The correlation of the vasopressin- and oxytocin-producing activities of different nuclei in the hypothalamo-hypophyseal neurosecretory system]

Radioiodine long has proven to be a safe and effective treatment for thyroid disease. Nonetheless, persisting concerns regarding radiogenic stochastic risks (e.g., carcinogenesis) to patients, their families, and the general public have led regulators to establish criteria for release of 131I-containing patients from medical confinement, with limits ranging from as low as 2 mCi in some parts of Europe to as high as 30 mCi in the United States. To optimize clinical efficacy and cost-effectiveness of 131I therapy, such regulations should be based on logical dosimetric considerations. The thyroidal absorbed dose, proportional to maximum uptake and effective half-life and inversely proportional to mass, is typically approximately 1,500 rad/mCi of 131I administered to a euthyroid adult (based on a thyroid maximum uptake of 25%, effective half-life equivalent to the physical half-life of 131I (8.04 days), and mass of 20 g). As thyroid uptake increases from 0% to 100%, extrathyroidal absorbed doses range from a minimum of 0.15 to 0.5 rad/mCi for breast and gonads to a maximum of 1.5 to 2 rad/mCi for stomach and salivary glands; the absorbed doses of the urinary bladder wall, in contrast, decrease with increasing thyroid uptake, from 2 to 0.6 rad/mCi. In hyperthyroid patients (approximately 15%) with a small iodine pool (so-called small patients), the short effective half-life of radioiodine in the thyroid and high serum concentrations of long-lived protein-bound 131I result in a standard 7,000-rad absorbed dose for treatment of Graves' disease requiring an administered activity of 28 mCi of 131I and yielding a prohibitively high blood absorbed dose of 150 rad. Importantly, once the fetal thyroid begins to function and accumulate radioiodine at a gestational age of 10-12 weeks, fetal thyroid absorbed doses as large as 5,000 rad/mCi of 131I administered to the mother can result. Thus, pregnancy is an absolute contraindication to administration of 131I because of the risk of radiogenic cretinism. Based on actual measurements of thyroid activity and of external absorbed dose, the total thyroid and mean extrathyroidal absorbed doses to adult family members from immediately released 131I-treated patients are approximately 0.01 and approximately 0.02 rad/mCi administered, respectively, yielding an effective dose of approximately 0.02 rem/mCi. A maximum permissible effective dose of 0.5 rem for adults therefore is consistent with a release criterion of 30 mCi of retained 131I. Lower-activity release criteria therefore may be unnecessarily restrictive.     

Dimerization of recombinant horseradish peroxidase in a reversed micellar system

Recombinant horseradish peroxidase reactivated from E. coli inclusion bodies was studied in a reversed micellar system of AOT in octane. The ability of the recombinant enzyme, in contrast to native horseradish peroxidase, to form a dimeric structure was found. The existence of the dimer was proved by results of sedimentation analysis. Dimer/monomer ratio in the enzyme-containing micelles and dimer catalytic activity were found to depend on the substrate used (pyrogallol, guaiacol, o-dianisidine, o-phenylenediamine). Computer modelling was used to describe possible structures of the dimeric recombinant horseradish peroxidase.     

Do advanced cardiac life support drugs increase resuscitation rates from in-hospital cardiac arrest? The OTAC Study Group

STUDY OBJECTIVE: The benefit of Advanced Cardiac Life Support (ACLS) medications during cardiac resuscitation is uncertain. The objective of this study was to determine whether the use of these medications increased resuscitation from in-hospital cardiac arrest. METHODS: A prospective cohort of patients undergoing cardiac arrest in 1 of 5 academic hospitals was studied. Patient and arrest factors related to resuscitation outcome were recorded. We determined the association of the administration of ACLS drugs (epinephrine, atropine, bicarbonate, calcium, lidocaine, and bretylium) with survival at 1 hour after resuscitation. RESULTS: Seven hundred seventy-three patients underwent cardiac resuscitation, with 269 (34. 8%) surviving for 1 hour. Use of epinephrine, atropine, bicarbonate, calcium, and lidocaine was associated with a decreased chance of successful resuscitation (P <.001 for all except lidocaine, P <.01). While controlling for significant patient factors (age, gender, and previous cardiac or respiratory disease) and arrest factors (initial cardiac rhythm, and cause of arrest), multivariate logistic regression demonstrated a significant association between unsuccessful resuscitation and the use of epinephrine (odds ratio . 08 [95% confidence interval .04-.14]), atropine (.24 [.17-.35]), bicarbonate (.31 [.21-.44]), calcium (.32 [.18-.55]), and lidocaine (.48 [.33-.71]). Drug effects did not improve when patients were grouped by their initial cardiac rhythm. Cox proportional hazards models that controlled for significant confounders demonstrated that survivors were significantly less likely to receive epinephrine (P <. 001) or atropine (P <.001) throughout the arrest. CONCLUSION: We found no association between standard ACLS medications and improved resuscitation from in-hospital cardiac arrest. Randomized clinical trials are needed to determine whether other therapies can improve resuscitation from cardiac arrest when compared with the presently used ACLS drugs.     

The glycerylphosphorylcholine content of the rat epididymis after injecting alpha-chlorohydrin and ligating the vasa efferentia

There are few reports which discussed normal RI-cisternography in infancy and childhood. The cisternograms of the children between 2 months and 13 year-old were classified under a criteria into three groups; 17 normal cases, 135 borderline cases and 77 abnormal cases. The former two groups were compared with each other and characteristic findings of RI-cisternography in infants and children were appreciated clinically. And we attempted to establish normal RI-cisternography. The characteristic findings are: 1) When the images of cisterna magna is dilated, it can not be concluded directly that the abnormality of posterior fossa are suspected. 2) The bulk flow of CSF in infancy and childhood flows faster in intracranial subarachnoid space as well as intraspinal than the flow of adults. 3) Early ventricular reflux seems to be not valuable clinically. But we would like to emphasize that the incidence of these findings are variable as children grow older. The mechanism of this phenomenon needs further investigation.     

Pulmonary cytopathology of former asbestos workers. Report of the first year

Five hundred fifty-four workers, 84% of whom are chronic cigarette smokers, have been examined during the past year with emphasis on the role of sputum cytopathology in the early detection and diagnosis of lung cancer. Of the 554, 232 (42%) have shown squamous metaplasia, 44 (8%), mild to moderate atypias, 18 (3.2%), severe atypias, and two (0.4%), squamous carcinoma. Both of the carcinomas were in x-ray negative, cytopathology-positive elderly cigarette smokers. Ferruginous bodies have been found in the sputa of 187 (33%) workers. Ferruginous bodies in the sputum do not appear to be a marker for severe atypias; rather, their presence correlates best with duration and extent of industrial exposure to asbestos.     

Experimental intravitreal gentamicin

Rabbits received intravitreal injections of gentamicin and indirect ophthalmoscopy, electroretinography, and histopathology determined relative toxicity. An intravitreal dose of 0.1 to 0.2 mg of commercially available gentamicin was well tolerated in the rabbit eye. A dosage of 0.4 mg or higher consistently produced significant ocular toxicity as evidenced by extinction of the electroretinogram, gross fundus changes, and histopathologic alterations.     

Role of mitochondrial membrane potential in the regulation of murine erythroleukemia cell differentiation

The level of cytoplasmic calcium ions appears to be important in the control of murine erythroleukemia (MEL) cell differentiation. Our interest in this study focuses on the relationship between the regulation of calcium concentration and differentiation. We used the fluorescent membrane probe DiOC6 to examine the relationship between MEL cell mitochondria and changes in cytoplasmic calcium levels occurring at the initiation of commitment. Fluorescence microscopy reveals the selective association of DiOC6 with MEL cell mitochondria, where an enhanced fluorescence is observed. Treatment of cells with dimethylsulfoxide (DMSO) or other inducers causes a decrease in mitochondria-associated fluorescence levels that occurs with the initiation of commitment. A decrease in DiOC6 fluorescence is caused by agents that reduce mitochondrial membrane potential, but is only slightly affected by agents that alter plasma membrane potential. Amiloride and EGTA, agents that prevent commitment and inhibit calcium uptake, also prevent the decrease in DiOC6 uptake caused by DMSO. The effect of DMSO on MEL cell mitochondria is mimicked by FCCP, a proton ionophore that dissipates mitochondrial membrane potential. FCCP also caused MEL cell mitochondria to release calcium into the cytoplasm. When MEL cells are treated with DMSO plus FCCP, commitment is initiated without the lag period observed when cells are treated with DMSO alone. These results are consistent with the hypothesis that mitochondrial transmembrane potential is important in the regulation of cytoplasmic calcium levels at the time of commitment of MEL cells to terminal differentiation.