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Biomedical subjects

M Katz

Publications and source records attributed to M Katz.

At least 235 records · Page 13Linked to original sources
PubMed1991

Traumatic atlanto-occipital dislocation in children: review and report of five cases.

Traumatic atlanto-occipital dislocation has usually been considered incompatible with life. However, reports on survivors stress the need for early clinical diagnosis of this condition, particularly in the context of multiple trauma, in order to avoid life-threatening diagnostic manipulations and to provide adequate treatment. Five instances of atlanto-occipital dislocation in children observed during the last two years prompted this report, since four of them survived only temporarily. The radiologic and computed tomographic (CT) findings have been reevaluated. Use of metrizamide CT is advised in clinically suspected cases with inconclusive radiologic workup.

Atlanto-Occipital Joint↗
PubMed1991

Effects of pravastatin and cholestyramine on gonadal and adrenal steroid production in familial hypercholesterolaemia.

1. Adrenal and gonadal steroids are derived from cholesterol, which may be derived from plasma lipoproteins or de novo synthesis. 2. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, the rate limiting enzyme in cholesterol synthesis, may therefore affect steroidogenesis when used as lipid-lowering agents in hypercholesterolaemia. 3. We have assessed gonadal and adrenal function in subjects with heterozygous familial hypercholesterolaemia (FH) before and after 12 weeks treatment with pravastatin, an HMG CoA reductase inhibitor, or cholestyramine as a control in maximal recommended doses. 4. No changes in measured plasma cortisol responses to tetracosactrin injection were seen in 11 patients on cholestyramine or 12 on pravastatin. 5. No changes were seen in testosterone, sex hormone binding globulin, androstenedione, dehydroepiandrosterone sulphate, oestradiol or 17 alpha-hydroxyprogesterone. 6. Gonadotrophin levels were unaffected in 10 male subjects on cholestyramine and 7 on pravastatin. 7. Measurements on a subset of subjects continuing to 24 weeks treatment also showed no changes. 8. No adverse effect on adrenal or gonadal function could be demonstrated in patients with familial hypercholesterolaemia on maximal recommended doses of pravastatin.

Adrenal Glands↗
PubMed1991

Subclavian vein stenosis, permanent cardiac pacemakers and the haemodialysed patient.

Two cases of subclavian vein stenosis secondary to permanent cardiac pacemakers are presented. Both stenoses were asymptomatic until arteriovenous fistulae/grafts were constructed in order to initiate haemodialysis. One patient experienced severe oedema of the arm which necessitated surgical closure of the graft. A literature review into major venous stenosis and cardiac pacemakers reveals an asymptomatic, but evidently underestimated, problem. As more elderly patients will be accepted onto haemodialysis programmes, this above-mentioned problem may become more common. Therapeutic answers as to haemodialysis access are discussed in these patients with permanent pacemakers who need haemodialysis.

Aged↗
PubMed1991

Oxidative stress in newborn erythrocytes.

Phenylhydrazine (PHZ) exposure is used to study in vitro red cell aging mechanisms dependent on Hb oxidation. The effect of PHZ on normal neonatal red blood cells was studied in unseparated blood and after separation into light and heavy cells. PHZ caused more extensive morphologic changes in neonatal than in adult red blood cells. PHZ exposure of neonatal cells caused less reduced glutathione depletion than in adult cells. Although we found the same total amount of oxidized Hb in both cells, a well-defined oxidation product of Hb was demonstrated by Mössbauer spectra only in neonatal cells. This oxidation product was not methemoglobin but a trivalent, high-spin iron compound. All neonatal cell populations were more sensitive to PHZ than were adult ones, as demonstrated by the presence of Heinz bodies at low PHZ concentration, which did not affect adult cells. These studies demonstrate greater sensitivity of neonatal cells to PHZ in all density-separated populations.

Adult↗
PubMed1991

Native valve bacterial endocarditis due to Staphylococcus epidermidis. A community acquired infection following an acute course.

Staphylococcus epidermidis (SE) is the leading pathogen of prosthetic valve endocarditis. At the same time it is a very rare cause of native valve endocarditis and it follows a clinical course and outcome similar to Streptococcal viridans endocarditis. We report here the case of a 41-year-old man with a community acquired SE endocarditis of a native aortic valve. Despite early surgical intervention, the case followed an acute and fatal course.

Adult↗
PubMed1991

[Pregnancy and labor in advanced renal failure due to chronic pyelonephritis].

The rare completion of a pregnancy in the presence of severe chronic renal failure is discussed in 6 cases. In all those cases the renal failure became worse, even though the pregnancy and delivery were satisfactory. Shortly after delivery, the 6 women underwent hemodialysis or peritoneal-dialysis. One patient died several weeks after delivery because of uremia. Our results suggest that for their own safety, women with severe renal failure should not become pregnant.

Adult↗
PubMed1991

Triplet pregnancy: changes in morbidity and mortality.

The outcome of 13 sets of triplet infants delivered between January 1, 1981, and December 31, 1988, is analyzed with specific regard to immediate neonatal morbidity. Thirty-nine viable infants were born with no perinatal deaths. Overall, 80% of triplet infants incurred some morbidity, including hyperbilirubinemia (51.3%), hypoglycemia (30.8%), respiratory distress syndrome (28.2%), respiratory compromise (23.1%), anemia (17.9%), patent ductus arteriosus (15.4%), and intraventricular hemorrhage (10.3%). All morbidities occurred in infants who averaged less than 2,000 g and 35 weeks' gestation at birth. As a background to understanding these observations, a review of reports of triplet morbidity and mortality in the United States and Europe is presented. Over the past 80 years, a continual decline in triplet perinatal mortality has occurred despite no change in the average gestational age at delivery over the past 40 years. The triplet perinatal mortality rate is now less than 10%, and prematurity is no longer as influential on perinatal mortality as it is on morbidity. Improvement in neonatal resuscitation and care and delivery by cesarean section are felt to be responsible for lower mortality rates. We believe that the optimum level of care for triplet gestations includes antenatal and neonatal care at tertiary perinatal centers and, except for special circumstances, delivery by cesarean section.

Adult↗
PubMed1991

Pregnancy and delivery in a patient with Uhl anomaly.

We followed throughout pregnancy and delivery a 26-year-old woman suffering from a severe form of Uhl anomaly (congenital arrhythmogenic right ventricular dysplasia with severe enlargement and hypokinesis of the right ventricle, tricuspid valve insufficiency, and mild pulmonary valve insufficiency). Despite severely impaired cardiac function, the patient tolerated pregnancy surprisingly well. At 37.4 weeks' gestation, prophylactic low-dose heparin was started. Three days later she delivered a healthy 2700-g girl by elective cesarean performed under intensive cardiac surveillance.

Adult↗
PubMed1991

Cryptosporidium in Bedouin and Jewish infants and children in southern Israel.

We conducted a 1-year prospective study in two clinics and a hospital in the Negev region of southern Israel to determine the epidemiological and clinical patterns of Cryptosporidium diarrhea among Jewish and Bedouin infants and children living in the same geographical area. A total of 612 episodes were studied: 398 in Bedouins and 214 in Jews, of which 449 occurred in patients with diarrhea and 164 in controls. Cryptosporidium was detected in 13 of 382 patients (3.4%) with diarrhea and in 1 of 138 controls (0.7%) (P = 0.078). In 5 of 13 Cryptosporidium-positive patients (38%) another pathogen was detected. No significant difference in Cryptosporidium detection rates was observed between Jews and Bedouins or between hospitalized or nonhospitalized patients. The frequency of Cryptosporidium detection did not differ significantly when three age-groups were compared (less than 6 months old, 7-12 and 13-36 months old). The rate of Cryptosporidium detection was similar among malnourished and well-nourished patients, as determined by weight-for-height percentiles. Cryptosporidium was detected more frequently during the summer months (8.3%) than during the rest of the year (1.2%) (P less than 0.001). Patients with Cryptosporidium diarrhea did not differ clinically from patients with other causes of diarrhea. However, they were characterized by the absence of fecal leukocytes. Cryptosporidium is not a rare cause of diarrhea in southern Israel. It is more prevalent during the hot and dry season and can be detected in a relatively high prevalence among very young infants. Its clinical features are indistinguishable from those of patients with non-cryptosporidial diarrhea.

Child, Preschool↗
PubMed1990

[Discrepancy in histopathological findings of curettage material and hysterectomy specimens in malignant tumors of the uterine body].

The clinical staging of the malignoma of the uterine corpus according to the FIGO classification corresponds in only 85.7% in stage I and 35.7% in stage II to the histopathologic staging after operation. Tumor grading and histology from D and C differ in 31.8% and 9.4% respectively from the hysterectomy specimen. We propose therefore to prefer surgical and histopathological staging to the pure clinical FIGO-staging in order to plan adjuvant therapy and for comparing therapeutic results of different patient groups as well.

Adenocarcinoma↗
PubMed1990

Familial congenital diaphragmatic defect and associated midline anomalies: further evidence for an X-linked midline gene?

We report on familial occurrence of congenital diaphragmatic defect and associated midline anomalies, namely cleft palate and omphalocele in brothers. This family further supports the existence of an X-linked gene involved in the organization of the embryonal midline. This particular mutant gene might be active in the schisis-morphogenesis phenomena occurring at the midline.

Cleft Palate↗
PubMed1990

Phototoxic liposomes coupled to an antibody that alone cannot modulate its cell-surface antigen kill selected target cells.

Molecules such as antibodies that bind to cell surfaces can be used to deliver cytotoxic drugs to selected cells. To be effective the drug must usually be taken into the cells by endocytosis. In this study a T-cell line (CCRF-CEM) was effectively killed by liposomes carrying a photosensitizer and bearing the antibody OKT4 (anti-CD4). The unconjugated antibody does not induce antigenic modulation in the target cells, an indication of the absence of endocytosis, and would therefore not normally have been selected as an agent for drug delivery. It cannot, however, be concluded with certainty that the conjugates act at the cell surface and several alternative explanations of their efficacy are offered.

Animals↗
PubMed1990

Effect of 1,25-dihydroxyvitamin D3 on human keratinocytes grown under different culture conditions.

1,25-Dihydroxyvitamin D3 (1,25-(OH)2-D3) is known to decrease the proliferation and increase the differentiation of different cell types including human keratinocytes. The growth and differentiation of keratinocytes in the presence of 1,25-(OH)2-D3 using serum-free media formulations has been described previously. This investigation extends these studies to describe various culture conditions with human foreskin keratinocytes to determine the optimal antiproliferative activity of 1,25-(OH)2-D3. Keratinocytes were plated onto tissue culture dishes using one of three basic serum-free media protocols; a) with no feeder layer in keratinocyte growth medium (KGM); b) onto mitomycin C-treated 3T3 mouse embryo fibroblasts; or c) onto mitomycin C-treated dermal human fibroblasts. The last two protocols utilized Dulbecco's modified Eagle's Medium (DMEM) supplemented with growth factors. Keratinocyte cell growth was greatest in the KGM medium. Although the growth of keratinocytes on either feeder layer was similar, there were differences in the ability of the cells to form envelopes in the presence of 1,25-(OH)2-D3. The addition of hydrocortisone and cholera toxin to the medium also affected the response of the keratinocytes to 1,25-(OH)2-D3. The antiproliferative effect of 1,25-(OH)2-D3 was not altered by varying the extracellular calcium levels from 0.25 to 3 mM. The antiproliferative activity of 1,25-(OH)2-D3 is attenuated in cells at low density. Our results suggest that an optimal condition to investigate the ability of 1,25-(OH)2-D3 to inhibit keratinocyte proliferation is at preconfluent cell density in the presence of KGM supplemented with 1.5 mM calcium without a feeder layer. These conditions are not appropriate for investigating the enhancement of differentiation by 1,25-(OH)2-D3, but can be used to assay other agents that modulate keratinocyte proliferation.

Calcitriol↗
PubMed1990

Early signs and symptoms of preterm labor.

Patient and staff education concerning the subtle signs and symptoms that precede a clinical diagnosis of preterm labor have not been well established. Therefore we interviewed 100 patients for the presence or absence of various symptoms and signs during the 7 days preceding diagnosis of preterm labor. An additional 100 patients without preterm labor matched for gestation were chosen at random as control subjects. A history of increased uterine contractions, menstrual cramps, constant backache, constant pelvic pressure, increased amount and consistency and color change of vaginal discharge, and increased frequency of urination were present with a statistically significant higher frequency in patients with preterm labor compared with controls. Twenty-nine percent of patients did not report any uterine contractions and only half described them as painful. Fewer than 50% of the women reported contractions as frequently as every 10 minutes or more.

Adult↗
PubMed1990

Rotavirus diarrhea in Jewish and Bedouin children in the Negev region of Israel: epidemiology, clinical aspects and possible role of malnutrition in severity of illness.

We conducted a 1-year prospective study in the Negev region of southern Israel to determine the epidemiologic and clinical patterns of rotavirus diarrhea. A total of 605 patients were studied, 392 Bedouins and 213 Jews, 441 of whom had diarrhea (449 episodes) and 164 did not. Rotavirus was the most common organism detected in children with diarrhea (63 of 444; 14%) but was rarely found in controls (3 of 163; 2%) (P less than 0.001). In 22% (12 of 54) of the rotavirus-positive patients, at least one other organism was also detected. The rate of rotavirus detection decreased as age increased, from 18% in the first year to 8% in the third year of life. Hospitalization with rotavirus diarrhea occurred more frequently in the summer. However, during winter, when diarrhea was less prevalent in the community, the proportion of cases associated with rotavirus was higher. Compared with controls, malnourished children were more likely to be hospitalized. However, rotavirus was detected in similar proportions among well-nourished and malnourished cases with diarrhea. The most prevalent rotavirus serotype was type 1 (in 69%), followed by types 4 and 2 (18 and 13%, respectively). We estimated that during the study period, approximately 2% of all Bedouin infants vs. only 0.2% of Jewish infants were hospitalized with rotavirus disease in their first year of life. Clinical signs and symptoms and stool appearance were not useful in predicting rotavirus detection. Malnutrition seems to be an important indicator of disease severity, which may explain why the toll of rotavirus-associated morbidity and mortality is particularly high among children in developing countries.

Acute Disease↗