Ultrastructural evidence for bouton proliferation in the partially deafferented dentate gyrus of the adult rat

A quantitative morphological study of the changes in the dentate gyrus molecular layer in response to the removal of perforant path afferents was made utilizing electron microscopic techniques. Alterations in 1. the population of remaining afferents, 2. glial cells, and 3. granule cell dendrites are reported. The major observation was an increase in intact bouton density in the region of denervation which began at 5 days post-lesion and continued through 11 days post-lesion, the longest post-lesion survival time studied.     

Isolation of a spontaneous CHO amino acid transport mutant by a combination of tritium suicide and replica plating

A spontaneous transport mutant of Chinese hamster ovary cells, CHY-1, was isolated by a combination of [3H]proline suicide and replica plating. The mutant took up less tritium than the parent, resulting in a lower killing rate during storage. Transport by four separate amino acid transport systems (A, ASC, L, Ly+) was examined. The CHY-1 mutant exhibited normal uptake via the ASC, L, and Ly+ systems. By contrast, uptake of the most specific substrate of the A system, 2-(methylamino)-isobutyric acid, was significantly reduced at low, but not high, concentrations, due to a 3.5-fold increase in Km and a 1.5-fold increase in Vmax. Taken together, these data suggest that the CHY-1 mutation may be in the structural gene coding for the A transport protein. The tritium suicide procedure is discussed, and general equations are derived to predict the maximum storage time for the survival of one mutant cell and the optimum size of the cell population for maximum mutant enrichment.     

Seasonal variation in spontaneous abortions

Using a national sample of hospital discharges, we found identical seasonal patterns for spontaneous abortions and conceptions but no significant seasonal variation in the rate of spontaneous abortions per 1,000 conceptions. The differences between our findings and those of previous investigators of spontaneous abortion may reflect our more comprehensive definition of spontaneous abortion, our more complete estimate of the monthly number of conceptions, and our more rigorous statistical analysis. The periodic regression analysis (PRA) reported in our study may be useful in other studies that monitor short-term trends.     

Automatic monitoring of deposition conditions during rf sputtering of dielectric materials

Modern optics often require dielectric thin films of precisely controlled optical indices. One method of producing such films is by rf sputtering at extremely low deposition rates (～0·1 μh^?1). Thermal and plasma instabilities occur during the deposition process (often > 10 h duration) and the sputtering system therefore requires continuous monitoring to ensure appropriate corrective action.The objective of this paper is to examine the technology involved in developing supervision circuitry to monitor the parameters of a conventional commercially available rf sputtering system employed in the fabrication of high optical quality dielectric films for integrated-optics applications. The techniques used have overcome the difficulties of operating analogue circuitry in a high rf noise environment.A novel reflection-interferometer, enabling continuous monitoring of sputtered film thickness in a close spaced target-substrate system, was developed. The design has been shown to possess enhanced alignment tolerance, particularly for high refractive index films.     

Persistent and recurrent sporadic primary hyperparathyroidism: histopathology, complications, and results of reoperation

BACKGROUND: Our purpose was to analyze the causes of persistent and recurrent sporadic primary hyperparathyroidism (PD and RD). METHODS: The histopathology, complications, and results of reoperation were studied. Five hundred sixty-eight patients with primary hyperparathyroidism were operated on initially by one surgeon and underwent follow-up examination for 3.7 +/- 3.8 years. During the operation, all parathyroids were sought and confirmed by biopsy. Enlarged glands were resected, and subtotal parathyroidectomy was done for multiglandular disease (hyperplasia). RESULTS: The cure rate after the initial surgical procedure was 96.4%, PD = 2.8% (16 of 568). At reoperation (10 of 16), nine of 10 were cured (90%) (two adenomas, six hyperplasias, one lung carcinoma). RD was documented (at years 4, 4, 10, 15, 16) in five (0.9%) patients, one with parathyroid carcinoma and four with hyperplasia. Thirty-five patients with PD and two patients with RD were referred for reoperation: 17 with adenomas (eight mediastinal) and 18 with hyperplasias (one mediastinal gland). Preoperative calcium level was higher for PD (12.57 mg/dl) and RD (13.89 mg/dl) versus all cases (12.19 mg/dl) (p < 0.03 and p < 0.0005, respectively). After reoperation, normocalcemia was achieved in 47 (92.%) of 51 patients with PD or RD. Transient hypocalcemia occurred in 22% of patients (permanent, 2.0%) and transient hoarseness in 2.0% of patients (no permanent nerve damage). Permanent hypocalcemia and nerve damage after 568 initial operations were 0% and 0%, respectively. Two perioperative deaths occurred. CONCLUSIONS: We conclude that inadequate neck exploration or resection of hyperplastic tissue accounts for most cases of PD and RD. Optimal results necessitate intraoperative identification of all parathyroids whenever possible, with minimal morbidity.     

Preparation, isolation, analysis, and characterization of 3-benzo[a]pyrenyl-beta-D-glucopyranosiduronic acid: a metabolite of 3-hydroxybenzo[a]pyrene with potentially high carcinogenic activity

The aglycone, 3-hydroxybenzo[a]pyrene, was metabolized to 3-benzo[a]pyrenyl-beta-D-glucopyranosiduronic acid in the presence of uridine 5'-diphosphoglucuronic acid and rabbit liver microsomes. The course of the biosynthetic reaction was followed by fluorimetry and reverse-phase, paired-ion high pressure liquid chromatography (HPLC). Also, the HPLC system was used to analyze for glucuronide and 3-hydroxybenzo[a]pyrene during the isolation procedure. The existence of a glucuronide of 3-hydroxybenzo[a]pyrene was determined by radiotracer and enzymic techniques, utilizing the HPLC system. Field desorption and direct inlet mass spectral techniques were used to characterize the 3-hydroxybenzo[a]pyrene glucuronide.