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.     

Fracture behaviour of zirconia FPDs substructures

Summary The purpose of this study was to evaluate the occurrence of superficial flaws after machining and to identify fracture initiation and propagation in three‐unit heat‐treated machined fixed partial dentures (FPDs) substructures made of hot isostatic pressed (HIPed) yttria‐stabilized tetragonal zirconia polycrystal (Y‐TZP) after loaded to fracture. Four three‐unit HIPed Y‐TZP‐based FPDs substructures were examined. To evaluate the occurrence of superficial flaws after machining, the surfaces were studied utilizing a fluorescent penetrant method. After static loading to fracture, characteristic fracture features on both mating halves of the fractured specimens were studied using a stereomicroscope and a scanning electron microscope. Grinding grooves were clearly visible on the surfaces of the machined FPDs substructures, but no other flaws could be seen with the fluorescent penetrant method. After loading to fracture, the characteristic fracture features of arrest lines, compression curl, fracture mirror, fracture origin, hackle and twist hackle were detected. These findings indicated that the decisive fracture was initiated at the gingival embrasure of the pontic in association with a grinding groove. Thus, in three‐unit heat‐treated machined HIPed Y‐TZP FPDs substructures, with the shape studied in this study, the gingival embrasure of the pontic seems to be a weak area providing a location for tensile stresses when they are occlusally loaded. In this area, fracture initiation may be located to a grinding groove.     

The incidence of transient hyperprolactinemia in gonadotropin-stimulated cycles for in vitro fertilization and its effect on pregnancy outcome

The incidence of transient hyperprolactinemia and its impact on in vitro fertilization (IVF) were determined in 151 euprolactinemic women with tubal infertility undergoing an identical gonadotropin stimulation for IVF. Prolactin (PRL) levels were measured on the morning of cycle day 3, days of human chorionic gonadotropin (hCG) administration, and peak estradiol (E2), and in the midluteal phase. Women were divided into high (H: peak E2 greater than 1,000 pg/mL, n = 51), intermediate (I:peak E2: 500 to 800 pg/mL, n = 50), or low (L:peak E2 less than 400 pg/mL, n = 50) E2 response groups. There was no difference in the incidence of hyperprolactinemia on cycle day 3 between the response groups (H:16%, I: 12%, and L:8%). However, high responders had a higher incidence of hyperprolactinemia than intermediate or low responders on all other study days. The incidence of hyperprolactinemia was greater than baseline (cycle day 3) only in the high responders on the day of peak E2. Serum prolactin was strongly correlated with peak E2 (r = 0.41). There were no differences in the number of preovulatory oocytes retrieved or fertilized or the pregnancy rates between hyperprolactinemic and euprolactinemic patients in each response group or when all hyperprolactinemic and euprolactinemic patients, regardless of E2 response, were compared. Transient hyperprolactinemia during gonadotropin stimulation for IVF occurs and correlates with E2 response but has no impact on IVF outcome.     

Ovarian stimulation for in vitro fertilization in low-responder patients using pulsatile intravenous follicle stimulating hormone

There is a subset of patients who fail to respond adequately to exogenous gonadotropin stimulation for in vitro fertilization (IVF). In this study, six such low-responder patients who had inadequate stimulations with high-dose intramuscular (im) follicle stimulating hormone (FSH) were treated in a subsequent cycle with pulsatile intravenous (iv) FSH. A paired analysis was performed to compare the cycles using high-dose im FSH with those using pulsatile iv FSH. Trough serum FSH levels were significantly higher with pulsatile iv FSH. No significant difference was noted in the stimulation characteristics or the number or quality of oocytes retrieved and embryos transferred. No pregnancies occurred in either group. While pulsatile iv administration of gonadotropin increases serum FSH levels, it does not appear to have a major impact on follicular stimulation or outcome in low-responder patients undergoing IVF.     

Preclinical abortions: incidence and significance in the Norfolk in vitro fertilization program

Clinical and prognostic significance of preclinical abortions in assisted reproduction is ill defined. Strict diagnostic criteria include a transient and synchronous elevation of serum beta-human chorionic gonadotropin (hCG), estradiol, and progesterone levels 13 days after hCG administration, ending in a bleeding episode no more than 14 days after the missed period. The preclinical abortion study group (54 patients, 178 cycles) was compared with matched control groups A (54 patients, 132 cycles) and B (54 patients, 155 cycles), representing normal term pregnancies and all outcomes, respectively. Control group C included the overall population during the study period. The abortion rate per transfer (preclinical abortion and total miscarriage rates) and total pregnancy wastage in the study group were significantly higher; the ongoing pregnancy rate was significantly lower. Preclinical abortion should be considered as a true reproductive failure with similar implications.     

Carriage of Haemophilus influenzae and Streptococcus pneumoniae in healthy Chinese and Vietnamese children in Hong Kong

Nasopharyngeal carriage of Haemophilus influenzae and Streptococcus pneumoniae was studied in 621 healthy Chinese children and 300 healthy Vietnamese children aged from 2 months to 5 years in Hong Kong. The carriage rate of H, influenzae type b in Vietnamese children was 1.3% (CI 0.04-2.63%); it was zero in Chinese. The carriage rate of non-typable H. influenzae was 5.8% (CI 1.4-7.6%) in Chinese and 65.4% (CI 58.9-69.8%) in Vietnamese. The carriage rates of S. pneumoniae were 10.8% (CI 8.3-13.2%) and 55.7% (CI 50.1-61.3%) in Chinese and Vietnamese children, respectively. Univariate and multivariate logistic regression analyses were performed to search for factors associated with differences in carriage rates of both H. influenzae and S. pneumoniae between Chinese and Vietnamese children. Although older age, smaller living area and parental smoking were associated with higher carriage rates, these could not explain the remarkably low carriage rates of both bacteria in Chinese children.     

The perimenopausal patient in in vitro fertilization: the use of gonadotropin-releasing hormone

The perimenopause, incipient ovarian failure, is a major problem in stimulation failures during an in vitro fertilization program. This must be recognized as not necessarily related to age but also associated with adnexal inflammatory and operative processes. Although ovulation occurs uninterruptedly, the follicle-stimulating hormone in the early follicular phase is elevated and the luteinizing hormone is normal. Characteristically, there is no estradiol response to human menopausal gonadotropin therapy or a rapid response with a premature luteinizing hormone surge. These problems sometimes may be overcome with pulsatile intravenous gonadotropin-releasing hormone therapy, 5 or 10 micrograms/90 or 120 minutes. The major therapeutic problem is in the identification of a luteinizing hormone surge in these patients. Of eight women who were treated, two failed to respond with follicular maturation, three either had no oocytes aspirated from apparently postmature follicles or had postmature oocytes; and one had treatment cancelled due to ovulation. The four latter patients may have failed because of unrecognized ovulation. In the remaining two patients, one oocyte was fertilized and transferred, and one pregnancy occurred.     

In vitro fertilization and embryo transfer (IVF/ET): An established and successful therapy for endometriosis

The purpose of this report is to present a 6-year experience in the management of endometriosis with in vitro fertilization and embryo transfer (IVF/ET). We divided 136 patients who underwent 280 cycles into three groups: (1) previous history of endometriosis but normal pelvis at the time of oocyte retrieval, (2) stages I–II endometriosis (revised AFS classification), and (3) stages III–IV endometriosis. The stimulation protocols, estradiol (E₂) responses, and distribution of terminal E₂ patterns were similar in all groups. Group 3 had significantly fewer preovulatory and immature oocytes retrieved and fewer embryos transferred. The fertilization rate and the per cycle/per transfer pregnancy rates were similar in all groups. The miscarriage rate was higher in group 3, and the on-going pregnancy rate per cycle was lower, Luteal phase E₂ and progesterone levels were comparable in all groups. No differences were found when groups 2 and 3 were analyzed for the presence of one or two ovaries or the presencelabsence of ovarian endometriosis. The overall fertilization rate, the per cycle/per transfer pregnancy rates, and the miscarriage rate were similar to those of tubal factor patients. We underscore the excellent out-come of patients with minimal or mild endometriosis in IVF/ET. We conclude that patients with moderate or severe endometriosis have a compromised reproductive potential, probably because of a reduced oocyte recovery rate and poor embryo quality.     

Genetic Engineering and Medical Ethics

In the introduction I express the need of introducing the point of view of Ethics when we are dealing with problems of science, technology, and especially medicine. In the first part of my presentation I deal with the problem of the value of human life, coming to the conclusion that human life might not be completely absolute, but is extremely important and “ceteris paribus” should be respected, and the problem of when it starts. Some of the main arguments are discussed. In this connection the question of abortion is briefly discussed. In the second part I deal with some problems related to human reproduction. Most people will be willing to support programmes for treating individuals with genetic disease; but at the same time the dangers of increasing depersonalization of the reproductive process are pointed out. In the third part I take up the problem of In Vitro Fertilisation. IVF has certainly brought benefits to some couples suffering from infertility, but at the same time it has raised quite a few human and moral problems. Is it permissible to fertilise an egg with a donor sperm, replacing the embryo in the womb? What about fertilising a donor egg with the husband's sperm? Is it acceptable to store or freeze embryos for future use? Is it moral to implant such an embryo in a woman who has no genetic relationship with the embryo? Is it moral to use surrogate mothers? Is it moral for ‘spare’ embryos to be killed or used as tissue for research? At the end I stress the need of dialogue between life sciences and ethics.