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Biomedical subjects

A Hamberger

Publications and source records attributed to A Hamberger.

At least 163 records · Page 9Linked to original sources
PubMed1975

Tritiated methylmercury in the brain of squirrel monkeys.

Tritiated methylmercuty hydroxide (MeHgOH) with a specific activity of 306 curies/mol was synthesized by a Grignard reagent from tritiated methyl iodide with a yield of 70%. Tritiated MeHg was given to squirrel monkeys by stomach tube in weekly doses of 0.8 mg/kg. The animals were killed after one dose or six doses. The distribution of the substance in the brain was then studied by microautoradiography and by fractionation of brain tissue into cellular and subcellular fractions. Part of the MeHg in the brain is in a water-soluble form. Methylmercuty was found autoradiographically mainly in the neuropile of the cortex. At subtoxic doses (one dose), more protein-bound radioactivity was found in the glial fraction than in the neuronal fraction. At toxic dose (six doses), the protein-bound fraction of MeHg increased significantly (P less than .02) in the neurons relative to nontoxic dose (one dose). Methylmercury was demonstrated autoradiographically in damaged neurons but not in undamaged neurons.

Animals↗
PubMed1975

Amino acid incorporation into brain subcellular fractions in experimental allergic encephalomyelitis.

The in vitro protein synthetic capactiy of brain slices from guinea-pigs in the late stage (17-18 days post-induction) of experimental allergic encephalomyelitis was increased over that of Freund's adjuvant injected controls, as determined by the rate of (14C)-leucine incorporation into both tris-soluble and tris-insoluble proteins. All subcellular fractions prepared from incubated slices showed increased incorporation, with a crude nuclear fraction having the largest increase. Isolated brain mitochondria from EAE animals incorporated more amino acid into protein during the late stage of the disease, while isolated microsomes and "pH5 enzymes" show decreased amino acid incorporation compared with controls in the late stage of EAE. Polyacrylamide gel electrophoresis of acidic, soluble proteins isolated from (3H)-leucine labeled nuclear or synaptosomal fractions revealed that increases of incorporation were generalized, and not restricted to a few proteins.

Amino Acids↗
PubMed1975

Optimal treatment for the technically resectable squamous cell carcinoma of the supraglottic larynx.

The charts of 431 patients with squamous cell carcinoma of the supraglottic larynx observed at the M.D. Anderson Hospital between January, 1954, and June, 1971, were analyzed. This study is concerned with those patients who had a technically resectable lesion. Emphasis is directed to the analysis of the effectiveness of primary irradiation instead of partial laryngectomy for those lesions which are technically suitable for a partial resection and to define the groups of patients which are best treated by combining surgery and planned postoperative irradiation. One hundred forty-seven patients with T1 and T2 lesions, selected exophytic T3 lesions of the suprahyoid epiglottis received irradiation for their laryngeal lesion. A satisfactory control of the laryngeal disease has been obtained with preservation of a normal voice ranging from 88.5 percent for T1 lesions to 60 percent for T4 lesion. Comparing the groups of patients who had surgery alone or postoperative irradiation an NED rate of 63 percent was found in the latter group which is clearly superior to the 37 percent found in the surgery only group. There is no difference for the five-year NED rates, because the patients who had surgery and postoperative irradiation had more advanced neck disease which is a cause for distant metastases. The incidence of recurrences above the clavicles is clearly less in patients having had surgery and postoperative irradiation than in those who had surgery alone. Correlating in the two groups, surgery only and surgery followed by planned irradiation, the surgical staging of the neck metastases with recurrences above the clavicles within 24 months after treatment, it was found that the planned combined treatment has reduced the recurrence rate from 45 percent to 15 percent in the N2 and N3 patients. Postoperative irradiation should be given routinely after resection for all T4 lesions and for any T3 lesion which extends to the pharyngeal wall(s), vallecula, base of tongue, and pyriform sinus. Postoperative irradiation should also be given for any patient whose nodal classification is greater than N1. Irradiation should be given within six weeks (preferably three to four weeks) after the surgical procedure. To achieve this goal, the operation need only remove grossly detectable disease.

Aged↗
PubMed1975

Reasons for irradiation failure in squamous cell carcinoma of the larynx.

The reasons for irradiation failure in squamous cell carcinoma of the larynx can be: 1. Geographical miss because of undiagnosed extensions is the exception. Almost all of the recurrences were well within the treatment portals. 2. Specific extensions with an unfavorable tumor bed. Extension of disease into poorly vascularized structures and/or deep infiltration with fixation are causes of failure. 3. Low dose for the volume cancer. Higher doses delivered in longer treatment time are necessary for 90 percent control of bulky exophytic supraglottic lesions. 4. Techniques which do not assure daily coverage of the tumor. With carefully drawn and checked anatomical portals, geographical misses should be nonexistent. 5. Sigmoid response curve. There is an 85 percent control of the T1 glottic tumors. The control rate is 90 percent of the T1 and T2 supraglottic tumors, and the 10 percent failures have no obvious explanation except that the plateau of the sigmoid response curve has been reached. A negligible yield would be obtained by increasing doses which would not be justified because of concomitant increase in frequency and severity of complications and lessening of the quality of voice. 6. New cancer. Probably 25 percent of the so-called recurrences on the vocal cords are actually new primary lesions. The ultimate failure rates respectively are 2 percent for T1 lesions and 10 percent for T2 lesions after a rescue surgical procedure. All patients with T1 vocal cord lesions who did not experience a failure or a complication, have a normal voice. In the patients with T2 lesions in whom the cancer had completely replaced the cord(s), some hoarseness is present; but most of these lesions would have been suitable only for a total laryngectomy. In the 15 failures in T1 and T2 supraglottic lesions, surgery was not attempted in only three patients, one of whom was salvaged by re-irradiation. Following 12 laryngectomies there is only one definite failure and two patients died within two years NED locally. Except in the patients who had severe edema and/or necrosis, the voice has been normal or near normal. In patients with lesions of the suprahyoid epiglottis which had amputated the suprahyoid epiglottis swallowing difficulty has not developed.

Carcinoma, Squamous Cell↗
PubMed1975

Protein bound radioactivity in neuronal and glial fractions following intra-carotid 3H-leucine perfusion.

Brain proteins in one cerebral hemisphere were labeled by means of intracarotid perfusion with 3H-leucine by a 40 s pulse. Recirculating precursor contributed little to the protein bound radioactivity. This radioactivity reached a peak level 30 min after perfusion. Fractions enriched in neuronal perikarya and glial cells showed a similar time course of labeling, but the neuronal fraction demonstrated the highest level of protein bound radioactivity. Subcellular fractions from whole brain were studied by the same system. The highest protein bound radioactivity was observed in the nuclear and microsomal fractions. The brain entry of the precursor by means of a controlled intracarotid pulse of short duration offers particular advantages in short-term experiments since the systemic metabolism of the labeled precursor is largely avoided. The easily achieved high labeling of proteins facilitates assay of the radio-activities in different cellular and subcellular fractions and also allows analyses of relative turnover rates in electrophoretically separated proteins.

Animals↗