Infection control and the Internet

The Internet can be enormously valuable for infection control workers. It provides access to policy documents and discussion groups debating everyday problems, and is a comprehensive source of information on infection-related topics. Here we discuss some of the more useful Internet connections.

All-trans retinoic acid and interferon-alpha-2a in patients with metastatic or recurrent carcinoma of the uterine cervix: clinical and pharmacokinetic studies. New York Gynecologic Oncology Group

BACKGROUND

Recent clinical trials with a combination of interferon (IFN alpha) and 13 cis-retinoic acid resulted in high response rates among women with locally advanced and metastatic carcinoma of the uterine cervix. The authors sought to amplify these observations by employing the isomer of 13 cis-retinoic acid, all-trans retinoic acid (tRA), in combination with IFN alpha.

METHODS

Sequential clinical trials were initiated by the New York Gynecologic Oncology Group to test the combination of tRA and IFN alpha in women with metastatic or recurrent carcinoma of the cervix who had failed primary therapy. IFN alpha was administered at 6 MU subcutaneously 3 times per week. In the first trial, tRA was administered at 50 mg/m2 orally 3 times per day on a daily schedule (daily regimen), whereas in the second trial, tRA was administered at the same dose 3 times per day, but only on Days 1-3 each week (intermittent schedule). Clinical outcomes included response to therapy and survival. Plasma pharmacokinetic studies of tRA were performed in both trials to assess the effects of different schedules on plasma levels of the drug.

RESULTS

Fourteen women with metastatic or recurrent squamous cell carcinoma of the cervix were enrolled in the daily trial and 12 women in the intermittent trial. There was no clinical activity for either regimen, and both studies were terminated according to an early stopping rule. Because tRA has been reported to induce its own metabolism, plasma levels of tRA were measured on Days 1, 8, and 28. The change in the area under the time versus tRA concentration curve (AUC) was significantly different between the two groups. The average AUC on Day 8 was 14% of that observed on Day 1 for the daily treatment group; in contrast, it was 107% on Day 1 in the intermittent treatment group. In 6 of 8 patients studied in the daily trial, the AUC decreased at least 60% by either Week 2 or Week 4. In contrast, in the intermittent trial, only 3 of 9 patients experienced >60% decrease in plasma levels of the drug at either Day 8 or Day 28.

CONCLUSIONS

The combination of tRA + IFN alpha was inactive in patients with advanced carcinoma of the cervix when employed at these doses on either the daily or intermittent schedule. The failure of activity of this regimen did not result from induction of metabolism of tRA, suggesting that intrinsic mechanisms of resistance to tRA at the cellular level may be of greater importance.

Carers of the elderly--knowledge, use of and satisfaction with day care services

This is a descriptive study of carers of dependent elderly in inner city Dublin, outlining their awareness, use of and satisfaction with day services. A striking finding from this work, consistent with other studies, is the heavy burden of care which is shouldered by informal carers which should be acknowledged by society. The study highlights a) that levels of use of domiciliary care by carers appear to be very low, b) that there is some evidence of targeting of domiciliary services to the more dependent elderly, c) that day centres and clubs are popular and acceptable to a minority of carers, d) that many carers have no informal help, e) where informal help is available, relatives of carers play a very important role in facilitating carers to accept formal domiciliary care. Recommendations include, a) improving the level and range of provision of domiciliary care, b) alerting professionals such as general practitioners and public health nurses to their role as informant and facilitator of formal care to carers, c) formulating a plan to encourage uptake of domiciliary services by carers, d) review of care provided in day centres.

Potent 2'-amino-, and 2'-fluoro-2'-deoxyribonucleotide RNA inhibitors of keratinocyte growth factor

Reiterative in vitro selection-amplification from random oligonucleotide libraries allows the identification of molecules with specific functions such as binding to specific proteins. The therapeutic usefulness of such molecules depends on their high affinity and nuclease resistance. Libraries of RNA molecules containing 2'amino-(2'NH2)- or 2'fluoro-(2'F)-2'-deoxypyrimidines could yield ligands with similar nuclease resistance but not necessarily with similar affinities. This is because the intramolecular helices containing 2'NH2 have lower melting temperatures (Tm) compared with helices containing 2'F, giving them thermodynamically less stable structures and possibly weaker affinities. We tested these ideas by isolating high-affinity ligands to human keratinocyte growth factor from libraries containing modified RNA molecules with either 2'NH2 or 2'F pyrimidines. We demonstrated that 2'F RNA ligands have affinities (Kd approximately 0.3-3 pM) and bioactivities (Ki approximately 34 pM) superior to 2'NH2 ligands (Kd approximately 400 pM and Ki approximately 10 nM). In addition, 2'F ligands have extreme thermo-stabilities (Tm approximately 78 degrees C in low salt, and specificities).

DNA aptamers block L-selectin function in vivo. Inhibition of human lymphocyte trafficking in SCID mice

Selectins participate in the initial events leading to leukocyte extravasation from the blood into tissues. Thus the selectins have generated much interest as targets for antiinflammatory agents. Therapeutic molecules based on the monomeric carbohydrate ligand sialyl Lewis X (SLe(X)) have low affinities and are not specific for a given selectin. Using SELEX (Systematic Evolution of Ligands by EXponential Enrichment) technology, we have generated aptamers specific for L-selectin that require divalent cations for binding and have low nanomolar affinity. In vitro, the deoxyoligonucleotides inhibit L-selectin binding to immobilized SLe(X) in static assays and inhibit L-selectin-mediated rolling of human lymphocytes and neutrophils on cytokine-activated endothelial cells in flow-based assays. These aptamers also block L-selectin-dependent lymphocyte trafficking in vivo, indicating their potential utility as therapeutics.

Why don't all general practices offer structured diabetes care? A comparison of practices that do not with those that do

The aim of the study was to examine whether the minority of practices not qualifying for payment for structured diabetes care programmes differ systematically from those that do. Information was collected for all Leicestershire general practices on practice size, population structure, deprivation indices, diabetes related admissions over two years and number of insulin treated patients on the district register. The 21 practices not offering structured diabetes care had a median list size of 3204, compared to 6340 for the other 124 practices (P < 0.001). Jarman and Townsend scores were higher for these practices and estimated prevalence of diabetes was 29% higher (95% CI: 26-32%). Crude admission rates were significantly higher in those practices not offering structured care. However rates adjusted for diabetes prevalence were similar (39.3 vs 39.2 per 100 insulin treated diabetics per year, P = 0.9). These results suggest that some practices face specific problems related both to small practice size and higher prevalence. If these issues are not addressed, inequalities in access to diabetes care between practice populations will persist. There is no evidence that the provision of structured care is associated with lower admission rates in this district. However more information, particularly in relation to prevalence of diabetes, is needed in order to accurately quantify this relationship. Variations in prevalence between practices should be adjusted for in any comparison of admission rates or spurious conclusions may be drawn.

Multifocal remitting-relapsing cerebral demyelination twenty years following allogeneic bone marrow transplantation

We report a case study of a female who received an allogeneic bone marrow transplantation (BMT) from a sex-mismatched related donor and who, after a twenty-year interval, developed an acute fulminant biopsy-proven demyelinating disorder of cerebral white matter which followed a remitting-relapsing chronic course. In situ hybridization studies using Y-chromosome-specific markers revealed Y-chromosome-positive mononuclear cells in biopsy samples of white matter. Magnetic resonance imaging (MRI) studies of the asymptomatic healthy male donor showed multiple white matter lesions. These observations suggest that donor lymphocytes were sensitized to central nervous system (CNS) antigens prior to or at the time of transplantation but remained dormant for 20 years before becoming activated to cause widespread demyelination.

Calcium-dependent oligonucleotide antagonists specific for L-selectin

The selectins are calcium-dependent C-type lectins that recognize complex anionic carbohydrate ligands, initiating many cell-cell interactions in the vascular system. Selectin blockade shows therapeutic promise in a variety of inflammatory and postischemic pathologies. However, the available oligosaccharide ligand mimetics have low affinities and show cross-reaction among the three selectins, precluding efficient and specific blockade. The SELEX (systematic evolution of ligands by exponential enrichment) process uses combinatorial chemistry and in vitro selection to yield high affinity oligonucleotides with unexpected binding specificities. Nuclease-stabilized randomized oligonucleotides subjected to SELEX against recombinant L-selectin yielded calcium-dependent antagonists with approximately 10(5) higher affinity than the conventional oligosaccharide ligand sialyl LewisX. Most of the isolated ligands shared a common consensus sequence. Unlike sialyl LewisX, these antagonists show little binding to E- or P-selectin. Moreover, they show calcium-dependent binding to native L-selectin on peripheral blood lymphocytes and block L-selectin-dependent interactions with the natural ligands on high endothelial venules.

Transitional cell carcinoma of the renal pelvis or ureter: patterns of failure

OBJECTIVES

To identify recurrence patterns and possible indications for adjuvant treatment.

METHODS

Ninety-four patients with transitional cell carcinoma of the renal pelvis or ureter were reviewed to determine their pattern of failure. Factors including gender and age, tumor stage and grade, and extent of surgical procedure and adjuvant radiation therapy (RT) were analyzed with respect to local and distant recurrence and survival.

RESULTS

Seventy-seven patients had resections without residual. On multivariate analysis, grade (P = 0.01) and adjuvant RT (P = 0.02) had significant effects on local control. Metastases were solely dependent on stage (P = 0.0001). Survival was dependent on stage (P = 0.0059) and age (P = 0.036), with the use of adjuvant RT of borderline significance (P = 0.07). Twenty-seven patients were excluded from local failure and survival analysis; of these, 3 died within 1 month of surgery, 5 had metastasis at presentation, and 19 had local disease that was unresectable. Eleven of these 19 were treated by RT, resulting in 2 long-term disease-free survivors after receiving doses of 45 and 50.4 Gy.

CONCLUSIONS

In patients with adverse factors, such as high grade or stage, close margins, or positive nodes, local control can be improved with adjuvant radiation. Improvement in survival is of borderline significance on multivariate analysis, with approximately 50% of high stage or grade patients developing metastasis.

Isolation and sequence of the t-RNA ligase-encoding gene of Candida albicans

The gene encoding tRNA ligase from Candida albicans was isolated from a genomic library by complementation of a Saccharomyces cerevisiae strain containing a disrupted structural gene, RLG1, encoding tRNA ligase. The cloned gene also complements a temperature-sensitive allele of RLG1. Sequence analysis revealed a single 2499-nt coding region. The gene encodes a protein of 833 amino acids that is 42% identical to S. cerevisiae tRNA ligase. Hybridization to chromosomes of C. albicans separated by pulsed-field gel electrophoresis located the gene to chromosome 1, the smallest C. albicans chromosome.

The epidemiology of rubella in the Republic of Ireland

The trend in notified cases of rubella in the Republic of Ireland from 1950 to 1990 has been downward, with a mean interval of four years between peak periods. Vaccine uptake and antenatal immunity levelled out in the 1980s at 85% and 87%, respectively. One hundred and six cases of congenital rubella were recorded between 1975 and 1990, 66 being reported by paediatricians. The fact that cases of congenital rubella still occur highlights the need for a continued and aggressive immunisation policy, up-to-date and cohort-based data on vaccine uptake, and the introduction of a congenital rubella register.

Overexpression of Her-2/neu may be an indicator of poor prognosis in prostate cancer

Previous reports have shown that Her-2/neu oncogene expression in human breast cancer and ovarian cancer may be associated with poorer prognosis. We report the expression of Her-2/neu on fresh samples of known prostatic adenocarcinoma but not on those of benign prostatic hypertrophy. Using a monoclonal antibody (TA1) directed against human Her-2/neu oncogene product and an immunohistochemical staining method, no Her-2/neu expression was noted with benign prostatic hypertrophy (15 samples). With prostatic adenocarcinoma samples, a subset (9 of 25) showed overexpression of Her-2/neu. Such overexpression is correlated with higher histological grade, higher stage of disease, and high S phase and aneuploidy on flow cytometric analysis. These findings suggest that Her-2/neu may be a prognostic marker in prostate cancer as well.

Trial of antihypertensive intervention and management: greater efficacy with weight reduction than with a sodium-potassium intervention

The Trial of Antihypertensive Intervention and Management evaluated nine diet-drug combinations in 878 mildly hypertensive, moderately obese participants using a 3 x 3 factorial design. Drugs evaluated were placebo, diuretic (chlorthalidone), and beta-blocker (atenolol); diets were usual (no intervention), weight reduction, and low sodium/high potassium (Na/K). This article reports 6-month dietary changes and the effect of dietary change on blood pressure. Six-month mean weight change was -4.7 kg in the weight reduction group, -0.3 kg in the Na/K group, and -0.5 kg in the usual-diet group. At 6 months, daily electrolyte excretion had changed in the Na/K intervention group. Daily sodium excretion decreased from 138.0 to 112.0 mmol in the Na/K group and increased from 134.1 to 138.4 mmol in the weight reduction group and from 129.1 to 137.0 mmol in the usual-diet group. Daily potassium output increased from 58.7 to 71.4 mmol in the Na/K group, from 57.0 to 60.5 mmol in the weight reduction group, and from 55.3 to 59.1 mmol in the usual diet group. Analysis of 3-day food records indicated that sodium intake decreased from 141.1 to 85.8 mmol and potassium intake increased from 76.4 to 90.5 mmol. Our results indicate that the goal for weight reduction was more easily achieved than the goal for electrolyte modification.

Species differences in 5 alpha-androstane-3 beta,17 beta-diol hydroxylation by rat, monkey, and human prostate microsomes

The 6 alpha-, 7 alpha-, and 7 beta-hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol by rat prostate microsomes appears to be catalyzed by a single, high-affinity cytochrome P450 enzyme. In the present study we have examined the hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol by prostate microsomes from cynomolgus monkeys and from normal subjects and patients with benign prostatic hyperplasia. Our results suggest that although rat, monkey, and human prostate microsomes catalyze the 6 alpha-, 7 alpha-, and 7 beta-hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol, these pathways of oxidation in monkeys and humans are not catalyzed by a single cytochrome P450 enzyme. The ratio of the three metabolites was not uniform among prostate microsomal samples from individual humans or monkeys. The 6 alpha-hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol varied independently of both the 7 alpha- and 7 beta-hydroxylation, which varied in unison. The 6 alpha-, 7 alpha-, and 7 beta-hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol by monkey prostate microsomes appeared to be differentially affected by in vivo treatment of monkeys with beta-naphthoflavone or dexamethasone. Treatment of a monkey with dexamethasone appeared to cause a 2.5-fold increase in both the 7 alpha- and the 7 beta-hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol without increasing the 6 alpha-hydroxylation. The 7 alpha- and 7 beta-hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol by human and monkey prostate microsomes, but not the 6 alpha-hydroxylation, was inhibited by antibody against rat liver NADPH-cytochrome P450 reductase. Similarly, the 7 alpha- and 7 beta-hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol by human prostate microsomes, but not the 6 alpha-hydroxylation, was markedly inhibited (greater than 85%) by equimolar concentrations of the imidazole-containing antimycotic drugs ketoconazole, clotrimazole, and miconazole. These results suggest that the 7 alpha- and 7 beta-hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol by monkey and human prostate microsomes is catalyzed by a cytochrome P450 enzyme, whereas the 6 alpha-hydroxylation is catalyzed by a different enzyme which may or may not be a cytochrome P450 monooxygenase. The hydroxylation of 5 alpha-androstane-3 beta,17 beta-diol by prostate microsomes from normal human subjects was quantitatively and qualitatively similar to its hydroxylation by prostate microsomes from patients with benign prostatic hyperplasia.(ABSTRACT TRUNCATED AT 400 WORDS)

The epidemiology of pertussis in the Republic of Ireland

Epidemiological data on pertussis in the Republic of Ireland have been gathered annually since 1941. However, no detailed analysis of these data has, until now, been carried out. Fifteen epidemics occurred between 1941 and 1989, an average of one per 3.1 years, which is similar to epidemic intervals observed elsewhere. After the introduction of a vaccine in the 1950s, annual pertussis notifications declined, from 175 per 100,000 in 1956 to 7.6 per 100,000 in 1972. Following adverse publicity in 1973, uptake of the vaccine fell to 30% in 1976. Although uptake has increased again in recent years, it has levelled out at only 40-45% and large epidemics of pertussis occurred in 1985 and 1989. At the same time, mortality from pertussis has fallen to almost negligible levels. Most cases occur in children more than one year of age. Changes in the vaccination schedule could have a major impact on the incidence of the disease in the Republic of Ireland. However, if a further decline in the incidence of the disease is to be achieved, parents have to be persuaded of the benefits of pertussis vaccination.