What makes a biostatistician?

Biostatisticians play an important role in medical research. They are co-responsible for an appropriate and efficient study design, they are involved in monitoring the study conduct, they plan and perform the data analysis, and they are involved in interpreting and publishing the results. However, how are the biostatisticians prepared for their tasks and responsibilities? Graduate programs in biostatistics are being offered, but some practicing biostatisticians completed their studies in a mathematical or epidemiological program, or obtained their degree in subject-specific fields (such as medicine or biology). Therefore, the expertise and the competencies can vary widely between the individual biostatisticians, also depending on the application field. In this article, focusing on European and US practices, we discuss the required professional expertise for the main areas of applications in the medical field as well as the necessary soft skill competencies of a biostatistician.     

Posttraumatic stress, depression, and health among older adults in primary care.

OBJECTIVE: The authors examined 1) rates of trauma and posttraumatic stress (PTS) in older adults in primary care; 2) factors related to more posttraumatic stress symptoms; and 3) the influence of posttraumatic stress and depression on health perceptions and negative health behaviors (i.e., suicidal ideation, smoking, and at-risk drinking). METHODS: As part of participation in a study at the Philadelphia VAMC and the University of Pennsylvania, a random subset (N = 2,718) of older adults (age > or = 65 years) with scheduled primary care visits were screened concerning demographics, the General Health Questionnaire-12, suicidal thoughts, alcohol consumption, cigarette smoking, perceived health status, PTS, and cognitive impairment. RESULTS: The rate of trauma in older adult primary care patients was high in both the VA (37%) and university-based clinics (24%). Many older adults reported interference from at least one of the three posttraumatic stress items assessed (VA, 18%; university-based primary care, 8%). In a model including demographic factors, higher PTS and depression were uniquely related to more negative health perceptions. In a model including demographic factors, both higher PTS and depression were uniquely related to higher likelihood of suicidal ideation. In contrast, PTS no longer contributed to a model of smoking once depression was included. Neither PTS nor depression significantly contributed to a model of at-risk drinking. CONCLUSIONS: Trauma and posttraumatic stress are frequent and significant problems for older adults in primary care. Both posttraumatic stress and depression are related to more negative health perceptions and higher likelihood of suicidal ideation.     

顺铂聚乳酸微球的药物释放特性及肝动脉栓塞研究

对顺铂聚乳酸微球进行了体外药物释放和家犬肝动脉栓塞研究。该微球粒径范围为50～200μm,平均粒径为115.76±35.94μm,顺铂含量为37.16%(W/W);体外药物释放机制符合Higuchi方程;肝动脉栓塞后8h,肝组织顺铂浓度高达21.55±12.18μg/g,明显高于肝动脉灌注顺铂组:3.16±0.09μg/g(P<0.05);肝动脉栓塞组的顺铂血浓峰值、各取血点浓度及曲线下面积AUC皆低于肝动脉灌注顺铂组。可望达到提高栓塞部位的药物疗效,降低全身毒副反应的作用。     

Primary tuberculous nasal polypi—A case report

Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed.     

Further evidence of dopamine transporter dysregulation in ADHD: a controlled PET imaging study using altropane.

BACKGROUND: The dopamine transporter (DAT) is known to be a key regulator of dopamine, and recent studies of genetics, treatment, and imaging have highlighted the role of DAT in attention-deficit/hyperactivity disorder (ADHD). The findings of in vivo neuroimaging of DAT in ADHD have been somewhat discrepant, however. METHOD: Dopamine transporter binding was measured using a highly selective ligand (C-11 altropane) and positron emission tomography (PET). The sample consisted of 47 well-characterized, treatment-na?ve, nonsmoking, non-comorbid adults with and without ADHD. Additionally, control subjects had few symptoms of ADHD. RESULTS: Results showed significantly increased DAT binding in the right caudate in adults with ADHD compared with matched control subjects without this disorder. CONCLUSIONS: These results confirm abnormal DAT binding in the striatum of adults with ADHD and provide further support that dysregulation of DAT may be an important component of the pathophysiology of ADHD.     

Differential induction of cytochrome P-450 by the enantiomers of trans-stilbene oxide

Optically pure (+)- and (-)-trans-stilbene oxide (TSO) enantiomers were administered to immature male Sprague-Dawley rats. (+)-TSO was the more potent inducer of liver microsomal cytochrome P-450-dependent monooxygenases. The greater potency of (+)-TSO may be explained on the basis of stereoselective metabolism since a far greater concentration of TSO was found in liver microsomes of (+)-TSO-treated rats. Furthermore, of the enzymes known to metabolize TSO, cytosolic epoxide hydrolase turned over the (-)-TSO enantiomer at a faster rate, consistent with the greater persistence of the (+)-enantiomer. Although this report is of chiral effects in potency of enzyme induction, stereoselective metabolism (i.e. disposition) rather than inherent structural characteristics (recognition) may be responsible for these effects.     

Delayed osteotomy but not fracture healing in pediatric osteogenesis imperfecta patients receiving pamidronate.

This study evaluated factors influencing fracture (n = 197) and osteotomy (n = 200) healing in children with moderate to severe OI. Pamidronate treatment was associated with delayed healing after osteotomy, but not after fracture. The data suggest that both pamidronate and mechanical factors influence bone healing in this cohort. INTRODUCTION: Intravenous pamidronate is widely used to treat children with moderate to severe osteogenesis imperfecta (OI). However, the effect of this treatment on bone healing is not well characterized. We therefore retrospectively analyzed the healing of lower limb fractures and osteotomies in children with moderate to severe OI, both before and after the start of pamidronate treatment. MATERIALS AND METHODS: Bone healing was evaluated on standard radiographs after 197 lower limb fractures (132 femur and 65 tibia) in 82 patients (age at fracture, 0.0-19.9 years) and 200 intramedullary rodding procedures in 79 patients (age at surgery, 1.2-19.8 years). Delayed healing was diagnosed when a fracture or osteotomy line was at least partially visible 12 months after the event. RESULTS: Delayed fracture healing was observed more frequently during than before pamidronate treatment. However, the effect of pamidronate was no longer significant when age differences were taken into account (odds ratio [OR], 1.76; 95% CI, 0.61-5.10). Better mobility status was a strong independent predictor of delayed healing after fractures that occurred during pamidronate treatment. After osteotomies, delayed healing was more frequent when pamidronate had been started before surgery (OR, 7.29; 95% CI, 2.62-20.3), and this effect persisted after adjustment for multiple confounders. During pamidronate treatment, older age (OR per year of age, 1.25; 95% CI, 1.06-1.47) and osteotomy of the tibia (OR, 3.51; 95% CI, 1.57-7.82) were independent predictors of delayed healing. CONCLUSIONS: This study suggests that pamidronate therapy is associated with delayed healing of osteotomy sites after intramedullary rodding procedures. Better mobility status, but not pamidronate treatment, seems to be predictive of delayed healing after fractures.     

Sudden infant death, Williams-Beuren-Syndrom oder beides?

SummaryThe Williams-Beuren syndrome is a genetic disorder caused by a deletion of the elastin gene mapped on chromosome 7 (7q11.23). This results in multi-organ malformation, mental retardation and generalised elastin arteriopathy, which can lead to cardiac and vascular complications and to sudden death. We present two cases in which a postmortem examination was initially carried out with the presumptive diagnosis of sudden infant death, but cardiac malformations and facial dysmorphisms were recognised that could confirm the diagnosis of Williams-Beuren syndrome. In both cases nearly the same pathological findings were seen in the heart and lungs by histological examination. We will discuss if these findings could have caused death and if they can confirm our presumptive diagnosis of a William-Beuren syndrome which could not be verified by a genetic investigation.     

Effects of instruction by practice assistants on inhaler technique and respiratory symptoms of patients. A controlled randomized videotaped intervention study

BACKGROUND: Many patients with asthma or chronic obstructive pulmonary diseaseuse their medication inhalers incorrectly. General practitioners,pharmacists and other health care providers do not always havethe opportunity to instruct patients in correct inhaler technique. OBJECTIVE: To find out whether the inhaler technique and respiratory symptomsof patients can be improved after instruction by practice assistants. METHODS: Single blind, randomized intervention study in which 48 patientswho had been using a dry powder inhaler for at least one monthtook part. Their inhaler technique was videotaped on two visitswith a two-week interval between visits. The inhaler techniqueon the videos was subsequently scored by two experts on ninecriteria. At both visits the patients completed a questionnaireabout their respiratory symptoms. After the first video, 25patients were randomly chosen to receive instruction from oneof six practice assistants who had followed a one evening courseabout inhaler instruction, and who had been issued an instruction-set. RESULTS: The patients who received instruction had a significantly greaterreduction in number of mistakes at the second visit than thepatients who did not (P = 0.01). The instructed patients alsoreported less dyspnoea at the second visit (P = 0.03). No effectof instruction was found on wheezing, cough and sputum production. CONCLUSION: The inhaler technique of patients can be improved significantlyby the instruction of patients by trained practice assistants,possibly resulting in less dyspnoea. Keywords. Administration-inhalation, obstructive lung diseases, airways symptoms, patient-education, general practice.     

In situ saphenous vein bypass grafts: angiographic evaluation and interventional repair of complications

In situ saphenous vein grafts are being used with increasing frequency for bypass procedures involving the femoral and popliteal arteries. Complications of these procedures include anastomotic stenoses and persistent arteriovenous fistulae that may result in failure of the graft. Balloon angioplasty and embolotherapy with detachable balloons were employed successfully in three or four recent cases of patients with complications from in situ grafts. Tailored angiography is essential for evaluating in situ grafts, and interventional techniques are extremely useful for managing complications.