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Biomedical subjects

J Strauss

Publications and source records attributed to J Strauss.

At least 253 records · Page 14Linked to original sources
PubMed1965

Electrical impedance of isolated amnion.

The electrical impedance of the guinea pig amniotic membrane was measured, under standardized conditions, over the frequency range of 20 to 7000 cycles/second. This impedance can be represented analytically by a simple frequency-dependent function which is precisely of the form of the Debye relaxation equation. The observed data exhibit a broad dispersion centered at a frequency of 1050 cycles/second and a narrow distribution of time constants centered about 152 microseconds, both effects being due to the polydisperse nature of amniotic tissue. If the narrow time-constant distribution is approximated by a single time constant, amnion impedance can be simulated by a simple electrical circuit of frequency-independent elements. The Maxwell-Wagner interfacial treatment, although successfully adapted for cell suspensions, is shown to lose its quantitative significance in the case of the tightly structured amnion. In addition, determinations were made on the chemical composition of amniotic fluid, fetal blood and urine, and maternal blood and urine; the DC potential across the amniotic membrane was also measured.

Amnion↗
PubMed1965

Comparative trial of live measles vaccines in Czechoslovakia.

The study reported in this article was conducted under the auspices of WHO as part of the Organization's programme on measles vaccination.In the spring of 1964, 416 children aged between 8 months and 3 years were inoculated with one or another of the following agents: Enders Edmonston B vaccine (alone or with gamma-globulin), Schwarz vaccine, Beckenham 20 vaccine, Milovanović vaccine, and a placebo.Seroconversion rates ranged from 91% to 100%, which indicates that the vaccines tested were highly immunogenic. The incidence of reactions was low, and from the clinical point of view acceptable. Clinical comparison of the reactions provoked by the different vaccines showed that the lowest rate was in the groups given Schwarz vaccine and Enders Edmonston B plus gamma-globulin, and the highest in the group given Beckenham 20 vaccine. However, the greater frequency of reactions observed with Beckenham 20 vaccine might have been due to the high dose given in the first stage of the trial.Complications were observed in 10 children, of whom four were in the placebo group. In three of the remaining cases a causal connexion with the vaccine could not be excluded with certainty.

Child, Preschool↗
PubMedDate not supplied

[False hyperphosphoremia in multiple myeloma. Interference of monoclonal immunoglobulin G with the determination of blood phosphorus level].

A case of pseudohyperphosphataemia detected in a male patient with multiple IgG myeloma is reported. Phosphataemia, measured by a technique without previous deproteinization, reached 5.66 mM before any treatment and varied with treatment-induced changes in monoclonal immunoglobulin levels. Conversely, normal phosphataemia levels were found in blood samples taken before and after treatment when serum was deproteinized. This pseudohyperphosphataemia resulted from an increase in optic density due to interference between monoclonal immunoglobulin and the molybdic reagent used to determine phosphataemia. A retrospective investigation yielded three similar cases: two in patients with myeloma and one in a patient with non-myelomatous monoclonal dysglobulinaemia. A brief prospective study showed that this phenomenon was relatively frequent, as it was found in 2 out of 9 patients with monoclonal immunoglobulin (IgG in all 9 cases). These data indicate that the finding of marked hyperphosphataemia in subjects with monoclonal dysglobulinaemia should always prompt a control assay performed on deproteinized blood.

Electrophoresis↗
PubMedDate not supplied

Validation of rat endometriosis model by using raloxifene as a positive control for the evaluation of novel SERM compounds.

Approximately 10% of women of reproductive age suffer from endometriosis, a potentially painful disease process and important cause of female infertility. Raloxifene, a commercially available SERM (selective estrogen receptor modulator) compound, used for the treatment of postmenopausal osteoporosis, has preclinically demonstrated its estrogen antagonist effect on uterine tissue in rats. There is potential that SERM compounds may become a viable treatment option for human endometriosis, although more investigation is needed. In this study, raloxifene was administered at various doses to determine the efficacy and an appropriate dose level for use as a positive control in a rat model of endometriosis. Prior to dose administration, all rats underwent a bilateral ovariectomy, autologous transplantation of uterine tissue onto the peritoneal surface of the abdominal wall, and implantation of a subcutaneous estrogen pellet (E2). Two separate postsurgical experiments were performed. In experiment 1, following a 4-wk recovery, the rats bearing implants were assigned to three groups: (1) removal of the E2 pellet and dosing vehicle only (n = 7); (2) E2 and vehicle (n = 6); and (3) E2 and raloxifene at 10.0 mg/kg (n = 6). In experiment 2, also following a 4-week recovery, the rats bearing implants were assigned to five groups (n = 8/group): (1) E2 and vehicle only; (2) E2 and raloxifene, 0.3 mg/kg/d; (3) E2 and raloxifene, 1.0 mg/kg/d; (4) E2 and raloxifene, 3.0 mg/kg/d; (5) E2 and raloxifene, 10.0 mg/kg/d. All rats were dosed orally BID for 14 d. At the end of the study, the implanted endometrium was remeasured and compared to the pretreatment measurement. The results from both studies demonstrated that Raloxifene at only one dose (10.0 mg/kg) displayed significant implant regression (p < .05). Subsequently, our rat endometriosis experimental model consistently uses the exogenous E2 pellet and raloxifene at 10 mg/kg, BID, as a positive control to help screen and compare novel SERM compounds.

Animals↗
PubMedDate not supplied

An improved trace analysis for N-nitrosoureas from biological media.

1,3-Bis(2-chloroethyl)-1-nitrosourea, BCNU, a widely used anticancer agent for a variety of neoplasms, can be rapidly, conveniently, and inexpensively determined at trace levels of clinical importance, from a variety of biological media, using HPLC-UV approaches. Limits of detection for BCNU from patient and control samples have been compared for HPLC-UV, HPLC-EC, and the Griess Test. The distribution and disappearance of BCNU from blood samples can be quickly and easily determined using the methods described. Individual blood samples are completely analyzed in less than 30 mins, from the time of sampling to qualitative and quantitative results.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Menstrual cycle abnormalities and subclinical eating disorders: a preliminary report.

Menstrual dysfunction is a common concomitant of anorexia nervosa and bulimia. Initial investigations emphasized the role of weight loss and lean/fat ratio in amenorrhea. Subsequent studies suggest a more complex interaction between eating disorders and menstrual status. However, in past investigations, menstrual abnormalities have been confounded with low weight. We conducted two studies to ascertain the prevalence of menstrual abnormalities in a group of women with subclinical eating pathology versus an age-, education-, and weight-matched group of normal controls. In Study I, 93.4% of the subclinical subjects reported a history of menstrual abnormality as compared to 11.7% of the normal controls. In Study II, 100% of the subclinical subjects, versus 15.0% of the controls, reported an abnormal menstrual history. These data suggest that menstrual dysfunction often occurs in women with abnormal eating attitudes but without weight loss or diagnosable eating pathology. Several hypotheses for this finding are proposed.

Adolescent↗
PubMedDate not supplied

Use of a soft catheter for acute peritoneal dialysis in infants and children.

Acute peritoneal dialysis in 49 infants and children is described comparing the use of the conventional hard Trocath catheter and the soft catheter. The mean age of the patients was 3.6 years (range 1 day--17 years). Sixteen were treated using the hard Trocath catheter and 33 were treated using a soft catheter. Overall mortality for the total patient population was 43%. Twenty-three neonates were included in the series with an overall mortality of 61%. Significantly less mortality was observed in the 26 patients older than two months of age (31%). Major complications of the dialysis procedure included viscus perforation in three neonatal patients and subcutaneous extravasation of dialysate in two older patients. These major complications occurred only with the use of the Trocath. Two episodes of peritonitis occurred in two adolescent patients and were associated with an interruption of the sterile system. Peritonitis was not specifically related to the type of catheter used. We conclude that major complications associated with the use of the hard catheter for peritoneal dialysis in neonates precludes its continued use in this population. The alternative use of a soft catheter is recommended in neonates. Elective use of a soft catheter for acute peritoneal dialysis in older patients would also seem to be indicated.

Abdominal Injuries↗