PubMed Health⌕ Search

Biomedical subjects

L Blesovsky

Publications and source records attributed to L Blesovsky.

11 recordsLinked to original sources
PubMed1987

Chemoreflex modulation of ventilatory dynamics during exercise in humans.

The precision of arterial blood gas homeostasis following a change of work rate depends on the response kinetics of ventilation. The carotid bodies (CB's) have been proposed as modulators of these kinetics. The present investigation was undertaken to determine whether the effect is specific to CB activation or whether other factors that augment the exercise hyperpnea would produce a similar response. We therefore established the effects of increased CB and central (C) chemoreflex activation on the inspired ventilatory (VI) dynamics for moderate-intensity cycling. Work tests were separately performed with air, 12% O2 to increase CB activity, 100% O2 to "abolish" CB activity, and CO2 in O2 to increase C activity. The time constant of the VI response was substantially shortened by hypoxia (40 s) compared with air breathing (58 s) and increased by 100% O2 (92 s) and, even more so, by CO2 in O2 (101 s). We conclude that increased carotid (but not central) chemoreflex responsiveness speeds the kinetics of the exercise hyperpnea by a process that is not merely the consequence of increased ventilatory drive.

Adult↗
PubMed1984

Local recurrence following 'curative' surgery for large bowel cancer: I. The overall picture.

The Large Bowel Cancer Project is a collaborative prospective study of 4228 patients with a histologically proven adenocarcinoma, of whom 2336 (55 per cent) survived a 'curative' resection. Follow-up information is available on 2220 patients (95 per cent). Subsequently, 309 (14 per cent) have developed a local recurrence confirmed by: biopsy (127; 41 per cent), clinical examination (77; 25 per cent), X-ray (15; 5 per cent), a raised CEA (2; 1 per cent), or some other method - e.g. CT scan or a confident unbiopsied laparotomy finding (88; 29 per cent). Statistically significant factors (chi2 test, P less than 0.05) associated with local recurrence are: Dukes' classification: A 4 per cent; B 13 per cent; C 18 per cent Tumour differentiation: Well 11 per cent; Moderate 14 per cent; Poor 21 per cent Obstruction: Absent 13 per cent; Present 21 per cent Perforation: Absent 13 per cent; Present 28 per cent Tumour mobility: Freely mobile 11 per cent; Others 21 per cent Operation performed (rectal and rectosigmoid tumours): Abdomino-perineal 12 per cent; Anterior resection 18 per cent; Surgeon (Consultant only): Range less than 5 per cent to greater than 20 per cent. Stratification of the above variables altered only the statistical significance pertaining to tumour differentiation (P less than 0.1, d.f. = 2). In particular, the differences between Consultant surgeons remained.

Adenocarcinoma↗
PubMed1984

Local recurrence following 'curative' surgery for large bowel cancer: II. The rectum and rectosigmoid.

1988 patients with an adenocarcinoma of the rectum (1292; 65 per cent) or rectosigmoid (696; 35 per cent) have been studied. A resection (1700 patients) or polypectomy (124 patients) was performed in 1824 (92 per cent) and, of the former, 1376 patients either underwent abdominoperineal (AP) excision of the rectum (788 patients) or an anterior resection (598 patients). The in-hospital mortality was 63 patients (8 per cent) for AP and 44 (7 per cent) for anterior resection, and a curative resection had been performed in 504 (71 per cent) of those undergoing an AP, and 393 (71 per cent) of those undergoing an anterior resection. Follow-up information is available for 478 patients (95 per cent) who underwent an AP and 370 (94 per cent) who underwent an anterior resection. More patients have developed a local recurrence after an anterior resection (67; 18 per cent) than after AP (57; 12 per cent) (Logrank chi2 = 6.6, d.f. = 1, P less than 0.02) (stratified for sex and Dukes' stage). This difference is not accounted for by a lesser margin of distal clearance after an anterior resection; firstly because the margin of clearance was not different in those who did and those who did not develop a local recurrence (AP: whole group = 4.4 cm, local recurrence = 4.5 cm; anterior resection: whole group = 3.0 cm, local recurrence = 3.1 cm) and secondly because for each centimetre of distal clearance there was a consistently greater probability of recurrence for anterior resection (Logrank chi2 = 9.1, d.f. = 1, P less than 0.01) (stratified for sex, Dukes' stage and distal clearance margin).

Adenocarcinoma↗
PubMed1984

Large bowel cancer: surgical pathology and its relationship to survival.

Modifications of Dukes' (1932) classification of rectal tumours have led to confusion. From the data of 2518 patients who had undergone curative colorectal surgery the interrelationships between tumour penetration, grade, vascular invasion and pattern of lymph node involvement have been examined and their individual relevance to survival determined. Subdivision of Dukes' A cases into those confined to the muscularis mucosae (A) and those penetrating into, but not through, the bowel wall (B1) should be abandoned. Despite interrelationships between lymph node status, grade of tumour and vascular invasion, they all contribute prognostic information independent of each other. Apical lymph node involvement, more than four lymph nodes involved and extensive primary tumours with nodal involvement all carry a bad prognosis. Although interrelated each variable is individually relevant. However, subgroups of patients with Dukes' C tumours have an observed survival significantly better than expected. When few lymph nodes are involved or the primary tumour is confined to the bowel wall but lymph nodes are involved, the expectation of life is equivalent to Dukes' B.

Adenocarcinoma↗
PubMed1984

Covering stoma for elective anterior resection of the rectum: an outmoded operation?

A prospective multicenter study of the management of large bowel cancer recorded the results in 4,500 patients in whom 2,056 have had an elective colorectal anastomoses. Of these patients, 15.8 percent had a synchronous covering stoma to protect the anastomoses. Although the anastomotic leak rate was high in patients with a stoma, no overall differences were observed in mortality between those patients who had a covering stoma and those patients who did not (7 percent and 6.1 percent, respectively). However, when surgical policies were analyzed, clinically large and statistically significant differences were found. Some surgeons frequently used a covering stoma for low anterior resection whereas others only rarely did so. The differences in anastomotic leak and mortality were 20 percent and 7.8 percent, and 8.4 percent and 3.6 percent, respectively. We conclude that all surgeons should know their own clinical and radiologic anastomotic leak rate. If and when this figure becomes low (less than 5 percent), the covering stomas will become necessary except for the very rare and difficult case.

Adenocarcinoma↗
PubMed1983

Preoperative urography in large bowel cancer: a useless investigation?

The utility of intravenous urography (IVU) in the preoperative assessment of patients with adenocarcinoma of the large bowel has been investigated in 4226 patients derived from a prospective multicentre study entitled the Large Bowel Cancer Project. An IVU was carried out in 956 of these patients (22.6 per cent), subsequent surgery revealed unsuspected direct urinary tract involvement in 75. However, 42 (56 per cent) had shown no IVU abnormality. Twenty patients having a clinical colovesical fistula had had a preoperative IVU. Only half showed an abnormality. In the entire study group, 10 nephrectomies and 40 other concomitant urinary tract resections were performed. Four of these nephrectomies were associated with right-sided tumours. A significantly higher number of patients with a rectal primary had a preoperative IVU. The value of routine preoperative urography before large bowel cancer surgery is questioned, and other methods of determining function in the other kidney before nephrectomy should be sought.

Adenocarcinoma↗
PubMed1981

Histopathology reporting in large bowel cancer.

A review of histopathology reports on 2046 patients in the large bowel cancer project showed considerable observer variation in histological grading. Dukes staging, and lymph node harvest. These parameters have a well-established relationship to prognosis, but, if they are to be applied for both clinical and research purposes, they must be assessed consistently. A minimal level of information which should be recorded from a resection specimen is suggested, with a description of the methods by which this information can be obtained.

Adenocarcinoma↗
PubMed1980

Anastomotic integrity after operations for large-bowel cancer: a multicentre study.

Clinically evident anastomotic dehiscence was studied in 1466 patients who had undergone resection of a large-bowel adenocarcinoma. The overall incidence of anastomotic leakage was 13%, but the incidence varied between surgeons (range 0.5% to over 30%). Morbidity and mortality were significantly higher in those patients in whom the anastomosis failed to heal primarily. If these results are extrapolated to the national level, it should be possible by achieving results closer to those in patients without leakage to reduce overall post-operative mortality after resection of large-bowel cancer by 2% and to achieve an appreciable reduction in morbidity. Both factors are clinically important and, taken together, could result in appreciable saving of revenue.

Adenocarcinoma↗
PubMed1979

Large-bowel obstruction caused by cancer: a prospective study.

Patients with obstructing large-bowel cancer may be treated by primary tumour resection or the conventional staged tumour resection, and a prospective study comparing these two treatments was carried out. The post-operative outcome in 174 patients (of whom 90 underwent primary and 47 staged tumour resection) showed that the overall mortality was similar in both groups but that the duration of hospital stay in patients who underwent primary tumour resection was half that of those who underwent staged tumour resection. The mortality for primary tumour resection, however, was unexpectedly high for lesions proximal to the splenic flexure and unexpectedly low for lesions distal to this point. Of patients with distal tumours in whom a staged resection was planned, 35% died after a loop colostomy. The most striking result was that the ratio of postoperative death for trainee surgeons compared with fully trained surgeons was 3:1. It is concluded that patients with large-bowel cancer who present with intestinal obstruction should be treated by a fully trained surgeon and that immediate resection of the tumour should be considered for every patient.

Aged↗