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Biomedical subjects

S Johnson

Publications and source records attributed to S Johnson.

At least 379 records · Page 21Linked to original sources
PubMed1991

Diabetes education in the primary care setting.

Most diabetes education occurs in primary care settings and its effectiveness is often dependent upon a therapeutic patient-provider relationship. Providers must assess the patient's knowledge about and willingness to comply with treatment. A written contract with specific goals and behaviors may facilitate the learning and records of education sessions provide the means to monitor and evaluate progress through the educational process. Recommendations for choosing a formal diabetes education program are also included.

Diabetes Mellitus↗
PubMed1991

Localization of the translocation breakpoint in a female with Menkes syndrome to Xq13.2-q13.3 proximal to PGK-1.

Menkes syndrome is a rare X-linked recessive disorder characterized by an inability to metabolize copper. A female patient with both this disease and an X; autosome translocation with karyotype 46,X,t(X;2)(q13;q32.2) has previously been described. The translocation breakpoint in Xq13 coincides with a previous assignment of the Menkes gene at Xq13 by linkage data in humans and by analogy to the mottled mutations which are models for Menkes disease in the mouse. Therefore, this translocation probably interrupts the gene for Menkes syndrome in band Xq13. We describe here experiments to precisely map the translocation breakpoint within this chromosomal band. We have established a lymphoblastoid cell line from this patient and have used it to isolate the der(2) translocation chromosome (2pter----2q32::Xq13----Xqter) in human/hamster somatic cell hybrids. Southern blot analyses using a number of probes specific for chromosomes X and 2 have been studied to define precisely the location of the translocation breakpoint. Our results show that the breakpoint in this patient--and, therefore, likely the Menkes gene--maps to a small subregion of band Xq13.2-q13.3 proximal to the PGK1 locus and distal to all other Xq13 loci tested.

Animals↗
PubMed1991

OSHA bloodborne pathogens standard. Implications for the occupational health nurse.

The Occupational Safety and Health Administration (OSHA) has promulgated a standard, expected to become mandatory in mid 1991, designed to protect employees from all exposure to blood and other potentially infectious materials. Employers should begin now to institute an infection control plan. Methods of compliance of the standard include: universal precautions, engineering and work practice controls, personal protective equipment, and housekeeping. The occupational health nurse should coordinate development, maintenance, and revision of a program to comply with the OSHA regulations. The occupational health nurse should also educate management about the hazards of bloodborne pathogens and assist them in complying with the final standard so that a safe and healthy work environment can be achieved.

Blood↗
PubMed1990

Vaccination status and seroprevalence of measles and polio antibodies in 1-6-year-old children in the Elim health ward of Gazankulu.

Seroprevalence was used to evaluate the vaccination programme in the Elim health ward of Gazankulu. Antibodies to measles and polio were measured in 1-6-year-old children together with vaccination status. In 224 children studied using a cluster sampling technique, vaccine coverage was found to be 86% for measles and over 90% for polio and diphtheria, pertussis and tetanus. It was difficult to determine vaccine failure rates accurately; 21% of children were seronegative after having received measles vaccine, 32% who had apparently not been vaccinated had antibodies, while a total of 27% had no measles antibodies. Thirty-nine per cent of children failed to demonstrate antibodies to all 3 types of poliovirus after having received 3 doses of oral polio vaccine, 94% had immunity against type 2, and 76% and 74% were immune to types 1 and 3, respectively. Reasons for diminished effectiveness of vaccination programmes are cited; in this study it was probably due to decreased vaccine efficacy related to inadequacies in the cold-chain. Recommendations are that seroprevalence studies are useful, but only after vaccine coverage and the cold-chain have been optimised.

Antibodies, Viral↗
PubMed1990

In vivo tumor targeting of a recombinant single-chain antigen-binding protein.

We describe here the first in vivo targeting of tumors with a single-chain antigen-binding protein. The molecule, which was constructed and expressed in Escherichia coli, is a novel recombinant protein composed of a variable light-chain (VL), amino acid sequence of an immunoglobulin tethered to a variable heavy-chain (VH) sequence by a designed peptide. We show that this protein, derived from the DNA sequence of the variable regions of the antitumor monoclonal antibody B6.2, has the same in vitro antigen-binding properties as the B6.2 Fab' fragment. Comparative pharmacokinetic studies in athymic mice demonstrate much more rapid alpha and beta phases of plasma clearance for the single-chain antigen-binding protein than for the Fab' fragment, as well as an extremely rapid whole-body clearance. Half-life values for alpha and beta phases of single-chain antigen-binding protein clearance were 2.4 minutes and 2.8 hours, respectively, versus 14.8 minutes and 7.5 hours for Fab'. Furthermore, the single-chain antigen-binding protein molecule did not show accumulation in the kidney as did the Fab' molecule or, as previously shown, the F(ab')2 molecule. Despite its rapid clearance, the single-chain antigen-binding protein showed uptake in a human tumor xenograft comparable to that of the Fab' fragment, resulting in tumor to normal tissue ratios comparable to or greater than those obtained with the Fab' fragment. These studies thus demonstrate the in vivo stability of recombinant single-chain antigen-binding proteins and their potential in some diagnostic and therapeutic clinical applications in cancer and other diseases.

Amino Acid Sequence↗
PubMed1990

Nosocomial Clostridium difficile colonisation and disease.

To assess the risk of acquiring Clostridium difficile diarrhoea or colitis in patients colonised with C difficile, rectal swabs taken weekly for 9 weeks from patients with long-term (at least 7 days) hospital stays on three wards were cultured for C difficile. 60 (21%) of 282 patients were culture-positive for C difficile during their hospital stay, of whom 51 were symptom-free faecal excretors. C difficile diarrhoea developed in the other 9 patients; 2 were culture-positive for C difficile and had diarrhoea at the time of first culture, and 7 had diarrhoea or pseudomembranous colitis after 1-6 previously negative weekly rectal cultures. All patients with diarrhoea were on one ward, but symptom-free, excretors were found on all wards. HindIII chromosomal restriction endonuclease analysis (REA) of the C difficile isolates revealed 18 distinct types. All isolates from the patients with diarrhoea were one of two nearly identical REA types, B or B2. 26 of the 29 total B/B2 isolates were from patients on the same ward, which points to a nosocomial outbreak. The symptom-free excretors were not at increased risk of subsequent clinical illness.

Aged↗
PubMed1990

Considerations on the further expansion of the AIDS epidemic in South Africa--1990.

An epidemiological composite of the human immunodeficiency virus (HIV) epidemic in South Africa was constructed from reported acquired immunodeficiency syndrome (AIDS) figures, blood donor seroprevalence data and a family of active surveillance studies in the Johannesburg area. Of great concern is the extensive and continuing silent spread of HIV in the urban black population, manifested by doubling times in male and female sexually transmitted disease (STD) clinic attenders of 10.67 and 9.78 months respectively, a doubling time in female family planning (FP) attenders of 6.55 months, and HIV infection rates of 1:56, 1:37 and 1:91, respectively. These data suggest a spread of infection far more extensive than the relatively lower AIDS figures. However, seroprevalence figures in municipal employees of mainly rural origin were considerably lower, only 1:1,250 in black men and none in women, but regular movements between urban and rural areas could well introduce and amplify infection in rural areas. A complete epidemiological picture of HIV can only be attained by employing both the above approach of the family of surveys complemented by a nationwide seroprevalence study to assess HIV penetration into the general 'background' population. Educational interventions should now be particularly targeted to the major risk groups in the urban black heterosexual community.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Susceptibility to poliomyelitis, measles, mumps and rubella in university students.

A serological study of 433 university students in various health care professions revealed levels of susceptibility of 2-7% for measles, 0-4% for mumps, 6-17% for poliomyelitis and a particularly disquieting 13-23% for rubella. Representing a developed population with a supposedly high level of immunisation cover these levels of susceptibility indicate students' vulnerability to outbreaks caused by viruses coming from reservoirs in under-immunised developing populations in the country. Nevertheless, no evidence of occupational exposure between the first- and final-year students was revealed. Immunisation efforts thus need to be urgently targeted not only to developing but also to developed populations in South Africa.

Adolescent↗
PubMed1990

The effects of shear stress on endothelial cell retention and function on expanded polytetrafluoroethylene.

We evaluated the adherence of indium 111-radiolabeled endothelial cells to fibronectin-treated expanded polytetrafluoroethylene surfaces exposed to high (437 s-1) vs low (218 s-1) shear and the influence of shear on prostacyclin production. Canine jugular vein factor VIII-positive endothelial cells in passages 3 through 6 were incubated with 111Indium-oxine, and labeled cells were seeded onto fibronectin-treated expanded polytetrafluoroethylene patches. Patches with confluent cells were exposed to shear in a Weissenberg rheogoniometer for intervals ranging up to 60 minutes. Percent endothelial cell retention was determined by gamma counting of patches and media and by histologic evaluation. Prostacyclin production (tritiated radioimmunoassay of 6-keto-prostaglandin F1 alpha) was assayed on perfusing media. Results showed no differences in 6-keto-prostaglandin F1 alpha production between shear rates or time periods. Endothelial cell retention did not differ between the shear rates. Rotational shear caused persistent cell loss over time in either high- or low-shear conditions. This persistent cell loss in response to steady rotational shear differs from that in response to identical rates of pulsatile linear shear in our laboratory where cell loss approached zero after 15 minutes.

Animals↗
PubMed1990

Prospective, controlled study of vinyl glove use to interrupt Clostridium difficile nosocomial transmission.

PURPOSE: Despite recognition that Clostridium difficile diarrhea/colitis is a nosocomial infection, the manner in which this organism is transmitted is still not clear. Hands of health care workers have been shown to be contaminated with C. difficile and suggested as a vehicle of transmission. Therefore, we conducted a controlled trial of the use of disposable vinyl gloves by hospital personnel for all body substance contact (prior to the institution of universal body substance precautions) to study its effect on the incidence of C. difficile disease. PATIENTS AND METHODS: The incidence of nosocomial C. difficile diarrhea was monitored by active surveillance for six months before and after an intensive education program regarding glove use on two hospital wards. The interventions included initial and periodic in-services, posters, and placement of boxes of gloves at every patient's bedside. Two comparable wards where no special intervention was instituted served as controls. RESULTS: A decrease in the incidence of C. difficile diarrhea from 7.7 cases/1,000 patient discharges during the six months before intervention to 1.5/1,000 during the six months of intervention on the glove wards was observed (p = 0.015). No significant change in incidence was observed on the two control wards during the same period (5.7/1,000 versus 4.2/1,000). Point prevalence of asymptomatic C. difficile carriage was also reduced significantly on the glove wards but not on the control wards after the intervention period (glove wards, 10 of 37 to four of 43, p = 0.029; control wards, five of 30 to five of 49, p = 0.19). The cost of 61,500 gloves (4,505 gloves/100 patients) used was $2,768 on the glove wards, compared with $1,895 (42,100 gloves; 3,532 gloves/100 patients) on the control wards. CONCLUSIONS: Vinyl glove use was associated with a reduced incidence of C. difficile diarrhea and is indirect evidence for hand carriage as a means of nosocomial C. difficile spread.

Clostridioides difficile↗
PubMed1990

Munchausen syndrome by proxy: a family affair.

Munchausen syndrome by proxy is an unusual form of child abuse: a child presents with an illness that has been factitiously produced by a parent, typically the mother. A case of chronic illicit insulin administration to a one-year-old girl is described. Despite temporary separation of the child from the mother and long-term psychiatric intervention, factitious illnesses continued, including urine specimen contamination, laxative-induced diarrhea, suspected bladder catheterization, and suspected poisoning. Retrospective review of the medical records of the mother and two siblings demonstrated previously unrecognized evidence of factitious illnesses. The medical records contained evidence of 30 separate episodes of suspected or documented factitious illness in these four members of the same family. This unique family illustrates the significant morbidity of Munchausen syndrome by proxy and a poor response to psychiatric treatment.

Child Abuse↗
PubMed1990

Encephalitis in a 13-year-old boy following 17D yellow fever vaccine.

We report a case of encephalitis following yellow fever vaccine in a healthy 13 year-old-boy. This is the first reported case in a child older than 3 years of age and the second over the age of 9 months, before which time the vaccine is contraindicated for routine immunisation.

Adolescent↗
PubMed1990

Clostridium difficile diarrhea and colonization after treatment with abdominal infection regimens containing clindamycin or metronidazole.

One hundred fifty-six patients with presumed or documented abdominal infections were treated with amikacin/metronidazole/placebo (Group 1, 56 patients), amikacin/clindamycin/placebo (Group 2, 57 patients), or amikacin/clindamycin/ampicillin (Group 3, 43 patients) to determine both the therapeutic efficacy of the various regimens and the type of complications due to Clostridium difficile. C. difficile diarrhea occurred in 15 of 156 patients (9.6%), and C. difficile colonization occurred in 14 of 156 patients (9%) during treatment and 30 days of follow-up. The number of C. difficile diarrhea cases in Group 1 (3 of 56) was significantly lower than in Group 2 (9 of 57, p less than 0.05), but not in Group 3 (3 of 43). Exclusion of all patients who received other antibiotics in the 30-day poststudy period revealed no C. difficile diarrhea or colonization in Group 1 (0 of 13) and an acquisition rate of 31% (14 of 45) with the regimens containing clindamycin (p less than 0.02). Successful treatment outcomes (106 evaluable patients) were not statistically different among the three groups (Group 1, 64%; Group 2, 76%; and Group 3, 88%), but these data were difficult to interpret because, by chance, significantly more patients in Group 1 had bacteremia at entry (p less than 0.01), and patients in Group 3 had significantly more biliary tract infections (p less than 0.02) and significantly more favorable acute physiology scores (p less than 0.05). Use of metronidazole can reduce complications related to C. difficile, particularly if additional antimicrobials other than aminoglycosides are avoided.

Abdomen↗
PubMed1990

Improvement of oncology education at the University of Washington School of Medicine, 1984-1988.

In 1984, performance on the National Board of Medical Examiners (NBME) examination by medical students from the University of Washington School of Medicine was significantly lower in clinical oncology, pathology, surgery, and oncology-related subjects than was their performance in other subjects (p = .002) and inversely proportional to the degree of oncology-relatedness of the material examined. Moreover, their performance on oncology-related questions was significantly lower than the national average (p less than .001). The curriculum committee thus initiated a review of the oncology content in the curriculum of the school of medicine and implemented a two-year plan in 1984-1986 to improve the perceived deficiencies. During the year the two-year intervention was completed, reevaluation demonstrated evidence that substantial improvement had occurred in oncology performance by the students, relative to their performance in non-oncology subjects (p less than .05) and to the national average. Performance on the non-oncology items was unchanged. The authors conclude that oncology education and performance of the students was significantly improved within two years, after instituting the short-term plan to enhance cancer education in the medical school, the improvement in oncology did not occur at the expense of a reduction in performance in non-oncology subjects, and the improved performance in oncology by the students enhanced their overall performance on the NBME examination.

Academic Medical Centers↗
PubMed1990

Measles, mumps and rubella immunization at nine months in a developing country.

The antibody responses and reactogenicity of a measles, mumps and rubella vaccine in 9-month-old and 15-month-old black children in South Africa were compared. The antibody response to the measles component was marginally better in the older group, but no differences were observed in the response to the mumps and rubella components. Reactogenicity was similar in the two age groups. Therefore it is possible that a trivalent measles, mumps and rubella vaccine can safely and effectively replace routine measles immunization at 9 months of age in this population. Whether routine immunization policy should incorporate such a vaccine depends on the extent of acceptance of measles vaccination. In urban populations of developing countries with high rates of measles immunization, routine vaccination at 9 months might interrupt circulating wild type rubella and provide sufficient herd immunity to protect susceptible women of childbearing age. It also should decrease significantly the complications associated with wild type mumps infection. The replacement of measles vaccine by a trivalent vaccine may be very cost-effective.

Black or African American↗