Victimization over the life span: a comparison of lesbian, gay, bisexual, and heterosexual siblings

Lifetime victimization was examined in a primarily European American sample that comprised 557 lesbian/gay, 163 bisexual, and 525 heterosexual adults. Lesbian, gay, and bisexual (LGB) participants were recruited via LGB e-mail lists, periodicals, and organizations; these participants recruited 1 or more siblings for participation in the study (81% heterosexual, 19% LGB). In hierarchical linear modeling analyses, sexual orientation was a significant predictor of most of the victimization variables. Compared with heterosexual participants, LGB participants reported more childhood psychological and physical abuse by parents or caretakers, more childhood sexual abuse, more partner psychological and physical victimization in adulthood, and more sexual assault experiences in adulthood. Sexual orientation differences in sexual victimization were greater among men than among women.     

Controlled ovulation of the dominant follicle: a critical role for LH in the late follicular phase of the menstrual cycle

BACKGROUND: A method was sought to control ovulation of the dominant follicle and to test the importance of LH during the late follicular phase of the menstrual cycle. Menstrual cycles of rhesus monkeys were monitored, and treatment initiated at the late follicular phase (after dominant follicle selection, before ovulation). METHODS: The 2-day treatment consisted of GnRH antagonist plus either r-hFSH and r-hLH (1:1 or 2:1 dose ratio) or r-hFSH alone. In addition, half of the females received an ovulatory bolus of hCG. RESULTS: When treatment was initiated at estradiol levels >120 pg/ml, neither the endogenous LH surge, ovulation nor luteal function were controlled. However, when treatment was initiated at estradiol levels 80-120 pg/ml using either 1:1 or 2:1 dose ratios of FSH:LH, the LH surge was prevented, and ovulation occurred following hCG treatment. FSH-only treatment also prevented the LH surge, but follicle development appeared abnormal, and hCG failed to stimulate ovulation. CONCLUSIONS: Control over the naturally dominant follicle is possible during the late follicular phase using an abbreviated GnRH antagonist, FSH+LH protocol. This method offers a model to investigate periovulatory events and their regulation by gonadotrophins/local factors during the natural menstrual cycle in primates.     

Transstadial transfer of West Nile virus by three species of ixodid ticks (Acari: Ixodidae)

Larvae and/or nymphs of four species of ixodid ticks, Ixodes scapularis Say, Amblyomma americanum (L.), Dermacentor andersoni Stiles, and Dermacentor variabilis Say, were fed to completion on laboratory hamsters or mice which had been inoculated with a West Nile (WN) virus isolate from Culex pipiens L. captured in Connecticut USA. Maximum titers in mice and hamsters were approximately 5 and two logs, respectively, lower than recorded (10 logs) in a naturally infected American crow, Corvus brachyrhynchos Brehm. WN virus was isolated in Vero cell culture from ticks and detected by TaqMan RT-polymerase chain reaction (PCR) in ticks that had completed their feeding as larvae or nymphs, and in I. scapularis, D. andersoni, and D. variabilis that had molted into the next stage of development. Naive hosts, fed upon by nymphs that as larvae had fed on viremic hosts, did not become infected. WN virus was isolated in Vero cell culture from one female I. scapularis and was detected by TaqMan RT-PCR in 24 adult I. scapularis, one D. andersoni, and two D. variabilis adults that had fed to completion as larvae on viremic hosts and as nymphs on naive mice or hamsters. Three species of ixodid ticks acquired WN virus from viremic hosts and transstadially passed the virus, but vector competency was not demonstrated.     

Functions of the nucleus of the optic tract (NOT).

We studied the role of the nucleus of the optic tract (NOT) in adapting the gain of the angular vestibulo-ocular reflex (aVOR) in rhesus and cynomolgus monkeys using lesions and temporary inactivation with muscimol. The aVOR gain was adaptively reduced by forced sinusoidal rotation (0.25 Hz, 60 degrees/s) in a self-stationary visual surround, i.e., a visual surround that moved with the subject, or by wearing x0.5 reducing lenses during natural head movements. The aVOR gains dropped by 20-30% after 2 h and by about 30% after 4 h. Muscimol injections caused a loss of adaptation of contraversive-eye velocities induced by the aVOR, and their gains promptly returned to or above preadapted levels. The gains of the adapted ipsiversive and vertical eye velocities produced by the aVOR were unaffected by muscimol injections. Lesions of NOT significantly reduced or abolished the animals' ability to adapt the gain of contraversive aVOR-induced eye velocities, and the monkeys were unable to suppress these contraversive-eye velocities in a self-stationary surround. The lesions did not affect ipsiversive aVOR-induced eye velocities, and the animals were still able to suppress them. Lesions of NOT also affected the unadapted or "default" aVOR gains. After unilateral NOT lesions, gains of ipsiversive aVOR-induced eye velocity were reduced, while gains of contraversive aVOR-induced eye velocity were either unaffected or slightly increased. Consistent with this, muscimol injections into the NOT of unadapted monkeys slightly reduced the gains of ipsiversive and increased the gains of contraversive-eye velocities by about 8-10%. We conclude that each NOT processes ipsiversive retinal-slip information about visual surround movement relative to the head induced by the aVOR. In the presence of visual surround movement, the retinal-slip signal is suppressed, leading to adaptive changes in the gain of aVOR-induced contraversive horizontal eye velocities. NOT also has a role in controlling and maintaining the current state of the aVOR gains. Thus, it plays a unique role in producing and supporting adaptation of the gain of the horizontal aVOR that is likely to be important for stabilizing gaze during head movement. Pathways through the inferior olive are presumably important for this adaptation.     

Compensatory and orienting eye movements induced by off-vertical axis rotation (OVAR) in monkeys

Nystagmus induced by off-vertical axis rotation (OVAR) about a head yaw axis is composed of a yaw bias velocity and modulations in eye position and velocity as the head changes orientation relative to gravity. The bias velocity is dependent on the tilt of the rotational axis relative to gravity and angular head velocity. For axis tilts <15 degrees, bias velocities increased monotonically with increases in the magnitude of the projected gravity vector onto the horizontal plane of the head. For tilts of 15-90 degrees, bias velocity was independent of tilt angle, increasing linearly as a function of head velocity with gains of 0.7-0.8, up to the saturation level of velocity storage. Asymmetries in OVAR bias velocity and asymmetries in the dominant time constant of the angular vestibuloocular reflex (aVOR) covaried and both were reduced by administration of baclofen, a GABA(B) agonist. Modulations in pitch and roll eye positions were in phase with nose-down and side-down head positions, respectively. Changes in roll eye position were produced mainly by slow movements, whereas vertical eye position changes were characterized by slow eye movements and saccades. Oscillations in vertical and roll eye velocities led their respective position changes by approximately 90 degrees, close to an ideal differentiation, suggesting that these modulations were due to activation of the orienting component of the linear vestibuloocular reflex (lVOR). The beating field of the horizontal nystagmus shifted the eyes 6.3 degrees /g toward gravity in side down position, similar to the deviations observed during static roll tilt (7.0 degrees /g). This demonstrates that the eyes also orient to gravity in yaw. Phases of horizontal eye velocity clustered ~180 degrees relative to the modulation in beating field and were not simply differentiations of changes in eye position. Contributions of orientating and compensatory components of the lVOR to the modulation of eye position and velocity were modeled using three components: a novel direct otolith-oculomotor orientation, orientation-based velocity modulation, and changes in velocity storage time constants with head position re gravity. Time constants were obtained from optokinetic after-nystagmus, a direct representation of velocity storage. When the orienting lVOR was combined with models of the compensatory lVOR and velocity estimator from sequential otolith activation to generate the bias component, the model accurately predicted eye position and velocity in three dimensions. These data support the postulates that OVAR generates compensatory eye velocity through activation of velocity storage and that oscillatory components arise predominantly through lVOR orientation mechanisms.     

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.     

Characterization of unusual bacteria isolated from respiratory secretions of cystic fibrosis patients and description of Inquilinus limosus gen. nov., sp. nov

Using a polyphasic approach (including cellular protein and fatty acid analysis, biochemical characterization, 16S ribosomal DNA sequencing, and DNA-DNA hybridizations), we characterized 51 bacterial isolates recovered from respiratory secretions of cystic fibrosis (CF) patients. Our analyses showed that 24 isolates belong to taxa that have so far not (or only rarely) been reported from CF patients. These taxa include Acinetobacter sp., Bordetella hinzii, Burkholderia fungorum, Comamonas testosteroni, Chryseobacterium sp., Herbaspirillum sp., Moraxella osloensis, Pandoraea genomospecies 4, Ralstonia gilardii, Ralstonia mannitolilytica, Rhizobium radiobacter, and Xanthomonas sp. In addition, one isolate most likely represents a novel Ralstonia species, whereas nine isolates belong to novel taxa within the alpha-PROTEOBACTERIA: Eight of these latter isolates are classified into the novel genus Inquilinus gen. nov. as Inquilinus limosus gen. nov., sp. nov., or as Inquilinus sp. The remaining 17 isolates are characterized as members of the family ENTEROBACTERIACEAE: The recovery of these species suggests that the CF lung is an ecological niche capable of supporting the growth of a wide variety of bacteria rarely seen in clinical samples. Elucidation of the factors that account for the association between these unusual species and the respiratory tract of CF patients may provide important insights into the pathophysiology of CF infection. Because accurate identification of these organisms in the clinical microbiology laboratory may be problematic, the present study highlights the utility of reference laboratories capable of identifying unusual species recovered from CF sputum.     

Membrane ionic currents and properties of freshly dissociated rat brainstem neurons

It is well known that neuronal firing properties are determined by synaptic inputs and inherent membrane functions such as specific ionic currents. To characterize the ionic currents of brainstem cardio-respiratory neurons, cells from the hypoglossal (XII) nucleus and the dorsal motor nucleus of the vagus (DMX) were freshly dissociated and membrane ionic currents were studied under whole-cell voltage and current clamp. Both of these neurons showed a TTX-sensitive Na⁺ current with a much larger current density in XII than DMX neurons. This Na⁺ current had two (fast and slow) distinct inactivation decay components. The ratio of the magnitudes of the fast to slow component was roughly two-fold greater in DMX than in XII cells. Both DMX and XII neurons also showed a high voltage-activated Ca²⁺ current, but this current density was significantly greater (three-fold) in DMX than XII neurons. A relatively small amount of low-voltage activated Ca²⁺ current was also observed in DMX neurons, but not in the majority of XII cells. A transient and a sustained outward current components were observed in DMX cells, but only sustained currents were present in XII neurons. These outward currents had a reversal potential of about − 70 mV with 3 mM external K⁺ and −30 mV with 25 mM K⁺, and substitution of K⁺ with cesium and tetraethylammonium suppressed more than 90% the outward currents, indicating that most outward currents were carried by K⁺. The transient outward current consisted of two components with onesensitive to 4-aminopyridine and the other to intracellular Ca²⁺. In XII neurons, BRL 38227 (lemakalim), an ATP-sensitive K⁺ (K_ATP) channel activator, increased the sustained K⁺ currents by 10% of control, and glibenclamide, a K_ATP channel blocker, decreased the sustained K⁺ currents by 20%. Evidence for the presence of an inward rectifier K⁺ current was also obtained from both XII and DMX neurons. These results on XII and DMX neurons indicate that (1) the methods used to dissociate neurons provide a useful means to overcome voltage clamp technical difficulties; (2) ion channel characteristics such as density and biophysical properties of DMX neurons are very different from those of XII neurons; and (3) several newly discovered membrane ionic currents are present in these cells.     

Biolistic nuclear transformation of Saccharomyces cerevisiae and other fungi

Summary The yeast Saccharomyces cerevisiae has been engineered to synthesize and secrete desulfato-hirudin (hirudin), a thrombin inhibitor from the leech Hirudo medicinalis. The synthetic gene coding for hirudin was expressed constitutively under the control of four size-variants of the yeast glyceraldehyde-3-phosphate dehydrogenase promoter (GAP) and cloned into a 2 based multicopy yeast vector. The constitutive action of the four promoter variants was confirmed by demonstrating that the expression and secretion of hirudin is growth-related. The different efficiencies of the promoter variants not only affected hirudin expression but also led to changes in several cellular parameters, such as cell growth, average plasmid copy number and plasmid stability. The observed changes show that yeast cells establish a specific equilibrium for each promoter variant. We conclude, that the adjustment of cellular parameters in response to the expression levels of a heterologous protein is regulated by two counteracting selective forces: (1) the need for complementation of the auxotrophic host marker by the plasmid-encoded selection gene which, in the case of dLEU2, requires several plasmid copies; and (2) a selective advantage of cells with a lower copy number enabling them to escape the burden of heterologous protein production.     

Ornithine decarboxylase and polyamines in developing rat brain and heart: Effects of perinatal hypothyroidism

Hypothyroidism induced by perinatal administration of propylthiouracil (PTU) had profound effects on growth of the heart, with major organ weight deficits persisting well beyond the termination of drug treatment. These effects were preceded by disruption of the developmental patterns of cardiac ornithine decarboxylase (ODC) and the polyamines, which are thought to be intracellular modulators of cellular maturation. Activity of cardiac ODC was depressed in the PTU-treated group and putrescine and spermidine levels were markedly subnormal. PTU administration also affected brain growth, but much less so than in the heart. The disruption of the brain ODC/polyamine system was also less pronounced, with relatively small degrees of spermidine depletion and a slight elevation of ODC. For both tissues, the biochemical effects of perinatal hypothyroidism were opposite to those found previously for administration of exogenous thyroid hormones. These results support the views that:

1. (1) endogenous thyroid hormones contribute to the maintenance of normal developmental patterns of ODC and the polyamines, and

2. (2) the ODC/polyamine system participates in events modulating subsequent tissue growth.