Chronic treatment of female rhesus monkeys with low doses of the antiprogestin ZK 137 316: establishment of a regimen that permits normal menstrual cyclicity

Large doses of antiprogestin typically disrupt menstrual cyclicity. A chronic low-dose regimen of the potent new antiprogestin ZK 137 316, which permits continued menstrual cyclicity but alters gonadal- reproductive tract activity, was established. Rhesus monkeys received vehicle (n = 6) or 0.01 (n = 8), 0.03 (n = 8) or 0.1 (n = 5) mg ZK 137 316/kg body weight daily for five menstrual cycles (C-1 to C-5). Oestradiol, progesterone and gonadotrophin profiles were normal during cycles involving vehicle and 0.01 and 0.03 mg ZK 137 316/kg body weight. In the 0.1 mg/kg group, mid-cycle oestradiol and gonadotrophin surges, and subsequent progesterone production, were absent in C-3 and C-5. Ovarian cyclicity was accompanied by timely menstruation in the vehicle and 0.01 mg/kg groups. By C-3, half the animals in the 0.03 mg/kg group and all animals in the 0.1 mg/kg group were amenorrhoeic. A corpus luteum was noted during the mid-luteal phase of C-5 in the vehicle, 0.01 mg/kg and 0.03 mg/kg groups. Large antral and cystic follicles were evident in the 0.1 mg/kg group. Thus, a daily treatment with 0.01 mg/kg ZK 136317 permitted normal menstrual cyclicity in macaques. While the daily administration of 0.03 mg/kg ZK 136 317 allowed ovarian cyclicity, menstruation was disrupted in some animals. Increasing the dose to 0.1 mg/kg antagonized pituitary function and resulted in anovulation and amenorrhoea. A chronic low-dose regimen of the antiprogestin ZK 137 316, which permits normal ovarian/menstrual cyclicity, has potential as a contraceptive in women.      

Postnatal development of GABA-mediated synaptic inhibition in rat hippocampus

Developmental alterations in GABAergic synaptic transmission were examined physiologically and biochemically in hippocampus of rats from 3 days of age to adulthood. Neither antidromic nor orthodromic stimulation could elicit identifiable inhibitory postsynaptic potentials in CA1 neurons in slices from rats 5 or 6 days of age. In contrast, at this age these stimuli result in large inhibitory postsynaptic potentials in CA3 pyramidal cells. In the latter cells orthodromic stimulation produced a brief monosynaptic excitatory postsynaptic potential which was followed by a large prolonged biphasic hyperpolarization. These signals were strikingly similar to those recorded in 1-month-old rats. In addition, large recurrent inhibitory postsynaptic potentials were produced by antidromic stimulation. By postnatal day 9 similar inhibitory postsynaptic potentials could be elicited in a majority of neurons of the CA1 subfield. As in mature pyramidal cells, application of GABA antagonists, such as bicuculline, selectively eliminated the antidromic inhibitory postsynaptic potential and the first component of the biphasic inhibitory postsynaptic potential generated by stimulation of stratum radiatum. In the CA3 subfield, this blockade of GABA receptors resulted in prolonged afterdischarges in slices from immature but not month-old rats. Measurements of the equilibrium potential and the conductance of antidromic inhibitory postsynaptic potentials in CA3 neurons were very similar when made during the first postnatal week and at 1 month of age. While on days 10-11 the equilibrium potential was very similar to measurements made at these other ages, the conductance was 3-4 times greater. The activity of glutamate decarboxylase, the synthetic enzyme for GABA, was very low at 3 days in hippocampus, and increased until 30 days of age at which time adult values were obtained. By comparison, hippocampal GABA levels were high early in postnatal life. Glutamate decarboxylase activities in microdissected CA3 and CA1 subfields were similar in immature hippocampus. These results demonstrate dramatic differences in the ontogenesis of functional GABAergic inhibitory synaptic transmission in the CA1 and CA3 subfields of rat hippocampus. The late development of GABA-mediated synaptic inhibition in the CA1 subfield could play a role in the susceptibility of immature hippocampus to seizures. However, the large GABA-mediated inhibitory postsynaptic potentials present in the CA3 subfield at the same age have a critical role in dampening neuronal excitability.(ABSTRACT TRUNCATED AT 400 WORDS)     

The use of additive and subtractive approaches to examine the nuclear localization sequence of the polyomavirus major capsid protein VP1.

A nuclear localization signal (NLS) has been identified in the N-terminal (Ala1-Pro-Lys-Arg-Lys-Ser-Gly-Val-Ser-Lys-Cys11) amino acid sequence of the polyomavirus major capsid protein VP1. The importance of this amino acid sequence for nuclear transport of VP1 protein was demonstrated by a genetic "subtractive" study using the constructs pSG5VP1 (full-length VP1) and pSG5 delta 5'VP1 (truncated VP1, lacking amino acids Ala1-Cys11). These constructs were used to transfect COS-7 cells, and expression and intracellular localization of the VP1 protein was visualized by indirect immunofluorescence. These studies revealed that the full-length VP1 was expressed and localized in the nucleus, while the truncated VP1 protein was localized in the cytoplasm and not transported to the nucleus. These findings were substantiated by an "additive" approach using FITC-labeled conjugates of synthetic peptides homologous to the NLS of VP1 cross-linked to bovine serum albumin or immunoglobulin G. Both conjugates localized in the nucleus after microinjection into the cytoplasm of 3T6 cells. The importance of individual amino acids found in the basic sequence (Lys3-Arg-Lys5) of the NLS was also investigated. This was accomplished by synthesizing three additional peptides in which lysine-3 was substituted with threonine, arginine-4 was substituted with threonine, or lysine-5 was substituted with threonine. It was found that lysine-3 was crucial for nuclear transport, since substitution of this amino acid with threonine prevented nuclear localization of the microinjected, FITC-labeled conjugate.     

Tourniquet inflation after intra-articular morphine and bupivacaine administration following knee arthroscopy

We performed a randomized doubled-blind study to evaluate whether there was a benefit in delay in tourniquet deflation with intra-articular administration of morphine and bupivacaine following operative arthroscopic surgery. In 34 patients the tourniquet was deflated immediately and in 38 patients the tourniquet remained inflated for 10 min following injection. The analgesic efficacy was assessed using pain scores and the amount of supplementary analgesia required. The results demonstrate no benefit in delay in tourniquet deflation.     

Preprocessor Adapts Cardiovascular Signals to a Minicomputer

A laboratory-developed analog signal processor, driven by a conventional polygraph recorder and associated signal conditioning devices, provides automatic heart beat-by-heart beat preprocessing of various cardiovascular functions for input to a laboratory-type minicomputer. The technique of preprocessing individual functions, integrated with the minicomputer system which includes an A/D converter and teletype as input-output peripherals, provides a low-cost data acquisition and reduction system for the on-line computation and analysis of cardiovascular functions in experimental research applications. Such preprocessing more efficiently uses the minicomputer's memory to handle large amounts of information since the digitized data is in the form of one data sample, per function, per heart beat. Preprocessing analog data provides a low density data format and simplified software programs that are ideally suited for the utilization of a minicomputer in this on-line application.     

Nucleic acid vaccines

There are no adequate vaccines against some of the new or reemerged infectious scourges such as HIV and TB. They may require strong and enduring cell-mediated immunity to be elicited. This is quite a task, as the only known basis of protection by current commercial vaccines is antibody. As DNA or RNA vaccines may induce both cell-mediated and humoral immunity, great interest has been shown in them. However, doubt remains whether their efficacy will suffice for their clinical realization. We look at the various tactics to increase the potency of nucleic acid vaccines and divided them broadly under those affecting delivery and those affecting immune induction. For delivery, we have considered ways of improving uptake and the use of bacterial, replicon or viral vectors. For immune induction, we considered aspects of immunostimulatory CpG motifs, coinjection of cytokines or costimulators and alterations of the antigen, its cellular localization and its anatomical localization including the use of ligand-targeting to lymphoid tissue. We also thought that mucosal application of DNA deserved a separate section. In this review, we have taken the liberty to discuss these enhancement methods, whenever possible, in the context of the underlying mechanisms that might argue for or against these strategies.