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Biomedical subjects

P Clarke

Publications and source records attributed to P Clarke.

At least 91 records · Page 5Linked to original sources
PubMed1997

Invasive Haemophilus influenzae in the Republic of Ireland.

Prior to the general availability of Haemophilus influenzae type b vaccine in the Republic of Ireland, a two-year study of the epidemiology of invasive Haemophilus influenzae disease was carried out. Of 137 invasive strains of Haemophilus influenzae examined in a central laboratory, 94.2% were serotype b and 90.5% were biotype I. Seventeen percent of serotype b strains produced beta-lactamase, and 2.3% were resistant to both ampicillin and chloramphenicol. The majority of serotype b strains were electrophoretic types of the electrophoretic 12 clone family, principally 12.5. Meningitis was the most common infection caused by serotype b. The study data extend the current knowledge of strains of Haemophilus influenzae causing invasive disease in the Republic of Ireland.

Anti-Bacterial Agents↗
PubMed1997

Delayed presentation to clinics for sexually transmitted diseases by symptomatic patients. A potential contributor to continuing STD morbidity.

OBJECTIVE: To determine the proportion of symptomatic patients attending public sexually transmitted disease (STD) clinics who fail to seek care within 7 days of the onset of STD symptoms and their self-reported reasons for delays in obtaining care. DESIGN: Interviewers administered 23-item questionnaire to a cross section of STD clinic clients between April and September 1995. SETTING: Five urban STD clinics in the United States (Birmingham, AL; St Paul, MN; San Francisco CA; Seattle, WA; and Raleigh, NC). RESULTS: Of 1,621 patients with genitourinary symptoms, over one third (35% of men, 37% of women) presented to STD clinics only after 1 week or more of symptoms. Men with genital warts (73%) or with nongonococcal urethritis (23.1%) or symptomatic men who were recent contacts to sex partners with STDs were significantly more likely to delay clinic attendance more than a week than men with gonorrhea (6.5%, p < 0.001 for each). Overall 43.8% of women receiving specific clinical diagnoses other than genital warts delayed clinic attendance for more than 1 week. When asked why they delayed clinic attendance, respondents were most likely to respond that they had hoped their symptoms would "go away" (48.5% of men and 49.4% of women who waited a week or more before seeking care). CONCLUSION: A substantial proportion of patients with genitourinary symptoms attending public STD clinics delay seeking care for a week or more, increasing their likelihood of complications and of transmission of infection to others. Interventions to promote more timely clinic attendance may help reduce STD morbidity in the United States.

Adolescent↗
PubMed1997

Patients attending STD clinics in an evolving health care environment. Demographics, insurance coverage, preferences for STD services, and STD morbidity.

OBJECTIVES: To characterize client demographics, sexually transmitted diseases (STD) morbidity, insurance status, reasons for attending public STD clinics, and future preferences for source of STD services. DESIGN: Cross-sectional study of 2,490 clients attending five urban STD clinics for new problems with interviewer-administered 23-item questionnaire and chart review to obtain clinical and laboratory STD diagnoses. RESULTS: Participants were young (51% < 25 years of age), minority (64% nonwhite), poor (43% < or = $10,000/year), and largely uninsured (59% uninsured, 27% private insurance, and 14% Medicaid). Half had previously visited the STD clinic, and 81% had used other providers for non-STD services in the prior 3 years. STD symptoms were cited as the reason for the visit by 63%. The most common factors associated with seeking care at these STD clinics were walk-in services, costs, and confidentiality concerns. STD morbidity was high; 66% of clients were diagnosed with one or more STD. Most (68%) clients preferred to be treated at the STD clinic in the future if they could go anywhere for STD services. CONCLUSIONS: STD clinics see young, minority, poor, and uninsured clients with high STD rates. Even with unlimited future choice, two thirds of the clients surveyed would still prefer to be treated at STD clinics. This study indicates the continuing need for publicly funded, categorical STD clinics in urban areas with high STD morbidity and the importance of easily accessible, confidential, expert STD services from the private sector and managed care organizations.

Adult↗
PubMed1997

The effect of cricoid pressure and neck support on the view at laryngoscopy.

Fifty female patients were studied to compare the view of the larynx at direct laryngoscopy under general anaesthesia with and without cricoid pressure applied. We also compared the view using the standard technique of cricoid pressure with that using cricoid pressure in an upward and backward direction and further investigated whether these views were improved with a firm foam rubber neck support. The order in which the types of cricoid pressure were applied was randomised and also blinded with a drape over the neck. Cricoid pressure was simulated on weighing scales after each case and a mean force of 3.2 kg was applied. The majority of views at laryngoscopy (95%) were grade 1, with too few grade 2 and 3 views for statistical comparison. Both types of cricoid pressure applied without neck support were more likely to give a better view than no cricoid pressure (p < 0.01) and cricoid pressure in an upward and backward direction was more likely to give a better view at laryngoscopy than the standard technique (p < 0.01). Neck support during the standard technique of cricoid pressure did not improve the view of the larynx at laryngoscopy. Cricoid pressure is likely to improve the view at laryngoscopy which may be further improved by applying it in an upward and backward direction.

Adolescent↗
PubMed1997

Randomized trial of the addition of flexible sigmoidoscopy to faecal occult blood testing for colorectal neoplasia population screening.

BACKGROUND: Published data suggest that screening might reduce the mortality rate from colorectal neoplasia. Faecal occult blood (FOB) testing suffers from poor sensitivity and significant numbers of interval cancers, both of which should be improved by the addition of flexible sigmoidoscopy (FOS). METHODS: This prospective, randomized study aimed to assess the compliance and neoplasia yield of FOB testing and FOS compared with that of FOB testing alone. From general practitioner registers, 6371 asymptomatic patients (3124 men, 3247 women; age range 50-74 years) were invited for screening by means of FOB testing (3128 patients) performed at home, or a combination of FOB testing and FOS (3243 patients). RESULTS: Compliance with FOB testing alone was 50 per cent. In the FOB testing/FOS group, 48 per cent returned the FOB test but only 20 per cent went on to FOS. Despite the poor compliance, the neoplasia yield was four times greater in the FOB testing/FOS group. CONCLUSION: FOS increase the neoplasia yield but strategies to improve compliance must be identified for this to become a population screening test.

Aged↗
PubMed1996

Apoptosis: does stress kill?

A wide variety of cellular stresses can initiate apoptosis, or programmed cell death. Recent work shows that the mechanism involves stress-activated protein kinase pathways, although the targets of these pathways are unknown at present.

Apoptosis↗
PubMed1996

Prognostic significance of BCL-2 expression and bcl-2 major breakpoint region rearrangement in diffuse large cell non-Hodgkin's lymphoma: a British National Lymphoma Investigation Study.

The Bcl-2 protein is capable of preventing apoptosis, and in vitro evidence suggests a role in drug resistance. It is expressed and the gene is rearranged in a proportion of cases of large-cell non-Hodgkin's lymphoma (NHL), but the clinical significance of these findings is controversial. The purpose of this study was to determine the influence of both Bcl-2 expression and major breakpoint region (MBR) bcl-2 rearrangement in a large cohort of prospectively accrued patients with intermediate-grade B-cell NHL treated in a standardized manner. All patients with Working Formulation F, G, or H NHL treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy in British National Lymphoma investigation studies between July 1974 and April 1992 were considered for this study if the appropriate paraffin blocks were available. Paraffin sections from the diagnostic specimen were analyzed for evidence of MBR rearrangement using a polymerase chain reaction-based method, and for Bcl-2 expression using immunohistochemistry. Failure to achieve complete remission (CR), relapse, death from NHL, and deaths from all causes were used as end points to measure CR rate, actuarial relapse rate, actuarial survival from NHL, and actuarial overall survival. One hundred sixty-one suitable patients were identified and tested for the bcl-2 MBR translocation, with 27 (17%) found to be positive; 153 of these patients were tested with immunocytochemistry, and 84 (55%) showed evidence of Bcl-2 expression. For patients who achieved CR from the initial treatment, the relapse rate was significantly higher in those with Bcl-2 expression than in those without. In addition, multivariate analysis identified Bcl-2 expression as the only factor significantly related to relapse rate in the subjects measured. The cause-specific survival for NHL in the series as a whole was significantly lower in patients with Bcl-2 expression than in those without. MBR status had no significant influence on any of the outcome measures, but the number of MBR-positive patients was relatively small, and larger studies are required. In conclusion, in Working Formulation F, G, and H NHL of B-cell type, expression of Bcl-2 protein predicted independently for relapse.

Adult↗
PubMed1996

Identification of a promoter that controls aromatase expression in human breast cancer and adipose stromal cells.

Aromatase, a cytochrome P450, catalyzes three consecutive hydroxylation reactions converting C19 androgens to aromatic C18 estrogens. In this study, the regulatory properties of a 696-base pair region, that contains the promoter II and is situated immediately upstream of exon II of the human aromatase gene, were investigated. Chloramphenicol acetyltransferase (CAT) functional studies with DNA segments derived from this genomic region and primer-extension analysis revealed the presence of a second promoter which is functional in adipose stromal cells and in breast cancer cells. Detailed DNase-1 footprinting analysis, DNA mobility shift assays, and CAT functional studies of this genomic region were performed and led to the identification of a segment (B1) that could act as a promoter (probably promoter I.3) in adipose stromal and breast cancer cells. The study revealed further that the B1 region could be divided into two domains which were designated RE1 and RE2. RE1 was found to have the promoter activity, and RE2 was found to regulate the promoter activity of RE1, but in different manners in MCF-7 cells (as an example of breast cancer cells) and in adipose stromal cells. RE2 was found to function as a positive regulatory element in MCF-7 cells and as a negative regulatory element in adipose stromal cells, respectively. DNA mobility shift and UV-cross-linking experiments with BrUrd-substituted B1 fragment and nuclear extracts isolated from two types of cells were performed. The experiments identified DNA-bound proteins with molecular masses around 50 kDa. These findings serve as the basis for further examination of the regulatory mechanism of aromatase expression in human breast cancer and adipose stromal cells.

Adenocarcinoma↗
PubMed1996

Gut barrier failure in experimental obstructive jaundice.

Bacterial translocation from the gastrointestinal tract is central to current concepts of endogenous sepsis. Studies were designed to evaluate the potential relevance of translocation to the high incidence of infection in obstructive jaundice. Sprague-Dawley rats underwent laparotomy and division of the bile duct or sham ligation. In Study 1, rats were sacrificed after 24 hr, 1 week, and 3 weeks and the mesenteric lymph node complex, cecum, and blood were cultured and plasma endotoxin was measured. In Studies 2 and 3, sham-and bile duct-ligated rats were challenged after 1 week with operative trauma and intravenous endotoxin, respectively. Animals were sacrificed after a further 24 hr. No translocation was observed in sham-operated rats. Although colonization of the mesenteric lymph nodes was not seen in bile duct-ligated rats after 24 hr, this was evident in 75% of rats after 1 and 3 weeks. Surgical trauma and endotoxin produced bacterial translocation in 33 and 40%, respectively, of sham-operated animals; this was enhanced in bile duct-ligated rats to 75% (P < 0.01 vs shams) and 93% (P < 0.001 vs shams), respectively. Endotoxin resulted in positive blood cultures in 71% of jaundiced rats compared with none of the sham group injected with endotoxin (P < 0.001). Biliary obstruction produces bacterial translocation and this process is enhanced by surgical trauma and endotoxin. The data support the thesis of gut barrier failure in jaundice and suggest that therapies targeted toward decreasing bacterial translocation may merit evaluation in the prophylaxis and treatment of infection in the jaundiced patient.

Animals↗
PubMed1996

A simian varicella virus (SVV) homolog to varicella-zoster virus gene 21 is expressed in monkey ganglia latently infected with SVV.

We have sequenced a simian varicella virus (SVV) open reading frame (ORF), 3,123 bp in length, whose product has 51% amino acid homology with the sequence encoded by the ORF of varicella-zoster virus gene 21. Several regions are highly conserved between the two ORFs, with homologies of approximately 80%. The SVV gene is transcribed in tissue culture cells productively infected with SVV and in monkey ganglia latently infected with SVV.

Amino Acid Sequence↗
PubMed1996

Screening for melanoma by primary health care physicians: a cost-effectiveness analysis.

BACKGROUND AND DESIGN - Australia has the highest rates of skin cancer in the world, and the incidence is estimated to be doubling every 10 years. Despite advances in the early detection and treatment of melanoma about 800 people still die nationally of the disease each year. A possible strategy for further reducing the mortality from melanoma is an organised programme of population screening for unsuspected lesions in asymptomatic people. Arguments against introducing melanoma screening have been based on cost and the lack of reliable data on the efficacy of any screening tests. To date, however, there has been no systematic economic assessment of the cost effectiveness of melanoma screening. The purpose of this research was to determine whether screening may be potentially cost effective and, therefore, warrants further investigation. A computer was used to simulate the effects of a hypothetical melanoma screening programme that was in operation for 20 years, using cohorts of Australians aged 50 at the start of the programme. Based on this simulation, cost-effectiveness estimates of melanoma screening were calculated. RESULTS - Under the standard assumptions used in the model, and setting the sensitivity of the screening test (visual inspection of the skin) at 60%, cost effectiveness ranged from Aust$6853 per life year saved for men if screening was undertaken five yearly to $12 137 if screening was two yearly. For women, it ranged from $11 102 for five yearly screening to $20 877 for two yearly screening. CONCLUSION - The analysis suggests that a melanoma screening programme could be cost effective, particularly if five yearly screening is implemented by family practitioners for men over the age of 50.

Age Distribution↗
PubMed1996

A national survey of nurse practitioner chlamydia knowledge and treatment practices of female patients.

Chlamydia is the most prevalent sexually transmitted disease in the United States, with over 4 million new infections presenting each year. The disease presents disproportionate problems for women who are generally asymptomatic; chlamydia is more difficult to diagnose in women than men. Untreated infections in women evolve into serious reproductive tract sequelae, including pelvic inflammatory disease, chronic pain, infertility, ectopic pregnancy, and neonatal complications. The bright side to this epidemic is that these sequelae are preventable. Chlamydia is both treatable and easily cured when it is detected. A national mailed survey of NPs was conducted to ascertain current chlamydia knowledge levels and clinical practices with female patients. Survey findings indicate that NPs are fairly knowledgeable about the infection and NP clinical practices are generally consistent with Centers for Disease Control and Prevention recommendations for chlamydia diagnostics and treatment. However, the survey identified NP deficits in screening and treatment practices for pregnant women. These findings are disturbing given the serious risks associated with failure to promptly diagnose and treat prenatal infections. The survey highlights the need for continuing professional education about chlamydia and other sexually transmitted infections.

Adolescent↗