Evaluation of practice change following SAFE obstetric courses in Tanzania: a prospective cohort study.

Anaesthesia has been shown to contribute disproportionately to maternal mortality in low-resource settings. This figure exceeds 500 per 100,000 live births in Tanzania, where anaesthesia is mainly provided by non-physician anaesthetists, many of whom are working as independent practitioners in rural areas without any support or opportunity for continuous medical education. The three-day Safer Anaesthesia from Education (SAFE) course was developed to address this gap by providing in-service training in obstetric anaesthesia to improve patient safety. Two obstetric SAFE courses with refresher training were delivered to 75 non-physician anaesthetists in the Mbeya region of Tanzania between August 2019 and July 2020. To evaluate translation of knowledge into practice, we conducted direct observation of the SAFE obstetric participants at their workplace in five facilities using a binary checklist of expected behaviours, to assess the peri-operative management of patients undergoing caesarean deliveries. The observations were conducted over a 2-week period at pre, immediately post, 6-month and 12-month post-SAFE obstetric training. A total of 320 cases completed by 35 participants were observed. Significant improvements in behaviours, sustained at 12 months after training included: pre-operative assessment of patients (32% (pre-training) to 88% (12 months after training), p < 0.001); checking for functioning suction (73% to 85%, p = 0.003); using aseptic spinal technique (67% to 100%, p < 0.001); timely administration of prophylactic antibiotics (66% to 95%, p < 0.001); and checking spinal block adequacy (32% to 71%, p < 0.001). Our study has demonstrated positive sustained changes in the clinical practice amongst non-physician anaesthetists as a result of SAFE obstetric training. The findings can be used to guide development of a checklist specific for anaesthesia for caesarean section to improve the quality of care for patients in low-resource settings.

Five-year retrospective review of ultrasound-guided manual vacuum aspiration for first-trimester miscarriage.

INTRODUCTION: Manual vacuum aspiration is increasingly accepted as an alternative to medical or surgical evacuation of the uterus after first-trimester miscarriage. This study aimed to assess the efficacy of ultrasound-guided manual vacuum aspiration (USG-MVA) in the management of first-trimester miscarriage. METHODS: This retrospective analysis included adult women with first-trimester miscarriage who underwent USG-MVA in Hong Kong between July 2015 and February 2021. The primary outcome was the efficacy of USG-MVA in terms of complete evacuation of the uterus, without the need for further medical or surgical intervention. Secondary outcomes included tolerance of the entire procedure, the success rate of karyotyping using chorionic villi, and procedural safety (ie, any clinically significant complications). RESULTS: In total, 331 patients were scheduled to undergo USG-MVA for first-trimester miscarriage or incomplete miscarriage. The procedure was completed in 314 patients and well-tolerated in all of those patients. The complete evacuation rate was 94.6% (297/314), which is similar to the rate (98.1%) achieved by conventional surgical evacuation in a previous randomised controlled trial in our unit. There were no major complications. Samples from 95.2% of patients were suitable for karyotyping, which is considerably higher than the rate of suitable samples (82.9%) obtained via conventional surgical evacuation in our previous randomised controlled trial. CONCLUSION: Ultrasound-guided manual vacuum aspiration is a safe and effective method to manage first-trimester miscarriage. Although it currently is not extensively used in Hong Kong, its broader clinical application could avoid general anaesthesia and shorten hospital stay.

Implementation of ovarian tissue cryopreservation in Hong Kong.

INTRODUCTION: Worldwide, >130 babies have been born from ovarian tissue cryopreservation (OTC) and ovarian tissue transplantation (OTT). Ovarian tissue cryopreservation can improve quality of life among young female cancer survivors. Here, we assessed the feasibility of OTC and subsequent OTT in Hong Kong via xenografts in nude mice. METHODS: This pilot study was conducted in a university-affiliated tertiary hospital. Fifty-two ovarian tissues were collected from 12 patients aged 29 to 41 years during ovarian surgery, then engrafted into 34 nude mice. The efficacies of slow freezing and vitrification were directly compared. In Phase I, non-ovariectomised nude mice underwent ovarian tissue engraftment. In Phase II, ovariectomised nude mice underwent ovarian tissue engraftment, followed by gonadotrophin administration to promote folliculogenesis. Ovarian tissue viability was assessed by gross anatomical, histological, and immunohistochemical examinations before and after OTC. Follicular density and morphological integrity were also assessed. RESULTS: After OTC and OTT, grafted ovarian tissues remained viable in nude mice. Primordial follicles were observed in thawed and grafted ovarian tissues, indicating that the cryopreservation and transplantation protocols were both effective. The results were unaffected by gonadotrophin stimulation. CONCLUSION: This study demonstrated the feasibility of OTC in Hong Kong as well as primordial follicle viability after OTC and OTT in nude mice. Ovarian tissue cryopreservation is ideal for patients who cannot undergo the ovarian stimulation necessary for oocyte or embryo freezing as well as prepubertal girls (all ineligible for oocyte freezing). Our findings support the clinical implementation of OTC and subsequent OTT in Hong Kong.

Cross-border reproductive care use by women with infertility in Hong Kong: cross-sectional survey.

OBJECTIVES: Cross-border reproductive care (CBRC) is an increasingly common global phenomenon, but there is a lack of information regarding its frequency among residents of Hong Kong. This study aimed to evaluate the use of CBRC and the factors affecting its use among residents of Hong Kong. METHODS: This cross-sectional questionnaire study collected data from 1204 women with infertility who attended Hong Kong Hospital Authority and Family Planning Association infertility clinics. RESULTS: In total, 178 women (14.8% of all respondents) had used CBRC. Among respondents who had not used CBRC, 36.3% planned to use or would consider it. The main factors influencing the likelihood of using CBRC among women with infertility in Hong Kong use were long waiting times in the public sector and high cost in the private sector. Taiwan was the most preferred destination for CBRC (69.6% of respondents). Most information concerning CBRC was accessed via the internet. More than two thirds of respondents believed that the government in Hong Kong should formulate some regulations or guidance regarding CBRC. CONCLUSION: Nearly one in six women with infertility in Hong Kong had used CBRC. Among women who had not used CBRC, more than one third planned to use or would consider it. The main factors influencing the likelihood of CBRC use were long waiting times in the public sector and high cost in the private sector. These results will help clinicians to more effectively counsel patients considering CBRC and facilitate infertility services planning by authorities in Hong Kong.

Outcomes after oesophageal perforation: a retrospective cohort study of patients with different aetiologies.

INTRODUCTION: The mortality rate after oesophageal perforation is high despite advances in operative and non-operative techniques. In this study, we sought to identify risk factors for hospital mortality after oesophageal perforation treatment. METHODS: We retrospectively examined patients treated for oesophageal perforation in a university teaching hospital in Hong Kong between January 1997 and December 2013. Their demographic and clinical characteristics, aetiology, management strategies, and outcomes were recorded and analysed. RESULTS: We identified a cohort of 43 patients treated for perforation of the oesophagus (28 men; median age, 66 years; age range, 30-98 years). Perforation was spontaneous in 22 (51.2%) patients (15 with Boerhaave's syndrome and seven with malignant perforation), iatrogenic in 15 (34.9%), and provoked by foreign body ingestion in six (14.0%). Of the patients, 14 (32.6%) had pre-existing oesophageal disease. Perforation occurred in the intrathoracic oesophagus in 30 (69.8%) patients. Emergent surgery was undertaken in 23 patients: 16 underwent primary repair, six surgical drainage or exclusion, and one oesophagectomy. Twenty patients were managed non-operatively, 13 of whom underwent stenting. Two stented patients subsequently required oesophagectomy. Four patients had clinical signs of leak after primary repair: two were treated conservatively and two required oesophagectomy. Overall, six (14.0%) patients required oesophagectomy, one of whom died. Nine other patients also died in hospital; the hospital mortality rate was 23.3%. Pre-existing pulmonary and hepatic disease, and perforation associated with malignancy were significantly associated with hospital mortality (P=0.03, <0.01, and <0.01, respectively). CONCLUSIONS: Most oesophageal perforations were spontaneous. Mortality was substantial despite modern therapies. Presence of pre-existing pulmonary disease, hepatic disease, and perforation associated with malignancy were significantly associated with hospital mortality. Salvage oesophagectomy was successful in selected patients.

Spontaneous circumferential intramural esophageal dissection complicated with esophageal perforation and esophageal-pleural fistula: a case report and literature review.

Spontaneous intramural esophageal dissection (IED) is a rare disease entity. There are few reports of spontaneous IED requiring surgical treatment. Hereby, we report a 37-year-old gentleman who was diagnosed to have spontaneous extensive circumferential IED complicated with esophageal perforation, empyema, and esophageal-pleural fistula. Esophageal stenting and drainage of empyema were unsuccessful. Computed tomography and gastrografin contrast swallow demonstrated a leak to the pleural cavity, suggestive of esophageal-pleural fistula. Subsequently, a two-stage operation was performed: cervical esophagogastrostomy to bypass the perforated esophagus, followed by esophagectomy and decortication of the right lung. The patient recovered and was discharged home after a 3-week hospitalization. The management principles and recent published literature related to IED were reviewed.

Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma: magnifying endoscopy findings.

Gastric mucosa-associated lymphoid tissue lymphoma is uncommon and most patients have an indolent clinical course. The clinical presentation and endoscopic findings can be subtle and diagnosis can be missed on white light endoscopy. Magnifying endoscopy may help identify the abnormal microstructural and microvascular patterns, and target biopsies can be performed. We describe herein the case of a 64-year-old woman with Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma diagnosed by screening magnification endoscopy. Helicobacter pylori-eradication therapy was given and she received biological therapy. She is in clinical remission after treatment. The use of magnification endoscopy in gastric mucosa-associated lymphoid tissue lymphoma and its management are reviewed.

Incidental thyroid carcinoma by FDG-PET/CT: a study of clinicopathological characteristics.

BACKGROUND: The rising incidence of incidental thyroid carcinoma (ITC) detected during fluoro-2-deoxy-D: -glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) scanning poses a challenge to clinicians. The present study aims to critically evaluate the clinicopathological characteristics of ITC detected by FDG-PET/CT. METHODS: Among the 557 patients managed at our institution, 40 (7.2%) patients were identified as having ITC. Of these, 22 patients had their tumor detected by FDG-PET/CT (PET group) and 11 by ultrasonography (USG group). Additional bedside ultrasonography ± fine-needle aspiration (FNA) was done in all patients at their clinic visit. The clinicopathological characteristics were compared between the PET and USG groups. RESULTS: The PET group had significantly more patients with history of nonthyroidal malignancy (P < 0.001). Papillary carcinoma was the most common histological type in both groups. Despite having similar histological and prognostic features including tumor size, tumor multifocality, capsular invasion, extrathyroidal extension, and lymph node metastases, tumor bilaterality (or presence of contralateral tumor focus) was significantly more frequent in the PET than the USG group (P = 0.04). The tumors were also more advanced by the tumor-node-metastasis (TNM) staging system in the PET group (P = 0.021). None of the contralateral tumor foci were evident preoperatively. One patient in the USG group developed metastatic thyroid carcinoma in neck lymph nodes 28 months after thyroid resection. CONCLUSION: ITC by FDG-PET/CT had higher incidence of tumor bilaterality than those detected by ultrasonography. Total thyroidectomy should be considered for ITC detected by FDG-PET/CT even for tumor size <10 mm.

Secondary prevention of stroke: an evidence-based clinical audit in the primary care.

OBJECTIVE: To audit secondary preventive care in non-acute stroke patients in a local General Outpatient Clinic of the Hospital Authority. DESIGN: Comparison of two samples from a case series at different time-points. SETTING: General Outpatient Clinic, Hong Kong. PATIENTS: Non-acute stroke patients fulfilling the inclusion criteria and regularly followed up in a local General Outpatient Clinic during the audit cycle were recruited. Evidence-based audit criteria and performance standards were established after thorough literature review. A sample from this case series was compared retrospectively at two time-points. First-phase evaluation was performed in October 2009 and deficiencies were identified. After 9 months of active intervention, second-phase evaluation was performed in July 2010. Chi squared test and student's t test were used to compare the significance of relevant changes noted. RESULTS: First-phase data showed marked deficiencies in proper assessment of cardiovascular risk factors. Satisfactory blood pressure, glucose and lipid control was evident only in 47% of the hypertensive, 45% of the diabetic, and 37% of the dyslipidaemic stroke patients, respectively. After 9 months of implementing changes, significant improvements were noted with respect to standard targets being achieved. In the second phase, more comprehensive tackling of cardiovascular risk factors was noted, with satisfactory blood pressure control in 73% of hypertensive patients, and adequate metabolic control in 62% diabetic patients (P<0.01 for both). Only 59% of the dyslipidaemic stroke patients had optimal lipid control, though their mean low-density lipoprotein concentration was significantly reduced (P<0.05). CONCLUSION: This study provided a valuable lesson in identifying deficiencies in secondary prevention for stroke patients managed in a local primary care facility. Using a team approach intervention, quality assurance was promoted and a definite impact on patient care was demonstrated.

Effects of Three Different Exercise Strategies for Optimizing Aerobic Capacity and Skeletal Muscle Performance in Older Adults: A Pilot Study.

This Brief Report describes a pilot study of the effect of 12 weeks of stationary bicycle high-intensity interval training, stationary bicycle moderate-intensity continuous training, and resistance training on cardiorespiratory, muscular, and physical function measures in insufficiently-active older adults (N=14; 66.4±3.9 years; 3 male, 11 female). After baseline testing, participants were randomly assigned to one of the exercise groups. High-intensity interval training and moderate-intensity continuous training had small-to-large effect sizes on cardiorespiratory/endurance and physical function measures, but very small effect sizes on muscular measures. Resistance training had small-to-large effect sizes on cardiorespiratory, muscular, and physical function measures. This pilot study should be interpreted cautiously, but findings suggest that resistance exercise may be the most effective of the three studied exercise strategies for older adults as it can induce beneficial adaptations across multiple domains. These effect sizes can be used to determine optimal sample sizes for future investigations.

Fetal antigens on the surface of human lymphoid cells.

Human B-lymphoblastoid cells established in long-term culture from healthy adults carry surface components that are normally found in human fetal tissues at about 10 wk of age. These antigens are strongly expressed on neoplastic B lymphocytes but not on thymocytes or a cultured T-cell line. They are carried by a small subpopulation of normal adult peripheral blood lymphocytes as well.

Telephone pre-anaesthesia assessment for ambulatory breast surgery.

OBJECTIVE: To review the efficacy of telephone preoperative anaesthesia assessment in patients undergoing ambulatory breast surgery. DESIGN: Retrospective study. SETTING: Day Surgery Centre, Tung Wah Hospital, Hong Kong. PATIENTS: Patients with breast lumps to be excised were seen by dedicated breast surgeons and informed of day procedures and preoperative anaesthesia assessment. Those who fulfilled the selection criteria of age (18-45 years) and American Society of Anesthesiologists grade I were recruited for telephone anaesthesia assessment preoperatively. The patients were contacted by senior day surgery nurses via telephone before the scheduled operation date, and information was retrieved using a standard assessment form. Prospective data from January 2002 to December 2007 were analysed. MAIN OUTCOME MEASURES: Proportion of patients who successfully underwent day surgery after telephone preoperative anaesthesia assessment. RESULTS: Of 482 patients receiving ambulatory surgery for breast lumps during the study period, 283 patients were selected for preoperative telephone anaesthesia assessment. Five (2%) patients with problems identified by this method underwent further assessment at the Day Surgery Centre; the remaining 278 (98%) required no further assessment and proceeded to have a successful day surgery procedure. CONCLUSION: Preoperative anaesthesia assessment by telephone is an effective means of preoperative assessment in selected patients undergoing ambulatory breast surgery.

Analysis and comparison of cumulative antibiograms for the Charlotte Maxeke Johannesburg Academic Hospital adult intensive care and high-care units, 2013 and 2017.

BACKGROUND: Infection is a common complication for patients in intensive care units (ICUs), and increasing antimicrobial resistance (AMR) is a major concern. It is therefore crucial to monitor AMR patterns in order to support clinical decision-making and antimicrobial stewardship strategies. Clinical microbiologists should provide annual cumulative antibiogram reports, which can be used to guide initial empirical antimicrobial therapy for the management of infections. OBJECTIVES: To analyse the cumulative antibiograms for the Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) combined adult multidisciplinary ICU and high-care unit (HCU) for 2013 and 2017, compare the antimicrobial susceptibility testing (AST) patterns between the 2 years, and analyse the subset of blood culture isolates. METHODS: A retrospective descriptive analysis was performed of routine bacterial and fungal culture and AST data extracted from the National Health Laboratory Service laboratory information system for the ICU/HCU. Only the first diagnostic isolate of a given species per patient per year was included in the analysis. All analysis and reporting were done in accordance with the applicable Clinical and Laboratory Standards Institute guidelines. RESULTS: Enterobacteriaceae predominated in first-isolate cultures in 2013 (60%) and 2017 (56%). There was an overall decrease in extended-spectrum beta-lactamase-producing Enterobacteriaceae from 2013 (42%) to 2017 (30%) (p=0.013), accompanied by an increase in carbapenem-resistant Enterobacteriaceae from 2013 (4%) to 2017 (11%) (p=0.24). Although the total percentage of Acinetobacter spp. decreased in 2017 (p=0.021), the proportion of extensively drug-resistant isolates doubled to 68% in 2017 (p<0.001). The percentage of methicillin-resistant Staphylococcus aureus decreased significantly from 49% to 14% (p<0.001), along with a significant decrease in vancomycin-resistant enterococci from 17% to 0% (p=0.001). Candida auris increased from 0% in 2013 to 11% in 2017 (p=0.002), and non-albicans Candida spp. predominated (80%) in blood cultures in 2017 (p=0.023). CONCLUSIONS: Appropriate selection of empirical antimicrobial therapy should be guided by the ICU-specific antibiogram. The recommended empirical antimicrobial therapy at the CMJAH ICU/HCU based on the antibiogram analysis would include ertapenem to cover the Enterobacteriaceae. Amikacin is recommended for empirical treatment of suspected pseudomonal infections. Additional empirical antimicrobial therapy for Gram-positive organisms is not routinely advocated, and empirical antifungal therapy with amphotericin B or micafungin is only appropriate in patients at high risk for invasive candidiasis.

Prevalence of smoking and drinking habits among Form Six students in Petaling District, Selangor.

Smoking and alcohol intake patterns may persist from adolescence to adulthood. The aims of this study are to determine the prevalence and factors associated with smoking and drinking habits among Form Six students. This was a cross-sectional study conducted in January 2003 among Form Six students from government schools in the Petaling District, Selangor. A hundred and thirty six self-administered questionnaires were distributed to students selected through multistage stratified sampling. Response rate in this study was 90.1% (136/151). The respondents were mainly Chinese 60 (44.1%) and female 88 (64.7%). The prevalence of smoking was 22.8%, whereas the prevalence of alcohol intake was 47.8%. Only 33.1% of the respondents practiced undetermined activities and 1.5% have undetermined characters. There were significant associations between smoking and males (Adjusted OR 2.56, 95% CI 1.02-6.43) and smoking and alcohol intake (Adjusted OR 2.74, 95% CI 1.11-6.78). Alcohol intake has significant negative association with Malays (Adjusted OR 0.83, 95% CI 0.03-0.27). Smoking habits among adolescents were associated with males and alcohol intake. However, only alcohol intake was negatively associated with Malays. Program interventions to reduce behavioral problems, particularly smoking and alcohol intake should be emphasized.

Fetal antigens in nonneoplastic conditions.

During studies that showed the presence of fetal antigens on the surface of human malignant melanoma tumor cells, polyvalent antisera specific for human fetal tissues of varying ages were developed. These reagents demonstrated varying patterns of expression of fetal antigens at different ages in various tissues of the human fetus. The possibility that nonneoplastic adult cells showing either maturation arrest or excessive proliferation also might express fetal antigens led to studies of human bone marrow. Although normal bone marrow cells expressed low levels of fetal antigens, large amounts were seen on bone marrow cells of patients with anemias due to iron, B12, or folic acid deficiencies, as well as on those with leukemia. Moreover, normal adult tissues adapted to long-term culture also expressed fetal antigens. After 3 weeks in organ culture adult human skin showed morphological changes similar to those seen in fetal periderm and strongly expressed fetal antigens. In addition, lymphoblasts in long-term cultured human lymphoid cell lines established from normal donors also carried surface fetal antigens. These latter antigens were shared with neoplastic B-cells (chronic lymphocytic leukemia) but not with T-cells. Their expression varied with the cell cycle. The reexpression of fetal antigens on malignant cells is thought to signal a basic derangement in the control of differentiation which is considered to be peculiar to neoplasia. However, these studies indicate that normal adult cells also may reexpress fetal antigens under circumstances unrelated to neoplasia but associated with either maturation arrest or rapid and excessive proliferation.

Emergence of Carbapenem-Resistant Acinetobacter baumannii in Nursing Homes With High Background Rates of MRSA Colonization.

Carbapenem-resistant Acinetobacter baumannii (CRAB) with diverse multilocus sequence typing emerged among our nursing home residents (6.5%) with a high background rate of MRSA (32.2%). Rectal swabs yielded a higher rate of CRAB detection than axillary or nasal swabs. Bed-bound status, use of adult diapers, and nasogastric tube were risk factors for CRAB colonization. Infect Control Hosp Epidemiol 2016;37:983-986.

Interferon alfa-2a and 13-cis-retinoic acid in renal cell carcinoma: antitumor activity in a phase II trial and interactions in vitro.

PURPOSE: A phase II trial of interferon alfa-2a (IFN) and 13-cis-retinoic acid (CRA) was conducted in patients with renal cell carcinoma (RCC). In vitro studies were performed to investigate potential mechanisms of interaction. PATIENTS AND METHODS: Forty-four patients were treated. IFN was given daily at 3 MU and escalated to 6 and 9 MU if tolerated. The dose of CRA was 1 mg/kg/d. The effects of combining CRA and IFN on the proliferation of five RCC cell lines were examined, and retinoid sensitivity was correlated to the expression of retinoic acid receptors. RESULTS: Thirteen (30%) of 43 assessable patients achieved a major response (three complete and 10 partial). Responding sites included bone metastases and renal primary tumors. Seven responding patients remain progression-free at 10+ to 19+ months. The response proportion was higher than in our prior experience with IFN, which was 10% in 149 patients. Eleven of 12 renal cancer cell lines were resistant to CRA alone; one, SK-RC-06, showed 90% inhibition of cell growth. CRA augmented the antiproliferative effect of IFN in several IFN-sensitive cell lines, but not in IFN-resistant lines. Northern blot analysis showed that expression of retinoic acid receptor-beta (RAR-beta) was repressed and not induced by retinoic acid in retinoic acid-insensitive RCC lines. However, RAR-beta expression was induced by retinoic acid in SK-RC-06 cells. CONCLUSION: IFN and CRA showed antitumor activity in patients with advanced RCC, and the proportion and nature of response suggested CRA added therapeutic benefit to IFN. A phase III randomized trial of IFN plus CRA versus IFN alone and a phase II trial of single-agent CRA have been initiated.

Preliminary cryocrystallographic study of the mitochondrial cytochrome bc1 complex: improved crystallization and flash-cooling of a large membrane protein.

Ubiquinol-cytochrome c reductase is a crucial integral membrane protein in the mitochondrial respiratory cycle. Eleven subunits containing three cytochrome heme groups and a 2Fe-2S Rieske center make up this 240 kDa enzyme complex. Previously, many different crystal forms of the bc1 complex have displayed diffraction to as far as 4.5 A. However, rapid degradation of the protein in the X-ray beam at room temperature has obstructed the collection of a full data set from a single crystal. As slight heterogeneities between crystals severely hampered merging of data from different crystals, we sought a method to stabilize the protein crystal in the X-ray beam in order to collect a full data set from one crystal sample. To this end, water soluble protein crystals are frequently flash-cooled to cryogenic temperatures; however, there is no report of cryocrystallography for membrane proteins. In this communication, we report on a successful experiment in which flash-cooled bc1 membrane protein crystals have given rise to sustained diffraction over a 60 hour data collection period at a synchrotron source. Furthermore, we present an improved purification and crystallization protocol yielding crystals readily diffracting out to 3.3 A. These results should greatly aid in the future realization of the molecular structure of the bc1 complex as well as other membrane proteins.

Genetic questions for environmental studies. Differential parenting and psychopathology in adolescence.

BACKGROUND: Recent genetic evidence suggests that the most important environmental influences on normal and pathologic development are those that are not shared by siblings in the same family. We sought to determine the relationship between differences in parenting styles and depressive symptoms and antisocial behavior in adolescence, and to compare the influence of these nonshared experiences with genetic influences. METHODS: We studied 708 families with at least two same-sexed adolescent siblings who were monozygotic twins (93 families), dizygotic twins (99 families), ordinary siblings (95 families), full siblings in step families (181 families), half siblings in step families (110 families), and genetically unrelated siblings in step families (130 families). Data on parenting style were collected by questionnaire and by video recording of interaction between parents and children. RESULTS: Almost 60% of variance in adolescent antisocial behavior and 37% of variance in depressive symptoms could be accounted for by conflictual and negative parental behavior directed specifically at the adolescent. In contrast, when a parent directed harsh, aggressive, explosive, and inconsistent parenting toward the sibling, we found less psychopathologic outcome in the adolescent. CONCLUSIONS: Parenting behavior directed specifically at each child in the family is a major correlate of symptoms in adolescents. Furthermore, harsh parental behavior directed at a sibling may have protective effects for adolescents, a phenomenon we call the "siblin barricade."