Acoustic reflex threshold and loudness discomfort level: relationships in children with profound hearing losses

Acoustic reflex thresholds (ART) and loudness discomfort levels (LDL) were obtained from 51 ears of 34 deaf children using broad band noise and pure tones. Both thresholds and levels were recorded using the psychophysical method of tracking. Results indicate that the relationship between ART and LDL is at variance with similar data for normal hearing individuals. Specifically, in over 39% of these deaf children LDL was obtained at a lower intensity than ART. Implications for hearing aid fitting with deaf children are discussed.     

Anorexia nervosa in children: a follow-up study

Thirty children seen between 1954 and 1970 with the diagnosis of anorexia nervosa were contacted between five and twenty years after initial treatment. Patients outcomes in terms of education, weight in adulthood, medical problems, marriage, psychiatric treatment, and recurrence of anorexia were surveyed. Results corroborate those of earlier studies suggesting that adjustment in adulthood is related to personality type.     

Analysis of theoretical behavior of a proposed zero-order drug delivery system

An analysis of the theoretical behavior of a proposed zero-order drug delivery system is presented. Equations describing drug release with time are developed using a physically realistic model. The theory agrees well with experimental data and indicates that drug release from the device is nearly, although not rigorously, zero order.     

Influence of glucagon replacement on the hyperglycemic and hyperketonemic response to prolonged somatostatin infusion in normal man

Somatostatin was infused for 6 h into seven normal subjects with and without a replacement dose of glucagon. The addition of glucagon to somatostatin resulted in a 30-40% rise in plasma glucagon, whereas plasma insulin declined by 40-50% in both treatment groups. Plasma glucose and glucose production initially increased 2-fold with glucagon replacement, and subsequently declined by 2-3 h to levels comparable to those observed with somatostatin alone. After 6 h plasma glucose and glucose kinetics were no different whether or not glucagon was present. The rise in blood ketones after somatostatin was not exaggerated by glucagon replacement. We conclude that glucagon lack is not a modifying factor in the late hyperglycemic and hyperketonemic response to prolonged infusions of somatostatin.     

Renal cortical blood flow distribution in obstructive nephropathy in rats

To examine the role of intrarenal hemodynamics in in obstructive nephropathy, we determined cortical blood flow distribution (CBFD) in rats with bilateral ureteral occlusion (BUO) and unilateral ureteral occlusion (UUO) during and after release of obstruction. Prior to release of obstruction of 24 hours' duration, we found that outer cortical perfusion decreased by 20+/-5% in both BUO and UUO rats. Furthermore, one hour after release of BUO, there was rapid normalization of CBFD associated with a modest return of glomerular filtration rate (GFR), an almost complete return of renal blood flow (RBF), and a marked postobstructive diuresis. In contrast, after release of UUO, we observed that outer cortical perfusion remained decreased by 21+/-31%, both GFR and RBF remained markedly depressed, and no diuresis occurred. These data demonstrate (1) marked ischemia of the outer cortex in both BUO and UUO during obstruction, (2) a rapid return of CBFD to a normal pattern after release of BUO, but (3) persistent outer cortical ischemia following release of UUO.     

Sources and dissemination of contamination in material handling operations

To assess the potential risks to personnel preparing feed for carcinogen bioassay research, a tracer was mixed with a meal diet to yield 10 kg batches of 100, 3,000 and 5,890 ppm. Wipe samples were obtained from horizontal and vertical surfaces, equipment and personnel before operations began, after they were completed, and following clean-up. Total and respirable suspended particulate matter samples were obtained. All operations led to contamination of clothing and equipment; cleaning did not remove all contamination. These results, obtained in a well controlled environment in which trained and well protected personnel were working, suggest that a higher level of process control may be required for adequate protection of personnel performing material handling operations with known or suspected carcinogens.     

The subunit structure of bovine brain 14-3-2

Two aspects of the subunit structure of the bovine brain specific protein 14-3-2 have been examined. On the one hand, native 14-3-2 has been separated into two fractions by hydroxylapatite chromatography. One eluted at the same position when chromatographed on the same column, while the other redistributed into the same two fractions again. Amino acid analysis of these two forms of 14-3-2 gave results that were not significantly different under the condition of analysis. Furthermore, when each peak was subjected to cyanogen bromide cleavage, very similar elution profiles of the resultant fragments were obtained. The two pools also cross-reacted with antiserum to 14-3-2. Reaction of purified 14-3-2 with dimethylsuberimidate caused the formation of covalently bound protein units of 100,000 molecular weight when measured by sodium dodecyl sulfate polyacrylamide gel electrophoresis, as opposed to the 50,000 minimal molecular weight normally detected. On the other hand, analysis of the soluble tryptic peptides of S-[14C]carboxymethyl 14-3-2 yielded only three distinct radioactive peptides, each with one residue of S-carboxymethylcysteine whereas 8 are expected on the basis of the amino acid composition of the 50,000 molecular weight polypeptide chains. Thermolysin digestion of a similarly modified 14-3-2 preparation yielded all of the radioactivity in 5 S-carboxymethylcysteine-containing peptides. The partial amino acid sequence of these peptides indicates that they represent 4 unique areas of the polypeptide chain. Since 8 such peptides were expected, that is, double the number found, the minimum structural unit of the protein must be of 25,000 molecular weight. The results of these experiments do not permit distinction between a duplication of the structure within a single polypeptide chain or the alternate possibility of two polypeptide chains bound by unusually strong non-covalent bonds. These results suggest that 14-3-2 is a covalently linked dimer of 25,000 mol.wt. units that can aggregate to form larger species of 100,000 mol.wt. and higher.     

Quinuclidine chemistry: autocondensation reactions of 3-quinuclidinone

During the synthesis of 3-hydroxy-3-ethinylquinuclidine (I), two additional products were isolated and identified as (E)-3-[2-(3-oxoquinuclidine)]quinuclidylidene (III) and (E)-3-[2-(3-hydroxy-3-ethinylquinuclidine)]quinuclidylidene (V). The base-catalyzed autocondensation of 3-quinuclidinone resulted in the alpha,beta-unsaturated ketone dimer (III) as a single isomer. The geometric configuration was deduced by examination of the NMR spectra of the methyl iodide salt. Compound V was thus the result of attack on the carbonyl carbon of III by the acetylide anion. The isolation and identification of these compounds clarified the reported differences in the physical properties of I and its analogs.