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Biomedical subjects

J S Morris

Publications and source records attributed to J S Morris.

At least 109 records · Page 6Linked to original sources
PubMed1991

Effect of meal on the physiological and physicochemical actions of potassium citrate.

The effect of meals on the physiological and physicochemical actions of potassium citrate was examined in 8 patients with nephrolithiasis maintained on a constant metabolic dietary regimen. Potassium citrate (20 mEq. 3 times per day), whether given with food or on an empty stomach, significantly increased urinary pH, citrate and potassium, and decreased urinary calcium and ammonium. Moreover, potassium citrate decreased urinary saturation of calcium oxalate and uric acid, although it slightly increased that of brushite. However, there was no significant difference in these measures when the drug was given with meals from the time when it was given on an empty stomach. Thus, the effect of potassium citrate on urinary risk factors is unaffected by food.

Adult↗
PubMed1991

A comparison of renal damage induced by varying modes of shock wave generation.

To evaluate for the possible differences in the extent of pathologic injury occurring following treatment with various lithotripsy modalities, we subjected rabbits to treatment on either an electrohydraulic, electromechanical, or piezoelectric lithotripter. Functional evaluations by enzymuria failed to reveal any difference in the extent of damage between the lithotripters. Pathologic evaluation of the kidneys revealed that both electrohydraulic and electromechanical lithotripsy resulted in an increased instance of acute subcapsular hematoma and fibrosis when compared to piezoelectric treated kidneys (p less than 0.001). Despite the definitive differences noted in the acute animals, there was no significant variation in the area of permanent renal damage that occurred between the various lithotripters.

Acetylglucosaminidase↗
PubMed1991

Temporal effects of shock wave lithotripsy.

Previous studies have demonstrated that renal parenchymal injury following extracorporeal shock wave lithotripsy is dependent upon shock wave power as well as the total number of shock waves administered. In order to determine the deleterious effects of temporal versus cumulative doses of shock wave administration, adult female rabbits were divided into five groups receiving either: 1000 shock waves in one session; 2000 shock waves in one session; 2000 shock waves in two sessions, one week apart; unilateral nephrectomy without lithotripsy; or anesthesia only as control population. One month following lithotripsy, renal functional studies for gamma glutamyl transferase and N-acetyl-beta-glucosaminidase revealed persistent enzymuria in the animals treated with 2000 shocks in one session. Pathologic studies in these animals confirmed an increased area of periglomerular and intratubular fibrosis when compared to animals managed by either 1000 shocks or 2000 shocks in divided doses (p less than 0.01). These findings suggest the importance of avoiding single treatments with large doses of shock waves and favor the administration of multiple small-doses of shock waves to minimize renal damage during the treatment of patients with hard or large calculi.

Acetylglucosaminidase↗
PubMed1991

Selenium in diet, blood, and toenails in relation to human health in a seleniferous area.

To determine whether high dietary selenium intake was associated with adverse effects, selenium in diet, blood, and toenails was studied in relation to human health in adults residing in western South Dakota and eastern Wyoming. Over a 2-y period 142 subjects were recruited from households selected at random and from ranches where unusually high selenium intakes were suspected. Subjects completed health questionnaires, underwent physical examinations, provided blood samples for clinical assessment, and provided blood, urine, toenails, and duplicate-plate food collections for selenium analysis. About half of the 142 free-living subjects had selenium intakes greater than 2.54 mumol/d (200 micrograms/d) (range 0.86-9.20 mumol/d, or 68-724 micrograms/d). Physical findings characteristic of selenium toxicity were not present nor were clinically significant changes in laboratory tests or frequency of symptoms related to selenium in the blood, toenails, or diet. We found no evidence of toxicity from selenium in subjects whose intake was as high as 9.20 mumol/d (724 micrograms/d).

Adult↗
PubMed1991

Two different forms of homozygous sickle cell disease occur in Saudi Arabia.

Haematological, clinical and some molecular genetic features of homozygous sickle cell (SS) disease in Saudi Arabia have been compared in 33 patients from the Eastern Province (Eastern) and 30 from the South Western Province (Western). Eastern patients all had the Asian beta globin haplotype whereas Western patients were more variable but predominantly of the Benin haplotype. Eastern patients had more deletional alpha thalassaemia, higher total haemoglobin and fetal haemoglobin levels, and lower HbA2, mean cell volume, reticulocytes, and platelet counts. Clinically, Eastern patients had a greater persistence of splenomegaly, a more normal body build and greater subscapular skin fold thickness, and Western patients had more dactylitis and acute chest syndrome. Painful crises and avascular necrosis of the femoral head were common and occurred equally in both groups. The disease in the Eastern province has many mild features consistent with the higher HbF levels and more frequent alpha thalassaemia but bone pathology (painful crises, avascular necrosis of the femoral head, osteomyelitis) remains common. The disease in the West is more severe consistent with the Benin haplotype suggesting an African origin.

Adolescent↗
PubMed1991

A comparison of sickle cell syndromes in northern Greece.

Haematological and clinical characteristics have been examined in 30 patients with homozygous sickle cell (SS) disease, 28 with sickle cell-beta zero thalassaemia, and 21 with sickle cell-beta+ thalassaemia. The latter could be divided into three groups on their molecular basis and HbA levels, four subjects with an IVS-2 nt 745 mutation having 3-6% HbA (designated S beta+ thalassaemia type I), 14 subjects with an IVS-1 nt 110 mutation having 8-15% HbA (designated S beta+ thalassaemia type II), and three subjects with an IVS-1 nt 6 mutation having 20-25% HbA (designated S beta+ thalassaemia type III). Comparisons were conducted between SS disease, S beta zero thalassaemia, and S beta+ thalassaemia type II. Compared to SS disease, both thalassaemia syndromes had higher HbA2 levels and red cell counts and lower mean cell haemoglobin content (MCHC), mean cell volume (MCV) and MCH, and S beta zero thalassaemia had higher HbF and reticulocyte counts. Compared to S beta zero thalassaemia, S beta+ thalassaemia had a higher haemoglobin and MCHC. Clinically, persistence of splenomegaly was more common in S beta zero and S beta+ thalassaemia type II compared to SS disease. Few significant differences occurred between SS disease, S beta zero and S beta+ thalassaemia type II in Northern Greece suggesting that the 8-15% HbA in the latter condition was insufficient to modify the clinical course.

Adolescent↗
PubMed1991

Extended life span of human endometrial stromal cells transfected with cloned origin-defective, temperature-sensitive simian virus 40.

Human endometrial stromal cells transfected with an origin-defective, temperature-sensitive simian virus 40 recombinant plasmid are dependent on T-antigen function for proliferation and at the permissive temperature have an extended life span in culture. Southern blot analysis indicates that the transfected gene is present in low copy number, possibly at a single integration site. Normal stromal cells are capable of 10 to 20 population doublings in culture. Transfected cultures have been carried at the permissive temperature to 80 population doublings before crisis. In the multistep model of malignant transformation of human cells, these cells represent one of the earliest stages: extended but finite life span. We have used these cells to investigate alterations in signal transduction that may be responsible for this early stage of transformation caused by the large T antigen. Temperature shift experiments indicate that the expression of ornithine decarboxylase (ODC) but not of c-fos is altered by the large T antigen. Induction of c-fos by serum or 12-O-tetradecanoylphorbol-13-acetate is independent of temperature. However, in the transfected cells, the induction of ODC by asparagine or serum is greatly enhanced at the permissive temperature. This result indicates that the large T antigen acts downstream of c-fos but upstream of ODC expression in the signal-transducing cascade.

Antigens, Polyomavirus Transforming↗
PubMed1991

Relationship of serum copper and zinc levels to HIV-1 seropositivity and progression to AIDS.

Dietary, serum, and tissue levels of copper and zinc were determined at baseline in a cohort of homosexual men to investigate the relationship of these factors to human immunodeficiency virus type 1 (HIV-1) seropositivity and subsequent progression to AIDS. Using a nested case control design, 54 asymptomatic HIV-1 seropositives who later progressed to AIDS were compared with 54 HIV-1 seropositives who did not progress and 54 seronegatives (mean follow-up time 2.5 years). Serum levels of copper and zinc were estimated from frozen serum samples, tissue levels from stored toenail samples, and dietary intakes from a semiquantitative food frequency questionnaire administered at baseline. Neither dietary copper and zinc nor their levels in toenails were associated with HIV-1 seropositivity or progression to AIDS. However, serum copper levels were higher (p = 0.002) in HIV-1-seropositive progressors (mean = 115.6 micrograms/dl; SD = 17.1) than the seropositive nonprogressors (mean = 109.0 micrograms/dl; SD = 15.8) and the seronegatives (mean = 101.9 micrograms/dl; SD = 16.7). Conversely, serum zinc levels were lower (p = 0.016) in the seropositive progressors (mean = 85.2 micrograms/dl; SD = 11.5) than the seropositive nonprogressors (mean = 90.7 micrograms/dl; SD = 12.0) and the seronegatives (mean = 92.0 micrograms/dl; SD = 14.7). Furthermore, in a logistic regression, higher serum copper (odds ratio per 20-micrograms/dl increase = 2.23; 95% confidence interval = 1.02-4.87) and lower serum zinc (odds ratio per 20-micrograms/dl increase = 0.30; 95% confidence interval = 0.14-0.66) predicted progression to AIDS independently of baseline CD4+ lymphocyte level, age, and calorie-adjusted dietary intakes of both nutrients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1991

Acute upper gastrointestinal haemorrhage in a district general hospital: audit of an agreed management policy.

All patients from an unselected population admitted with acute upper gastrointestinal (GI) haemorrhage to a District General Hospital (DGH) were studied prospectively over one year. Before the study period a management policy was agreed between physicians and surgeons. One-hundred-and-nine patients were admitted. Sixty-eight per cent were over 60 and 17% over 80 years of age. Sixty patients bled from peptic ulcers and seven patients rebled. Endoscopic stigmata (visible vessel, adherent clot, and oozing) were useful in identifying those at increased risk of rebleeding but not as an indication for surgery. Six patients underwent surgery for peptic ulceration with one postoperative death. There were four deaths among the other patient groups giving an overall mortality of 4.6%. This audit shows a low mortality after acute upper GI haemorrhage can be achieved even in an elderly population in a DGH without the establishment of a specialist unit but with an agreed policy of management.

Acute Disease↗
PubMed1990

A prospective study of selenium status and breast cancer risk.

Low dietary intake of selenium has been proposed as a risk factor for breast cancer. To address this hypothesis, we collected toenail clippings from 62,641 women in the Nurses' Health Study cohort who were free from cancer (other than nonmelanoma skin cancer) in 1982 and 1983. The selenium concentration in nails has been shown to reflect dietary intake of selenium. During 53 months of follow-up, 434 cases of breast cancer were diagnosed among women who had submitted a set of toenail clippings, and we matched one control free from breast and other cancers to each case. The mean selenium level in toenails in the cases (0.823 microgram/g; SD, 0.197) was almost identical to that of the controls (0.821 microgram/g; SD, 0.174). After controlling for known breast cancer risk factors, the relative risk for women in the highest quintile of selenium as compared with the lowest quintile was 1.10 (95% confidence interval, 0.70 to 1.72) and there was no trend across quintiles. Results were similar for both premenopausal and postmenopausal women. Although these data do not exclude a possible influence of selenium intake before adulthood on subsequent risk of breast cancer, selenium intake later in life is not likely to be an important factor in the etiology of breast cancer.

Adult↗
PubMed1990

Comparison of homozygous sickle cell disease in northern Greece and Jamaica.

The clinical and haematological features of homozygous sickle cell (SS) disease were compared in 30 Greek and 310 Jamacian patients. Deletional alpha-thalassaemia, which modifies SS disease, is rare among Greek patients, so only Jamacian patients with four alpha-globin genes were included in the control group. Greek patients had higher total haemoglobin concentration and red cell counts, and lower mean cell haemoglobin concentration (MCHC) and reticulocyte counts. They also had a more normal body build and more adults had persistent splenomegaly. Fewer had a history of leg ulceration or priapism but more reported acute chest syndrome. The comparatively mild disease in Greek patients is consistent with less haemolysis and sickling and therefore less bone marrow expansion. In the absence of amelioriating factors such as high HbF concentration or alpha-thalassaemia, these findings may be explained by the low MCHC.

Adolescent↗
PubMed1990

The effects of dry ashing on the composition of human and animal bone.

Elemental analysis of archaeological bones, particularly for elements such as fluorine, strontium, and zinc, has been carried out for many years, with the aim of determining their age or relating their composition to diet. Bone samples are commonly dry ashed before analysis to remove organic material and render them more readily soluble. In this study, the recoveries of strontium, zinc, and nine other elements are reported for a range of ashing times and temperatures. Recoveries of sodium, potassium, fluorine, chlorine, bromine, and zinc are significantly affected by ashing under some conditions, but recoveries of strontium, calcium, magnesium, and manganese are not.

Activation Analysis↗
PubMed1990

Attempted nonoperative management of blunt renal lacerations extending through the corticomedullary junction: the short-term and long-term sequelae.

A total of 50 patients who sustained a renal laceration extending through the corticomedullary junction following blunt trauma underwent an attempt at nonoperative (expectant) management of the urological injury. Of the patients 18% could not be stabilized and they subsequently underwent emergency laparotomy. Among our stabilized patients 2 major categories existed: 1) 30 patients with vascularized renal fragments and 2) 11 in whom a fragment of the kidney was devascularized. A statistically significant difference in the length of hospital stay (p equals 0.01) and the need for delayed surgical intervention (p less than 0.001) was noted between the 2 groups. We recommend that the physician must have a heightened awareness of probable complications in patients with major renal lacerations associated with devitalized fragments and suggest that early surgical management should be considered.

Blood Pressure↗
PubMed1990

Predictors of selenium concentration in human toenails.

To assess the validity of the selenium concentration in human toenails as a measure of selenium intake and to determine other correlates of toenail selenium level, the authors examined the predictors of toenail selenium within two subgroups of a large cohort study of US women. Mean toenail selenium was higher among 38 consumers of selenium supplements (0.904 micrograms/g, standard deviation (SD) 0.217) than among 96 nonusers (0.748 micrograms/g, SD 0.149; p less than 0.001), and a dose-response relation was observed among supplement users (Spearman's r = 0.32; p = 0.05). In a second subgroup of 677 women, selenium supplement use was also associated with higher mean toenail selenium (0.906 micrograms/g, SD 0.214, among 18 users and 0.801 micrograms/g, SD 0.148, among 659 nonusers; p = 0.02), and the dose-response relation was also significant (Spearman's r = 0.50; p = 0.03). The geographic variation in toenail selenium levels was consistent with the geographic distribution of selenium in forage crops. Toenail selenium declined with age and was significantly reduced among cigarette smokers (mean = 0.746, SD 0.124, among 146 current smokers and mean = 0.817, SD 0.159, among 311 never smokers; p less than 0.001) but was not materially affected by alcohol consumption. A dietary selenium score calculated from a food frequency questionnaire failed to predict toenail selenium level, demonstrating the suspected inability of diet questionnaires to measure individual selenium intake because of the highly variable selenium composition of different samples of the same food.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Nocturnal enuresis in sickle cell haemoglobinopathies.

The prevalence of nocturnal enuresis (wet at least two nights a week) was investigated in children, aged 8, who were being followed up as part of a prospective cohort study. There were 175 children with homozygous sickle cell disease, 106 with sickle cell haemoglobin C disease, and 150 controls with a normal haemoglobin genotype. In homozygous sickle cell disease, 48 boys (52%) and 31 girls (38%) were enuretic, a significantly higher prevalence than in those with sickle cell haemoglobin C disease--five boys (10%) and 11 girls (20%)--or in normal children--16 boys (22%) and 13 girls (17%). There was no significant difference between children with sickle cell haemoglobin C disease and the normal genotype. Boys with homozygous sickle cell disease were significantly more likely to be enuretic if they came from large families; there was a similar trend for girls with homozygous sickle cell disease, although it did not reach significance. Enuresis was more common in boys with homozygous sickle cell disease who had low concentrations of fetal haemoglobin and in girls with sickle cell haemoglobin C disease who had high mean corpuscular haemoglobin concentrations. Similar associations were not shown for girls with homozygous sickle cell disease or boys with sickle cell haemoglobin C disease.

Anemia, Sickle Cell↗
PubMed1990

Risk factors for proliferative sickle retinopathy.

The prevalence, incidence, and risk factors associated with proliferative sickle retinopathy (PSR) were investigated in 786 patients with homozygous sickle cell (SS) disease and 533 patients with sickle cell haemoglobin C (SC) disease. PSR was more common in SC disease, in which there was a significant predominance of males, and it increased with age in both genotypes. In SC disease the risk of developing PSR was highest between 15 and 24 years in males, between 20 and 39 years in females, and in SS disease between 25 and 39 years in both sexes. PSR tended to be bilateral, especially in SC disease. There was no evidence of familial clustering of PSR in SC siblings, and insufficient numbers of SS siblings were available to test for clustering. Haematological risk factors associated with PSR in SS disease were a high haemoglobin in males and a low fetal haemoglobin in both sexes and in SC disease, a high mean cell volume, and a low fetal haemoglobin in females.

Adolescent↗
PubMed1989

Selenium, lycopene, alpha-tocopherol, beta-carotene, retinol, and subsequent bladder cancer.

To examine the association between serum nutrients and the development of bladder cancer we measured selenium, alpha-tocopherol, lycopene, beta-carotene, retinol, and retinol-binding protein in serum collected from 25,802 persons in Washington County, MD, in 1974. Serum samples were kept frozen at -70 degrees C. In the subsequent 12-year period, 35 cases of bladder cancer developed among participants. Comparisons of serum levels in 1974 among cases and two matched controls for each case showed that selenium was significantly lower among cases than controls (P = 0.03), lycopene was lower among cases at a borderline level of significance (P = 0.07), and alpha-tocopherol was nonsignificantly lower (P = 0.13). For selenium there was a nearly linear increase in risk with decreasing serum levels (P = 0.03). When examined by tertiles, the odds ratio associated with the lowest tertile of selenium compared to the highest tertile was 2.06. Serum levels of retinol, retinol-binding protein, and beta-carotene were similar among cases and controls. These results support a role for selenium in the prevention of bladder cancer.

Adult↗