Pheromone, juvenile hormone, and social status in the male lobster cockroach Nauphoeta cinerea

In this study, the major pheromone component, 3‐hydroxy‐2‐butanone (3H‐2B), released by dominants was measured during early scotophase. Both the JH III titer in the hemolymph and the 3H‐2B content of the sternal glands of the dominants and subordinates were then measured during late scotophase and late photophase. These investigations were performed on encounter days 1, 2, 3, 5, 7, 9, 12, and 20. The results showed that, for non‐aggressive posture (AP)‐adopting socially naïve males (SNMs), both the 3H‐2B release and the hemolymph JH III titer were maintained at a low level. Once a fight occurred, 3H‐2B release was raised significantly in the AP‐adopting dominants, but not in non‐AP‐adopting subordinates, and remained raised throughout the entire experimental period. At 30 min after the first encounter, the hemolymph JH III titer was significantly increased in dominants, but not in subordinates. A significantly higher hemolymph JH III titer was observed in dominants during late scotophase on days 3, 5, 12, and 20 and during late photophase on days 3, 5, and 20. After fighting, the sternal gland 3H‐2B content of the dominants or subordinates was significantly lower than in SNMs. In dominants, the sternal gland 3H‐2B content during late scotophase was significantly lower than that during late photophase in the first 9 domination days, while, in the subordinates, the 3H‐2B content during late scotophase was either similar to, or significantly higher than, that in late photophase. In the dominants, 3H‐2B release and JH III titer were positively correlated. In rank switchers, the switched social status was positively correlated with both 3H‐2B release and JH III titer. Comparison of 3H‐2B release and JH III titer in 1‐time, 3‐time, or 5‐time dominants showed that, although winning significantly increased both 3H‐2B release and JH III titer, there is no significant difference in 3H‐2B release between 3‐ and 5‐time winners, while the JH III titer was most significantly increased in the 3‐time winners. The possible relationship between pheromone release, JH III titer, and social status is discussed. Arch. Insect Biochem. Physiol. 2008. © 2008 Wiley‐Liss, Inc.     

抗—HBs国际单位RIA一点法定量测定与计算方法的探讨

在Radio-immuno Assay(RIA)试验测抗－HBs国际单位的简易定量与计算中,采用RIA一点法测定,以分析表达式mIU/ml＝SC（mIU/ml)[exp(0.69315S-NC/SC-NC-1]进行结果计算。此式可以常用对数式表示为mIU/ml=SC(mIU/ml)[lg^-1(0.30103S-NC/SC-NC-1],当（S－NC）在0．3－1．1界线内时,其计算结果的相对误差小于6％,是目前误差最小的简易计算方法。同时还推算求出Holliger公式的阳性对照的最适含量为124．26mIU／ml,Richardson公式的阳性对照为125mIU/ml,中国药品生物制品检定所公式的阳性对照为92．5mIU/ml。     

Alteration of opioid peptide concentrations in the rat pituitary following survivable closed head injury

Concentration changes of methionine enkephalin-like immjnoreactivity (ME-li) and -endorphin-like immunoreactivity (BE-li) in the rat pituitary following diffuse brain injury were studied. Closed head injury was induced by a weight-drop trauma device (450 g×2 m). The level of closed head injury used in this study altered the pituitary opioid peptide concentrations. The level of ME-li did not change in the experimental groups 3 hours, 10 hours, 24 hours, and 3 days after the trauma, but significantly increased by 34% 10 days after the trauma. BE-li remained constant 3 hours and 10 hours following the injury, increased by 48% at 24 hours, and remained at this level for 10 days after the trauma (44% at 3 days, and 40% at 10 days). The levels of ME-li and BE-li in the control sham-operated rats did not change during these times. The present measurements of BE-li and ME-li in the pituitary indicate that the opioid peptides that derive from two different neuropeptidergic systems, proopiomelanocortin (POMC) and preproenkephalin A, respectively, may participate in the pathophysiology of a closed head injury.     

Response of monkeys to porcine zona pellucida as detected by a solid-phase radioimmunoassay

The immunological response of cynomolgus monkeys (Macaca fascicularis) to immunization was evaluated utilizing collagenase-isolated pig zona pellucida. Six weeks after initial immunization a high serum titer of antibody was exhibited. Serum antibody titers demonstrated a noticeable decline 5 months after booster injections were discontinued. The assay method used is rapid and is capable of detecting antibody in serum dilutions of 1:78,000, as compared to 1:125,000 with the indirect fluorescence assay.     

Existence of Met-enkephalin-Arg6-Gly7-Leu8 with Met-enkephalin,Leu-enkephalin and Met-enkephalin-Arg6-Phe7 in the brain of guinea pig,rat and golden hamster

High performance liquid chromatography (HPLC) coupled with specific radioimmunoassays for methionine-enkephalin-Arg⁶-Gly⁷-Leu⁸ (Met-E-Arg⁶-Gly⁷-Leu⁸), methionine-enkephalin (Met-E), leucine-enkephalin (Leu-E) and methionine-enkephalin-Arg⁶-Phe⁷ (Met-E-Arg⁶-Phe⁷) has demonstrated that Met-E-Arg⁶-Gly⁷-Leu⁸ exists together with Met-E, Leu-E and Met-E-Arg⁶-Phe⁷ in the brain of guinea pig, rat and golden hamster. The content of Met-E-Arg⁶-Gly⁷-Leu⁸ was comparable to those of Leu-E and Met-E-Arg⁶-Phe⁷, whereas that of Met-E was the highest among the four opioid peptides. These results are compatible with the recent studies on the nucleotide sequence of cloned cDNA for preproenkephalin from bovine adrenal medulla, which reveal that this precursor molecule contains four copies of Met-E and one copy each of Leu-E, Met-E-Arg⁶-Phe⁷ and Met-E-Arg⁶-Gly⁷-Leu⁸. The co-existence of Met-E-Arg⁶-Gly⁷-Leu⁸ with Met-E, Leu-E and Met-E-Arg⁶-Phe⁷ suggests that their biosynthetic pathway in the brain is similar to that in the adrenal medulla.     

Reduction of N-acetyl methionine sulfoxide: A simple assay for peptide methionine sulfoxide reductase

A simple and rapid assay has been developed to measure the enzymatic activity of peptide methionine sulfoxide reductase. The assay is based on the reduction of labeled N-acetylmethionine sulfoxide to N-acetylmethionine. The N-acetylmethionine can be separated from the substrate by extraction into ethyl acetate.     

Evidence that somatomedin is synthesized by multiple tissues in the fetus

Production of somatomedin-C, a growth hormone-dependent peptide believed to mediate the growth-promoting actions of growth hormone, has been assessed using explants of fetal mouse tissues. Quantitation of this peptide in media of explants cultured for 3 days has been accomplished with a membrane receptor assay for somatomedin and a specific radioimmunoassay for somatomedin-C. Somatomedin-C is produced by the 11-day-gestation fetal mouse liver, increases exponentially in parallel with liver growth until the 16th day of gestation, and falls postnatally. Media somatomedin is believed to be derived by de novo synthesis since saline extracts of liver and most other fetal tissues contain only a small fraction of the activity in culture media. The immunoreactive material secreted into media appears to be closely related to human somatomedin-C since it produces dilution curves which are parallel to those of pure hormone, migrates on Sephacryl 200 at a size similar to that of one of the components of human serum somatomedin-C, dissociates into small molecular weight material with acid treatment, and isofocuses in a range comparable with that of somatomedin-C purified from human serum. Eleven-day limb bud mesenchymal micromass cultures and 17-day-gestation intestine, heart, brain, kidney, and lung also synthesize immunoreactive somatomedin-C in serum-free medium. For these tissues, the media activity was far in excess of the tissue extractable activity. Somatomedin activity in excess of the tissue extractable activity, however, was not found in media from 17-day-gestation placenta. The finding that multiple tissues synthesize somatomedin-C raises the possibility that the primary biological actions of this hormone are exerted locally at its sites of origin. Although a function of this type by a peptide has not been widely suspected, it seems plausible that the cells of fetal tissues are capable of producing local mitogens in much the same manner as the postulated inducers of tissue differentiation.     

Suppression of narcotic withdrawals and plasma ACTH by auricular electroacupunture.

Auricular electroacupuncture (AES) has been found to be successful in the suppression of withdrawal symptoms of morphine-addicted mice. In abrupt withdrawals precipited by naloxone, the plasma adrenocorticotropin (ACTH) rises to a high level which can also be effectively suppressed by AES. This elevation of plasma ACTH is not due to naloxone, as naloxone has no effect on the ACTH level in non-addicted mice. The possible physiological effect produced by AES is discussed.