年龄及人参皂甙 Rg1 对大鼠大脑皮层 NO 释放的影响

探讨了NO与衰老的关系及与Rg1抗衰老机制的关系。用Griess法,³H-L-精氨酸转化法分别研究大鼠大脑皮层细胞NO含量及NOS活性,观察其随龄变化及人参皂甙Rg1(Rg1)对老年鼠NO及NOS的影响。实验表明,成年鼠(9月龄)与青年鼠(3月龄)NO含量及NOS活性无显著性差异。老年鼠(27月龄)脑皮层NO含量明显高于青年鼠和成年鼠,NOS活性也明显增高。老年鼠给予Rg1后可显著减少大脑皮层NO含量和降低NOS活性。结果提示,NO与衰老关系密切,Rg1的抗衰老作用与其对NOS活性的抑制有关。     

Unintended pregnancies in women delivering at 18 South American hospitals. NFP-ECLAMC Group. Latin American Collaborative Study of Congenital Malformations

Unintended pregnancies are accepted as associated with social, maternal and perinatal risks, but few data exist in South America. In a selected network of hospitals participating in the ECLAMC (Spanish acronym for Latin American Collaborative Study of Congenital Malformations), the frequency of unintended pregnancies was 49.8% in 5155 mothers of normal liveborns, as interviewed in the post-partum period (1992-1994). Compared with the intended pregnancy group, these mothers were more frequently multiparous, conceived easily, had a surprisingly higher mean maternal age, lower educational level, and Black ancestors. The frequency of mistimed pregnancies was the highest among primiparae. No adverse perinatal outcome could be found with regard to low birthweight (< 2500 g), prematurity (< 37 weeks), and early neonatal death. The rates of Caesarean delivery, twinning and sex ratio were similar in intended and unintended groups. Logistic regression analysis showed that maternal education could be a confounding factor associated with other maternal variables. The rate of unintended pregnancies in the present study is significantly higher than that described for other regions. Knowledge of the characteristics of women experiencing unintended pregnancies would allow proper public health strategies.      

Image-guided pleural biopsies: indications, technique, and results in 23 patients

Twenty-six pleural biopsies were performed on 23 patients over a 3-year period. Twenty-three biopsies were performed guided with ultrasound; one, with computed tomography; and two, with fluoroscopy. Indications for an image-guided pleural biopsy were (a) pleural masses or thickening that were either not seen on chest radiographs or seen only on one view and (b) small or loculated pleural effusions of unknown cause with no mass seen. If only pleural fluid was present, reverse bevel needles were used for biopsy (n = 15). If a discrete pleural mass or thickening was seen with cross-sectional imaging, standard (16-20 gauge) biopsy needles were used (n = 11). In the 23 patients, biopsy results were true positive in ten (nine with malignancy, one with tuberculous pleurisy), true negative in ten (confirmed either at subsequent thoracotomy or clinical follow-up), and false negative in three. Complications were few, with a significant pneumothorax occurring in two patients (8.7%). Image-guided biopsy of small pleural lesions and small pleural effusions can be performed by the radiologist who understands the special needles and techniques involved.     

The outcome of ankylosing spondylitis: a study of 100 patients

The outcome was studied in 100 patients with adult-onset primary ankylosing spondylitis (AS). After a mean disease duration of 16 yr, 51.5% of the patients were employed in full-time work. Cessation of work occurred at a mean disease duration of 15.6 yr, and was significantly associated with female sex, low levels of education, acute anterior uveitis, 'bamboo spine' and the co-existence of non- rheumatic diseases. Functional outcome was studied by analysing activities of daily living, and revealed similar findings in males and females. Most of the loss of function occurred during the first 10 yr of disease, and correlated significantly with the occurrence of peripheral arthritis, spinal X-ray changes of AS and development of 'bamboo spine'. After > 20 yr of disease, > 80% of the patients still complained of daily pain and stiffness, and > 60% reported daily use of drugs.      

Breast disease: tissue characterization with Gd-DTPA enhancement profiles

Magnetic resonance (MR) imaging of the breast is currently of limited value because of lack of specificity. Enhanced MR imaging with gadolinium diethylenetriaminepentaacetic acid (DTPA) has been shown to be helpful in the further characterization of breast tissue. This prospective study attempted to differentiate benign and malignant breast disease with a dynamic enhancement technique. Bolus injection of Gd-DTPA and a short MR imaging time were used to examine 18 patients with a palpable breast mass. Construction of enhancement profiles helped effectively differentiate benign and malignant lesion (P less than .001). Dynamic MR imaging shows promise for the further characterization of breast tissue and, particularly, identification of breast carcinoma.     

Sphincter preservation in patients with low rectal cancer treated with radiation therapy with or without local excision or fulguration

Twenty-six patients with small cancers limited to the lower two-thirds of the rectum were treated with conservative surgery and radiation therapy (XRT). The selection factors for this approach were age, refusal of a permanent colostomy, or the high risk of local recurrence because of inadequate surgical margin or palpable residual tumor after local surgical treatment alone. In patients treated with local excision or fulguration followed by XRT, there was a 6% local failure rate (one in 17); in 16 of 17 patients receiving radiation doses above 4,500 cGy, the local control was complete for follow-up periods of 6 months to 7 years. In nine patients treated with XRT for residual tumor, local failure occurred in five (56%). The disease-free survival for those without residual tumor versus those with residual tumor was 88% and 44%, with median follow-up periods of 20 and 23 months, respectively. Serious late complications occurred only if total doses were greater than 6,300 cGy. Local excision combined with XRT proved to be a safe alternative to radical surgery in selected patients and resulted in excellent local control while allowing preservation of anal sphincter function.     

Gallbladder bile in cholecystitis: in vitro MR evaluation

Fifty-three samples of gallbladder bile were obtained at the time of cholecystectomy from patients with the clinical diagnosis of acute or chronic cholecystitis. Five bile samples from patients with clinically normal gallbladders also were obtained. Proton magnetic resonance (MR) relaxation times, protein content, and water content were determined for the bile samples, and the data were grouped according to pathologic diagnosis, which disclosed 11 cases of acute cholecystitis, 41 cases of chronic cholecystitis, and six normal gallbladders. There was no significant difference in the mean T1 and T2 values between the groups with acute and chronic cholecystitis. Patients with chronic cholecystitis were found to have more concentrated bile than those with acute cholecystitis. Protein content varied widely within both groups of patients. We conclude that T1 and T2 relaxation times do not reliably differentiate acute from chronic cholecystitis.