老年人的疼痛问题

何为"老"?理解衰老的最好办法是将其视为一种从生到死的过度和渐变过程.在人们眼中,一旦到了80岁,身体就会变得很衰弱,易受伤,易残疾.但凡事都有例外,最典型的例子就是著名的黑人领袖纳尔逊.曼德拉,他虽年事已高(88岁),但他的才学、智慧、饱经磨难和乐观豁达都是少有人能及的.     

Palmar Type of Median Artery as a Source of Superficial Palmar Arch: A Cadaveric Study with Its Clinical Significance

The superficial palmar arch (SPA) and its contributing arteries are highly variable. The palmar type of median artery (PMA) can be involved in the formation of the SPA by replacing the superficial palmar branch of the radial artery (RA) or the ulnar artery (UA). The present study was undertaken to investigate the presence of the PMA and its contribution in the formation of SPA in 42 cadavers (84 upper limbs) of Indian origin. When there was a PMA, its outer diameter was measured in the carpal tunnel. The PMA was found in 13 upper limbs (15.4%), and of these ten incidences (11.9%), the PMA took part in the formation of SPA, and in three instances (3.5%), the PMA did not make up part of the SPA. Out of the ten cases in which the PMA contributed to the formation of SPA, in six cases (7.1%), the PMA anastomosed with the UA; in three cases (3.5%), the PMA anastomosed with both the UA and the RA, and in one incidence (1.1%), the PMA joined the arteria radialis indicis (deep branch of the RA) to complete the SPA. The outer diameters of the median arteries varied between 0.8 and 2.6 mm with the mean value of 1.7 mm. The present study concludes that the median–ulnar type of SPA was the most common type of SPA when the PMA was encountered as a source of superficial arterial arcade of the hand, followed by the radial–median–ulnar type. The vascular patterns found in this study are important to hand surgeons. The present study of PMA origin, course, and its contribution to the SPA will add to the existing knowledge of the vascular anatomy of forearm and hand.     

Experimental hepatic tumorigenicity by environmental hydrocarbon dibenzo[a,l]pyrene.

There is an evident need of low-cost vertebrates to be used in experimental carcinogenesis. Medaka (Oryzias latipes) provide a useful vertebrate model system for investigating tissue tropism of carcinogens and the action mechanisms of environmental contaminants posing a potential risk to human health. Juvenile medaka 2 months of age fed diets containing 100 ppm (dry weight basis) dibenzo[a,l]pyrene (DBP) for 28 days responded with hepatic neoplasia predominately of hepatocellular origin. When sampled 9 months following the termination of carcinogen exposure, medaka showed 26% incidence of neoplasia and 25% hepatic neoplasia, compared with 8% total neoplasia and 0% hepatic neoplasia in control fish. The predominant spontaneous neoplasms in this group of medaka were ovarian germ cell tumors. Hepatic neoplasia occurred at a higher incidence in female DBP-treated medaka than in males (11/29 vs 5/36). Nonneoplastic lesions observed in the livers of DBP-exposed fish included spongiosis hepatis, globular hyaline eosinophilic cytoplasmic inclusions in hepatocytes, foci of hepatocellular degeneration, extensive cytomegaly, and karyomegaly of hepatocytes. No activating exon I mutations in the one ras protooncogene examined were detected among six liver neoplasms. These results indicate that medaka are sensitive to the tumorigenic effects of the environmental carcinogen DBP, administered by dietary exposure.     

Excretory urography with iohexol: evaluation in children

A multicenter clinical study was conducted using iohexol, a second-generation nonionic contrast medium, for excretory urography performed in 130 children. Doses of iohexol (300 mg iodine/ml) ranged between 150 and 660 mgI/kg (0.5 and 2.2 ml/kg). Iohexol was tolerated well, and no significant adverse reactions occurred. Sixty-five iohexol urograms were evaluated to determine the minimum dose for adequate visualization of the kidneys and collecting systems. A dose greater than 300 mgI/kg (1.0 ml/kg) always resulted in a urogram of diagnostic quality, while visualization was insufficient for diagnosis in 10% of studies done with doses of 150-300 mgI/kg (0.5-1.0 ml/kg). Another 65 iohexol urograms were compared in a blinded manner with a similar number of studies performed using iothalamate meglumine at comparable iodine concentration and dose. Visualization of calyces and pelvoinfundibular structures achieved with iohexol was rated better with statistical significance, but there was no difference in visualization of the renal parenchyma or ureters. Use of iohexol in excretory urography may be advantageous in children who are at greatest risk for an adverse reaction to contrast media or in those most likely to benefit from use of a low osmolality contrast agent.     

Oligohydramnios associated with prostaglandin synthetase inhibitors in preterm labour

The use of prostaglandin synthetase inhibitors (indomethacin and ibuprofen) for greater than 72 h in women with preterm labour (n = 67) was significantly (P less than 0.001) associated with ultrasound-recorded oligohydramnios compared with the use of ritodrine or magnesium sulphate (control group, n = 67). Oligohydramnios developed in 26 of 37 women (70%) treated with indomethacin and 8 of 30 women treated with ibuprofen (27%) (P less than 0.01). Oligohydramnios developed in only two control subjects and one of these pregnancies was associated with intrauterine growth retardation. All 34 cases of oligohydramnios in the treatment group resolved after stopping medication, whereas the two in the control group did not resolve. No instances of renal failure, premature closure of the ductus arteriosus, pulmonary hypertension, or bleeding disorders were noted in any of the treated or control infants.     

The effect of cellular immune tolerance to HSV-1 antigens on the immunopathology of HSV-1 keratitis

Previous studies have revealed that herpes simplex virus type 1 (HSV-1) corneal stromal lesions do not develop in the absence of a cell-mediated immune (CMI) response to HSV-1 antigens. HSV-1 glycoprotein C (gC) has been shown to play an important role in the induction of the cytotoxic T lymphocyte (CTL) response to HSV-1 infections at anatomical sites other than the eye. Here we report that a deletion mutant lacking gC (gC-39) when used to infect the corneas of A/J mice was a poor inducer of both CTL and delayed type hypersensitivity (DTH) responses. We have also followed histologically and immunohistochemically the course of HSV-1 stromal disease in A/J mice following topical corneal (TC) infection with wild type (WT) HSV-1, TC infection with gC-39 HSV-1, and simultaneous TC and anterior chamber (TC + AC) infection with WT HSV-1. The latter type of infection has been shown to induce a profound state of DTH and CTL tolerance of HSV-1 antigens. Following TC infection with WT HSV-1, stromal disease progressed to severe ulcerative keratitis with neovascularization by day 21. Histologic and immunohistochemical analysis revealed a predominantly mononuclear infiltrate consisting of numerous plasma cells as well as L3T4+ (T helper/inducer) and Lyt-2+ (T suppressor/cytotoxic) T lymphocytes. Following TC infection with gC-39, or simultaneous TC + AC infection with WT HSV-1, the severity of stromal disease did not progress beyond day 7. On day 21, there was at most a mild stromal cellular infiltrate consisting predominantly of polymorphonuclear neutrophils. These findings indicate that early stromal disease consists of a nonspecific inflammatory response, but severe stromal disease involves a CMI response to HSV-1. AC injection of HSV-1 inhibits the CMI response, thereby halting the progression of stromal disease. Similarly, gC-39, a poor inducer of CMI responses, is also a poor inducer of stromal disease.     

A reproducible method for injecting the mouse corneal stroma

An improved delivery system for injecting the mouse corneal stroma was developed. This system incorporates the following features: a repeating dispenser that eliminates inaccuracies in depressing a syringe plunger, foot activation which frees both hands for manipulating the needle and permits constant observation of the injection site, and a flexible 30-cm, 32-gauge stainless steel needle with a 30 degrees bevel and a locking hub that resists pulsation due to back pressure while permitting freedom of motion by the operator. These injections were done while observing the cornea with a vertically mounted slit lamp, ideally suited for examining and photographing the eyes of laboratory animals. The reproducibility of the new delivery system, expressed in terms of the signal-to-noise ratio, was estimated and compared with that of a hand-held microsyringe by injecting a solution of radioactive chromium into the corneal stroma of A/J mice. The eyes were removed within 1 hr of injection, and the amount of chromium in each eye was determined in a gamma counter. The new delivery system had significantly (P less than 0.05) greater reproducibility than the hand-held syringe and could be calibrated to deliver up to 0.65 microliter to the mouse cornea.