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Biomedical subjects

P Stephenson

Publications and source records attributed to P Stephenson.

At least 37 records · Page 2Linked to original sources
PubMed1992

Health care consequences of the European economic community in 1993 and beyond.

Generally, health services are not covered by the treaties of the European Community. However, to an increasing extent the EC has and will have an influence on national health systems. In particular the effects of regulations made for other sectors have repercussions for health. For example the free movement of labour and the harmonization initiatives have direct effects on the educational curricula for health professions and may, in time increase professional migration within the community. Within the EC research programmes health related topics have been included to an increasing extent. This goes in particular for medical informatics, standardization, quality assurance systems and pharmaceuticals. Indirect effects of the single market will probably appear within the area of insurance, public purchasing and building and other types of construction works. Other areas that probably will be influenced are record security and occupational health benefits.

Cross-Cultural Comparison↗
PubMed1992

Commentary: the public health consequences of restricted induced abortion--lessons from Romania.

The question of whether abortion should be legal is currently being decided in many countries. Although much of the discussion has focused on ethical issues, the public health consequences should not be overlooked and should be addressed realistically and responsibly. Nowhere are the public health manifestations of restricted abortion more apparent than in Romania. The pronatalist policies of the Ceaucescu regime resulted in the highest maternal mortality rate in Europe (approximately 150 maternal deaths per 100,000 live births) and in thousands of unwanted children in institutions.

Abortion, Illegal↗
PubMed1991

In vitro cleavage of an N-ras messenger-like RNA by a ribozyme.

A cDNA library was constructed in lambda gt10 from T-15 cells, a transformed mouse fibroblast line. The transforming N-ras sequence was recovered and subsequently used as a substrate for ribozyme cleavage. The design of the ribozyme was based on that of the hammerhead structure of the satellite tobacco ringspot autolytic processing sequence. Specificity to the N-ras substrate was conferred by 10 nucleotides homologous to the target site on the mRNA positioned on either side of the catalytic unit. The cleavage reaction was most efficient at higher temperatures but efficiency at lower temperatures was improved by the inclusion of urea in the reaction mixture. The ribozyme failed to cut an antisense ras sequence even at high temperature or in the presence of urea.

3T3 Cells↗
PubMed1990

Comparison of non-mydriatic retinal photography with ophthalmoscopy in 2159 patients: mobile retinal camera study.

OBJECTIVE: To determine whether non-mydriatic Polaroid retinal photography was comparable to ophthalmoscopy with mydriasis in routine clinic screening for early, treatable diabetic retinopathy. DESIGN: Prospective study of ophthalmoscopic findings according to retinal camera screening and ophthalmoscopy and outcome of referral to ophthalmologist. SETTING: Outpatient diabetic clinics of three teaching hospitals and three district general hospitals. PATIENTS: 2159 Adults selected randomly from the diabetic clinics, excluding only those registered as blind or those in wheelchairs and unable to enter the screening vehicle. MAIN OUTCOME MEASURES: Numbers of patients and eyes correctly identified by each technique as requiring referral with potentially treatable retinopathy (new vessel formation and maculopathy) and congruence in numbers of microaneurysms, haemorrhages, and exudates reported. RESULTS: Camera screening missed two cases of new vessel formation and did not identify a further 12 but indicated a need for referral. Ophthalmoscopy missed five cases of new vessel formation and indicated a need for referral in another four for other reasons. Maculopathy was reported in 147 eyes with camera screening alone and 95 eyes by ophthalmoscopy only (chi 2 = 11.2; p less than 0.001), in 66 and 29 of which respectively maculopathy was subsequently confirmed. Overall, 38 eyes received laser treatment for maculopathy after detection by camera screening compared with 17 after ophthalmoscopic detection (chi 2 = 8.0; p less than 0.01). Camera screening underestimated numbers of microaneurysms (chi 2 = 12.9; p less than 0.001) and haemorrhages (chi 2 = 7.4; p less than 0.01) and ophthalmoscopy underestimated hard exudates (chi 2 = 48.2; p less than 0.001). CONCLUSIONS: Non-mydriatic Polaroid retinal photography is at least as good as ophthalmoscopy with mydriasis in routine diabetic clinics in identifying new vessel formation and absence of retinopathy and is significantly better in detecting exudative maculopathy.

Adolescent↗
PubMed1988

MMPI-168 profiles of male narcotic addicts by ethnic group and city.

MMPI-168 profiles were obtained on 225 male narcotic addicts who were attending methadone maintenance clinics in Baltimore and New York City during 1983 and 1984. Data were collected on Black and White (Anglo, other than Hispanic) addicts in Baltimore and on Black, Hispanic, and White addicts in New York City. In general, the profiles indicated high levels of psychopathology, with particularly high elevations on the F, D, PD, PT, and Sc scales. Consistent across cities and in agreement with earlier findings, profiles of Whites indicated somewhat more maladjustment than those for Blacks, while the profiles of Hispanics displayed essentially the same levels of disturbance as those for Whites. Comparisons by city revealed greater deviance for New York City subjects, a finding more evident among Whites than among Blacks.

Ethnicity↗
PubMed1988

High esophageal stricture: a complication of "inlet patch" mucosa.

High esophageal stricture associated with a circumferential "inlet patch" of heterotopic gastric mucosa is reported in 2 patients. Biopsy specimens taken from the strictures demonstrated inflamed or ulcerated gastric fundal-type mucosa in both cases. Dilatation of the strictures followed by treatment with histamine H2-antagonists produced almost complete resolution of dysphagia in both patients.

Adult↗
PubMed1988

Differences among treatment clinic types in attitudes toward narcotic addiction.

Factor analysis of data from a general survey of attitudes and opinions concerning narcotic addiction and its treatment revealed 10 major dimensions, five of which were likely to have significant implications for drug abuse intervention strategies. For these latter dimensions, differences were determined among clients and staff according to type of treatment clinic (three types involving the provision of methadone maintenance in various combinations with other treatments and one involving the use of abstinence only). The most pronounced differences were between the methadone clinics and those offering abstinence only. Both the clients and staff of abstinence clinics were more skeptical concerning treatment effectiveness, were more negative regarding the use of narcotic drugs, and were more disposed to the use of ex-addict counselors and group procedures in treatment.

Black or African American↗
PubMed1987

Angina bullosa haemorrhagica: clinical and laboratory features in 30 patients.

Angina bullosa haemorrhagica (ABH) is a relatively recently recognized bullous disorder in which recurrent oral blood blisters appear in the absence of any identified systemic disorder. This study has examined the clinical, histologic, immunologic, and hemostatic features of 30 British patients and demonstrates that ABH is predominantly a localized disorder of middle-aged or elderly patients of either sex that is evident mainly as blood blisters on the soft palate. Trauma appears to be the most common identifiable precipitating factor, but the essential tissue defect is as yet unidentified.

Aged↗
PubMed1987

Angina bullosa haemorrhagica: lesional immunostaining and haematological findings.

The aetiology of angina bullosa haemorrhagica remains obscure. Fourteen patients with clinical features suggestive of angina bullosa haemorrhagica were investigated. Haemostatic function tests were carried out on an initial 5 patients and immunostain studies on a total of 12 patients. The results indicate that the aetiology of angina bullosa haemorrhagica is associated with neither a haemostatic defect, nor an immunopathogenic basis, and the cause is, as yet, unclear.

Aged↗
PubMed1987

Attitudes toward narcotic addiction.

In an effort to isolate the major dimensions of attitude and expectation regarding narcotic addiction and its treatment and to compare different groups of addict/clients and agency staff on these factors, a comprehensive questionnaire was administered to 900 addict/clients and 237 agency personnel in 25 drug treatment clinics in six states. Results of a factor analysis, which used questionnaire data from all of the 1137 subjects so that direct group comparisons could be made, indicated the presence of 10 major dimensions of attitude and expectation. Results also suggested considerable variation, particularly by status (client vs. staff) and ethnic group, on these dimensions. An additional analysis of staff attitudes and expectations revealed correlations with years of education, ex-addict status, and years of work experience. Such findings suggest the need to consider client/staff characteristics and attitudes in the planning of treatment services for narcotic addicts. An abbreviated (53-item) attitude and expectation questionnaire was developed for this purpose.

Adult↗
PubMed1987

Products of in vitro cleavage and polyadenylation of simian virus 40 late pre-mRNAs.

Formation of mRNA 3' termini involves cleavage of an mRNA precursor and polyadenylation of the newly formed end. Cleavage of simian virus 40 late pre-mRNA in a crude nuclear extract generated two RNAs, 5' and 3' half-molecules. These RNAs were unmodified and linear. The 5' half-molecule contained sequences upstream but not downstream of the poly(A) site and ended in a 3'-terminal hydroxyl. The 3' half-molecules comprised a family of RNAs, each of which contains only sequences downstream of the poly(A) site, and ends in a 5'-terminal phosphate. These RNAs differed only in the locations of their 5' terminus. The 3' terminus of the 5' half-molecule was the adenosine 10 nucleotides downstream of AAUAAA, at the +1 position. The 5' terminus of the longest 3' half-molecule was at +2. Thus, these two RNAs contain every nucleoside and phosphate of the precursor. The existence of these half-molecules demonstrates that endonucleolytic cleavage occurs near the poly(A) site. 5' half-molecules generated in the presence of EDTA (which blocks polyadenylation, but not cleavage) ended at the adenosine at position +1 of the precursor. When incubated in the extract under suitable conditions, they became polyadenylated. 5' half-molecules formed in 3'-dATP-containing reactions contained a single 3'-deoxyadenosine (cordycepin) residue added onto the +1 adenosine and were poor polyadenylation substrates. We infer that the +1 adenosine of the precursor becomes the first A of the poly(A) tract and provides a 3' hydroxyl group to which poly(A) is added posttranscriptionally.

Alkaline Phosphatase↗
PubMed1986

The AAUAAA sequence is required both for cleavage and for polyadenylation of simian virus 40 pre-mRNA in vitro.

The sequence AAUAAA is found near the polyadenylation site of eucaryotic mRNAs. This sequence is required for accurate and efficient cleavage and polyadenylation of pre-mRNAs in vivo. In this study we show that synthetic simian virus 40 late pre-mRNAs are cleaved and polyadenylated in vitro in a HeLa cell nuclear extract, and that cleavage in vitro is abolished by each of four different single-base changes in AAUAAA. In this same extract, precleaved RNAs (RNAs with 3' termini at the polyadenylation site) are efficiently polyadenylated. This in vitro polyadenylation reaction also requires the AAUAAA sequence.

DNA Restriction Enzymes↗
PubMed1985

Sequence of the OXA2 beta-lactamase: comparison with other penicillin-reactive enzymes.

The nucleotide sequence of the unusual plasmid-mediated OXA2 beta-lactamase is presented, and compared with other beta-lactamases. The OXA2 enzyme has similar features at the presumed active site, but no other significant regions of homology with other penicillin-reactive enzymes. The active site homology may therefore represent convergent evolution of otherwise dissimilar genes.

Amino Acids↗
PubMed1985

Graft rejection in a congenic panel of rats with defined immune response genes for class I antigens. II. Quantitative aspects of Ir gene function in a full-haplotype mismatch.

Previous studies have shown that the Ir-gene-controlled rejection of rl tissues by c/u responder and non-rejection by c low responders does not extend to tissues expressing a full a haplotype mismatch. However, antibody responses and liver graft rejection are both defective in low responders, even across a full haplotype barrier. We have therefore used a titrated adoptive transfer assay to search for quantitative differences in the responsiveness of c and c/u animals to a organ grafts. We first established that a heart graft rejection could be ablated in both recipient strains with whole-body irradiation and could be restored with syngeneic cells. Titration of restorative cells revealed that 5 times as many c cells were required to restore graft rejection in c recipients as c/u cells were required in c/u recipients. Use of cells from primed donors showed that in both c/u and c animals these cells had undergone about a 5-fold increase in potency, showing that there was no failure of proliferation and differentiation in the low responder after contact with antigens. Cross-transfer experiments were done to attempt to localize the defect in low-responder animals either to a failure of low-responder antigen-presenting cells (APC) to trigger a response or a defect in the responsiveness of alloreactive cells toward the a antigens. In these experiments c cells were obtained from radiation chimeras of the c----c/u type. These cells were used to restore graft rejection in c/u irradiated recipients. Similar experiments employing c/u cells obtained from c/u----c chimeras and given to irradiated c recipients were also done. These showed that c cells from chimeras were marginally less potent than c/u cells from chimeras. In contrast when cross-transfer of c/u cells to c animals bearing a nonrejected rl heart was done, no rejection was seen even when antigen presenting cells were cotransferred. The conclusions from this series of experiments were that quantitatively small defects were present in both repertoire and antigen presentation, and that these quantitative defects in aggregate were probably sufficient to explain the documented low responsiveness of c animals to the a haplotype. The failure of high-responder c/u cells to secure rejection of rl tissues in the low-responder c environment suggests that presentation of isolated class I differences in host APCs is mandatory for rejection to occur and is highly defective in the c animal.

Animals↗
PubMed1985

Duodenal bulb plasma cells in duodenitis and duodenal ulceration.

Using an immunoperoxidase technique IgA, IgM, IgE and IgG plasma cells were studied in endoscopic duodenal bulb biopsies taken from 14 controls, 25 patients with grade 1 duodenitis (Whitehead classification), 12 patients with grade 2 duodenitis and three with grade 3 duodenitis. The control counts were compared with those in the jejunum and rectum. In addition cell counts were compared in 16 pairs of patients, with and without duodenal ulcer, exactly matched for grade of duodenitis. The control counts were not significantly different from counts in jejunum or rectum except for IgG which were higher in the jejunum (p = 0.03). IgA plasma cell counts were significantly increased in both grade 1 and grade 2 duodenitis compared with controls (p less than 0.05 and p less than 0.01). There was no significant difference for the other plasma cells. All plasma cell counts were decreased in the small group of grade 3 duodenitis compared with the other groups. There was no significant difference between counts in duodenitis whether or not there was associated duodenal ulceration. The isolated IgA plasma cell response of the duodenal bulb mucosa in duodenitis is very different from that of the jejunal mucosa in coeliac disease, and the rectal mucosa in inflammatory bowel disease and bacterial colitis and probably represents the basic response to any mucosal damage.

Cell Count↗