Biomedical subjects
Publications and source records attributed to M Jacobs.
Five newborn infants who developed subaponeurotic haemorrhage are described. Three infants were delivered by vacuum extraction, and 3 infants died. The importance of early diagnosis and prompt treatment is emphasized.
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The authors reviewed 181 patients who received local radiation therapy for the prevention or control of extramedullary disease resulting from acute leukemia. 126 had acute lymphocytic leukemia and 55 had acute granulocytic leukemia. They were treated over a 18-year period of time with different forms of chemotherapy. Most had not received prophylactic CNS radiation therapy. Patients were evaluated for local control until death or hematologic relapse intervened. More than 80% of patients with clinical ALL meningeal leukemia had a successful response to doses over 1000 rads. This same response was not apparent in AML. More than 80% of clinical non-CNS extra medullary leukemia was controlled with doses of 600 rads or greater. Only one patient with extra-medullary relapse is still alive. The authors feel that lower preventative doses of radiation to the CNS are compatible with similar control rates, based on their own data and other suggestive data.
Ninety-six pre- and postanastomosis allograft biopsies from 48 transplant recipients were studied employing the direct fluorescent antibody procedure. Of the 48 transplants studied, 26 postanastomosis biopsies showed significant blood vessel wall deposits consisting predominantly of 2-4+ staining IgM and C3 deposits. The corresponding preanastomosis biopsies showed only patchy intimal surface staining. All but two of the grafts with positive biopsies had been preserved by the pulsatile perfusion method for various periods of time. Twenty-three of the twenty-six grafts with positive findings failed within 1 month while only 2 of the 19 negative postanastomosis biopsies failed within the 1-month period. Based on these findings actual graft failure occurred in 89% of the patients with postanastomosis transplant biopsies with positive findings. Although crossmatch studies were negative in all cases, further immunologic studies of eluates obtained from positive postanastomosis biopsies revealed the presence of lymphocytotoxic IgM antibodies in three of five cases studied. These findings suggest that rapid deposition of undetected preformed lymphocytotoxic antibodies accumulate in the vessel walls following anastomosis and contribute to transplant failure.
Microtubules reconstituted in vitro are identical in helical structure with tubules making up the mitotic spindle and both are formed by a helical condensation-polymerization mechanism. The protomer of microtubules is a heterodimer (alphabeta), of mol.wt. 110000 and sedimentation coefficient, SO25,w, 6S. This dimer has one binding site for colchicine or podophyllotoxin, two sites for Vinca alkaloids, two sites for guanine nucleotides and Ca2+-binding sites. There is also a beta-chain phosphoserine. Modulation of these properties is discussed as a possible way of regulating the competence of tubulin to polymerize. Reconstituted microtubules depolymerize to a mixture of 30-36S oligomeric tubulin and 6S dimer molecules. The 30-36S tubulin appears as a ring or disc when made visible in the electron microscope by negative staining. Three pathways of microtubule assembly have been proposed involving this ring as an intermediate: (1) the uncoiling of these rings into protofilaments; (2) the stacking of rings into macrotubules; (3) the rings as a scaffold for the assembly of a short segment of microtubule helix. Finally, the regulation of mitosis is discussed in terms of recent studies of tubulin and its polymerization, and studies in vitro and in vivo of the process of mitotic-spindle formation and disassembly.
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The clinical course of 130 patients treated for malignant parotid tumors at the three institutions have been reviewed. Fifty-six of these 130 patients developed recurrences following their primary treatment by a surgical procedure. There were a total of 109 recurrences among these 56 patients. The average number of recurrences was two per patient. The average survival from first recurrence was 3.7 years, with the median survival 2 years. The range of survival was 0.5 to 17 years. Once recurrence developed, treatment was by surgery, radiation therapy, chemotherapy, or a combination. Of 56 patients with recurrence, 33 are dead and 9 patients are alive with disease. Fourteen patients are alive and well with no evidence of disease. These NED patients had an average number of 1.6 recurrences and a median survival to date of only 3 years. Our study indicates that for the majority of patients who develop recurrence, survival is relatively short and treatment is usually ineffective in three of four patients. The authors conclude that after a surgical procedure for malignant salivary gland tumors, a trial of wide field postoperative radiation therapy to high dose should be considered as part of the initial treatment.
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A pH microelectrode has been used to investigate the auxin effect on free space pH and its correlation with auxin-stimulated elongation in segments of pea (Pisum sativum) stem and maize (Zea mays var. Bear Hybrid) coleoptile tissue. Auxin induces a decrease in free space pH in both tissues. In maize coleoptiles, free space pH begins to fall within about 12 minutes of exposure to auxin and decreases by about 1 pH unit by approximately 30 minutes. In pea, pH begins to decrease within an average of 15 to 18 minutes of exposure to auxin and falls by about 0.9 pH unit by approximately 40 minutes. Auxin-stimulated elongation, measured in the same two tissues similarly prepared, appears in maize at the earliest 18 minutes after auxin application, while in pea it appears at the earliest 21 to 24 minutes after auxin application. The auxin analogs p-chlorophenoxyisobutyric acid and phenylacetic acid do not stimulate elongation above control levels in maize or pea tissue segments and do not cause a decrease in free space pH in either tissue. These findings are consistent with the acid secretion theory of auxin action.
The decision on whether industrial waste should be deposited on general or special dumps depends upon the toxicity of the waste and thus upon the risk of ground-water pollution and the killing off of micro-organisms responsible for breaking down waste products. Since chemical analyses that are to provide information on toxicity are frequently very costly, an attempt was made to determine the toxicity of solid or semi-solid waste with the aid of a bacterial test. As in the perforated-plate test, here, too, the formation and size of inhibition zones were used to determine the toxicity after diffusion of substances contained in industrial waste. About 30 different types of industrial waste were examined with this method. For almost all substances a positive correlation of the (known) constituents of waste to the formation of inhibition zones was found to exist. The influence exercised by solubility and diffusibility and other problems are dealt with.
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Like indoleacetic acid, buffers of acidic pH, which stimulate elongation of pea (Pisum sativum var. Alaska) stem tissue, induce the appearance within the tissue of a watersoluble xyloglucan polymer that probably arises from previously deposited wall material. Neutral pH buffers, which inhibit the elongation response to indoleacetic acid in this tissue, inhibit indoleacetic acid-induced increase in soluble xyloglucan. The findings provide further evidence that release of soluble xyloglucan from the cell walls of pea results from the biochemical action on the cell wall that is responsible for wall extension. The data also indicate that treatment of tissue with either auxin or acidic pH has a similar biochemical effect on the cell wall. This is consistent with the H(+) secretion theory of auxin action.
Fibrosing uremic pleuritis is a newly recognized late complication of uremia. Extreme incarceration of the lining and chest wall can occur with disabling restriction of pulmonary function. Decortication of the chest wall and the lung can be carried out safely with minimal bleeding and restoration of pulmonary function.
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