Cloning of gonadotropin Gph-alpha, FSH-beta and LH-beta subunits and seasonal profiles of steroid hormones in wild-caught Nile perch, Lates niloticus

The Nile perch (np; Lates niloticus) is a freshwater teleost species with a potential for aquaculture in freshwater surroundings. However, wild-caught breeders have persistently failed to spawn spontaneously in captivity. Cloning of the gonadotropin subunits and analysing seasonal variation in reproductive hormone levels for a 1-year period were done to gain knowledge on the physiological basis underlying the reproductive biology of np. The β-follicle-stimulating hormone (FSH-β) and β-luteinizing hormone (LH-β) subunits and their common α-glycoprotein (Gph-α) subunit were cloned using 3' and 5' RACE-PCR. The nucleotide sequences of the npgph-α, npfsh-β, and nplh-β subunits were 664, 580 and 675 nucleotides in length, encoding peptides of 124, 120 and 148 amino acids, respectively. The deduced amino acid sequence of each mature subunit showed high similarity with its counterparts in other teleost. Sequence analysis showed that npFSH-β is more similar to higher vertebrate FSH-βs than to higher vertebrate LH-βs. Heterologous immunoassay was calibrated to analyse pituitary LH levels. While the LH immunoassay showed parallelism of npLH with that of tilapia (ta), no parallelism for FSH was found. Levels of pituitary LH were higher in females at gonadal stages of vitellogenic oocytes, mature secondary oocytes and mature tertiary oocytes with migrating nucleus than in pre-vitellogenic oocytes and early and late perinucleolus oocytes. Using competitive steroid ELISA, variations in the levels of the steroid hormones 11-ketotestosterone (11-KT) in males and E2 in females were characterized in relation to month and reproductive index of Nile perch. Our findings show that in females, gonadosomatic index and plasma E2 were highly correlated (R² = 0.699, n = 172) and peaked from September to November while in males, the gonadosomatic index and plasma 11-KT peaked from October to November. In female fish, both steroid hormones were detected in the plasma but greatly varied in concentrations. E2 in particular, increased with the developmental stage of the gonads. The levels of steroid hormones, E2 and 11-KT in females and males respectively increased with fish size (total lengths) and suggest that females mature at a body length of 40-59 cm than their counter part males that mature at a total length of 60-70 cm. Taken together, we describe seasonal endocrine differences in wild-caught adult Nile perch which could potentially be exploited to manipulate the reproductive axis in cultured breeders.

A half century of fish gonadotropin-releasing hormones: Breaking paradigms

The field of fish gonadotropin-releasing hormones (GnRHs) is also celebrating its 50th anniversary this year. This review provides a chronological history of fish GnRH biology over the past five decades. It demonstrates how discoveries in fish regarding GnRH and GnRH receptor multiplicity, dynamic interactions between GnRH neurons, and additional neuroendocrine factors acting alongside GnRH, amongst others, have driven a paradigm shift in our understanding of GnRH systems and functions in vertebrates, including mammals. The role of technological innovations in enabling scientific discoveries is portrayed, as well as how fundamental research in fish GnRH led to translational outcomes in aquaculture. The interchange between fish and mammalian GnRH research is discussed, as is the value and utility of using fish models for advancing GnRH biology. Current challenges and future perspectives are presented, with the hope of expanding the dialogue and collaborations within the neuroendocrinology scientific community at large, capitalizing on diversifying model animals and the use of comparative strategies.

Development of the gonadotropin-releasing hormone system

This review summarizes the current understanding of the development of the neuroendocrine gonadotropin-releasing hormone (GnRH) system, including discussion on open questions regarding (1) transcriptional regulation of the Gnrh1 gene; (2) prenatal development of the GnRH1 system in rodents and humans; and (3) paracrine and synaptic communication during migration of the GnRH cells.

Transcriptome of Distinct LH and FSH Cells Reveals Different Regulation Unique to Each Cell Type

From mammals to fish, gametogenesis and sexual maturation are driven by LH and FSH, the two gonadotropic hormones temporally secreted from the pituitary. Teleost fish are an excellent model for addressing the unique regulation and function of each gonadotropin hormone since, unlike mammals; they synthesize and secrete LH and FSH from distinct cells. By performing cell specific transcriptome analysis of double-labelled transgenic Nile tilapia (Oreochromis niloticus) expressing GFP and RFP in LH or FSH cells, respectively, we identified genes specifically enriched in each cell type. Though GnRH is considered the main neuropeptide regulating LH and FSH, we found that each LH and FSH cell express unique GPCR signature that reveals the direct regulation of additional metabolic and homeostatic hormones (like cholecystokinin, somatostatin and glutamate). Moreover, some of those GPCRs were conserved also in gonadotrophs of mammals (like PACAP receptor, Adropin receptor and GABBA receptor). Next, we had exploited the unique behavior of Nile tilapia where a behavioral hierarchy is created between males, to compare the gene expression in the pituitary and brain of dominant (reproducing) males to a subordinate (non-reproducing) males. By combining the two transcriptome sets we had identified novel players in the hypothalamic regulation of the HPG axis, and revealed how brain aromatase (cyp19a1b), that is enriched specifically in LH cells, is the key factor in regulating the activity of LH and FSH cells in dominant reproducing fish. Thereby, unraveling novel mechanisms in the differential regulation of LH and FSH. The research was funded by the Israel Science Foundation (ISF) no. 1540/17.

Synaptic communication mediates the assembly of a self-organizing circuit that controls reproduction

Migration of gonadotropin-releasing hormone (GnRH) neurons from their birthplace in the nasal placode to their hypothalamic destination is critical for vertebrate reproduction and species persistence. While their migration mode as individual GnRH neurons has been extensively studied, the role of GnRH-GnRH cell communication during migration remains largely unexplored. Here, we show in awake zebrafish larvae that migrating GnRH neurons pause at the nasal-forebrain junction and form clusters that act as interhemisphere neuronal ensembles. Within the ensembles, GnRH neurons create an isolated, spontaneously active circuit that is internally wired through monosynaptic glutamatergic synapses into which newborn GnRH neurons integrate before entering the brain. This initial phase of integration drives a phenotypic switch, which is essential for GnRH neurons to properly migrate toward their hypothalamic destination. Together, these experiments reveal a critical step for reproduction, which depends on synaptic communication between migrating GnRH neurons.

Functional Pituitary Networks in Vertebrates

The pituitary is a master endocrine gland that developed early in vertebrate evolution and therefore exists in all modern vertebrate classes. The last decade has transformed our view of this key organ. Traditionally, the pituitary has been viewed as a randomly organized collection of cells that respond to hypothalamic stimuli by secreting their content. However, recent studies have established that pituitary cells are organized in tightly wired large-scale networks that communicate with each other in both homo and heterotypic manners, allowing the gland to quickly adapt to changing physiological demands. These networks functionally decode and integrate the hypothalamic and systemic stimuli and serve to optimize the pituitary output into the generation of physiologically meaningful hormone pulses. The development of 3D imaging methods and transgenic models have allowed us to expand the research of functional pituitary networks into several vertebrate classes. Here we review the establishment of pituitary cell networks throughout vertebrate evolution and highlight the main perspectives and future directions needed to decipher the way by which pituitary networks serve to generate hormone pulses in vertebrates.

Ectopic over expression of kiss1 may compensate for the loss of kiss2

Kisspeptin (KISS) is a neuropeptide which plays a central role in the regulation of the hypothalamic-pituitary-gonadal axis, and is essential for sexual maturation and fertility in mammals. Unlike mammals, which possess only one KISS gene, two paralogous genes, kiss1 and kiss2, have been identified in zebrafish and other non-mammalian vertebrates. Previous studies suggest that Kiss2, but not Kiss1, is the reproduction relevant form amongst the two. To better understand the role of each of these isoforms in reproduction, a loss of function approach was applied. Two genetic manipulation techniques-clustered regularly interspaced short palindromic repeats (CRISPR) and transcription activator-like effector nucleases (TALEN)-were used to generate kiss1 and kiss2 knockout (KO) zebrafish lines, respectively. Examination of these KO lines showed that reproductive capability was not impaired, confirming earlier observations. Further analysis revealed that KO of kiss2 caused a significant increase in expression levels of kiss1, kiss2r and tac3a, while KO of kiss1 had no effect on the expression of any of the examined genes. In situ hybridization analysis revealed that kiss1 mRNA is expressed only in the habenula in wild type brains, while in kiss2 KO fish, kiss1 mRNA-expressing cells were identified also in the ventral telencephalon, the ventral part of the entopeduncular nucleus, and the dorsal and ventral hypothalamus. Interestingly, these regions are known to express kiss2r, and the ventral hypothalamus normally expresses kiss2. These results suggest that a compensatory mechanism, involving ectopic kiss1 expression, takes place in the kiss2 KO fish, which may substitute for Kiss2 activity.

Regulation of CHD2 expression by the Chaserr long noncoding RNA gene is essential for viability

Chromodomain helicase DNA binding protein 2 (Chd2) is a chromatin remodeller implicated in neurological disease. Here we show that Chaserr, a highly conserved long noncoding RNA transcribed from a region near the transcription start site of Chd2 and on the same strand, acts in concert with the CHD2 protein to maintain proper Chd2 expression levels. Loss of Chaserr in mice leads to early postnatal lethality in homozygous mice, and severe growth retardation in heterozygotes. Mechanistically, loss of Chaserr leads to substantially increased Chd2 mRNA and protein levels, which in turn lead to transcriptional interference by inhibiting promoters found downstream of highly expressed genes. We further show that Chaserr production represses Chd2 expression solely in cis, and that the phenotypic consequences of Chaserr loss are rescued when Chd2 is perturbed as well. Targeting Chaserr is thus a potential strategy for increasing CHD2 levels in haploinsufficient individuals.

Toolbox: Creating a systematic database of secretory pathway proteins uncovers new cargo for COPI

A third of yeast genes encode for proteins that function in the endomembrane system. However, the precise localization for many of these proteins is still uncertain. Here, we visualized a collection of ~500 N‐terminally, green fluorescent protein (GFP), tagged proteins of the yeast Saccharomyces cerevisiae. By co‐localizing them with 7 known markers of endomembrane compartments we determined the localization for over 200 of them. Using this approach, we create a systematic database of the various secretory compartments and identify several new residents. Focusing in, we now suggest that Lam5 resides in contact sites between the endoplasmic reticulum and the late Golgi. Additionally, analysis of interactions between the COPI coat and co‐localizing proteins from our screen identifies a subset of proteins that are COPI‐cargo. In summary, our approach defines the protein roster within each compartment enabling characterization of the physical and functional organization of the endomembrane system and its components.

Transcriptional Heterogeneity of Beta Cells in the Intact Pancreas

Pancreatic beta cells have been shown to be heterogeneous at multiple levels. However, spatially interrogating transcriptional heterogeneity in the intact tissue has been challenging. Here, we developed an optimized protocol for single-molecule transcript imaging in the intact pancreas and used it to identify a sub-population of "extreme" beta cells with elevated mRNA levels of insulin and other secretory genes. Extreme beta cells contain higher ribosomal and proinsulin content but lower levels of insulin protein in fasted states, suggesting they may be tuned for basal insulin secretion. They exhibit a distinctive intra-cellular polarization pattern, with elevated mRNA concentrations in an apical ER-enriched compartment, distinct from the localization of nascent and mature proteins. The proportion of extreme cells increases in db/db diabetic mice, potentially facilitating the required increase in basal insulin. Our results thus highlight a sub-population of beta cells that may carry distinct functional roles along physiological and pathological timescales.

Characterization of carp gonadotropins: Structure, annual profile, and carp and zebrafish pituitary topographic organization

Two gonadotropins, follicle stimulating hormone (FSH) and luteinizing hormone (LH), are important players in the hypothalamic-pituitary-gonadal axis of vertebrates. In the present work, we describe the construction of recombinant (r) common carp (Cyprinus carpio; c) FSH (rcFSH) and LH (rcLH) using the Pichia pastoris system, the generation of specific antibodies against their respective β subunits, and their use in the development and validation of specific ELISAs. We produced carp rLH and rFSH as single-chain polypeptides, wherein the GTH subunit α was joined with either cLHβ or cFSHβ mature protein-coding sequences to form a fusion gene that encodes a yoked polypeptide, in which the GTH β-subunit forms the N-terminal part and the α-subunit forms the C-terminal part. Competitive ELISAs were developed, using primary antibodies against rcLHβ or rcFSHβ, respectively, and rcLHβα or rcFSHβα for the standard curves. The standard curves for cLH paralleled those of pituitary extracts of the homologous fish and also those of other cyprinids species like the black carp (Mylopharyngodon piceus), goldfish (Carassius auratus), silver carp (Hypophthalmichthys molitrix), and grass carp (Ctenopharyngodon idella). We used the specific antibodies raised against cFSH and cLH to study the specific localization of the different GTH cells in the pituitary of carp and its taxonomic relative species - the zebrafish. Both FSH and LH cells are localized in the center of the proximal pars distalis enveloping both sides of the neurohypophysis. LH cells form a continuous population throughout the PPD, while FSH cells are more loosely distributed throughout the same area and form small aggregations. Marked annual changes were encountered in gonadosomatic index (GSI), follicle diameter, mRNA levels and protein levels of FSH and LH. From September to November, all fish had low GSI, and the ovary contained previtellogenic follicles. From December, the GSI level increased and remained high until March, the follicular diameter reached its maximum in January, where the ovary contained large fully grown follicles. Thereafter, spawning occurred through March and April and ended in May, and GSI level and follicle diameter increased again; and the ovary contained mid-vitellogenic follicles. LH pituitary content and mRNA levels were low at pre- and early vitellogenesis, increasing gradually during this process to reach a peak of LH mRNA levels in mid vitellogenic ovary and a peak of LH content in fully grown ovarian follicles. However, no significant change occurred in FSH pituitary content and mRNA levels in vitellogenic fish and in fish during final maturation stages. A dramatic difference was found in the total content of each gonadotropin in the pituitary, with higher LH than FSH. Moreover, follicle diameter was positively and significantly correlated with LH pituitary content and its transcript levels - but not with the pituitary content or mRNA levels of FSH. Taken together, these results indicate that in carp, LH alone is sufficient to regulate both vitellogenesis and final oocyte maturation while FSH may have another, yet undefined role.

The gonadotropin-inhibitory hormone (Lpxrfa) system's regulation of reproduction in the brain-pituitary axis of the zebrafish (Danio rerio)

Gonadotropin-inhibitory hormone (GNIH) was discovered in quail with the ability to reduce gonadotropin expression/secretion in the pituitary. There have been few studies on GNIH orthologs in teleosts (LPXRFamide (Lpxrfa) peptides), which have provided inconsistent results. Therefore, the goal of this study was to determine the roles and modes of action by which Lpxrfa exerts its functions in the brain-pituitary axis of zebrafish (Danio rerio). We localized Lpxrfa soma to the ventral hypothalamus, with fibers extending throughout the brain and to the pituitary. In the preoptic area, Lpxrfa fibers interact with gonadotropin-releasing hormone 3 (Gnrh3) soma. In pituitary explants, zebrafish peptide Lpxrfa-3 downregulated luteinizing hormone beta subunit and common alpha subunit expression. In addition, Lpxrfa-3 reduced gnrh3 expression in brain slices, offering another pathway for Lpxrfa to exert its effects on reproduction. Receptor activation studies, in a heterologous cell-based system, revealed that all three zebrafish Lpxrfa peptides activate Lpxrf-R2 and Lpxrf-R3 via the PKA/cAMP pathway. Receptor activation studies demonstrated that, in addition to activating Lpxrf receptors, zebrafish Lpxrfa-2 and Lpxrfa-3 antagonize Kisspeptin-2 (Kiss2) activation of Kisspeptin receptor-1a (Kiss1ra). The fact that kiss1ra-expressing neurons in the preoptic area are innervated by Lpxrfa-ir fibers suggests an additional pathway for Lpxrfa action. Therefore, our results suggest that Lpxrfa may act as a reproductive inhibitory neuropeptide in the zebrafish that interacts with Gnrh3 neurons in the brain and with gonadotropes in the pituitary, while also potentially utilizing the Kiss2/Kiss1ra pathway.

Global mRNA polarization regulates translation efficiency in the intestinal epithelium

Asymmetric messenger RNA (mRNA) localization facilitates efficient translation in cells such as neurons and fibroblasts. However, the extent and importance of mRNA polarization in epithelial tissues are unclear. Here, we used single-molecule transcript imaging and subcellular transcriptomics to uncover global apical-basal intracellular polarization of mRNA in the mouse intestinal epithelium. The localization of mRNAs did not generally overlap protein localization. Instead, ribosomes were more abundant on the apical sides, and apical transcripts were consequently more efficiently translated. Refeeding of fasted mice elicited a basal-to-apical shift in polarization of mRNAs encoding ribosomal proteins, which was associated with a specific boost in their translation. This led to increased protein production, required for efficient nutrient absorption. These findings reveal a posttranscriptional regulatory mechanism involving dynamic polarization of mRNA and polarized translation.

Gonadotropins in the Russian Sturgeon: Their Role in Steroid Secretion and the Effect of Hormonal Treatment on Their Secretion

In the reproduction process of male and female fish, pituitary derived gonadotropins (GTHs) play a key role. To be able to specifically investigate certain functions of Luteinizing (LH) and Follicle stimulating hormone (FSH) in Russian sturgeon (Acipenser gueldenstaedtii; st), we produced recombinant variants of the hormones using the yeast Pichia pastoris as a protein production system. We accomplished to create in vitro biologically active heterodimeric glycoproteins consisting of two associated α- and β-subunits in sufficient quantities. Three dimensional modelling of both GTHs was conducted in order to study the differences between the two GTHs. Antibodies were produced against the unique β-subunit of each of the GTHs, in order to be used for immunohistochemical analysis and to develop an ELISA for blood and pituitary hormone quantification. This detection technique revealed the specific localization of the LH and FSH cells in the sturgeon pituitary and pointed out that both cell types are present in substantially higher numbers in mature males and females, compared to immature fish. With the newly attained option to prevent cross-contamination when investigating on the effects of GTH administration, we compared the steroidogeneic response (estradiol and 11-Keto testosterone (11-KT) in female and males, respectively) of recombinant stLH, stFSH, and carp pituitary extract in male and female sturgeon gonads at different developmental stages. Finally, we injected commercially available gonadotropin releasing hormones analog (GnRH) to mature females, and found a moderate effect on the development of ovarian follicles. Application of only testosterone (T) resulted in a significant increase in circulating levels of 11-KT whereas the combination of GnRH + T did not affect steroid levels at all. The response pattern for estradiol demonstrated a similar situation. FSH levels showed significant increases when GnRH + T was administered, while no changes were present in LH levels.

Anatomical and functional gonadotrope networks in the teleost pituitary

Mammalian pituitaries exhibit a high degree of intercellular coordination; this enables them to mount large-scale coordinated responses to various physiological stimuli. This type of communication has not been adequately demonstrated in teleost pituitaries, which exhibit direct hypothalamic innervation and expression of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in distinct cell types. We found that in two fish species, namely tilapia and zebrafish, LH cells exhibit close cell-cell contacts and form a continuous network throughout the gland. FSH cells were more loosely distributed but maintained some degree of cell-cell contact by virtue of cytoplasmic processes. These anatomical differences also manifest themselves at the functional level as evidenced by the effect of gap-junction uncouplers on gonadotropin release. These substances abolished the LH response to gonadotropin-releasing hormone stimulation but did not affect the FSH response to the same stimuli. Dye transfer between neighboring LH cells provides further evidence for functional coupling. The two gonadotropins were also found to be differently packaged within their corresponding cell types. Our findings highlight the evolutionary origin of pituitary cell networks and demonstrate how the different levels of cell-cell coordination within the LH and FSH cell populations are reflected in their distinct secretion patterns.

Distribution of LPXRFa, a gonadotropin-inhibitory hormone ortholog peptide, and LPXRFa receptor in the brain and pituitary of the tilapia

In vertebrates, gonadotropin-releasing hormone (GnRH) and gonadotropin-inhibitory hormone (GnIH), respectively, regulate reproduction in positive and negative manners. GnIH belongs to the LPXRFa family of peptides previously identified in mammalian and nonmammalian vertebrates. Studying the detailed distribution of LPXRFa as well as its receptor (LPXRFa-R) in the brain and pituitary is important for understanding their multiple action sites and potential functions. However, the distribution of LPXRFa and LPXRFa-R has not been studied in teleost species, partially because of the lack of fish-specific antibodies. Therefore, in the present study, we generated specific antibodies against LPXRFa and its receptor from Nile tilapia (Oreochromis niloticus), and examined their distributions in the brain and pituitary by immunohistochemistry. Tilapia LPXRFa-immunoreactive neurons lie in the posterior ventricular nucleus of the caudal preoptic area, whereas LPXRFa-R-immunoreactive cells are distributed widely. Double immunofluorescence showed that neither LPXRFa-immunoreactive fibers nor LPXRFa-R is closely associated or coexpressed with GnRH1, GnRH3, or kisspeptin (Kiss2) neurons. In the pituitary, LPXRFa fibers are closely associated with gonadotropic endocrine cells [expressing luteinizing hormone (LH) and follicle-stimulating hormone (FSH)], with adrenocorticomelanotropic cells [corticotropin (ACTH) and α-melanotropin (α-MSH)], and with somatolactin endocrine cells. In contrast, LPXRFa-R are expressed only in LH, ACTH, and α-MSH cells. These results suggest that LPXRFa and LPXRFa-R signaling acts directly on the pituitary cells independent from GnRH or kisspeptin and could play multiple roles in reproductive and nonreproductive functions in teleosts. J. Comp. Neurol. 524:2753-2775, 2016. © 2016 Wiley Periodicals, Inc.

Architecture of GnRH-Gonadotrope-Vasculature Reveals a Dual Mode of Gonadotropin Regulation in Fish

The function and components of the hypothalamic-pituitary axis are conserved among vertebrates; however, in fish, a neuroglandular mode of delivery (direct contact between axons and endocrine cells) was considered dominant, whereas in tetrapods hypothalamic signals are relayed to their targets via the hypophysial portal blood system (neurovascular delivery mode). By using a transgenic zebrafish model we studied the functional and anatomical aspects of gonadotrope regulation thus revisiting the existing model. FSH cells were found to be situated close to the vasculature whereas the compact organization of LH cells prevented direct contact of all cells with the circulation. GnRH3 fibers formed multiple boutons upon reaching the pituitary, but most of these structures were located in the neurohypophysis rather than adjacent to gonadotropes. A close association was observed between FSH cells and GnRH3 boutons, but only a fifth of the LH cells were in direct contact with GnRH3 axons, suggesting that FSH cells are more directly regulated than LH cells. GnRH3 fibers closely followed the vasculature in the neurohypophysis and formed numerous boutons along these tracts. These vessels were found to be permeable to relatively large molecules, suggesting the uptake of GnRH3 peptides. Our findings have important implications regarding the differential regulation of LH and FSH and contradict the accepted notion that fish pituitary cells are mostly regulated directly by hypothalamic fibers. Instead, we provide evidence that zebrafish apply a dual mode of gonadotrope regulation by GnRH3 that combines both neuroglandular and neurovascular components.

Direct regulation of gonadotropin release by neurokinin B in tilapia (Oreochromis niloticus)

Neurokinin B (NKB) was recently identified as a key regulator of reproduction in mammals and fish. Fish were found to possess a specific novel neurokinin termed NKF. To study the role of NKB/NKF in the regulation of fish reproduction and to investigate the role of NKB/NKF and their receptors in the piscine pituitary, we have identified the NKB/tachikinin 3 receptor (tac3r) system in tilapia. Bioinformatics and phylogenetic analyses have demonstrated that the tilapia holds 1 putative tac3 gene and 2 NKB receptor genes (tac3ra and tac3rb) that clustered with other piscine Tac3 and NKB receptor lineages. Furthermore, we found that in African cichlids, NKB peptides differ from other vertebrate NKBs in their C-terminal sequence, possessing isoleucine instead of valine as the X in the NKB FXGLM-NH2-terminal consensus sequence. Signal transduction analysis demonstrated that tilapia NKB (tiNKB), tiNKF, and human NKB activated both CRE-luc and SRE-luc transcriptional activity of both tilapia and human NKB receptors. Two hours after ip injection of tiNKB, the plasma levels of both FSH and LH were increased, whereas tiNKF was more effective in increasing LH levels. However, tiNKB was more effective than tiNKF in increasing both FSH and LH from tilapia pituitary dispersed cells. Using in situ hybridization and fluorescent immunohistochemistry, we have shown that LH cells possess tac3, tac3ra, and tac3rb mRNAs, whereas FSH cells possess mainly tac3rb and tac3ra and tac3 to a much lesser extent. These results suggest that the members of the NKB/tac3r system may serve as paracrine/autocrine regulators of gonadotropin release in fish pituitary.

LPXRFa, the piscine ortholog of GnIH, and LPXRF receptor positively regulate gonadotropin secretion in Tilapia (Oreochromis niloticus)

LPXRFamide (LPXRFa) peptides have been characterized for their ability to inhibit gonadotropin (GTH) release in birds and stimulate growth hormone (GH) release in frogs. However, their involvement in regulating the reproductive hypothalamo-pituitary-gonadal axis in mammals and fish is inconclusive. To study the role of LPXRFa peptides in the regulation of GTH secretion, we cloned tilapia LPXRFa and LPXRF receptor (LPXRF-R). Processing of the tilapia preproLPXRFa liberated three mature LPXRFa peptides that varied in size and post-translational modifications. Phylogenetic analysis of LPXRFa and the closely related RFamide peptide PQRFa showed clear clustering of each peptide sequence with its orthologs from various vertebrates. Signal-transduction analysis of the tilapia LPXRF-R in COS-7 cells showed clear stimulation of CRE-dependent luciferase activity, whereas the human NPFFR1 showed suppression of forskolin-induced CRE-dependent activity in this system. Administration of the tilapia pyroglutaminated LPXRFa-2 peptide to primary cell culture of tilapia pituitaries, or to reproductive female tilapia by ip injection, positively regulated both LH and FSH release in vivo and in vitro. Using double-labeled fluorescent in-situ hybridization and immunofluorescence, βLH cells were found to co-express both tilapia lpxrf and tilapia lpxrf-r mRNA, whereas some of the βFSH cells coexpressed only lpxrf-r mRNA. No coexpression of tilapia lpxrf-r was identified in GH-positive cells. These findings suggest that the LPXRFa system is a potent positive regulator of the reproductive neuroendocrine axis of tilapia.

Long-term GnRH-induced gonadotropin secretion in a novel hypothalamo-pituitary slice culture from tilapia brain

Organotypic cultures, prepared from hypothalamo-pituitary slices of tilapia, were developed to enable long-term study of secretory cells in the pituitary of a teleost. Values of membrane potential at rest were similar to those recorded from acute slices, and cells presented similar spontaneous spikes and spikelets. Some cells also exhibited slow spontaneous oscillations in membrane potential, which may be network-driven. Long-term (6days) continuous exposure to GnRH induced increases in LH and FSH secretion. FSH levels reached the highest levels after 24h of exposure to GnRH, and the highest secretion of LH was observed in days 4 and 5 of the experiment. Since slices were viable for several weeks in culture, maintaining the original cytoarchitecture, electrical membrane properties and the ability to secrete hormones in response to exogenous GnRH, this technique is ideal for studying the mechanisms regulating cell-to-cell communication under conditions resembling the in vivo tissue organization.

Artificial masculinization in tilapia involves androgen receptor activation

Estrogens have a pivotal role in natural female sexual differentiation of tilapia while lack of steroids results in testicular development. Despite the fact that androgens do not participate in natural sex differentiation, synthetic androgens, mainly 17-α-methyltestosterone (MT) are effective in the production of all-male fish in aquaculture. The sex inversion potency of synthetic androgens may arise from their androgenic activity or else as inhibitors of aromatase activity. The current study is an attempt to differentiate between the two alleged activities in order to evaluate their contribution to the sex inversion process and aid the search for novel sex inversion agents. In the present study, MT inhibited aromatase activity, when applied in vitro as did the non-aromatizable androgen dihydrotestosterone (DHT). In comparison, exposure to fadrozole, a specific aromatase inhibitor, was considerably more effective. Androgenic activity of MT was evaluated by exposure of Sciaenochromis fryeri fry to the substance and testing for the appearance of blue color. Flutamide, an androgen antagonist, administered concomitantly with MT, reduced the appearance of the blue color and the sex inversion potency of MT in a dose-dependent manner. In tilapia, administration of MT, fadrozole or DHT resulted in efficient sex inversion while flutamide reduced the sex inversion potency of all three compounds. In the case of MT and DHT the decrease in sex inversion efficiency caused by flutamide is most likely due to the direct blocking of the androgen binding to its cognate receptor. The negative effect of flutamide on the efficiency of the fadrozole treatment may indicate that the masculinizing activity of fadrozole may be attributed to excess, un-aromatized, androgens accumulated in the differentiating gonad. The present study shows that when androgen receptors are blocked, there is a reduction in the efficiency of sex inversion treatments. Our results suggest that in contrast to natural sex differentiation, during sex inversion treatments, androgens, either endogenous or exogenous, participate in inducing testicular differentiation.

The medio-basal hypothalamus as a dynamic and plastic reproduction-related kisspeptin-gnrh-pituitary center in fish

Kisspeptin regulates reproductive events, including puberty and ovulation, primarily via GnRH neurons. Prolonged treatment of prepubertal striped bass females with kisspeptin (Kiss) 1 or Kiss2 peptides failed to enhance puberty but suggested a gnrh-independent pituitary control pathway. Kiss2 inhibited, but Kiss1 stimulated, FShβ expression and gonadal development, although hypophysiotropic gnrh1 and gnrh receptor expression remained unchanged. In situ hybridization and immunohistochemistry on brains and pituitaries revealed a differential plasticity between the 2 kisspeptin neurons. The differences were most pronounced at the prespawning phase in 2 regions along the path of gnrh1 axons: the nucleus lateralis tuberis (NLT) and the neurohypophysis. Kiss1 neurons appeared in the NLT and innervated the neurohypophysis of prespawning males and females, reaching Lh gonadotropes in the proximal pars distalis. Males, at all reproductive stages, had Kiss2 innervations in the NLT and the neurohypophysis, forming large axonal bundles in the former and intermingling with gnrh1 axons. Unlike in males, only preovulatory females had massive NLT-neurohypophysis staining of kiss2. Kiss2 neurons showed a distinct appearance in the NLT pars ventralis-equivalent region only in spawning zebrafish, indicating that this phenomenon is widespread. These results underscore the NLT as important nuclei for kisspeptin action in 2 facets: 1) kisspeptin-gnrh interaction, both kisspeptins are involved in the regulation of gnrh release, in a stage- and sex-dependent manner, especially at the prespawning phase; and 2) gnrh-independent effect of Kiss peptides on the pituitary, which together with the plastic nature of their neuronal projections to the pituitary implies that a direct gonadotropic regulation is plausible.

Fifteen years of the Family Eating and Activity Habits Questionnaire (FEAHQ): an update and review

BACKGROUND

The Family Eating and Activity Habits Questionnaire (FEAHQ) is a 32-item self-report instrument designed to assess the eating and activity habits of family members as well as obesogenic factors in the overall home environment (stimulus and behaviour patterns) related to weight. Originally, this questionnaire, which was developed in Israel, was designed for use in family-based weight-management interventions that emphasized changes in the environment, and in parents' knowledge, behaviours and modelling. It was developed for use with children aged 6-11 years and designed for co-completion by parents or caretakers and their children. Over the years, it has been administered in research and clinical settings in Israel, England, Australia and other countries. Its 15-year anniversary calls for an update in the literature regarding adjustments made to improve its use in different settings and with different ethnic populations and the psychometric properties of the revised version.

OBJECTIVE

The goal of this paper is threefold: (i) to describe the history and development of the FEAHQ; (ii) to present new data supporting the psychometric properties of the subscales of the Revised FEAHQ (FEAHQ-R) for ages 6-12 years and (iii) to review the clinical and research literature reporting on FEAHQ subscales.

METHODS

The psychometric properties of the revised questionnaire were evaluated in a randomized control trial and in a naturalistic, community-based study to promote healthy lifestyle among families with children 6-12 years of age from different ethnic populations.

RESULTS

The tool demonstrated good test-retest reliability when completed by caretakers and very good internal consistency. The questionnaire scores discriminated between obese and normal-weight children and predicted the weight classification of 66% of the participants.

CONCLUSIONS

The FEAHQ-R is a useful clinical tool for identifying target behaviors for treatment and monitoring treatment progress that centers on overweight prevention and weight management.

A novel model for development, organization, and function of gonadotropes in fish pituitary

The gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are key regulators of the reproductive axis in vertebrates. Despite the high popularity of zebrafish as a model organism for studying reproductive functions, to date no transgenic zebrafish with labeled gonadotropes have been introduced. Using gonadotropin regulatory elements from tilapia, we generated two transgenic zebrafish lines with labeled gonadotropes. The tilapia and zebrafish regulatory sequences were highly divergent but several conserved elements allowed the tilapia promoters to correctly drive the transgenes in zebrafish pituitaries. FSH cells reacted to stimulation with gonadotropin releasing hormone by proliferating and showing increased transgene fluorescence, whereas estrogen exposure caused a decrease in cell number and transgene fluorescence. Transgene fluorescence reflected the expression pattern of the endogenous fshb gene. Ontogenetic expression of the transgenes followed typical patterns, with FSH cells appearing early in development, and LH cells appearing later and increasing dramatically in number with the onset of puberty. Our transgenic lines provide a powerful tool for investigating the development, anatomy, and function of the reproductive axis in lower vertebrates.

Social dominance in tilapia is associated with gonadotroph hyperplasia

Tilapias are emerging as one of the most important fish in worldwide aquaculture and are also widely used as model fish in the study of reproduction and behavior. During the reproductive season, male tilapia are highly territorial and form spawning pits in which the dominant males court and spawn with available females. Non-territorial males stand a much lower chance of reproducing. Using transgenic tilapia in which follicle stimulating hormone (FSH) gonadotrophs were fluorescently labeled with enhanced green fluorescent protein (EGFP), we studied the effect of social dominance on the hormonal profile and pituitary cell populations in dominant and non-dominant males. Immunofluorescence studies showed that FSH-EGFP-transgenic fish reliably express EGFP in FSH-secreting cells. EGFP expression pattern differed from that of luteinizing hormone. Dominant males had larger gonads as well as higher levels of androgens and gonadotropins in the plasma. Pituitaries of dominant males exhibited higher gonadotropin content and gene expression. Flow cytometry revealed pituitary hyperplasia as well as FSH cell hyperplasia and increased granulation. Taken together, these findings suggest that gonadotroph hyperplasia as well as increased production by individual cells underlie the increased reproductive activity of dominant tilapia males.

Mitochondrial VDAC1: function in cell life and death and a target for cancer therapy

Found at the outer mitochondrial membrane, the voltage-dependent anion channel, VDAC, assumes a crucial position in the cell, serving as the main interface between mitochondrial and cellular metabolisms by mediating transport of ions and metabolites. VDAC thus functions as a gatekeeper, controlling cross-talk between mitochondria and the rest of the cell. Moreover, its location at the boundary between the mitochondria and the cytosol enables VDAC to interact with proteins that mediate and regulate the integration of mitochondrial functions with other cellular activities. Here, we review current knowledge related to the roles played by VDAC in the regulation of cell life and cell death, with relation to cancer. The current concepts of altered metabolism in cancer cells are presented with specific emphasis on mitochondrial, more specifically VDAC1-bound hexokinase (HK), facilitating and promoting the high glycolytic tumor phenotype. In this respect, the up-regulation of HK expression in tumor cells and its binding to VDAC provide both a metabolic benefit and apoptosis-suppressive capacity that offers the cell a growth advantage and increases its resistance to chemotherapy. VDAC has also been recognized as a key protein in mitochondria-mediated apoptosis since it is the proposed target for the pro- and antiapoptotic Bcl-2-family of proteins, as well as due to its function in the release of apoptotic proteins located in the inter-membranal space. These and other functions point to VDAC1 as being a rational target for the development of a new generation of therapeutics.

Protective self-presentation style: association with disordered eating and anorexia nervosa mediated by sociocultural attitudes towards appearance

OBJECTIVE

We tested the hypothesis that a protective self-presentation style (Lennox and Wolfe, 1984) is associated with eating pathology and anorexia nervosa (AN) and that this association is mediated by sociocultural attitudes towards appearance emphasizing the thin ideal.

METHOD

We compared the protective-presentation style of women with AN (N=17), partially recovered women (N=110), fully recovered women (N=73), and female controls (N=374).

RESULTS

Ill women had a more protective self-presentation style than partially or fully recovered women, who in turn had a more protective self-presentation style than controls. Sociocultural attitudes towards appearance fully mediated the association between protective self-presentation and disordered eating.

CONCLUSIONS

Protective self-presentation may therefore be a risk factor for AN and/or a prognostic factor. Implications for therapy and prevention are discussed.

[Criteria for hospitalization of adolescents with anorexia nervosa according to postmodernistic approach]

The increased incidence of eating disorders in the Western world raises the demand for discussion regarding recommendations for hospitalization of adolescents with these disorders. The American Psychiatric Association has established criteria for hospitalization that include physiological, psychological and social components. The societal and professional discussion regarding adolescent hospitalization is frequently based on obvious assumptions and accepted discourses, such as the hierarchical pattern in the medical model, the control perception, knowledge ownership, freedom of choice, etc. These issues challenge the discussion on the hospitalization of adolescents with eating disorders. Eating disorders involve dimensions of control, boundaries, and psychological space, which are the essence of the difference between therapy in hospital or in the community. Personality and personal patterns, as well as associated psychopathology, family structure and other factors influence these dimensions and the ability of teenagers to be helped by the professional frameworks approached by them. This manuscript raises questions in relation to issues regarding hospitalization based on conflicts unique to eating disorders.

Tilapia Follicle-Stimulating Hormone (FSH): Immunochemistry, Stimulation by Gonadotropin-Releasing Hormone, and Effect of Biologically Active Recombinant FSH on Steroid Secretion1

In fish, FSH is generally important for early gonadal development and vitellogenesis. As in mammals, FSH is a heterodimer composed of an alpha subunit that is noncovalently associated with the hormone-specific beta subunit. The objective of the present study was to express glycosylated, properly folded, and biologically active tilapia FSH (tFSH) using the Pichia pastoris expression system. Using this material, we aimed to develop a specific ELISA and to enable the study of FSH response to GnRH. The methylotrophic yeast P. pastoris was used to coexpress recombinant genes formed by fusion of mating factor alpha leader and tilapia fshb and cga coding sequences. Western blot analysis of tilapia pituitary FSH, resolved by SDS-PAGE, yielded a band of 15 kDa, while recombinant tFSH beta (rtFSH beta) and rtFSH beta alpha had molecular masses of 17-18 kDa and 26-30 kDa, respectively. Recombinant tFSH beta alpha was found to bear only N-linked carbohydrates. Recombinant tFSH beta alpha significantly enhanced 11-ketotestosterone (11-KT) and estradiol secretion from tilapia testes and ovaries, respectively, in a dose-dependent manner (similar to tilapia pituitary extract, affinity-purified pituitary FSH, and porcine FSH). Using antibodies raised against rtFSH beta, FSH-containing cells were localized adjacent to hypothalamic nerve fibers ramifying in the proximal pars distalis (PPD), while LH cells were localized in a more peripheral region of the PPD. Moreover, FSH is under the control of hypothalamic decapeptide GnRH, an effect that was abolished through the use of specific bioneutralizing antisera, anti-rtFSH beta. It also reduced basal secretion of 11-KT.

The -22c/t polymorphism in presenilin 1 gene is not connected with late-onset and early-onset familial Alzheimer's disease in Poland

The -22c/t polymorphism in the promoter of the presenilin 1 gene is associated with increased risk for Alzheimer's disease (AD) in some populations. It was shown that -22c allele is connected with two-fold decrease in promoter activity. We studied the impact of the polymorphism in groups of Polish late-onset and early-onset AD patients. Our results suggest that -22c/t polymorphism is not connected with AD in Polish population. The -22t allele showed a high degree of linkage disequilibrium with -2797 insertion of 13 bp. An additional -2923g/t polymorphism is also not connected with -22c/t and is not a risk factor for AD.

[Clinical mentorship as a bridge to life in the treatment of eating disorders]

The aim of this article is to describe a community-based multi-modality intensive treatment program, which demonstrates a significant reduction in symptoms of eating disorders while providing an opportunity to deal with the functional and social skills. Treatment is delivered through a multidisciplinary team. The uniqueness of the team is in the inclusion of clinical mentors. These are social workers, art therapists and graduate level psychology students who are trained to connect with clients in an informal, intensive manner (10-40 hours a week). The mentors focus on legitimizing healthy attitudes to food, eating and life, while highlighting the pain and loss associated with the disorder. The mentors serve as meal companion and calming figure, representing the healthy self-caring voice. The relationship established during the many hours spent together becomes a powerful experience, completely different from the isolation of the disorder. The treatment intervenes in most areas of life, focusing on an active search for possibilities, in contrast to the emptiness associated with the disorder. This article presents the results and principles of a 2.5-year practice. Seventeen patients, ill for 6 years and more, completed this program more than a year ago. An assessment of their BMI and their general outcome using Eckert scales was performed. One year after completing the program, 76% of the patients were defined as recovered and 12% were almost recovered with only a few remaining symptoms. All of these patients function satisfactorily in the community, both in social and occupational aspects. Six percent were partially recovered and 6% suffered from regression during the first year of follow-up. This treatment provides the intensity required in hospitalizations, while enabling patients to stay in the community and maintain those activities that survive the disorder. This program has proven to work well with chronic patients. Further data, not analyzed as yet, also indicates the efficacy of this treatment in acute cases.

Familial approach to the treatment of childhood obesity: conceptual mode

This model for the management of childhood obesity uses a family-based approach. Change is delivered through the parents (instead of the obese child) emphasizing a healthy lifestyle and not weight reduction as in previously published, family-based management of childhood obesity. This intervention integrates behavioral, social learning, and family system approaches. The proposed approach includes changes in parental cognition, emphasizing "parenthood presence"; parents serve both as a source of authority and a role model for the obese child, providing a family environment that fosters healthy practices related to weight control issues and de-emphasizing personal responsibility for control of health behavior.

Impact of treatment for childhood obesity on parental risk factors for cardiovascular disease

BACKGROUND

Family-based approaches using the parents as agents of change to treat childhood obesity are superior to programs targeting only children in achieving weight reduction and have a lower dropout rate.

OBJECTIVE

The aim of this study was to compare the impact of two behavioral approaches (parents only vs children only) for the treatment of childhood obesity on parental weight, eating, and activity habits as well as cardiovascular risk factors.

DESIGN

A randomized 1-year clinical intervention study was performed.

METHODS

Sixty obese children (>/=20% over ideal weight for age, height, and sex), ages 6-11 years, were randomly allocated to the experimental (parents as sole agents of change) or conventional groups (children as sole agents of change). Fourteen (1-h-long) support/educational sessions were conducted by a clinical dietitian for the parents in the experimental group and 30 sessions for children in the conventional group. Anthropometric and biochemical measurements were determined at the start and end of the program.

RESULTS

The experimental approach, when compared to the conventional intervention, was found to be superior in the reduction of fathers overweight (P < 0.05). The former approach resulted also in improved profile of risk factors for cardiovascular disease in both parents. These changes could be ascribed to a greater improvement in eating and activity behaviors observed in parents belonging to the experimental intervention group who participated in a family-based intervention to treat their children's obesity.

CONCLUSIONS

Treatment of childhood obesity targeting the parents as the sole agent of change, which is more effective for the treatment of childhood obesity when compared to a children-oriented program, may in addition award parents with the benefit of changing their own eating and activity patterns, thus making this program ideal for treatment of obesity in children and their overweight parents.

Role of behaviour modification in the treatment of childhood obesity with the parents as the exclusive agents of change

OBJECTIVE

This study examined the reduction in overweight and changes in eating-related behaviours in obese children treated with a family-based approach, in which the parents were the exclusive agents of change. Results were compared to the conventional approach in which children are responsible for their own weight loss.

DESIGN

A one-year longitudinal prospective design was used. Participants were randomly allocated for the experimental (parents as the agents of change) or the conventional (children as the agents of change) intervention.

METHODS

Sixty obese children (20% over ideal weight for age, height and gender) aged 6-11 y (mean+/-s.d. 9.2+/-1.0 y) were included in the study. Anthropometric measurements and biochemical tests were performed on the children and their parents before and after the programme, and both parents completed a sociodemographic and a family eating and activity habits questionnaire. Hour-long support/educational sessions were conducted by a clinical dietitian-14 sessions for the parents in the experimental intervention and 30 for the children in the conventional intervention. Individual sessions were held for members of both groups, when necessary.

RESULTS

Significant differences were found between the two groups in the reduction of exposure to food stimuli and changes in eating habits (eating while standing, watching TV, reading or doing homework, eating following stress and eating between meals). Mean weight reduction (by percentile) was significantly greater in the experimental intervention group (parent-only treatment) in comparison to the conventional intervention group (child-only treatment).

CONCLUSIONS

Treatment of childhood obesity with the parents as the exclusive agents of change, induces more behavioural changes as well as greater weight loss, than the conventional approach.

Reliability and validity of the Family Eating and Activity Habits Questionnaire

OBJECTIVE

The purpose of this work was to develop and test an instrument that will identify the factors that facilitate childhood obesity and monitor the environmental changes and family behavior modifications associated with weight loss.

DESIGN AND METHODS

The relevant factors that affect obesity and weight loss in children were divided into four scales: activity level, stimulus exposure, eating related to hunger, and eating style. We designed a questionnaire to be completed by the parents of the obese child aged 6-11 years. Scores accumulated were calculated separately for each member of the family. Higher numerical scores reflected less appropriate eating patterns. The questionnaire reliability (test-retest), internal consistency and ability to discriminate obese vs normal-weight children's behaviors was tested using a pilot population of 40 mothers not enrolled in a formal weight loss program. The questionnaire reliability (parents' report and spouse report) and predictive validity was tested using a selective population: 60 parents of obese children enrolled in a clinical intervention intended to treat childhood obesity with an environmental approach vs a dietary approach.

RESULTS

The content validity of the questionnaire was evaluated by a team of ten experts. Cronbach's alpha was calculated to test internal consistency. Mean r was 0.83. Pearson's correlation coefficients were computed between test and retest scores for individual items and for the total score, and ranged from 0.78 to 0.90 (median 0.84) (P < 0.01 for all). Total score test-retest r was 0.85 (P < 0.01). The total family score was also higher in the families with an obese child compared to families with a normal-weight child, P < 0.01. No significant differences were noted between parent report and spouse report scores. The construct validity of the questionnaire was also supported by its high sensitivity to weight loss treatment. Weight loss in the child correlated highly with improvement in questionnaire score.

CONCLUSIONS

The Family Activity and Eating Habits Questionnaire is reliable and internally consistent, and it is useful as an optional tool for planning an intervention program for childhood obesity.

Parents as the exclusive agents of change in the treatment of childhood obesity

BACKGROUND

Excessive weight in childhood is a serious public health concern because of its costly health consequences and its increasing prevalence.

OBJECTIVE

Our objective was to compare the efficacy of a family-based approach for the treatment of childhood obesity, in which the parents served as the exclusive agents of change, with that of the conventional approach, in which the children served as the agents of change.

DESIGN

This study had a randomized, longitudinal prospective design and lasted 1 y. Sixty obese children aged 6-11 y were randomly allocated to the experimental (parents as agents of change) or control (children as agents of change) group. Anthropometric and biochemical measurements were determined at the start and end of the study. A sociodemographic questionnaire and a family eating and activity habits questionnaire were completed by both parents. Hour-long support and educational sessions were conducted by a clinical dietitian: 14 sessions for the parents in the experimental group and 30 sessions for the children in the control group.

RESULTS

The dropout rate was nine times greater in the control group (n = 9) than in the experimental group (n = 1). Mean percentile weight reduction was significantly (P < 0.03) higher in children in the experimental group (14.6%) than in the control group (8.1%).

CONCLUSIONS

Treatment of childhood obesity with parents as the exclusive agents of change was superior to the conventional approach, as indicated by the dropout rate and the percentage weight loss of the children during the 1-y intervention.

[Angina pectoris as a symptom of gastric volvulus]

Angina pectoris is a common complaint in any emergency service, but it rarely is of extracardiac origin. A rare case of gastric volvulus which presented a recurrent angina pectoris in a 47-year-old man is reported. Repeated episodes of angina pectoris in a patient with a negative cardiac investigation should alert the physician to the possibility of extracardiac pathology.

Synergism between infarct-borne left ventricular dysfunction and cardiomegaly in increasing the risk of coronary bypass surgery

The effect of cardiomegaly on operative and late mortality in patients with left ventricular dysfunction undergoing coronary bypass operation was investigated. The study group consisted of 178 patients whose left ventricular ejection fraction was below 45% and who were operated on from 1978 through 1985. Forty-five patients (group A) had severe left ventricular dysfunction (ejection fraction < 30%) and 133 (group B) had moderate dysfunction (30% > ejection fraction > 45%). Twenty-four of group A (53%) and 54 of group B (41%) patients had cardiomegaly (cardiothoracic ratio on chest x-ray films > 0.5). There were 10 (6%) hospital deaths, four in group A (9%) and six in group B (4.5%). All four deaths in group A and the six deaths in group B were patients who had cardiomegaly. Regardless of the severity of the left ventricular dysfunction, there was no operative death among patients with normal heart size (p < 0.001). Age over 65, bypass time longer than 2 hours, and incomplete revascularization emerged as risk factors. Follow-up ranged from 5 to 13 years (mean 7.8 years). Overall 5-year actuarial survival, including hospital mortality, was 80% +/- 3%. Reduced 5-year survival was observed in patients with cardiomegaly (67% +/- 5% versus 91% +/- 3%, p < 0.05). Five- and 10-year survival of patients from group A with cardiomegaly was 53% +/- 7% and 18% +/- 13%, respectively.

Solid swallowing versus water swallowing: manometric study of dysphagia

The aim of the study was to investigate whether a soft solid bolus can induce abnormal manometric patterns in patients with dysphagia and normal standard manometry. The study group comprised 12 normal volunteers and 22 patients with dysphagia. Manometry was performed using 10 wet swallows followed by 10 swallows of marshmallow. The results show: (1) in normal subjects the mean contraction amplitude is significantly greater (P less than 0.035) and the velocity of propagation significantly slower (P less than 0.003) for soft solid swallows compared with wet swallows; (2) in normal subjects there are fewer abnormal contractions after soft solid swallows than after wet swallows; (3) in 15 patients, soft solid swallows induced non-peristaltic contractions and/or contractions of extreme amplitude and/or duration that were not observed after wet swallows; (4) in patients, the probability of inducing abnormal contractions after soft solid swallows is significantly greater than after wet swallows (P less than 0.0001). We conclude that soft solid swallowing is useful in the study of patients with dysphagia.

Penetrating thoracic wounds caused by plastic bullets

Thoracic penetrating injuries caused by a new plastic bullet were studied to determine the nature of the wounds and the appropriate management. Twenty-six casualties from the Israeli-Palestinian conflict (Intifada) were included. The organs most commonly involved were lung (n = 21), bony chest wall (n = 9), heart (n = 3), and diaphragm. Bleeding was at least moderate in 20 patients, amounting in all patients to an average of 975 ml. Thoracotomy was required in 11 patients (42%) mainly because of cardiac injury (n = 3) and aortic or other arterial bleeding (n = 3). Simple oversewing of severed organs (n = 8) or ligation of bleeding vessels (n = 3) was satisfactory. Two patients died (7.7% mortality); one after major liver resection; the other was dead on arrival. We conclude that plastic bullets have a linear course unless displaced by the bony chest wall, when they tend to fragment and cause simple fractures. Fired from a presumed range of at least 70 m, plastic bullets behave like low-velocity missiles, and tissue destruction is minimal. Management should be similar to that of civilian thoracic penetrating trauma.

Plastic bullet arterial embolization following gunshot injury to the heart. Case report and review of the literature

A plastic bullet penetrating the heart through the right ventricle embolized to the right profunda. Suture of the heart and extraction of the bullet resulted in uneventful recovery. The literature revealed 21 instances of embolization following proven heart penetration, in two cases through the right ventricle.

Transfusion of fresh whole blood stored (4 degrees C) for short period fails to improve platelet aggregation on extracellular matrix and clinical hemostasis after cardiopulmonary bypass

It has recently been shown that the hemostatic effect of 1 unit of fresh whole blood is equivalent to the effect of 8 to 10 platelet units. This study was designed to evaluate the effect of short periods of cold (4 degrees C) storage on the hemostatic effect of fresh whole blood transfusion in 36 patients immediately after cardiopulmonary bypass. Twelve patients (group A) received unrefrigerated fresh whole blood, 12 (group B) received fresh whole blood after 5 hours' storage at 4 degrees C, and 12 (group C) after 24 hours' storage at 4 degrees C. For evaluation of platelet function, a method with an extracellular matrix and an electron microscope was used. The platelet function was graded from 1 to 4, with grade 4 being normal aggregation. Postoperatively, group A patients bled less than groups B and C (267 +/- 42 versus 397 +/- 72 and 601 +/- 172 ml/24 hr, respectively, p less than 0.001) and therefore received fewer blood units (1.4 +/- 0.5 versus 2 +/- 0.9 and 3 +/- 1.4, respectively, p less than 0.01). Five patients of group A (42%) reached grade A aggregation after transfusion of unstored fresh whole blood, compared with two (17%) of group B and none (0%) of group C (p less than 0.01). Posttransfusion platelet count and mean platelet volume were not significantly different in the three groups. We conclude that storage at 4 degrees C, even for a short period of 5 hours, diminishes the hemostatic effect of fresh whole blood by decreasing platelet aggregability.

The effect of transfusion of fresh whole blood versus platelet concentrates after cardiac operations. A scanning electron microscope study of platelet aggregation on extracellular matrix

To evaluate the effect of fresh whole blood transfusion versus platelet concentrates transfusion on platelet aggregation after cardiac operations, 24 patients were randomized to receive either one unit of fresh whole blood (12 patients) or 10 platelet units (12 patients) after cardiopulmonary bypass. Platelet aggregation on extracellular matrix, platelet count, and mean platelet volume were studied preoperatively, at termination of cardiopulmonary bypass, after protamine administration, and after the transfusion of fresh whole blood or after transfusion of each two platelet units. Extracellular matrix produced by cultured bovine corneal cells closely resembles the vascular subendothelial basal lamina, and is an ideal in vitro model in the study of platelet interaction with the subendothelium. Platelet aggregation on extracellular matrix, studied by a scanning electron microscope, was graded from 1 to 4, wherein grade 1 represents nonactivated platelets and grade 4 a mature platelet aggregate. With this grading system, the two groups were similar in preoperative values (3.3 +/- 0.9 versus 3.7 +/- 0.4) and values after cardiopulmonary bypass (1.5 +/- 1.0 in both groups). One unit of fresh whole blood restored platelet aggregation on extracellular matrix to preoperative status (3.0 +/- 1.0), whereas eight platelet units were needed for the same result (3.2 +/- 0.8). One unit of fresh whole blood increased platelet count in a manner similar to that achieved by six platelet units and increased mean platelet volume to a level higher than that achieved by 10 platelet units. These results suggest that the effect of one unit of fresh whole blood on platelet aggregation after cardiopulmonary bypass is at least equal, if not superior, to the effect of 8 to 10 platelet units.

Studies of manometric abnormalities of the rectoanal region during defecation in constipated and soiling children: modification through biofeedback therapy

Anorectal manometry was performed on 12 normal children and 18 patients suffering from constipation and soiling. In both groups, the results of the rectoanal inhibitory reflex and the squeezing anal pressure were similar. The pressure recording in all the normal children showed that the anal canal relaxed during defecation. Fourteen (78%) constipated children closed the anal canal while straining by contracting the anal sphincter. This paradoxical contraction appears to be the cause of chronic constipation. Twelve children with paradoxical anal closure were treated by biofeedback therapy. The results show that all these children were successfully conditioned to relax their anal sphincter during defecation. This therapy improved their bowel habits and relieved them from constipation and soiling. It is proposed that the paradoxical anal closure itself is the result of a self-conditioning process. In this process, the patient learns to paradoxically contract the external anal sphincter in response to the urge and the act of defecation. Biofeedback therapy seems to be the appropriate treatment in such cases.

Coronary artery bypass surgery in a cadaver kidney transplant recipient

A review of the literature revealed that reports on coronary bypass operations in post renal transplant patients are rare. Here a case of successful coronary by-pass operation in a renal transplant patient is reported.