Phase II multicentre trial of oral quisinostat, a histone deacetylase inhibitor, in patients with previously treated stage IB-IVA mycosis fungoides/Sézary syndrome.

BACKGROUND: Quisinostat is a hydroxamate, second-generation, orally available pan-histone deacetylase inhibitor. OBJECTIVES: To evaluate the efficacy and safety of oral quisinostat in patients with previously treated cutaneous T-cell lymphoma (CTCL). METHODS: Patients received quisinostat 8 mg or 12 mg on days 1, 3 and 5 of each week in 21-day treatment cycles. Primary efficacy end point was cutaneous response rate (RR) based on the modified Severity Weighted Assessment Tool (mSWAT). Secondary end points included global RR, duration of response (DOR) in skin, progression-free survival (PFS), pruritus relief, safety and pharmacodynamic markers. RESULTS: Eight of 26 (25 evaluable) patients achieved ≥ 50% reduction in mSWAT score at least once, with confirmed cutaneous response in six (RR 24%). There was a low global RR of 8%. DOR in skin ranged from 2·8 to 6·9 months. Median PFS was 5·1 months. Pruritus relief was more frequent in cutaneous responders (67%) than nonresponders (32%). Serial tumour biopsies revealed an increase in acetylated tubulin, indicating a target effect of histone deacetylase 6. Twenty-one of 26 (81%) patients were withdrawn from the study before or at clinical cut-off; five (19%) continued to receive treatment with quisinostat. The most common drug-related adverse events were nausea, diarrhoea, asthenia, hypertension, thrombocytopenia and vomiting. Grade 3 drug-related adverse events included hypertension, lethargy, pruritus, chills, hyperkalaemia and pyrexia. CONCLUSIONS: Quisinostat 12 mg three times weekly is active in the treatment of patients with relapsed or refractory CTCL, with an acceptable safety profile. Combination therapy with other drugs active in CTCL may be appropriate.

Platelet sequestration and activation during GalTKO.hCD46 pig lung perfusion by human blood is primarily mediated by GPIb, GPIIb/IIIa, and von Willebrand Factor.

BACKGROUND: Here, we ask whether platelet GPIb and GPIIb/IIIa receptors modulate platelet sequestration and activation during GalTKO.hCD46 pig lung xenograft perfusion. METHODS: GalTKO.hCD46 transgenic pig lungs were perfused with heparinized fresh human blood. Results from perfusions in which αGPIb Fab (6B4, 10 mg/l blood, n = 6), αGPIIb/IIIa Fab (ReoPro, 3.5 mg/l blood, n = 6), or both drugs (n = 4) were administered to the perfusate were compared to two additional groups in which the donor pig received 1-desamino-8-d-arginine vasopressin (DDAVP), 3 µg/kg (to pre-deplete von Willebrand Factor (pVWF), the main GPIb ligand), with or without αGPIb (n = 6 each). RESULTS: Platelet sequestration was significantly delayed in αGPIb, αGPIb+DDAVP, and αGPIb+αGPIIb/IIIa groups. Median lung "survival" was significantly longer (>240 vs. 162 min reference, p = 0.016), and platelet activation (as CD62P and ßTG) were significantly inhibited, when pigs were pre-treated with DDAVP, with or without αGPIb Fab treatment. Pulmonary vascular resistance rise was not significantly attenuated in any group, and was associated with residual thromboxane and histamine elaboration. CONCLUSIONS: The GPIb-VWF and GPIIb/IIIa axes play important roles in platelet sequestration and coagulation cascade activation during GalTKO.hCD46 lung xenograft injury. GPIb blockade significantly reduces platelet activation and delays platelet sequestration in this xenolung rejection model, an effect amplified by adding αGPIIb/IIIa blockade or depletion of VWF from pig lung.

Pig-to-monkey islet xenotransplantation using multi-transgenic pigs.

The generation of pigs with genetic modifications has significantly advanced the field of xenotransplantation. New genetically engineered pigs were produced on an α1,3-galactosyltransferase gene-knockout background with ubiquitous expression of human CD46, with islet beta cell-specific expression of human tissue factor pathway inhibitor and/or human CD39 and/or porcine CTLA4-lg. Isolated islets from pigs with 3, 4 or 5 genetic modifications were transplanted intraportally into streptozotocin-diabetic, immunosuppressed cynomolgus monkeys (n = 5). Immunosuppression was based on anti-CD154 mAb costimulation blockade. Monitoring included features of early islet destruction, glycemia, exogenous insulin requirement and histopathology of the islets at necropsy. Using these modified pig islets, there was evidence of reduced islet destruction in the first hours after transplantation, compared with two series of historical controls that received identical therapy but were transplanted with islets from pigs with either no or only one genetic modification. Despite encouraging effects on early islet loss, these multi-transgenic islet grafts did not demonstrate consistency in regard to long-term success, with only two of five demonstrating function beyond 5 months.

Expression of human CD46 modulates inflammation associated with GalTKO lung xenograft injury.

Evaluation of lungs from GalTKO.hCD46 pigs, genetically modified to lack the galactose-α(1,3)-galactose epitope (GalTKO) and to express human CD46, a complement regulatory protein, has not previously been described. Physiologic, hematologic and biochemical parameters during perfusion with heparinized fresh human blood were measured for 33 GalTKO.hCD46, GalTKO (n = 16), and WT pig lungs (n = 16), and 12 pig lungs perfused with autologous pig blood. Median GalTKO.hCD46 lung survival was 171 min compared to 120 for GalTKO (p = 0.27) and 10 for WT lungs (p < 0.001). Complement activation, platelet activation and histamine elaboration were significantly reduced during the first 2 h of perfusion in GalTKO.hCD46 lungs compared to GalTKO (ΔC3a at 120' 812 ± 230 vs. 1412 ± 1047, p = 0.02; ΔCD62P at 120' 9.8 ± 7.2 vs. 25.4 ± 18.2, p < 0.01; Δhistamine at 60' 97 ± 62 vs. 189 ± 194, p = 0.03). We conclude that, in addition to significant down-modulation of complement activation, hCD46 expression in GalTKO lungs diminished platelet and coagulation cascade activation, neutrophil sequestration and histamine release. Because GalTKO.hCD46 lung failure kinetics correlated directly with platelet and neutrophil sequestration, coagulation cascade activation and a rise in histamine levels within the first hour of perfusion, further progress will likely depend upon improved control of these pathways, by rationally targeted additional modifications to pigs and pharmacologic interventions.

Concerns and coping during cancer genetic risk assessment.

OBJECTIVE: To gain an 'in-depth' understanding of patients' concerns and their related coping strategies during the genetic risk assessment process. METHODS: Participants were the 'usual care' arm of a trial of a coping intervention targeted at men and women undergoing assessment of genetic risk for familial cancer. Participants completed questionnaires measuring the degree to which they experienced up to 11 concerns and which of 8 coping strategies they used to respond to each of them at entry into the programme and 1 month subsequently (before they received their risk information). FINDINGS: A majority of participants were at least 'quite worried' about all the identified concerns, although the levels of concern fell over the waiting period. Participants used several strategies in response to their varying concerns - although a primary coping strategy for each concern was identifiable. The emotion-focused strategies of acceptance and positive appraisal were generally used in response to concerns they could not change, and seeking social support was used primarily to gain information, but not emotional support from their family. Cluster analysis identified three unique clusters of coping responses. CONCLUSIONS: Genetic risk assessment comprises a number of different stressors each of which is coped with using different strategies.

Stigma, social appearance anxiety and coping in men and women living with skin conditions: A mixed methods analysis.

Background: The psychological impact of living with a skin condition can have a profound impact on quality of life and could cause appearance-related social anxiety. Existing research suggests ambiguous findings in relation to whether the impact of living with a skin condition differs between males and females. Objectives: The present study aimed to explore the association between stigma, coping styles and social appearance anxiety in men and women living with a skin condition in the United Kingdom. Methods: 231 participants (n = 199 females, n = 30 males, n = 2 non-binary) completed a cross-sectional online questionnaire, capturing quantitative data with the social appearance anxiety scale (SAAS), the shortened version of the coping inventory for stressful situations (CISS-21), and qualitative data from free-text comments and thematic content analysis. Respondents were also asked to provide additional free text comments in relation to the challenges faced and how these were managed. Results: Content analysis revealed that males and females faced daily practical, social and emotional challenges and coped with them in several ways; with higher levels of social appearance anxiety associated with both higher perceived severity of skin condition and younger age. Males and females appeared equally as emotionally affected by living with a skin condition, with the only significant gender difference being females as significantly more likely to engage in avoidant coping behaviours than males. Conclusions: Living with a skin condition presents daily practical, social, and psychological challenges for males and females that have the potential to impact on quality of life. Findings highlight the need for dermatological care to routinely address these issues, and psychosocial interventions must be made available to promote healthy coping with skin conditions.

Targeted disruption of the porcine immunoglobulin kappa light chain locus.

Inactivation of the endogenous pig immunoglobulin (Ig) loci, and replacement with their human counterparts, would produce animals that could alleviate both the supply and specificity issues of therapeutic human polyclonal antibodies (PAbs). Platform genetics are being developed in pigs that have all endogenous Ig loci inactivated and replaced by human counterparts, in order to address this unmet clinical need. This report describes the deletion of the porcine kappa (κ) light chain constant (Cκ) region in pig primary fetal fibroblasts (PPFFs) using gene targeting technology, and the generation of live animals from these cells via somatic cell nuclear transfer (SCNT) cloning. There are only two other targeted loci previously published in swine, and this is the first report of a targeted disruption of an Ig light chain locus in a livestock species. Pigs with one targeted Cκ allele (heterozygous knockout or ±) were bred together to generate Cκ homozygous knockout (-/-) animals. Peripheral blood mononuclear cells (PBMCs) and mesenteric lymph nodes (MLNs) from Cκ -/- pigs were devoid of κ-containing Igs. Furthermore, there was an increase in lambda (λ) light chain expression when compared to that of wild-type littermates (Cκ +/+). Targeted inactivation of the Ig heavy chain locus has also been achieved and work is underway to inactivate the pig lambda light chain locus.

Generation of antibody- and B cell-deficient pigs by targeted disruption of the J-region gene segment of the heavy chain locus.

A poly(A)-trap gene targeting strategy was used to disrupt the single functional heavy chain (HC) joining region (J(H)) of swine in primary fibroblasts. Genetically modified piglets were then generated via somatic cell nuclear transfer (SCNT) and bred to yield litters comprising J(H) wild-type littermate (+/+), J(H) heterozygous knockout (±) and J(H) homozygous knockout (-/-) piglets in the expected Mendelian ratio of 1:2:1. There are only two other targeted loci previously published in swine, and this is the first successful poly(A)-trap strategy ever published in a livestock species. In either blood or secondary lymphoid tissues, flow cytometry, RT-PCR and ELISA detected no circulating IgM(+) B cells, and no transcription or secretion of immunoglobulin (Ig) isotypes, respectively in J(H) -/- pigs. Histochemical and immunohistochemical (IHC) studies failed to detect lymph node (LN) follicles or CD79α(+) B cells, respectively in J(H) -/- pigs. T cell receptor (TCR)(ß) transcription and T cells were detected in J(H) -/- pigs. When reared conventionally, J(H) -/- pigs succumbed to bacterial infections after weaning. These antibody (Ab)- and B cell-deficient pigs have significant value as models for both veterinary and human research to discriminate cellular and humoral protective immunity to infectious agents. Thus, these pigs may aid in vaccine development for infectious agents such as the pandemic porcine reproductive and respiratory syndrome virus (PRRSV) and H1N1 swine flu. These pigs are also a first significant step towards generating a pig that expresses fully human, antigen-specific polyclonal Ab to target numerous incurable infectious diseases with high unmet clinical need.

The development of a cancer genetic-specific measure of coping: the GRACE.

OBJECTIVE: Generic measures of coping fail to capture the process of undergoing specific health processes such as cancer genetic risk assessment. The Genetic Risk Assessment Coping Evaluation (GRACE) has been developed to provide greater specificity of measurement. METHOD: Based upon previous research findings, the GRACE measures the degree of stress associated with 11 recognised sources of stress for individuals undergoing the early stages of cancer genetic risk assessment, and the use of up to eight coping strategies they may elicit. This paper reports preliminary data from the piloting of the GRACE within a randomised trial of a coping intervention. RESULTS: Of the 265 participants who completed and returned their baseline questionnaire (prior to being informed of their level of genetic risk), 257 completed the GRACE. The most highly endorsed sources of stress involved concerns relating to family members, endorsed by over 60% of respondents, and concerns about how the participants would cope if found to be at increased risk (59%). Participants made use of multiple coping strategies across different sources of stress. The most frequently reported coping strategies were emotion-focused, which may reflect the stage of the assessment process. CONCLUSION: The completion rates for the matrix and specificity of responses provided suggest that the GRACE may be an acceptable measurement tool. Further data collection and validation is ongoing.

Updated results from the phase 3 HELIOS study of ibrutinib, bendamustine, and rituximab in relapsed chronic lymphocytic leukemia/small lymphocytic lymphoma.

We report follow-up results from the randomized, placebo-controlled, phase 3 HELIOS trial of ibrutinib+bendamustine and rituximab (BR) for previously treated chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) without deletion 17p. Overall, 578 patients were randomized 1:1 to either ibrutinib (420 mg daily) or placebo, in combination with 6 cycles of BR, followed by ibrutinib or placebo alone. Median follow-up was 34.8 months (range: 0.1-45.8). Investigator-assessed median progression-free survival (PFS) was not reached for ibrutinib+BR, versus 14.3 months for placebo+BR (hazard ratio [HR] [95% CI], 0.206 [0.159-0.265]; P < 0.0001); 36-month PFS rates were 68.0% versus 13.9%, respectively. The results are consistent with the primary analysis findings (HR = 0.203, as assessed by independent review committee, with 17-month median follow-up). Median overall survival was not reached in either arm; HR (95% CI) for ibrutinib+BR versus placebo: 0.652 (0.454-0.935; P = 0.019). Minimal residual disease (MRD)-negative response rates were 26.3% for ibrutinib+BR and 6.2% for placebo+BR (P < 0.0001). Incidence of treatment-emergent adverse events (including grades 3-4) were generally consistent with the initial HELIOS report. These long-term data support improved survival outcomes and deepening responses with ibrutinib+BR compared with BR in relapsed CLL/SLL.

Identification of critical members in a sulfidogenic benzene-degrading consortium by DNA stable isotope probing.

Stable isotope probing (SIP) was used to identify the active members in a benzene-degrading sulfidogenic consortium. SIP-terminal restriction fragment length polymorphism analysis indicated that a 270-bp peak incorporated the majority of the (13)C label and is a sequence closely related to that of clone SB-21 (GenBank accession no. AF029045). This target may be an important biomarker for anaerobic benzene degradation in the field.

X-ray crystal structure of proto-oncogene product c-Rel bound to the CD28 response element of IL-2.

BACKGROUND: The proto-oncogene product c-Rel is a Rel/NF-kappaB family transcription factor that plays a critical role in lymphoid cell development and mediates CD28-induced expression of interleukin 2 (IL-2). The CD28 response element (CD28RE) in the IL-2 enhancer is nonameric and similar to the kappaB DNA target sites recognized by p65 homodimers. RESULTS: We have determined and refined the X-ray crystal structure of the c-Rel homodimer complexed to the CD28RE DNA site, 5'-AGAAATTCC-3', to 2.85 A resolution. The c-Rel homodimer binds CD28RE in a mode similar to that observed in the p65/IL-8 kappaB crystallographic complex. Binding studies reveal that the c-Rel homodimer recognizes the CD28RE with higher affinity as compared to other canonical kappaB sequences despite the nonconsensus A:T base pair at the 5' end of the CD28RE. Preferential recognition of the CD28RE by c-Rel results from the direct contacts between the protein and the DNA as well as intrasubunit interactions between the beta(f)-beta(g) loop in the dimerization domain and the DNA-contacting loop L1 of the N-terminal domain. Not only do these loops have different conformations in other Rel/DNA crystallographic complexes, but they also contain two of the five oncogenic point mutations found in v-Rel. CONCLUSIONS: The current structure indicates that a non-DNA-contacting loop in the dimerization domain and the DNA-contacting loop L1 may play critical roles in defining affinity and specificity. Two amino acid changes in these segments may account for the differential DNA binding by v-Rel as compared to that of c-Rel.

Mitogenic and morphogenic effects of a bovine salivary gland extract on astrocytes and fibroblasts.

The presence of mitogenic and morphogenic activity in extracts of bovine salivary (parotid) glands is reported. The crude and partially purified extracts stimulated cultured rat cerebellar cells (astrocytes) and skin fibroblasts to undergo morphogenesis. The incorporation of [3H]thymidine was also stimulated in astrocytes, skin fibroblasts, and established fibroblastic cell lines. Growth-promoting activity was also demonstrated. The expression of maximum mitogenic activity in skin fibroblast cultures, but not kidney fibroblast cultures, required the presence of serum. The biological activity had an apparent native molecular weight greater than 230,000, was heat-sensitive, trypsin-resistant, and slightly sensitive to the action of papain.

CEPU-1 expression in the early embryonic chick brain.

We describe the expression pattern of CEPU-1, a cell adhesion molecule of the immunoglobulin superfamily, in the early chick embryo brain. An initially broad domain of expression, encompassing forebrain, midbrain and anterior hindbrain, is subsequently narrowed down to a ring-shaped domain at the midbrain-hindbrain boundary, co-localizing precisely with the expression of Wnt1 at the isthmus. In addition, CEPU-1 is expressed in the dorsal aspect of rhombomere 4 and its emigrating neural crest cells. Later in development, we also find CEPU-1 expression in other parts of the developing nervous system such as sensory ganglia and in the ventral aspect of forebrain, midbrain and hindbrain.

Cost-effectiveness of screening for hereditary hemochromatosis.

BACKGROUND: Recent studies have estimated the prevalence of hereditary hemochromatosis to be 3 to 8 per 1000. Early detection and treatment can prevent disease manifestations and normalize life expectancy. We used decision analysis techniques to determine whether screening the population at large for hereditary hemochromatosis would be cost-effective. METHODS: We constructed a model to compare the cost and outcome of a strategy of performing screening transferrin saturation tests on cohorts of 30-year old men with that of awaiting symptomatic disease. Baseline estimates of disease prevalence and complication rates were based on the published literature. Costs of treatment were estimated based on prevailing local costs. Sensitivity analyses were then conducted to determine which variables had the most significant impact on the decision to screen. RESULTS: At our baseline estimates, the decision to screen was found to be a dominant strategy and resulted in cost saving. Sensitivity analysis showed that four variables had the most significant impact on the decision to screen: (1) the prevalence of hereditary hemochromatosis, (2) the probability of developing disease manifestations, (3) the cost of the screening test, and (4) the discount rate. Screening was a dominant strategy for asymptomatic men provided that the prevalence of hereditary hemochromatosis was at least 3 per 1000, the probability of developing disease manifestations was greater than 0.4, the test cost was less than $12, and the discount rate was less than 3%. Using more pessimistic estimates, the cost per life year saved was still less than that considered acceptable for many common medical interventions. CONCLUSION: Screening for hereditary hemochromatosis has a favorable cost-effectiveness ratio over a wide range of assumptions. We recommend that practitioners consider including a serum transferrin saturation test in their routine screening for asymptomatic white men.

Psychopharmacological characterisation of the successive negative contrast effect in rats.

RATIONALE: Successive negative contrast (SNC) describes a change in the behaviour of an animal following a downshift in the quantitative or qualitative value of an expected reward. This behavioural response has been hypothesised to be linked to affective state, with negative states associated with larger and/or prolonged shifts in behaviour. OBJECTIVE: This study has investigated whether different psychopharmacological treatments have dissociable actions on the SNC effect in rats and related these findings to their actions on different neurotransmitter systems and affective state. METHODS: Animals were trained to perform a nose-poke response to obtain a high-value food reward (four pellets). SNC was quantified during devalue sessions in which the reward was reduced to one pellet. Using a within-subject study design, the effects of acute treatment with anxiolytic, anxiogenic, antidepressant and dopaminergic drugs were investigated during both baseline (four pellets) or devalue sessions (one pellet). RESULTS: The indirect dopamine agonist, amphetamine, attenuated the SNC effect whilst the D1/D2 antagonist, alpha-flupenthixol, potentiated it. The antidepressant citalopram, anxiolytic buspirone and anxiogenic FG7142 had no specific effects on SNC, although FG7142 induced general impairments at higher doses. The α2-adrenoceptor antagonist, yohimbine, increased premature responding but had no specific effect on SNC. Results for the anxiolytic diazepam were mixed with one group showing an attenuation of the SNC effect whilst the other showed no effect. CONCLUSIONS: These data suggest that the SNC effect is mediated, at least in part, by dopamine signalling. The SNC effect may also be attenuated by benzodiazepine anxiolytics.

Initial in vivo experience of pig artery patch transplantation in baboons using mutant MHC (CIITA-DN) pigs.

BACKGROUND: In the pig-to-nonimmunosuppressed baboon artery patch model, a graft from an α1,3-galactosyltransferase gene-knockout pig transgenic for human CD46 (GTKO/CD46) induces a significant adaptive immune response (elicited anti-pig antibody response, increase in T cell proliferation on MLR, cellular infiltration of the graft), which is effectively prevented by anti-CD154mAb-based therapy. METHODS: As anti-CD154mAb is currently not clinically applicable, we evaluated whether it could be replaced by CD28/B7 pathway blockade or by blockade of both pathways (using belatacept + anti-CD40mAb [2C10R4]). We further investigated whether a patch from a GTKO/CD46 pig with a mutant human MHC class II transactivator (CIITA-DN) gene would allow reduction in the immunosuppressive therapy administered. RESULTS: When grafts from GTKO/CD46 pigs were transplanted with blockade of both pathways, a minimal or insignificant adaptive response was documented. When a GTKO/CD46/CIITA-DN graft was transplanted, but no immunosuppressive therapy was administered, a marked adaptive response was documented. In the presence of CD28/B7 pathway blockade (abatacept or belatacept), there was a weak adaptive response that was diminished when compared with that to a GTKO/CD46 graft. Blockade of both pathways prevented an adaptive response. CONCLUSION: Although expression of the mutant MHC CIITA-DN gene was associated with a reduced adaptive immune response when immunosuppressive therapy was inadequate, when blockade of both the CD40/CD154 and CD28/B7 pathways was present, the response even to a GTKO/CD46 graft was suppressed. This was confirmed after GTKO/CD46 heart transplantation in baboons.

Postnatal regression of hypothalamic dopaminergic neurons in prolactin-deficient Snell dwarf mice.

Both Snell (Pit-1(dw) or (dwj), dw/dw) and Ames (Prophet of Pit-1(df), df/df) dwarf mice fail to produce prolactin (PRL) as well as GH due to deficient transcription factor Pit-1 activity and have reduced numbers of hypothalamic PRL-inhibiting area A12 tuberoinfundibular dopaminergic (TIDA) neurons. It has been reported that the TIDA deficit in Ames dwarf mice develops postnatally as a reduction in number after an initial increase that is comparable to that of normal siblings. The present study was designed to characterize A12 TIDA neuronal development in the Snell dwarf (dw/dw) compared with littermate normal mice. Brains of normal (DW/?) and dw(j)/dw(j) mice were examined at 7, 14, 21, 30, and > or = 60 postnatal days (d) by catecholamine fluorescence and quantification of neuron number after tyrosine hydroxylase immunostaining in dopaminergic (DA) areas A12, A13 (medial zona incerta), and A14 (periventricular nucleus). Fluorescence was less in dw/dw than in DW/? A12 perikarya and median eminence but was not reduced in other DA areas, such as substantia nigra, at all ages; A12 fluorescence was virtually absent in Snell dwarf adults. Numbers of TIDA neurons were comparable in normal and Snell dwarf mice at 7 d. In normal (DW/?) mice, A12 neurons increased in number to adult levels at 14 d and were significantly higher than in Snell dwarf (dw/dw) mice at 14 d (P < 0.05) and at subsequent ages (P < 0.01). In Snell dwarf mice, numbers of A12 neurons did not differ at 7, 14, and 21 d, decreased at 30 d (P < 0.05), and reached, at 60 d, 23% of the population in normal sibling mice (P < 0.01 compared with earlier ages). Neuron numbers in nonhypophysiotropic DA area A13 did not vary with age or phenotype. In A14, cell number was higher in both phenotypes at 14 d (P < 0.05 for DW/?; P < 0.01 for dw/dw); neuron number was lower in dw/dw than in DW/? mice at 30 d (P < 0.05) and 60 d (P < 0.01). Thus, compared with normal mice of the same strain, the A12 deficit is more severe in Snell (dw/dw) than in Ames (df/df) dwarf hypothalamus (48% of DF/?), as previously reported, and develops as a decline from the population present at 7 d rather than first increasing. A reduction in A14 neuron number also occurs in the Snell dwarf. Treatment of DW/dw- and dw/dw-containing litters with ovine PRL (50 mug/d, ip), beginning at 12 or 7 d and continuing until 42 d, resulted in TIDA neuron numbers in Snell dwarfs that were lower than those in normal siblings (P < 0.01 for both) but were higher than in untreated adult dwarfs and comparable to the TIDA population size in dwarfs at 7 d, indicating that PRL maintained this maximal number and prevented TIDA neuron dedifferentiation, which occurs in dwarf postnatal development.

Prolactin replacement during development prevents the dopaminergic deficit in hypothalamic arcuate nucleus in prolactin-deficient Ames dwarf mice.

PRL-deficient dwarf mice exhibit marked reduction in dopamine (DA) and in tyrosine hydroxylase (TH) immunoreactivity in the PRL-regulating neurons of the hypothalamic arcuate nucleus (catecholaminergic area A12). Recent studies in this laboratory have revealed that this condition develops postnatally, in that A12 DA fails to increase and the number of TH-positive cells decreases after 21 days of age. The present study was designed to test whether PRL replacement during the early postnatal period would increase DA and TH expression in dwarfs. Ames dwarf (df/df) and normal sibling (DF/?) mice were treated with daily injections of ovine PRL (50 micrograms, ip) or vehicle for 30 days starting on postnatal day 12. Brains were evaluated by catecholamine histofluorescence and TH immunocytochemistry at the end of the treatment period. TH-positive cells were counted in A12 and medial zona incerta (area A13) and also differentially within A12, in dorsal and ventral regions, and at anterior, middle, and posterior levels. Histofluorescence and TH-positive cell number (P < 0.01) in vehicle-treated dwarfs were greatly reduced compared with those in DF/? mice in A12, but not in A13. However, A12 fluorescence in PRL-treated dwarfs was comparable to that in DF/? mice. TH cell counts in A12 of PRL-treated dwarfs were significantly higher (P < 0.01) than those in vehicle-treated dwarfs and not different from those in either group of DF/? mice. Within A12, both dorsal and ventral TH cell numbers were reduced in vehicle-treated dwarfs (P < 0.01); the reduction was greater in the ventral subpopulation (P < 0.01). TH cell counts were lower in middle and posterior (P < 0.05), but not anterior, areas of A12 in vehicle-treated df/df mice compared with those in DF/? mice. TH cell numbers in all A12 regions in PRL-treated dwarfs were not different from those in DF/? mice. Thus, PRL replacement initiated before 2 weeks of age in dwarfs is effective in supporting DA and TH expression in both A12 neurons and median eminence external zone at normal levels, providing direct evidence that the DA/TH deficit in dwarfs is secondary to endogenous PRL deficiency.

Quantification of vasoactive intestinal peptide immunoreactivity in the anterior pituitary glands of intact male and female, ovariectomized, and estradiol benzoate-treated rats.

There are considerable data suggesting that vasoactive intestinal peptide (VIP) is involved in the regulation of PRL secretion; however, the role and cell of origin of anterior pituitary VIP remain to be determined. Immunocytochemical (ICC) studies have generally failed to detect VIP-immunoreactive (IR) cells in the pituitary of the untreated rat, although VIP-IR cells have been observed in the pituitaries of hypothyroid or estrogen-treated rats. This study was designed to examine the cellular distribution and tissue content of VIP in the anterior pituitary gland of rats under selected endocrine conditions known to alter the rates of PRL and VIP synthesis and secretion. To this end, anterior pituitary VIP and PRL content (ICC and RIA) and serum PRL levels were determined in ovariectomized (OVX) and OVX rats 3 days after treatment with 7 or 70 micrograms estradiol benzoate (EB). For comparison, pituitary VIP and PRL content (ICC and RIA) and serum PRL levels in untreated male and diestrous female rats were determined. Immunostaining for VIP was accomplished using a newly developed primary antiserum. Significant numbers of VIP-IR cells per 5-microns section were found in the anterior pituitary glands of all animals examined (275 +/- 33 in diestrous to 481 +/- 103 cells in male rats). VIP was not colocalized with PRL in any of the pituitaries regardless of steroid treatment or sex. Furthermore, the number of VIP-IR cells per pituitary gland was not significantly correlated with sex or EB treatment. Treatment with 70 micrograms, but not 7 micrograms, EB significantly increased the pituitary content of VIP and serum PRL levels compared to those after ovariectomy. However, both EB treatments resulted in a significant increase in pituitary PRL content compared to that in untreated OVX rats. Pituitaries from male rats had several-fold more VIP and less PRL content than pituitaries from diestrous rats. These data show that 1) in contrast to previous ICC studies, VIP-IR cells are readily detected in the anterior pituitary of intact male and female and OVX as well as EB-treated rats; 2) VIP is localized to cells other than lactotrophs, regardless of the steroid background; and 3) marked changes in anterior pituitary VIP content are not accompanied by changes in VIP-IR cell number.