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Biomedical subjects

M Thomas

Publications and source records attributed to M Thomas.

At least 397 records · Page 22Linked to original sources

[Bronchiolitis obliterans with organizing pneumonia: differential diagnosis of pneumonia refractory to antibiotics].

HISTORY AND FINDINGS: A previously healthy 58-year-old woman was admitted with rapidly worsening dyspnoea, dry cough and subfebrile temperature. Chest radiogram showed spotty infiltrations, especially in the bases of both lungs. She was dyspnoic with mild tachypnoea (24/min) and mild cyanosis of the lips. Fine, non-resonant rales were heard over the middle and lower lobes bilaterally. INVESTIGATIONS: Erythrocyte sedimentation rate was markedly raised (97/110 mm), arterial oxygen partial pressure slightly decreased (45 mm Hg), CO2 partial pressure was 32 mm Hg. Bronchoalveolar lavage was unremarkable. TREATMENT AND COURSE: Because of the respiratory impairment broad antibiotic treatment was at once commenced empirically with gentamycin, cefotaxim, erythromycin, rifampicin and fluconazole. As the response was poor, a transbronchial lung biopsy was performed. This merely showed nonspecific lymphoplasmacellular bronchitis. An open biopsy then revealed bronchiolitis obliterans with organizing pneumonia (BOOP). Treatment with initially 75 mg prednisone daily quickly brought about improvement and the patient was entirely well after 6 months. CONCLUSION: The described constellation of history and clinical as well as radiological findings should strongly suggest BOOP. With adequate treatment the prognosis is excellent.

Anti-Bacterial Agents↗

Purification and characterization of prostaglandin-H E-isomerase, a sigma-class glutathione S-transferase, from Ascaridia galli.

Comparison of partial primary sequences of sigma-class glutathione S-transferases (GSH) of parasitic helminths and a GSH-dependent prostaglandin (PG)-H D-isomerase of rat immune accessory cells suggested that some of the helminth enzymes may also be involved in PG biosynthesis [Meyer and Thomas (1995) Biochem. J. 311, 739-742]. A soluble GSH transferase of the parasitic nematode Ascaridia galli has now been purified which shows high activity and specificity in the GSH-dependent isomerization of PGH to PGE, comparable to that of the rat spleen enzyme in its isomerization of PGH to PGD, and similarly stimulates the activity of prostaglandin H synthase. The enzyme subunit is structurally related to the rat spleen enzyme and sigma-class GSH transferases of helminths according to the partial primary sequence. The data support the hypothesis that some sigma-class GSH transferases of helminth parasites are involved in PG biosynthesis which, in the case of PGE, is likely to be associated with the subversion or suppression of host immunity. A PG-H E-isomerase of comparable specificity and activity has not previously been isolated.

Amino Acid Sequence↗

Lack of predictive value for progression of dissociated circulating P24 antigen in human immunodeficiency virus type 1-infected black patients.

In human immunodeficiency virus type 1 (HIV)-1-infected Black people, the circulating p24 antigen is hidden frequently in immune complexes, because of high titers of serum anti-p24 antibodies. In order to evaluate the prognostic values for progression of free and dissociated serum p24 antigen in Black people, sera from 45 HIV-1-infected Black patients, all at non-AIDS stages, were evaluated prospectively for p24 antigen by several assays; circulating free p24 antigen was measured by immunocapture ELISA only (method 1) and with ELAST amplification (method 2), and dissociated p24 antigen determined after glycine-HCl pretreatment of serum, by immunocapture ELISA only (method 3) and with ELAST amplification (method 4). Serum CD4 and CD8 cell counts, beta 2-microglobulin, and total IgA were determined also at least twice a year. Clinical events for AIDS were those included in the 1986 CDC classification for HIV infection. At entry, p24 antigen was found in 3 (6.7%) patients by method 1, in 7 (15.6%) by method 2, in 14 (31.1%) by method 3, and in 22 (48.9%) by method 4. Methods 3 and 4 were more sensitive than method 1 (P < 0.001) and method 2 (P < 0.001). The mean follow-up was 30 months. The free symptom survival times (mean +/- SD months) were significantly lower in patients being p24 antigen positive by method 1 [(+) 33 +/- 27 vs. (-) 61 +/- 15, P = 0.03), but they were similar in patients positive and in those negative for p24 antigen determined by method 2 [(+) 71 +/- 17 vs. (-) 74 +/- 9, P = 0.54], method 3 [(+) 76 +/- 12 vs. (-) 69 +/- 13.2, P = 0.80], and method 4 [(+) 79 +/- 9 vs. (-) 63 +/- 7, P = 0.71]. At 24 months, p24 antigen positivity did not correlate either with CD4 or CD4/CD8 slops, nor with beta 2-microglobulin or IgA variations. By contrast, a CD4 cell count below 200/mm3 at entry was significantly associated with disease progression. In conclusion, dissociated p24 antigenemia does not appear as a useful surrogate marker for progression in HIV-1-infected Black people.

Adult↗

Palliation of oesophageal carcinoma using the argon beam coagulator.

Oesophageal intubation occasionally fails to palliate inoperable carcinoma: some tumours are unsuitable for this procedure and others overgrow the tube. This study reports a series of nine patients (median age 79 (range 55-87) years) in whom the argon beam monopolar coagulator via a flexible endoscopic probe was used to ablate such tumours. Fourteen ablation procedures were performed. The endoscope was passed to the stomach at the end of each procedure. There were no complications; the median hospital stay was 2 (range 1-13) days. Thirteen procedures rendered the patients completely asymptomatic for a median of 6 (range 4-12) weeks. Six patients died a median of 14 (range 4-38) weeks after the first ablation, reflecting their limited life expectancy. The argon beam coagulator provides an effective alternative to laser ablation, being considerably cheaper and safer, while maintaining the minimally invasive nature of the palliation.

Aged↗

EMBASE remains EMBASE--on every host? A comparative analysis of EMBASE on the hosts DATA-STAR, DIALOG, DIMDI, and STN.

Differing results of the same search request processed on different hosts led the authors to investigate this issue more thoroughly. Two authors, two journal titles, two drug names, and two topics of a general medical nature were retrieved under identical circumstances and conditions on the hosts DATA-STAR, DIALOG, DIMDI, and STN. Comparing the figures revealed that none of the nine search request produced an identical result on all hosts. Some of the search results differed only slightly, while the searches in the basic index produced considerable discrepancies.

Databases, Bibliographic↗

[Diagnostic imaging in bronchiectases. Value of CT and HRCT].

Various diseases can cause bronchiectasis as a result of inflammatory bronchial wall damage. The diagnosis is based on imaging techniques, which are also required to assess the extent and localization of dilated bronchi and possible causes. Chest radiography only occasionally allows the diagnosis of bronchiectasis (Fig.2) and is usually not a sufficient basis for therapeutic decisions (Fig. 1a), but it is important for follow-up studies. Bronchography (Fig.1b) was considered the diagnostic procedure of choice in suspected bronchiectasis for decades. Being an invasive procedure, it has recently been almost completely replaced by computed tomography (CT), which can also demonstrate associated pulmonary abnormalities (Fig.6) in addition to visualizing the bronchi. CT diagnosis of bronchiectasis is based on the demonstration of bronchial dilatation relative to the adjacent pulmonary artery (Figs. 4, 5, 7-9), lack of bronchial tapering (Figs. 3, 4, 10) and visualization of bronchi in the lung periphery (Figs. 3, 5, 8, 10). In suspected bronchiectasis high-resolution scans should be obtained during inspiration. Contiguous, thicker slices or scans taken during expiration may be required in particular cases.

Bronchiectasis↗

[Bronchiolitis obliterans with organizing pneumonia (BOOP). Clinical aspects, pathology and radiologic images].

Bronchiolitis obliterans with organizing pneumonia (BOOP) is a clinicopathological syndrome of unknown etiology. Histopathologically, it is characterized by plugs of fibroplastic connective tissue within respiratory bronchioles, mononuclear cell infiltrates in parenchyma adjacent to the affected bronchioles and foam cells within alveolar air-spaces. The disease usually presents as a subacute illness with complete resolution. A subset of BOOP, however, is associated with a fulminant course and a high lethality due to respiratory failure. Early diagnosis and therapy are mandatory. Chest radiography, computed tomography (CT), bronchoalveolar lavage (BAL) and open lung biopsy are the primary diagnostic techniques. Radiographically, BOOP is characterized by patchy areas of consolidation that are usually bilateral, peripheral and often migratory. In some cases small, round opacities may be observed as the only abnormality. CT can show the pattern of ground glass opacities, areas of airspace consolidation and small, round opacities, while considerable fibrotic change is usually not seen. A reticular roentgenographic pattern, fibrotic changes mainly in subpleural location at CT, lack of lymphocytosis in BAL fluid and histological features of usual interstitial pneumonitis and BOOP in biopsy specimens are all considered risk factors for a fatal outcome.

Adult↗

Tendon shift in hallux valgus: observations at MR imaging.

OBJECTIVE: This study was undertaken to demonstrate a shift in tendon alignment at the first metatarsophalangeal joint in patients with hallux valgus by means of magnetic resonance imaging. DESIGN: Ten normal feet and 20 feet with the hallux valgus deformity conforming to conventional clinical and radiographic criteria were prospectively studied using magnetic resonance imaging. Correlation was made between tendon position at the first metatarsophalangeal joint and the severity of the hallux valgus deformity. RESULTS: There is a significant shift in tendon position at the first metatarsophalangeal joint of patients with hallux valgus. The insertion of the abductor hallucis tendon is markedly plantarward and the flexor and extensor tendons bowstring at the first metatarsophalangeal joint compared with patients without the deformity. The severity of the tendon shift correlates with the hallux valgus angle and clinical severity of the hallux valgus deformity in each case. CONCLUSION: Patients with hallux valgus have a significant tendon shift at the first metatarsophalangeal joint which appears to contribute to development of the deformity.

Case-Control Studies↗

Re-evaluation of two simple prognostic scores of outcome after proximal femoral fractures.

The Belfast and Newcastle simple prognostic scores of outcome after treatment of proximal femoral fractures were recorded shortly after admission on 250 patients. All patients were then followed until discharge, with 87 of those who were the more physically and socially dependent before admission being transferred after surgery for rehabilitation in a geriatric unit. The hospital mortality rate, a hospital stay of over 6 weeks and two measures of rehabilitation outcome, i.e. a delay of over 3 weeks after the operation in regaining independent mobility and any functional decline on discharge compared with the preadmission situation, were recorded for each patient. The prediction of a higher hospital mortality rate and a delay in reaching independent mobility in more dependent patients with both scores reached statistical significance. Longer hospital stays in the more dependent patients did not occur in a situation where care facilities for dependent patients were readily available. The scores, in particular the Belfast score, can be used to compare the casemix of patients with proximal femoral fractures within and between units over time and can predict mortality and delay in achieving independent mobility. They may be helpful in the early selection of patients for transfer to a geriatric unit or orthogeriatric unit for rehabilitation.

Aged↗

Monitoring of antibiotic use in a primary and tertiary care hospital.

Prophylactic and curative use of antibiotics was studied prospectively in 87 consecutive medical and surgical cases of a tertiary care hospital and in 98 cases of a primary care hospital. Based on Kunins' criteria, antibiotic prophylaxis was found to be more inappropriate in the primary care hospital (49%) than in the tertiary care hospital (34%). Antibiotic therapy, however, was more appropriate at the primary level; 67% as opposed to 60% at the tertiary level. This resulted in a similar overall level of inappropriate antibiotic use in the two hospitals. Surgical prophylaxis was started postoperatively in 68% of the primary care hospital cases. Though prophylaxis was always perioperative in the tertiary care hospital, the postoperative duration was more than 7 days in one third of the cases. The nosocomial infection rate in those given prolonged prophylaxis was higher than those who received antibiotics for less than 72 hours. Antibiotics were started empirically in 78% of tertiary hospital care cases and 100% of cases in the primary hospital. Though culture sensitivity was done in 80% of the tertiary care cases, more than half the specimens were sent after multiple doses of antibiotics were started. The choice of antibiotic did not always correlate with the sensitivity report. Though cost-effective drugs were chosen in 50% of cases, in more than 20% of cases expensive drugs were started. The study highlights the need for an antibiotic audit and suggests the necessity of having an ongoing peer audit.

Anti-Bacterial Agents↗

The reduction of radiation mucositis by selective decontamination antibiotic pastilles: a placebo-controlled double-blind trial.

The aim of this study was to see if antibiotic pastilles could reduce radiation mucositis, pain, dysphagia and weight loss in patients undergoing radical radiotherapy for head and neck cancer. A total of 275 patients with T1-T4 tumours entered the study; 136 were allocated to suck four times daily a pastille containing amphotericin, polymyxin and tobramycin. The remaining 139 patients received an identical placebo. In all, 54 patients were unevaluable (24 active, 30 placebo). Bacteriological monitoring was carried out before and twice weekly during treatment. Both arms of the study were well balanced for T and N stage, age, sex and radiation dose (60 Gy). There was a slight imbalance in the site of disease which had no substantive effect on the results. The primary study end point was the percentage of patients who developed intermediate or thick pseudomembranes. No statistically significant difference was found in this end point, with 36% of patients in the active arm developing this type of membrane compared with 48% in the placebo arm (P = 0.118). The estimated odds ratio (placebo/active) of developing an intermediate or thick pseudomembrane was 1.59 (95% CI 0.89-2.82). However a more sensitive test comparing the worst recorded mucositis grade between the two arms was statistically significant (P = 0.009). This indicated that the active pastilles had a beneficial effect, but the magnitude was probably smaller than the trial was designed to detect. There was a reduction in mucositis distribution (P = 0.002), mucositis area (P = 0.028), dysphagia (P = 0.006) and weight loss (P = 0.009) in the active arm. There was a clear tendency for patients with positive cultures for aerobic Gram-negative bacteria (AGNB) (P = 0.003) and yeasts (P = 0.026) during treatment to have more severe mucositis. The active pastilles reduced the percentage of patients with yeast cultures (P = 0.003) but had less effect on AGNB. The benefit derived from the pastilles should materially increase patient tolerance to radical radiotherapy for head and neck cancer.

Adult↗

Estrogen surge: a regulatory switch for superoxide radical generation at implantation.

This study is undertaken to identify the regulatory switch for the activation of superoxide radical generation pathway and repression of superoxide dismutase (SOD) at the time of implantation using estrogen as a control factor and delayed implantation as a model system. The results revealed high SOD activity and negligible oxyradical generation in progesterone-treated animals on day-5 and day-8 (delayed implantation) while an enormous rise in oxyradical generation and an abrupt fall in SOD in animals which received both estrogen and progesterone injections were observed on days 5 and 8 of pregnancy. These results strongly suggest that estrogen regulates superoxide anion radical generation by lowering the SOD activity.

Animals↗

Leg power in young women: relationship to body composition, strength, and function.

The ability to generate high forces at high velocity (power) is an important component of physiologic reserve for both athletic performance and functional capacity. A comparison was made between different laboratory methods and field tests designed to evaluate leg power. Nineteen young healthy untrained women participated in this study. Maximum power during the double leg press (KP) occurred between 56-78% of the one repetition maximum (1-RM) and averaged (404 +/- 22 W). Rank-ordered correlation showed an association between KP and another measure of leg power measured on the leg extensor power rig (LR) when expressed per kg LBM (Rho = 0.565, P < 0.016). KP was also related to the 1-RM achieved on the double leg press (R2 = 0.584, P < 0.001). The KP test also correlated with the vertical jump (R2 = 0.538, P < 0.004) and maximal power output during the Wingate anaerobic power test (R2 = 0.299, P < 0.015). However, double leg press power was not related to time to run 40 yards (R2 = 0.020, P < 0.573) or maximal gait velocity (R2 = 0.136, P < 0.121). These results suggest that maximal power during the double leg press occurs at a higher percentage of maximal strength than previously reported. Double leg press power was related to vertical jump performance, validating this field test as a measure of leg muscle power in young women.

Adult↗