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Biomedical subjects

M White

Publications and source records attributed to M White.

At least 379 records · Page 21Linked to original sources

The influence of surgical operations on components of the human immune system.

Surgical operations have been shown to cause a variety of immunological disturbances in man both in vivo and in vitro. With few exceptions the overall picture is one of a generalized state of immunodepression in the postoperative period. The implications of these observations are that host defences may be compromised by surgical procedures, thus providing a 'fertile soil' for bacterial invasion and tumour cell metastasis at the very time when risks from invading pathogens and viable tumour cells are maximal. We have studied the effects of surgical operations on the immune system in 35 patients with benign disease. Surgical procedures were classified as either minor (n = 15) or major (n = 20). A panel of monoclonal antibodies was used to identify peripheral blood lymphocyte subpopulations and analysis was performed using flow cytometry. Simultaneous estimations of plasma alpha-1 proteinase inhibitor (alpha-1-PI), alpha-2-macroglobulin (alpha-2-M), alpha-2-pregnancy-associated glycoprotein (alpha-2-PAG) and plasma suppressive activity (PSA) on stimulated allogeneic lymphocytes were performed before operation and on postoperative days 1, 3, 7, 17 and 21. Circulating numbers of all lymphocyte subpopulations fell significantly following surgery, except for B lymphocytes which did not change. The magnitude, and duration of the reduction in cell numbers and the subpopulation affected was significantly related to the degree of surgical trauma, and returned to pre-operative values by postoperative day 7. Changes in alpha-1-PI, alpha-2-M, alpha-2-PAG and PSA were also significantly related to the degree of surgical trauma, and these plasma changes persisted longer than the cellular disturbances. Surgical operations induce a reversible depression of cellular immunity which precedes plasma suppressive activity in its return to pre-operative levels. Immunostimulating agents such as interferon and the interleukins deserve evaluation as prophylactic agents pre-operatively.

Blood Proteins↗

Development of a new human breast cancer cell line Ia-270.

A new human breast cancer cell line (Ia-270) has been isolated from a malignant pleural effusion from a woman with metastatic infiltrating ductal carcinoma of the breast. This cell line contains cytoplasmic estrogen (ER) and progesterone (PR) receptors. Following estradiol (E2) administration, PR synthesis is augmented and a higher level of saturation density is reached. In an athymic mouse, the cell line produced a tumor morphologically similar to the primary tumor. The results of isoenzyme and karyotype analyses demonstrate Ia-270 to be of human origin and free of HeLa cell contamination. The cell line has been maintained in continuous culture since April 1982 and may provide a useful in vitro system for studying the biology of human breast cancer.

Aged↗

Counterphase lightness induction.

When half-cycle wide mid-grey test elements are superimposed on a black and white square wave induction grating, their apparent lightness is a linear function of their phase relationship with the induction grating; being judged lightest when in phase with the black bars of the grating, and darkest when in phase with the white bars. This finding justifies the use of the term "counterphase induction" to describe the effect, and emphasizes the similarity between this effect and McCourt's (1982) [Vision Res. 22, 119-134] grating induction effect. The fact that the same linear function holds whether the test elements are square or rectangular favours a global over a local explanation.

Female↗

Development and characterization of a human ovarian cancer cell line which clones without agar in vitro.

A new human ovarian cancer cell line has been initiated which clones without agar in vitro. The cell line has been characterized by growth of a tumor resembling the primary tumor in a nude mouse, by human lactic dehydrogenase isozyme pattern, by human karyotype, and by lack of contamination by other cell lines. Initial studies have demonstrated the presence of epidermal growth factor receptors in this cell line. The utility of this line for clonogenic studies is demonstrated by dose-response studies with doxorubicin, cisplatinum, and 13-cis-retinoic acid.

Agar↗

The assessment of children with school problems: evaluation of a hospital-based multidisciplinary clinic.

A hospital based multidisciplinary clinic for the assessment of children with school problems was evaluated. Questionnaires were sent to parents and teachers of 44 children seen during the first year of operation of the clinic. The majority of parents found the assessment and report valuable in answering their questions about the child; felt the report was clear and helpful, and the recommendations appropriate and practical. Ninety per cent of recommendations made were implemented. These results indicate that such clinics would seem to be an appropriate way to address the needs of children with school problems, an important segment of the new paediatric morbidity.

Adolescent↗

Effects of coronary sinus pressure elevation on coronary blood flow distribution in dogs with normal preload.

Coronary sinus pressure (Pcs) elevation shifts the diastolic coronary pressure-flow relation (PFR) of the entire left ventricular myocardium to a higher pressure intercept. This finding suggests that Pcs is one determinant of zero-flow pressure (Pzf) and challenges the existence of a vascular waterfall mechanism in the coronary circulation. To determine whether coronary sinus or tissue pressure is the effective coronary back pressure in different layers of the left ventricular myocardium, the effect of increasing Pcs was studied while left ventricular preload was low. PFRs were determined experimentally by graded constriction of the circumflex coronary artery while measuring flow using a flowmeter. Transmural myocardial blood flow distribution was studied (15-micron radioactive spheres) at steady state, during maximal coronary artery vasodilatation at three points on the linear portion of the circumflex PFR both at low and high diastolic Pcs (7 +/- 3 vs. 22 +/- 5 mmHg; p less than 0.0001) (1 mmHg = 133.322 Pa). In the uninstrumented anterior wall the blood flow measurements were obtained in triplicate at the two Pcs levels. From low to high Pcs, mean aortic (98 +/- 23 mmHg) and left atrial (5 +/- 3 mmHg) pressure, percent diastolic time (49 +/- 7%), percent left ventricular wall thickening (32 +/- 4%), and percent myocardial lactate extraction (15 +/- 12%) were not significantly changed. Increasing Pcs did not alter the slope of the PFR; however, the Pzf increased in the subepicardial layer (p less than 0.0001), whereas in the subendocardial layer Pzf did not change significantly. Similar slopes and Pzf were observed for the PFR of both total myocardial mass and subepicardial region at low and high Pcs. Subendocardial:subepicardial blood flow ratios increased for each set of measurements when Pcs was elevated (p less than 0.0001), owing to a reduction of subepicardial blood flow; however, subendocardial blood flow remained unchanged, while starting in the subepicardium toward midmyocardium blood flow decreased at high Pcs. This pattern was similar for the uninstrumented anterior wall as well as in the posterior wall. Thus as Pcs increases it becomes the effective coronary back pressure with decreasing magnitude from the subepicardium toward the subendocardium of the left ventricle. Assuming that elevating Pcs results in transmural elevation in coronary venous pressure, these findings support the hypothesis of a differential intramyocardial waterfall mechanism with greater subendo- than subepi-cardial tissue pressure.

Animals↗

Lesser sac abscesses and fluid collections: drainage by transhepatic approach.

Twelve abscesses and fluid collections in the lesser peritoneal sac were drained percutaneously using an access route across the intervening liver. This rather unusual access was chosen when other approaches were contraindicated because of surrounding colon, stomach, or spleen. All collections were drained successfully, and no specific complications such as hemorrhage, bile leak, or liver abscess occurred. Placement of an abscess drainage catheter should be done through the peripheral portion of the liver if possible. The technique offers a new, safe approach to percutaneous drainage of hitherto inaccessible collections.

Abscess↗

Cryothermal mapping of recurrent ventricular tachycardia in man.

Intraoperative reversible cryothermal mapping of recurrent ventricular tachycardia was performed in seven patients with left ventricular aneurysms with use of a 0 degrees C ice probe. A single, reproducible cryotermination site was found in each patient. The cryotermination site was uniformly located in an area where local electrograms obtained during ventricular tachycardia showed electrical activation during the diastolic portion of the surface electrocardiogram, and was different than the site of activation coincident with the onset of the QRS complex on the surface electrocardiogram (earliest reactivation site or ERS) by 4.5 +/- 2.7 cm (mean +/- SD) in five of seven patients. Sinus rhythm late potentials were recorded at the cryotermination site in five of six patients and from the ERS in one. In five patients, extensive subendocardial resection including both the ERS and cryotermination sites was performed. In two patients only the cryotermination site was excised. In six survivors, including one in whom only the cryotermination site was excised, ventricular tachycardia could not be induced 2 weeks after surgery and has not recurred during the follow-up period of 7 to 17 months (12 +/- 4.5 months, mean +/- SD). Reversible cryothermal mapping may provide additional important information not obtained by standard electrogram mapping of ventricular tachycardia that may help guide surgical therapy of recurrent ventricular tachycardia.

Cold Temperature↗

Psychological consequences of infestation of the dwelling unit.

Interview data from a three-wave panel study of the impact of the residential environment upon the psychological well-being of 337 minority women were used to examine the effects of household infestation upon self-reported depression, phobic anxiety, somatization, hostility, and anomia. The findings of cross-sectional and change analyses over the three waves of data point to a stable relationship between rat infestation and a single dimension of psychological well-being, somatization.

Animals↗

Percutaneous drainage of postoperative abdominal and pelvic lymphoceles.

Eleven patients with postoperative abdominal and pelvic lymphoceles underwent percutaneous diagnostic and therapeutic intervention with either needle aspiration or catheter drainage. Although initial sonographic or CT examinations accurately identified these collections, definitive diagnosis required fluid sampling and laboratory analysis for confirmation. Seven pelvic and two retroperitoneal lymphoceles demonstrated a gross appearance and composition different from two lymphatic collections in the upper peritoneum. Nine patients underwent catheter drainage; two were managed by needle aspiration alone. Duration of catheter drainage was 4-120 days, substantially longer than is customary for standard fluid collections. Nine of 11 patients were cured by percutaneous aspiration or drainage alone. Bacterial colonization developed in three persistently draining lymphoceles. However, no clinical sepsis or bacteremia occurred. In another patient with persistent high-volume lymphatic output, sclerotherapy with tetracycline instillation was successful in rapidly closing the lymphatic fistula. Percutaneous drainage is a safe, effective procedure for drainage of postoperative lymphoceles.

Adult↗

An evaluation of treatment outcome for psychiatrically hospitalized adults.

The need for well-conducted outcome studies has become more critical in recent years due to the increasing demands of third-party payers for demonstrations of the efficacy of inpatient psychiatric treatment. This study evaluated whether or not improvements made by psychiatric inpatients during hospitalization were maintained following discharge. Patients were evaluated with measures assessing psychiatric symptomatology, social functioning, and satisfaction with treatment. These measures were administered at admission, discharge, and three and six months following discharge. Results indicated that improvements in symptomatology and social functioning were maintained three and six months postdischarge. However, patients reported less satisfaction with treatment three months after discharge than they reported at the time of discharge.

Adult↗

The effects of premedication on anaesthesia with propofol ('Diprivan').

The effects of premedication on anaesthesia with propofol (2,6-diisopropylphenol) in a dose of 2.5 mg/kg were assessed. One hundred and twenty female patients were randomized into one of three groups of 40 who received either no premedication, diazepam 10 mg orally, or pethidine 50-75 mg intramuscularly (i.m.) and atropine 0.6 mg i.m. Propofol 2.5 mg/kg was found to be a reliable induction dose. Premedication did not affect the induction time nor the incidence of side effects which occurred in 19% of patients. Apnoea occurred in 44% of patients but was not related to premedication, nor was arterial hypotension. Pain on injection was rare in the antecubital fossa but was a frequent occurrence (30%) in the dorsum of the hand. Recovery was rapid and characterized by lack of emetic sequelae; only one patient had nausea and there was no vomiting. The site of injection was examined postoperatively and venous sequelae were rare.

Adolescent↗

Circannual variation of intestinal cell proliferation in BDF1 male mice on three lighting regimens.

BDF1 male mice were studied over a 24-hr span in winter, spring, summer and fall. For three weeks prior to study, one-third of the animals were kept under a lighting regimen of 8 hr light alternating with 16 hr of darkness (LD 8:16), one-third on a lighting regimen of LD 12:12 and a remainder on a lighting regimen of LD 16:8. During each study, subgroups of animals on all three lighting regimens were killed at 4-hr intervals over a 24-hr span. Twenty minutes prior to being killed, the animals received 5 microCi of [3H]-thymidine/0.2 ml/20 gm of body weight intraperitoneally. The thymidine uptake in the DNA of the colon and of the small intestine were studied as an index of cell proliferation. A circadian rhythm in [3H]-thymidine uptake in the colon was found and validated by cosinor analysis. This rhythm was similar in acrophase and amplitude in the animals kept on LD 8:16 and LD 12:12. Also in the mice on LD 16:8, there was a statistically significant circadian rhythm of [3H]-thymidine uptake in the DNA of the colon during all four seasons. The acrophases of this rhythm, however, varied widely suggesting free running. A circadian rhythm of [3H]-thymidine uptake in small intestine was less consistent. In animals on all three lighting regimens, however, a circannual variation of [3H]-thymidine uptake in DNA in colon and small intestine was found with the highest uptake during summer. This study indicates that a lighting regimen of LD 16:8 does not reliably synchronize the circadian rhythm of [3H]-thymidine uptake in the colon. It further shows a circannual rhythm of this function in the colon and in the small intestine which persists under three lighting regimens (LD 8:16, 12:12 and 16:8) maintained for three to four weeks prior to being killed.

Animals↗