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Biomedical subjects

E Schwartz

Publications and source records attributed to E Schwartz.

At least 199 records · Page 11Linked to original sources
PubMed1990

Performance characteristics of urine dipsticks stored in open containers.

Dip and read urinalysis is a laboratory test commonly performed by emergency physicians. Although the manufacturer states that the capped vials containing the dipsticks must be closed immediately after removal of a strip, this recommendation may not be followed in a busy emergency department. In a simple, two-part, blinded, and controlled trial the authors found that the reagents for determining leukocyte esterase, pH, protein, glucose, ketones, urobilinogen, bilirubin, and blood showed good reproducibility when fresh dipsticks were compared with dipsticks exposed to room temperature and humidity for 1 to 15 days. In contrast to this, the nitrite portion of the exposed dipsticks showed a rapid and cumulative loss of specificity over time. By the end of a week of exposure, one third of the nitrite tests gave false-positive readings. At the end of a second week, nearly three quarters gave false-positive readings for a specificity of only 28%. It is concluded that the nitrite reagent, in contrast to the other eight reagents on the Chemstrip-9 dipstick (Biodynamics, Indianapolis, IN), rapidly loses accuracy when stored in uncapped vials.

Bacteria↗
PubMed1990

Vision and hearing during deferoxamine therapy.

To determine the frequency of eye and auditory complications and their relationship to drug dosage and iron stores in patients receiving deferoxamine, we studied 52 regularly transfused patients who received deferoxamine by subcutaneous or intravenous infusion in doses from 26 to 136 mg/kg/day, and whose serum ferritin levels of 185 to 17,775 micrograms/L reflected a wide range of iron stores. Forty-nine patients (94%) had no evidence of drug-induced visual or auditory abnormalities. Symptomatic loss of vision and hearing developed in one patient; both problems improved when chelation therapy was stopped. Of the 51 symptom-free patients, one had a mild degree of macular stippling and one had a mild, bilateral, high-frequency sensorineural hearing loss. Eye and ear abnormalities in the symptom-free patients did not progress despite continuation or resumption of chelation therapy at the same dosage. Patients with ophthalmologic and audiologic abnormalities did not receive higher doses of deferoxamine and did not have lower serum ferritin levels than patients without such abnormalities. These findings demonstrate that eye and ear abnormalities during chelation therapy with deferoxamine may not occur uniformly at as high a frequency as previously reported, even in patients who receive large doses of the chelating agent or who have only modest amounts of excessive iron.

Adolescent↗
PubMed1990

Black/white comparisons of deaths preventable by medical intervention: United States and the District of Columbia 1980-1986.

Blacks in the US experience increased mortality (1113 versus 745 per 100,000 males; 631 versus 411 per 100,000 females) and decreased life expectancy (63.7 years versus 70.7 years for males; 72.3 years versus 78.1 years for females); compared to Whites. In an effort to determine if the excess mortality among Black Americans might be explained by differences in access or quality of health care services, we performed a race-specific analysis of conditions for which mortality is largely avoidable given timely and appropriate medical care. Using methodology proposed by Rutstein and Charlton, mortality due to 12 causes was evaluated including tuberculosis, cervical cancer, Hodgkin's disease, rheumatic heart disease, hypertensive heart disease, acute respiratory disease, pneumonia and bronchitis, influenza, asthma, appendicitis, hernias and cholecystitis. In the US, during 1980 to 1986, an average of 17,366 deaths and 286,813 years of potential life (YPLL) before age 65 were lost each year due to all 12 sentinel causes combined. Of these causes, hypertensive heart disease, pneumonia and bronchitis, cervical cancer and asthma accounted for the greatest number of deaths. The mortality rate for all 12 causes combined among Blacks was 4.5 times that of Whites. The highest relative rates among Blacks compared to Whites were observed for tuberculosis, hypertensive heart disease and asthma. The overall mortality rate in the District of Columbia for the selected causes was 3.7 times the national rate. Compared to national rates, statistically significant elevated rates in the District were observed for tuberculosis, hypertensive heart disease and pneumonia and bronchitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Analysis of 5' flanking regions of the gamma globin genes from major African haplotype backgrounds associated with sickle cell disease.

There are at least three major African haplotype backgrounds on which the beta s mutation arises. Sequence changes in the immediate 5' flanking area of the gamma-globin genes may account for differences in fetal hemoglobin expression among the three haplotypes. We determined the sequence from -350 to 10 bp 5' of the G gamma and A gamma fetal globin genes from one beta s-containing chromosome on each of the three major haplotype backgrounds. The Senegal chromosome had a T at -158 5' to the G gamma gene; the Benin (BEN) chromosome had an A to G change at -309 5' to the G gamma gene; and the Central African Republic (CAR) chromosome had a C to T change at -271 5' to the A gamma gene. Genomic DNA from patients with sickle cell disease was analyzed using the polymerase chain reaction and radiolabeled allele-specific oligonucleotide probes. The -309 G variant 5' to the G gamma gene is associated with BEN chromosomes, and the -271 T variant 5' to A gamma with CAR. The -309 change was also found on beta A-containing chromosomes, while the -271 change was not. The -309 change may have predated the beta s mutation on the BEN chromosome.

Anemia, Sickle Cell↗
PubMed1990

Beta-globin gene cluster haplotypes in Hb C heterozygotes.

Previous work has suggested that the beta C mutation arose on a relatively rare beta A chromosome with a unique haplotype, and these data have been used to postulate a single origin of the beta C allele. Most characteristic of this haplotype has been the absence of a Hpa I recognition site 3' to the beta-globin gene. We studied 40 patients with Hb SC, 11 with Hb AC, and one with Hb CC. Complete haplotyping was possible on 44 beta C alleles and 3' haplotyping was possible on an additional four beta C alleles. Our results support the predominence of a unique beta C haplotype which is characterized by the absence of the Hpa I site. However, one patient who was homozygous for Hb C had one beta C allele with an atypical haplotype which contained the Hpa I site. It is unclear at this time whether or not this represents a second origin of the beta C mutation.

Anemia, Sickle Cell↗
PubMed1990

The effect of oral and parenteral typhoid vaccination on the rate of infection with Salmonella typhi and Salmonella paratyphi A among foreigners in Nepal.

We studied the incidence of enteric fever among travelers and foreign residents who attended an expatriate clinic in Kathmandu, Nepal, from February 1987 to June 1988. There were 42 cases of enteric fever; 20 were caused by Salmonella typhi and 22 by Salmonella paratyphi A. Among 18 unvaccinated foreigners who had enteric fever, S typhi was isolated from 67%, and S paratyphi A from 33%, a ratio similar to the local Nepalese population. Among 22 vaccinated foreigners, S typhi was isolated from 35%, compared with 65% with S paratyphi A. Nine percent of tourists had received the oral Ty21A typhoid vaccine. However, among seven vaccinated tourists who became infected with S typhi, four (57%) had received the oral vaccine. Typhoid vaccine efficacy for tourists was calculated and showed an overall protective rate of 90% against enteric fever in general, 95% protection against S typhi, and 72% to 75% protection against S paratyphi A. We conclude that typhoid vaccine should be recommended to all travelers to the Indian subcontinent, and since S paratyphi A is the predominant cause of enteric fever among vaccinated travelers, consideration should be given to an effective vaccine against S paratyphi A when that becomes available.

Administration, Oral↗
PubMed1990

[Use of ELISA for the detection of IgG antibodies to Mycobacterium tuberculosis in the diagnosis of tuberculosis].

The presence of mycobacterial antibodies of IgG type was determined in serum, cerebrospinal fluid and pleural puncture fluid by using ELISA and soluble antigens of the strain Mycobacterium tuberculosis H37Rv. In patients suffering from tuberculosis the most frequently found titer was 1:320 and above. This titer was however found also in 30% of healthy subjects of the control group and 29% of patients with other than tuberculous disease. The sensitivity of the test was 0.7692 and its specificity 0.4594. On examining cerebrospinal fluid of patients with suspect tuberculous meningitis, positive titers of 1:640 and 1:1280 were found in two cases, while the titers of all the other patients were definitely negative. In both cases with positive titers there was also a high antibody titer in serum and additionally also culture positivity or positive biological test was evidenced. This combination of examinations allows prompt administration of antituberculous therapy in case of positivity. The results obtained in examining pleural puncture fluid and serum are open to discussion.

Adolescent↗
PubMed1990

Enteric fever among Israeli travelers in Nepal: the need for typhoid vaccination.

Enteric fever is still an endemic disease in many developing countries. Most authorities recommend typhoid vaccination for travelers from developed countries to developing countries, particularly in the Indian subcontinent. The Ministry of Health in Israel, however, does not recommend typhoid vaccination to Israeli travelers going to any developing countries. In a study undertaken at a Western-run clinic in Kathmandu, Nepal, we found the rate of typhoid fever infection to be seven times higher among 243 Israeli travelers treated at the clinic for all causes than among 2,866 other Western tourists. The typhoid vaccination rate of the Israeli tourists was 6% compared with 91% for the other Western tourists. We could not detect any differences between the Israeli tourists and the others except for the vaccination status. We conclude that the high rate of enteric fever among Israelis is due to the lack of typhoid vaccination, and we recommend typhoid vaccine for all travelers to the Indian subcontinent.

Adult↗
PubMed1990

Arthroscopic acromioplasty. Technique and results.

Of forty-four patients who were treated by arthroscopic acromioplasty from July 1984 through August 1986, forty were available for analysis. The average age was 43.2 years, and 86 per cent of them had participated regularly in sports but were disabled due to symptoms of impingement. All patients had had a minimum of six months of non-operative therapy. The final diagnoses, which were based on the findings at arthroscopy and on clinical examination, plain radiographs, and arthrograms, were Stage-II impingement in twenty-four patients, a partial-thickness tear of the rotator cuff in six, and a full-thickness tear of the rotator cuff in ten. The shoulders were scored before the operation and again at follow-up. Preoperatively, thirty-six shoulders were rated as poor and four, as fair. After a minimum follow-up of twelve months (average, seventeen months), the scores had increased in all but one patient. The result was rated good or excellent in twenty-nine (73 per cent) of the forty patients: twenty of the twenty-four who had Stage-II impingement, four of the six who had a partial-thickness tear, and six of the ten who had a full-thickness tear. The over-all average time to return to work was nine days, and the average time to return to sports was 2.4 months. Of the thirty-three patients who had participated in sports, twenty-five (76 per cent) had returned to sports activity at the time of the most recent follow-up. The average time until full recovery was 3.8 months. There were no complications, and, over-all, thirty-eight (92 per cent) of the forty patients were satisfied with the result. In four patients, the result was a failure, and three of the four had a reoperation that relieved the symptoms.

Acromioclavicular Joint↗
PubMed1989

Photoaffinity labeling of the mammalian dopamine transporter.

A high affinity (1-2 nM) radioiodinated, photoaffinity probe for the dopamine transporter, 1-(2-[bis-(4-fluorophenyl)-methoxylethyl)-4-(2-[4-azido-3- [125I]iodophenyl]ethyl)piperazine ([125I]FAPP) has been synthesized. Upon photolysis, [125I]FAPP incorporates into a striatal polypeptide of apparent Mr 62,000 as visualized by autoradiography following sodium dodecyl sulfate-PAGE. Photoincorporation of [125I]FAPP into the Mr 62,000 polypeptide was stereoselectively inhibited by various dopamine uptake agents with a potency order typical of the dopamine transporter. The glycoprotein nature of the apparent Mr 62,000 polypeptide was assessed following specific exo- and endoglycosidase treatment. The dopamine transporter appears to be associated with complex-type oligosaccharides as indexed by its susceptibility to neuraminidase but not alpha-mannosidase digestion. Complete N-linked deglycosylation of the neuronal dopamine transporter with the endoglycosidase, glycopeptidase-F, increased the electrophoretic mobility of the 62 kDa polypeptide to apparent Mr 48,000. [125I]FAPP should prove to be a useful probe for the molecular characterization of the dopamine uptake site in various tissues and under certain pathophysiological states.

Affinity Labels↗
PubMed1989

Rapid removal of excessive iron with daily, high-dose intravenous chelation therapy.

We investigated the value of high-dose intravenous iron chelation therapy with deferoxamine as an alternative to conventional subcutaneous therapy in eight patients receiving regular transfusions who had massive iron stores, including two with clinical heart disease. Six to twelve grams of deferoxamine was infused daily for 12 hours over 12 to 25 months through externalized central venous catheters or implanted reservoirs. Serum ferritin levels decreased by 56% to 99%. Liver iron concentrations, measured by magnetic susceptibility in two patients, were 1234 and 2438 micrograms/gm wet weight (22.1 and 43.6 mumol/gm wet weight) after treatment for 17 and 25 months, respectively. A patient with congestive heart failure and a patient with severe ventricular dysrhythmias no longer required cardiac medication after 12 to 24 months of chelation therapy. Three episodes of bacteremia and three episodes of cellulitis accounted for a catheter-related infection rate of 0.14 per 100 patient-days. The catheter removal rate was 0.20 per 100 patient-days. No patient experienced serious visual, auditory, or other toxicities. We conclude that in some patients receiving regular erythrocyte transfusions, high-dose intravenous chelation therapy with deferoxamine is superior to conventional subcutaneous treatment.

Adolescent↗
PubMed1989

The effect of ciprofloxacin and pefloxacin on bone marrow engraftment in the spleen of mice.

In order to investigate the in-vivo effect of ciprofloxacin and pefloxacin on bone marrow engraftment in mice, irradiated mice were transplanted with bone marrow graft (5 x 10(5) cells/mouse) obtained from syngeneic mice. Three groups of mice (30 mice in each) received a bone marrow graft incubated for 1 h with ciprofloxacin at concentrations of 0.5, 5 and 50 mg/l. Six additional groups (30 mice in each) were treated twice daily after transplantation with intra-peritoneal injections of ciprofloxacin in dosages of 25, 50 and 100 mg/kg/24 h or pefloxacin in dosages of 10 and 100 mg/kg/24 h. Evaluation of bone marrow engraftment was performed in animals injected with I125 Iodo-deoxyuridine (0.5 mu Ci/mouse) by radioactive counting of the entire spleen and also by counting visible colonies on the spleen surface. The results of this study demonstrate a statistically significant depression of bone marrow graft uptake (P less than 0.05, student t-test) in mice treated twice daily with ciprofloxacin in dosage of 100 mg/kg/24 h, a concentration far beyond the therapeutic range.

Animals↗
PubMed1989

Differentiation of bone and bone marrow infarcts from osteomyelitis in sickle cell disorders.

To determine whether imaging techniques can differentiate osteomyelitis from bone infarction in sickle cell disorders, 39 sets of bone scans (BS) and bone marrow scans (BMS) were performed on 31 patients with sickling disorders and bone pain. In addition, three patients who had either a BS or a BMS were included. Results were analyzed according to whether scans were performed three days or less (Period 1), four to six days (Period 2), or seven or more days (Period 3) after the onset of pain. Regardless of the period, all but five BMS for 34 episodes of assumed infarction showed decreased uptake. BS findings varied depending on the time interval, with none of the ten in Period 1 showing increased uptake, but all 11 in Period 3 showing increased uptake. However, in Period 2, about half of the 13 BS showed increased uptake. All three patients with osteomyelitis in Period 3 had increased uptake on BS. The BMS done in one of these patients showed decreased uptake. Three patients with cellulitis had normal BS and BMS. One patient with septic arthritis had normal BMS, but slightly increased uptake on BS. Although typical imaging patterns are present in early and late infarction (Periods 1 and 3), the patterns for late infarction may not differ from those of advanced osteomyelitis. Therefore, imaging studies are only of value in differentiating infarction from osteomyelitis when both BS and BMS are performed soon after the appearance of symptoms.

Adolescent↗
PubMed1989

Alterations in dermal collagen in ultraviolet irradiated hairless mice.

Chronic exposure of the skin to sunlight results in severe dermal connective tissue damage that is characterized by the basophilic degeneration of collagen and the accumulation of an elastotic material. The aim of this study was to identify changes in collagen (the major structural protein of the skin) in ultraviolet irradiated mouse skin using immunochemical and biochemical techniques. Specific antibodies directed against the aminopropeptide of type III procollagen were used in immunofluorescence and immunoblotting studies. Immunofluorescent staining of irradiated and nonirradiated mice skin showed that the aminopropeptide of type III procollagen was distributed throughout the dermis in a pattern similar to that observed for type I collagen. Extracts of irradiated (5 and 10 weeks) and nonirradiated skins were then subjected to immunoblotting techniques. Levels of pN alpha 1, type III procollagen (measured by radioimmunoassay) were reduced in the extracts prepared from skins of mice that were irradiated for 5 and 10 weeks. Immunoelectron microscopy verified the loss of pN alpha 1 type III procollagen in irradiated skin. Collagen fibers of nonirradiated skin demonstrated normal labeling with antibody directed against the aminopropeptide of type III procollagen. In contrast, collagen fibers of 10 week irradiated skin failed to label with this antibody. The pN alpha 1 type III collagen is known to coat type I collagen fibers of normal skin. Therefore, its absence from the surface of type I collagen fibers of irradiated skin may play a role in the development of the elastotic material.

Animals↗
PubMed1989

[Different effects of a weak static and a weak rotating magnetic field on the growth of mycobacteria].

The authors studied the effect of weak static and weak rotating magnetic field of the same intensity on the growth of some slow- and some fast-growing mycobacteria and on the course of the enzymatic reaction of iron reduction by fast-growing mycobacteria. The experiments yielded the following results: 1. Weak rotating magnetic field inhibited totally the growth of all mycobacteria tested. In the weak static magnetic field the mycobacteria exhibited, after the initial phase of growth depression, full growth comparable to that in controls. 2. The enzymatic reaction of iron reduction by mycobacteria was blocked in the weak rotating magnetic field, whereas in the weak static magnetic field the final phase of this process was comparable to the results obtained in controls.

Iron↗
PubMed1989

Comparisons of black and white smoking-attributable mortality, morbidity, and economic costs in the District of Columbia.

Cigarette smoking is generally considered to be the most important preventable cause of death in the United States. To determine the public health impact of smoking in the District of Columbia, the DC Commission of Public Health calculated smoking-attributable mortality, morbidity, and economic costs in this predominantly black population. In 1985, an estimated 933 district residents died from smoking-related diseases, resulting in 3535 years of potential life lost. Cigarette smoking contributed to approximately 13.5% of all District deaths in 1985 (N = 6921) and accounted for 30% of all deaths of persons over age 20, far exceeding the affect of other potentially preventable causes of mortality. Black residents, especially black men, shared a disproportionately greater burden of smoking-attributable mortality when compared with white residents. These smoking-attributable deaths resulted in over $110 million in direct medical and indirect morbidity and mortality costs to District of Columbia residents. The results indicate that cigarette smoking is a major contributing cause of the black-white disparity in health status in the District of Columbia.

Black or African American↗