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Biomedical subjects

M Alexander

Publications and source records attributed to M Alexander.

At least 325 records · Page 18Linked to original sources

Role of radiation therapy in combination with chemotherapy in extensive oat cell cancer of the lung: a randomized study.

After 3 months of chemotherapy with procarbazine, vincristine, cyclophosphamide, and CCNU, patients with extensive oat cell carcinoma of the lung were randomly allocated to receive 3000 rads of involved-field irradiation and further chemotherapy or to continue with chemotherapy only. In addition, all patients received 3000 rads of prophylactic whole-brain irradiation. The addition of involved-field radiation, as given in this trial, not only failed to improve survival but was unable to alter the pattern of sites of initial relapse. There were no cases of extension to the brain in 31 consecutive patients who received prophylactic whole-brain irradiation. This was in strong contrast to a preceding trial in which six cases of brain extension occurred among 19 patients who did not receive prophylactic whole-brain irradiation.

Aged↗

[Change of germs in several wards of hospital during the last twenty years under the therapy with antibiotics (author's transl)].

Statistical examinations concerning the change of germs and their resistance against antibiotics during the last twenty years were performed. The examinations dealed with the material of a bacteriological institute, the material of a department for nephrology and extracorporal dialysis, the material of a center for reanimation, and the material of an urological clinic.

Anti-Bacterial Agents↗

Influence of lysophosphatidylcholine on the metabolism of plasma lipoproteins.

Both low density lipoproteins and cellular membranes are known to have a high affinity for lysophosphatidylcholine. In this study lysophosphatidylcholine influenced the retention of lipoproteins by arterial tissue in vitro and the rate of disappearance of low density lipoproteins from the blood in vivo. Pieces of aorta from rabbits or rhesus monkeys were successively incubated for 90 min each in 2 or 3 solutions. After the last incubation the intima plus inner media was dissected from the remainder of the aorta for analysis. The second incubation always contained lipoproteins labeled with [3H]leucine. When lysophosphaticylcholine was included in the first but not in the second incubation fluid, the retention of low, or high density lipoproteins by the intima plus inner media increased. A subsequent incubation of the piece of artery in a fluid with trypsin or lysophosphatidylcholine caused a release of some of the lipoproteins. Lysophosphatidylcholine was bound simultaneously by plasma low density lipoproteins and vascular tissue in vitro and appeared to promote the association of the latter two components. When lysophosphatidylcholine equal to 2--10 times the usual total intravascular content was injected intravenously into control squirrel monkeys or rabbits, it was rapidly cleared from the blood. On the other hand, injected lysophosphatidylcholine persisted in the blood of hyperlipoproteinemic rabbits and was associated with the low density lipoproteins. In control animals, the injection of lysophosphatidylcholine was associated with an increase in the rate of removal of 125I-labelled low density lipoprotein from plasma and of its appearance in liver.

Animals↗

[Influence of pathogenesis of purulent meningitis on the prognosis (author's transl)].

1. Where a purulent meningitis develops in association with a cyclic infectious disease (e.g. meningococcal meningitis), the prognosis is to be designated good, provided that it is diagnosed early and that no Waterhouse-Friderichsen syndrome is present and that adequate treatment is carried out. 2. In transmitted meningitis after purulent processes in the head region (sinusitis, otitis media), in addition to early diagnosis and antibiotic therapy the suppurating focus must also be cleared out in time. 3. The worst prognosis is for a purulent meningitis associated with sepsis, because here there must not only be early recognition and treatment of the meningitis, but also the recognition and treatment of the septic focus.

Adult↗

The effects of dietary fat and cholesterol on the metabolism of plasma low density lipoprotein apoproteins in squirrel monkeys.

Low density lipoprotein apoproteins from squirrel monkeys (Saimiri sciureus) had characteristic 2-phase die-away curves in plasma. The kinetic constants were similar with three methods of labeling: in vitro with 125I by the iodine monochloride or the Bolton-Hunter methods or in vivo by the injection of [3H]-leucine into a donor animal. Dietary cholesterol and the type of dietary fat influenced the concentration of plasma cholesterol and low density lipoproteins. The fractional turnover of low density lipoprotein apoprotein was greaterin monkeys fed semipurified diets with safflower oil than in those on butter but was not influenced by dietary cholesterol. The total low density lipoprotein apoprotein turnover (the product of fractional turnover and plasma lipoprotein concentration) was highest in monkeys fed butter plus added cholesterol and lowest in those on safflower oil without cholesterol. Dietary safflower oil resulted in a smaller proportion of the total low density lipoprotein pool in the intravascular compartment than did butter, regardless of whether cholesterol was added.

Animals↗

[Change of pathogen in infections since 1958 (author's transl)].

Infections with proteus, pseudomonas, klebsiella and enterococci have increased significantly in the period of this report. The question of hospital hygiene, especially in intensive care wards, must therefore be given increased attention. Uncritical prophylaxis and treatment with antibiotics must be rejected. Attempts to improve the cellular and humoral defense of patients with reduced resistance would be worth while. To achieve progress, there must be a close co-operation between specialists in infection, hygienists, microbiologists, pharmacologists and immunologists. The activity of the specialists in infection is no longer exclusively confined to the isolated "epidemic ward", but includes advising clinicians in the various departments with regard to control of infection in the widest sense, and consequently a close co-operation with all clinical medical disciplines.

Adult↗

The accessory optic fiber system of the golden hamster with special reference to retinohypothalamic projection.

The hamster accessory optic fiber system has been investigated with the use of de Olmos-Ingram and Fink-Heimer silver methods following the production of unilateral ocular enucleation. It was found that this fiber system consists of both crossed and uncrossed inferior and superior fasciculi. The fibers of the inferior fasciculus (anterior accessory optic tract) run along the medial edge of the cerebral peduncle and terminate within the medial terminal nucleus of the accessory optic system. The fibers of the superior fasciculus (posterior accessory optic tract) leave the main optic tract, pass superficially over the medial geniculate nucleus and the cerebral peduncle; they synapse within the dorsal, the lateral and the medial terminal accessory optic nuclei. The presence of a retinohypothalamic tract could not be confirmed.

Animals↗

Microbial formation and degradation of dimethylamine.

Dimethylamine was formed from trimethylamine in soils of different pH values. The rate of disappearance of the secondary amine from soil was affected by pH and was markedly reduced under anaerobiosis. The accumulation of dimethylamine in cultures of Micrococcus sp. provided with trimethylamine depended on the nitrogen sources available to the bacterium but was not greatly influenced by the C-N ratio of the medium. Dimethylamine and nitrite accumulated in large amounts at pH 6.0 to 8.0 in cultures containing the tertiary amine and nitrate, but dimethylnitrosamine was apparently not produced.

Anaerobiosis↗

N-Nitrosamine formation by cultures of several microorganisms.

Of 38 pure cultures of microorganisms tested, only one, Pseudomonas stutzeri, was capable of forming dimethylnitrosamine from dimethylamine and nitrite during growth. Resting cells of P. stutzeri, Cryptococcus terreus, Escherichia coli, and Xanthomonas campestris formed dimethylnitrosamine, although no nitrosamine was found in growing cultures of the latter three organisms. No nitrosamine was produced by either growing cultures or resting-cell suspensions of Pseudomonas fragi or Proteus mirabilis. Boiled cells of P. stutzeri, but not those of C. terreus, E. coli, and X. campestris, formed dimethylnitrosamine, and this nitrosamine was also produced by extracts of E. coli cells at pH 5.0.

Bacteria↗

Head and neck cooling by air, water, or air plus water in hyperthermia.

The effects of air, water, and air plus water head cooling on thermoregulatory responses and human operator performance were studied in nonacclimatized, heat-exposed men. Forty chamber exposures (46 degrees C, 30 mm Hg water vapor pressure) were conducted under noncooled and the aforementioned subconditions of head cooling. Five subjects, exposed for 80 min, were monitored for mean skin and rectal temperatures, heart rate, sweat loss, and compensatory tracking performance. A modified Air Force helmet shell provided facial air ventilation (24 degrees C) at 8 cfm. Eight interconnected neoprene modules fastened beneath a helmet linear provided water cooling (20 degrees C at 0.9 l/min). Tracking performances was unchanged across conditions. Elevation of rectal temperature and heart rate, sweat loss, and Physiological Index of Strain were significantly reduced by each condition of head cooling. Air is as effective as water as a cooling agent. Air ventilation acts synergistically with water cooling in reducing physiological strain. Relative merits of each approach to head cooling, in an operational context, are discussed.

Adult↗

[Prognosis and treatment of idiopathic thrombocytopenic purpura in children].

The following conclusions can be drawn from the study of 55 cases of I.T.P. of childhood. 1. I.T.P. evolving more than 6 months must always be considered as chronic, the disease having in these cases few chances of recovery without splenectomy. After 6 months evolution, it is probably possible to establish a prognosis and a therapeutic approach with little risk of error. 2. Among the clinical and biological criteria noted at the onset of the disease, the intensity of thrombopenia alone is statistically different in acute and chronic I.T.P. Consequently, there are few criteria allowing the early recognition of evolution to chronic I.T.P. 3. The corticoids have no curative value in I.T.P. Prolonged corticotherapy is therefore useless in this disease. 4. As a palliative, the value of the corticoids can only be statisfactorily demonstrated in chronic I.T.P. Here it is certain in 6 cases on 16. 5. The value of corticoids for capillary resistance is evident, even in small doses. 6. Splenectomy must be considered in all cases of severe or corticodependant chronic I.T.P. Cure is obtained in most cases. 7. The contribution of immunosuppressive agents and in particular azathioprine, cannot be usefully assessed on the basis of the series studied. In the absence of decisive results, it would be worthwhile to evaluate this treatment by means of a greater number of clinical trials.

Acute Disease↗