The diagnostic value of bone scintigraphy in patients with low back pain

Bone scintigraphy has been studied in two groups of patients presenting with low back pain. In one group of 38 patients suffering "nonspecific" back pain, bone scintigraphy and laboratory findings were negative in 24. There were abnormal laboratory findings in all of the remaining 14 and 7 had positive bone scans indicative of clinically significant disease. Selection of patients for bone scintigraphy in this group should therefore be influenced by abnormal laboratory findings and elevation of the erythrocyte sedimentation rate in particular. By comparison, the bone scans were reviewed from another group of patients suffering previously known malignancy. Out of 138 patients, nearly 40% showed a positive bone scan due to subsequently proven metastasis. Bone scintigraphy was positive in a further 14% as a result of osteoporotic rib fracture and vertebral body collapse. In half of these, it was not possible to exclude malignancy by scintigraphy. The present findings indicate that bone scintigraphy is not a useful procedure in patients with long-standing low back pain who have normal radiographs and normal laboratory findings.     

Studies on corneal penetration ofp-hydroxybenzoic acid esters

Corneal permeability of variousn-alkylp-hydroxybenzoates (parabens) was studiedin vitro using excised rabbit corneas, and the effect of lipophilicity of parabens on the corneal permeability was also investigated. Permeability coefficients were obtained from the least-square linear regression after the steady state had been reached. Lipophilicity of parabens was calculated by distribution coefficients determined in octanol-S \(12_\phi [\kern-0.15em[ \) rensen’s buffer solution (pH 5.0). The relationship between lipophilicity and corneal permeability of parabens was not linear, but the optimum lipophilicity for the maximum permeation was found. The influence of tween 80 on corneal permeability of methyl and butylparaben was not significant.     

亚热带地区哺乳妇女能量需要量的观察

以同地区的53名非哺乳育龄妇女作对照,对262名产后0～6月乳母的体重、皮脂、上臂围、基础代谢率(BMR)、能量消耗和摄入量分别进行横向和纵向观察。结果表明,产后乳母体重和皮脂厚度逐渐下降,至第4个月基本稳定,平均减重4.2kg,估计孕期的贮脂大部分已消耗。上臂围无明显变化(P>0.05)。乳母的BMR在产后第1周较高(P<0.01),1～6月无明显变化(P<0.05),但比对照组高4～20％(P<0.05)。乳母在同一标准活动耗能与对照组接近(P>0.05)。轻体力劳动乳母日均活动耗能8.360MJ,估计泌乳耗能为2.807MJ/d。乳母能量摄入量比对照组多2.259MJ/d。作者认为,亚热带产后0～6月乳母在正常哺乳情况下,头4个月每日能量需要量应在平日消耗量基础上增加1.883MJ(450kcal),后雨月增加2.720MJ(650kcal),或整个阶段平均增加2.092MJ/d(500kcal/d),但此值仍需按泌乳量和正常体重变化加以调节。     

Collagen shields and intraocular drug delivery: concentration of gentamicin in the aqueous and vitreous of a rabbit eye after lensectomy and vitrectomy

Five albino New Zealand rabbits underwent bilateral lensectomy and vitrectomy. All left eyes were fitted with a collagen shield that had been soaked for 5 min in 2.0 mL of gentamicin solution (40 mg/mL for IV use). Right eyes were treated with fortified gentamicin drops (13.6 mg/mL) every 30 min for 12 hrs. Aqueous and vitreous specimens were obtained at the following time intervals: 1, 2, 4, 8, 12 and 24 hrs.We found the gentamicin concentrations to be higher in the aqueous of all eyes treated with fortified gentamicin drops. Only those eyes treated with fortified gentamicin drops attained a therapeutic drug level (4g–9g/mL) in the aqueous. Therapeutic drug levels were not attained in the vitreous of either treatment group.     

Apical opacity associated with pulmonary tuberculosis: high-resolution CT findings

To elucidate the nature of the apical opacity that is commonly seen in patients with tuberculosis--usually referred to as an "apical cap" or "apical pleural thickening"--18 patients with upper lobe tuberculosis were studied with high-resolution computed tomography (HRCT). All had a homogeneous apical opacity at least 1 cm thick on chest radiographs. Fifteen of the 18 had a history of pulmonary tuberculosis of more than 5 years duration, and nine showed evidence of ipsilateral pleurisy. HRCT scans at the apex of the thorax in all nine patients scanned at this level showed that extrapleural fat with interspersed vessels accounted for most of the plain radiographic opacity. Scans obtained at a level slightly above visible aerated lung showed extrapleural fat 3-25 mm thick peripherally and atelectatic lung centrally. At more caudal levels, at which both aerated lung and "thickened pleura" were visible on plain radiographs, HRCT showed extrapleural fat (3-20 mm thick), thickened pleura (1-3 mm thick), and atelectatic lung peripherally and areas of emphysematous bullae, bronchiectasis, and atelectatic lung centrally.     

Atrial morphologic features in tricuspid atresia.

We studied the atrial morphology in 110 hearts removed at autopsy from patients with tricuspid atresia. Ten of the patients had had a Fontan operation. We compared the findings in these hearts with those in 30 normal hearts. Prominent eustachian valves were common (40%). The tricuspid "dimple," present in 33 of 100 specimens, denoted the membranous atrioventricular septum and was never related to the right ventricle. Most interatrial communications (85/100) were nonobstructive. A minority of patients with obstructive interatrial communications (13/100 = small, 2/100 = severely obstructive) would be expected to benefit from balloon atrial septostomy early in life. Right atrial hypertrophy was greatest in specimens with restrictive interatrial communications (severely obstructive = 3.2 +/- 0.3 mm, small = 2.1 +/- 0.6 mm) and in those that had been subjected to a Fontan operation (3.2 +/- 0.7 mm), but thickness was also increased in hearts with nonobstructive interatrial communications (1.6 +/- 0.5 mm) compared with normal hearts (1.1 +/- 0.2 mm; p less than 0.001 versus all groups). Of the patients in the series, 11 of 100 had left juxtaposition of the atrial appendages, which may have important implications for the Fontan operation.     

The surgical anatomy of double-outlet right ventricle with concordant atrioventricular connection and noncommitted ventricular septal defect

In describing hearts with double-outlet right ventricle, we have had problems with how best to use the term noncommitted as applied to the ventricular septal defect. We reviewed, therefore, 63 hearts with double-outlet right ventricle in the setting of usual atrial arrangement and a concordant atrioventricular connection. From these, 18 hearts with potentially noncommitted defects were identified and studied in detail. The defect was unequivocally remote from the ventricular outflow tracts in 16 of these hearts, being perimembranous with excavation to open into the inlet of the right ventricle in 12, two of these also having straddling of an atrioventricular valve. One heart had a muscular defect situated in the inlet part of the muscular septum, whereas the defect was the ventricular component of an atrioventricular septal defect in the other three. In the remaining two hearts the defect was anatomically juxtaposed to a subarterial outlet. The pathway to the outflow tract, however, was obstructed by leaflets of a straddling valve. Our study shows, therefore, the need to distinguish between anatomic "commitment" of the defect from the problems in terms of commitment that may confront the surgeon in the operating room. Not only does the distance between the interventricular communication and one of the subarterial outflow tract need to be assessed (the anatomic commitment), but also the presence and nature of any intervening extraneous tissues (the surgical commitment) requires assessment.