Possible effect of bromocriptine on the insulin receptor

The administration of 0.00011 mg/g weight/day of bromocriptine (CB154) for 7 days to Wistar rats, improved the peripheral glucose uptake without significant changes in plasma insulin level, during the intravenous glucose tolerance test (0.33 g/kg). The mode of the bromocriptine action on binding of 125I insulin to erythrocyte insulin receptors has been evaluated. The total number of sites was greater with bromocriptine (513.1 +/- 124.1 pM/1,CB154 815.6 +/- 107.9 pM/l) (p less than 0.01). The high affinity/low capacity compound of insulin receptor, in CB154 rats (51.8 +/- 16.8 pM/l) was higher than in normal rats (18.3 +/- 8.9 pM/l) (p less than 0.005). Additional studies indicated that CB154 had no effect on the rate of association and dissociation of 125I insulin from rats erythrocyte insulin receptors. The degradation of insulin or the erythrocyte receptor sites do not change, after the treatment with CB154.     

Female transfer in primates

Intergroup transfer by males is nearly universal among social primates. Furthermore, among the most frequently studied monkeys-savanna baboons and Japanese and rhesus macaques—females typically remain in their natal groups, so troops are composed of related matrilines. These facts strongly support two major theories: (l) that kin selection is a powerful force in patterning sociality (if one is to live in a group, one should prefer a group of one’s relatives); and (2) that the ultimate explanation for intergroup transfer is the avoidance of inbreeding depression (though both sexes would prefer to live with kin, one sex has to disperse to avoid inbreeding and for a variety of reasons the losing sex is generally male). Substantial rates of transfer by females in social species with routine male transfer would cast doubt on both ideas. In fact, evidence reviewed here indicates that female transfer is not unusual and among folivorous primates (e.g., Alouatta,the Colobinae) it seems to be routine. In addition to casting doubt on the demographic significance of inbreeding avoidance and favoring mutualistic and/or game theory interpretations of behavior over nepotistic ones, this finding supports the hypothesis that predator detection is the primary selective pressure favoring sociality for many primates. Finally, while female bonding [sensuWrangham, R. W. (1980), Behaviour75:262–299] among primates appears to be less common than generally believed, the observed correlation between female transfer and morphological adaptations to folivory provides empirical support for Wrangham’s model for the evolution of female-bonded groups.     

Proteinase inhibitors of bovine nasal cartilage.

Extracts from bovine nasal cartilage with 1 M-guanidinium chloride were fractionated by ultrafiltration. Gel chromatography of the low-molecular-weight material resolved three distinct fractions with inhibitory activity against (a) collagenases (22000 mol.wt.), (b) thiol proteinases cathepsin B and papain (13000 mol.wt.), and (c) trypsin and other serine proteinases (7000 mol.wt.).     

Assembly of Bacillus subtilis phage phi29. 1. Mutants in the cistrons coding for the structural proteins.

The effect of mutations in the cistrons coding for the phage structural proteins has been studied by analyzing the phage-related structures accumulated after restrictive infection. Infection with susmutants in cistron 8, lacking both the major head and the fiber protein, does not produce any phage-related structure, suggesting a single route for the assembly of phage phi29; infection with ts mutants in this cistron produces isometric particles. Mutants is cistron 9, coding for the tail protein, TP1, produce DNA-free prolate heads with an internal core; these particles are abortive and contain the head proteins HPO, HP1 and HP3, the upper collar protein NP2 and the nonstructural proteins p7, p15 and p16. Mutants in cistron 10, coding for the upper collar protein, NP2, produce DNA-free isometric heads also with an internal core; they contain the head proteins and the nonstructural protein p7, suggesting that this protein forms the internal core. Mutants in cistrons 11 and 12, coding for the lower collar protein, NP3, and the neck appendages, NP1, respectively, give rise to the formation of DNA-containing normal capsids and DNA-free prolate particles, more rounded at the corners than the normal capsids and with an internal core; the DNA-containing 11-particles are formed by the head proteins and the upper collar protein; the DNA-free 11-particles contain, besides these proteins, the nonstructural protein p7 and a small amount of proteins p15 and 16. The DNA-containing 12-particles have all the normal phage structural proteins except the neck appendages, formed by protein NP1; the DNA-free particles are similar to the DNA-free 11-particles. After restricitive infection mutant sus14(1241) has a delayed lysis phenotype and produces a phage burst higher than normal, after artificial lysis. It produces DNA-containing particles, identical to wild-type phage, which have all the normal phage structural proteins, and DNA-free prolate particles, more rounded at the corners than the final phage particles and with an internal core; the last particles contain the same proteins as the DNA-free 11 or 12-particles. These particles could represent a prohead state, ready for DNA encapsulation. None of the DNA-containing particles have the nonstructural proteins p7, p15 or p16, suggesting that these proteins are released from the proheads upon DNA encapsulation.     

Low velocity gradient flow birefringence and viscosity changes in hyaluronate solutions as a function of pH.

The flow birefringence and extinction angle over a velocity gradient range of approximately 5–100 sec^?1, and the zero shear-viscosity have been obtained from human umbilical cord hyaluronic acid at concentrations of 0.25, 0.125 and 0.0625%, and pHs 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5 and constant ionic strength 0.1. The data indicate a large change in optical anisotropy as a function of pH, with most of the transition in the pH range 7.0–7.5, i.e., across the physiological range. The sign of the anisotropy changes between pH 8.0 and 8.5. These results, together with changes in the extinction angle and intrinsic viscosity as a function of pH, suggest a pH-dependent structural change in the system. Due to the abruptness of the transition, as evidenced by the intrinsic viscosity and flow birefringence, it is probable that the structural transition is cooperative. If the data are interpreted in terms of the Rouse-Zimm Gaussian subchain theory, a modification of the model in terms of the Haller-Cerf concept of internal viscosity is required. Thus, the demonstrated properties of hyaluronate solutions indicate a system with memory of stress. Due to the presence of large concentration effects discernible in the extinction angle measurements, hyaluronic acid probably exists as a network in solution. The results are discussed with respect to the mechanoelectrical transducing properties of hyaluronates and stress-dependent changes in ORD already reported.     

The electrolytic preparation of bioactive radioiodinated parathyroid hormone of high specific activity.

A technique for the preparation of microgram quantities of bovine parathyroid hormone (bPTH) labeled with carrier-free ¹²⁵I to a specific activity of 1300 Ci/mmol is described. A restructured and simplified apparatus was used for electrolytic iodination, making it feasible to use reaction volumes of 100 to 200 ml. The miniaturized setup requires only a small platinum crucible connected via an agar-KCl salt bridge to a saturated KCl solution, a battery to drive the reaction, and a voltmeter to monitor the potential difference between the reference-saturated KCl solution (via a calomel electrode) and the platinum crucible. The [¹²⁵I]-labeled bPTH elutes as a single species when chromatographed on a Biogel P-10 column equilibrated in 3 m guanidine HCl-2.3 m formic acid, and it retains full biologic activity when bioassayed in vivo. It is evident that bPTH labeled to a high specific activity with ¹²⁵I does not suffer in regard to its biological potency.     

Platelet aggregation and sphingomyelinase D activity of a purified toxin from the venom of loxosceles reclusa

A facile and quantitative assay for measuring the activity of sphingomyelinase D in recluse spider venom has been developed using L-α-[palmitoyl-1-¹⁴C]lysophosphatidylcholine as substrate. This assay avoids the problem of substrate insolubility that occurs when sphingomyelin and other lipids are used as subtrates. This assay has been employed in gel filtration and isoelectric focusing isolation techniques to purify sphingomyelinase D from spider venom. The purified sphingomyelinase exhibits four active enzyme forms in isoelectric focusing with pI values of 8.7, 8.4., 8.2, and 7.8. Each active form when examined in SDS-polyacrylamide gel electrophoresis gave an estimated molecular weight of 32 000. The four active enzyme forms were immunologically cross-reactive with each other as demonstrated with radioimmune assays using an antiserum developed to one of the active forms. Each active form hydrolysed sphingomyelin to release choline and produce N-acylsphingosine phosphate. One of the active enzyme forms was characterized further in dermonecrosis and platelet aggregation measurements. This purified sphingomyelinase D was identified as a poisonous toxin that can develop the typical dermonecrotic spider lesion when injected into experimental animals at levels expected to be delivered in a normal bite. Furthermore, the purified toxin acts to aggregate human blood platelets. The toxin-induced platelet aggregation has been related to serotonin release as aggregation occurs, and it has been shown to be inhibited by EDTA over the range of 0.6 to 3.0 mM EDTA. It is suggested that spider-induced dermonecrosis could result in part from platelet aggregation at and near the site of envenomation.     

Fetal cells in the maternal blood

Summary In an attempt to stimulate fetal cells in the maternal blood to mitotic division, peripheral blood lymphocytes were cultured from ten primiparous women and six multiparous women. In the case of the ten primiparous women, PWM was used to stimulate lymphocytes in 3- and 7-day cultures made at the 16th, 20th, 24th, and 28th week of gestation. Altogether, 10565 mitoses were analyzed after quinacrine staining of cells from five mothers who each subsequently gave birth to a male infant, and not a single XY mitosis was found.In the case of the multiparous women, lymphocyte cultures, with PHA or LPS as mitogen and MLC, were initiated between the 13th and 20th week of pregnancy. Four of the mothers were pregnant with a male child, and two with a female child. From cultures of each of the four mothers expecting a boy, a total of 9721 mitoses were analyzed after quinacrine staining, and not a single XY mitosis was found. However, one XY cell was found in the culture from one of the two women who delivered a girl. The XY mitosis probably originated from a pregnancy 8 months earlier which terminated in a male infant.In an attempt to culture and obtain good chromosome preparations from small numbers of cells, it was shown that a good mitotic response and good chromosome preparations could be obtained from as few as 6000 lymphocytes.