如何避免激光术后常见并发症

据一位经验丰富的激光外科医师说,通常所认为激光能够毫无损伤去除毛发、文身和胎记的观念是错误和有害的. C.B. Zachary医师是旧金山加利福尼亚大学皮肤外科和激光中心的临床教授和主任,他认为在医疗机构中,激光只能由经验丰富的护士和技师在皮肤科医师或其他经过相应训练的内科医师监督下实施.     

Mechanisms of pulmonary dysfunction after on-pump and off-pump cardiac surgery: a prospective cohort study

Background  

Pulmonary dysfunction following cardiac surgery is believed to be caused, at least in part, by a lung vascular injury and/or atelectasis following cardiopulmonary bypass (CPB) perfusion and collapse of non-ventilated lungs.     

Alcohol consumption as a risk factor for hepatocellular carcinoma in urban southern African blacks.

Our purpose was to ascertain whether alcohol abuse is a risk factor for the development of hepatocellular carcinoma in urban southern Africa blacks and, if so, to relate alcohol consumption to other possible risk factors such as persistent hepatitis-B-virus infection, smoking, male sex, in this subpopulation. A prospective, hospital-based, case-control format involving 101 patients with hepatocellular carcinoma and 101 controls was used. The mean age of the patients was 53.7 +/- 1.85 years and the male:female ratio 3.2:1. An increased risk was found, but only in urban men over the age of 40 years who habitually drank more than 80 g of ethanol daily. The risk remained after adjusting for chronic hepatitis-B infection, smoking, and sex (odds ratio 4.4, 95% confidence interval 1.3 to 16.6; p = 0.003). Smoking proved not to be a risk factor, either alone or in concert with alcohol consumption. Hepatitis-B infection was confirmed as a major risk in younger men and in women, but in urban men over the age of 40 years alcohol abuse was a greater risk. Current hepatitis-B infection and alcohol abuse were additive risks.     

Phenotype of endomyocardial biopsy-derived T-lymphocyte cultures and chronic rejection after heart transplantation

Chronic rejection (CR) is a major problem in long-term survival in heart transplantation. We analysed whether the occurrence of CR correlates with the incidence of acute rejections (AR) or with characteristics of endomyocardial biopsy-derived cell cultures. CR was diagnosed by annual angiography and defined as all coronary vascular changes. One year after transplantation 24 of the 63 patients had CR (38%). The incidence of AR in CR + and CR — patients was comparable. The patients in both groups had similar individual median percentages of EMB-yielding cell cultures. During the first year the CR — patients had more cultures in which at least 60% of the cells were CD4 + T cells (50% vs 37%, P = 0.05), due to a stronger CD4 predominance in the first 6 months. In the second year the CD4 predominance in the patients diagnosed as CR + after 1 year tended to be higher (P = 0.08). The patients had comparable percentages of cultures predominated by CD8 + T cells, γδ T cells or NK cells, irrespective of the time interval. These results might indicate that CD4 + T lymphocytes play a dual role in the aetiology of CR.     

Antibiotic-Induced Release of Lipoteichoic Acid and Peptidoglycan from Staphylococcus aureus: Quantitative Measurements and Biological Reactivities

Antibiotics with different mechanisms of action may vary with respect to their effects on the release and immunostimulatory activities of cell wall fragments from gram-positive bacteria. Therefore, after Staphylococcus aureus was cultured for 4 h in the absence of antibiotics (control) and in the presence of β-lactam antibiotics (imipenem, flucloxacillin, or cefamandole) and protein synthesis-inhibiting antibiotics (erythromycin, clindamycin, or gentamicin), the lipoteichoic acid (LTA) and peptidoglycan (PG) levels in the bacterial supernatants were measured. β-Lactam antibiotics greatly enhanced the release of LTA and PG (4- to 9-fold and 60- to 85-fold, respectively), whereas protein synthesis inhibitors did not affect PG release and even inhibited the release of LTA compared to the amount of LTA released in control cultures. The capacity of β-lactam supernatants to stimulate the production of tumor necrosis factor alpha and interleukin-10 in human whole blood was significantly higher than that of protein synthesis inhibitor or control supernatants; the amounts of these cytokines released were directly proportional to the concentrations of PG and LTA in the supernatants. Enzymatic degradation of PG in the supernatants indicated that PG was mainly responsible for the observed biological reactivity.     

Infectious salmon anemia virus (ISAV) genomic segment 3 encodes the viral nucleoprotein (NP), an RNA-binding protein with two monopartite nuclear localization signals (NLS)

Infectious salmon anemia virus (ISAV) is the type species of the genus Isavirus belonging to the Orthomyxoviridae, and causes serious disease in Atlantic salmon (Salmo salar). This study presents the expression and functional analysis of the ISAV genome segment 3, and provides further evidence that it encodes the viral nucleoprotein (NP). The encoded protein was expressed in a baculovirus system, and Western blot analysis showed that it corresponds to the 66-71 kDa structural protein previously found in purified ISAV preparations. RNA-binding activity was established by the interaction of viral and recombinant NP with single-stranded RNA transcribed in vitro. Immunofluorescence studies of infected cells showed the ISAV NP to be an early protein. It locates to the nucleus of infected cells before it is transported to the cytoplasm prior to virus assembly. A similar localization pattern was observed in cells transfected with the NP gene, confirming that the encoded protein has an intrinsic ability to be imported into the nucleus. Two monopartite nuclear localization signals (NLS) at amino acids (230)RPKR(233) and (473)KPKK(476) were identified by computer analysis, and validated by site-directed mutagenesis. In contrast to other orthomyxovirus-NPs, that have several NLSs that function independent of each other, both NLSs had to be present for the ISAV NP protein to be transported into the nucleus, indicating that these motifs cooperate to target the protein to the nucleus.     

The differential effects of bacterial lipopolysaccharide (LPS) on splenic non-lymphoid cells demonstrated by monoclonal antibodies.

In the present study, the effect of LPS on different splenic non-lymphoid cells was investigated. Marginal zone (MZ) macrophages, marginal metallophils and interdigitating cells (IDC) were demonstrated using specific monoclonal antibodies in a two-step immunoperoxidase procedure in combination with enzyme histochemistry. The results indicate that the number of marginal zone macrophages decreases markedly after LPS treatment, but is followed by a rapid repopulation as observed by monoclonal antibody staining and selective uptake of FITC-Ficoll. Marginal metallophils are normally located at the inner border of the marginal sinus and can specifically be identified by the monoclonal antibody MOMA-1. Following LPS stimulation, many MOMA-1-positive cells were present in the corona and central parts of the follicles, with decreasing numbers near the marginal sinus. These findings strongly suggest that LPS induces a migration of marginal metallophils towards the follicle centres. Most of the tangible body macrophages in the follicle centres appeared to be slightly MOMA-1-positive, which indicates that marginal metallophils may, at least under certain circumstances, differentiate into tangible body macrophages. In the inner PALS, many interdigitating cells, NLDC-145-positive cells, can be found. The number of NLDC-145-positive cells was shown to be severely decreased at later time-intervals after LPS administration, resulting in an almost unstained inner PALS at 2 days. In contrast to the above-mentioned splenic non-lymphoid cells, the red pulp macrophages are only minimally affected by LPS.     

House dust mite allergen avoidance and self-management in allergic patients with asthma: randomised controlled trial

BACKGROUND: The efficacy of bed covers that are impermeable to house dust mites has been disputed. AIM: The aim of the present study was to investigate whether the combination of 'house dust mite impermeable' covers and a self-management plan, based on peak flow values and symptoms, leads to reduced use of inhaled corticosteroids (ICS) than self-management alone. DESIGN OF STUDY: Prospective, randomised, double blind, placebo-controlled trial. SETTING: Primary care in a south-eastern region of the Netherlands. METHOD: Asthma patients aged between 16 and 60 years with a house dust mite allergy requiring ICS were randomised to intervention and placebo groups. They were trained to use a self-management plan based on peak flow and symptoms. After a 3-month training period, the intervention commenced using house dust mite impermeable and placebo bed covers. The follow-up period was 2 years. Primary outcome was the use of ICS; secondary outcomes were peak expiratory flow parameters, asthma control, and symptoms. RESULTS: One hundred and twenty-six patients started the intervention with house dust mite impermeable or placebo bed covers. After 1 and 2 years, significant differences in allergen exposure were found between the intervention and control groups (P<0.001). No significant difference between the intervention and control groups was found in the dose of ICS (P = 0.08), morning peak flow (P = 0.52), peak flow variability (P = 0.36), dyspnoea (P = 0.46), wheezing (P = 0.77), or coughing (P = 0.41). There was no difference in asthma control between the intervention and control groups. CONCLUSION: House dust mite impermeable bed covers combined with self-management do not lead to reduced use of ICS compared with self-management alone.     

Clinical effectiveness of a mite allergen-impermeable bed-covering system in asthmatic mite-sensitive patients

BACKGROUND: Exposure to allergens plays a role in the development of bronchial hyperresponsiveness and in the chronic inflammatory response seen in asthmatic patients. House dust mites (HDMs) are an important source of allergen. Reduction of these allergens might lead to better lung function and reduction of asthma symptoms. OBJECTIVE: The effect of HDM-impermeable covers on HDM allergen levels, peak flow values, and asthma symptoms were measured. Therefore a randomized clinical trial was carried out. METHODS: Fifty-two allergic asthmatic patients were randomly allocated to use the HDM-impermeable or placebo covers. During the study period, daily peak flow and asthma symptom scores were recorded. Dust samples were taken from the mattresses. RESULTS: We observed a significant reduction in HDM allergen levels on the mattresses after encasing them with HDM-impermeable covers (reduction of 87% of Der p 1 in micrograms per gram of dust; P <.001). Baseline symptoms were so low that no improvement could be established. Morning peak expiratory flow is significantly higher in the intervention group compared with that seen in the placebo group during the study period (beta=20.2; P <.01). CONCLUSIONS: HDM-impermeable covers significantly decreased the level of HDM allergens. Furthermore, morning peak flow was significantly increased during the intervention period. This study indicates that HDM allergen-avoidance measures might have beneficial effects on allergen reduction and asthma outcome.