Why do long-distance runners not have more bone? A vital biomechanical explanation and an estrogen effect

Inanimate structures cannot detect and repair their fatigue damage or microdamage, so to minimize it they need more structural material and strength. Living bone handles this matter differently. Bone modeling drifts adapt bone architecture and strength to the loads on bones in ways that tend to keep strains from exceeding a “modeling threshold” range. Strains (or equivalent features) above that threshold switch mechanically controlled modeling ON. Where strains stay below that threshold, this modeling goes OFF. Repeatedly loading-deloading a bone causes microdamage in it, and basic multicellular unit (BMU)-based bone remodeling normally repairs it. Where strains stay below an operational “microdamage threshold,” remodeling can repair whatever microdamage happens for as long as it happens. Strains above that threshold can cause too much microdamage to repair completely and lead to fatigue fractures of trabeculae or whole bones. The modeling threshold normally lies comforably below the microdamage threshold. Since modeling normally adjusts bone architecture to keep strains from exceeding the modeling threshold, this keeps strains below the microdamage threshold, too, and voluntary activities do not cause more microdamage than remodeling can repair. Therefore, long-distance runners do not need more bone mass and strength than nonrunners of comparable age, sex, and body size.     

从脾论治磺脲类降糖药继发性失效

对 64例 2型糖尿病继发磺脲类降糖药失效患者 ,在继续口服磺脲类药的基础上加用健脾中药 ,结果显效 1 5例 ,有效 3 6例 ,无效 1 3例 ,总有效率 85 .2 4% ;治疗前后血糖明显下降 ,有显著性差异 ( P<0 .0 0 1 )     

玻璃体切除术治疗晶体脱位继发性青光眼

目的 :探讨玻璃体切除术治疗晶体脱位继发青光眼的疗效。方法 :晶体脱位继发青光眼 2 9眼 ,行前部玻璃体切除术联合晶体摘除 14眼 ;睫状体扁平部三孔闭合式玻璃体切除术联合晶体摘除 15眼。一期植入人工晶体 12眼。结果 :随访 2 2眼 1～ 12月 ,平均 8.5月。 18眼眼压 <2 1mmHg ,2眼局部滴抗青光眼眼水 ,眼压为 2 4mmHg ,2眼口服降眼压药物 ,眼压为 2 4 .0 0± 3.2 5mmHg。视力提高 16眼 ,无变化 6眼。结论 :玻璃体切除术治疗晶体脱位继发青光眼安全有效     

Epilepsy after operative treatment of ruptured cerebral aneurysms

Summary A retrospective analysis of 183 consecutive patients operated on for ruptured cerebral aneurysms and surviving at least one year revealed appearance of postoperative epilepsy in 14 cases (8 per cent) on an average of 10 months (range 0–23 months) after the operation. Factors associated with the development of secondary epilepsy were localization of the aneurysm on the middle cerebral artery, temporary clipping intraoperatively, wrapping technique to treat the aneurysm, and vasospasm seen on the postoperative control angiogram. Intraoperative and/or postoperative ischaemia seems to be the crucial phenomenon favouring the development of epilepsy. Identification of the risk factors may help to focus the anti-epileptic prophylaxis in cases prone to develop seizures.     

Cerebriform intradermal naevus (a rare form of secondary cutis verticis gyrata)

BACKGROUND: Acquired cerebriform intradermal naevus (CIN) is a rare form of pseudo cutis verticis gyrata. CASE REPORT: A case of acquired CIN of the scalp in a 46-year-old male patient is presented. The clinical and histopathological presentations of CIN are described and the therapeutic possibilities are discussed. CONCLUSIONS: In each individual case the physician must decide whether to do surgery or follow a wait-and-see policy. There is little risk of malignant change of CIN, and surgical excision of such lesions often involves evident mutilation.     

Successful surgical treatment of secondary kwashiorkor after total gastrectomy: Report of a case

We report herein the case of a 56-year-old woman who developed secondary Kwashiorkor 9 years after undergoing a total gastrectomy for early gastric cancer. Until she began developing the symptoms of Kwashiorkor, including general fatigue, edema of the face and extremities, anemia, alopecia, and weight loss, she had been leading a normal life post-gastrectomy. Her symptoms were alleviated by total parenteral nutrition (TPN) therapy, but reappeared soon after TPN therapy was discontinued. Therefore, she required several subsequent courses of TPN. In an attempt to permanently resolve the ongoing Kwashiorkor symptoms, reconstructive surgery involving transposition of the jejunum from the previous Graham method to the interposition method was performed 10 years after the initial gastrectomy. After the second operation, her malnutrition was completely alleviated, and she has been in good health for the 8 years since. To our knowledge, there has been no other report of the symptoms of secondary Kwashiorkor after total gastrectomy being alleviated by altering the procedure of reconstruction of the intestinal tract. Thus, we recommend surgical treatment to alter the digestive continuity to a more physiological pathway for selected patients with secondary Kwashiorkor syndrome.     

Secondary hyperparathyroidism and acute tubular necrosis following renal transplantation

In the present study we investigated the relationship betweensecondary hyperparathyroidism in renal graft recipients andpost-transplantation acute tubular necrosis (ATN). Patientswere divided into two groups according to graft function: groupA consisted of 28 patients who had an uneventful postoperativeperiod and did not require haemodialysis. Group B comprised26 patients with primary non-function of the graft due to biopsy-provenATN who required continued haemodialysis for the first postoperativeweek or longer (mean 14.2 ±8.7 days). Both groups hadcomparable donor characteristics, HLA-matching and ischaemiatimes. All patients were given cyclospo-rin and low-dose prednisolonefor immunosuppression. Pretransplant levels of intact PTH weresignificantly greater in group B than in group A (203.5 ±193.1pg/ml versus 81.7±45.2 pg/ml, P<0.01). Group B patientshad more transplant biopsies (50 versus 7) and a longer hospitalizationtime (33.4 ± 10.9 days versus 21.9 ± 11.9 days,P<0.01), although serum creatinine on the day of dischargewas higher in group B (1.77 ± 0.51 mg/dl versus 1.5±0.45mg/dl, P<0.05). We conclude that patients with secondaryhyperparathyroidism as assessed by measuring circulating levelsof intact PTH have an increased incidence of ATN.     

腕部电烧伤肢体远端继发性坏死原因分型及治疗

１９８５年１月至１９９４年５月，我科共收治腕部电烧伤５４例、共７８个腕部受损。其中肢体远端原发性坏死者２５例，肢体远端继发性坏死及有继发性坏死倾向者１６例，占腕部电烧伤２０．５％（１６／７８）。继发性坏死者８例，有继发性坏死倾向经积极抢救治疗保住肢体者８例。在临床实践中，我们观察到腕部电烧伤远端肢体继发性坏死可分为三种类型：供血不足型，以动脉阻塞为主；血液瘀滞型，以静脉阻塞为主；血液粘滞度升高型，表现为微血管阻塞。并针对三种类型采用扩血管药物和抗血小板药物等不同预防治疗方法，临床上降低了截肢率，取得较为满意的效果。     

An Accurate Prediction of the pH Change Due to Degradation: Correction for a “Produced” Secondary Buffering System

Esmolol hydrochloride degrades in aqueous solutions by the hydrolysis of a labile aliphatic carboxy-ester group. The products are methanol and ASL-8123. The resulting aliphatic carboxylic acid moiety (ASL-8123) has a pK of 4.80, which is within 1 pH unit of the pH of the formulation. ASL-8123 therefore acts as a secondary buffer and minimizes the change in pH due to degradation. Equations are presented to calculate the change in the pH when the primary degradation product acts as a secondary buffer. This information can be used in the development of a parenteral product to predict, a priori, the concentration of buffer necessary for optimal pH maintenance. This knowledge can reduce the number of formulation screens required to determine the necessary buffer capacity for optimal drug stability.