Assessment of bioequivalence after subcutaneous and intramuscular administration of urinary gonadotrophins

The objective was to demonstrate bioequivalence between s.c. and i.m. administration of Humegon (FSH/LH ratio 1:1) and Normegon (FSH/LH ratio 3:1). In two randomized, single-centre, cross-over studies, 18 healthy volunteers on each formulation were assigned to one of the two administration sequences. Subjects were given single doses of one of the above gonadotrophins after endogenous gonadotrophin production had first been suppressed using high-dose oral contraceptive. Subsequently, rate (Cmax, tmax) and extent (AUC) of absorption of follicle stimulating hormone (FSH) and luteinizing hormone (LH) were determined for 14 days. For Cmax and AUC, analysis of variance (ANOVA) was performed on log-transformed data and for tmax ANOVA was performed on ranks. Intramuscular and s.c. injections of Humegon were bioequivalent with respect to the main pharmacokinetic parameters, being AUC and Cmax of FSH absorption. Intramuscular and s.c. injections of Normegon were bioequivalent with respect to the AUC of FSH and not bioequivalent with respect to the Cmax of FSH. For tmax of FSH as well as for most LH variables of both preparations, bioequivalence could not be proven due to the high intra- and interindividual variability and/or concentrations being close to the detection limit. Thus, the main pharmacokinetic FSH variables after i.m. and s.c. administration of Humegon and Normegon were bioequivalent.      

The partition of sodium fluxes in isolated toad oocytes

1. The rate constant for Na efflux from the oocyte calculated from (d/dt) (ln [Na^*]_i]) is only approximately 52% of that calculated from (d/dt)[(ln(d[Na^*]_i)dt)]. The difference may be interpreted by supposing that 48% of the internal Na of the oocyte is either bound to proteins or sequestered in cell organelles.2. The mean rate constant for Na efflux was 6·4 × 10^-3 min^-1 corresponding to an apparent Na efflux rate of 13·3 p-mole/cm².sec. When this is corrected for the increase in surface area produced by microvilli the true efflux rate is 1·1-1·3 p-mole/cm².sec.3. The action of ouabain (1-5 μM) appears to involve two different effects: (a) there is 48-65% inhibition of the membrane Na pump, and (b) there is a release of some of the sequestered Na in the cell.4. Removal of external K causes a 40% reduction in Na efflux although this value may be an underestimation owing to the presence of K which has leaked from the cell and may be retained near the cell surface.5. Raising the external K concentration to 15 mM reduces the inhibitory effect of ouabain by approximately a half.6. It was concluded that the Na pump in the toad oocyte may have a slightly lower level of activity than that in frog muscle, but that its general properties are similar to those in frog muscle and some other animal cells.     

Apparent replication of suggestive linkage on chromosome 16 in the NIMH genetics initiative bipolar pedigrees

Analyses of a replication sample of families collected as part of the National Institute of Mental Health (NIMH) Genetics Initiative for bipolar disorder provide further evidence for linkage to a region of chromosome 16. Families who had a bipolar I (BPI) proband and at least one BPI or schizoaffective, bipolar type (SABP) first-degree relative were ascertained for the purpose of identifying genes involved in bipolar affective disorder. A series of hierarchical models of affected status was used in linkage analyses. Initial genetic analyses of chromosomes 3, 5, 15, 16, 17, and 22, completed at Indiana University in 540 subjects from 97 families, suggested evidence of linkage to chromosomes 5, 16, and 22 [Edenberg et al., 1997: Am J Med Genet 74:238-246]. Genotyping was subsequently performed on these chromosomes in a replication sample of 353 individuals from 56 families. Nonparametric linkage analyses were performed using both affected relative and sibling pair methods. Analyses in the new sample on chromosome 16, using the broadest model of affected status, corroborate previously reported suggestive linkage to the marker D16S2619. Combining the initial and replication samples further increased the evidence of linkage to this region, with a peak lod score of 2.8.     

The effects of cortisol infusion upon hormone secretion from the anterior pituitary and subjective mood in depressive illness and in controls.

The aims of this study were to determine whether the administration of cortisol has a significant effect on mood in patients with depression and whether the effects of cortisol on changes in plasma hormone concentrations are like those of synthetic corticosteroids. Twelve patients had major depression and one each had dysthymic disorder and a depressive adjustment disorder. Five were male and nine were female. All were in-patients. Eight normal subjects, two females and six males, were used as controls. Basal beta-endorphin concentrations were 2- to 3-fold higher in depressed patients than in control subjects, but there were no significant differences between the patient and control groups in the basal (pre-infusion) plasma concentrations of ACTH, cortisol, growth hormone or prolactin. Cortisol, but not saline infusion resulted in a significant improvement in self rated mood. Surprisingly, cortisol infusion at first increased plasma beta-endorphin concentrations. At later times after cortisol infusion, plasma beta-endorphin concentrations decreased as did the plasma concentrations of ACTH and growth hormone; prolactin levels were increased. These results show (i) that cortisol infusion raises mood significantly in major depression, (ii) that plasma beta-endorphin concentration is a potential marker of major depression (iii) that rather than blunting of corticosteroid effects, responses to cortisol may even be enhanced in depressive illness. The unexpected, initial increase in beta-endorphin stimulated by cortisol, suggests that the action of cortisol is not simply one of negative feedback inhibition, but may involve mineralocorticoid, as well as glucocorticoid receptors.     

Metabotropic glutamate receptors are associated with non-synaptic appendages of unipolar brush cells in rat cerebellar cortex and cochlear nuclear complex

Unipolar brush cells (UBCs) are a class of small neurons that are densely concentrated in the granular layers of the vestibulocerebellar cortex and dorsal cochlear nucleus. The UBCs form giant synapses with individual mossy fibre rosettes on the dendrioles which make up their brush formations and are provided with numerous, unusual non-synaptic appendages. In accord with the glutamatergic nature of mossy fibres, our previous post-embedding immunocytochemical studies indicated that various ionotropic glutamate receptor subunits are localized at the post-synaptic densities of the giant synapses, whereas the non-synaptic appendages are immunonegative. On the contrary, the metabotropic glutamate receptors mGluR1 and mGluR2/3 are situated at the non-synaptic appendages and are lacking at the post-synaptic densities. Other authors, however, have shown that antibodies to these metabotropic receptors stain both appendages and post-synaptic densities. In the present study, we have re-evaluated the distribution of metabotropic glutamate receptors in the UBCs of the cerebellum and the cochlear nuclear complex by light and electron microscopic pre-embedding immunocytochemistry with subtype-specific antibodies. We confirm that UBCs dendritic brushes are densely immunostained by antibody to mGluR1 particularly in the cerebellum and that antibody to mGluR2/3 labels at least a percentage of the UBC brushes in both the cerebellum and cochlear nuclei. At the ultrastructural level, it appears that mGluR1 and mGluR2/3 immunoreactivities are not associated with the post-synaptic densities of the giant mossy fibre–UBC synapses, but instead are concentrated on the non-synaptic appendages of the cerebellar UBCs. The non-synaptic appendages, therefore, may be an important avenue for regulating the excitability of UBCs and mediating glutamate effects on their still unknown intracellular signal transduction cascades. We also show that the pre-synaptic densities of UBC dendrodendritic junctions are mGluR2/3 positive. As previously demonstrated, antibodies to mGluR1 and mGluR2/3 label subsets of Golgi cells. Antibody to mGluR5 does not stain UBCs in the cerebellum and cochlear nucleus and reveals the somatodendritic compartment of Golgi cells situated in the core of the cerebellar granular layer, whilst cochlear nucleus Golgi cells are mGluR5 negative.     

IS1245 Restriction Fragment Length Polymorphism Typing of Mycobacterium avium Isolates: Proposal for Standardization

Mycobacterium avium has become a major human pathogen, primarily due to the emergence of the AIDS epidemic. Restriction fragment length polymorphism (RFLP) typing, using insertion sequence IS1245 as a probe, provides a powerful tool in the molecular epidemiology of M. avium-related infections and will facilitate well-founded studies into the sources of M. avium infections in animal and environmental reservoirs. The standardization of this technique allows computerization of IS1245 RFLP patterns for comparison on a local level and the establishment of M. avium DNA fingerprint databases for interlaboratory comparison. Moreover, by combining international DNA typing results of M. avium complex isolates from a broad spectrum of sources, long-lasting questions on the epidemiology of this major agent of mycobacterial infections will be answered.     

Axonal projections of single bulbospinal inspiratory neurons revealed by spike-triggered averaging and antidromic activation

Activity was recorded extracellularly from 26 inspiratory bulbospinal neurons in anesthetized, paralyzed, artificially ventilated cats. All but one were located in the ventral respiratory group. A neuron was classified as either I alpha or I beta by comparing its firing pattern during inspiratory cycles with lung inflation to its pattern when lung inflation was withheld during the central inspiratory phase (2, 14, 15). In this study, the projection and conduction velocity of these axons were determined using two methods: antidromic activation (AA) of the bulbospinal neurons and spike-triggered averaging (STA) of the extracellular field potentials. These methods have been compared directly because the same electrode was used both for stimulating the axon of the bulbospinal neuron and recording its axonal potential in the same location. Axonal projections from these neurons were mapped in the contralateral spinal cord with a mobile electrode by determining where the lowest stimulus threshold occurs for AA and greatest axonal potential can be recorded with STA. The locations of these axons were in the ventral and lateral funiculi. Each method determined a similar location for an axon. Positions of 10 axons were determined at both the third (C3) and fourth (C4) cervical segments. Single axons maintained their positions in either descending tract from rostral C3 to mid-C4. In five of six cases where two "neighboring" medullary units were characterized, the axons of each pair projected together within 350 micron of each other in the cervical spinal cord. Estimates of mean axonal conduction velocity (CV) from antidromic activation from a single stimulus site, "single-point AA," were as much as 42% less than corresponding estimates from STA extracellular field potentials at that point (P less than 0.001). Such single-point estimates were less than determinations that were calculated from the difference in conduction time and the difference in conduction distance from two points in the spinal cord. These two-point determinations averaged 55.4 +/- 13.1 m/s (using AA) and 53.3 +/- 13.1 (using STA) for 10 neurons. These values were not significantly (P greater than 0.2) different from each other and are greater than most earlier reports, which used the single-point AA method. Either method, AA or STA, can be used to determine axonal position and CV. The advantages and disadvantages of each method are discussed.(ABSTRACT TRUNCATED AT 400 WORDS)     

Biological resurfacing of the knee: a review of surgical management

Lesions of the articular surfaces of the knee have been managed by various techniques over the last 50 years. Surgical management has involved: excising the damaged area, refashioning the underlying bone to produce a fibrous response, and introducing allograft, autograft and synthetic materials to encourage a repair matrix. The techniques and their pitfalls are reviewed and discussed, and suggestions made as to the direction of future studies for the repair of osteochondral lesions in the painful knee.     

Partial cytochrome oxidase deficiency without subsarcolemmal accumulation of mitochondria in chronic progressive external ophthalmoplegia

Chronic progressive external ophthalmoplegia (CPEO) associated with proximal myopathy and/or craniosomatic abnormalities is a rare syndrome in which morphological mitochondrial changes have been found in some fibres (subsarcolemmal accumulation of mitochondria or "ragged red" fibres). We report a 14-year-old boy with CPEO and a mild proximal myopathy without these characteristic "ragged red" fibres. Histochemistry of skeletal muscle showed a mosaic of fibres without detectable cytochrome oxidase activity, while other mitochondrial enzymes were normal. The total cytochrome oxidase activity and cytochrome aa3 concentration in muscle mitochondrial fractions were only 40% of normal. This case is unique in that a biochemical defect was not accompanied by morphological abnormalities and may represent an early stage of CPEO before the development of morphological changes, or alternatively, a new variant of the disease.