Single cell tracing of Pomc neurons reveals recruitment of 'Ghost' subtypes with atypical identity in a mouse model of obesity

The hypothalamus contains a remarkable diversity of neurons that orchestrate behavioural and metabolic outputs in a highly plastic manner. Neuronal diversity is key to enabling hypothalamic functions and, according to the neuroscience dogma, it is predetermined during embryonic life. Here, by combining lineage tracing of hypothalamic pro-opiomelanocortin (Pomc) neurons with single-cell profiling approaches in adult male mice, we uncovered subpopulations of 'Ghost' neurons endowed with atypical molecular and functional identity. Compared to 'classical' Pomc neurons, Ghost neurons exhibit negligible Pomc expression and are 'invisible' to available neuroanatomical approaches and promoter-based reporter mice for studying Pomc biology. Ghost neuron numbers augment in diet-induced obese mice, independent of neurogenesis or cell death, but weight loss can reverse this shift. Our work challenges the notion of fixed, developmentally programmed neuronal identities in the mature hypothalamus and highlight the ability of specialised neurons to reversibly adapt their functional identity to adult-onset obesogenic stimuli.

Monte Carlo simulations and phantom validation of low-dose radiotherapy to the lungs using an interventional radiology C-arm fluoroscope

PURPOSE

To use MC simulations and phantom measurements to investigate the dosimetry of a kilovoltage x-ray beam from an IR fluoroscope to deliver low-dose (0.3-1.0 Gy) radiotherapy to the lungs.

MATERIALS AND METHODS

PENELOPE was used to model a 125 kV, 5.94 mm Al HVL x-ray beam produced by a fluoroscope. The model was validated through depth-dose, in-plane/cross-plane profiles and absorbed dose at 2.5-, 5.1-, 10.2- and 15.2-cm depths against the measured beam in an acrylic phantom. CT images of an anthropomorphic phantom thorax/lungs were used to simulate 0.5 Gy dose distributions for PA, AP/PA, 3-field and 4-field treatments. DVHs were generated to assess the dose to the lungs and nearby organs. Gafchromic film was used to measure doses in the phantom exposed to PA and 4-field treatments, and compared to the MC simulations.

RESULTS

Depth-dose and profile results were within 3.2% and 7.8% of the MC data uncertainty, respectively, while dose gamma analysis ranged from 0.7 to 1.0. Mean dose to the lungs were 1.1-, 0.8-, 0.9-, and 0.8- Gy for the PA, AP/PA, 3-field, and 4-field after isodose normalization to cover ∼ 95% of each lung volume. Skin dose toxicity was highest for the PA and lowest for the 4-field, and both arrangements successfully delivered the treatment on the phantom. However, the dose distribution for the PA was highly non-uniform and produced skin doses up to 4 Gy. The dose distribution for the 4-field produced a uniform 0.6 Gy dose throughout the lungs, with a maximum dose of 0.73 Gy. The average percent difference between experimental and Monte Carlo values were -0.1% (range -3% to +4%) for the PA treatment and 0.3% (range -10.3% to +15.2%) for the 4-field treatment.

CONCLUSION

A 125 kV x-ray beam from an IR fluoroscope delivered through two or more fields can deliver an effective low-dose radiotherapy treatment to the lungs. The 4-field arrangement not only provides an effective treatment, but also significant dose sparing to healthy organs, including skin, compared to the PA treatment. Use of fluoroscopy appears to be a viable alternative to megavoltage radiation therapy equipment for delivering low-dose radiotherapy to the lungs.

Kisspeptin treatment induces gonadotropic responses and rescues ovulation in a subset of preclinical models and women with polycystic ovary syndrome

STUDY QUESTION

Can kisspeptin treatment induce gonadotrophin responses and ovulation in preclinical models and anovulatory women with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

Kisspeptin administration in some anovulatory preclinical models and women with PCOS can stimulate reproductive hormone secretion and ovulation, albeit with incomplete efficacy.

WHAT IS KNOWN ALREADY

PCOS is a prevalent, heterogeneous endocrine disorder, characterized by ovulatory dysfunction, hyperandrogenism and deregulated gonadotrophin secretion, in need of improved therapeutic options. Kisspeptins (encoded by Kiss1) are master regulators of the reproductive axis, acting mainly at GnRH neurons, with kisspeptins being an essential drive for gonadotrophin-driven ovarian follicular maturation and ovulation. Altered Kiss1 expression has been found in rodent models of PCOS, although the eventual pathophysiological role of kisspeptins in PCOS remains unknown.

STUDY DESIGN, SIZE, DURATION

Gonadotrophin and ovarian/ovulatory responses to kisspeptin-54 (KP-54) were evaluated in three preclinical models of PCOS, generated by androgen exposures at different developmental windows, and a pilot exploratory cohort of anovulatory women with PCOS.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Three models of PCOS were generated by exposure of female rats to androgens at different periods of development: PNA (prenatal androgenization; N = 20), NeNA (neonatal androgenization; N = 20) and PWA (post-weaning androgenization; N = 20). At adulthood (postnatal day 100), rats were subjected to daily treatments with a bolus of KP-54 (100 μg/kg, s.c.) or vehicle for 11 days (N = 10 per model and treatment). On Days 1, 4, 7 and 11, LH and FSH responses were assessed at different time-points within 4 h after KP-54 injection, while ovarian responses, in terms of follicular maturation and ovulation, were measured at the end of the treatment. In addition, hormonal (gonadotrophin, estrogen and inhibin B) and ovulatory responses to repeated KP-54 administration, at doses of 6.4-12.8 nmol/kg, s.c. bd for 21 days, were evaluated in a pilot cohort of anovulatory women (N = 12) diagnosed with PCOS, according to the Rotterdam criteria.

MAIN RESULTS AND THE ROLE OF CHANCE

Deregulated reproductive indices were detected in all PCOS models: PNA, NeNA and PWA. Yet, anovulation was observed only in NeNA and PWA rats. However, while anovulatory NeNA rats displayed significant LH and FSH responses to KP-54 (P < 0.05), which rescued ovulation, PWA rats showed blunted LH secretion after repeated KP-54 injection and failed to ovulate. In women with PCOS, KP-54 resulted in a small rise in LH (P < 0.05), with an equivalent elevation in serum estradiol levels (P < 0.05). Two women showed growth of a dominant follicle with subsequent ovulation, one woman displayed follicle growth but not ovulation and desensitization was observed in another patient. No follicular response was detected in the other women.

LIMITATIONS, REASONS FOR CAUTION

While three different preclinical PCOS models were used in order to capture the heterogeneity of clinical presentations of the syndrome, it must be noted that rat models recapitulate many but not all the features of this condition. Additionally, our pilot study was intended as proof of principle, and the number of participants is low, but the convergent findings in preclinical and clinical studies reinforce the validity of our conclusions.

WIDER IMPLICATIONS OF THE FINDINGS

Our first-in-rodent and -human studies demonstrate that KP-54 administration in anovulatory preclinical models and women with PCOS can stimulate reproductive hormone secretion and ovulation, albeit with incomplete efficacy. As our rat models likely reflect the diversity of PCOS phenotypes, our results argue for the need of personalized management of anovulatory dysfunction in women with PCOS, some of whom may benefit from kisspeptin-based treatments.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by research agreements between Ferring Research Institute and the Universities of Cordoba and Edinburgh. K.S. was supported by the Wellcome Trust Scottish Translational Medicine and Therapeutics Initiative (STMTI). Some of this work was undertaken in the MRC Centre for Reproductive Health which is funded by the MRC Centre grant MR/N022556/1. M.T.-S. is a member of CIBER Fisiopatología de la Obesidad y Nutrición, which is an initiative of Instituto de Salud Carlos III. Dr Mannaerts is an employee of Ferring International PharmaScience Center (Copenhagen, Denmark), and Drs Qi, van Duin and Kohout are employees of the Ferring Research Institute (San Diego, USA). Dr Anderson and Dr Tena-Sempere were recipients of a grant support from the Ferring Research Institute, and Dr Anderson has undertaken consultancy work and received speaker fees outside this study from Merck, IBSA, Roche Diagnostics, NeRRe Therapeutics and Sojournix Inc. Dr Skorupskaite was supported by the Wellcome Trust through the Scottish Translational Medicine and Therapeutics Initiative 102419/Z/13/A. The other authors have no competing interest.

Molecular phylogeny informs generic and subgeneric concepts in the Schizoptera Fieber genus group (Heteroptera : Schizopteridae) and reveals multiple origins of female-specific elytra

Wing dimorphism occurs in many genera of Schizopteridae Reuter, 1891 and other litter bugs (Heteroptera:Dipsocoromorpha), in both males and females. In the largest litter bug genus, Schizoptera Fieber, and closely related taxa, sexual wing dimorphism is observed in several species whereby males are macropterous, but females possess elytra, or hardened forewings – a feature that is rare outside of beetles and that we here refer to as female-specific elytra. Phylogenetic hypotheses for Schizoptera are unavailable, but are essential to reveal if female-specific elytra evolved once or multiple times within the genus and to test if the presence of elytra can reverse states to macropterous wings. In addition, generic and subgeneric concepts of this speciose genus-group have not been tested in a phylogenetic framework, and relationships with other schizopterid genera remain largely unknown. Our molecular phylogeny of Schizoptera and related genera documents that this genus is currently polyphyletic, and we raise the subgenus Kophaegis to generic rank to render Schizoptera monophyletic (Orthorhagus was recently elevated to genus). Relationships within Schizoptera reveal several well supported clades, some of them corresponding to currently recognised subgenera. To examine the value of previously used diagnostic features, we optimise 11 morphological characters on the molecular phylogeny and update generic and subgeneric diagnoses. Tracing transitions between macropterous and elytrous wing types, we show that female-specific elytra evolved at least seven times within Schizopteridae, four of those times within the Schizoptera genus-group, and that elytra reversed to macropterous wings at least twice. We propose that Schizopteridae may be an excellent model to study the selective pressures that have given rise to sexually dimorphic traits.

Small Bugs, Big Changes: Taxonomic Revision of Orthorhagus McAtee & Malloch

The Schizopteridae, the largest family of litter bugs (Hemiptera: Schizopteridae), comprises 53 genera of primarily tropical, tiny true bugs. The largest genus Schizoptera Fieber comprises 64 described species and six subgenera with primarily tropical and subtropical distributions across the New World. Schizoptera species are morphologically diverse with extreme asymmetry of male genitalia and sexually dimorphic wing in females of some species. Subgeneric concepts of Schizoptera are yet to be evaluated in a phylogenetic context. The subgenus Orthorhagus McAtee & Malloch was described from a single specimen as part of Schizoptera based on similarities of wing venation and other structures. The absence of a pronotal collar was used to separate Orthorhagus from other subgenera within Schizoptera, but morphological and molecular data show that the differences between Orthorhagus species and those of Schizoptera extend beyond the lack of a pronotal collar. In this study, we elevate the subgenus Orthorhagus to generic rank and describe five new species in this genus. We provide morphological documentation including digital habitus images, genitalic drawings, and confocal micrographs for all species. Distribution maps and a key to the species of Orthorhagus, n. stat. are also presented.

Effects and interactions of tachykinins and dynorphin on FSH and LH secretion in developing and adult rats

Kisspeptin/neurokinin B/dynorphin (KNDy) neurons, which coexpress kisspeptins (Kps), neurokinin B (NKB), and dynorphin (Dyn), regulate gonadotropin secretion. The KNDy model proposes that NKB (a stimulator, through NK3R) and Dyn (an inhibitor, through κ-opioid receptor) shape Kp secretion onto GnRH neurons. However, some aspects of this paradigm remain ill defined. Here we aimed to characterize the following: 1) the effects of NKB signaling on FSH secretion and 2) the role of Dyn in gonadotropin secretion after NK3R activation; 3) additionally, we explored the roles of other tachykinin receptors, NK1R and NK2R, on gonadotropin release. Thus, the effects of the NK3R agonist, senktide, on FSH release were explored across postnatal development in male and female rats; gonadotropin responses to agonists of NK1R substance P and NK2R [neurokinin A (NKA)] were also monitored. Moreover, the effects of senktide on gonadotropin secretion were assessed after antagonizing Dyn actions by nor-binaltorphimine didydrochloride. Before puberty, rats of both sexes showed increased FSH secretion to senktide (and Kp-10). Conversely, adult female rats were irresponsive to senktide in terms of FSH, despite proven LH responses, whereas the adult males did not display FSH or LH responses to senktide, even at high doses. In turn, substance P and NKA stimulated gonadotropin secretion in prepubertal rats, whereas in adults modest gonadotropin responses to NKA were detected. By pretreatment with a Dyn antagonist, adult males became responsive to senktide in terms of LH secretion and displayed elevated basal LH and FSH levels; nor-binaltorphimine didydrochloride treatment uncovered FSH responses to senktide in adult females. Furthermore, the expression of Pdyn and Opkr1 (encoding Dyn and κ-opioid receptor, respectively) in the mediobasal hypothalamus was greater in males than in females at prepubertal ages. Overall, our data contribute to refining our understanding on how the elements of the KNDy node and related factors (ie, other tachykinins) differentially participate in the control of gonadotropins at different stages of rat postnatal maturation.

Granulocyte colony-stimulating factor therapy is associated with a reduced incidence of acute rejection episodes or allograft vasculopathy in heart transplant recipients

BACKGROUND

We evaluated the potential effects of granulocyte colony-simulating factor (G- CSF) on the incidence of rejection and allograft vasculopathy in heart transplant recipients.

METHODS

Of 247 patients undergoing heart transplantation from 2000 to 2007, 52 (21%) developed leukopenia (white blood cell [WBC] <2.5 × 10(9) cells/L) in the absence of active infection, rejection, or malignancy. In 24 (46%) patients a clinical decision was made to treat the leukopenia with G-CSF (G-CSF group), and 28 (54%) Patients received no G-CSF (non-GCSF group). Patients followed up for 1 year after the period of leukopenia were assessed for allograft vasculopathy and acute rejection incidence.

RESULTS

At baseline, the G-CSF group and the non-GCSF group did not differ in age, gender, race, heart failure etiology, creatinine, left ventricular ejection fraction (LVEF) or immunosupressive regimen. During 1-year follow-up there were no deaths in the G-CSF group, and 1 death in the non-GCSF group (P = .34). The incidence of rejection or progressive allograft vasculopathy was lower in the G-CSF group when compared with the non-GCSF group (2 [8%] vs 15 [53%]; P < .01). Multivariate analysis identified both prior rejection episodes and G-CSF therapy as factors associated with the combined end-point of rejection or progressive allograft vasculopathy (odds ratio [OR] = 7.89 [1.67-37.2] and OR = 0.09 [0.02-0.52], respectively).

CONCLUSIONS

G-CSF therapy appears to be associated with a decreased incidence of acute rejection episodes or allograft vasculopathy in heart transplant recipients, suggesting a potential immunomodulatory effect of G-CSF.

Metabolic programming of puberty: sexually dimorphic responses to early nutritional challenges

Body energy stores and metabolic cues influence the onset of puberty. However, the pubertal impact of early nutritional challenges has been only fragmentarily addressed. We evaluated here the consequences, in terms of pubertal timing and hormonal markers, of various nutritional manipulations during pre- or postnatal maturation in rats of both sexes. Males and females were submitted to gestational undernutrition (UNG) or peripubertal (SUB) subnutrition or were raised in large (LL; underfeeding) or small (SL; overfeeding) litters. In addition, groups of UNG, LL, and SL rats were fed on a high-fat diet (HFD) after weaning. Postnatal overfeeding resulted in higher body weights (BWs) during pubertal transition in both sexes, but only SL males displayed overtly advanced external signs of puberty. Postnatal underfeeding persistently decreased BW gain during puberty, yet the magnitude of pubertal delay was greater in LL males. In contrast, regardless of postnatal nutrition, HFD tended to advance the onset of puberty in females but did not alter pubertal timing in males. Likewise, SUB females displayed a marked delay in BW gain and puberty onset, whereas despite similar reduction in BW, SUB males showed normal timing of puberty. These sex divergences were also detected in various hormonal and metabolic indices so that postnatal overnutrition consistently increased LH, FSH, leptin, and insulin levels only in pubertal females, whereas HFD decreased gonadotropin levels in SL females but increased them in SL males. Notably, UNG rats did not show signs of delayed puberty but displayed a striking sex dimorphism in serum insulin/glucose levels, regardless of the diet, so that only UNG males had signs of presumable insulin resistance. Our data disclose important sex differences in the impact of various early nutritional challenges on the timing of puberty, which may help to explain the different trends of altered puberty and related comorbidities between sexes.

Changes in hypothalamic expression of the Lin28/let-7 system and related microRNAs during postnatal maturation and after experimental manipulations of puberty

Lin28 and Lin28b are related RNA-binding proteins that inhibit the maturation of miRNAs of the let-7 family and participate in the control of cellular stemness and early embryonic development. Considerable interest has arisen recently concerning other physiological roles of the Lin28/let-7 axis, including its potential involvement in the control of puberty, as suggested by genome-wide association studies and functional genomics. We report herein the expression profiles of Lin28 and let-7 members in the rat hypothalamus during postnatal maturation and in selected models of altered puberty. The expression patterns of c-Myc (upstream positive regulator of Lin28), mir-145 (negative regulator of c-Myc), and mir-132 and mir-9 (putative miRNA repressors of Lin28, predicted by bioinformatic algorithms) were also explored. In male and female rats, Lin28, Lin28b, and c-Myc mRNAs displayed very high hypothalamic expression during the neonatal period, markedly decreased during the infantile-to-juvenile transition and reached minimal levels before/around puberty. A similar puberty-related decline was observed for Lin28b in monkey hypothalamus but not in the rat cortex, suggesting species conservation and tissue specificity. Conversely, let-7a, let-7b, mir-132, and mir-145, but not mir-9, showed opposite expression profiles. Perturbation of brain sex differentiation and puberty, by neonatal treatment with estrogen or androgen, altered the expression ratios of Lin28/let-7 at the time of puberty. Changes in the c-Myc/Lin28b/let-7 pathway were also detected in models of delayed puberty linked to early photoperiod manipulation and, to a lesser extent, postnatal underfeeding or chronic subnutrition. Altogether, our data are the first to document dramatic changes in the expression of the Lin28/let-7 axis in the rat hypothalamus during the postnatal maturation and after different manipulations that disturb puberty, thus suggesting the potential involvement of developmental changes in hypothalamic Lin28/let-7 expression in the mechanisms permitting/leading to puberty onset.

159 COMPARISON BETWEEN EQUINE CHORIONIC GONADOTROPIN AND PORCINE FOLLICLE STIMULATING HORMONE FOR IN VIVO PRODUCTION OF EMBRYOS IN ALPACAS (VICUGNA PACOS) SHOWING NATURAL LUTEAL PHASE AFTER INDUCTION OF OVULATION

Alpacas are animals with induced ovulation, andthey show high individual variation in the symptoms, duration, and regularity of oestrus or period of female receptivity to males; their follicular phase does not end in ovulation and subsequent luteal phase unless an external stimulation such as copulation or exogenous application of an ovulation inducing hormone is applied. The objective of the present study was to compare the use of eCG v. porcine (p)FSH as superovulatory hormones for the in vivo production of embryos in alpacas that were selected as being receptive to the male and were treated with an ovulation-inducing hormone to generate a luteal phase. Twenty adult (3 to 5 years old) female alpacas, located at Mallkini, Puno, Peru (at 4100 m elevation), were used for the trial. A group of females was exposed to males to test for breeding receptivity; 20 alpacas were receptive, adopting copulatory position. Each of the selected females received 3.75 mg of LH IM (Lutropin®, Bioniche Animal Health, Belleville, ON, Canada). Day 0 was then considered the date of LH injection. The 20 alpacas were then distributed into 2 treatments: Treatment 1 (T1 = 10 alpacas) received on Day 2, 1000 IU of eCG IM (Pregnecol®, Bioniche Animal Health) and on Day 7, a dose of PGF2α IM (0.263 mg of cloprostenol; Ciclar®, Andeanvet-Zoovet, Lima, Peru). Treatment 2 alpacas (T2 = 10 alpacas) received from Day 2 and up to Day 5, at 12-h interval, decreasing doses of pFSH IM (100 mg; Folltropin V®, Bioniche Animal Health) for 4 days, and on Day 7, a dose of PGF2α IM (0.263 mg of cloprostenol; Ciclar®, Andeanvet-Zoovet). All alpacas from T1 and T2 were mated twice with fertile males, the first mating at 24 h after the injection of PGF2α and the second at 12 h after the first mating. All females received a dose of GnRH IM (0.0084 mg of buserelin; Buserelina®, Andeanvet-Zoovet) at time of first mating. The embryos in both treatments were collected 6.5 days after the first mating by nonsurgical transcervical embryo flushing. There were no significant differences in the mean number of blastocysts collected per treatment (P > 0.05), being 3.0 ± 2.87 blastocyst for T1 and 1.6 ± 2.67 for T2. The number of blastocysts per treatment was 30 and 16 for T1 and T2, respectively. The results show that superovulatory treatment with eCG is more effective for the production of viable blastocysts than treatment with pFSH in alpacas treated for superovulation during the luteal phase. This work was partially funded by Bioniche Animal Health.

200 EVALUATION OF SUPEROVULATORY REGIMES FOR IN VIVO EMBRYO PRODUCTION IN ALPACAS (LAMA PACOS)

The objective of the study was to evaluate 4 superovulatory regimes in terms of the quantity of transferable embryos recovered. A total of 48 female alpacas, 3 to 5 years of age and located at Malkini Alpacas Farm (4100 m elevation), were distributed into 4 treatments. In treatment 1, 13 female alpacas received on Day 0 an intravaginal device containing 0.78 mg of progesterone (Cue Mate®, Bioniche Animal Health, Belleville, Ontario, Canada) followed immediately by an i.m injection of estradiol (1 mg of estradiol benzoate) and an i.m. injection of PGF2α (Veyx®, 0.25 mg of cloprostenol). The intravaginal device was removed on Day 7, performing at removal time an i.m. injection of estradiol. From Days 8 to 16, the alpacas received an i.m injection twice per day and 12 hours apart of pFSH (FolltropinV®, Bioniche Animal Health) in decreasing doses totaling 420 mg of pFSH; on Day 16,300 IU of eCGi.m. (Pregnecol®, Bioniche Animal Health) was injected. In treatment 2, 13 alpacas received on Day 0 an intravaginal device of progesterone followed by an i.m. injection of PGF2; from Days 5 to 9, alpacas received injections twice per day of decreasing doses of pFSH (porcine FHS) totaling 320 mg; on Day 7, the intravaginal device was removed and 500 IU i.m. of eCG was injected. In treatment 3,13 alpacas received on Day 0 an intravaginal device of progesterone followed immediately by an i.m injection of GnRH (Conceptal®, 0.0042 mg of acetate of busereline); pFSH was injected i.m. from Days 5 to 9 in decreasing doses twice per day, totaling 440 mg; the intravaginal device was removed on Day 7. In treatment 4, 9 female alpacas received on Day 0 an i.m. injection of GnRH after verifying the presence of a preovulatory follicle (>8.0 mm diameter). On Day 2, the alpacas received 1000 IU i.m. of eCG followed on Day 7 by an i.m. injection of PGF2. In all cases, the donor alpacas were evaluated by ultrasonography. The matings for treatments 1, 2, and 3 were performed twice per donor alpaca at 12-hour intervals between Days 5 and 8 of the initiation of the pFSH treatments, whereas in treatment 4 the matings were made the following day after the application of the PGF2. In treatment 1, the donor alpacas received at time of first mating an i.m injection of 3.75 mg of LH (Lutropin®, Bioniche Animal Health); in treatments 2, 3, and 4, the donors received an i.m. injection of GnRH. In all treatments, embryo collection was performed by nonsurgical method 6.5 days after first mating. There were significant differences between treatments (P < 0.05) in the mean number of CL, with treatment 4 being the highest (4.7 ± 2.63, 4.1 ± 3.05, 1.8 ± 1.8, and 6.0 ± 3.16 for treatments 1 to 4, respectively). The total number of blastocysts recovered per treatment was 7, 16, 2, and 18 for treatments 1 to 4, respectively. The superovulatory strategy followed for treatment 4 showed to be the one resulting in the highest number of transferable embryos. Further comparative evaluations between FSH and eCG treatments are recommended. Research was partially funded by the contributions of Bioniche Animal Health.

Prevalence of bacterial vaginosis among young women in low-income populations of coastal Peru

The goal of this study was to determine the prevalence of bacterial vaginosis (BV) in Peruvian women from socioeconomically deprived populations and to determine the association between BV and risk factors for sexually transmitted diseases (STDs). Women were administered an epidemiologic survey to determine sexual risk behaviour and they provided biological samples to test for BV and STDs. The prevalence of BV was high (27%) and was significantly associated with having a bacterial STD or trichomoniasis. Age, marital status, and a history of sex work, but not of sexual experience, frequency of intercourse, and unprotected intercourse, were associated with BV. As BV may be a marker for STDs, screening for STDs should be performed in individuals with BV to promote early detection and treatment of co-infecting sexually transmitted pathogens.

Estimating the cost of developmental and behavioral screening of preschool children in general pediatric practice

OBJECTIVE

Despite increased recognition of the importance of development and growth of young children, formal developmental and behavioral screening often is not included in general pediatric practice. Barriers to the provision of developmental and behavioral screening are considerable; among them are the need for specialized training and uncertain reimbursement. This article develops a model for estimating the cost of providing pediatric developmental and behavioral screening that can be scaled to reflect a pediatric practice's patient population and choice of screening offered.

METHODS

The framework for our scaleable cost model was drawn from work done in estimating the Resource-Based Relative Value Scale (RBRVS). RBRVS provides estimates of the work effort involved in the provision of health care services for individual Current Procedural Terminology codes. The American Academy of Pediatrics has assigned descriptions of pediatric services, including developmental and behavioral screening, to the Current Procedural Terminology codes originally created for adult health care services. The cost of conducting a screen was calculated as a function of the time and staff required and was loaded for practice costs using the RBRVS valuation. The cost of the follow-up consultation was calculated as a function of the time and staff required and the number of relative value units assigned in the RBRVS scale.

RESULTS

The practice cost of providing developmental and behavioral screening is driven primarily by the time and staff required to conduct and evaluate the screens. Administration costs are lowest for parent-administered developmental screens ($0 if no assistance is required) and highest ($67) for lengthy, pediatric provider-administered screens, such as the Neonatal Behavioral Assessment Scale. The costs of 3 different groups of developmental and behavioral screening are estimated. The estimated per-member per-month cost per 0- to 3-year-old child ranges from $4 to >$7 in our 3 examples.

CONCLUSIONS

Cost remains a significant barrier to greater provision of formal developmental and behavioral screening. Our scaleable cost model may be adjusted for a given practice to account for the overall level of developmental risk. The model also provides an estimate of the time and cost of providing new screening services. This model allows pediatric practices to select the mix of developmental screens most appropriate for their particular patient population at an acceptable cost.

Pituitary tumorigenesis and hPit-1 cells

Despite decades of clinical data verifying the success of therapeutic approaches to human pituitary tumors, a significant number of tumors progress and can be life-threatening. The development of better therapeutic strategies for pituitary tumors is complicated by the relative scarcity of human pituitary material for basic experimentation. Human pituitary tissue was used to derive cell cultures, and a cell line, hPIT-1. Molecular and functional analyses were used to further characterize the cells as human pituitary explants in vitro. Functional analyses of the cell cultures indicated that the cells were tumorigenic and of human folliculostellate origin. hPit-1 cells revealed numerous abnormalities of ploidy. Molecular analyses indicated the absence of expression of the following pituitary hormones or hormone subunits by this culture: growth hormone, prolactin, ACTH, FSHbeta, LHbeta, THbeta, and p-glycoprotein. By contrast, the cells expressed uniformly high levels of human follistatin mRNA. Finally, the cells are moderately tumorigenic in immune-deficient mice. Although the precise molecular genetic mechanisms for tumorigenesis in the established cell culture are unknown, the cells serve as a future resource in the study of pituitary tumor initiation, progression, and response to therapy.

Effect of chronic ethanol consumption on protective T-helper 1 and T-helper 2 immune responses against the parasites Leishmania major and Strongyloides stercoralis in mice

BACKGROUND

Chronic alcohol consumption has been associated with significant increases in the prevalence of infectious diseases, and it has been suggested that these increases are caused by a direct effect of ethanol on the immune response. The objective of this study was to determine whether chronic ethanol consumption would affect the development of protective immunity to Leishmania major, which is controlled by the T-helper 1 (Th1) subset of CD4 cells, and Strongyloides stercoralis, which is controlled by the Th2 subset.

METHODS

Mice were fed ethanol-containing liquid diet (25% ethanol-derived calories), liquid isocaloric diet without ethanol, or solid chow and then exposed to either of the two parasites. The ability of the mice chronically consuming alcohol to eliminate the infections was determined, as were the levels of parasite-specific humoral and cellular immune responses.

RESULTS

Mice chronically consuming alcohol were capable of eliminating both of these infections in a manner identical to the control mice. In addition, splenocytes from mice chronically consuming alcohol infected with L. major produced nitric oxide at the same levels as in control mice. Antibody responses were altered in a manner suggesting an increase in Th2 immunity and a decrease in Th1 immunity in the mice chronically consuming alcohol. In mice chronically consuming alcohol that were infected with S. stercoralis, eosinophils migrated to the parasite's microenvironment, and antibodies were produced at levels equivalent to those seen in control mice.

CONCLUSIONS

Mice maintained on an ethanol-containing liquid diet had some alteration in their ability to produce Th1 and Th2 immune responses yet were capable of generating unimpaired protective Th1 and Th2 responses.

Development of a recombinant antigen vaccine against infection with the filarial worm Onchocerca volvulus

Efforts to control Onchocerca volvulus, the etiologic agent of river blindness, have been limited to vector control and drug treatment to eliminate microfilariae, with no means available to prevent infection. The goal of this study was to develop a vaccine against this infection using recombinant antigens that are expressed in the early larval stages of the parasite. Five recombinant antigens, Ov7, Ov64, OvB8, Ov9M, and Ov73k, were identified by screening adult and larval cDNA libraries with antibodies from immune humans, chimpanzees, or rabbits. When mice were immunized with the five individual recombinant antigens, statistically significant reductions in parasite survival were induced in mice immunized with Ov7, OvB8, or Ov64, when administered in alum but not when injected in Freund's complete adjuvant (FCA). Live larvae recovered from control and immunized mice were analyzed to determine their developmental stages. A decrease in the percentage of larvae molting from the third stage to the fourth stage was observed with mice immunized with Ov7, Ov64, or OvB8 in alum but not with mice immunized with Ov9 and Ov73k or with mice immunized with any of the five antigens in FCA. Mice immunized with a cocktail of the three protective antigens developed protective immunity equal to that seen with mice immunized with individual antigens. This study has identified, for the first time, three recombinant antigens capable of inducing protective immunity to O. volvulus. Furthermore, since the antigens functioned with alum as the adjuvant, this vaccine could potentially be used clinically to prevent river blindness in humans.

Characteristics of physicians presenting for assessment at a behavioral health center

Physician health and impairment have been of considerable interest in recent years. This study contributes detailed clinical data to the existing body of knowledge, by drawing from a sample of physicians assessed at a behavioral health center over a two year time frame. Demographic, referral, and clinical data were gathered using a systematic medical record review procedure, based on 108 physicians who were evaluated within an intensive multidisciplinary assessment program. The majority suffered from active substance use disorders (52.8%), with other psychiatric disorders (29.6%), and substance use disorders in remission (17.6%) the other largest categories. Of those with an active substance use disorder, primary drugs of choice were alcohol and prescription opiates. Over half had comorbid psychiatric disorders (Axis I, II, or both). Significant relationship, employment, and emotional problems were found in all three groups. The significant increase in presentation and/or detection of psychiatric and behavioral problems, both comorbid with and not substance use related, confirms the need for a revision and expansion of views about physicians' behavioral health concerns.

Lens injury stimulates axon regeneration in the mature rat optic nerve

In mature mammals, retinal ganglion cells (RGCs) are unable to regenerate their axons after optic nerve injury, and they soon undergo apoptotic cell death. However, a small puncture wound to the lens enhances RGC survival and enables these cells to regenerate their axons into the normally inhibitory environment of the optic nerve. Even when the optic nerve is intact, lens injury stimulates macrophage infiltration into the eye, Müller cell activation, and increased GAP-43 expression in ganglion cells across the entire retina. In contrast, axotomy, either alone or combined with intraocular injections that do not infringe on the lens, causes only a minimal change in GAP-43 expression in RGCs and a minimal activation of the other cell types. Combining nerve injury with lens puncture leads to an eightfold increase in RGC survival and a 100-fold increase in the number of axons regenerating beyond the crush site. Macrophage activation appears to play a key role, because intraocular injections of Zymosan, a yeast cell wall preparation, stimulated monocytes in the absence of lens injury and induced RGCs to regenerate their axons into the distal optic nerve.

Formation of molecular gas in the tidal debris of violent galaxy-galaxy interactions

In many gravitational interactions between galaxies, gas and stars that have been torn from the precursor galaxies can collect in tidal 'tails'. Star formation begins anew in some of these regions, producing tidal dwarf galaxies. Observations of these new galaxies provides insight into processes relevant to galaxy formation more generally, because the timescale of the interaction is well defined. But tracking the star formation process has hitherto been difficult because the tidal dwarf galaxies with young stars showed no evidence of the molecular gas out of which those young stars formed. Here we report the discovery of molecular hydrogen (traced by carbon monoxide emission) in two tidal dwarf galaxies. In both cases, the concentration of molecular gas peaks at the same location as the maximum in atomic-hydrogen density, unlike the situation in most gas-rich galaxies. We infer from this that the molecular gas formed from the atomic hydrogen, rather than being torn in molecular form from the interacting galaxies. Star formation in the tidal dwarf galaxies therefore appears to mimic the process in normal spiral galaxies like our own.

Evaluation of resins for on-bead screening: a study of papain and chymotrypsin specificity using PEGA-bound combinatorial peptide libraries

TentaGel, ArgoGel and PEGA resins were evaluated for on-bead biological screening, using a fluorescently-labelled peptide attached to each and assayed for papain activity. Peptide attached to PEGA was cleaved in near quantitative yield at the expected sites, whilst an identical sequence on TentaGel and ArgoGel beads was hydrolysed in very low yields and nonspecifically on ArgoGel. The compatibility of PEGA with enzymes was further demonstrated by the determination of subsite specificities of papain and chymotrypsin using PEGA-bound peptide libraries, which proved to be similar to those observed in free solution.

Female physicians and substance abuse. Comparisons with male physicians presenting for assessment

As with women in general, the vicissitudes of the female physician who suffers from a substance use disorder have been understudied, and such persons remain underrepresented in treatment. The purpose of the present study is to describe the similarities and differences between female and male physicians presenting for assessment; 108 physicians in total were included in the study, 10 of whom were female. Demographically, we found that the female physicians were more likely to be single and younger than their male counterparts. On clinical indices, females showed less impairment on legal and medical functioning, and better capability in sustaining abstinence and eliminating environmental cues to relapse. Of the women with substance use disorders, higher rates of comorbidity were found than with males. Although there were no significant differences in overall severity, males were more likely to be recommended to more intensive levels of care for either substance use or psychiatric disorders. The female physicians were recommended to a level of care of a lower intensity, but more often to a treatment with a dual-diagnosis focus. These findings are discussed in terms of the vulnerabilities of the female physician, barriers to treatment, tailoring treatment to female needs, and opportunities for prevention and further research.

Differential therapeutics and the impaired physician: patient-treatment matching by specificity and intensity

The objective of this study was to determine the nature and degree of patient to treatment matching for a sample of physicians based on differential problem type and severity. Methods included a single assessment of variables using retrospective chart review. Subjects included 108 physicians (98 men and 10 women), who were sampled consecutively from assessments performed over a 2-year period. They represented a variety of specialties, and most were third-party referred, predominantly by state medical societies. Main outcome measures included demographic information, DSM-IV multiaxial diagnoses, the Severity of Substance-Related Disorder scale, and the type and intensity of recommended treatment. It was found that the physicians presented with a variety of conditions that were clustered into three categories: active substance use disorders (52.8%), substance use disorders in remission (17.6%), and psychiatric/behavioral problems (29.6%). An analysis of the appropriateness of matching types of treatment to these problem categories appeared to support a differential assignment process. A range in severity was also found within problem categories and was subsequently tested for correspondence with the range in intensity of recommended treatment. It was found that severity correlated strongly with recommended treatment intensity for all groups. In addition, multiple regression analyses showed that two factors, ability to sustain abstinence and emotional disturbance, were predictive of treatment intensity for the two substance use disorder subgroups (64% of variance accounted for). In the psychiatric/behavioral problem subgroup, such analysis demonstrated that the severity of difficulties with one's significant other was predictive of treatment intensity (89% of variance accounted for).

Measuring inhibitory control in children

The Stop Signal Task is a measure of inhibitory control in which subjects must press a button in response to a stimulus. On certain trials, the subject receives a second stimulus (the Stop Signal) after the primary stimulus and must withhold his/her response during those trials. The onset of the Stop Signal is varied, sometimes coming immediately after the primary stimulus (inhibition is easy); at other times, the Stop Signal arrives quite late, making inhibition difficult. Results from the Stop Signal Task were obtained from children with attention-deficit/hyperactivity disorder (ADHD) and from controls; children with ADHD had significantly more difficulty inhibiting their responses than did controls. In a second study, results from the Stop Signal Task were obtained from a large sample of both behaviorally disturbed and community children; variables from the Stop Signal Task correlated well with both laboratory observations and teacher ratings of inattention and hyperactivity.

Clinical dementia rating training and reliability in multicenter studies: the Alzheimer's Disease Cooperative Study experience

Global ratings of dementia severity are used increasingly in clinical trials of antidementia compounds. Such ratings are clinically relevant, but their reliability in multicenter settings has not been determined. To evaluate the reliability of one global scale, the Clinical Dementia Rating (CDR), 82 investigators of the multicenter Alzheimer's Disease Cooperative Study participated in a training and reliability protocol using videotaped assessments of subjects in various stages of Alzheimer's disease. Following training, overall agreement of the investigators with "gold standard" CDR scores was 83%. These results indicate that the training protocol is useful for establishing good levels of agreement in staging dementia severity and that the CDR can be standardized as a clinical global scale for multicenter studies of Alzheimer's disease.