Localization of motoneurons innervating the stylopharyngeus muscle in the cat

Recent investigations of the nucleus ambiguus (NA) have attempted to identify motoneurons associated with muscles of the larynx and pharynx. However, relatively little attention has been directed to the stylopharyngeus muscle, which is important in elevation of the pharynx in swallowing and speech. The present study was designed to identify the specific location of stylopharyngeus motoneurons within the brainstem. Horseradish peroxidase or fluorescent dye was injected into the stylopharyngeus muscle of 12 cats. Retrogradely labeled cells were located ipsilateral in the rostral NA and retrofacial nucleus. This is the first report to definitively localize stylopharyngeus motoneurons.     

Identification of four novel melanocortin 1 receptor (MC1R) gene variants in a Mediterranean population

The melanocortin 1 receptor (MC1R) gene is a major determinant of human pigmentation and specific allelic variants have been associated with red hair and sun sensitive skin types as well as increased skin cancer risk in Caucasian individuals. We screened for allelic variants the entire MC1R coding region of 100 unrelated individuals sampled from an Italian population who has darker pigmentary traits than populations analyzed to date. Twenty MC1R variants were identified, eighteen located at non-synonymous sites and two at synonymous sites. We report four novel MC1R allelic variants: C35Y (g.104G>A), V38M (g.112G>A), L44V (g.130C>G) and I120T (g.359T>C).     

Role of nitric oxide in the biology, physiology and pathophysiology of reproduction

Following its benchmark discovery, nitric oxide (NO) is nowknown to play important functional roles in a variety of physiologicalsystems. Within the vasculature, NO induces vasodilation, inhibitsplatelet aggregation, prevents neutrophil/platelet adhesionto endothelial cells, inhibits smooth muscle cell proliferationand migration, regulates programmed cell death (apoptosis) andmaintains endothelial cell barrier function. NO generated byneurons acts as a neurotransmitter, whereas NO generated bymacrophages in response to invading microbes acts as an antimicrobialagent. Because neurons, blood vessels and cells of the immunesystem are integral parts of the reproductive organs, and inview of the important functional role that NO plays in thosesystems, it is likely that NO is an important regulator of thebiology and physiology of the reproductive system. Indeed, inthe past 10 years, NO has established itself as a polyvalentmolecule which plays a decisive role in regulating multiplefunctions within the female as well as the male reproductivesystem. This review provides an overview of the role of NO invarious reproductive organs under physiological and pathologicalconditions.     

Isolation of the right subclavian artery with subclavian steal in a child with Klippel-Feil anomaly: an example of the subclavian artery supply disruption sequence

We studied a patient with Klippel-Feil anomaly and subclavian steal due to isolation of the right subclavian artery. Other anomalies included hypoplasia of the right clavicle and right vertebral artery, low bifurcation of the left common carotid artery and left choanal atresia. The patient was mentally retarded with corticospinal, cerebellar, and brain stem signs. The entire brain and cervical spinal cord were small; there was no central nervous system malformation, hydrocephalus, or bony impingement on neural structures. Embryologic vascular disorders have been found to be responsible for various congenital systemic and neurologic anomalies such as intestinal atresia and hydranencephaly. Subclavian artery supply disruption sequence has been hypothesized to result in Klippel-Feil, Poland, and M?bius anomalies. In this case the vertebral and facial abnormalities may well be related to anomalous subclavian and carotid supply. An embryonic vascular "steal" has been thought to cause the sirenomelia anomaly. We postulate that the subclavian steal, during the embryonic period, may have been responsible for the small size of this patient's cerebral hemispheres, brain stem, cerebellum, and cervical spinal cord.     

X-ray determination of crystalline hydroxyapatite to amorphous calcium-phosphate ratio in plasma sprayed coatings

A method to measure the amorphous calcium phosphate (ACP) content of plasma sprayed hydroxyapatite (HA) coatings is presented. The areas of the crystalline peaks and the broad amorphous "hump" in an X-ray diffraction scan of a mixture of crystalline and amorphous HA can be fitted using conventional nonlinear least-squares methods. The weight fraction of the amorphous component in a mixture of unknown proportions is obtained from the measured hump fraction using a linear expression requiring a single calibration constant. This calibration constant may be determined by applying the same sample preparation, X-ray measurement, and least-squares fitting methods to a single standard of known (weighed) proportions as used to measure the unknown(s). Application of this method to a set of 12 samples yields an "index of crystallinity" for plasma sprayed HA coatings with an estimated standard deviation of 1 wt % ACP across the entire compositional range.     

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Strain-specific development of the mossy fiber system in organotypic cultures of the mouse hippocampus

The postnatal development of the hippocampus of the inbred mice strains BALB/c, C57BL/6, and DBA/2 was studied in organotypic explant cultures using the roller-tube technique. In vivo, mice exhibit strain-specific mossy fiber distribution patterns. As a main result we found, that after cultivation of 3-4 weeks, similar strain-specific patterns became apparent in vitro, as visualized by a modified Timm staining. From this experiment we can conclude that a postnatal extrinsic influence cannot be the cause of the strain-specific hippocampal features.     

Nicotinamide reduces high secretion of IFN-gamma in high-risk relatives even though it does not prevent type 1 diabetes.

Type 1 diabetes (T1D) is an autoimmune disease suggested to be of a T helper (Th)1-like origin. This study aimed to investigate the Th1-like and Th2-like profile in high-risk individuals during the prediabetic phase and the immunologic effect of treatment with nicotinamide. High-risk first-degree relatives of T1D patients participating in the European Nicotinamide Diabetes Intervention Trial (ENDIT) were treated with either nicotinamide or placebo. Peripheral blood mononuclear cells (PBMC) were obtained during the prediabetic phase and close to the onset of manifest T1D and from nondiabetic high-risk individuals. Using the sensitive enzyme-linked immunospot (ELISPOT) technique to distinguish Th1-like from Th2-like lymphocytes, secretion of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) was analyzed from PBMCs spontaneously and after in vitro stimulation with the diabetes-associated autoantigens, glutamic acid decarboxylase 65 (GAD65, protein and peptide, aa 247-279), recombinant tyrosine phosphatase (IA-2), and heat shock protein (HSP, aa 437-460). High-risk individuals showed high spontaneous as well as autoantigen-induced IFN-gamma secretion. Secretion of IFN-gamma and the IFN-gamma/IL-4 ratio, induced by autoantigens, decreased in individuals developing T1D (p < 0.05), whereas nondiabetic individuals showed an increased IL-4 response (p < 0.05). Thus, a Th1-dominated cytokine profile observed in high-risk individuals inclined toward a diagnosis of diabetes. Nicotinamide caused decreased spontaneous (p = 0.05) and in vitro autoantigen-induced IFN-gamma secretion (p < 0.05) and may play a role in immune regulation, even though it has not been shown to prevent T1D.