Responses to questions by medical students about family practice

Medical students frequently have questions about the specialty of family practice. Responses to 30 questions commonly asked about family practice are presented with a review of recent literature. These responses may assist medical students and their advisors in considering the choice of family practice as a career.     

Role of the superior colliculus in the motor effects of cannabinoids and dopamine

We studied the cellular distribution of CB1 cannabinoid receptors in the superior colliculus of the rat using an antibody raised against the N-terminal of the receptor. The effect of unilateral cannabinoid receptor stimulation in the intermediate layers of the superior colliculus on rotational behavior in rats was also explored. The antibody against CB1 receptors outlined the crossed descending system of the superior colliculus (predorsal bundle output system) as well as the collicular commisure. The potent cannabinoid agonist CP55,940 (5 microgram/0.25 microliter) induced strong contralateral turning when microinjected unilaterally into the lateral intermediate layers of the superior colliculus. The levels of turning obtained with the intracollicular administration of the cannabinoid were comparable to the highest levels obtained with dopamine agonists in the basal ganglia. The D(2) dopamine agonist quinpirole or the D(1) dopamine agonist SKF82958 reversed this contralateral rotation but failed to affect motor behavior on their own. A new motor pathway for cannabinoids is discussed.     

Failures of Cu-Cu Joints under Temperature Cycling Tests

In this study, the failure mechanisms of Cu-Cu joints under thermal cycling were investigated. Two structures of dielectrics (PBO/underfill/PBO and SiO₂) were employed to seal the joints. Stress gradients induced in the joints with the different dielectrics were simulated using a finite element method (FEM) and correlated with experimental observations. We found that interfacial voids were forced to move in the direction from high stress regions to low stress ones. The locations of migrated voids varied with the dielectric structures. Under thermal cycling, such voids were likely to move forward to the regions with a small stress change. They relocated and merged with their neighboring voids to lower the interfacial energy.     

TβRⅡ,MMP-7,TIMP-2表达及在HNPCC侵袭转移中的作用

目的:通过观察TβRⅡ,MMP-7及TIMP-2在HNPCC和散发性大肠癌中的表达,探讨其在HNPCC侵袭转移的生物学行为中的作用.方法:选取1980-05/2005-06空军总医院收治的HNPCC和散发性大肠癌各30例,应用免疫组化SP染色法检测其肿瘤组织中TβRⅡ,MMP-7,TIMP-2的表达情况.结合其相应临床病理资料进行分析TβRⅡ,MMP-7,TIMP-2表达在HNPCC侵袭转移中的作用.结果:TβRⅡ,MMP-7,TIMP-2在HNPCC组的阳性表达率分别为4 0.0%,46.7%,63.3%;而在散发性大肠癌组的阳性表达率为73.3%,86.7%,20.0%.散发性大肠癌组中MMP-7( ～ )/TIMP-2(-)比例明显高于HNPCC组.而其MMP-7(-)/TIMP-2( ～ )者则明显少于HNPCC组.TβRⅡ,MMP-7,TIMP-2的阳性表达率与肿瘤的大小和部位无关.而与肿瘤的侵犯深度和转移与否密切相关.侵犯浆膜外组织和有转移者的MMP-7的阳性表达率明显增高,而TβRⅡ,TIMP-2的阳性表达率则明显降低(P＜0.05).在两组大肠癌中TβRⅡ与MMP-7呈正相关(r=0.735,P=0.000;r=0.792,P=0.000),TIMP-2与TβRⅡ(r=-0.582,P=0.001;r=-0.394,P=0.031)和MMP-7 (r=-0.473,P=0.008;r=-0.388,P=0.034)的表达均呈负相关.结论:TβRⅡ,MMP-7,TIMP-2在散发性大肠癌和HNPCC中的表达差异显著.TβRⅡ,MMP-7在散发性大肠癌中的表达率和表达强度明显高于HNPCC,而TIMP-2的表达结果则相反.因此,散发性大肠癌中MMP-7/TIMP-2的比例失衡明显高于HNPCC组.     

Injectable PLGA-Coated Ropivacaine Produces A Long-Lasting Analgesic Effect on Incisional Pain and Neuropathic Pain

The management of persistent postsurgical pain and neuropathic pain remains a challenge in the clinic. Local anesthetics have been widely used as simple and effective treatment for these 2 disorders, but the duration of their analgesic effect is short. We here reported a new poly lactic-co-glycolic acid (PLGA)-coated ropivacaine that was continuously released in vitro for at least 6 days. Perisciatic nerve injection of the PLGA-coated ropivacaine attenuated paw incision-induced mechanical allodynia and heat hyperalgesia during the incisional pain period, and spared nerve injury-induced mechanical and cold allodynia for at least 7 days postinjection. This effect was dose-dependent. Perisciatic nerve injection of the PLGA-coated ropivacaine did not produce detectable inflammation, tissue irritation, or damage in the sciatic nerve and surrounding muscles at the injected site, dorsal root ganglion, spinal cord, or brain cortex, although the scores for grasping reflex were mildly and transiently reduced in the higher dosage-treated groups.PerspectiveGiven that PLGA is an FDA-approved medical material, and that ropivacaine is used currently in clinical practice, the injectable PLGA-coated ropivacaine represents a new and highly promising avenue in the management of postsurgical pain and neuropathic pain.     

Antimicrobial Activity of Platelet‐Rich Plasma and Other Plasma Preparations Against Periodontal Pathogens

Background: In addition to releasing a pool of growth factors during activation, platelets have many features that indicate their role in the anti‐infective host defense. The antimicrobial activities of platelet‐rich plasma (PRP) and related plasma preparations against periodontal disease–associated bacteria were evaluated. Methods: Four distinct plasma fractions were extracted in the formulation used commonly in dentistry and were tested for their antibacterial properties against three periodontal bacteria: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. The minimum inhibitory concentration of each plasma preparation was determined, and in vitro time‐kill assays were used to detect their abilities to inhibit bacterial growth. Bacterial adhesion interference and the susceptibility of bacterial adherence by these plasma preparations were also conducted. Results: All plasma preparations can inhibit bacterial growth, with PRP showing the superior activity. Bacterial growth inhibition by PRP occurred in the first 24 hours after application in the time‐kill assay. PRP interfered with P. gingivalis and A. actinomycetemcomitans attachment and enhanced exfoliation of attached P. gingivalis but had no influences on F. nucleatum bacterial adherence. Conclusions: PRP expressed antibacterial properties, which may be attributed to platelets possessing additional antimicrobial molecules. The application of PRP on periodontal surgical sites is advisable because of its regenerative potential and its antibacterial effects.     

A 12-Year Ecological Study of Hip Fracture Rates among Older Taiwanese Adults

Hip fracture rates in Taiwan are among the highest in the world. The aim of this study was to describe the trends of hip fracture hospitalizations among Taiwanese elderly (aged ≥ 65 years) and the trends of antiosteoporosis medication expenditure from 1999 to 2010. We conducted an ecological study using inpatient health care-utilization data from the Department of Health, and medication expenditure data from the IMS Health, Taiwan. The International Classification of Disease, Clinical Modification, 9th version, code 820 was used to identify hip fracture hospitalizations. Medications included alendronate, calcitonin, ibandronate, raloxifene, strontium ranelate, teriparatide, and zoledronic acid. Year 2010 was assigned as the reference point for age-standardized rates, currency exchange (to the US dollar), and discount rates. Over the 12-year study period, age-standardized hip fracture hospitalizations decreased by 2.7 % annually (p for trend < 0.001) for Taiwanese elders. The decline was more obvious among those aged ≥75 years (6.1 %). However, the number of hip fracture hospitalizations increased from 14,342 to 18,023. Total hospitalization costs increased by US$0.6 ± 0.2 million annually (p for trend = 0.002); however, the per capita costs decreased by US$23.0 ± 8.0 (p for trend = 0.017). The total medication expenditure increased 7.2-fold, from US$8.1 million to US$58.9 million, accounting for an increase in the overall pharmaceutical market by fivefold, from 3.4 to 15.9 ‰ (both p for trend < 0.001). From 1999 to 2010, there was a decline in hip fracture rates among elderly Taiwanese adults with a concomitant increase in antiosteoporosis medication expenditure.     

A pilot randomized controlled trial to improve geriatric frailty

Background

Little is known of the importance of social support in the associations between psychological distress and somatic health problems and socio-economic factors among older adults living at home. The objectives of the present study were to investigate the associations of social support, somatic health problems and socio-economic factors with psychological distress. We also examined changes in the association of somatic health problems and socio-economic factors with psychological distress after adjusting for social support.

Methods

A random sample of 4,000 persons aged 65?years or more living at home in Oslo was drawn. Questionnaires were sent by post, and the total response was 2,387 (64%). Psychological distress was assessed using Hopkins Symptom Checklist (HSCL-10) and social support with the Oslo-3 Social Support Scale (OSS-3). A principal component analysis (PCA) included all items of social support and psychological distress. Partial correlations were used, while associations were studied by logistic regression.

Results

After adjusting for socio-demographics and somatic health problems, we reported a statistically significant association between psychological distress and social support: ??Number of close friends??, OR 0.61; 95% CI 0.47-0.80; ??Concern and interest??, OR 0.68; 95% CI 0.55-0.84. A strong association between lack of social support and psychological distress, irrespective of variables adjusted for, indicated a direct effect. The associations between psychological distress and physical impairments were somewhat reduced when adjusted for social support, particularly for hearing, whereas the associations between somatic diagnoses and psychological distress were more or less eliminated. Income was found to be an independent determinant for psychological distress.

Conclusions

Lack of social support and somatic health problems were associated with psychological distress in elders. Social support acted as a mediator, implying that the negative effect of somatic health problems, especially hearing, on psychological distress was mediated by low social support. We hypothesize that physical impairments reduced social support, thereby increasing psychological distress to a greater extent than the selected diagnoses. The combination of poor social support, poor somatic health and economic problems may represent a vulnerable situation with respect to the mental health of older persons. Free interventions that highlight social support should be considered in mental health promotion.