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251.
New procedures of laser therapy and chemotherapy have extended the scope of application of organ-saving treatment at advanced stages of retinoblastoma in childhood, thus making it possible to preserve the eye fully functional or cosmetic. Not having to perform such mutilating procedures as ophthalmectomy or eye socket exenteration contributes to psychological and physical rehabilitation. At the same time, as a comparison of the results of surgery carried out at initial stages and surgery-free treatment showed that palliative therapy is characterized by impressive rates of 5-year survival. New vistas have opened of in the management of pediatric retinoblastoma, particularly in cases of stage III tumor and bilateral involvement.  相似文献   
252.
Ethanol exposure affects cellular mechanisms involved in the regulation of calcium (Ca2+) homeostasis. Neurotrophins, such as nerve growth factor (NGF), stabilize intracellular Ca2+([Ca2+]i) during a variety of neurotoxic insults. In this study, changes in [Ca2+]i during treatment with ethanol and NGF were measured at the cell body of neurons using the Ca2+ indicator indo-1. Cultured postnatal day-of-birth (P0) septohippocampal (SH) neurons that were labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate (DiI), increased [Ca2+]i in response to ethanol. This response was dose-related. P0 SH neurons treated with NGF had lower [Ca2+]i than neurons withdrawn from NGF, implying that NGF may modulate Ca2+ homeostasis in these neurons. NGF also prevented the dose-related increase in [Ca2+]i in ethanol-treated SH neurons. The SH neurons increased [Ca2+]i when they were stimulated with 30 mM potassium chloride (KCl). Ethanol inhibited the potassium-stimulated change in [Ca2+]i but the combination of ethanol and NGF caused [Ca2+]i to increase with 100 mg% and 400 mg% ethanol and to decrease to a lower level with 200 mg% ethanol. These data were compared to data from previously published similar aged medial septal (MS) neurons (B. Webb, S.S. Suarez, M.B. Heaton, D.W. Walker, Clin. Exp. Res. 20 (1996) 1385-1394) and with embryonic gestational day 21 (E21) SH neurons (B. Webb, S.S. Suarez, M.B. Heaton, D.W. Walker, Brain Res. 729 (1996) 176-189). Differences in [Ca2+]i responses were observed in ethanol and NGF-treated postnatal SH neurons compared with P0 MS neurons and E21 SH neurons. Of these differences, most occurred during the combined treatment with ethanol and NGF compared with either treatment alone.  相似文献   
253.
The mouse neurological mutant lurcher (Lc) results from a semidominant mutation. Heterozygous Lc/+ mice are viable but ataxic because Lc/+ Purkinje cells die by apoptosis within the first 3 weeks of life. Lc/Lc mice die shortly after birth. To aid in understanding the function of the lurcher gene product, we have examined the embryonic development of homozygous lurcher animals. The ratio of +/+:Lc/+:Lc/Lc animals did not deviate significantly from the expected 1:2:1. Homozygous lurcher mice at P0 were found to be normal under gross morphological examination. However, these mice weighed less, lacked milk in their stomach, and died within the first day of life. No resorbed embryos were found at embryonic day (E) 17.5, indicating that all homozygous lurchers survived until birth. Histological examination of P0 animals revealed that in homozygous lurcher mice the patterning of the brain is normal but that there has been a massive loss of hindbrain neurons during embryonic development. A particularly conspicuous consequence of the Lc/Lc genotype at birth is the complete absence of large neurons comprising the trigeminal motor nucleus. These neurons arise normally and are maintained until E15.5. However, beginning at E15.5 large numbers of pyknotic cells are evident in the trigeminal motor nucleus, suggesting that these cells die coincident with their terminal differentiation in the developing hindbrain. Because the trigeminal motor nucleus controls muscles required for suckling, these results suggest an explanation for the neonatal death of homozygous Lc animals. These data demonstrate that the severe and dose-dependent developmental consequences of lurcher gene action result from degeneration of distinct neuronal populations on maturation in the developing CNS.  相似文献   
254.
BACKGROUND: Angiosarcomas are uncommon soft tissue neoplasms with a predilection for skin and superficial soft tissues. CASES: Two cases of angiosarcoma occurred at unusual sites, the parotid gland and lung. The parotid lesion was characterized by malignant cells present singly, in loose groups, in tight three-dimensional aggregates and in acinar formation initially misinterpreted as an adenocarcinoma. The lung mass showed malignant cells in association with vascular endothelium, suggestive of angiosarcoma. Both cases were negative for Ulex europaeus and Factor VIII-related protein but demonstrated strong immunopositivity for CD31, a highly specific endothelial marker. CONCLUSION: In the absence of vasoformative structures, important diagnostic pitfalls are pseudovascular adenoid squamous cell carcinoma, poorly differentiated adenocarcinoma, melanoma and lymphoma. Immunocytochemical studies and clinical history are essential to the correct diagnosis.  相似文献   
255.
Transforming growth factor beta (TGF-beta) has been implicated in the pathogenesis of various human diseases. Synthetic TGF-beta antagonists therefore could have therapeutic utility. Here we show the development of such compounds. Three synthetic pentacosapeptides designated beta125-(41-65), beta225-(41-65), and beta325-(41-65), whose amino acid sequences correspond to the 41st to 65th amino acid residues of TGF-beta1, TGF-beta2, and TGF-beta3, respectively, inhibit the binding of 125I-labeled TGF-beta isoforms to TGF-beta receptors in mink lung epithelial cells with IC50 of approximately 0.06-2 microM. beta125-(41-65) blocks TGF-beta1-induced growth inhibition and TGF-beta1-induced plasminogen activator inhibitor-1 expression in these cells. The variants designated beta125-(41-65)W52A/D55A and beta325-(41-65)R52A/D55A, in which both Trp52/Arg52 and Asp55 are replaced by alanine residues, do not have TGF-beta antagonist activity. Multiple conjugation of beta125-(41-65) to carrier proteins enhances its antagonist activity but also confers partial agonist activity as measured by DNA synthesis inhibition. These results suggest that the (W/R)XXD motif is important for the activities of these TGF-beta peptide antagonists and that this motif may be the active site sequence of TGF-beta.  相似文献   
256.
OBJECTIVES: To estimate and compare recurrence rates, index of recurrence, and disease-free interval in patients with superficial recurrent bladder cancer receiving bacille Calmette-Guérin (BCG) or interferon (IFN) for immunoprophylaxis. METHODS: One hundred twenty-two patients with recurrent superficial Stage pT1, grade 1 to 3 tumors were enrolled in a randomized, prospective, multicenter trial with two treatment arms of endovesical immunoprophylaxis: 150 mg of BCG versus 54 MU of recombinant IFN-alpha-2a. Administration was weekly during the first month, biweekly for 2 months, and monthly for 9 months. Both groups were similar with regard to tumor stage, grade, size, and number. RESULTS: Sixty-one patients were evaluable in the BCG group and 49 in the IFN group. Tumors recurred in 34 (69.4%) of 49 patients in the IFN group (890 months of follow-up) and in 24 (39.3%) of 61 in the BCG group (1272 months of follow-up). The total number of recurrences (28 for BCG, 47 for IFN), disease-free interval (mean 19.3 months for BCG, 15.3 months for IFN), and index of recurrence (2.2 for BCG, 5.5 for IFN) were statistically significant (P = 0.001) in favor of BCG. Progression to invasive carcinoma was similar in both study arms. Neither systemic nor local side effects were seen in the IFN group. However, the previously reported toxicity of BCG was confirmed. CONCLUSIONS: According to our trial, BCG remains the most efficacious agent for immunoprophylaxis of recurrent superficial bladder tumors.  相似文献   
257.
258.
BACKGROUND: The majority of people infected with HIV-1 live in Africa, yet little is known about the natural history of the disease in that continent. We studied survival times, disease progression, and AIDS-defining disorders, according to the proposed WHO staging system, in a population-based, rural cohort in Uganda. METHODS: In 1990 we recruited a random sample of people already infected with HIV-1 (as prevalent cases) detected during the initial survey round of a general-population study to form a natural-history cohort. Individuals from the general-population cohort who seroconverted between 1990 and 1995 (incident cases) were also invited to enroll. Participants were seen routinely every 3 months and when they were III. FINDINGS: By the end of 1995, 93 prevalent cases and 86 incident cases had been enrolled. Four patients in the prevalent group were in stage 4 (AIDS) at the initial visit. During the next 5 years, 37 prevalent cases progressed to AIDS. Seven incident cases progressed to AIDS and the cumulative progression to AIDS at 1, 3, and 5 years after seroconversion was 2%, 6%, and 22%, respectively. The cumulative probability of AIDS at 4 years from entering stages 1, 2, and 3 was 11%, 33%, and 58%, respectively. There were 47 deaths among prevalent cases and seven among incident cases during follow-up. The cumulative mortality 4 years after patients entered stages 1, 2, 3, and 4 was 9%, 33%, 56%, and 86%, respectively. The median survival after the onset of AIDS was 9.3 months. INTERPRETATION: Our results are important for the setting of priorities and rationalisation of treatment availability in countries with poor resources. We found that progression rates to AIDS are similar to those in developed countries for homosexual cohorts and greater than for cohorts infected by other modes of transmission. However, we have found that the rates of all-cause mortality are much higher and the progression times to death are shorter than in developed countries.  相似文献   
259.
To reliably identify the residual tetracycline antibiotics (TCs), oxytetracycline (OTC), tetracycline, chlortetracycline (CTC) and doxycycline (DC), in bovine tissues, we have established a confirmation method using electrospray ionization liquid chromatography-tandem mass spectrometry (ESI LC-MS-MS) with daughter ion scan. All TCs gave [M+H-NH3]+ and [M+H-NH3-H2O]+ as the product ions, except for DC when [M+H]+ was selected as the precursor ion. The combination of C18 cartridge clean-up and the present ESI LC-MS-MS method can reliably identify TCs fortified at a concentration of 0.1 ppm in bovine tissues, including liver, kidney and muscle, and has been successfully applied to the identification of residual OTC in bovine liver and residual CTC in bovine muscle samples previously found at concentrations of 0.58 ppm and 0.38 ppm by LC, respectively.  相似文献   
260.
We have reviewed 75 amputees, 58 in the lower limb and 18 in the upper. Closed amputation was performed in 69 patients (92%) and an open procedure in six (8%). Wound infection occurred in six (8%) and one patient died from thromboembolism. Wound healing was normal in the remainder. The results of closed amputation in war conditions are very good, if performed within 6 hours of injury.  相似文献   
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