Midbrain periaqueductal gray neurons with substance P- or enkephalin-like immunoreactivity send projection fibers to the nucleus accumbens in the rat

Employing a combination of retrograde tracing and immunocytochemistry, midbrain periaqueductal gray (PAG) neurons with substance P- or leucine-enkephalin-like immunoreactivity in the rat were found to send projection fibers to the nucleus accumbens bilaterally with an ipsilateral dominance. These neurons were most frequently seen in the ventrolateral and ventral parts of the medial PAG subdivisions at all rostrocaudal levels of PAG.

Extended asymptotic theory of unstable resonator modes

The modes in an unstable resonator can be computed within the limit of a large Fresnel number using the asymptotic expansion of the diffraction integral, as shown by Horwitz, Butts, and Avizonis. The expansion is not valid for the points of interest around or beyond the shadow boundary of the output light. We use a better numerical representation, which extends the regions of use. The comparison of several cases with earlier work shows that the asymptotic theory can be successfully applied for all parameters without restrictions.

[Intermittent negative pressure aspiration in the treatment of chronic pneumothorax with report of 35 cases]

The authors reported 35 cases of chronic pneumothorax who failed to the treatment with bed rest, gas aspiration from cavity and simple closed drainage. In order to re-expand the collapsed lung, intermittent negative pressure aspiration and periodic injection of drugs into pleural cavity was performed with good results. During and after the negative pressure aspiration. There was no severe side effect such as hypotension, shock.

Three distinct ribonucleoproteins from tobacco chloroplasts: each contains a unique amino terminal acidic domain and two ribonucleoprotein consensus motifs

Chloroplasts contain their own genetic system. Eighteen different split genes have been found among approximately 130 chloroplast genes from higher plants. However, little is known about the chloroplast splicing system. Mammalian heterogeneous nuclear ribonucleoproteins (hnRNP proteins) have been shown to be involved in splicing. We applied a purification procedure developed for HeLa cell hnRNP proteins, which uses a single-stranded DNA (ssDNA) affinity column, directly to the tobacco chloroplast lysate to isolate their chloroplast counterparts. Four proteins (mol. wt approximately 30 kd) bound strongly to the column. The amino-terminal sequences of three of them were determined and their cDNA clones were isolated from a tobacco leaf cDNA library. Sequence analysis of these clones revealed that all three proteins contain two ribonucleoprotein consensus sequences (RNP-CS), confirming their ribonucleoprotein (RNP) nature. The presence of putative transit peptides in their predicted protein sequences, and an in vitro import experiment confirmed they are located in the chloroplast. This is the first report of organellar proteins containing RNP-CS. In addition, these three chloroplast proteins have a very acidic amino-terminal domain, a novel feature among RNP proteins identified so far. They are expressed both in leaves and roots; their mRNA levels showed different light modulation in mature leaves. The three proteins might be involved in splicing and/or processing of chloroplast RNAs.

Collateral projections from the midbrain periaqueductal gray to the nucleus raphe magnus and nucleus accumbens in the rat. A fluorescent retrograde double-labelling study

Collateral projections of single neurons in the midbrain periaqueductal gray (PAG) to the nucleus accumbens (ACB) and nucleus raphe magnus (NRM) were observed in the rat by a fluorescent retrograde double-labelling technique. After injecting propidium iodide into the ACB and bisbenzimide into the NRM, doubly labelled PAG neurons were most frequently seen in the ventrolateral subnucleus and ventral part of the medial subnucleus at the middle and caudal levels of the PAG.

[Study on carcinogenic activity of several nickel compounds in mice]

This paper reports the result of the tumor in site induced by several nickel compounds in mice. Three nickel compounds (Ni3S2, NiCl, pure nickel powder) were injected separately to the right arm pit subcutaneously (5 mg/mouse). At the end of the 62nd week, the tested mice were sacrificed. Only nickel sulfide induced tumors in the site of injection, the incidence of tumor was 36%. The majority of the tumors were fibrosarcomas, only 2 rhabdomyosarcomas. The tumors might infiltrate into the surrounding tissues, a few metastasized to the liver and/or the lungs.

[Influence of zinc deprivation on thymus, spleen development and adenosine deaminase activity in young rats]

This study on the thymus and spleen development and ADA activity was done in young rats with zinc deprivation and supplementation. The serum zinc level, body weight, absolute and relative weight, and ADA activity of the thymus and spleen were compared between the experimental rats and the control group. Above indications were all decreased; especially both the thymus weight and the thymus ADA activity were markedly decreased in the zinc deficient group. The averages of thymic absolute weight, relative weight and ADA activity were dropped by 61.32%, 54.54% and 47.59%, respectively. After zinc supplementation for one month, all the body weight, weight of the thymus and spleen, and ADA activity of the spleen were recovered to the control group's level, while ADA activity of the thymus was 33.03% higher than that of the control group. Our data suggested that zinc was not only an important trace element in maintaining the growth of the body, the development of the thymus and spleen, but it may be an important agent to activate the ADA or to prompt synthesis of ADA.

Serotoninergic projections from the midbrain periaqueductal gray to the nucleus accumbens in the rat

A combined method of retrograde tracing of horseradish peroxidase (HRP) and serotonin (5-HT) immunocytochemistry indicated that some 5-HT-like immunoreactive neurons in the midbrain periaqueductal gray (PAG) of the rat send their axons to the nucleus accumbens. These PAG neurons are mainly located in the ventromedial and ventrolateral subdivisions at the middle and caudal levels of PAG.

[Comparative study of the ECG exercise test and ambulatory ECG monitoring after recovery from acute myocardial infarction]

Early ECG exercise tests (EET) and ambulatory ECG monitoring (AEM) were performed in 42 patients surviving AMI in order to determine the sensitivity of the two methods for detecting ST-segment deviation and arrhythmias. 23 patients had ST changes during EET and AEM. Of them, 21 patients had ST changes induced by EET and 10 were recorded by AEM. The more the ECG leads used for monitoring during and after EET, the higher the percentage of patients with ST changes will be. There were 2 cases with ST changes found in AEM only. All the 6 patients who had ST elevations during EET had an anterior infarction and echocardiograms did show that they had left ventricular aneurysms or abnormal ventricular wall movement. AEM recorded ventricular premature beats (VPBs) in 37 cases (88.0%), while EET induced VPBs in 8 patients. The 42 patients were followed up for an average time of 6 +/- 1.7 m. (3.4 to 9.3 m.) Cardiac death occurred in 2 cases. One of them had horizontal ST depression of 3 mm during EET, the other had a negative EET but multifocal VPBs during AEM. It is concluded that for detecting ST changes EET is more sensitive than AEM, while VPBs are more frequently found in AEM than in EET. The authors are of the opinion that for better, prediction of the prognosis of patients after AMI, it is preferable to have early EET in combination with AEM.

[Urine-Cr assay with diphenylcarbazide]

Systemic investigations of chromium determination in urine with diphenylcarbazide were carried out and suitable analytic conditions for the determination established. Urine samples were first digested with nitric acid-hydrogen peroxide and then the chromium in the sample was oxidized to the hexavalent state by permanganate in acidic medium. After the excess oxidizing reagent was destroyed with sodium nitrite, chromium (VI) combined with diphenylcarbazide, forming a stable red color. The average recovery was 101.1%, ranging from 82.0% to 115.8%. Coefficients of variation were in the range from 2.0% to 8.4%. The method can be conveniently applied to the analysis of trace chromium in urine samples with satisfactory sensitivity and recovery. The method was applied to the measurement of 180 normal and 124 CHD (coronary heart disease) urine samples from Chengdu city. The mean of chromium level in normal urine was 6.1 micrograms/L and the range with 95% confidence of urine chromium was determined as 1.7-11 micrograms/L. The mean of chromium level in CHD urine samples was 4.2 micrograms/L. By statistical analysis, there was a significant difference between the means of the two groups (t' = 6.9, P less than 0.05).

Mode-medium instability in an unstable resonator

The mode-medium instability of an active medium in an unstable resonator is investigated. The asymptotic solution due to Horwitz, valid for large Fresnel numbers in an empty cavity, is modified by introducing gain/ phase sheets in front of the resonator mirrors. The effect of medium coupling to the mode in the cavity is obtained by introducing a general time-independent Green's function in the Fox-Li formulation. The time evolution is then obtained by repeated integration of the beam propagation in the cavity. The diffractive terms are shown to grow rapidly at the expense of the geometric term. This instability responsible for the deterioration of the beam quality is studied numerically for a CO(2) lasing system as an example.

Differing patterns of human protooncogene expression in peripheral blood and bone marrow acute leukemia cells

The levels of protooncogene RNA in matched bone marrow and peripheral blood cells obtained from patients with newly diagnosed acute myelogenous leukemia were compared. While the absolute amounts of c-myc RNA in the matched specimens are similar, the levels are not correlated. In contrast, while the levels of c-fos RNA in the matched bone marrow and peripheral blood cells are correlated, the absolute levels of c-fos RNA differ substantially. The level of histone H3 RNA is higher in bone marrow cells than in peripheral blood cells. These substantial differences in protooncogene RNA levels between leukemic cells found in the bone marrow and in the peripheral blood make it impossible to accurately "characterize" gene expression in leukemic cells if studies are restricted to the cells in either compartment. Additionally, there appears to be a significant relationship between the levels of c-fos RNA and triose phosphate isomerase RNA and the height of the white blood cell count and between the level of c-fos RNA in marrow cells and the proportion of monocytic cells present.

Analysis of mutagenic nitroarenes in carbon black by high-performance liquid chromatography

A method was developed for the analysis of mutagenic nitroarenes in carbon black. The procedure included extraction, pre-separation column chromatography on silica gel, and determination by high-performance liquid chromatography (HPLC) using a diode-array detector. Different solvents, such as dichloromethane, benzene, toluene, and chlorobenzene were used for the extraction of carbon black. It was found that chlorobenzene yielded the highest amount of extracted material. The pre-separation, the optimization of the HPLC separation, the selection of detection wavelengths, and the calibration curve are discussed. 3-Nitro-9-fluorenone was detected in a treated carbon black, which is used for making carbon ink. The identification of peaks in the sample chromatograms was confirmed by comparing the retention time and the UV spectra with those of standards.

Wall-bound proteins of pollen tubes after self- and cross-pollination in Lilium longiflorum

Wall-bound proteins of Lilium longiflorum pollen tubes grown in vivo constitute 20-27% of the dry matter. Twenty-two-twenty-six percent of these proteins are NaCl soluble. Wall-bound proteins of in vivo pollen tubes are present in amounts 5-7 times that found in tubes grown in vitro. The protein pattern of wall-bound proteins is different between in vitro and in vivo grown pollen tubes. There are two kinds of pollen tube wall proteins: loosely bound and tightly bound. The latter are NaCl insoluble, contain hydroxyproline and are assumed to be covalently bound. No significant differences have been found in the amount of wall-bound proteins present between pollen tubes resulting after self-pollination and those resulting from cross-pollination. However, some band differences between self- and cross pollen tubes have been observed after gel electrophoresis. It can be supposed that some wall-bound proteins of pollen tubes are associated with the incompatibility reaction.

Induction of gastric adenocarcinoma in rats by N-methyl-N-nitro-N-nitroso-guanidine and ultrastructural changes of epithelial cells of the pyloric gland region

Rats of non-pure strain were allowed to drink N-Methyl-N-Nitro-N-Nitroso-guanidine (MNNG) solution (200-250 micrograms per milliliter) ad libitum. After 14 months, in addition to MNNG, each of them was fed with 1 ml of saturated NaCl solution once a week. During a period of 18 months, there were 5 cases of gastric adenocarcinoma and 2 cases of adenocarcinoma of the duodenum among 18 experimental rats. Besides, there were a few cases of papilloma of the fore-stomach and carcinoma of the lung. In 17 control rats, no tumors of the gastro-intestinal tract were seen. Microscopic examination of the mucosa of the pyloric gland region of the stomach in the experimental rats showed that the deep epithelial cells of the gastric pit exhibited a marked degree of proliferation and a malignant change had started in these cells. Electron microscopic observation of these epithelial cells revealed that the the proliferating cells showed only increased nucleocytoplasmic ratio, while those with atypical hyperplasia showed that the form of the nucleus and the changes in the basement membrane and intercellular junctions were somewhat similar to those of malignant cells. It is believed that increase in concentration of the carcinogens and prolongation of the time of contact with them may induce malignant tumors in the insensitive animal.