Cell fate specification and symmetrical/asymmetrical divisions in the developing cerebral cortex

Two different modes of cell division are adopted by progenitor cells to generate the neurons and glia of the cerebral cortex: they either divide symmetrically to generate other progenitors or a pair of postmitotic cells or divide asymmetrically to generate both a progenitor and a postmitotic cell. In this study we used a lineage marker, the BAG retrovirus, in embryonic day 16 rats in combination with bromodeoxyuridine (BrdU) to identify patterns of cell generation in the cerebral cortex, and investigated the relationship between the phenotype of cells and the history of their lineages. The location, phenotype and birth order of clonally related cells were studied in the subsequent 3 weeks. Only pyramidal neurons and/or astrocytes formed discrete clusters in which several generations of family members were present, whereas nonpyramidal neurons were found exclusively in pairs or as single cells. Analysis of BrdU levels in these cells showed that nonpyramidal neurons were originally part of larger clones and were found dispersed in the neocortex because of tangential migration of their progenitors, dispersion of postmitotic cells, or death of clonal relatives. These results suggest that both symmetrical and asymmetrical division can be adopted by progenitor cells to generate cortical neurons and glial cells and that cell extrinsic events contribute to the isolation of nonpyramidal neurons.

Aspects of perinatal psychiatric illness

BACKGROUND

In view of the current changes in the National Health Service, it was considered an opportune time to review the literature on perinatal psychiatric illness.

METHOD

A systematic review was undertaken of relevant articles on MEDLINE, ClinPsych and Excerpta Medica Psychiatry.

RESULTS

Sixty-eight articles were used in the review.

CONCLUSIONS

Developments in the field of perinatal psychiatry include a greater understanding of the nosology and aetiology of the conditions, the effect of maternal illness on the child, as well as transcultural factors. The perspective of the individual sufferer has been somewhat ignored. New treatments with both pharmacotherapy and hormones are emerging, but perhaps the greatest current challenge is to adapt our management strategies to community care.

Preproricin expressed in Nicotiana tabacum cells in vitro is fully processed and biologically active

Ricin, the highly toxic glycoprotein expressed in the endosperm of castor seeds, is composed of a galactose-binding lectin B chain (RTB) disulfide linked to a RNA N-glycosidase A chain (RTA). Chemically modified ricin has been conjugated to monoclonal antibodies and used for targeted therapy of cancer and autoimmune diseases. Replacement of chemically coupled molecules with a genetically engineered targeted ricin would improve homogeneity and yield and permit structural changes in the fusion toxin to be introduced readily by oligonucleotide-directed mutagenesis. Previous methods of expression of ricin fusion proteins have been limited to expression of RTA or RTB moieties alone or expression of incompletely processed toxin in Xenopus laevis oocytes. In the present study, we introduced the cDNA encoding preproricin into cultured tobacco cells via Agrobacterium tumefaciens-mediated gene transfer. Yields of ricin in soluble cell extracts were 1 microg/g in cells or, approximately, 0.1% of the total soluble protein. The ricin was partially purified by P2 monoclonal antibody anti-RTB affinity chromatography. The RTA and RTB immunoreactive material migrated on SDS-PAGE at 65 kDa under nonreducing conditions and at 32-35 kDa under reducing conditions. The tobacco ricin bound to immobilized asialofetuin as avidly as castor bean ricin, suggesting intact sugar binding. Tobacco ricin inhibited rabbit reticulocyte lysate protein translation similar to castor bean ricin (IC50 of 3 x 10(-12) M for tobacco ricin and 1 x 10(-11) M for castor bean ricin). The human cutaneous T cell lymphoma cell line HUT102 showed similar sensitivity to tobacco ricin when compared to castor bean ricin (IC50 = 9 x 10(-13) and 2 x 10(-12) M, respectively). The efficiency of gene transfer, reasonable levels of expression, and full post-translational processing indicate that this expression system is suitable for production of ricin fusion toxins for therapeutic applications.

The clinical spectrum of postpartum thyroid disease

The clinical and biochemical features of postpartum thyroid disease were analysed in 152 antithyroid peroxidase antibody-positive (anti-TPO+ve) women and compared with 239 anti-TPO-ve age-matched control postpartum women. All were assessed monthly for up to 12 months postpartum. Seventy three anti-TPO+ve women developed postpartum thyroiditis (PPT): 19.2% hyperthyroid alone, 49.3% hypothyroid alone, and 31.5% characterized by hyper- followed by hypothyroidism. None of the antibody-negative women developed any thyroid dysfunction. A significant increase in many of eleven symptoms of hypothyroidism and some of eight symptoms of hyperthyroidism compared to control women was observed in all anti-TPO+ve women, independent of thyroid status. This was particularly seen in women who later developed PPT when they were euthyroid, but was also observed in euthyroid anti-TPO+ve women who showed no decline of thyroid function during the postpartum period. Although PPT is usually transient, this condition, and the euthyroid antibody-positive state, may be associated with significant symptomatology, including an increased incidence of minor to moderate depression. Early recognition of this syndrome by antenatal screening of thyroid antibodies may contribute to improved management of women during the postpartum period.

Cardiff puerperal mood and hormone study. III. Postnatal depression at 5 to 6 weeks postpartum, and its hormonal correlates across the peripartum period

BACKGROUND

We assessed associations of mood at 5-6 weeks postpartum with peripartum saliva cortisol and progesterone profiles.

METHOD

A prospective study involved 120 primiparous women free of major marital, socioeconomic and health problems, who collected saliva twice daily from 2 weeks before delivery to day 35 postpartum. This allowed intensive characterisation of cortisol and progesterone profiles. At the conclusion of the study, mood was assessed according to standard criteria.

RESULTS

Seven women developed major depression according to DSM-III-R criteria. No associations emerged between progesterone and mood at 5 to 6 weeks. Lower levels of evening cortisol in the immediate peripartum period, were associated with postnatal depression.

CONCLUSION

The study provides no support for the treatment strategy of progesterone augmentation following delivery, as a prophylactic against postnatal depression. The HPA axis and its associations with postnatal mood warrants further investigation.

Preoperative endovascular embolization of craniospinal hemangioblastomas

PURPOSE

To determine whether hemangioblastomas, highly vascular tumors requiring surgery that is potentially complicated by excessive bleeding, can be embolized safely by using interventional techniques that furnish a more avascular surgical field.

METHODS

Nine hemangioblastomas involving either the cerebellum or the spinal cord were embolized preoperatively. In each case the feeding artery was selectively catheterized with a microcatheter and the hypervascular tumor nidus was devascularized with polyvinyl alcohol particles.

RESULTS

Two patients who had undergone recent attempts as surgical resection at another institution had repeat surgery after endovascular embolization rendered the tumor nidus avascular. At surgery, the tumor was completely removed in one case and markedly debulked in the other. In all nine cases, blood loss after embolization was reported to be less than expected by experienced surgeons. In addition, manipulation and removal of the tumor was reported to be subjectively easier in these embolized tumors. The embolization procedure caused no permanent complications; however, one patient with a posterior fossa hemangioblastoma and hydrocephalus worsened clinically within 12 hours of embolization. This event was thought to be caused by obstructive hydrocephalus resulting from tumor swelling. Emergency craniotomy, ventricular decompression, and surgical resection of the tumor produced complete resolution of the signs and symptoms.

CONCLUSIONS

Our results indicate that preoperative embolization of hemangioblastomas is a safe procedure that is useful in aiding surgical resection of these highly vascular tumors.

Synthesis of novel imidazobenzodiazepines as probes of the pharmacophore for "diazepam-insensitive" GABAA receptors

The syntheses of a series of novel imidazobenzodiazepines and their affinities for diazepam sensitive (DS) and diazepam insensitive (DI) GABAA receptors are described. Imidazobenzodiazepines belong to one of the very few chemical families which exhibit high to moderate potency for DI GABAA receptors. Although imidazobenzodiazepines such as Ro 15-4513, 20, are the most potent DI GABAA receptor ligands described to date, their selectivity for DI versus DS GABAA receptors is only marginal. Previous structure-activity relationship (SAR) studies of imidazobenzodiazepines have indicated that the 3- and 8-positions are critical for high-affinity binding to DI GABAA receptors (J. Med. Chem. 1993, 36, 479-490. J. Med. Chem. 1993, 36, 1001-1006. J. Med. Chem. 1993, 36, 1820-1830). In order to determine why the ester function is critical to high affinity at the DI site, we have synthesized several derivatives which have substituents other than an ester at the C(3) position including 3-alkyl-, 3-alkylketo-, 3-alkyl ether, and 3-dialkylamino-substituted imidazobenzodiazepines. The SAR analysis of these compounds when combined with that of several pyrazoloquinolinones indicates that interactions at H1 and L1 as well as interactions at H2 anti to the imidazole N(2) and at a lipophilic pocket (labeled LDi) about the 3-position are required in order for imidazobenzodiazepines to exhibit selectivity and high affinity for DI GABAA receptors. Furthermore, the imidazobenzodiazepines substituted with an electron-donating group (alkoxy function) at position 8 revealed that the change of the substituent at C(8) from an electron-withdrawing to a donating function did not substantially alter either ligand affinity or selectivity for DI GABAA receptors. Thus, a pharmacophore is proposed for DI GABAA receptor ligands, which is characterized by the requirement of a lipophilic pocket LDi about the C(3) position of imidazobenzodiazepines. Using this model, two pyrazoloquinolinone derivatives were designed and synthesized. Their affinities and selectivities for DI GABAA receptors are consistent with those predicted by the DI GABAA receptor pharmacophore. In addition, examination of the in vitro binding data of 3-alkyl ether analogs confirms that the anti conformation of the ester group at the C(3) position of imidazobenzodiazepines (Ro15-4513, 20 series) is preferred at both DI and DS GABAA receptors. This constitutes the first evidence (other than molecular modeling) to support the auxillary involvement of H2 at the DI site and is important with regard to the synthesis of other DI GABAA receptor selective ligands in the future.(ABSTRACT TRUNCATED AT 400 WORDS)

Human fiber size and enzymatic properties after 5 and 11 days of spaceflight

Biopsies from the vastus lateralis muscle were obtained from three astronauts before and after two 5-day flights and from five astronauts before and after one 11-day flight (space shuttle flights: STS-32, -33, and -34). Muscle fibers from two separate samples from each biopsy were classified as type I and II or as type I, IIA, and IIB by using qualitative myofibrillar adenosinetriphosphatase (ATPase) staining. Cross-sectional area (CSA), number of capillaries per fiber, and the activities of succinate dehydrogenase (SDH), alpha-glycerophosphate dehydrogenase (GPD), and myofibrillar ATPase were determined from one sample of fibers of each myofibrillar ATPase type. Postflight biopsies had 6-8% fewer type I fibers than preflight. Mean fiber CSAs were 16-36% smaller after the 11-day flight with the relative effect being type IIB > IIA > I. Mean fiber CSAs were 11 and 24% smaller in type I and II fibers after 5 days of flight. Myofibrillar ATPase activities increased in type II but not in type I fibers after flight, whereas SDH activity was unaffected in either fast or slow fibers. GPD activity in type I fibers was approximately 80% higher (P > 0.05) postflight compared with preflight. Myofibrillar ATPase/SDH ratios in type II fibers were higher after than before flight, suggesting that some fast fibers were more susceptible to fatigue after flight. The GPD/SDH ratios were elevated in some type I fibers after spaceflight. The number of capillaries per fiber was 24% lower after than before flight, whereas the number of capillaries per unit CSA of muscle tissue was unchanged. These data suggest that adaptations in the size, metabolic properties, and vascularity of muscle fibers can occur rapidly in the space environment. These adaptations were qualitatively similar to those observed in animals after actual or simulated spaceflight conditions for short periods.

Cognitive function, thyroid status and postpartum depression

Impairment of cognitive function can occur with thyroid disorder and also with depression. Since depression occurs in conjunction with postpartum autoimmune thyroiditis, the question arises as to whether any impairment of cognitive function in postpartum women is related to change in thyroid status or to depressed mood. A total of 242 women (110 thyroid antibody-positive and 132 antibody-negative) were assessed at 8, 12, 20 and 28 weeks postpartum in the outpatients of a district general hospital. Thyroid antibody levels (antimicrosomal and antithyroglobulin) were monitored at monthly intervals, together with plasma T3, T4 and thyroid-stimulating hormone. The main outcome measures were Research Diagnostic Criteria for depression, the 17-item Hamilton Depression Rating Scale and the Edinburgh Postnatal Depression Scale, together with reaction time and digit span. Subjects with postnatal depression showed detectable cognitive impairment independent of thyroid antibody status and actual thyroid dysfunction.

Effects of varying forage types on milk production responses to whole cottonseed, tallow, and yeast

Four forage treatments (45% corn silage, 33.75% corn silage plus 11.25% alfalfa hay, 11.25% bermudagrass hay, or 11.25% cottonseed hulls on a DM basis) were arranged factorially with no added fat, 12.5% whole cottonseed, or 2.5% tallow. Different diets were fed during three 28-d periods to 20 control Holstein cows and to 20 cows receiving yeast continuously in a split-plot design. Milk yield of cows fed cottonseed hulls with corn silage was 2.4 kg/d higher than with corn silage plus bermudagrass hay and .7 kg/d higher than with corn silage only or corn silage plus alfalfa hay. Whole cottonseed depressed milk yield by 1 kg/d. Cows fed yeast had increased DMI, and yeast interacted with forage so that more milk was produced by cows fed alfalfa diets. Yeast depressed milk protein percentage. Holstein cows in a commercial Florida dairy were fed no yeast or 10 g/d continuously for 60 d; milk fat percentage was greater (3.51 vs. 3.37%) with yeast. In summary, effects on milk and SCM were positive when cottonseed hulls were utilized with corn silage, negative with whole cottonseed, and neutral with supplemental tallow. Yeast effects on SCM, although not significant for either experiment, tended to be positive for both (mean +1.2 kg/d per cow).

Effects of variable sources of distillers dried grains plus solubles on milk yield and composition

This study compared diets supplemented with distillers dried grains plus solubles originating from whiskey distilling with those from fuel alcohol production or soybean meal. Forty-eight cows in mid and early lactation were offered a different dietary treatment in each of three 28-d periods. Dietary design included three supplements at 14 or 18% CP of dietary DM, with or without blood meal. Additionally, a third, darker, fuel ethanol source was added at 14 and 18% CP without blood meal during period 3 to incorporate greater variation in quality of distillers grains. No detectable differences occurred in DMI or in any variables because of blood meal. Milk yield was higher when cows were fed diets at 18% rather than at 14% CP. Cows fed the two lighter distillers grains diets yielded .8 kg/d more milk than cows fed soybean meal diets, and cows fed whiskey distillers grains yielded 1.3 kg/d more SCM than cows fed diets with darkest distillers grains. Milk protein percentage was depressed when the darkest distillers grains were fed. Distillers dried grains plus solubles can provide an excellent substitute for soybean meal and corn in dairy cow diets.

On time delay estimation of epileptic EEG

The present study deals with comparative evaluation of various methods for time delay estimations applied to multichannel seizure EEG. The different methods included block algorithms, both in time and frequency domains (such as General Crosscorrelation, FFT, AR), and a new method for time delay estimation based on adaptive least-squares filtering. The various time delay estimators were tested on simulated signals and on real multichannel EEG recorded from rats having generalized seizures with focal onset. The adaptive least-squares filtering (the lattice-ladder type) has been found as the most efficient for time delay estimation.

Health, height, and history: an overview of recent developments in anthropometric history

This paper examines some of the major developments in the field of anthropometric history since the end of the 1970s. The first two sections of the paper consider the conceptual basis of anthropometric history and the relationship between height and the standard of living. Sections 3-7 discuss the contributions made by anthropometric historians to our understanding of the social and economic history of the United States, the history of American slavery, the social history of the United Kingdom, the origins of Habsburg industrialization, and the standard of living in nineteenth-century Sweden. The concluding section summarizes the impact of anthropometric history and identifies a number of areas for further research.

Inhibition of [3H]isradipine binding to L-type calcium channels by the optical isomers of isoflurane. Lack of stereospecificity

BACKGROUND

The dose-dependent myocardial depression of volatile general anesthetics such as isoflurane has been linked to blockade of L-type Ca2+ channels. The effects of (+)- and (-)-isoflurane on the inhibition of [3H]isradipine binding to L-type Ca2+ channels in membranes prepared from mouse heart were examined. In addition, because there is a stereo-specific effect of these isomers on sleep time in mice, the potential contribution of L-type Ca2+ channels to isoflurane-induced sleep was assessed by determining whether a similar stereoselectivity would be manifested at these sites in cerebral cortical membranes.

METHODS

The effects of isoflurane stereoisomers on the binding of an L-type Ca2+ channel ligand ([3H]isradipine) were studied in cardiac and brain cortical membranes. Their potencies and effects on the Kd and Bmax of [3H]isradipine were measured.

RESULTS

Pharmacologically relevant concentrations of (+)- and (-)-isoflurane inhibited [3H]isradipine binding. The IC50 values for (+)-isoflurane were 0.48 +/- 0.02% and 0.40 +/- 0.01% in heart and brain membranes, respectively. The values for (-)-isoflurane were not significantly different from the respective values for the (+)-isomer. Saturation analysis demonstrated (+)- and (-)-isoflurane inhibited [3H]isradipine binding by significantly reducing Bmax and increasing Kd, but there were no significant differences between these isomers in either tissue.

CONCLUSIONS

The stereoisomers of isoflurane are equipotent as inhibitors of [3H]isradipine binding to L-type Ca2+ channels. This lack of stereoselectivity between (+)- and (-)-isoflurane indicates that the [3H]isradipine site on L-type Ca2+ channels in brain does not contribute to the differences in isoflurane-induced sleep time reported for these stereoisomers. Taken with a lack of stereoselectivity at L-type Ca2+ channels in heart, an optically resolved isomer of isoflurane may have clinical advantages compared to the current racemic mixture.

5-Hydroxytryptamine1A receptor synthetic peptides. Mechanisms of adenylyl cyclase inhibition

The 5-hydroxytryptamine1A receptor (5-HT1AR) is a G-protein-coupled receptor negatively coupled to adenylyl cyclase (AC). We have studied the functional domains of 5-HT1AR using synthetic peptides to block or mimic receptor function. The entire second intracellular loop (5-HT1AR-i2) and the carboxyl end of the third intracellular loop (5-HT1AR-i3-C) strongly inhibited forskolin-stimulated AC activity. These effects were not additive with those of 5-HT. Like 5-HT, the peptides 5-HT1AR-i3-C and -i2 weakly inhibited AIF4- and Mn2+ stimulated AC activity. 5-HT1AR binding assays indicated that peptides could interact with the same G-protein pool as the 5-HT1AR. 5-HT1AR-i3-C- and -i2-stimulated [35S]guanosine 5'-O-(thiotriphosphate) binding on Go/Gi proteins. Only 5-HT1AR-i3-C partially adopted an alpha-helical conformation in solution. These data show that different domains in the 5-HT1AR second and third intracellular loops can couple to and activate Gi proteins in order to mediate AC inhibition. Peptide-induced AC inhibition was not sensitive to pertussis toxin as opposed to the 5-HT1AR-mediated effect. Our data show that the 5-HT1AR and the 5-HT1AR peptides activate Gi proteins in a slightly different manner.

Reduction of Cr(VI) by a Consortium of Sulfate-Reducing Bacteria (SRB III)

A consortium of bacteria with tolerance to high concentrations of Cr(VI) (up to 2,500 ppm) and other toxic heavy metals has been obtained from metal-refinishing wastewaters in Chengdu, People's Republic of China. This consortium consists of a range of gram-positive and gram-negative rods and has the capacity to reduce Cr(VI) to Cr(III) as amorphous precipitates which are associated with the bacterial surfaces. An endospore-producing, gram-positive rod and a gram-negative rod accumulate the most metallic precipitates, and, over time, 80 to 95% of Cr can be removed from concentrations ranging from 50 to 2,000 ppm (0.96 to 38.45 mM). Kinetic studies revealed a first-order constant for Cr removal of 0.1518 h -1 for an initial concentration of 1,000 ppm (19.3 mM), and the sorption isothermal data could be interpreted by the Freundlich relationship. The sorption was not entirely due to a passive interaction with reactive sites on the bacterial surfaces since gamma-irradiated, killed cells could not immobilize as much metal. When U or Zn was added with the Cr, it was also removed and could even increase the total amount of Cr immobilized. The consortium was tolerant to small amounts of oxygen in the headspace of tubes, but active growth of the bacteria was a requirement for Cr immobilization through Cr(VI) reduction, resulting in the lowering of E h . Our data suggest that the reduction was via H 2 S. This consortium has been named SRB III, and it may be useful for the bioremediation of fluid metal-refining wastes.

Maternity blues and major endocrine changes: Cardiff puerperal mood and hormone study II

OBJECTIVES

To define relation between mood and concentrations of progesterone and cortisol during perinatal period to test hypothesis that rapid physiological withdrawal of steroid hormones after delivery is associated with depression.

DESIGN

Prospective study of primiparous women from two weeks before expected date of delivery to 35 days postpartum.

SETTING

Antenatal clinic in university hospital, obstetric inpatient unit, patients' homes.

SUBJECTS

120 of 156 primiparous women interviewed. Remainder excluded because of major marital, socioeconomic, or medical problems or because caesarean section required.

MAIN OUTCOME MEASURES

Concentrations of progesterone and cortisol in saliva samples; women's moods assessed by various scores for depression.

RESULTS

Changes in salivary progesterone and cortisol concentrations were similar to those already characterised for plasma. Peak mean score for maternity blues (5.3 on Stein scale) was on day five postpartum (P < 0.02 compared with mean scores on other postpartum days). High postpartum scores for maternity blues were associated with high antenatal progesterone concentrations on day before delivery (P < 0.05), with high rate of rise of antenatal progesterone concentrations (P < 0.05), with decreasing progesterone concentrations from day of delivery to day of peak blues score (P > or = 0.01), and with low progesterone concentrations on day of peak blues score (P < 0.01). Seventy eight women were designated as having maternity blues (peak score > or = 8 on Stein scale) while 39 had no blues. Women with blues had significantly higher antenatal progesterone concentrations and lower postnatal concentrations than women without blues (geometric mean progesterone concentrations: one day before delivery 3860 pmol/l v 3210 pmol/l respectively, P = 0.03; ten days postpartum 88 pmol/l v 114 pmol/l, P = 0.048). Cortisol concentrations were not significantly associated with mood.

CONCLUSION

Maternal mood in the days immediately after delivery is related to withdrawal of naturally occurring progesterone.

Synthesis of benzo-fused benzodiazepines employed as probes of the agonist pharmacophore of benzodiazepine receptors

The synthesis and in vitro evaluation of benzo-fused benzodiazepines 1-6 are described. These "molecular yardsticks" were employed to probe the spatial dimensions of the lipophilic pocket L2 in the benzodiazepine receptor (BzR) cleft and to determine the effect of occupation of L2 with respect to agonist activity. Of the new analogs synthesized, the 7,8-benzo-fused benzodiazepine 6 displayed moderately high affinity for the BzR (IC50 = 55 nM) and exhibited both anticonvulsant (ED50 approximately 15 mg/kg) and muscle relaxant (ED50 approximately 15 mg/kg) activity. As expected, 2 and 4 interacted with the repulsive regions of interaction, S1 and S2, and exhibited low affinities for BzR. The rigid nature of these molecular yardsticks (especially 6, Figure 7) has been employed to probe the depth of L2. Moreover, in the case of 6 full occupation of L2 has resulted in an increase in the muscle relaxant effect at the expense of the anticonvulsant/anxiolytic effect.

Effects of undegradable protein and supplemental fat on milk yield and composition and physiological responses of cows

Because some previous studies indicated that addition of dietary fat may delay milk yield response and that effects carry over after withdrawal, an objective of this reversal design with four 28-d periods was to estimate residual effects. Diets were fed 2 wk before period 1 to permit inclusion of pretreatment diet in the mathematical model and changed for each of 33 cows at the start of periods 1 through 3; period 4 treatments continued those for period 3. Diets were 50% corn silage supplemented to be 12% CP with soybean meal and urea; 15% CP with soybean meal, blood and soybean meals, or feather and soybean meals; and 18% CP with soybean meal or blood and soybean meals. Protein treatments were replicated in diets containing 2.0% Ca soaps of fatty acids. No carry-over effects were significant; however, yield increases from Ca soaps were not evident until wk 4. Diet CP had a positive linear effect on milk and SCM yields, BW, and blood urea N. Milk protein percentage was higher from soybean meal diets. Addition of dietary Ca soaps of fatty acids increased milk, protein, fat, and SCM yields. Milk protein percentage was depressed when Ca soaps of fatty acids were fed with blood meal but not with soybean meal. No positive responses were observed from increasing dietary undegradable protein with blood meal or feather meal.

HIV prevention in prisons and jails: obstacles and opportunities

High rates of human immunodeficiency virus (HIV) infection among jail and prison inmates suggest that HIV prevention efforts should focus on incarcerated populations. Overcrowding, the high prevalence of injection drug use, and other high-risk behaviors among inmates create a prime opportunity for public health officials to affect the course of the HIV epidemic if they can remedy these problems. Yet, along with the opportunity, there are certain obstacles that correctional institutions present to public health efforts. The various jurisdictions have differing approaches to HIV prevention and control. Whether testing should be mandatory or voluntary, whether housing should be integrated or segregated by HIV serostatus, and whether condoms, bleach, or clean needles should be made available to the prisoners, are questions hotly debated by public health and correctional officials. Even accurate assessment of risk-taking within the institutions leads to controversy, as asking questions could imply acceptance of the very behaviors correctional officials are trying to prevent. Education and risk-reduction counseling are the least controversial and most widely employed modes of prevention, but the effectiveness of current prevention efforts in reducing HIV transmission in this high-risk population is largely undetermined.

Lineage analysis reveals neurotransmitter (GABA or glutamate) but not calcium-binding protein homogeneity in clonally related cortical neurons

Studies of cell lineage in the rat cerebral cortex have provided new insights into the mechanisms of neuronal and glial determination. They have shown that clonally related cells, marked with retrovirus injection at embryonic day 16 (E16), express the same glial or neuronal phenotype, suggesting that separate progenitors for each of these cell phenotypes exist in the ventricular zone at that stage of corticogenesis. However, it is not known if such committed progenitors are present in the ventricular zone before E16. Another important question concerns which neurochemical features are shared by clonally related cells of the adult cerebral cortex. In this study we have addressed the first question by injecting a retroviral vector expressing beta-galactosidase into the telencephalic ventricles of rat embryos at different stages (E14-E19). In order to classify clonally related neurons in the cerebral cortex of these rats, we have used postembedding immunohistochemistry for the amino acid neurotransmitters glutamate, aspartate, and GABA. Glutamate and GABA immunoreactivity marked nonoverlapping populations of cells that corresponded to the pyramidal and nonpyramidal neuron types of the rat cerebral cortex. Clonally related neurons, marked by retrovirus injection at any day between E14 and E19, homogeneously expressed one or other phenotype and accordingly displayed glutamate or GABA immunoreactivity. This finding indicates that committed progenitor cells for pyramidal and nonpyramidal neurons are present in the ventricular zone before E16. To investigate whether lineage dictates other features in clonally related neurons, we performed an immunohistochemical analysis for the calcium-binding proteins calbindin, parvalbumin, and calretinin in clusters of clonally related nonpyramidal neurons. The same calcium-binding protein was rarely found in members of the same cluster, suggesting that lineage does not control the expression of calcium-binding proteins in cortical nonpyramidal neurons. As a result of examining a large number of clonally related neurons from brains injected at different ages, we observed remarkable differences in number and laminar distribution of pyramidal and nonpyramidal neurons marked with retrovirus. Clusters of nonpyramidal neurons were usually composed of two or three cells, and resided in the cortical layers that were just being generated at the time of injection. Clusters of pyramidal neurons were larger and dispersed in several layers in the earlier injections; their size and laminar distribution were progressively reduced for later injections. These observations suggest the existence of different mechanisms that generate the pyramidal and nonpyramidal neurons of the cerebral cortex.

The demographic impact of the First World War: an anthropometric perspective

During the 1970s and 1980s Jay Winter published a series of highly influential articles on the demographic impact of the First World War, culminating in his study of The Great War and the British People in 1986. Winter argued that the war led to a dramatic improvement in average living standards, and that the survival chances of most sections of the civilian population improved more rapidly than they might have done if peace had been maintained. This paper seeks to test the strength of Winter's hypothesis in three main ways. Section I examines the arguments which Winter himself put forward to support his view that the war led to a systematic erosion of pre-war differentials in infant mortality. Section III utilizes evidence relating to children's heights to examine the extent to which the war led to improvements in children's 'nutritional status'. The paper's overall conclusion is that the war did not lead to any dramatic improvements in civilian health; the overall impression to be gained from an analysis of wartime health statistics is one of continuity rather than change.

Mesenteric lymphadenitis depicted by indium 111-labeled white blood cell imaging

An acutely ill child with abdominal pain and concomitant pharyngitis often presents a diagnostic challenge. This report describes how indium 111-labeled white blood cell imaging helped to clarify the confusing case of a 4-year-old boy with fever, pharyngitis, and abdominal pain. The triad of abnormal white cell localization in the nasopharynx, cervical lymph nodes, and right lower abdominal quadrant supported the diagnosis of a systemic infection rather than appendicitis, abscess, or another surgical condition. Mesenteric lymphadenitis associated with systemic infection should be included in the differential diagnosis of abdominal pain in a child with this clinical presentation.

Demographic characteristics of retroviral infections (HIV-1, HIV-2, and HTLV-I) among female professional sex workers in Lagos, Nigeria

In 1990/1991, 885 prostitutes residing in 11 of the 12 Local Government Areas (LGAs) of Lagos State, Nigeria, participated in a cross-sectional study to determine current seroprevalence of antibodies to human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2), and human T-cell lymphotropic virus type I (HTLV-I). The overall prevalence of HIV-1 was 12.3%, of HIV-2, 2.1%, and of HTLV-I, 2.8%. HIV-1 seropositivity did not vary significantly by age, socioeconomic class, or nationality, but HIV-1 seroprevalence was significantly elevated for prostitutes resident in the Port area of Lagos which serves as a crossroads for international and national commerce (OR = 2.3; 95% CI = 1.1, 4.6). HIV-2 infection was significantly associated with low socioeconomic class (OR = 3.7; 95% CI = 1.2, 10.8) and non-Nigerian nationality (OR = 6.7; 95% CI = 2.5, 18.4). Prevalence of HTLV-I infection increased significantly with age (OR = 2.3; 95% CI = 1.0, 5.3). The high seroprevalence of HIV-1 in this survey, compared with previous surveys reported in the last several years and the correlation between high prevalence and areas of international commerce suggest that HIV-1 is spreading in this area of Nigeria. Intensified prevention campaigns are needed to address this possible emerging epidemic.

A hormonal component to postnatal depression

Disorders of the thyroid gland are associated with disorders of mood (Thomas et al, 1970; Van Uitert & Russakoff, 1979; Folks, 1984; Young, 1984; Jadresic, 1990). Both hypothyroid and hyperthyroid states can be associated with depression, which is sometimes accompanied by psychotic features such as delusions and hallucinations (Wilson & Jefferson, 1986). Similarly, primary affective disorders can be accompanied by changes in thyroid function, with low thyroid-stimulating hormone (TSH) levels and elevated thyroxine (T4) (Kirkegaard & Faber, 1980), and in major depressive illness there is often a blunted TSH response to thyrotrophin releasing hormone (TRH) (Prange et al, 1972; Loosen, 1987).

Neurochemical actions of inhalational anesthetics at the GABAA receptor complex

Pharmacologically relevant concentrations of inhalational anesthetics such as halothane, enflurane and isoflurane enhance [3H]flunitrazepam (FLU) binding to benzodiazepine receptors prepared from well-washed membranes of murine cerebral cortex and cerebellum. These effects were concentration dependent and markedly enhanced by addition of chloride to the incubation medium. Using halothane as a prototype inhalational agent, it was observed that like barbiturates, increases in [3H]FLU binding were effected through an increase apparent in the apparent affinity of this radioligand with no accompanying change in the maximum number of binding sites. Although previous reports have demonstrated barbiturates augment gamma-aminobutyric acid-enhanced [3H]benzodiazepine binding, halothane exerts an additive effect in the nominal absence of chloride. Isoflurane produces a significant reduction in the EC50 of pentobarbital-augmented [3H]FLU binding. Halothane modestly reduced the binding of a benzodiazepine receptor inverse agonist, [3H]Ro 15-4513. Significant differences were also observed in the potencies and efficacies of both isoflurane and enflurane to enhance [3H]FLU binding to benzodiazepine receptors in cerebellar and cortical membranes. These findings provide a possible molecular basis for the clinical observation that benzodiazepines and barbiturates augment the anesthetic properties of inhalational agents. Moreover, the regional differences in anesthetic potency and efficacy reported here suggest a differential interaction of these inhalational agents among gamma-aminobutyric acidA receptor isoforms.

Load concentrations around crystal aggregates in articular cartilage under short-term loading

The deposition of crystals in joints is a feature of a number of joint diseases. Crystals are frequently observed on the surface of articular cartilage and in the mid-zone. The purpose of this investigation was to model the stress concentrations in the mid-zone of the cartilage layer arising from the presence of large crystal aggregates. Scanning electron microscopy was used to determine the geometry and distribution of crystal aggregates within the cartilage layer. Finite element and photoelastic approaches were then used to predict the stress distribution around spherical aggregates 50 and 100 microns in diameter. The implication of the results is that very densely packed and tightly bound spherical aggregates will themselves carry a certain amount of load. However, less tightly packed aggregates, perhaps interspersed with fibrous tissue, are potentially much more damaging.

Wear of articular cartilage: the effect of crystals

An investigation of the effect of crystals in a lubricant on the wear of articular cartilage in vitro was carried out in order to examine the hypothesis that crystals present in synovial fluid could cause abrasive damage of the articular surface. Plugs of cartilage were worn against a stainless steel counterface in a pin-on-disc wear rig. The concentration of cartilage debris present in the lubricant was assessed by measuring the bound sulphate originating from the glycosaminoglycans by ion chromatography. Results indicated that the presence of crystals in the lubricant significantly increased the concentration of wear debris and that the crystal size and morphology influenced the type of damage sustained by the cartilage. Other experimental evidence suggested that cartilage scratched in vivo was no more susceptible to further in vitro damage in this experimental model than normal cartilage. These results implied that crystals present in the synovial fluid of arthritic joints have the potential to cause excessive wear of the articular surface, but that if such crystals are removed the scratched cartilage may not be susceptible to any further damage by abrasive wear.

Basal cell carcinoma arising in venous ulcers and mimicking granulation tissue

BACKGROUND

Basal cell carcinoma (BCC) arising in venous ulcers is rare, and its appearance in this setting is not fully recognized.

OBJECTIVE

The purpose of this report is to alert the clinician to the subtle clinical appearance of this tumor and to prompt a more rapid recognition.

METHODS

We report five cases of BCC arising in venous ulcers of the lower extremity that we have observed over a period of 6 years. In all cases the tumor was diagnosed histologically.

RESULTS

In all five cases the tumor had the appearance of seemingly healthy granulation tissue, which was often exuberant and translucent. The border of this apparent "granulation tissue" was rolled over the margins of the ulcer.

CONCLUSION

Basal cell carcinoma arising in venous ulcers often has the appearance of translucent granulation tissue that extends beyond the ulcer's margins. These clinical characteristics should alert the clinician to the need for obtaining a biopsy of the ulcer bed.

Cardiff puerperal mood and hormone study. 1. Saliva steroid hormone profiles in late pregnancy and the puerperium: endocrine factors and parturition

Participants were 120 primiparous women who had vaginal delivery of a non-handicapped child. Saliva was collected twice daily through parturition to day 35 post-partum. In the prepartum, a highly significant circadian rhythm was seen in cortisol, with a lower-amplitude rhythm in progesterone (AM/PM = 1.12). Evening samples showed a rise in cortisol, with a highly significant rise on day -1. The rise was small. The fall in progesterone in the 3 days before parturition was also small (approximately 6%). Neither change provides an obvious trigger for parturition.

Health services in the New England region and their relevance to Aboriginal people

Public hospitals provide the vast majority of available health services in rural areas of Australia. These services reflect their clinical European origins in terms of organisation and delivery. This is one reason why they remain largely foreign and irrelevant to Aboriginal people, who are reluctant users of the services and facilities available. In this article we examine what is being done in the New England region of New South Wales to improve the relevance of existing health services for Aboriginal people; this is an important first step in improving the third world health status which they presently endure.

Effects of concentration of dietary phosphorus on amount and route of excretion

Objectives were to determine the effect of dietary concentration of P in DM on routes of excretion of P and to evaluate direct and indirect measures of calculating DM digestibility and P excretion. Twelve lactating Holstein cows were fed 20 kg of DM containing .41% P daily for 4 wk and then were assigned randomly to one of three diets: low (.30%), medium (.41%), or high (.56%) in P for 9 wk. Total collections of excreta (feces and urine) and milk were made during wk 4, 7, 10, and 13. At wk 4, cows excreted 88.2% of P consumed daily: 68.6% of excreted P in feces, 1.0% in urine, and 30.3% secreted in milk. Cows assigned to the low P diet decreased intake by 26.8% and excretion of P in feces by 22.7% in wk 13 compared with wk 4, whereas cows fed the high P diet increased intake by 36.5% and excretion of P in feces by 48.6%. Digestibility of DM was 62.6% when calculated from total collection of feces but only 55.7 or 56.5% when estimated indirectly using Cr or acid detergent lignin as indigestible markers. Apparent excretion of P was less than that estimated using either of the marker techniques (49.7 vs. 59.1 and 58.1 +/- .7 g/d of P) because digestibility of DM was underestimated. A prediction equation was developed for P excretion based on P intake and milk production.

Salivary testosterone levels and major depressive illness in men

Studies of testosterone levels in patients with major depressive illness have produced varying results, plasma levels usually being reported. Saliva levels reflect 'free' plasma testosterone, and a pilot study of 11 men with major depression with melancholia, who underwent a standard dexamethasone suppression test, is described. There were no significant differences in testosterone levels compared with an age-matched control group. In the patient group, pre-dexamethasone levels correlated significantly and negatively with depression ratings on the 21-item Hamilton and the Montgomery and Asberg depression scales, and also with state anxiety measured on the Spielberger scale.