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Biomedical subjects

S Friedman

Publications and source records attributed to S Friedman.

At least 325 records · Page 18Linked to original sources
PubMed1987

Toxocara canis infection of children: epidemiologic and neuropsychologic findings.

Sera from 4,652 children whose blood was submitted to the New York City Department of Health for lead analysis were tested for antibodies to Toxocara canis using an enzyme-linked immunosorbent assay (ELISA). Standardized to the age distribution of the study population, T. canis seropositivity (inverse titers greater than or equal to 16) was 5.7 per cent in males and 5.1 per cent in females. T. canis antibody titers and lead exposures as measured by Centers for Disease Control lead classes were positively correlated. Children who were seropositive to T. canis (cases) were compared to seronegatives (controls) matched on age (+/- 6 months), sex, time-of-screening (+/- 3 months) and CDC lead class. Logistic regression analysis of 155 case-control pairs demonstrated elevated relative risks (RRs) for geophagia (RR = 3.14; 95% CI = 1.75, 5.64) and having had a litter of puppies in the home (RR = 5.22; 95% CI = 1.63, 16.71). Compared to controls, cases had increased eosinophil counts, serum immunoglobulin E concentrations, and anti-hemagglutinin-A titers. Small deficits in cases compared to controls were found in performance on several neuropsychological tests after adjustment for potential confounders including case-control differences in race, socioeconomic status, and current blood lead concentrations. The study thus confirmed that T. canis infection is common in urban children and suggested that infection may be associated with adverse neuropsychological effects.

Adolescent↗
PubMed1987

Effect of prenatal ethanol exposure on the growth of rat mandible skeletal units.

To study the effect of prenatal ethanol exposure on the growth of the skeletal units of the rat mandible, female Sprague-Dawley rats weighing 220-240 g were assigned to 1 of 3 different groups. One of the groups received ethanol in the drinking water (up to 10% v/v) for at least 15 days prior to mating, then 20% (v/v) throughout gestation. A balanced diet was supplied ad libitum. A second group was pair-fed with the first group. In addition, an amount of corn starch calorically equivalent to the amount of ethanol consumed by that group was offered. The remaining group formed the normal control and received food and water ad libitum. All groups were offered food and water ad libitum after delivery. Total caloric intakes in the first 2 groups. were 67.8% of that of the normal control group. The average off-spring weight at birth for rats given ethanol was 17% lower than that of normal control rats. There was no significant difference between the average weights of the offspring of pair-fed and normal control rats. During the ensuing 3 weeks, the weight of the offspring of alcoholic rats showed no indication of catching-up. All skeletal units of the mandible of the offspring of ethanol-treated females differed significantly from those of the control group. These differences varied between 2% and 16%. The skeletal units of mandibles of the pair-fed group did not differ significantly from ad libitum controls. The mandibular width was similar in all 3 experimental groups.

Animals↗
PubMed1987

Pontiac fever outbreak associated with a cooling tower.

In late April 1984, an outbreak of Pontiac fever was investigated in an office building in lower Manhattan (New York City). The outbreak was characterized by a high attack rate (78 per cent overall); the predominant symptoms were myalgias, chills, fatigue, fever, and headache. There was a clustering of cases in an office that was air cooled by a dedicated cooling tower separate from the remainder of the building. A high concentration of live L. Pneumophila cells in the cooling tower was quantified. Airborne spread via settle plates placed along the air intake system and within the office was demonstrated. Legionella pneumophila serogroup 1 antigen was found in the urine of two cases, and identical monoclonal antibody reactivity patterns of isolates from all sources was observed. Difficulty was experienced in eliminating the organism from the tower.

Adult↗
PubMed1986

Binding of the EcoRII methylase to azacytosine-containing DNA.

Binding of DNA(cytosine-5)methyltransferases to azacytosine containing DNA is stimulated by the presence of S-adenosyl-methionine or its analogs sinefungin or S-adenosyl-L-homocysteine. Methylation of the DNA is therefore not necessary for binding to occur. There is no relationship between the affinity of the analog for the EcoRII enzyme and its ability to stimulate binding. The DNA-enzyme complex partially dissociates on incubation in 0.1% sodium dodecyl sulfate and 0.5 M ammonium acetate. Some of this DNA could again form a tight complex with enzyme, indicating that DNA-enzyme complex formation is reversible. Binding occurs when the second cytosine in the sequence CCAGG is substituted by azacytosine. This is the cytosine that would normally be methylated by the enzyme. The binding is therefore due to specific interaction of the methylase with azacytosine at the site it would normally methylate.

Azacitidine↗
PubMed1986

Spontaneous postpartum regression of pituitary mass with return of function.

A 37-year-old woman undergoing endocrine evaluation during her seventh pregnancy because of headaches, weakness, and hyponatremia was found to have central hypoadrenalism and hypothyroidism. Computed tomography showed a pituitary mass with suprasellar extension but her visual fields were intact. She was treated conservatively with hydrocortisone acetate and levothyroxine sodium until 38 weeks of gestation, when healthy twins were delivered by cesarean section. A few months later, her pituitary function improved, with a significant increase in the adrenocorticotropic hormone level, normal values of basal thyroid-stimulating hormone, growth hormone, and gonadotropins and of their functional reserves, and only a slight elevation in the prolactin level. A repeated computed tomographic scan showed disappearance of the pituitary mass.

Adult↗
PubMed1986

Effects of red blood cell potassium and hypertonicity on the growth of Plasmodium falciparum in culture.

Malarial parasites reproduce asexually inside the erythrocytes of their vertebrate host. Relatively little is known about the interaction between host cell and parasite metabolism. In the present study the effect of host cell cation composition and osmotic shrinkage on in vitro growth and propagation of Plasmodium falciparum in human erythrocytes was investigated. It is shown that throughout the parasite cell cycle, infected cells lose potassium and gain sodium. Compartment analysis of infected cells revealed that host cell cytosol is poor in potassium and rich in sodium while in the parasite this relationship is reversed, indicating that the parasite is able to regulate its ionic composition independently. Parasites proceeded normally through their cell cycle in the presence of the sodium-pump inhibitor ouabain, although host cells lost up to 75-80% of their normal potassium content. Potassium-depleted erythrocytes harboring trophozoites and schizonts also display normal rates of protein synthesis as measured by isoleucine incorporation. Parasite growth was inhibited when infected cells were osmotically shrunken in hypertonic media, but this was not due to parasite dehydration. It is suggested that increased viscosity of host cell cytosol and/or hemoglobin gelation, are responsible for the effect, probably through interference with parasite feeding. The relevance of these results to understanding of the cellular mechanism involved in the inhibiton of parasite growth in deoxygenated sickle-trait erythrocytes is discussed.

Erythrocytes↗
PubMed1986

Treatment of hypertension during pregnancy with hydralazine monotherapy or with combined therapy with hydralazine and pindolol.

Forty-four consecutive patients referred for treatment because of hypertension (greater than 150/90 mmHg) occurring during pregnancy were randomly allocated to one of two treatment groups, hydralazine alone (n = 21) or hydralazine combined with pindolol (n = 23). Satisfactory blood pressure control (diastolic pressure less than 90 mmHg) was achieved in 86% of patients receiving hydralazine alone and 91% of those on combined therapy. Although the treatment did not lower the overall incidence of hypertensive complications it appeared to delay the onset of such complications until successful surgical intervention was possible. Fetal outcome was similar in both groups and there was no perinatal mortality in this high-risk population. Although blood pressure control was similar in both groups of patients, combined therapy with hydralazine and pindolol can be considered to be superior to hydralazine monotherapy, since in patients treated with the combination the incidence and intensity of troublesome side-effects was markedly lower.

Adult↗
PubMed1986

Long-term culture of infant leukemia cells: dependence upon stromal cells from the bone marrow and bilineage differentiation.

Infant leukemia cells with 46XY,t(11; 17)(q23; p13) karyotype and a hybrid pre B myeloid phenotype (HLA-DR, (Ia), B4 and My7-positive and CALLA and T11-negative) and immunoglobulin heavy chain gene rearrangement were maintained in long-term culture for over 10 months. The in-vitro survival and growth of the leukemia cells were strictly dependent upon the presence of their autologous marrow stromal cells. The latter could be replaced by the 14F1.1 clone of preadipocytes derived from mouse bone marrow. Neither heterologous human marrow or foreskin fibroblasts nor fibroblast or endothelial like cell lines from mouse stroma could mimic the effect of autologous stroma or 14F1.1 adipocytes. The leukemia cells maintained their original phenotype throughout the 10-month culture period with either their autologous stroma or the 14F1.1 adipocytes. They could be induced to differentiate in two distinct directions. Phorbol myristate acetate induced adherence of the leukemia cells and development of macrophage properties. In contrast, conditioned medium from a hybridoma producing B-cell growth factor caused aggregation of the leukemia cells and expression of CALLA antigen and surface IgM. This bipotency of the leukemia cells and their dependence upon marrow stroma are properties in common with stem cells.

Bone Marrow Cells↗
PubMed1986

The regulation of blood sugar in the aging blowfly, Phormia regina.

The adult blowfly, Phormia regina, reveals a substantial homeostatic capability when examined for its ability to regulate externally administered additions to its blood sugar. As well, results of experiments done at intervals throughout the entire adult life of the fly show that there is no decrease over time in the efficiency of operation of the complex system involved in the control of the blood sugar level. Taken together with other independent investigations of Phormia metabolism, the research indicates that this animal, in contrast to the rat, possesses a number of physiological systems which embody regulatory processes that may be only marginally subject to the normal "aging" process.

Aging↗
PubMed1986

Clinical results of terminal salpingostomy with the use of the CO2 laser: report of the Intraabdominal Laser Study Group.

Forty-eight women underwent terminal salpingostomies with a standard operative procedure with the use of the CO2 laser and microsurgical techniques at five centers. Early second-look laparoscopy was performed in all patients 1 to 12 weeks after the laparotomy. The tubal patency rate at the second look was 92% for these 48 patients, with a minimum of 6 months' follow-up study in all patients. Of these patients, ten became pregnant (21%), one with an ectopic pregnancy (10%). All pregnancies occurred within 12 months of the second-look procedure. It is preliminarily concluded from this series that use of the CO2 laser for neosalpingostomy at laparotomy with early second-look laparoscopy provides a term pregnancy rate similar to that previously achieved by nonlaser microsurgical techniques and shortens the time period between the surgical procedure and when conception would be expected to occur.

Adult↗
PubMed1986

Severe regressive reactions in sex therapy.

In this paper we describe five cases of severe regressive reaction during the initial evaluation of treatment for sex therapy. We focus on three dimensions useful for assessment in guarding against such regressions: the nature of the patient's defensive posture; the nature of the couple's interaction and dynamics regarding the sexual symptom; the context of the referral for brief sex therapy treatment. The particular constellation of these factors appear to make regressive reactions quite likely. Guidelines for evaluation and handling decompensation are briefly noted.

Adult↗
PubMed1986

Adverse reactions to antihypertensive drugs in pregnancy.

In conclusion from a clinical pharmacological point of view it is stressed that side effects from antihypertensive therapy in part is related to dosage. Increased knowledge should make it possible to reduce the rate of side effects. In the individual case the physician always has to compare a number of factors: general condition of the patient, age, adherence to the prescribed therapy, side effects, and other factors in addition to blood pressure values. With all these limitations in mind there is agreement that the benefit of antihypertensive therapy far out-weigh the negative aspects of such treatment.

Antihypertensive Agents↗
PubMed1986

Partition functions of unit-copy plasmids can stabilize the maintenance of plasmid pBR322 at low copy number.

The maintenance of plasmid pBR322 is highly unstable in a polA12 strain of Escherichia coli at 29 degrees C due to severely reduced copy number. Under these conditions, introduction of the par (partition) locus of plasmid P1 or the par (sop) region of F into pBR322 stabilizes it. A region with similar activity was detected in the P7 plasmid. The activity of the P1 par locus was dependent on the P1 parA gene product and was sensitive to par-specified incompatibility.

DNA Replication↗