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Biomedical subjects

S Johnson

Publications and source records attributed to S Johnson.

At least 415 records · Page 23Linked to original sources
PubMed1989

Prostaglandin stability in human milk and infant gastric fluid.

Prostaglandins are present in breast milk and may protect and maintain intestinal epithelial cell integrity in developing mammals. In view of their very short half-life in other body tissues and fluids, studies were performed to determine prostaglandin stability in milk and gastric fluid. Tritiated prostaglandins E2 and F2 alpha were incubated for 30 min in whole milk, milk cells, and milk plasma obtained from mothers delivering at term and prematurely, and in preterm infant gastric fluid. Radioactivity chromatographic analysis revealed minimal degradation of PG in milk preparations and gastric fluid. Thus, milk may serve as an effective natural medium for PG delivery to the gastrointestinal tract. The cytoprotective effect of prostaglandins on the gastrointestinal tract may be related to their stability and lack of degradation in milk and gastric digestive juices.

Dinoprost↗
PubMed1989

Drinking, drinking styles and drug use in children of alcoholics, depressives and controls.

Adolescent children of alcoholic, depressive and normal control fathers were assessed with a variety of alcohol and drug use measures. Children of alcoholics were quite similar to the other two groups with regard to alcohol consumption, reasons for drinking, attitudes toward temperate and intemperate use of alcohol, and the typical drinking context. However, children of alcoholics, both male and female, were more likely to report drug use than children of depressives or children of normal controls. These findings suggest that although children of alcoholics are at risk for the development of alcoholism, deviant drinking practices may not be discernible in adolescence.

Adolescent↗
PubMed1989

Research note: parallel reactions in rape victims and rape researchers.

In a recent study, several nurse researchers assisted in a case record review on 1,215 rape crisis center records to determine demographic predicators of sexual abuse. Despite the relatively impersonal nature of the method used in collection of data, researchers experienced highly subjective responses to the often sketchy case records both during and after the study. Some of the reactions reported by data collectors included: anger, dreams, fear of physical injury, and sleep disorders. These responses closely parallel those reported in the literature on rape victims. This research note (1) describes the reactions of the five different data collectors, (2) compares these reactions to those reported for rape victims, (3) suggests some implications for those engaged in research on potentially distressing topics, and (4) offers suggestions on how to best prepare data collectors and others for research in emotionally charged areas.

Crisis Intervention↗
PubMed1989

Swallow syncope associated with complete atrioventricular block: a case report and review of the literature.

Swallow or deglutition syncope is a very unusual but treatable disorder. A 44-year-old male presented with multiple, recurrent episodes of complete atrioventricular block associated with swallowing. Over a 24-hour period, 92 episodes of complete atrioventricular block occurring with meals were recorded by Holter monitoring. Evaluation did not demonstrate any underlying esophageal or cardiac disease. A trial of anticholinergic medications was unsuccessful. The patient's symptoms resolved following placement of a demand cardiac pacemaker. This is a rare but potentially lethal disorder that can be successfully treated if recognized. Physicians should be alerted to symptoms of lightheadedness or syncope during meals.

Adult↗
PubMed1989

The epidemiology of infection in trachoma.

Specimens for chlamydial isolation culture and direct fluorescent antibody cytology (DFA) were collected from 1671 women and children from a trachoma-endemic area in Central Tanzania. Trachoma was graded using the new World Health Organization grading scheme, and 54% of the children and 9% of the women had inflammatory trachoma (TF or TI). DFA, using the presence of five elementary bodies as the criterion for a positive test, had a sensitivity of 88.0% and a specificity of 87.5% compared to culture and a sensitivity of 54.7% and specificity of 92.8% compared to clinical diagnosis. Altogether, 52.9% of those with trachoma grade TF were positive on either or both culture and DFA versus 77.0% of those with TI. Twenty-nine isolates were serotyped; 18 were serovar A, ten were serovar B, and one was serovar Ba. Positive cultures or DFA were obtained in 6.9% of those graded clinically as not having TF or TI and in a smaller number of those without any perceptible evidence of disease. Conversely, organisms could not be demonstrated in a number of people with severe inflammation (TI) even though some became positive after multiple repeated culture. These two findings of infection without disease and disease without evidence of infection suggest the importance of the immunologic response to infection in determining the clinical status. DFA was found to be an appropriate test for future field studies of trachoma. Further studies of those with disease but without agent and of those with agent but without disease will help understand the dynamics of infection and transmission and the role of the immune response in this important blinding disease.

Adolescent↗
PubMed1989

Antibacterial activity of norfloxacin against bacterial isolates from the urinary tract.

Two hundred fourteen isolates from clinical specimens were tested in vitro to determine their susceptibility pattern against norfloxacin. Of the 151 strains of gram-negative bacteria tested, 149 (98.7%) were susceptible. Sixty-three (100%) of the gram-positive bacteria tested were also susceptible to norfloxacin. Norfloxacin showed excellent activity against all bacteria isolated from urine.

Drug Resistance, Microbial↗
PubMed1988

Single-chain antigen-binding proteins.

Single-chain antigen-binding proteins are novel recombinant polypeptides, composed of an antibody variable light-chain amino acid sequence (VL) tethered to a variable heavy-chain sequence (VH) by a designed peptide that links the carboxyl terminus of the VL sequence to the amino terminus of the VH sequence. These proteins have the same specificities and affinities for their antigens as the monoclonal antibodies whose VL and VH sequences were used to construct the recombinant genes that were expressed in Escherichia coli. Three of these proteins, one derived from the sequence for a monoclonal antibody to growth hormone and two derived from the sequences of two different monoclonal antibodies to fluorescein, were designed, constructed, synthesized, purified, and assayed. These proteins are expected to have significant advantages over monoclonal antibodies in a number of applications.

Amino Acid Sequence↗
PubMed1988

Immunosuppression with azathioprine and prednisone in recent-onset insulin-dependent diabetes mellitus.

We randomly assigned 46 patients (mean age, 11.7 years; range, 4.5 to 32.8) with newly diagnosed insulin-dependent diabetes mellitus within two weeks of beginning insulin to receive either corticosteroids for 10 weeks plus daily azathioprine for one year or no immunosuppressive therapy. Half the 20 immunosuppressed patients completing the one-year trial had satisfactory metabolic outcomes (hemoglobin A1c less than 6.8 percent; stimulated peak C peptide greater than 0.5 nmol per liter; insulin dose less than 0.4 U per kilogram of body weight per day) as compared with only 15 percent of the controls. Three of 20 immunosuppressed patients, but no controls, were insulin independent at one year. Two of these continue to receive azathioprine without insulin after more than 27 months of follow-up. The response to immunosuppression correlated with older age, better initial metabolic status, and lymphopenia (less than 1800 lymphocytes per cubic millimeter) resulting from immunosuppression. The side effects of azathioprine included vomiting in one patient and mild hair loss in several others. Prednisone use resulted in a transient cushingoid appearance, weight gain, and hyperglycemia. The growth rate remained normal in all patients. We conclude that early immunosuppression with short-term use of corticosteroids plus daily azathioprine can improve metabolic control in some patients with insulin-dependent diabetes mellitus, but results from this unblinded study are preliminary and require further confirmation and long-term follow-up.

Adolescent↗
PubMed1988

Epidemiological considerations of the present status and future growth of the acquired immunodeficiency syndrome epidemic in South Africa.

Limited epidemiological data on acquired immunodeficiency syndrome (AIDS) and human immunodeficiency virus (HIV) infection have been assembled by voluntarily reported AIDS figures, blood donor serum prevalence and high-risk sentinel population and random background population sero-prevalence studies. The HIV epidemic in South Africa can thus be shown to consist of four separate epidemics of which the heterosexual epidemic will undoubtedly constitute the major growth in this country. Intervention must be directed to shrinking the promiscuous core which sustains this epidemic by directing attention at female prostitution and limiting the reproductive rate of the epidemic by energetic and professionally directed education at an early stage of a child's school career. Sexually transmitted diseases will play a major role in the determination of the extent of the heterosexual epidemic.

Acquired Immunodeficiency Syndrome↗
PubMed1988

A simplified automated procedure for generation of human lymphokine-activated killer cells for use in clinical trials.

The administration of lymphokine-activated killer (LAK) cells along with interleukin-2 (IL-2) can mediate regression of tumors in selected patients. A closed automated system utilizing commercial blood cell separators has been developed for washing and Ficoll-Hypaque (FH) separation of lymphocytes, for lymphocyte culture in polyolefin bags, and for concentration of LAK cells out of culture prior to infusion. We now demonstrate that preparation of LAK cells can be simplified by elimination of the FH sedimentation step. Patient leukapheresis was performed using Fenwal CS-3000 blood cell separators, with a mean cellular yield per procedure of 54 X 10(9) WBC (95% lymphocytes), 184 X 10(9) RBC, and 306 X 10(9) platelets (n = 22). These cells were then washed in the same apheresis kit with a counter-current flow of saline, thereby eliminating 85% of platelets while retaining 88% of WBC. Aliquots of the washed cells were separated on FH gradients in 50 ml centrifuge tubes, and both FH-separated and washed-only cells were cultured at 3 X 10(6)/ml with 1500 U/ml IL-2 in polyolefin bags. Cytotoxicities of 22 preparations of LAK cells from 14 patients were evaluated in 4 h 51Cr release assays. Cells that were washed-only averaged 47, 35, and 9 lytic units/10(6) cells against K562, Daudi, and fresh tumor, while FH separated cells averaged 46, 33, and 6 lytic units/10(6) cells respectively. Cellular recoveries using the wash-only technique were 25% greater than when using FH sedimentation. Omission of FH separation saves time and expense in preparation and provides greater numbers of LAK cells for use in adoptive immunotherapy.

Autoanalysis↗
PubMed1988

Prostatism: how useful is routine imaging of the urinary tract?

The clinical effects of routinely imaging the renal tract (by intravenous urography and ultrasonography) were evaluated prospectively in 128 consecutive patients with prostatism. Patients with haematuria, previous renal disease, or infection were excluded. Urologists completed a standard questionnaire in the patient's notes stating the diagnosis and the intended management. The patient then had intravenous urography and abdominal ultrasonography, urine was analysed, and plasma urea and serum creatinine concentrations and acid phosphatase activity were determined. From six months to a year later the eventual management was compared with the intended management to see the effect of these routine investigations on the outcome. For four out of 28 patients whose management was intended to be conservative the decision was changed; for only three of them was this because of the results of urography, ultrasonography, and biochemical determinations. For 31 patients the management was to be decided by cystoscopic findings, and for none of these was the final decision altered by the results from the investigations after the initial consultation. Similarly for five patients who were assessed urodynamically the final management was not changed by the results of these investigations. The planned management was changed in three of the remaining 64 patients but not because of the results of the initial investigations. Thus no indication was found for either routine urography or ultrasonography, but the total abandonment of imaging of the renal tract would be unwise. Patients scheduled for conservative management (about a quarter of the patients in this study) should have ultrasonography to detect unsuspected hydronephrosis, but in all other patients urography or ultrasonography, or both, is an unhelpful ritual. Moreover, urography is becoming more expensive, and has a recognised (albeit small) mortality.

Aged↗
PubMed1988

Phase II trial of idarubicin in patients with advanced lymphoma.

A phase II trial of idarubicin was performed in 24 patients with advanced lymphoma. The drug was administered in a dose of 10-15 mg/m2 i.v. or 15-70 mg/m2 p.o. (single dose) every 3 weeks. There were four partial responses and four minor responses. All but one of the responders had received prior doxorubicin therapy. The toxicities were myelosuppression, nausea and vomiting, and alopecia. Two patients with compromised cardiac function were observed to have further deterioration in the ejection fraction as measured by gated cardiac scan after idarubicin therapy. Further assessment of the activity of idarubicin against lymphoma is recommended in less heavily pretreated patients. The cardiac toxicity should be carefully monitored in future studies.

Antibiotics, Antineoplastic↗
PubMed1988

Progression of coronary artery disease after percutaneous transluminal coronary angioplasty.

Thirty-nine patients underwent coronary arteriography 1 to 20 months (mean 7 months) after percutaneous transluminal coronary angioplasty (PTCA). At the time of the repeat study, 35 patients (90%) had recurrent angina or myocardial infarction, and 4 patients (10%) were asymptomatic. Restenosis, defined as greater than 50% loss of PTCA gained diameter, was found in 19 patients (49%). In addition, 20 patients had new lesions or marked progression of existing lesions (defined as greater than 20% or increasing greater than 20% obstruction in coronary diameter) in the previously normal or mildly diseased coronary segments. The new or progressive lesions occurred both in patients with restenosis at the PTCA site (nine of 19) and in patients without restenosis (11 of 20). New or progressive lesions tended to occur more commonly in the artery on which PTCA was performed (13 of 40) than in the artery that did not have PTCA (10 of 77) (p less than 0.02 by chi 2). In arteries that had PTCA, new or progressive lesions occurred more often in the segment proximal to the angioplasty site (seven of 13 or 54%) than in the peri-PTCA segment (two of 13 or 15%) and in the segments distal to it (four of 13 or 31%), but this observation did not reach statistical significance. No other clinical, angiographic, or PTCA procedure variables affected the occurrence of new or progressive lesions. In patients with recurrent angina or myocardial infarction after PTCA, both restenosis and new or progressive lesions are common. New lesions or marked progression of existing lesions tended to occur in the vessel subjected to PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Cell-mediated immunity of healthy adult Nova Scotians in various age groups compared with nursing home and hospitalized senior citizens.

We used the Multitest CMI to define the delayed-type hypersensitivity response (DTH) of 149 healthy adult Nova Scotians (49 male and 100 female subjects, ranging in age from 25 to 82 years) and to define and compare the response of the healthy senior citizens (66 to 82 years old) with 79 self-sufficient senior citizens in a nursing home, 25 senior citizens in a nursing home but not self-sufficient, and 15 senior citizens hospitalized in an acute care hospital. The DTH response decreased with increasing age and with increasing dependency in a nursing home. Thus, 1.5%, 9.5%, 17.9%, 41.8%, 60%, and 40%, respectively, of the subjects in the groups listed above were anergic. For the healthy subjects, age and sex were significant factors in predicting a positive response to the skin test antigens. Use of a logistic model revealed that for male subjects, the probability of a positive response was Ln (p/1 - p) = 1.72 - 0.038 (age), whereas for female subjects, it was Ln (p/1 - p) 0.59 - 0.0213 (age). When this model was applied to the responses of senior citizens, those living at home had a significantly greater response than did those in nursing homes. Furthermore, those self-sufficient while they were living in a nursing home had a significantly greater response than those who were not self-sufficient.

Adult↗
PubMed1988

Resonance Raman spectra of bovine liver catalase: enhancement of proximal tyrosinate vibrations.

Resonance Raman spectra of native bovine liver ferri-catalase have been obtained in the 200-1800 cm-1 region. Excitation at a series of wavelengths ranging from 406.7 to 514.5 nm has been used and gives rise to distinct sets of resonance Raman bands. Excitation within the Soret and Q-bands of the heme group produces the expected set of polarized and nonpolarized porphyrin modes, respectively. The frequencies of the porphyrin skeletal stretching bands in the 1450-1700 cm-1 region indicate that catalase contains only five-coordinate, high-spin heme groups. In addition to the porphyrin modes, bovine liver catalase exhibits bands near 1612 and 1520 cm-1 that are attributable to ring vibrations of the proximal tyrosinate that are enhanced via resonance with a proximal tyrosinate----Fe(III) change transfer transition centered near 490 nm. Similar bands have been observed in mutant hemoglobins that have tyrosinate axial ligands and in other Fe(III)-tyrosinate proteins. No resonance Raman bands have been observed that can be attributed to degraded hemes. The spectra are relatively insensitive to pH over the range of 5-10, and the same spectra are observed for catalase samples that do and do not contain tightly bound NADPH. Resonance Raman spectra of the fluoride complex exhibit porphyrin skeletal stretching modes that show it to be six coordinate, high spin, while the cyanide complex is six coordinate, low spin. Both the azide and thiocyanate complexes, however, are spin-state mixtures with the high-spin form predominant.

Animals↗