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Biomedical subjects

S Whittaker

Publications and source records attributed to S Whittaker.

At least 73 records · Page 4Linked to original sources
PubMed1991

Needle-use practices among intravenous drug users in an area where needle purchase is legal.

Needle-use practices of intravenous drug users (IVDUs) were examined in a region (Seattle, King Country, Washington State, USA) where needle purchase is legal. IVDUs in treatment (n = 313) were administered extensive structured interviews concerning drug and injection equipment-use practices. Of the 80.2% reporting intravenous drug use in the previous year, 78.3% reported sharing needles. Of the 47.7% reporting intravenous use in the previous 30 days, only 40.5% shared needles, with 59.3% sharing with only one other person. Most needle-sharing partners were very well known (63%) or well known (17%) to the subjects. The most frequent method for obtaining needles was 'buying in a drug store', ranked first by 65% of the sample. Subjects whose primary source was 'buying in a drug store' shared equipment less frequently during drug-use events in the previous year (mean: 16.2%) than those with other primary sources (mean: 28.5%). Compared with findings from other regions where needle purchase and possession are illegal without a prescription, fewer subjects in the current investigation shared needles, and those who did shared with a smaller number of people. The apparent association between legalized injection equipment and reduced sharing of equipment among IVDUs should be further examined in longitudinal studies of needle-sharing before and after legalization is instituted.

Adult↗
PubMed1991

Analysis of beta, gamma, and delta T-cell receptor genes in lymphomatoid papulosis: cellular basis of two distinct histologic subsets.

To investigate the histogenesis of lymphomatoid papulosis (LYP), we have analyzed the configuration of the beta, gamma, and delta T-cell receptor (TCR) and Ig genes in DNA from 31 biopsies of 18 patients with this condition and also from peripheral blood mononuclear cells of eight of these patients. Immunoglobulin genes were in a germ-line configuration in all patients, and TCR genes were in a germ-line configuration in six patients. In nine patients, one or two rearranged bands (RB) were detected with both beta and gamma TCR probes and in one patient with beta, gamma, and delta TCR probes. Two patients, in whom beta and delta TCR genes were in a germline configuration, had evidence of multiple discrete rearrangements of gamma TCR genes, consistent with a polyclonal T-cell population. Analysis of multiple biopsies revealed that RB, when present, were identical in different lesions from individual patients. All but one of the peripheral blood samples showed a germ-line configuration. The exception had evidence of a rearrangement of gamma and delta in peripheral blood and a beta and gamma rearrangement within tissue. This study has established that only a proportion of patients with LYP have a monoclonal T-cell proliferation. Correlation with the clinicopathologic and immunophenotypic data revealed that a T-cell clone was limited to patients with Willemze type B LYP or "mixed type" LYP, whereas patients with type A LYP consistently showed a germline configuration of TCR genes. This study indicates that in LYP the atypical hyperchromatic cerebriform mononuclear cells of type B invariably constitute a monoclonal T-cell population whereas the atypical CD30 positive type A cells represent a proliferation of cells of non-B, non-T-cell lineage.

Adult↗
PubMed1991

Overt and covert parental conflict and adolescent problems: observed marital interaction in clinic and nonclinic families.

When adolescents behave in socially unacceptable ways, overt interparental conflict is widely held to be the cause. Empirical studies, however, have been inconsistent in supporting this assumption. Some researchers therefore have speculated that covert conflict also plays a role. In the current observational study, evidence was found that both overt parental conflict and some forms of covert conflict play roles. During problem-solving family discussions, parents of adolescents whom they had brought into an outpatient clinic for treatment overtly disagreed with each other significantly more often than did parents with adolescents who did not require treatment. Families of clinic adolescents also exhibited significantly more silence during their discussions, and mothers spent significantly less time talking than did their nonclinic counterparts. The implications that both the overt and covert conflict may have for adolescent behavior are discussed.

Adolescent↗
PubMed1991

Sexual behaviors of intravenous drug users in treatment.

Sexual behaviors of a group of 313 intravenous drug users (IVDUs) (225 men, 88 women) were assessed by a structured interview at the start of an AIDS prevention project. Although the majority were celibate or monogamous during the prior year (men 52.5%, women 64.3%), many IVDUs had multiple sexual partners in that time, including 19.6% of men and 7.2% of women reporting five or more. Married male and female IVDUs were more likely to have multiple sexual partners than married people in general population samples. Only 38.5% of male and 35.4% of female IVDUs ever used condoms during the previous 5 years. Percentage of sexual encounters in which condoms were used correlated significantly with the number of partners for women (r = 0.37, p less than 0.01), but not for men (r = 0.03, ns). Use of intravenous drugs in the prior year, sharing of needles, use of stimulants, exchange of sex for money or drugs, and combining sexual events with drug use were all associated with greater numbers of sexual partners. A subset of male IVDUs engages in the dual-risk behaviors of needle sharing and unprotected intercourse with multiple partners. This group could act as a highly efficient vector for human immunodeficiency virus transmission and should become a focus of intensive preventive intervention.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Pineal and CNS germ cell tumors: Royal Marsden Hospital experience 1962-1987.

A retrospective analysis has been made of all patients with pineal and CNS germ cell tumors who were treated at The Royal Marsden Hospital between 1962-1987. A total of 67 new cases were seen: 17 had initial histological verification of tumor type and the remainder were tested for radiosensitivity with a dose of 20 Gy following a shunting procedure. Patients with germ cell or radiosensitive tumors were treated with a uniform policy of whole neuraxis radiotherapy giving 50 Gy to the local tumor and 30 Gy to the remaining brain and spinal cord. Nonresponding lesions continued with local fields to a dose of 50 Gy. Patients were divided into three groups (a) germinoma and radiosensitive tumours, 34 cases; (b) malignant teratoma, 12 cases; (c) non-germ cell, 21 cases. Median follow-up is 83 months (range 2-246 months). Overall and cause specific actuarial 5/10 year survival were for group 1, 81.7%/69.4% and 86.5%;/86.5%; group 2, 18.2%/18.2% and 18.2%/18.2%, and group 3, 64.3%/46.8% and 64.3%/52.6%, respectively. No patient in group 1 treated during the last 12 years has recurred. Univariate analysis of factors at presentation, showed that neurological performance status (p less than .001) as well as tumor type (p less than .001) correlated with outcome. Recurrence was confined to the primary site in only 1 of 4 patients in group 1 compared to 6 of 9 patients in group 2 and 9 of 10 patients in group 3. No isolated spinal recurrence occurred in group 1 patients. A total of eight patients have received platinum containing chemotherapy for recurrence (6 cases) or adjuvant therapy (4 cases). Germinomas appear to respond better than teratomas, all of which have recurred rapidly following initial partial response. Shunting and radiosensitivity testing remains the treatment of choice for tumors compatible with germinoma. Craniospinal irradiation is associated with low morbidity providing spinal growth is complete and is recommended in older patients as salvage following spinal recurrence is unsatisfactory. Aggressive combined modality approaches with surgery, radiotherapy and chemotherapy need to be investigated to improve results in CNS teratoma.

Adolescent↗
PubMed1990

Plasma exchange in refractory cutaneous vasculitis.

Eight patients with intractable cutaneous leucocytoclastic vasculitis were given a trial of plasma-exchange therapy. All but one improved, five substantially. Four have been successfully treated by intermittent plasma exchange for periods of 5-12 years. Apart from one episode of hepatitis B, possibly related to administration of fresh frozen plasma, no major adverse effects have occurred. Plasma exchange can be a valuable therapeutic option in patients with severe refractory cutaneous vasculitis.

Adult↗
PubMed1989

Valproic acid, unlike other anticonvulsants, has no effect on methadone metabolism: two cases.

Two patients who were concomitantly undergoing methadone maintenance treatment and receiving phenytoin suffered continuing opioid withdrawal symptoms as a results of phenytoin's acceleration of methadone metabolism. When anticonvulsant therapy was discontinued, these patients had seizures. One patient was switched to carbamazepine as an alternative anticonvulsant, but this treatment resulted in a similar clinical problem. When both patients received valproic acid instead, the withdrawal symptoms disappeared and their conditions stabilized.

Adult↗
PubMed1988

Pemphigoid and ulcerative colitis.

We report eight patients with ulcerative colitis who have subsequently developed pemphigoid. Four patients were investigated to determine the pattern of pemphigoid antibody staining on whole and chemically split skin and oral mucosa to distinguish between pemphigoid and epidermolysis bullosa acquisita. The findings were suggestive of pemphigoid with a predominantly epidermal pattern. Three patients were studied for the presence of antibodies against the colon (which were absent). The relationship between pemphigoid and ulcerative colitis is discussed in relation to a case-control study.

Adult↗
PubMed1988

Pharmacological modulation of cold-induced pain in cutaneous leiomyomata.

In two patients with painful cutaneous leiomyomata, induction of pain by the application of an ice cube allowed assessment of a number of topical and systemic treatments aimed at reducing or preventing the pain. In one patient the alpha-adrenoceptor blocker, phenoxybenzamine alleviated cold-induced pain. In the second patient, topical 9% hyoscine hydrobromide (an anticholinergic agent) decreased pain induced by the ice cube, but was not helpful in reducing lesional pain due to cold weather.

Adult↗
PubMed1988

Lymphomatoid granulomatosis--evidence of a clonal T-cell origin and an association with lethal midline granuloma.

Lymphomatoid granulomatosis and lethal midline granuloma are both characterized histologically by atypical pleomorphic angiocentric infiltrates. Whether these conditions are malignant lymphoproliferative disorders remains controversial. Here we report the results of studies carried out in a patient with coeliac disease, who developed recurrent self-healing subcutaneous nodules with the histological changes of lymphomatoid granulomatosis and an invasive nasal tumour with the histological features of lethal midline granuloma. The patient subsequently also developed an erythrophagocytic syndrome. Immunocytochemical labelling of both cutaneous and nasal lesions demonstrated a predominant population of T cells with a CD4-negative CD8-positive phenotype. Analysis of DNA from cutaneous tissue revealed a discrete rearrangement of the beta and gamma T-cell receptor genes. These findings suggest that lymphomatoid granulomatosis is a clonal T-cell lymphoproliferative disorder and its association with lethal midline granuloma indicates that both conditions may have a common histogenesis.

Celiac Disease↗
PubMed1987

Variations in mortality of the coloured, white and Asian population groups in the RSA, 1978-1982. Part V. Hypertensive diseases.

An analysis was undertaken of mortality from hypertensive disease in the RSA between 1978 and 1982 among whites, coloureds and Asians. The age-specific mortality rates for each group are presented and comparisons are also made between these groups based on age-standardised mortality rates. As with a similar study undertaken for the period 1969-1971, marked variations are seen between the various population groups. The rates for Asians exceeded those for coloureds substantially, and both these groups had far higher rates than whites. These results demonstrate an interesting variation when compared with mortality from ischaemic heart disease and recent prevalence studies of hypertension. The possibility that this variation is due to better control of hypertension in whites or is a result of a different ratio of risk factors in each group studied is considered.

Adult↗
PubMed1987

Variations in mortality of the coloured, white and Asian population groups in the RSA, 1978-1982. Part VI. Ischaemic heart disease.

An analysis of ischaemic heart disease (IHD) mortality for the period 1978-1982 showed markedly different rates for the Asian, white and coloured population groups in the RSA. Age-specific and age-standardised rates for Asians were in general considerably higher than those for whites, and did not show the marked decline with time observed in rates for whites. Although coloureds were seen to have considerably lower age-standardized rates than Asians or whites of the same sex, an increase in the age-standardised rates for coloured males over a 10-year period and a slight decrease among females suggested that rates for coloureds may be in the process of approaching those for the other groups. The observed decline in IHD rates among whites of both sexes suggests that preventable major risk factors may be coming under control, apparently to a greater extent in this group than among Asians or coloureds.

Age Factors↗
PubMed1987

Variations in mortality of the coloured, white and Asian population groups in the RSA, 1978-1982. Part I. All causes.

Previous reports, based largely on the 1970 census and the 8th revision of the International Classification of Diseases, (ICD-8) have suggested that marked differences in mortality exist between population groups in the RSA. In this article the ICD-9 classification of causes of death and 1980 census are used to assess whether the trends have continued through to the present time. Total mortality data in the RSA for whites, coloureds and Asians for the 5-year period 1978-1982 are presented. The 1980 national census provided the denominator population data. Annual age- and sex-specific mortality rates were higher for coloureds than for whites or Asians, the differences being most marked in childhood. There appears to have been little change in total standardised mortality rates among whites over the 5-year period, while increases have occurred among coloureds of both sexes and among Asian males. Analysis of proportional mortality stresses the relatively large proportion of deaths accounted for by external causes and infections among coloureds and by cardiovascular diseases among whites and Asians. There is an urgent need for the health services to take note of these data in order to provide for the varied needs of the population.

Adolescent↗