HP18THE GOOD,THE FAT AND THE UGLY: METABOLIC HORMONES AND THE HEART

Obesity related cardiovascular disease has assumed epidemic proportions and it is important that we properly understand how hormones of metabolism influence cardiac function. Over the last 15 years a multitude of factors have been discovered that appear to play significant roles in energy balance and metabolism, markedly changing our view of fat and GI cells and their dynamic control and regulation of metabolism. This presentation will focus on how three recently discovered hormones Ghrelin, Leptin and Resistin may directly influence cardiac function. Ghrelin is predominately produced and secreted from the X/A cells of the stomach and studies suggest it can act as a cardioprotective agent. However, Ghrelin also acts to constrict the coronary arteries, which places potential limitations upon its therapeutic use. Leptin is produced by adipose tissue in proportion to fat deposition and appears to drive satiety signals in the body. In contrast, Leptin appears to antagonise cardiac function and it may drive the development of hypertension by impairing renal pressure natriuresis and down regulating endothelium derived vasorelaxant factors. The third factor, Resistin, was originally described from rat adipose tissue and was shown to impair insulin action and glucose control. In humans however, Resistin is primarily produced in inflammatory cells such as monocytes and macrophages. Resistin worsens the recovery of the heart from a period of experimental ischemia and promotes the release of inflammatory agents such as tumour necrosis factor‐alpha. Such actions may be partially responsible for the observed insulin resistance after cardiac surgery.     

Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand

Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml ^-1), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml ^-1) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-² week^-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis.     

Iotrol versus metrizamide in lumbar myelography: a double-blind study

In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population.     

Ileal pouch-anal anastomosis for chronic ulcerative colitis. Long-term results.

The aim of this study was to determine the long-term outcome among 390 patients with ulcerative colitis who underwent ileal J pouch-anal anastomosis and whether patient or operative factors influenced results. The combined operative morbidity rate for the pouch-anal anastomosis and the subsequent closure of the temporary ileostomy was 29% (bowel obstruction, 22%; pelvic sepsis, 5%), with one death due to pulmonary embolus. The probability of a successful outcome at 5 years was 94%. Of the 24 patients who failed (6% of total), 18 did so within 1 year (4%), three during year 2 (1%), three during year 3 (1%), and none thereafter. Stool frequency (7 stools/24 h), the occurrence of pouchitis (14%), and satisfactory daytime continence (94% of patients) remained stable over 4 years after operation, whereas nocturnal fecal spotting decreased (51% of patients to 20%). Women had more spotting than men, whereas patients over 50 years old had more stools per day than those 50 years or younger. In conclusion, ileal pouch-anal anastomosis achieved a reasonable stool frequency and satisfactory continence in patients with ulcerative colitis over the long-term. These results support the ileal pouch-anal anastomosis as a safe, satisfactory alternative to permanent ileostomy.     

臂丛神经根性损伤膈神经移位术对青壮年患者早期呼吸功能的影响

目的研究臂丛神经损伤膈神经移位术对青壮年患者早期呼吸功能的影响.方法对16例接受膈神经移位治疗的患者,在术前、术后（10 d）进行肺功能指标的比较,同时定期进行门诊随访,观察呼吸系统自觉症状程度.结果13例术后出现了不同程度的供氧不足症状,16例全部出现一侧膈肌抬高,术后第10天肺活量（VC）、肺活量预计值百分数（VC%）分别比术前减少37.98%和26.88%,两者差异有统计学意义（tvc=11.532、tvc%=0,P＜0.01）.其它项目如残气量（RV）较术前轻度下降,肺总量（TLC）下降值达到术前肺总量的36.49%,残气量/肺总量比值（RV/TLC%）较术前上升了4.75%,上述各指标的差值均有统计学意义.1 s用力呼气量/用力肺活量比值（FEV1/FVC）和术前比基本无改变,但其差值有统计学意义.膈神经移位右侧（10例）与左侧（6例）术前、术后肺活量比较差异有统计学意义.术后随访8个月～2年,所有患者均无明显呼吸困难和胸闷等症状.结论膈神经移位术后对青壮年患者肺容量有较大的丧失,肺通气功能减弱和小气道阻力增加,但其丧失程度在机体自身代偿耐受范围内,不会导致急剧发生的严重呼吸功能障碍.建议对右侧臂丛神经根性损伤的患者,术前进行严格的肺、心功能检查,避免发生较为严重的并发症.     

Congenital thrombophilia among patients with venous thromboembolism.

During a 3-year period we studied 393 adult patients (382 of whom were unrelated) with a history of acute venous thromboembolism. A congenital deficiency state known to predispose to thrombosis was found in 27.2%. Of these, most were due to deficiencies of protein C (9.2%), protein S (7.6%), antithrombin III (5%) or to increased plasma PAI-1 concentration (3.1%) which, in the absence of any known factor that predisposes towards thrombosis, results in a diminished fibrinolytic activity. There was a characteristic pattern between the age of onset (mean 34 years) of thrombosis and individual protein deficiency. Thrombosis appeared spontaneously in 73% of cases with recurrence in 80%. In contrast, in the remaining unrelated patients, 138 (35.1%) in whom venous thromboembolism was secondary and occurred at a mean age of 43 years, and in the other 140 (35.6%) who suffered thromboembolism spontaneously at a later age (mean age 55), there was no permanent protein deficiency state or alteration in fibrinolytic activity and thrombosis recurrence was lower (53.6% and 20.7% respectively). Of the 393 patients, deep vein thrombosis was the most common manifestation; however, in congenital thrombophilia, thrombosis of visceral vessels and Raynaud's syndrome (6%) were also detected.