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Biomedical subjects

N Strauss

Publications and source records attributed to N Strauss.

At least 37 records · Page 2Linked to original sources
PubMed1991

Immune response to polio vaccination in bone marrow transplant recipients.

Following a small outbreak of poliomyelitis which occurred in the summer of 1988 in Israel, two sequential doses of inactivated polio vaccine (IPV) were administered to 42 bone marrow transplant (BMT) recipients (aged 2-50 years) who were 6-96 months (median 16 months) after transplantation. Prior to vaccination, only 68-80% patients (n = 42) had protective (greater than or equal to 4) antibody levels against the three serotypes of poliovirus, compared with 92-96% (n = 25) before BMT (p = 0.02 for types 1 and 3). After the second dose of IPV, 89-98% (n = 27) of the recipients had protective antibody levels. The pre-vaccination antibody titers were lower than before BMT (p = 0.006, 0.0007 and 0.0008 for types 1,2 and 3, respectively). After the first dose of IPV, antibody titers rose in the 42 patients (p = 0.002, 0.043 and 0.002 for types 1, 2 and 3, respectively) and following the second dose, a further increase in antibody levels was noted. Regression analysis revealed that graft-versus-host disease, pre-BMT polio antibody titers, age and type of transplantation (allogeneic versus autologous) were significant explanatory variables for the specific antibody levels, while the time lapse between BMT and vaccination, and primary disease proved of no significance. Vaccination against poliovirus after BMT is advocated, as it reinstates and raises the lost specific humoral immunity.

Adolescent↗
PubMed1991

Hyponatremia induced by exercise: a 24-hour endurance march study.

In our previous studies on the relationship between prolonged physical stress and muscle enzyme activities, a number of individuals suffered a hyponatremic state. The present study was conducted to evaluate the effect of prolonged physical stress on the development of hyponatremia. Seventeen physically fit male subjects were studied during a 24-hour endurance march. Serum sodium, that averaged 142 +/- 2 before the march, decreased during the march to 135 +/- 2 mEq/l (p less than 0.01 versus before the march). Blood and plasma volumes increased by 8 and 16% (p less than 0.05), respectively. Creatinine clearance before the march declined from 118 +/- 24 to 74 +/- 19 ml/min (p less than 0.005) during the march and correlated negatively with serum sodium (p less than 0.002; r = 0.59). Urinary sodium excretion before the march was 132 +/- 55 and during the march was 123 +/- 62 mEq/24 h. Free water clearance rose during the march and correlated negatively with serum sodium (p less than 0.001), suggesting an appropriate renal diluting response. However, the fall in serum sodium correlated positively with water intake (p less than 0.01; r = 0.59). These results show that hyponatremia develops during endurance marching in normal subjects on an unrestricted high water intake. The renal response to water intake is appropriate; however, the subjects fall to produce maximally diluted urine. Therefore, we suggest that water intake should follow physiological needs and not forced to cause hyponatremia during prolonged physical stress.

Adult↗
PubMed1989

Molecular packing in profilin: actin crystals and its implications.

Analysis of profilin: actin crystals reveals an extensive intermolecular network, rather than a discrete "monomeric complex", comprising stacked actin ribbons held in place by columns of profilin molecules, wedged in between neighboring actin subunits and running perpendicular to the ribbons. Comparison with data from electron microscopy, X-ray diffraction, spectroscopy, and biochemistry of actin suggests that a simple transformation relates the ribbon to f-actin. The crystals exhibit unusual polymorphic properties, which strengthens the view that movements within the actin monomer are important for force generation.

Actins↗
PubMed1989

Randomised study of myringotomy, amoxycillin/clavulanate, or both for acute otitis media in infants.

In a prospective study, 105 infants aged 3-12 months with acute otitis media were randomly assigned to one of three treatment groups: amoxycillin/clavulanate ('Augmentin') alone (36 patients), myringotomy plus placebo (35 patients), or augmentin plus myringotomy (34 patients). The last two groups were double-blinded. Bacterial pathogens, mainly Haemophilus influenzae (of which 20% were beta-lactamase producers) and Streptococcus pneumoniae, were isolated from 60% of the ear exudates and all isolates were sensitive to augmentin. Most of the infants improved clinically within 3-6 days irrespective of the treatment protocol. As judged by otoscopy, 60% of the patients receiving augmentin, with or without myringotomy, recovered completely compared with 23% of patients treated with myringotomy plus placebo. Treatment with augmentin was also more effective than myringotomy with regard to persistence of ear infection. In the myringotomy plus augmentin group closure of the incision and resolution of the discharge from the incision site was faster than in the myringotomy plus placebo group. The addition of myringotomy to augmentin did not seem to affect either the persistence of the infection after treatment or the residual middle ear effusion.

Acute Disease↗
PubMed1989

Asymptomatic giardiasis in children.

Giardia lamblia infection was identified in 33 of 89 (37%) 3-month-old to 3-yr-old children who were followed with monthly stool examinations for up to 12 months in a day care center. The infection was mainly asymptomatic and usually associated with prolonged carriage of the parasite. There were no significant differences for height and weight achievements and mean hemoglobin values between Giardia-positive and Giardia-negative children. However, Giardia-positive children tended to achieve higher weight and height for age than Giardia-negative children; weight for age was above the 50th percentile in 69% of Giardia-positive vs. 40% of Giardia-negative children (alpha = 0.01). Giardia-positive children tended to have fewer symptoms related to the gastrointestinal and respiratory tracts as recorded by a weekly questionnaire. Lactase deficiency was detected by breath hydrogen testing in 8 of 26 Giardia-positive vs. only 1 of 21 Giardia-negative children (P less than 0.02). Healthy day care children with asymptomatic Giardia infection show no disadvantage and perhaps even an advantage in nutritional status and freedom from other illnesses.

Body Height↗
PubMed1979

A biological approach to two forms of human self-injury.

One hundred cases of self-injury, comprising 39 self-cutters and 61 self-poisoners, were interviewed when they became able to describe the act: 83 in a casualty department, 17 in a hospital. Standardized recordings were made of their feeling state before and after the act, together with an account of the social circumstances under which it occurred. The information was obtained in a way which allowed comparison with existing animal data on self-injury, although comparisons were made between what is known of animal behavior in this area and human feelings as reported by these subjects. The results indicate similarities between what is known of animal self-injury and self-cutting in man in the form of the injury, in the social situation preceding the act, and in the agitation preceding it. Similarities also exist, but are less close, for the self-poisoners. The most obvious effect of the act is a reduction in tension; this may constitute its physiological value.

Adolescent↗
PubMed1975

Characterization of a rifampin-resistant, conditional asporogenous mutant of Bacillus subtilis.

A rifampin-resistant, conditionally asporgoenous mutant of Bacillus subtilis was isolated that sporulates poorly in Sterlini-Mandelstam sporulation medium, but that sporulates normally in modified Difco sporulation medium. Rifampin-resistant (Rif-r) and conditional asporogenous (Spo-c) phenotypes co-transformed at 100% frequency. Preliminary genetic studies indicated the Rif-r trait to lie between cysA14 and ery, a locus (rnp) common to Rif-r mutants. Ribonucleic acid polymerase from strains bearing this mutation was found to be rifampin resistant in vitro. The loss of ability to sporulate in Sterlini-Mandelstam medium was found to be corrected, to a large extent, by addition to the medium of arginine, methionine, valine, and isoleucine. Several other amino acids had small effects, whereas others had no effect at all. The restorative effect is approximately additive. Growth studies indicated that Rif-r strains grew more rapidly than the corresponding parent in minimal medium at temperatures higher than 37 C. Addition of certain amino acids to the medium resulted in identical growth rates at these temperatures. Extracellular protease and esterase activities of the Rif-r Spo-c mutant were normal. A slight difference was found in the heat sensitivity of partially purified ribonucleic acid polymerase preparations of this mutant compared to the wild type.

Animals↗
PubMed1970

Early energy-dependent step in the entry of transforming deoxyribonucleic acid.

It was found that cyanide can partially reverse as well as arrest the transformation of a newly transformed deoxyribonuclease-treated culture for 6 to 8 min after the addition of the enzyme. These findings strongly suggest that deoxyribonucleic acid which attained deoxyribonuclease-insensitivity is not necessarily in the cell, but stored in some region peripheral to the membrane, and that a rate-limiting, energy-dependent step is required to transport this deoxyribonucleic acid into the cell.

Bacillus subtilis↗
PubMed1969

Regulation of synthesis of glutamine synthase in Bacillus subtilis.

A study of the regulation of the synthesis of the enzyme glutamine synthase in Bacillus subtilis was initiated. An assay, based on the measurement of glutamo-hydroxamate, was used to characterize the enzyme in crude preparations and in toluene-treated cells. Determinations were made of the Michaelis constants for adenosine triphosphate, hydroxylamine, and glutamate (9 x 10(-3), 4 x 10(-3), and 2.2 x 10(-2)m, respectively), the pH optimum (7.6 to 7.7), and the stability. The differential rate of synthesis was determined under various growth conditions. The enzyme was found to be relatively insensitive to regulation. Partial repression was caused by glutamine, arginine, asparagine, and glutamate, or by carbon limitation in a chemostat. Derepression was caused by exhaustion of externally added amino acids or by nitrogen limitation in a chemostat.

Adenosine Triphosphate↗
PubMed1966

Further evidence concerning the configuration of transforming deoxyribonucleic acid during entry into Bacillus subtilis.

Strauss, Norman (State University of New York at Buffalo, Buffalo, N.Y.). Further evidence concerning the configuration of transforming deoxyribonucleic acid during entry into Bacillus subtilis. J. Bacteriol 91:702-708. 1966.-The appearance of linked, unselected traits with selected markers was followed as a function of time after the exposure of competent cells to transforming deoxyribonucleic acid (DNA). It was found that the per cent cotransfer of a linked, unselected trait with a single selected trait increased sharply soon after the lag period characterizing the appearance of the selected trait. Similar results were obtained when cotransfer of a linked unselected trait with a pair of selected traits was examined. The results are taken as an unequivocal demonstration that the entry of transforming DNA into competent Bacillus subtilis occurs in longitudinal fashion. The nature of the linkage between try(2) and his(9) was characterized. It was found that, although these two traits had been found to be unlinked on the basis of recombination tests, the saturation curves showed these two traits to be present on the same fragment of DNA.

Bacillus subtilis↗
PubMedDate not supplied

Transplantation performance of human skin cryopreserved by programmed or stepwise freezing and stored at -80 degrees C or -180 degrees C.

We developed a mouse recipient model that was used to evaluate and compare four cryopreservation procedures for human cadaveric skin stored for two time periods. Skin specimens were identically processed and preserved by programmed (1 degree C/min), or stepwise freezing, and stored at -180 degrees C or -80 degrees C for periods of 1 month and 6 to 10 months. Samples were grafted on Balb/c mice, and primary take was evaluated after 7 days. The results indicate that although all grafted specimens were initially accepted, as indicated by gross observations, histologic differences were evident and significant. The study groups were analyzed for the effect of method and skin sample variety; the effect of freezing procedure and temperature level; time effect (storage period); and advantage of method 1 (programmed freezing at -180 degrees C) over the other methods. The significance (p value) was determined for separate histologic criteria and average skin score or quality. The overall results indicate that average score of skin preserved by method 1 is highest for both storage periods. This method has an almost significant advantage (p = 0.057) over the others on quality of skin stored for 1 month, and a highly significant advantage (p = 0.007) on graft adherence of skin stored for 6 to 10 months. The effect of method and samples variety on the separate histologic criteria and average score of skin is not always significant. However, an interaction factor (between method and samples) has a highly significant effect (p < 0.001) on almost all of the histologic criteria and average skin score. The effects of freezing method is significant only on average skin score, for 1 month of storage; whereas temperature effect is seldom significant. Evaluating the effects of time, samples, and the interaction factor (between time and samples) indicated that the interaction factor is highly significant (p < 0.001). Time and samples effects are rarely significant. Thus the quality of the final product-the cryopreserved skin-is determined by many factors, and quite often they interact. Highly significant is the combined effect, or interaction factor, of sample variability with method of cryopreservation or with storage period.

Animals↗