Biomedical subjects
Publications and source records attributed to B Williams.
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Twenty-three surviving patients who were weaned from cardiopulmonary bypass with intraaortic balloon pump assistance returned for follow-up radionuclide left ventricular (LV) function and thallium 201 perfusion studies at a mean of 23 +/- 3 months following operation. It was found tat despite profound intraoperative myocardial depression requiring intraaortic balloon assistance, 13 patients had no change (within 10%) in the resting LV ejection fraction compared with the preoperative measurement. Among all 23 patients, there was no difference between mean (+/- standard error of the mean) preoperative and postoperative resting LV ejection fraction (48 +/- 4 vs 46 +/- 4%, p = not significant [NS]). Only 11 patients had perioperative myocardial infarction documented by new Q waves in the electrocardiogram, by elevation of creatine kinase-MB fraction, or by defects on thallium 201 imaging not explained by documented myocardial infarction before operation. Overall, postoperative resting LV ejection fraction was not different from the preoperative value in patients with perioperative myocardial infarction (44 +/- 7 vs 47 +/- 5%, p = NS). Postoperative resting LV ejection fraction rose by greater than 10% compared with preoperative values in 4 patients (3 with aortic valve replacement), remained within the 10% limit in 9 patients, and fell by greater than 10% in 10 patients (7 with perioperative myocardial infarction). Only 4 out of 16 patients studied at follow-up with exercise radionuclide studies demonstrated a normal LV response to exercise (greater than 5% increase in LV ejection fraction). Thus, among survivors requiring intraaortic balloon pump assistance for weaning from cardiopulmonary bypass, LV performance at rest is frequently preserved. In addition, 11 of the 23 patients had evidence of perioperative myocardial infarction, indicating a component of reversible intraoperative LV dysfunction.
Cells of Escherichia coli containing a chemically synthesized human alpha 1 interferon (IFN-alpha 1) gene, under control of the lac promoter, make a product with biological properties indistinguishable from those of the natural IFN-alpha 1 [antiviral activity, acid stability, species crossreactivity, inactivation by antisera directed against leukocyte or Namalwa cell interferon, and stimulation of (2'-5')oligoadenylate synthetase activity]. Similar levels of IFN synthesis were obtained when the expression unit (lac promoter plus synthetic IFN-alpha 1 gene) was transplanted into the obligate methylotroph Methylophilus methylotrophus.
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Adult patients with primary basilar impression were four times more likely to have a history of birth injury than a control group. Distortion of basicranial synchondroses during birth is suggested as a possible mechanism and, in association with hindbrain herniation and arachnoid adhesions, may contribute towards the development of syringomyelia.
Syncope is rare as a presenting symptom of syringomyelia. Three cases are described in which syncope brought the patient to hospital and in each case syringomyelia was subsequently diagnosed and treated. The suggestion is made that impaction of hindbrain hernia or the Chiari malformation may be a causative mechanism of loss of consciousness in such cases; the three examples presented all did well after posterior fossa surgery to decompress the hindbrain hernia.
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1. Although systolic blood pressure elevation is responsible for increased incidence of cardiovascular accidents in old people, the preventive benefit of lowering systolic hypertension in elderly has not been confirmed. 2. A double blind study comparing the effects of a placebo and of an active regimen (hydrochlorothiazide-triamterene with or without methyldopa) in people over 60 years with isolated systolic hypertension has been undertaken by the European Working Party on High blood pressure in the Elderly (EWPHE). 3. The actively treated group shows a lowered sitting blood pressure (-15/6 mm Hg), a mild increase of serum creatine, serum uric acid and blood glucose and a mild decrease of serum potassium after two years of treatment when compared to the spontaneous changes observed in the placebo treated group. 4. The study is continuing to evaluate if the blood pressure reduction prevents or reduces the incidence of cardiovascular accidents, although some biochemical changes were provoked by the treatment.
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The interaction between 1-desamino-8-D-arginine vasopressin (DDAVP) and human peripheral blood lymphocytes was investigated in vitro, using DDAVP concentrations ranging between 1 pg and 10 microgram per ml. DDAVP did not display any mitogenic activity in the absence of phytohaemagglutinin (PHA). Neither did DDAVP have any significant effect on the PHA-stimulated incorporation of 3H-thymidine into DNA, provided that optimally mitogenic concentrations of PHA were present. However, DDAVP either enhanced or inhibited lymphocyte transformation initiated by suboptimally mitogenic concentrations of PHA: the direction of the response depended on the magnitude of the transformation response induced by the PHA alone. Experiments employing 125I-DDAVP demonstrated that DDAVP bound reversibly to untransformed lymphocytes, and that at 20 degrees C, the amount bound increased rapidly to reach a plateau value after 60 minutes. The binding of DDAVP was inhibited in the presence of Pitressin or arginine vasopressin suggesting that human peripheral blood lymphocytes have surface receptors for the vasopressins which also react with DDAVP.
Prophylactic granulocyte transfusions prevent infections in granulocytopenic marrow transplant recipients. In this setting the selection of a single "compatible" related donor for each recipient removes many of the immunologic problems inherent in utilizing multiple random volunteer donors. Graft-versus-host disease is a real risk from granulocyte transfusions and can probably be prevented by irradiation prior to infusion. The problem of cytomegalovirus acquisition through granulocyte and other blood product donors remains to be solved.
At some stages in the replication cycle, adenovirus synthetic and related activities appear to coincide with the stimulation of host cellular metabolism while at other times, significant depression of host cellular activities seem to be caused by some or all of the same processes. The depression of host cell respiration during early (0-6 h) and late (30-36 h) stages of the virus replication cycle is most noteworthy. It has been shown that these inhibitions are connected with the effect of virus soluble antigens. Isolated antigen, relatively free of virion, affects adversely some respiratory metabolic parameters of the infected cells. Our observations are related to some early studies on virus replication processes and other observed host cellular changes.
Plasma exchange is an effective technique for removal of antibodies prior to ABO incompatible marrow grafting. However, expense and hepatitis risk make alternative methods desirable. A solid phase immunoadsorbent column using blood group A trisaccharide has been demonstrated to specifically remove anti-A antibody from human plasma in vitro and immunized dogs in vivo with no toxicity. Preliminary results in patients are encouraging.
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Admissions to the coronary-care unit at Green Lane Hospital, over the past seven years, are examined by looking at: reasons for admission, the incidence of myocardial infarction, ages of males and females, death rates and modes of death. There has been little change in the pattern of admissions and the mortality rate of myocardial infarction as seen in this coronary-care unit.