Search PubMed⌕ Search

Biomedical subjects

S Isaacs

Publications and source records attributed to S Isaacs.

At least 55 records · Page 3Linked to original sources
PubMed1992

PEG-400 excretion in patients with Crohn's disease, their first-degree relatives, and healthy volunteers.

An altered small bowel permeability may be implicated in the pathogenesis of Crohn's disease. Intestinal permeability, using polyethylene glycol 400 (PEG 400) as the orally ingested probe, was assessed in 45 patients with Crohn's disease (ileal N = 14, ileocolonic N = 9, colonic N = 10, postresection N = 12), 20 first-degree relatives, and 31 controls. PEG 400 excretion was measured using a direct injection HPLC method, and results are expressed as percent of dose recovered in urine (median and range). No quantitative differences in the recovery of PEG-400 were found [Crohn's patients 21.9% (6.1-39.9), relatives 23.7% (4.9-39.9), controls 25.0% (4.5-39.7)]. In all groups, the composition of ingested and recovered PEG-400 was similar and no selective permeability to any molecular weight species was found. Disease site did not influence probe recovery [ileal 23.8% (7.7-30.6), ileocolonic 22.6% (14.4-33.8), colonic 27.8% (9.5-33.5)]. Resected patients had significantly lower PEG-400 recovery [18.8% (8.1-39.9)] than nonresected patients [23.5% (6.1-33.8%) P less than 0.02]. The data suggest either that altered intestinal permeability is not a factor in Crohn's disease or that PEG-400 is not a suitable probe.

Cell Membrane Permeability↗
PubMed1992

Prospective, randomized study comparing amoxycillin-clavulanic acid and cefamandole for the prevention of wound infection in high-risk patients undergoing elective biliary surgery.

The efficacy of amoxycillin-clavulanic acid for prevention of postoperative wound infection was compared with that of cefamandole in 150 patients at risk for infected bile while undergoing elective biliary surgery in a prospective, randomized study. The two groups were comparable for age, sex, risk factors, operative procedures and positive bile cultures. Similar numbers of patients had an uncomplicated postoperative course (amoxycillin-clavulanic acid 70%; cefamandole 73%). Four patients in each group developed wound infection. The incidence of postoperative pneumonia, urinary tract infection and number of days (+/- SD) in hospital (amoxycillin-clavulanic acid 10.1 +/- 4.7; cefamandole 9.7 +/- 5.6) were similar. The efficacy of amoxycillin-clavulanic acid and cefamandole in preventing wound sepsis in high-risk patients undergoing biliary surgery was similar. Economic considerations may favour the use of amoxycillin-clavulanic acid.

Adolescent↗
PubMed1992

A descriptive study of the attachment of public health nurses to family physicians' offices.

Public health nurses (PHNs) have been attached to family doctors' offices as one mode of organizing the delivery of nursing services in the community. However, different nurses function in different roles on a continuum from generalist to liaison. A descriptive study was undertaken to determine the most effective role for PHNs attached to family physicians' offices. Outcomes for both physicians and nurses were satisfaction with the role of the PHN, appropriateness of referrals, and accessibility for consultation. These outcomes were compared relative to the rating of PHNs of their role. A cohort of physicians without attachment PHNs were also surveyed to compare responses on the same criteria. The majority of nurses described their role generalist. This role was related to greater satisfaction for nurses and the physicians with whom they worked. Satisfaction with PHN service, ease of arranging consultation with PHN, and appropriateness of referrals from PHNs was greater for physicians who had the attachment than those who used the usual service.

Family Practice↗
PubMed1991

Delay in the diagnosis of cutaneous malignant melanoma. A prospective study in 250 patients.

The extent and consequence of patient and professional delay in the diagnosis and treatment of 250 consecutive patients with primary cutaneous malignant melanoma was investigated. Mean total delay from the onset of observed change in a melanoma to appropriate therapy was 11.1 months. The major component of delay (9.8 months) was patient related. Seventy-nine (31.6%) patients waited more than 6 months before seeking medical attention. Few patients recognized early melanoma, and 46% responded only to late features (i.e., ulceration or bleeding). Inappropriate professional delay (misdiagnosis or observation without specific action) occurred in 30 consultations (12.4%) and resulted in a further 1.3-month mean delay in treatment. No correlation (r = 0.027) was found between delay in diagnosis and thickness of melanoma for the study population overall. A significant relationship (r = 0.2087; P less than 0.05) was found between longer lag time and advanced disease in 92 patients with nodular melanoma. Asymptomatic melanomas incidentally diagnosed during routine skin surveillance were significantly more favorable (mean depth, 0.89 mm) than symptomatic melanoma (1.76 mm; P less than 0.01). These data suggest that future public education campaigns should emphasize early signs of melanoma and that professional programs should stress routine skin surveillance and prompt referral of suspicious lesions for diagnostic biopsy.

Adolescent↗
PubMed1991

Zona incerta lesions: effects on copulation, partner-preference and other socio-sexual behaviors.

Sexually active males prefer a sexually receptive female to a non-receptive female, and partner-preference tests provide one way of studying the effect of brain damage on sexual motivation. Male rats with bilateral electrolytic lesions of the caudal zona incerta do not mate, and we studied the effects of zona incerta destruction on copulation and partner-preference. Lesioned males did not mate but were not indifferent to sexually receptive females. They continued to show a strong preference for a sexually receptive female over a non-receptive female. In addition, lesioned males showed many incomplete mounts i.e. mounts not accompanied by the pelvic thrusting necessary for intromission and ejaculation. Anogenital investigation of the receptive female was common. Taken together, these facts suggest that zona incerta destruction eliminates copulation without affecting sexual motivation, and that the failure to mate after lesioning probably reflects an inability to properly engage the locomotor responses of copulation.

Animals↗
PubMed1990

Standardisation of perinatal mortality rates.

Birth weights and perinatal deaths for the Peninsula Maternal and Neonatal Service were analysed for 1974-1987. There were differences in birth-weight distribution between the ethnic groups, and within the white group, over time, and these influenced the crude perinatal mortality rates. Once birth weight had been adjusted for, there was a downward trend in the data for all groups. The improvement in the perinatal mortality rates was related to better survival in each group. There was no difference in the standardisation rates between the coloured and white infants. Blacks, however, had significantly higher rates when compared with the coloured and white births.

Birth Weight↗
PubMed1990

Disturbed oesophageal motility after eradication of varices by chronic sclerotherapy--a scintigraphic study.

Oesophageal function after sclerotherapy for varices in 29 patients was compared with that in 15 patients with untreated varices using a scintigraphic technique. The first group had significantly longer transit times in each third and also in total time compared with a control group of 32 subjects (upper-third P = 0,02; middle-third P = 0,01; lower-third P = 0,0001; and total transit time P = 0,0001). Minor abnormalities of transit were found when the untreated group was compared with controls (increased total transit time P = 0,02). These results indicate that abnormalities of transit are increased after sclerotherapy for varices.

Adult↗
PubMed1990

Relative efficacy of nebulised ipratropium bromide and fenoterol in acute severe asthma.

In a double-blind, randomised, controlled clinical trial of 145 patients with acute asthma, the efficacy of nebulised 4-hourly ipratropium bromide plus 4-hourly fenoterol (group I, 50 patients), 2-hourly fenoterol (group II, 50 patients) and 4-hourly fenoterol (group III, 45 patients) was assessed. All patients received an optimal infusion of aminophylline and 81 patients (27 in each group) received hydrocortisone for clinical indications. It was found that cholinergic side-effects in group I were not more common than in group II. Tremor was more common in group II. Assessment of bronchodilator efficacy was confined to the 81 patients whose therapy included hydrocortisone. Peak expiratory flow rate, forced expiratory volume in 1 second, and forced vital capacity were expressed as a percentage of predicted for each individual and the mean values for each group plotted. It was found that the response rate, as assessed by the area under the curve, was significantly more rapid in group I compared with both group II (P less than 0.001) and group III (P less than 0.005). These findings were consistent for all three lung function measurements. However, there was no significant difference in the responses between group II and group III. It is concluded that adding ipratropium bromide to conventional regimens is likely to benefit patients with acute asthma.

Acute Disease↗
PubMed1989

Current trends in infant feeding.

This study examined aspects of newborn feeding in a maternity hospital and also investigated feeding practices during the first 6 months of life. Four hundred and fifty mothers were interviewed while in the maternity hospital. The majority (93%) had booked for their confinement and had attended antenatal clinics regularly. Most had had early contact with the baby at birth and stated that they thought breast-milk was best for the baby. Despite this only 54.6% had given breast-milk as the first feed and only 10% had done so within the first hour. Most mothers (54%) stated that they preferred a timed feeding routine to demand-feeding, while 86% planned to give water between feeds. The majority indicated they would change to formula feeds should they experience problems with breast-feeding. A follow-up visit of 78 mothers 6 months later showed that 50% breast-fed exclusively for 3 - 4 months and 23% for 6 - 7 months. When feeding problems occurred only 27% of the mothers utilised the local authority baby clinic for help. The main reasons given for stopping breast-feeds were insufficient milk, the need for employment and feeding problems. The implications of these findings are discussed.

Attitude↗
PubMed1989

Promoting family planning for better health: policy and programme implications.

Renewed emphasis is being given to the role of family planning health care programs. This review of the lessons learned during the past decade provides guidance to policy makers and program managers on ways to improve maternal, infant, and child health through family planning and related health and development activities. It covers policies and laws, accessibility to services, acceptability and quality of services, provision for the special needs of high-risk groups, the use of communications programs, the importance of improving the status of women and the quality of life, and the resources needed to implement such a program globally. Practical steps for integrating family planning fully into maternal and child health care are described.

Birth Intervals↗
PubMed1988

The effects of denervation and acute rejection on left ventricular volumes measured by radionuclide ventriculography following cardiac transplantation in the chacma baboon.

Seven baboons underwent autotransplantation of the heart or heart and both lungs (group A). Eleven allografts were performed (group B) (nine orthotopic heart transplants and two en bloc transplants of the heart and both lungs). Radionuclide ventriculography was performed both pretransplant and at intervals posttransplant in all animals, and provided measurements of ejection fraction (EF) and left ventricular volumes (LVv) (end-diastolic volume [EDV], end-systolic volume [ESV], and stroke volume [SV]). In seven animals, a total of 20 endomyocardial biopsies were taken. Correlation was made between histopathological features of acute rejection seen on endomyocardial biopsy and changes in EF and LVv measured by radionuclide imaging. A significant increase of 12% in the EF (P less than 0.01) and significant falls in the LVv were observed in all animals (groups A and B) on the first posttransplant day, presumably a result of total cardiac denervation. EDV was reduced by 50% (P less than 0.005), ESV by 62% (P less than 0.0001), and SV by 43% (P less than 0.0001). In autografted baboons (group A) EF and LVv showed no further changes until reinnervation of the heart had occurred, when they reverted to pretransplant levels. In the allografted baboons (group B) further significant reductions in the LVv occurred as acute cardiac rejection progressed. From the first post-transplant day to the time of the final study before the animals' death, the EF decreased by 10% (P less than 0.01), the EDV by 38% (P less than 0.005), and SV by 73% (P less than 0.003): the decrease in ESV did not reach statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1988

The role of nuclear cardiology procedures in the evaluation of cardiac function following heart transplantation.

Heart transplantation is, today, an accepted and recommended modality in the management of selected patients suffering from terminal heart disease. However, acute rejection and infection remain the major complications of this operation. Serial endomyocardial biopsy (EB), considered as the standard for diagnosis of cardiac rejection, is an invasive and delicate operation, not free of complications, even when done by skilled personnel in specialized centers. The object of this study was to compare and correlate between radionuclide ventriculography (RNV) and the histologic findings of EB. Furthermore, to validate the use of nuclear cardiology techniques that allow noninvasive, reliable, and rapid quantitation of ventricular function and myocardial perfusion for the diagnosis and management of rejection in patients with heart transplants. Radionuclide studies of left ventricular function were performed in 3 heterotopic heart transplant patients (HHT) with long term survival and early after the operation in 5 patients with HHT, 12 orthotopic heart transplants (OHT) and in 2 heart and lung transplants (HLT). Simultaneous EBs were performed in the early posttransplant patients and a histologic score for acute rejection was obtained. First pass (FP) and multigated equilibrium blood pool ventriculography, using the in vivo 99mTc-labelling of RBCs was used to measure left ventricular volumes (LVV) such as stroke volume (SV), end-diastolic volume (EDV), end-systolic volume (ESV), and both global and regional ejection fraction (EF, REF). The histological grading of acute rejection was classified into four groups: (1) no rejection, (2) mild rejection, (3) moderate rejection, and (4) severe rejection. The median of each LVV parameter was calculated and correlated with the EB using a nonparametric one way analysis of variance. A percentage change of LVVs was used rather than the difference of the calculated LVVs. During moderate acute rejection, SV had the highest correlation in P less than 0.004, followed by the EDV (P less than 0.05), and finally ESV (P less than 0.02). During severe acute rejection the correlation was SV (P less than 0.0008), EDV (P less than 0.001), and ESV (P less than 0.006). Myocardial perfusion scintigraphy using 201T1 was performed in the HHT patients, although, at this stage we have not attempted a correlation with the histologic findings. In one patient with long term survival OHT, increased 131I-metaiodobenzylguanidine (MIBG) myocardial uptake was evident during a rejection episode.

Adolescent↗
PubMed1988

Change from aerobic to anaerobic metabolism after brain death, and reversal following triiodothyronine therapy.

Brain-dead organ donors are depleted of circulating triiodothyronine (T3) and show features suggestive generally of anaerobic metabolism at the tissue level, accompanied by deteriorating hemodynamic function. The principle of single-bolus kinetics with labeled carbon compounds (14C-R), with subsequent measurement of both plasma activity and of exhaled 14C O2 has therefore been used to study glucose, pyruvate, and palmitate utilization under conditions of (1) sedation, (2) brain death, and (3) brain death with T3 therapy in the baboon. Serum lactate and plasma-free fatty acid concentrations were also measured. There was a major change in metabolic oxidative processes following brain death. The rate of glucose, pyruvate, and palmitate utilization was markedly reduced, and there was an accumulation of lactate and free fatty acids in the plasma, indicating a general change from aerobic to anaerobic metabolism. The administration of T3 to the brain-dead baboon resulted in a dramatic increase in the rate of metabolite utilization, and a reduction in the plasma concentrations of plasma lactate and free fatty acids, indicating an apparent reversal from tissue anaerobic to aerobic metabolism. We suggest that T3 should be administered to all brain-dead potential organ donors to correct and maintain a more physiologic metabolic status and thus to improve organ function.

Aerobiosis↗
PubMed1987

Labeling quinone-binding sites in photosynthetic reaction centers: A 38-kilodalton protein associated with the acceptor side of photosystem II.

2-Acetoxymethyl-1,4-naphthoquinone (2-AcOMeNQ) binds with rapid kinetics and high affinity to the primary quinone Q(A) site of reaction centers from Rhodopseudomonas capsulata. Binding of 2-AcOMeNQ fully restores electron-transfer activity with kinetics that is similar, but not identical, to that seen with ubiquinone-50. When bound at the Q(A) site, 2-AcOMeNQ preferentially labels the L subunit. This preference suggests that 2-AcOMeNQ labels primarily the region of a quinone-binding site that is close to the first isoprenoid unit of the side chain, which is expected from the location and structure of the reaction region of the molecule. In photosystem II particles from Synechococcus sp., 2-AcOMeNQ primarily labels two polypeptides with apparent molecular masses of 38 and 19 kDa. Labeling of only the 38-kDa polypeptide is sufficiently sensitive to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) to conclude that it is involved in binding quinones on the acceptor side of photosystem II. Although we have not yet identified the 38-kDa protein, its properties suggest that it is the D2 protein. From the DCMU-sensitive labeling and from homologies to functionally important regions of the bacterial reaction-center subunits, we propose that the 38-kDa protein is intimately involved in binding the cofactors that mediate primary photochemistry.

Journal Article↗
PubMed1986

The effect of aspirin and anti-ulcer drugs on gastric mucosal prostaglandin E.

The effect of single doses of aspirin, cimetidine, ranitidine, sucralfate, dextran, colloidal bismuth subcitrate, carbenoxolone and antacid on gastric mucosal prostaglandin E (PGE) content was studied in normal subjects. Endoscopic gastric specimens were taken from the body and antrum before and 90 minutes after drug ingestion and the PGE content was measured by radio-immunoassay. There was more PGE in the antrum than in the body (4.02 +/- 3.09 v. 2.80 +/- 2.31 ng PGE/mg protein; P less than 0.001). Aspirin, sucralfate and antacid reduced the amount of PGE in the antral mucosa (2.85 +/- 0.54-1.44 +/- 0.44; P less than 0.001; 3.04 +/- 1.01-1.94 +/- 0.74; P less than 0.03; and 5.06 +/- 0.91-3.54 +/- 0.73; P less than 0.006; ng PGE/mg protein respectively). None of the drugs had any effect on the levels measured in the body mucosa.

Adult↗
PubMed1986

Placenta praevia and sex ratio at birth.

The ratio of male to female sex among infants born to 391 women with and 114 079 without placenta praevia was analysed by parity. In the women without placenta praevia the sex ratio decreased significantly with increasing parity, whereas in the women with placenta praevia it increased. Overall, the sex ratio was increased among the women with placenta praevia, particularly multiparas. An increase in the sex ratio at birth is associated with insemination early or late in the menstrual cycle, which may result in delayed development and implantation of the blastocyst; this may be a predisposing factor in placenta praevia.

Female↗
PubMed1986

Pre-pubertal anorexia nervosa: a retrospective controlled study.

Pre-pubertal anorexia nervosa is a challenge to the explanatory powers of the many aetiological theories. This retrospective controlled study specifically compares 20 subjects with pre-pubertal anorexia nervosa to matched post-pubertal anorectic and pre-pubertal neurotic groups. The results show greater pre-morbid feeding problems in the index group and their families; both pre-pubertal groups show more behavioural problems before becoming ill. The illness is very similar in the two anorectic groups; they show comparable levels of sexual anxiety, and self-injury rates (35%) are equal. The implications of these findings for the various theories are discussed.

Age Factors↗