Hearing aids: design, mechanics, and characteristics.
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Acoustics↗
Biomedical subjects
C Gross
Publications and source records attributed to C Gross.
[Hypophosphatasia (author's transl)].
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Alkaline Phosphatase↗
[Pathological-anatomical aspects of organ-preserving surgical procedures for breast carcinomas (author's transl)].
This study is an attempt to evaluate the necessity of radical surgery based on the incidence of tumor remnants and lymphnode metastases in amputated breast after diagnostic excision. The material included 600 female patients, from 27-86 years old (mean age 58 years) examined at the Institute of Pathology University of Munich between 1969 and 1974. Retrospectively 36% of the specimen would have been free of tumor after en bloc resection, 21% simple mastectomy and 19% after simple mastectomy with additional axillary lymph-node disection. In fact, however, radical mastectomy was necessary in 25% for total removal of the tumor. As no methods for exact preoperative determination of tumor extension are yet known and as there is a high risk of recurrant tumor because of insufficient excision, organ-preserving surgical procedures still will be restricted to a few individual and selected cases of breast carcinoma presuming the patients consent.
Adult↗
Mutation affecting thermostability of sigma subunit of Escherichia coli RNA polymerase lies near the dnaG locus at about 66 min on the E. coli genetic map.
The Escherichia coli strain, ts-rnp5, originally described in 1975 by G. D. Burdick and H. Berger, is shown to possess an RNA polymerase (RNA nucleotidyltransferase) sigma subunit with an activity 4--6 times less thermostable at 45 degrees than sigma from wild-type strains. This defect remains associated with the sigma polypeptide through a variety of purification stages, including renaturation of sigma after its elution from sodium dodecyl sulfate/polyacrylamide gels. The mutation responsible for decreased thermostability of sigma, called rpoD1, cotransduces with dnaG and therefore is located at about 66 min of the E. coli genetic map.
Chromosome Mapping↗
[Electrophysiologic aspects of the effects of etomidate in man].
Recordings were electroencephalographical (EEG with spectral analysis), polygraphical (EMG, EKG, breathing). Visual and Auditory Cerebral Evoked Responses were also recorded. The depth of narcosis was quantified upon EEG data. The reactivity during the narcosis and the mechanisms of action of Etomidate on the "non specific structures" are discussed. Cautions should be taken with the use of tomidate in anesthesiology with epileptic and arteriopathic patients.
Adult↗
Angiotensin blockade in renovascular hypertension: a controlled, prospective study.
Saralasin, a specific competitive inhibitor of angiotensin II, was administered in a controlled, prospective study designed to test the hypothesis that this agent is a useful tool for the detection of renovascular hypertension. 13 patients, 11 with renovascular hypertension and 2 with high-renin essential hypertension, showed a gross, readily apparent decrease in blood pressure after receiving saralasin. 8 patients with essential hypertension and normal or low renin levels exhibited no depressor response to the drug. In the patients with renovascular hypertension, blood pressure response during angiotensin blockade compared favourably with renal vein renin determinations as a predictor of operative results. Because saralasin testing has resulted in few if any falsely positive or negative results when considered as a diagnostic procedure for renin-mediated hypertension, and because it is safe, it may become an ideal initial screening procedure. The saralasin test (either bolus injection or sustained infusion) is completely valid only if the patient is mildly salt-depleted, is not taking other antihypertensive medication, and is genuinely hypertensive at the time of the test.
Adult↗
Biosynthesis of Escherichia coli RNA polymerase subunits upon release of rifampicin inhibition.
Upon release of rifampicin inhibition of Escherichia coli cells, the initiation of transcription will resume. The sequential resumption of the synthesis of proteins after release of rifampicin inhibition reflects the genetic order and size of the corresponding transcriptional units. We have used this approach to analyze whether the genes for alpha and sigma are on the same transcriptional unit as the genes for beta and beta', employing a method, which allowed us to measure the amounts of RNA polymerase subunits, alpha, beta, beta' and sigma in crude extracts. We have found that the alpha and sigma subunits are synthesized concurrently with the beta subunit in the rifampicin restart experiment, which suggests that the genes for alpha and sigma belongs to different transcriptional units.
Chromosome Mapping↗
Rapid micromethod for the purification of Escherichia coli ribonucleic acid polymerase and the preparation of bacterial extracts active in ribonucleic acid synthesis.
A rapid micromethod is described for the preparation of nucleic acid-free extracts from Escherichia coli that involves precipitation with polyethylene glycol. Extracts can be prepared from growing cells in 75 min by three short, low-speed centrifugations. The extract did not inhibit added purified ribonucleic acid (RNA) polymerase, suggesting that major inhibitors of RNA synthesis had been removed. This extract should be ideal for assessing the properties of mutant RNA polymerases. The rapid chromatography of the extracts with step elution from deoxyribonucleic acid- and diethylaminoethyl-cellulose columns resulted in high yields of substantially pure RNA polymerase. We used this technique to purify 35S-labeled RNA polymerase. This system should find application for the purification of small quantities of other bacterial RNA polymerases that share the general chromatographic properties of E. coli RNA polymerase.
Chemical Precipitation↗
Cysteine and methionine content of the Escherichia coli ribonucleic acid polymerase subunits.
We describe a procedure that allows cysteine and methionine content to be determined on microgram amounts of partially purified protein. The only requirements are that the protein can be obtained as a pure band after electrophoresis on a polyacrylamide gel and that some data on amino acid content be available. This method involves double labeling by growing bacterial cells with [3H]leucine and [35S]SO4 and determining the ratio of these radioisotopes incorporated into the ribonucleic acid polymerase subunits. The relative specific activities of [3H]leucine and [35S]cysteine and methionine are determined from the ratio of these isotopes incorporated into beta-galactosidase, the leucine, cysteine, and methionine contents of which are known. We have used this procedure to determine the sulfur content of the subunits of Escherichia coli ribonucleic acid polymerase. These new data are necessary to quantitate the rates of synthesis of these subunits by in vivo labeling with [35S]SO4.
Cysteine↗
The effectiveness of drug education programs: a critical review.
Twenty-seven studies were reviewed to determine whether school-based drug abuse prevention efforts have succeeded. Most of the studies reviewed either did not examine program impact on actual drug using behavior or were not designed with a degree of scientific rigor sufficient to warrant acceptance of their findings as valid. Those studies leading to reliable results regarding program effect on drug use were contradictory in their conclusions. In view of the possibility that educational efforts aimed at drug abuse prevention may be counterproductive, it is suggested that school-based programs henceforward be designed and conducted as experiments with controlled manipulation of relevant variables.
Adolescent↗
Know your president.
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Administrative Personnel↗
Ventricular fibrillation caused by arsenic poisoning.
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Anti-Arrhythmia Agents↗
Note on the nitrogen content of certain proteins.
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Journal Article↗
Nursing home resuscitation policies and practices for residents without DNR orders.
The purpose of this study was to explore the policies and practices of nursing homes with respect to the resuscitation of residents who do not have a do-not-resuscitate (DNR) order. Responses from a survey of 36 facilities revealed that most residents had DNR orders and most facilities were capable of providing basic cardiopulmonary resuscitation (CPR). Less than 30% had performed CPR in the past 6 months, and 22.8% had no written CPR policies. More facilities required CPR in witnessed arrests of non-DNR residents (79.3%) than in unwitnessed arrests (24%). Methods for identifying CPR status need improvement to enable accurate identification and prompt resuscitation of residents who want CPR.
Advance Directives↗
[Cerebral blood flow and metabolism under "diazanalgesia" (author's transl)].
"Diazanalgesia" employs the combination diazepam + fentanyl. Its effects were studied on regional cerebral blood flow and oxygen metabolism in 8 normal subjects, who were examined angiographically. During diazanalgesia, cortical blood flow falls by 56 p. 100. The mean hemispheric flow calculated over 10 min falls by 34 p. 100. Cerebral O2 consumption (VcO2) falls by 34 p. 100. However, large individual variations are found which suggests that the fall in blood flow is not due solely to the decrease in O2 metabolism. The decreases in flow are not proportional to the amount fentanyl, and there is no direct relation between falls in VcO2 and amount of fentanyl. Cerebral vaso-reactivity to CO2 persists but is reduced under diazanalgesia compared with the waking state.
Anesthesia↗
Erythrocyte Na+,K+ cotransport and Na+,K+ pump in black and caucasian hypertensive patients.
Alterations in red blood cell (RBC) Na+,K+ pump and in Na+,K+ cotransport (CoT) have been described in essential hypertension (EH). We examined pump and CoT in 50 normotensive (NT) subjects and 58 EH subjects subdivided by race and family history of hypertension (+ FH). RBCs were preloaded with Na+ to obtain intracellular levels of 25 mM/liter cells by using the p-chloromercuribenzene sulfonic acid (pCMBS) method. Na+ and K+ efflux rates into a magnesium-sucrose medium were quantitated in the presence of ouabain and ouabain plus furosemide to define pump and CoT activity respectively. Mean intracellular Na+ content was higher (p less than 0.05) in black NT and HT subjects compared to Caucasians. Mean RBC CoT was lower in black EH compared to NT and compared to Caucasian NT and HT subjects. Conversely, Caucasian HT patients had higher mean CoT than NT subjects. Subdivision into + FH revealed very little effect of + FH on CoT in black NT and HT subjects. In Caucasian NT and HT subjects with + FH, mean CoT was significantly reduced (less than 0.3 mM/liter cells/hr) compared to those without + FH. A subgroup of Caucasian EH subjects displayed high CoT (greater than 0.6 mM/liter cells/hr); a + FH had little impact on the high CoT group. There was no correlation between RBC CoT activity and age, sex, severity of hypertension, urinary sodium excretion, and plasma aldosterone. There was a positive correlation (r = + 0.47; p less than 0.01) between CoT and upright plasma renin activity.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗