamydia trachomatis were made in a total of 39 male patients (24 married, 11 single, 3 divorced, 1 widower) and their female partners (9 extra-marital, 12 wives) on average 35 years old in both groups. Apart from the clinical diagnosis of non-specific urethritis found in all male patients, 11 patients suffered from other infections (5 from balanitis, 4 from prostatitis, 1 from prepuce infection, 1 from herpetic infection) and subjective disorders. Side by side with clinical diagnosis of cervicitis or in combination with urethritis found in 16 female sexual partners, two of them suffered also from vulvovaginitis, 2 from adnexitis, 1 from candidosis, 1 had dysuric difficulties and 1 female patient was found sterile. 11 women had no subjective problems. The cultivation-tinction technique used in 25 men (14 married, 11 single) and 14 female sexual partners respectively (8 marital and 6 extramarital), positive Chlamydia trachomatics was isolated 21 times (84%) and 9 times (64.3%) respectively. The immunofluorescence technique using monoclonal antibodies applied to 39 men (24 married, 15 single) and 21 female sexual partners respectively, (i. e. 12 marital and 9 extramarital) gave positive results in 29 cases (74.4%) and 16 persons (76.2%) respectively. One patient was homosexual with a positive finding in the urethra and rectum, and, in addition, he was found to have BWR positive with Candida albicans and group B streptococci, however, his serological HIV was negative. The immunoenzymatic test (EIA) showed borderline titres as being positive in men in 28.2% cases and women in 26.3% and high levels (1:128+) in 41.0% in male patients and 21.1 percent in female patients respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Chlamydia Infections

Enhancement of SIV infection with soluble receptor molecules.

The CD4 receptor on human T cells has been shown to play an integral part in the human immunodeficiency virus type 1 (HIV-1) infection process. Recombinant soluble human CD4 (rCD4) was tested for its ability to inhibit SIVagm, an HIV-like virus that naturally infects African green monkeys, in order to define T cell surface receptors critical for SIVagm infection. The rCD4 was found to enhance SIVagm infection of a human T cell line by as much as 18-fold, whereas HIV-1 infection was blocked by rCD4. Induction of syncytium formation and de novo protein synthesis were observed within the first 24 hours after SIVagm infection, whereas this process took 4 to 6 days in the absence of rCD4. This enhancing effect could be inhibited by monoclonal antibodies directed to rCD4. The enhancing effect could be abrogated with antibodies from naturally infected African green monkeys with inhibitory titers of from 1:2,000 to 1:10,000; these antibodies did not neutralize SIVagm infection in the absence of rCD4. Viral enhancement of SIVagm infection by rCD4 may result from the modulation of the viral membrane through gp120-CD4 binding, thus facilitating secondary events involved in viral fusion and penetration.

Animals

Quantitation of proteinuria with urinary protein/creatinine ratios and random testing with dipsticks in nephrotic children.

We examined the relative feasibility of using random urinary dipstick testing and urinary protein/creatinine ratios in the quantitation of proteinuria. Sixty-four children with relapsing nephrotic syndrome, ranging in age from 1 1/2 to 16 years, contributed 145 timed urine collections and 150 random specimens, which were analyzed by urinary protein dipstick, quantitation of protein and creatinine, or both. Total protein excretion was expressed as grams per surface area per day and the urinary protein/creatinine ratio as milligrams of protein per milligram of creatinine. Degrees of proteinuria were designated as physiologic (less than 0.1 gm/m2/day), intermediate (greater than 0.1 and less than 1.0 gm/m2/day), or nephrotic (greater than 1.0 gm/m2/day). The log regression analysis of the 24-hour urinary protein/creatinine ratio (y) and total protein excretion (x) was highly significant (r = 0.97; p less than 0.001). The upper and lower confidence limits of the urinary protein/creatinine ratio (1.0 and 0.1, respectively) closely approximated the designations for nephrotic and physiologic proteinuria, respectively. These values were therefore used to classify degrees of proteinuria by the urine protein/creatinine ratio. The validity of these tests was assessed by sensitivity, specificity, and predictive value, and compared with that of random testing by urinary dipstick. The urinary protein/creatinine ratio offered good reliability as a test for classifying degrees of proteinuria and accurately predicting nephrotic and physiologic proteinuria. The random dipstick testing was reliable only when results were distinctly positive and when sensitivity and specificity were low. The error in the total protein excretion value that was imposed by collection errors with high and low variations in the creatinine value (57% of samples) was largely corrected by normalization of the data by log transformation. When controlled for creatinine excretion, linear regression analysis allowed calculation of total protein excretion (TP) from the urinary protein/creatinine ratio (U P/Cr) by the following equation: TP (gm/m2/day) = 0.63 (U P/Cr) at all levels of proteinuria. The random urinary protein/creatinine ratio appeared to offer the most sensitive test for classification of proteinuria in children with nephrosis, with the advantages of ease and expediency not afforded by the 24-hour urine quantitation.

Adolescent

Effects of methylphenidate on processing negativities in patients with attention-deficit hyperactivity disorder.

This study compared the impact of methylphenidate on patients with Attention-deficit Hyperactivity Disorder (ADHD) with and without aggressive/noncompliant features in an oddball test consisting of a randomly ordered series of loud (frequent) tones, soft (rare) tones, bright (frequent) lights, and dim (rare) lights. In alternate conditions, subjects were required to respond to either the rare tones or the rare lights. These tasks were administered in a drug-free baseline session and after a counterbalanced treatment of 14 days each of methylphenidate (0.3 mg/Kg b.i.d.) and placebo (lactose b.i.d.). In comparison with placebo, methylphenidate resulted in greater accuracy and speed of reactions to targets of both modalities. The amplitude of N1 to auditory nontargets was larger when the target was a rare tone as opposed to a rare light, and this attention-related effect was increased by methylphenidate. The same differential amplitude enhancement by stimulant treatment was found for an early area measure of difference ERPs. In contrast, for N1 to visual nontargets the effect of selective attention (larger amplitude when the target was a rare light vs. a rare tone) was not significant and was not affected by stimulant medication. All these findings were comparable for the three ADHD subgroups, a result attesting to the generality of stimulant effects on information processing.

Arousal

Renal disease in children with the acquired immunodeficiency syndrome.

Of 155 children with the acquired immunodeficiency syndrome (AIDS) whom we evaluated during a 6 1/2-year period, 12 were found to have proteinuria. Histologic studies of tissue from these 12 patients revealed a wide spectrum of renal disease: focal glomerulosclerosis in 5, mesangial hyperplasia in 5, segmental necrotizing glomerulonephritis in 1, and minimal change disease in 1. In addition, 6 had tubulointerstitial infiltrates, and 10 had glomerular dense deposits. All 10 renal specimens studied by electron microscopy contained endothelial tubuloreticular inclusions. The mean age (+/- SD) of the five patients with focal glomerulosclerosis when this condition was identified was 27 +/- 19 months. All five had severe renal failure within a year and died of other causes during the following year. The mean age of the five patients with mesangial hyperplasia was 38 +/- 31 months. Although none of them went on to have renal failure, four died within 8 +/- 7 months. Ten of the 12 patients with proteinuria died during the study period. Of the two surviving, one had mesangial hyperplasia and the other had minimal change disease. We conclude that children who acquire human immunodeficiency virus (HIV) infection during the perinatal period may have renal disease, most often focal glomerulosclerosis, as is the case in adults, or mesangial hyperplasia. Although 5 of the 12 children we studied had renal failure during the study period, none died of it. Further studies are needed to determine the correlations between clinical and pathological features and the pathophysiology of AIDS nephropathy in children.

Acquired Immunodeficiency Syndrome