Safer, more expensive iodinated contrast agents: how do we decide?

The advantages of the new, safer, but more expensive iodinated contrast agents are discussed, and opinions on which patient groups should receive the agents are presented.     

抗胆碱药3-(2-苯基-2-环戊基-2-羟基-乙氧基)奎宁环烷的立体化学和构效关系

研究了强效抗胆碱药dl-3-(2-苯基-2-环戊基-2-羟基-乙氧基)-奎宁环烷的四个光学异构体的两种不对称合成方法,用HPLC检测了异构体含量,讨论了构效关系。     

Pulmonary artery catheterization: a modified technique

A modified technique for catheterization of the pulmonary artery was developed. It involves the passage of a tapered, movable-core, J-tipped guide wire across the right ventricle into the pulmonary artery followed by the advancement of a straightened Grollman pigtail catheter. The technique was successful in 34 of 34 pulmonary artery catheterizations. The method avoids prolonged catheter manipulation within the right ventricle. In addition, since the catheter does not cross the tricuspid valve until the guide wire has been advanced, the occasional complication of the pigtail "hooking" on a tricuspid valve leaflet or chordae tendineae during catheter withdrawal and manipulation is prevented.     

Effect of omega-3 fatty acids on rectal mucosal cell proliferation in subjects at risk for colon cancer.

The effects of 12 weeks of omega-3 fatty acid supplementation on rectal mucosal proliferation were assessed with [3H]thymidine autoradiography in a double-blind, placebo-controlled study of 20 patients with sporadic adenomatous colorectal polyps. In the group of 10 that received fish oil containing eicosapentaenoic acid (4.1 g/day) and docosahexaenoic acid (3.6 g/day), the mean percentage of replicative "S"-phase cells in the upper part of colonic crypts (considered a reliable marker of colon cancer risk) significantly dropped from the baseline level after only 2 weeks of treatment and remained lower throughout the study period; no change in upper-crypt labeling was observed in the 10 placebo patients. Rectal mucosal eicosapentaenoic acid content increased in fish oil patients, whereas arachidonic acid levels decreased. The fish oil-induced kinetic changes represent contraction of the proliferative compartment to the levels of a low-risk population and may be related to omega-3 fatty acid effects on the arachidonic prostaglandin pathway. In this short-term trial, fish oil appeared to exert a rapid effect that may protect high-risk subjects from colon cancer.     

乳腺管状小叶癌

乳腺管状小叶癌（Tubulolobular carcinoma，TLC）最初是被作为小叶癌的管状变型。作者总结了27例TLC的组织学、免疫表型和临床特征，并与纯小管癌和经典型小叶癌进行了比较。此组患者年龄43-79岁（中位年龄60岁）。1例双侧乳腺受累，5例病变为多灶性。肿瘤直径0．5-2．5cm，色灰褐，质硬。组织学观察：TLC的肿瘤细胞形成管状和条索状两种结构模式并相互混杂，且两者比例相当（统称为管状小叶模式）。     

Proceedings of the Symposium ‘Angiotensin AT1 Receptors: From Molecular Physiology to Therapeutics’: PHYSIOLOGICAL ACTIONS OF ANGIOTENSIN II MEDIATED BY AT1 AND AT2 RECEPTORS IN THE BRAIN

• 1 Autoradiographic binding studies have shown that the AT₁ receptor is the predominant angiotensin II (AngII) receptor subtype in the central nervous system (CNS). Major sites of AT₁ receptors are the lamina terminalis, hypothalamic paraventricular nucleus, the lateral parabrachial nucleus, rostral and caudal ventrolateral medulla, nucleus of the solitary tract and the intermediolateral cell column of the thoraco-lumbar spinal cord.
• 2 While there are differences between species, AT₂ receptors are found mainly in the cerebellum, inferior olive and locus coeruleus of the rat.
• 3 Circulating AngII acts on AT₁ receptors in the subfornical organ and organum vasculosum of the lamina terminalis (OVLT) to stimulate neurons that may have a role in initiating water drinking.
• 4 Centrally administered AngII may act on AT₁ receptors in the median preoptic nucleus and elsewhere to induce drinking, sodium appetite, a sympathetic vasoconstrictor response and vasopressin secretion.
• 5 Recent evidence shows that centrally administered AT₁ antagonists inhibit dipsogenic, natriuretic, pressor and vasopressin secretory responses to intracerebroventricular infusion of hypertonic saline. This suggests that an angiotensinergic neural pathway has a role in osmoregulatory responses.
• 6 Central angiotensinergic pathways which include neural inputs to the rostral ventrolateral medulla may use AT₁ receptors and play a role in the function of sympathetic pathways maintaining arterial pressure.

     

Treatment of hypogonadal adolescent boys with long acting subcutaneous testosterone pellets

AIMS: Long acting subcutaneous testosterone pellets are of proved efficacy for the treatment of hypogonadal men, but have not been reported as a treatment modality in adolescent boys. Pharmacodynamic studies of subcutaneous testosterone release have shown prolonged normalisation of testosterone levels for at least four months. Administration of a long acting, safe, effective, and convenient form of treatment is desirable when life-long treatment is indicated. PATIENTS AND METHODS: Eighteen boys (aged 13.9-17.5 years at the start of treatment)-seven with primary hypogonadism, nine with secondary hypogonadism, and two boys being treated with testosterone for tall stature--were given testosterone pellets (8-10 mg/kg) every six months for 18 months. Height, weight, pubertal status, and psychosocial parameters were assessed and follicle stimulating hormone, luteinising hormone, testosterone, prolactin, and lipids were measured at 0, 1, 3, 6, 12, and 18 months. Bone age was measured at 0 and 12 months. RESULTS: In all boys growth velocity continued appropriately for bone age. Puberty continued to progress in all boys and in two boys the amount of virilisation exceeded that seen with previous treatment with intramuscular testosterone. After testosterone administration, follicle stimulating hormone and luteinising hormone suppressed incompletely in the boys with primary hypogonadism. Serum testosterone ranged from 4.3 to 26.7 nmol/l at three months to less than 10 nmol/l at six months after implantation. Prolactin and lipid levels were normal throughout the study. By report, there was an improvement in mood and emotional wellbeing. No pellet extrusions occurred in a total of 156 pellet insertions. CONCLUSIONS: All boys preferred this mode of testosterone administration to intramuscular injections. Long acting subcutaneous testosterone pellets are safe, efficacious, well tolerated, and convenient, and result in normal physical growth and improved psychological outlook in adolescent hypogonadal boys.