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Biomedical subjects

M Joffe

Publications and source records attributed to M Joffe.

At least 91 records · Page 5Linked to original sources
PubMed1988

Advantages of a standard method for research on reproductive effects of occupation.

A recent review of the literature identified several common methodological weaknesses in studies of the effects of occupational exposures on male and female reproductive processes. This paper suggests a strategy which addresses these problems, by the use of a standard method. The potential benefits include increased measurement reliability and statistical power, together with a systematic study of expected (background) rates, confounding effects, types of exposure and selection effects. Particular advantages are the avoidance of designating a group as non-exposed with attendant problems of bias, and in the longer term the study of multiple or rare exposures.

Environmental Exposure↗
PubMed1988

Stairway injuries in children.

Children frequently injure themselves falling down stairways, but the characteristics of these injuries are not well described. A total of 363 consecutive patients seen in a pediatric emergency department were studied. The majority of patients had minor superficial injuries. Bony injuries occurred in 7% of patients. Head and neck injuries occurred in 73% of patients, extremity injuries, which were predominantly distal, in 28%, and truncal injuries in 2%. Children younger than 4 years of age were more likely to sustain head trauma than children older than 4 years of age (P less than .005). Injury to more than one body part occurred in only 2.7% of patients. Children who fell down more than four steps had no greater number or severity of injury than those who fell down less than four steps (P = .67). Patients were admitted to hospitals in 3% of cases. No patient had life-threatening injuries and no patients required intensive care. When multiple, severe, truncal, or proximal extremity injuries are noted in a patient who reportedly fell down stairs, a different mechanism of injury should be suspected.

Accidental Falls↗
PubMed1987

Idiopathic haemochromatosis. Family studies and results of a pilot prevalence survey.

HLA typing for the A and B loci was carried out in conjunction with measurements of iron status on 38 of the first-degree relatives of 8 patients suffering from idiopathic haemochromatosis (IHC). Seven of the 8 probands had the A3 allele, 2 in the homozygous form. Seven had the B7 allele and in 5 it was present with the A3 allele on the same chromosome. Six family members were diagnosed as homozygous for the HLA-linked iron-loading gene on the basis of genotype assessment, while 27 were assessed as being heterozygous. Five of the 6 homozygous subjects had developed significant iron overload. In contrast, disturbances of iron metabolism in the heterozygotes were mild and present in only 33%. Pseudodominant inheritance of IHC was noted in one family, presumably as the result of a homozygous/heterozygous mating. A pilot epidemiological survey was carried out on 222 Afrikaans-speaking men in an attempt to find affected individuals using the serum ferritin concentration as the screening test. One homozygous subject was identified (genotype A3, B7/A3, B7) and further family studies confirmed the presence of the HLA-linked iron-loading gene. These preliminary results suggest a disease frequency of about 4-5/1,000 in the Afrikaner population.

Adolescent↗
PubMed1985

Biases in research on reproduction and women's work.

In the investigation of the possible reproductive effects of women's work, it is necessary to take into account the various biases which may occur as a result of the complex interaction between a woman's child-care responsibilities, work status, income and other aspects of her life. This paper distinguishes four effects and suggests methods of avoiding the resulting biases. Research in this area requires special care in design and analysis.

Adult↗
PubMed1984

Association of syndromes predisposing to low birthweight.

In a geographically-defined sample of low birthweight deliveries, the incidence was measured of ante-partum haemorrhage, hypertension, placental insufficiency and premature rupture of the membranes. When more than one of these syndromes was present, a clear pattern of segregation into pairs was noted, ante-partum haemorrhage tending to occur with premature rupture of the membranes, and hypertension with placental insufficiency.

Female↗
PubMed1983

Eosinophilia in premature neonates. Phase 2 of a biphasic granulopoietic response.

Eosinophilia within the first 6 weeks of life was studied prospectively in 10 premature neonates. Mean birthweight was 1229 +/- 314 g, and mean gestational age 31.5 +/- 1.8 weeks. Simultaneous changes in eosinophil, neutrophil, total lymphocyte, suppressor and helper T-cell counts and IgE levels were monitored. Infants were designated as responders (eosinophils greater than 1000/microliter for greater than 5 days) and non-responders. In the 6 responders eosinophils increased from 353 +/- 76 (mean +/- SEM) at birth to a peak of 2783 +/- 430/microliter at 20-25 days. Responders had significantly lower neutrophil counts at birth (P less than 0.05), and in 5 of the 6 responders neutrophils increased by more than 100% within 10-15 days; this did not occur in any of the 4 non-responders (P less than 0.025). Lymphocytes and suppressor and helper T cells increased progressively in both groups over the period of study with no differences between responders and non-responders. Birthweight and gestational age were similar in both groups, and there were no apparent causes for the lower neutrophil counts in responders at birth. Eosinophilia was not related to an IgE response. The incidence of eosinophilia in this study is similar to that reported previously, and appears to be part of a biphasic granulopoietic response.

Eosinophilia↗
PubMed1983

Respiratory activities of subsarcolemmal and intermyofibrillar mitochondrial populations isolated from denervated and control rat soleus muscles.

Ultraturrax and Nagarse released populations of mitochondria isolated from control and day 21 denervated rat soleus muscle were characterized with respect to their oxidative phosphorylation, ADP translocase and ATPase activities. Both Ultraturrax and Nagarse released mitochondrial populations displayed lower capacities for oxidative phosphorylation; lower ADP translocase activities and higher Mg2+ stimulated ATPase activities than their corresponding controls. For both the denervated and control states, the Nagarse-released mitochondrial populations displayed significantly higher respiratory activities than the Ultraturrax released fractions. The significance of these findings is discussed with regard to the process of mitochondrial respiratory control. In addition the role of mitochondrial dysfunction in denervation muscular atrophy is assessed.

Adenosine Triphosphatases↗
PubMed1983

The enhancement of eosinophil function by lymphocyte supernatants.

Supernatants obtained from non-stimulated lymphocytes, lymphocytes stimulated with phytohaemagglutinin and lymphocytes from patients with schistosomiasis that were stimulated with Schistosomiasis haematobium ova were shown to enhance a number of eosinophil functions. Eosinophil chemotaxis, phagocytosis, microbicidal activity, Nitro blue tetrazolium reduction, hexose monophosphate shunt activity and glycolysis were increased. Eosinophil iodination was not affected. Only those supernatants obtained from phytohaemagglutinin stimulated lymphocytes and lymphocytes from patients with schistosomiasis that were stimulated with S. haematobium ova showed eosinophil chemotactic activity. The active factor was found to be heat stable, and had no effect on cAMP and cGMP metabolism. The most likely mechanism of enhanced eosinophil function is through the increased activity of the hexose monophosphate shunt activity and glycolysis.

Blood Bactericidal Activity↗
PubMed1981

Ca2+-uptake properties of two populations of mitochondria from normal and denervated rat soleus muscle.

Ultraturrax- and Nagarse-released populations of mitochondria were characterized with respect to their Ca2+-uptake activities (i) by means of the indirect polarographic technique and (ii) directly by the 45Ca Ruthenium Red-quench method of Reed & Bygrave [(1974) Biochem. J. 140, 143-155]. The denervated-muscle subsarcolemmal and intermyofibrillar mitochondrial fractions displayed markedly decreased rates and capacities for Ca2+ uptake compared with their respective controls. The implications of these findings with respect to the process of cell necrosis are discussed.

Animals↗
PubMed1981

Increased muscle calcium. A possible cause of mitochondrial dysfunction and cellular necrosis in denervated rat skeletal muscle.

Mitochondrial preparations derived from denervated rat skeletal muscle and paired controls were characterized with respect to their ability to take up externally added Ca2+. The denervated and control muscle homogenates and mitochondrial [Ca2+] were also determined. Our data indicate that the denervated mitochondria are able to take up less Ca2+ than the controls before uncoupling occurs. This defect is associated with elevated [Ca2+] in homogenate and mitochondrial fractions in the denervated state. The causal relationship between Ca2+ overload, mitochondrial functional damage and cell necrosis is discussed.

Animals↗
PubMed1981

Urine protease and antiprotease activity in experimental aminonucleoside nephrotoxicity.

Induction of nephrosis in rats with aminonucleoside of puromycin (ANP) was followed by an increase in urinary protease activity, measured by the cleavage of 14C-globin, as well as in antiprotease activity measured by trypsin inhibition. The excretion of protease and protease inhibitor coincided with but did precede the onset of proteinuria when the ANP was injected subcutaneously for 5 days and lagged after proteinuria when the ANP was given as a single intravenous dose. Serum protease activity did not change throughout ANP treatment or later, whereas serum antiprotease capacity declined coincidently with proteinuria, most probably due to the loss in urine. Kidney proteolytic activity was markedly reduced in ANP nephrosis. Treatment of rats with proteolysis inhibitors, trasylol, episilon-aminocaproic acid, soybean trypsin inhibitor, or hexapron, together with ANP failed to prevent, delay or reduce the proteinuria. We believe that the urinary protease in ANP nephrosis does not originate from the circulation but from the release of kidney protease as a consequence of the glomerular lesion, and does not appear to be involved in its causation.

Animals↗
PubMed1981

The in vivo and in vitro effects of levamisole in patients with lepromatous leprosy.

Levamisole, 150 mg daily, was administered on 2 consecutive days per week for 6 weeks to two groups of patients with lepromatous leprosy. Group I was composed of patients who were receiving specific anti-leprosy therapy for varying periods of time and Group II were untreated lepromatous patients. Whereas half the patients in Group I received levamisole and the other half a placebo, those in Group II all received levamisole. Patients in both groups showed a) no clinical improvement, b) no conversion of the lepromin reaction, c) no histological change in skin biopsies, d) conversion of SKSD skin reactions from negative to positive in 20% of patients from each group, and e) unaltered absolute neutrophil counts. Whereas the total lymphocyte counts were unchanged in patients from Group I, 13 patients from Group II showed an increased lymphocyte count of greater than 10%. Lymphocyte transformation and lymphokine production in the second group showed no significant change, although four patients showed some lymphokine production after levamisole therapy. E and EAC rosettes were significantly increased in cases where these were reduced prior to treatment with levamisole-Side effects due to levamisole were not experienced.

Adolescent↗
PubMed1975

Leucocyte function in children with kwashiorkor.

A study of leucocyte response to infection, polymorphonuclear leucocyte chemotaxis and bactericidal activity, and nitroblue tetrazolium (NBT) reduction in children with kwashiorkor was undertaken and compared with a control group. The results show that total leucocyte counts were depressed in children with kwashiorkor, and lymphopenia was not infrequent. NBT reduction was normal. Abnormal polymorphonuclear leucocyte chemotaxis and bactericidal activity, though frequently found in children with kwashiorkor, was shown to be dependent on infection and not on protein depletion per se. Therefore, apart from some impairment of leucocyte mobilization in the presence of infection, the qualtiy of polymorphonuclear function, as determined by the above techniques, appears to be normal in kwashiorkor.

Blood Bactericidal Activity↗