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Biomedical subjects

J Weir

Publications and source records attributed to J Weir.

At least 37 records · Page 2Linked to original sources
PubMed1999

Patient selection criteria in the surgical treatment of veno-occlusive dysfunction.

PURPOSE: We evaluated short and long-term results of simple and complex venous surgery in patients with veno-occlusive dysfunction unresponsive to maximum recommended doses of intracavernous alprostadil, who were selected with newly developed diagnostic indicators. MATERIALS AND METHODS: A total of 23 impotent men with a mean age of 41 years (range 20 to 50) underwent complex penile venous surgery. Only patients fulfilling at least 3 criteria were included in study. The criteria were mild cavernous leak assessed by cavernosometry (grades 1 and 2), more than 30% cavernous smooth muscle tissue (histomorphometric analysis), normal analogical corpus cavernosum electromyography recordings according to international standards, cavernosal oxygen tension greater than 65 mm. Hg at erection and age younger than 50 years. RESULTS: Of 23 patients 17 (74%) had normal erections within a year after surgery, and 5 of them (29%) complained of recurrent erectile dysfunction. At long-term followup 6 of 12 patients had spontaneous erections. CONCLUSIONS: Careful selection with advanced diagnostic techniques should be mandatory before performing venous surgery in patients with high degree veno-occlusive dysfunction as the only alternatives are major therapeutical solutions.

Adult↗
PubMed1998

Extracellular levels of dopamine and its metabolite 3,4-dihydroxy-phenylacetic acid measured by microdialysis in the corpus striatum of conscious AS/AGU mutant rats.

The AS/AGU rat is a mutant derived from the Albino Swiss (AS) strain. It is characterized by an ungainly, staggering gait, hind limb rigidity, whole body tremor and, in older animals, difficulty in initiating movement. As and AS/AGU males aged three, six and nine months (n=6 per group) were used to estimate the levels of dopamine and its metabolites in the extracellular fluid of the caudate-putamen. The results indicate a profound loss of dopamine in the extracellular fluid at all age points examined, together with an increase in the concentration of the metabolite 3,4-dihydroxyphenylacetic acid. It is suggested that these changes reflect a defect of dopaminergic neuron function which may underlie the motor disorder seen in these animals.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1998

Partial regression in primary carcinoma of the lung: does it occur?

AIMS: To study immunohistochemically a group of 28 primary lung cancers which demonstrated histological features reminiscent of those characteristic of regression in malignant melanoma, to determine the phenotype of their immune cell infiltrates. METHODS AND RESULTS: Using a standard s-ABC immunoperoxidase method then quantification by the Leica Q500 MC image analyser, the cellular infiltrate in these tumours, when compared to 67 control cases, showed excess CD3 + T lymphocytes (P < 0.007), with an increase in CD4:CD8 ratio and increased CD68 + macrophages (P = 0.00001). CD57 + natural killer cells and S100 + Langerhans cells were also increased, but not quite significantly (P = 0.048 and P = 0.072, respectively). CONCLUSIONS: This immunophenotype resembles that shown in regressing skin malignancies and suggests a similar process occurring in lung cancer. Regressing lung cancers are associated with a better prognosis than matched controls (P = 0.0034), some showed radiological evidence of growth retardation and the group had an excess of the large cell undifferentiated histological type.

Antigens, CD↗
PubMed1997

Sale of cigarettes to school children aged 14 and 15 years in New Zealand.

AIMS: To determine the sources of cigarettes and extent of illegal sales to 14 and 15 year old children, and to examine associated risk factors in order to more effectively reduce tobacco access to children. METHOD: Nationwide cross sectional survey of fourth form school children in New Zealand by means of an anonymous self administered questionnaire. RESULTS: Questionnaires from 14,097 fourteen and fifteen years olds were analysed, with over one third smokers. Twenty four percent of the whole group (3432) had bought cigarettes in the last year. Of smokers, 59.9% bought their own, with the great majority (68.9%) from dairies, particularly females. Ninety five percent said it was "easy" or "very easy" to buy cigarettes, and this was a major risk factor for this behaviour (relative risk (RR) = 2.01, 95% confidence interval (CI) 1.74, 2.32, RR = 2.54, CI 2.28, 2.83, respectively). Only 24.6% children had ever been refused cigarettes because of age and all points of sale were comparable in this respect. Heavy smokers and males were more likely to have been refused. While refusal was associated with a fourfold increase in the perception that it was difficult to buy cigarettes, there was only a minimal reduction in the risk of children buying their own cigarettes (RR = 0.95, CI 0.91, 1.00). CONCLUSION: We have shown that the illegal sale of cigarettes to children is unacceptably easy and accurately perceived as such by children who smoke. The active enforcement of existing or future legislation is essential, with prosecution of offending retailers, if we are to make any progress to reduce the high prevalence of smoking in New Zealand children.

Adolescent↗
PubMed1995

A national survey of cigarette smoking in fourth-form school children in New Zealand.

AIMS: To determine the prevalence of cigarette smoking in 14 and 15 year old school children in New Zealand and to examine associated risk factors. METHODS: Nationwide cross-sectional survey of fourth-form school children in New Zealand by means of an anonymous self administered questionnaire in November 1992. RESULTS: Questionnaires from 14,097 fourteen and fifteen year-olds were analysed. 65.6% had tried smoking, and 36.1% regarded themselves as smokers. Females and Maori had significantly higher prevalence rates. Of Maori females 44.6% were current smokers (more than one per month) compared to 24.0% for the whole group, and 33.0% were daily smokers. Pacific Island students, who have similar socioeconomic disadvantage to Maori, have a lower relative risk of smoking (RR) 0.79, (95% confidence interval (CI) 0.68, 0.91), than Europeans. Major independent risk factors were identified and population attributable risk was calculated for parental smoking (22.9%), poor knowledge of adverse health effects (7.3%) and watching televised sports (13.4%). These three modifiable factors accounted for 36.1% of the total smoking prevalence in these children. CONCLUSION: The continued high prevalence of smoking in New Zealand children, especially in Maori and in females, prove current public health measures to be inadequate. Our results suggest that strategies aimed at decreasing parental smoking, improving student knowledge of adverse health effects and preventing tobacco sponsorship of television sports could greatly decrease the smoking prevalence in this age group.

Adolescent↗
PubMed1995

Supraglottic transection: results of repair and functional outcome.

We present two cases of supraglottic transection, with concomitant neurotemesis of the superior laryngeal nerve. Both cases were repaired primarily and a temporary tracheostomy was used to protect the airway. In both cases subsequent decannulation was achieved within four weeks, following the initial injury. No long-term swallowing or voice disturbance was noted in either case. We recommend that in such cases it is unnecessary to repair the nerves directly, but that careful repair of the wound itself will achieve a functional result.

Adult↗
PubMed1995

An examination of driving records in a dementia clinic.

The driving records of 249 persons referred to an outpatient dementia clinic were examined retrospectively to assess the specificity of the association between diagnosed dementia and increased traffic accidents. The clinic patients were divided into two groups: those who met criteria for dementia and those who did not. For each group, control subjects matched on age, gender, and location of residence were randomly selected from the records of all drivers in the province. The dementia sample had approximately 2.5 times the traffic crash rate of their matched control sample. The not-demented sample had approximately 2.2 times the traffic crash rate of their matched control sample. These individuals exhibited a variety of psychiatric, neurological, and medical conditions which could have affected their driving, and multiple medical problems were often present. Further clarification of the characteristics of "high risk" drivers is required if effective strategies for maximizing independence while minimizing the risk of traffic crashes are to be realized.

Accidents, Traffic↗
PubMed1995

Novel mutations in reverse transcriptase of human immunodeficiency virus type 1 reduce susceptibility to foscarnet in laboratory and clinical isolates.

Foscarnet (phosphonoformic acid) is a pyrophosphate analog that inhibits the replication of human immunodeficiency virus type 1 (HIV-1) in vitro and in patients with AIDS. HIV-1 resistance to foscarnet has not been reported despite long-term foscarnet therapy of AIDS patients with cytomegalovirus disease. We therefore attempted to select foscarnet-resistant HIV-1 in vitro by serial endpoint passage of virus in 400 microM foscarnet. After 13 cycles of passage in MT-2 cells, virus exhibiting > or = 8.5-fold foscarnet resistance was isolated. The reverse transcriptase (RT) from resistant virions exhibited a similar level of foscarnet resistance in enzyme inhibition assays (approximately 10-fold resistance). Foscarnet-resistant virus showed increased susceptibility to 3'-azido-3'-deoxythymidine (90-fold) and to the HIV-1-specific RT inhibitors TIBO R82150 (30-fold) and nevirapine (20-fold). DNA sequence analysis of RT clones from resistant virus revealed the coexistence of two mutations in all clones: Gln-161 to Leu (CAA to CTA) and His-208 to Tyr (CAT to TAT). Sequence analysis of six clinical HIV-1 isolates showing reduced susceptibility to foscarnet revealed the Tyr-208 mutation in two, the Leu-161 mutation in one, and a Trp-88-to-Ser or -Gly mutation in four isolates. Site-specific mutagenesis and production of mutant recombinant viruses demonstrated that the Leu-161, Ser-88, and Tyr-208 mutations reduced HIV-1 susceptibility to foscarnet 10.5-, 4.3-, and 2.4-fold, respectively, in MT-2 cells. In the crystal structure of HIV-1 RT, the Gln-161 residue lies in the alpha E helix beneath the putative deoxynucleoside triphosphate (dNTP) binding site. The Gln-161-to-Leu mutation may affect the structure of the dNTP binding site and its affinity for foscarnet. The location of the Trp-88 residue in the Beta5a strand of HIV-1 RT suggest that the Ser-88 mutation affects template-primer binding, as do several mutations that affect RT susceptibility to nucleoside analogs.

Base Sequence↗
PubMed1995

Corynebacterium afermentans subsp. lipophilum: multiple abscess formation in brain and liver.

Corynebacterium afermentans, a species recently identified, has previously been isolated from human blood cultures. We report the case of a previously healthy 39-year-old man who developed a brain abscess and a liver abscess due to Corynebacterium afermentans subsp. lipophilum. The liver abscess penetrated through the diaphragm to cause pleural effusion and periostitis of the ribs. We believe this is the first reported case of disseminated infection with abscess formation due to this organism.

Adult↗
PubMed1994

Epidemiology of hepatitis C virus in western Venezuela: lack of specific antibody in Indian communities.

Hepatitis C virus (HCV) is transmitted mainly by the parenteral route after percutaneous exposure to virus-infected products or body fluids. Thus, HCV shares with hepatitis B and D (HBV, HDV) viruses this common transmission route. The prevalence of antibody against HCV (anti-HCV) was studied in 1155 serum samples from individuals at risk of infection by bloodborne or sexually transmitted agents, as well as from others lacking such risk factors, from the city of Maracaibo, Venezuela. Anti-HCV and serological markers of infection by HBV and HDV were also studied in further 550 samples taken from Bari Indians living in different communities in the Perijá mountains, State of Zulia, Venezuela. The results obtained showed that recipients of blood or blood products are at increased risk of HCV infection in Maracaibo, whereas sexual transmission plays only a minor role if any. Both HBV and HDV infections were highly prevalent among Bari Indians (64.4% positive for anti-HBc; 11.1% of HBsAg carriers; 15.3% positive for anti-HDV among HBsAg carriers). No anti-HCV positive samples were, however, detected among them, thus suggesting either that HCV has not still reached this population or that HBV and HDV are transmitted by routes unshared by HCV. Anti-HCV was also absent among samples from mentally retarded patients from Maracaibo, thus confirming similar findings from other countries and supporting the existence of specific transmission mechanisms for HBV and HDV which are not working for HCV.

Antibody Specificity↗
PubMed1994

The association of tracheomegaly and bronchiectasis.

This study set out to determine the frequency of tracheomegaly in brochiectasis as judged by high resolution computed tomography (HRCT) while determining whether the published normal tracheal dimensions derived from radiographic data can be used for CT diagnosis. Seventy-five consecutive adults referred for CT assessment of possible bronchiectasis were studied and compared with a control group of 75 adults being staged for lymphoma. The internal tracheal diameters at aortic arch level of the control group correspond with published radiographic data and using these measurements, 7/42 (17%) patients with bronchiectasis were found to have tracheomegaly, while two of the 33 'symptomatic' patients (i.e. those patients not found to have bronchiectasis) had tracheomegaly. Further analysis confirmed that the bronchiectatic group's tracheal dimensions were significantly different from those of the control group while the 'symptomatic' group are an overlap population. We conclude that tracheomegaly is a frequent finding in bronchiectasis.

Adolescent↗
PubMed1993

Computed tomography of the chest in T1NoMo non-small cell bronchial carcinoma.

There has been controversy within the recent literature as to the value of computed tomography (CT) of the chest in patients with T1NoMo non-small cell bronchial carcinoma, as staged by plain radiography and bronchoscopy. This paper reports on 63 such patients, nine (14.2%) of whom were shown correctly by CT of the chest to have metastatic spread which rendered them inoperable. Of these nine, four had stage N3 mediastinal disease; the other five had metastatic disease, either pulmonary or bony. Patients with lesions less than 2 cm in diameter were also looked at separately: 4/20 had inoperable disease on CT of the chest. In both groups the detection rate of inoperability by CT of the chest justifies its use pre-operatively in all T1NoMo non-small cell bronchial carcinomas, in terms of clinical morbidity, mortality and cost.

Adult↗
PubMed1992

[CD10(CALLA)-negative acute lymphoblastic leukemia. A group with a bad prognosis].

The results of 188 patients with acute lymphoblastic leukemia, studied between 1985 and 1990, showed that 8 cases were CD10 negative, Dr, and CD19 positive. These findings indicate cell dedifferentiation and poor prognosis. The patients age ranged from 2 to 30 years, with a mean of 11 years. The male/female ratio was 5/3. Lymph node enlargement and splenomegaly were found in the 8 patients. With the exception of one patient in whom leucopenia was present, the white cell counts were always higher than 30,000/dl. The karyotype was studied in four cases, and all of them were hyperdiploid. This is the first report in Venezuela of cases with acute lymphoblastic leukemia - CD 10 negative.

Adolescent↗
PubMed1991

Cued recall and early identification of dementia.

The early detection of dementia carries implications for clinical management for patients and their families and is of utmost concern if an effective pharmacological treatment is to be found. The utility of an enhanced cued recall paradigm for predicting dementia in a group of elderly subjects was examined. Forty-five subjects referred for clinical evaluation who did not meet the criteria for dementia at initial assessment were reassessed 12-18 months later. Eighteen of these subjects were diagnosed as having possible or probable Alzheimer Disease at reassessment and the diagnostic status of 27 remained unchanged. At initial assessment the 'change' group performed more poorly than the 'no change' group on measures of retrieval, acquisition and retention derived from the cued recall procedure. As would be expected, the performance of the 'no change' group remained stable over time whereas the performance of the 'change' group deteriorated, resembling the performance of a group of subjects with mild possible or probable Alzheimer disease. When the sensitivity and specificity of the memory variables were examined, the retrieval measure (i.e., free recall) appeared most useful as an early predictor of dementia. Continued longitudinal evaluations of subjects with questionable dementia are needed to address more fully the natural history of early memory changes associated with dementia.

Aged↗
PubMed1991

Post-transcriptional control of a sporulation regulatory gene encoding transcription factor sigma H in Bacillus subtilis.

The transcriptional regulatory gene spoOH encodes an RNA polymerase sigma factor called sigma H that directs gene expression at an early stage of sporulation in the Gram-positive bacterium Bacillus subtilis. We now report that conditions that induce sporulation cause a rapid increase in the cellular concentration of sigma H. This increase could account for the stimulated transcription of certain sigma H-controlled genes at the onset of sporulation. Experiments in which the expression of spoOH was monitored by use of a spoOH-lacZ fusion and in which expression of spoOH was artificially manipulated by use of an isopropyl-beta-D-thiogalacto-side-inducible promoter indicate that sporulation-induced increases in the amount of sigma H are not controlled at the level of the transcription of its structural gene. Rather, we infer the existence of post-transcriptional control mechanisms that govern sigma H levels, and we present evidence suggesting that increases in the amount of sigma H at the start of sporulation are due to increased translation or stability of the spoOH mRNA and, to a lesser extent, decreased turnover of spoOH protein.

Adenosine↗
PubMed1991

Regulation of spo0H, a gene coding for the Bacillus subtilis sigma H factor.

The Bacillus spo0H gene codes for sigma H, which, as part of the RNA polymerase holoenzyme E sigma H, is responsible for the transcription of several genes which are expressed at the beginning of the sporulation process. In this communication, we examined the regulation of the spo0H gene of Bacillus subtilis by using lacZ reporter gene assays, quantitative RNA determinations, and Western immunoassay. The expression of the spo0H gene increases as the culture enters the mid-logarithmic stage of growth. This increased expression requires the genes spo0A, spo0B, spo0E, and spo0F, and the requirement for at least spo0A and spo0B can be bypassed when the abrB gene is mutated. The expression of the spo0H gene is constitutive in the presence of the abrB mutation, being expressed at higher levels during vegetative growth. In addition, the sof-1 mutation, in the spo0A structural gene, can bypass the need for spo0F in spo0H expression. The transcriptional start site of spo0H was determined by using RNA made in vivo as well as in vitro. These studies indicate that spo0H is transcribed by the major vegetative RNA polymerase, E sigma A. spo0H RNA and sigma H levels during growth are not identical to each other or to the pattern of expression of spoVG, a gene transcribed by E sigma H. This suggests that spo0H is regulated posttranscriptionally and also that factors in addition to sigma H levels are involved in the expression of genes of the E sigma H regulon.

Bacillus subtilis↗