The decline in US teen pregnancy rates, 1990-1995

OBJECTIVES: Estimate pregnancy, abortion, and birth rates for 1990 to 1995 for all teens, sexually experienced teens, and sexually active teens. DESISN: Retrospective analysis of national data on pregnancies, abortions, and births. Participants. US women aged 15 to 19 years. OUTCOME MEASURES: Annual pregnancy, abortion, and birth rates for 1990 to 1995 for women aged 15 to 19 years, with and without adjustments for sexual experience (ever had intercourse), and sexual activity (had intercourse within last 3 months). RESULTS: Approximately 40% of women aged 15 to 19 years were sexually active in 1995. Teen pregnancy rates were constant from 1990 to 1991. From 1991 to 1995, the annual pregnancy rate for women aged 15 to 19 years decreased by 13% to 83.6 per 1000. The percentage of teen pregnancies that ended in induced abortions decreased yearly; thus, the abortion rate decreased more than the birth rate (21% vs 9%). From 1988 to 1995, the proportion of sexually experienced teens decreased nonsignificantly. CONCLUSIONS: After a 9% rise from 1985 to 1990, teen pregnancy rates reached a turning point in 1991 and are now declining. Physicians should counsel their adolescent patients about responsible sexual behavior, including abstinence and proper use of regular and emergency contraception.     

Measurement of fat digestion in early life using a stable isotope breath test

13C breath tests are a safe, non-invasive way of assessing nutrient digestion and absorption that can be used repeatedly in infancy and childhood. The aim of this study was to assess their value for measuring fat digestion in infants and young children with cystic fibrosis, and healthy controls whose pancreatic exocrine function is immature, and to monitor pancreatic enzyme supplementation. Six infants with cystic fibrosis (aged 10-18 months) and nine healthy controls (aged 6-19 months) were studied. After an overnight fast each child ingested 7.5 mg/kg 13C trioctanoin (99 atom % excess) followed by a known volume of milk. Breath samples were collected before and at 30 minute intervals thereafter for five hours. The 13C enrichment of expired carbon dioxide was measured by gas isotope ratio mass spectrometry. The mean (SD) percentage dose recovery of 13C was 13.5 (5.3) for the cystic fibrosis group and 24.2 (6.7) for the healthy controls. When those with cystic fibrosis were studied after supplementary pancreatic enzymes, the mean percentage dose recovery rose to 17.1 (6.9). Total intraluminal lipolysis was diminished by 44% in young children with cystic fibrosis. Pancreatic enzyme supplements improved digestion by 27%. The 13C trioctanoin breath test was effective in detecting fat maldigestion and can be used to measure the benefits of enzyme supplements in early life.     

蒙医诊断学教学探讨

蒙医诊断学是具有较强理论性和实践性的学科，这一特点要求我们在蒙医诊断学的教学方法上，既要重视理论教学，又要重视临床教学；既要传授知识，又要培养实际动手能力。     

Characterization of novel Mycobacterium tuberculosis pncA gene mutations in clinical isolates from the Ukraine

Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis cases in the Ukraine are increasing. Pyrazinamide (PZA) is critically important for first- and second-line tuberculosis (TB) treatment regimes. However, PZA drug susceptibility testing is time consuming and technically challenging. The present study utilized Next-generation sequencing (NGS) to identify mutations in the pncA gene from clinical isolates and to assess the prevalence of pncA gene mutations in MDR/XDR-TB patients. Clinical isolates were inactivated in molecular transport media and shipped from Kharkiv, Ukraine, to San Antonio, TX. Whole-genome and targeted pncA gene sequencing was carried out using Illumina MiSeq instrumentation. Mutations were noted in 67 of 91 (74%) clinical isolates comprising substitutions, insertions, and deletions in the pncA coding and upstream promoter region. Of 45 mutation types, there were 11 novel, i.e., to date unknown, pncA mutations identified of which 3 were confirmed PZA resistant. Seven isolates contained mixed base mutations, whereas 4 harbored doubled mutations. Data reported here further support use of NGS for pncA gene characterization and may contribute in significant fashion to PZA therapy, especially in MDR- and XDR-TB patients.     

Acute normovolemic hemodilution is a cost-effective alternative to preoperative autologous blood donation by patients undergoing radical retropubic prostatectomy

BACKGROUND: Preoperative autologous blood donation is accepted as a standard of care for radical prostatectomy. Acute normovolemic hemodilution (ANH) is an alternative method for obtaining autologous blood. The cost and benefits of these two autologous blood-collection techniques are compared. STUDY DESIGN AND METHODS: Thirty consecutive patients scheduled for radical prostatectomy underwent ANH to a target hematocrit level of 28 percent. Blood was transfused in the perioperative period to maintain the hematocrit level > 25 percent. Hematocrit levels, transfusion outcomes and costs, and postoperative outcomes for these patients (hemodilution group) were compared with a matched patient cohort who preoperatively donated 3 units of blood for autologous use in prostatectomy surgery (nonhemodilution group, n = 30). RESULTS: Thirty patients underwent ANH to a hematocrit level of 28.7 +/− 1.7 percent, and 1740 +/− 346 mL (3.5 +/− 0.7 units) of blood were collected. Three (10%) of the patients in each cohort had allogeneic blood exposure. Transfusion costs were 73 percent higher for the nonhemodilution group patients than for the hemodilution group patients ($330 +/− $100 vs. $191 +/− $55, p < 0.001). No differences were found in postoperative outcomes. CONCLUSION: An integrated blood conservation program utilizing hemodilution and a defined transfusion trigger can decrease the requirement for preoperative donation of blood for autologous use in radical prostatectomy. Point-of-care autologous blood procurement is more cost-effective than preadmission donation of autologous blood units.     

Receptor tyrosine kinase stimulates cell-matrix adhesion by phosphatidylinositol 3 kinase and phospholipase C-gamma 1 pathways

Receptor tyrosine kinases are known to be important in growth and differentiation. We have recently found that c-kit, the tyrosine kinase receptor for steel factor, also regulates cell-matrix adhesion. Because Steel factor helps regulate cell migration and localization, this may be an important biologic function. Integrin adhesiveness is regulated within minutes by c-kit. The signaling pathways for tyrosine kinase stimulation of integrin adhesiveness and their relation to pathways that regulate growth and differentiation over much longer time periods remain uncharacterized. We have studied the effector pathways by which receptor tyrosine kinases regulate cell-matrix adhesion using wild-type and mutant forms of the platelet-derived growth factor (PDGF) receptor, which is closely related to c-kit. The PDGF receptor expressed in mast cells is as potent as c-kit in stimulating adhesion to fibronectin. We show that induction of adhesion is regulated through two independent pathways of phosphatidylinositol 3 kinase (PI3K) and phospholipase C- gamma 1 (PLC gamma)-protein kinase C by elimination of autophosphorylation sites required for activation of PI3K and PLC gamma or in combination with downregulation of protein kinase C or wortmannin. By contrast, a receptor mutated in both the PI3K and PLC gamma association sites can still stimulate mast cell growth, indicating a crucial role of these effector molecules in regulating adhesion rather than cell growth.     

PHYSICAL HEALTH OF TEN-YEAR-OLD CHILDREN An Epidemiological Study of School Children and a Follow-up of Previous Health Care

ABSTRACT. At 10 years of age, all 223 children in a school district underwent a physical examination and a screening for vision and hearing defects within the school health services. The purpose of the study was to detect health problems of importance for the day-to-day functioning of the child. In 26.1% significant deviations were found. Physical disorders comprised 11.7%, visual defects 11.7% and auditory impairment 2.7%. The vast majority of significant health problems were previously known and in only 4.4% of the 223 children newly detected, 0.9% by the physical examination, 2.7% by the vision screening and 0.9% by the auditory screening. The most frequent health problem of all was allergy in 13.5%, in 5.4% regarded as functionally important. Minor orthopaedic deviations and motor disturbances were common but not often considered to affect the functioning of the child significantly. As a whole, the children's health was very good and the outcome of the physical examination at this age was not impressive. It is evident that the physician's role in the school health system needs to be reconsidered.