Neuropeptide Y: Immunocytochemical localization to and effect upon feline pial arteries and veins in vitro and in situ

Plexuses of nerve fibres containing neuropeptide Y (NPY)-like immunoreactivity invest pial arteries belonging to the circle of Willis, pial arterioles, occasionally penetrating arterioles and large veins. A more sparse supply of NPY-like fibres are observed around pial veins and venules. The NPY-immunoreactive fibres are located within the adventitia or at the adventitia-media border. Only occasional fibres are present in cerebral vessels of animals in which the superior cervical ganglion has been removed one week previously. Administration of NPY resulted in strong, concentration-dependent contractions of isolated feline middle cerebral arteries whereas administration of avian pancreatic polypeptide (APP) elicited weak contractions. In chloraloseanaesthetized cats, perivascular microapplication of NPY in situ resulted in marked concentration-dependent contractions of cerebral pial arterioles (34.7±6.6%; maximum decrease in calibre with NPY. Perivascular administration of NPY resulted in the constriction of pial veins but the magnitude of the venous calibre reductions was smaller than the response of arterioles at each reductions was smaller than the response of arterioles at each concentration examined. APP did not elicit contraction of pial arterioles or veins during in situ conditions. The pharmacological and immunocytochemical results strongly indicate the existence of a novel perivascular neuronal system containing NPY, which mediates contraction of cerebral blood vessels and NPY is colocalized with NA in sympathetic nerves.     

CASE REPORT: Primary hepatic lymphoma associated with chronic liver disease

We report on a case of primary hepatic lymphoma that developed in a patient with chronic hepatitis C. Given that Japan is an area endemic for both hepatitis B and C viruses, we reviewed 51 Japanese cases of primary hepatic lymphoma, addressing the question as to whether the Japanese cases have unique characteristics and whether there is a causal relationship to the presence of chronic liver disease. Primary hepatic lymphoma most commonly affected middle-aged males. Presenting symptoms and physical findings were non-specific. Aminotransferases tended to stay in the low range compared with marked increases in lactate dehydrogenase. Sixteen patients (31%) had chronic liver disease, eight had liver cirrhosis and eight had chronic hepatitis, suggesting that there is a possible aetiological link between chronic liver disease and primary hepatic lymphoma.     

Vasopressin plus oxygen vs vasopressin alone in cirrhotic patients with portal-hypertensive gastropathy: Effects on gastric mucosal haemodynamics and oxygenation

The effects of vasopressin plus oxygen and vasopressin alone on gastric mucosal perfusion and oxygenation were studied using reflectance spectrophotometry and laser Doppler velocimetry in 23 cirrhotic patients with portal-hypertensive gastropathy. The measurements were performed under basal conditions and after double-blinded administration of placebo (n= 7), vasopressin (0.3 U/min; n= 8) or vasopressin (0.3 U/min) plus nasal oxygen (4 L/min; n= 8). No significant effects on gastric mucosal haemodynamics and oxygenation were observed after placebo. In contrast, vasopressin and vasopressin plus oxygen induced a similar reduction in haemoglobin content (-26 ± 2 and -21 ± 4%, respectively P < 0.01) and laser Doppler signal (-23 ± 2 and -22 ± 2%, respectively, P < 0.01). Although each treatment induced a significant reduction in oxygen saturation (-21 ± 2 and -7 ± 1%, respectively P < 0.01), the effect was less pronounced in patients receiving the combination than in those receiving vasopressin alone (P < 0.01). These data suggest that vasopressin and vasopressin plus oxygen reduce gastric mucosal hyperaemia and that the oxygen supplement partially protects against gastric mucosal hypoxia during vasopressin infusion in cirrhotic patients with portal-hypertensive gastropathy.