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71.
Gonadotropin-releasing hormone (GnRH) and olfactory neurons migrate together from the olfactory placode, and GnRH neurons eventually reside in the hypothalamus. Hypogonadism in male infants may be diagnosed in the first 6 months of life but cannot be diagnosed during childhood until puberty occurs. Patients with low serum testosterone and low serum gonadotropin levels have idiopathic hypogonadotropic hypogonadism (IHH). Mutations in three genes (KAL1, FGFR1, and GNRHR) comprise most of the known genetic causes of IHH. Treatment with testosterone is indicated if fertility is not desired, whereas GnRH or gonadotropin treatment induces spermatogenesis and fertility.  相似文献   
72.
The distinction between seminoma and embryonal carcinoma based on morphology alone can sometimes be problematic, requiring the use of immunohistochemistry to facilitate diagnosis. D2-40 is a monoclonal antibody that reacts with an oncofetal antigen expressed by fetal germ cells and testicular germ cell tumors. The diagnostic value of D2-40 immunohistochemistry in distinguishing seminoma from embryonal carcinoma has not been determined. D2-40 immunoreactivity was evaluated in a series of testicular germ cell tumors and compared with that of KIT (CD117) and CD30, to assess the relative utility of this marker in discriminating between seminoma and embryonal carcinoma. Forty testicular germ cell neoplasms were examined, which included 19 seminomas, three embryonal carcinomas, three teratomas, one yolk sac tumor, and 14 mixed germ cell tumors. The 14 cases of mixed germ cell tumors contained components of seminoma (n=7), embryonal carcinoma (n=11), teratoma (n=10), yolk sac tumor (n=2), and choriocarcinoma (n=1). All cases of pure seminoma and the seminomatous components of mixed germ cell tumors exhibited positive immunoreactivity for D2-40. Focal positivity for D2-40 was also observed in 29% of the embryonal carcinoma samples. D2-40 immunoreactivity in seminomas was characterized by diffuse membrane staining, whereas for embryonal carcinomas, staining was focal and distributed along the apical surfaces of the neoplastic cells. Immunohistochemical staining for KIT was observed in 92% of the seminoma samples and in none of the embryonal carcinomas. Conversely, CD30 expression was identified in 93% of the embryonal carcinoma samples and in none of the seminomas. Other germ cell components showed no immunoreactivity for D2-40, KIT, or CD30. KIT and CD30 are effective immunohistochemical markers in separating seminoma from embryonal carcinoma. Although a highly sensitive marker for seminomas, D2-40 positivity was also observed in a subset of embryonal carcinomas, thus limiting the utility of this antibody for discriminating between these two malignancies.  相似文献   
73.
74.
The aim of this study was to determine whether the natural course of urethral stricture disease could be modified following urethrotomy by teaching patients intermittent self-catheterization. Preliminary results in 42 patients show that postoperative urine flow rates can be maintained if this method of 'low-friction' catheterization is adopted. The technique has been well received by an elderly group of patients and can be recommended for wider use.  相似文献   
75.
In 1980 a syndrome was first described in two adult males, consisting of macrocephaly, pigmented macules on the glans and shaft of the penis, and hamartomatous intestinal polyps. Since then, 10 additional cases have been identified. Herein, we present two new cases and review the cutaneous manifestations as well as additional features in patients with the Ruvalcaba-Myhre-Smith syndrome.  相似文献   
76.
Objectives: The purpose of this study was to determine if a device placed externally around the aortic root decreases regurgitant flow in acute aortic regurgitation. Background: Aortic regurgitant flow is dependent on central aortic pressure and the aortic root and leaflet geometry. It may be possible to decrease aortic regurgitant severity by reducing aortic root size or dimension changes. Methods: Aortic regurgitation was created in eight calf heart specimens suspended in a continuous flow system. Retrograde and antegrade aortic flow and distending aortic pressure were measured at baseline and after placement of an external aortic device at the level of the aortic annulus. In two additional specimens, the incompetent aortic valve was visualized fiberoptically before and after placement of the external device. Acute aortic regurgitation was created surgically in four live calves by excising a portion of the aortic leaflets. Antegrade and retrograde flow, left ventricular pressure, and central aortic pressure were measured at baseline, after creation of aortic regurgitation, and after placement of the external device. Results: In the in vitro calf specimens, regurgitant flow decreased from 46.9 cc/sec to 15.1 cc/sec (66.0%± 21.8% decrease) after placement of the external device (p < 0.001). The regurgitant orifice area decreased from 0.13 ± 0.04 cm2 to 0.04 ± 0.02 cm2 after device placement (p < 0.001). Antegrade flow was reduced to a smaller extent (20.0%± 19.2% decrease) by the device (p < 0.05). Placement of the device around the aorta resulted in improved coaptation of the leaflets with a marked reduction in defect size by endoscopic visualization. Use of the external aortic device was associated with improvement in aortic regurgitant severity in three of four calves with surgically created aortic regurgitation. Concluslons: In these preliminary studies, acute experimental aortic regurgitant severity is decreased by the use of an external aortic device, probably due to reduction in aortic annular dimension changes and improved aortic leaflet apposition. Further studies are needed to determine the effectiveness of this device in chronic aortic regurgitation. (J Card Surg 1994;9:304–313)  相似文献   
77.
Body composition of 24 rural Beninese women was assessed in a pre- and a postharvest season by using skinfold-thickness measurements, bioelectrical-impedance analysis (BIA), and deuterium oxide (D2O) dilution. Fat mass assessed by D2O dilution was 12.3 +/- 3.3 kg; by skinfold-thickness measurements, 13.8 +/- 3.3 kg; and by BIA, 14.1 +/- 2.9 kg. Fat mass assessed by D2O was significantly lower (P less than 0.05) than fat mass assessed by the other two methods. Body weight in the postharvest season was 0.8 +/- 1.6 kg higher (P less than 0.05) than during the preharvest season. All three methods demonstrated that there were no significant changes in fat mass but that fat-free mass increased significantly (P less than 0.05) from pre- to postharvest season.  相似文献   
78.
Although claims data are increasingly being used to measure and manage the cost and quality of health care, few studies have evaluated algorithms developed for such analyses. Therefore, the present study was performed to evaluate prospectively a previously published algorithm used to identify women with the new diagnosis of carcinoma of the breast. This algorithm had been developed from the patterns of claims that suggested common clinical presentations of carcinoma of the breast. In the present study, this algorithm was used to identify 177 potential cases of women with newly diagnosed carcinoma of the breast from the claims database of a large health maintenance organization (HMO). The algorithm's positive predictive value for cases identified in the present study was 83% (147/177). To attempt to improve upon the positive predictive value, multiple modifications of the algorithm were performed. The previously defined best modification of the initial algorithm yielded a positive predictive value of 84% (147/174) in the present study with the loss of none of the true positive cases. These results demonstrate that logic-based algorithms can be used as a valid and efficient method of identifying large numbers of new breast cancer cases from claims data. This algorithm provides a powerful tool to perform health care analysis and research for women with newly diagnosed carcinoma of the breast.  相似文献   
79.
The present study has employed in vitro electrophysiology and radioligand binding assays to determine whether dopamine and adenosine receptors interact with each other on rat vagal afferent neurons. Preincubation of the isolated rat nodose ganglion with the adenosine A2a agonists CGS 21680 or DPMA (Both 1 μM) resulted in a functional antagonism of the ability of dopamine to depolarise the preparation. Specifically, the concentration-response curve to dopamine was significantly shifted to the right in the presence of CGS 21680 and DPMA. On the other hand, adenosine itself, A1 and A3 receptor agonists and ATP were all incapable of modulating the electrophysiological response to dopamine. In contrast to the nodose ganglion, CGS 21680 did not significantly affect the ability of the dopamine D2 ligands quinpirole or raclopride to displace [125I]NCQ298 binding to dopamine D2 receptors in membranes prepared from rat dorsal brain stem. These data indicate the presence of an interaction between high affinity adenosine A2 receptors and dopamine D2 receptors on the soma of rat vagal afferent neurons, whereas the situation in the brain stem remains less clear. Received: 17 September 1996 / Accepted: 20 October 1996  相似文献   
80.
The current study presents both longitudinal behavioral data and functional activation data documenting the effects of early focal brain injury on the development of spatial analytic processing in two children, one with prenatal left hemisphere (LH) injury and one with right hemisphere (RH) injury. A substantial body of evidence has shown that adults and children with early, lateralized brain injury show evidence of spatial analytic deficits. LH injury compromises the ability to encode the parts of a spatial pattern, while RH injury impairs pattern integration. The two children described in this report show patterns of deficit consistent with the site of their injury. In the current study, their longitudinal behavioral data spanning the age range from preschool to adolescence are presented in conjunction with data from a functional magnetic resonance imaging (fMRI) study of spatial processing. The activation results provide evidence that alternative profiles of neural organization can arise following early focal brain injury, and document where in the brain spatial functions are carried out when regions that normally mediate them are damaged. In addition, the coupling of the activation with the behavioral data allows us to go beyond the simple mapping of functional sites, to ask questions about how those sites may have come to mediate the spatial functions.  相似文献   
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