Caisson disease of bone

Caisson disease of bone, which may affect compressed air workers and divers, is characterized by regions of bone and marrow necrosis that may lead to secondary osteoarthrosis of the hip and shoulder joints. A review of the pathologic, radiologic, and clinical aspects demonstrated uncertainties in the exact etiology. Early diagnosis is often not possible because of the delayed appearance of radiologic abnormalities. Research into these two aspects of this condition was carried out by the Medical Research Council Decompression Sickness Research Team in Newcastle upon Tyne over a ten-year period (1972 to 1982). Because no suitable animal model exists for the study of this condition, bone and marrow necrosis was produced by embolism of bone blood vessels with glass microspheres. With this model, it was shown that the presence of bone and marrow necrosis could be detected by bone scintigraphy using 99mTc-MDP and by measuring changes in serum ferritin concentration at a much earlier stage than was possible by radiography. However, only the former method has proved useful in clinical practice. Investigations into the etiology of caisson disease of bone have shown evidence for an increase in marrow fat cell size resulting from hyperoxia. This phenomenon may play a role in the production and localization of gas bubble emboli, which are thought to be the cause of the bone and marrow necrosis.     

Early indices of warm ischemic damage in autotransplanted canine kidneys preserved by simple hypothermic storage

After measurement of normal renal function, dog kidneys (n = 52) were subjected to 3, 15, or 30 min of normothermic warm ischemia (WI). After 24 hr of preservation by simple hypothermic storage (SHS) in a modified Collins solution, autotransplant was done and renal function was again measured beginning at 1 hr. Compared with preharvest values, kidneys with minimal (3 min) WI had significantly decreased clearances of creatinine (Cr) and para-aminohippuric acid (PAH), PAH extraction, absolute and fractional Na reabsorption, Na excretion, and urinary Na concentration; no change in urine flow rate or K excretion; and significantly increased fractional excretion of Na, K, and H2O. Compared with minimal WI, 30-min WI produced further significant decreases in clearances of Cr, PAH, and PAH extraction; and further increases in fractional excretion of Na, K, and H2O. Urine flow was also decreased by about half and urine Na concentration rose significantly. Several parameters were very significantly correlated with the length of WI, but the most reliable index was the fractional reabsorption of Na. When several functional parameters were used together, kidneys with significant (30 min) WI prior to preservation could be identified with a high degree of statistical reliability.     

Endothelial and smooth muscle properties of coronary and mesenteric resistance arteries in spontaneously hypertensive rats compared to WKY rats

Summary— To investigate if the functional alterations observed in resistance arteries of spontaneously hypertensive rats (SHRs) were also present at the coronary level, in vitro experiments were performed in mesenteric resistance arteries (MRA) and in right (RIC) and left interventricular coronary (LIC) arteries taken from 15–25-week-old SHR and age-matched Wistar Kyoto rats WKYs. Using a passive extension protocol, internal diameters corresponding to 100 mmHg intraluminal pressure (D₁₀₀) were determined and vessels were set up to a normalized internal diameter (0.9 D₁₀₀). SHR mesenteric resistance arteries had a significantly smaller diameter compared to WKY arteries, whereas both types of SHR coronary arteries had a greater diameter compared to those of WKY rats. In arteries in the absence of contracting agonist, nitro-L-arginine (NOLA, 100 μM) induced a progressive rise in basal tone, which could be reversed by subsequent addition of L-arginine (100 μM) but not D-arginine (100 μM). When expressed as percent of maximal contractions induced by agonists (noradrenaline, NA [10 μM] in MRA; serotonin, 5-HT [10 μM], in RIC and LIC), these contractions were significantly stronger in WKY compared to SHR coronary and mesenteric resistance arteries. In NA-precontracted MRA and 5HT-precontracted coronary arteries in the presence of indomethacin (10 μM), the magnitude of acetylcholine-induced maximal relaxations (expressed as percent of maximal contractions induced by agonists) was greater in WKY compared to SHR arteries. After a 30-min incubation period, NOLA (100 μM) completely inhibited relaxations induced by acetylcholine (0.01–10 μM) in all types of precontracted arteries. Subsequent additions of sodium nitroprusside, (SNP, 10 μM) induced complete relaxations in all preparations. These results show that a basal release of NO or NO-like compound by endothelial cells is present in isolated mesenteric resistance and coronary arteries of WKY rats and SHRs. The contribution of endothelium-derived relaxing factor-nitric oxide (EDRF-NO) to arterial tone was lower in MRA compared to coronary arteries in both strains and in SHR compared to WKY arteries. In the SHR preparations, the impaired relaxation induced by acetylcholine appeared to be due to a functional alteration of the endothelium in the presence of normal reactivity of the smooth muscle cells.     

麦冬类中药组织切片计算机三维重建图鉴

利用计算机技术实现麦冬类中药组织连续切片三维重建与动态显示,为计算机辅助生药学鉴定和教学提供了新的三维图像技术和研究资料。     

表小檗碱对α受体的作用

表小檗碱(epiberberine,EB)是从湖北产黄连(Coptis chinensis Franch)中提取的一种生物碱,属苯喹嗪类原小檗碱,对其药理作用的研究资料甚少,未见其对α肾上腺素体作用的报道。资料表明,许多原小檗碱类化合物有α受体阻滞作用,为从该类化合物中选择     

The management of the painful first metatarsophalangeal joint in the older patient. Arthrodesis or Keller's arthroplasty?

We report a prospective randomised trial comparing Keller's arthroplasty and arthrodesis of the first metatarsophalangeal joint for the management of symptomatic hallux valgus and hallux rigidus in the older patient. In 81 patients (110 feet), with a minimum of two years follow-up, both procedures gave a similar degree of patient satisfaction and symptom relief. The incidence of metatarsalgia was also similar. As there were no obvious advantages to arthrodesis, and since six out of 50 arthrodesed toes required revision, we suggest that Keller's arthroplasty is the better operation in these patients.     

Outcomes in children with nasolacrimal duct obstruction: Significance of persistent symptoms while stents are in place.

To evaluate the correlation between persistent symptoms while stents are in place and final outcome in children with nasolacrimal duct obstruction (NLDO). A retrospective observational case series, with medical record review that included indications for surgery, surgical procedure, presence of symptoms while stents were in place, and final outcome after stent removal. Twenty-eight children with NLDO had nasolacrimal duct stents placed in 42 eyes. Twenty-one of the 42 eyes (50%) had minimal or no signs or symptoms of NLDO while stents were in place, and 18 of 21 (86%) were symptom-free after stent removal. Twenty-one of the 42 eyes (50%) remained symptomatic while stents were in place. Eleven of these 21 eyes (52%) had good outcomes after stent removal. Ten (48%) of these patients had persistent symptoms after stent removal requiring further treatment. The prognosis for a good outcome is excellent if symptoms of NLDO resolve while stents are in place. The prognosis is poorer if symptoms of NLDO persist, but more than half of such patients still have good outcomes. Careful counseling of parents regarding these outcomes should be performed before considering additional interventions.