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Biomedical subjects

A Talbot

Publications and source records attributed to A Talbot.

At least 19 recordsLinked to original sources
PubMed2002

Audit of acute myocardial infarctions at Saint James's Hospital, Dublin, from 1996 to 1999.

Saint James' Hospital is a 650-bed tertiary referral hospital. An audit was performed of acute transmural myocardial infarctions for the years 1996 to 1999 inclusive. On average there were 2043 cardiology admissions annually, 9.8% of all hospital admissions. Acute transmural myocardial infarction was diagnosed in 178 patients annually, and was less common during the summer. The figure of 72% receiving revascularisation therapy (thrombolysis 67%, primary angioplasty 5%) compares favourably with 35% in 1992. The main reason for not receiving thrombolysis was late presentation (15%) with contraindications present in only 5%. The case fatality rate was 16% confirming the higher mortality in clinical practice than that of thrombolytic trials. The prescription of aspirin or warfarin (99%) and betablockers (67%) was in line with international trials. The use of angiotensin converting enzyme inhibitors (34%) and statins (28%) is similar to other studies but less than would be expected according to trial evidence.

Adrenergic beta-Antagonists↗
PubMed2000

Cushing's syndrome due to phaeochromocytoma secreting the precursors of adrenocorticotropin.

Adrenal phaeochromocytoma rarely causes ectopic ACTH syndrome. We describe a 44-yr-old hypertensive woman who was Cushingoid and markedly pigmented. Laboratory studies indicated severe hypokalaemia, abnormal liver function tests, and random serum cortisols greater than 1660 nmol/L. Urinary catecholamines were markedly increased. An abdominal computed tomography scan showed a 4-cm left adrenal mass and an hypertrophied right adrenal. ACTH levels were elevated at 200 pmol/L, but ACTH precursors, which cross-react in the ACTH assay, were more highly elevated at 1625 pmol/L. The tumor cells cultured in vitro also secreted ACTH precursors, whereas ACTH levels were undetectable. Because the patient was highly pigmented, we measured circulating concentrations of alpha-MSH, which were undetectable and certainly insufficient to stimulate melanogenesis, suggesting that tumorderived ACTH precursors or ACTH were responsible for the pigmentation. A laparoscopic adrenalectomy resulted in remission of the Cushing's syndrome and dramatic reduction in the pigmentation. Before operation, treatment of the patient with metyrapone and replacement dexamethasone decreased cortisol from more than 1660 to less than 20 nmol/L. Surprisingly, this resulted in a decrease in ACTH precursors to 100 pmol/L and ACTH to 9.0 pmol/L. In vitro treatment of the tumor cells with dexamethasone for 24 or 40 h increased ACTH precursor secretion. In summary, this phaeochromocytoma causing Cushing's syndrome secreted primarily ACTH precursors, which seemed to cause the marked pigmentation. In vivo and in vitro evidence suggests that glucocorticoids induced ACTH precursor secretion.

Adrenal Gland Neoplasms↗
PubMed1999

Outcome of reflux therapy on pediatric chronic sinusitis.

OBJECTIVE: The cause of pediatric chronic sinusitis is multifactorial, but nasal edema appears to be the initial pathologic step. The objective of this study is to evaluate gastronasal reflux as a possible cause of pediatric sinusitis. METHODS: Thirty children with chronic sinusitis were believed to be appropriate candidates for functional endoscopic sinus surgery. Children were evaluated retrospectively for their response to reflux therapy with regard to their sinus symptoms and avoidance of sinus surgery. RESULTS: Two of the 30 children were eventually excluded because they were taken to surgery for the specific purpose of contact point release. Chart review at 24-month follow-up indicated that 25 of the 28 children (89%) avoided sinus surgery. CONCLUSION: After reflux treatment, the number of children requiring sinus surgery was dramatically reduced. The results of this preliminary pediatric study indicate that gastronasal reflux should be evaluated and treated before sinus surgical intervention.

Adolescent↗
PubMed1997

Roentgen stereophotogrammetric analysis using computer-based image-analysis.

The two-dimensional position of markers in radiographs for Roentgen Stereophotogrammetric Analysis (RSA) is usually determined using a measuring table. The purpose of this study was to evaluate the reproducibility and the accuracy of a new RSA system using digitized radiographs and image-processing algorithms to determine the marker position in the radiographs. Four double-RSA examinations of a phantom and 18 RSA examinations from six patients included in different RSA-studies of knee prostheses were used to test the reproducibility and the accuracy of the system. The radiographs were scanned at 600 dpi resolution and 256 gray levels. The center of each of the tantalum-markers in the radiographs was calculated by the computer program from the contour of the marker with the use of an edge-detection software algorithm after the marker was identified on a PC monitor. The study showed that computer-based image analysis can be used in RSA-examinations. The advantages of using image-processing software in RSA are that the marker positions are determined in an objective manner, and that there is no need for a systematic manual identification of all the markers on the radiograph before the actual measurement.

Arthrography↗
PubMed1995

Discourse comprehension and problem solving: decisions about the treatment of breast cancer by women across the life span.

The 1st study examined the decision making and prose comprehension of 94 women interacting with an authentic, unfolding health scenario about breast cancer. The 2nd study involved questionnaire data focusing on the decisions made by 75 women who had been diagnosed with breast cancer. Two major findings emerged from this laboratory and survey research. First, older women sought less information when making treatment decisions about breast cancer. However, the outcome of those decisions were equivalent to those of younger women. Second, older women made these decisions faster than younger women. In addition, treatment decisions were related to prose processing, the type of information underlined as important while reading as well as the type of information remembered about various treatment options.

Adolescent↗
PubMed1994

Vestibular schwannoma in an only hearing ear.

A vestibular schwannoma in an only hearing ear is a difficult management problem. A case is presented of a patient who had a Nucleus-22 channel device implanted into a nonfunctioning ear and auditory rehabilitation prior to resection of a large vestibular schwannoma in the contralateral ear.

Aged↗
PubMed1994

Mycobacterium tuberculosis alters expression of adhesion molecules on monocytic cells.

The host response to Mycobacterium tuberculosis is characterized by interactions between mononuclear cells, with recruitment and fusion of these cells culminating in granuloma formation. In addition, the host response to M. tuberculosis requires CD4+ T-cell reactivity, mediated by antigen-independent as well as antigen-dependent mechanisms. Thus, we hypothesized that cell adhesion molecules such as intercellular adhesion molecule 1 (ICAM-1; CD54) would participate in the response to infection with M. tuberculosis. Exposure of THP-1 cells derived from a monocyte/macrophage cell line to M. tuberculosis (1:1 bacterium/cell ratio) elicited a sustained increase (660% +/- 49% above resting level) in the expression of ICAM-1 that continued for at least 72 h. Neither the expression of vascular cell adhesion molecule 1 (VCAM-1; CD106) nor that of the integrins lymphocyte function-associated antigen 1 (LFA-1; CD11a/CD18) or CR3 (CD11b/CD18) was increased to a similar extent at corresponding time points. The increase in ICAM-1 protein expression was accompanied by an increase in steady-state mRNA (Northern [RNA] analysis). Neutralizing monoclonal antibodies directed against tumor necrosis factor alpha but not interleukin 1 alpha or interleukin 1 beta substantially abrogated the response to M. tuberculosis consistent with a paracrine or autocrine response. Continuous upregulation of the expression of ICAM-1 on mononuclear phagocytes induced by M. tuberculosis may mediate the recruitment of monocytes and enhance the antigen presentation of M. tuberculosis, thus permitting the generation and maintenance of the host response.

Cell Adhesion Molecules↗
PubMed1993

A new portable device for automatic controlled-gradient cryopreservation of blood mononuclear cells.

Protection of the functional integrity of mononuclear cells stored in liquid N2 requires careful control of the freezing procedure. Consequently, optimal quality of cryopreserved cells is usually assured by freezing according to a specified time-temperature gradient generated by computer-controlled freezing devices. While such equipment offers large capacity and secures maximum survival and functional integrity of the lymphocytes upon thawing, it is quite costly and strictly stationary. We have previously developed and tested an alternative, manual device for controlled-gradient lymphocyte freezing, which has proved suitable for field conditions. We report here the development and testing of a similar micro-controller regulated device, allowing unattended and automatic controlled-gradient cell freezing. The equipment exploits the temperature gradient present between the liquid N2 surface and the neck in an ordinary liquid N2 refrigerator. The lymphocyte samples are placed in a small elevator, which is moved through the N2 gas phase by a stepper motor. Time and temperature are measured at regular intervals, and the position of the samples adjusted to ensure that the actual measurements closely match encoded ideal values. Results of assays of the functional integrity and phenotypic composition of human mononuclear cells frozen by the new system were comparable to those obtained when using cells frozen by a commercially available, stationary cell-freezing equipment, or fresh autologous cell samples tested in parallel. Furthermore, there was a good correlation between functional and phenotypic data obtained using frozen and autologous fresh samples of mononuclear cells. The equipment described is low weight and has low N2 consumption, and is thus suitable for the collection and cryopreservation of lymphocytes under field conditions. Furthermore, the technique provides an inexpensive alternative for researchers with a limited requirement for the simultaneous freezing of large quantities of cells.

Blood Preservation↗
PubMed1989

Quantitative and qualitative changes in LH secretion following pulsatile GnRH therapy in a man with idiopathic hypogonadotrophic hypogonadism.

The pattern of bioactive and immunoreactive LH secretion before and during pulsatile GnRH therapy (18 micrograms/90 min) in a hypogonadotrophic hypogonadal male has been studied. Before treatment the patient was azoospermic and had low testosterone (1.2 nmol/l) with low and apulsatile immunoreactive LH (1.9 +/- 0.2 IU/l) and FSH (1.4 +/- 1.9 IU/l) levels. There was no detectable LH bioactivity. During the first 24 h of GnRH therapy there was a small increase in immunoreactive (5.4 +/- 0.8 IU/l) and bioactive (6.7 +/- 1.3 IU/l) LH, with an irregular pattern and little effect on testosterone production (2.2 nmol/l). Within 1 week of treatment both bioactive (30.5 +/- 6.8 IU/l) and immunoreactive (13.6 +/- 1.5 IU/l) LH levels were above the normal range and the pattern of secretion was pulsatile. The bioactive to immunoreactive (B:I) LH ratios within the pulses (2.6 +/- 0.3) were higher (P less than 0.01) than between pulses (1.97 +/- 0.1) and the testosterone concentration (17.8 +/- 2.1 nmol/l) was now normal. At one month LH secretion was similar and testosterone pulses of high amplitude were evident corresponding to high-amplitude bioactive LH pulses. By 3 months mature spermatozoa (1.3 x 10(6)/ml) were seen in the patient's semen. The pattern of LH secretion was pulsatile but the levels of bioactive (13.1 +/- 3.6 IU/l) and immunoreactive (9.5 +/- 1.3 IU/l) LH decreased towards the normal range reflecting maturation of the testicular feedback control at the pituitary level. This effect was more pronounced on bioactive rather than immunoreactive LH secretion (57% vs 32% relative decrease). At 6 months LH levels were similar and the sperm count was normal (34 x 10(6)/ml).

Adult↗
PubMed1989

The effects of 24% paraquat (1,1'-dimethyl-4,4'-bipyridylium dichloride) on hemodynamics, blood gases, plasma lactate and plasma catecholamines in dogs.

The cause of death after ingestion of a large dose of paraquat is unclear. We investigated the cardiovascular effects of paraquat injection in 7 dogs that were anesthetized with urethane and alpha-chloralose and maintained on controlled ventilation. After control measurements, paraquat (20 mg/kg) was injected iv. Average concentrations of plasma paraquat were 128 micrograms/ml at 15 min (point 1) and 44 micrograms/ml at 4 hr. The average time of survival was 5.5 +/- 2.2 hr. Comparison was made of control values, 15 min (point 1), and 2.5 +/- 1.0 hr before death (point 2). Pulmonary capillary wedge pressure (+33%) and pulmonary vascular resistance (PVR) (+28%) increased, but no change occurred in mean arterial pressure (MAP) or cardiac output (CO) at 15 min. Mean arterial pressure (-50%) and cardiac output (-61%) decreased, while total vascular resistance (+56%) and PVR (+256%) were increased at point 2. Arterial pH decreased from 7.394 and 7.307 (point 1) to 7.143 (point 2). The concentration of plasma catecholamines and lactic acid increased significantly at both points 1 and 2. Renal, adrenal and myocardial tissues were studied by light and electron microscopy. The outstanding feature was early swelling of mitochondria and disruption of the contents in the presence of intact mitochondrial membrane.

Animals↗
PubMed1985

Characteristics and perceptions of after-hours callers.

After-hours care remains an important aspect of community practice although little is known about the views of either physicians or patients. This study presents an analysis of 12 499 after-hours calls made to a family practice centre over a five-year period, and 798 follow-up telephone interviews conducted with people who called for help after hours. Fifty per cent of the callers requested care for themselves while the remainder made the call for another family member, usually a child; most had discussed the problem with family or friends before calling. A majority stated that they would go to a hospital emergency room if they could not use the after-hours service. Physicians tended to perceive the calls as being due primarily to physical problems, while almost one-third of the callers stated that the motive for their call was anxiety or concern rather than physical discomfort. Although there was a lack of agreement between physician and caller on several aspects of the contact, most of the callers were satisfied with the contact.

Adolescent↗
PubMed1985

[Pregnancy in adolescents].

225 women aged less than 18 years of age at the start of their pregnancies were seen in the Saint Antoine Hospital between July 1977 and December 1983 (1.2%). These pregnancies were studied using data-processing. From the sociological angle there were two main groups. There were on-dwelling French women (29.3%) and African women (27.1%). These groups could be compared according to the total number of women who were married (35% French girls and 95% in the Africans) and the age of the partner and his professional activity. 46 patients had already had one previous pregnancy of which 29 delivered at term. In 25% of the pregnancies there were fewer than 4 antenatal consultations. There was a rise in the numbers of premature labours (22.2%) and only a small number of cases of toxaemia (4.4%). The caesarean section rate was 9.3%. The average weight of the newborn was 3110 g. The perinatal mortality rate was 8 per 1000. The conclusions that can be drawn are that pregnancies in adolescents who attend the Saint Antoine Maternity Hospital are "at risk" pregnancies, but the percentage who are at risk is fewer than in many other countries.

Adolescent↗
PubMed1982

Measurement of adenosine triphosphate and some other metabolites in blood cells by isotachophoresis. II. Application to monitoring changes during storage in acid-citrate-dextrose preservative.

The applicability and accuracy of isotachophoresis in measuring the concentrations of some of the intermediates of red cell metabolism during blood bank storage in acid-citrate-dextrose preservative was assessed. Preparative treatment consisted of washing with isotonic sucrose solution and centrifugation to remove serum, but white cells and platelets were not separated out from red blood cells. The results for 2,3-diphosphoglycerate, ATP, inorganic phosphate and lactate were also confirmed enzymatically. The technique had good reproducibility (variation less than 3%) and was extremely convenient compared to traditional enzyme assays of the same components. It enabled simultaneous measurement of components with concentrations greater than 1 mumole/red blood cell.

2,3-Diphosphoglycerate↗
PubMed1982

Direct withdrawal of zones during preparative capillary type isotachophoresis.

This study used a Shimadzu IP-1B capillary type isotachophoretic apparatus with a potential gradient detector. An ipp-1 withdrawal cell was fitted to this and a technique for withdrawing individual components directly through this port was developed using a microsyringe. The recovery rate was up to 45% for individual target components. When 100% withdrawal of the target component was attempted by withdrawing a volume four times the calculated volume (so that the zones both before and after the target component were also included), the best recovery rate was only 78%. In all cases, the results varied less than 3%. The limit for analysis of individual components of a 0.01 M solution was around 3 microliters. If this volume was exceeded, the ion quantity was too large for the volume of the microcapillary tube and mixed zones formed such that complete separation and analysis of individual components became impossible.

Citrates↗
PubMed1982

Measurement of adenosine triphosphate and some other metabolites in blood cells by isotachophoresis. I. Preparative technique and enzymatic confirmation.

This study investigated the optimal conditions for detection of nucleotides in blood using an IP-1B capillary isotachophoretic apparatus. The system used 10 mM HCl-beta-alanine (pH 4.2) as the leading electrolyte and n-caproic acid as the terminal electrolyte. Direct application of lysed red blood cells was shown to be inaccurate, and a method of deproteinization based on heat in a microwave oven was developed. The zones for 2,3-diphosphoglycerate, ATP, inorganic phosphate, and lactate were identified enzymatically by withdrawal of pure samples of each zone via a special withdrawal cell. The quantitative values obtained by isotachophoresis were also confirmed enzymatically. The technique is now available for convenient and accurate identification of these metabolites simultaneously.

Adenosine Diphosphate↗
PubMed1981

The telephone in primary care.

This paper presents a review of the use of the telephone in primary care medicine. The telephone is available to a large majority of United States citizens, a situation that is unusual in other countries. Between 15 and 20% of all primary medical contacts in the United States occur on the telephone. Approximately 40% of routine office telephone contacts are administrative in nature, the remainder involving direct requests for advice or treatment. After office hours, requests for immediate medical advice constitute almost all of the calls (for both daytime and after hours calls). Close to 70% of the medical calls are managed solely by use of telephone. Although the telephone is effectively used for medical consultation, teaching and survey purposes, it has been shown that health professionals are protocols or specific training tends to improve performance, but such programs are not a regular part of medical education.

Communication↗