Search PubMed⌕ Search

Biomedical subjects

K Weiss

Publications and source records attributed to K Weiss.

At least 145 records · Page 8Linked to original sources
PubMed1980

[Value of sputum cytology in preoperative diagnosis of bronchial carcinoma].

Of 492 in patients with primary lung cancer, pathological proof of diagnosis after thoracotomy was obtained by sputum cytology in 53,87%. Better results were obtained in patients over the age of 70 years and even in peripheral lung tumors. The results were analyzed according to tumor size, localization and malignant cell type. The prognosis of patients with positive and negative cytological specimens are compared.

Adult↗
PubMed1980

Indications for surgical treatment of occlusive disease of the afferent cerebral arteries.

Indications for reconstruction operations in the region of branches of the arch of the aorta must be based on a comprehensive evaluation of the neurological and angiographic finding and the general condition of the patient. This ensues from the experience assembled in more than 800 operations performed since 1959. To evaluate the surgical risk, a scoring system was elaborated which evaluates the partial risks of each basic aspect of indication. Based on the sum of partial risks, four grades were defined. Patients who meet the prerequisites for surgical risk I and II (mainly with transient ischaemic attacks and asymptomatic stenoses of the internal carotid artery) can be indicated, with regard to hitherto assembled results, unequivocally for reconstructions. In grade IV risk it is essential to consider whether the risk of the natural course is greater than the risk of the operation and whether the affection of the afferent cerebral artery is the main limiting factor. The authors discuss contemporary views on indications of acute reconstructions of stenoses and occlusions of the internal carotid artery based on the neurological and angiographic factor and the time factor. From the evaluation of results of 92 urgent operations on account of recent or imminent symptoms of cerebral ischaemia ensues that for the result the grade and dynamics of the ischaemic cerebral affection at the time of the operation are decisive.

Arteriosclerosis↗
PubMed1979

Effects of 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide, 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea, and L-phenylalanine mustard on B16, Cloudman S91, and Harding-Passey mouse melanomas.

The effects of 5-(3,3-Dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC), 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (MeCCNU), and L-phenylalanine mustard (L-PAM) have been compared by using three i.p. transplanted mouse melanomas: the B16 melanoma in C57BL/6 mice; the Harding-Passey (HP) malanoma in BALB/c X DBA/2F1 (hereafter called CD2F1) mice; and the Cloudman S91 melanoma in DBA/2 mice. HP melanoma responds well to all three drugs. S91 responds only to L-PAM and MeCCNU. DTIC may accelerate death in mice bearing this tumor. B16 responds well to L-PAM and moderately well to MeCCNU and to multiple injections of DTIC. The best response to DTIC and MeCCNU is given by HP, while the best response to L-PAM is given by S91. Tumor cell-doubling times were found to be 1.5 days for B16, 2 DAYS FOR HP, and 3 days for S91. HP would seem to be the most responsive malanmoma with respect to the 3 agents studied. This may be due to an interaction between the chemotherapeutic agents and the host immune response, since the HP tumor arose in a noninbred mouse and is thus nonsyngeneic with the CD2F1 host. All three tumors appear to be interesting biological models for studying drug combinations and combined therapeutic modalities against melanoma.

Animals↗
PubMed1978

Radiation exposure and recognition of electron microscopic images of protamine at high resolution.

The effect of radiation exposure on visual recognition of individual macromolecules of the protein protamine was examined using high resolution electron microscopy in scanning transmission, fixed beam transmission, dark field and bright field, and recording of images on plates or via video imaging systems including image intensifiers and digital image storage. Loss of recognition of protamine, including its 5 A substructure, followed approximately three-hit kinetics with a Do on the exponential portion of the curve of about 470 e/A2. In spite of the inevitable chemical damage at high doses, virtually all molecules in orientations that exhibited the characteristic protamine structure could still be recognized in dark field scanning transmission or fixed beam bright field at 100-200 e/A2. Recognition fell from 30 to 6% when doses were increased from 1000 to 2000 e/A2 in fixed beam dark field. Exposure rates, varied over seven orders of magnitude from 0.15 e/A2-s to 3 X 10(6) e/A2-s, had no effect at all on the recognition of structures.

Animals↗
PubMed1976

Water regulation by a presumptive hormone contained in identified neurosecretory cell R15 of Aplysia.

Injection of an homogenate of identified neuron R15 into the hemocele of Aplysia produced a weight increase of 3-10% within 90 min. Control injections of several other identified neurons or of seawater, were ineffective. The weight increase occurred even when the animals were maintained in 5% hyperosmotic seawater. The activity of the R15 homogenate was retained after acidification to pH 2 and heating to 100 degrees C; but activity was destroyed by proteolytic digestion with Pronase. Dialysis in cellulose dialysis tubing resulted in a significant loss of aion on Sephadex G-50 (nominal exclusion limits 1,500-30,000 daltons), activity was present in the partially included volumes, but was absent in the totally excluded or totally included volumes. The data support the notion that R15 contains one or more hormones involved in ionic regulation or water balance. The results of bioassays of R15 extracts subjected to different treatments are consistent with the hypothesis that activity is due to one or more stable polypeptides of relatively low molecular weight.

Animals↗