胸腺瘤合并重症肌无力危象30例围手术期的处理

0引言 胸腺切除是治疗重症肌无力(MG)的有效方法,有效率可达80%[1],但胸腺瘤术后常并发MG危象,导致死亡. 1992 02/2003 02我们共手术治疗89例胸腺瘤合并MG患者,术后发生MG 危象 30例,均抢救成功,无围手术期死亡.     

Independent initiation of primary electron transfer in the two branches of the photosystem I reaction center

Photosystem I (PSI) is a large pigment-protein complex that unites a reaction center (RC) at the core with ∼100 core antenna chlorophylls surrounding it. The RC is composed of two cofactor branches related by a pseudo-C2 symmetry axis. The ultimate electron donor, P₇₀₀ (a pair of chlorophylls), and the tertiary acceptor, F_X (a Fe₄S₄ cluster), are both located on this axis, while each of the two branches is made up of a pair of chlorophylls (ec2 and ec3) and a phylloquinone (PhQ). Based on the observed biphasic reduction of F_X, it has been suggested that both branches in PSI are competent for electron transfer (ET), but the nature and rate of the initial electron transfer steps have not been established. We report an ultrafast transient absorption study of Chlamydomonas reinhardtii mutants in which specific amino acids donating H-bonds to the 13¹-keto oxygen of either ec3_A (PsaA-Tyr696) or ec3_B (PsaB-Tyr676) are converted to Phe, thus breaking the H-bond to a specific ec3 cofactor. We find that the rate of primary charge separation (CS) is lowered in both mutants, providing direct evidence that the primary ET event can be initiated independently in each branch. Furthermore, the data provide further support for the previously published model in which the initial CS event occurs within an ec2/ec3 pair, generating a primary ec2⁺ec3^- radical pair, followed by rapid reduction by P₇₀₀ in the second ET step. A unique kinetic modeling approach allows estimation of the individual ET rates within the two cofactor branches.     

Verapamil as an adjunct to local anaesthetic for brachial plexus blocks

Background: Calcium channel blockers potentiate the effects of local anaesthetics. We examined the effect of adding verapamil to local anaesthetic solution on anaesthetic duration in patients undergoing surgery under brachial plexus block.     

Neurohydatidosis

Early and non‐invasive evaluation of hydatid infestation of brain and spine is of paramount importance, especially in endemic areas. We present a spectrum of imaging findings in neurohydatidosis with a brief review of literature.     

Primary mediastinal large cell lymphoma is characterized by an inverted pattern of large tumoral mass and low {beta}2 microglobulin levels in serum and frequently elevated levels of serum lactate dehydrogenase

BACKGROUND: Primary mediastinal large cell lymphoma (PMLCL) is an emergingentity. New parameters can help define it. MATERIALS AND METHODS: Retrospective analysis of medical records from 35 patients treatedat The University of Texas M.D. Anderson Cancer Center from1985 to 1990. Immunohistochemical evaluation of tissue specimens.Determination of survival (S) and time to treatment failure(TTF). RESULTS: The median age was 34 years and 69% were females. Eighty-threepercent presented with symptoms of mediastinal involvement.While 100% of the patients presented with bulky mediastinaldisease and 72% had elevated pretreatment serum lactate dehydrogenase,only 6% presented with an elevated pretreatment serum ß₂microglobulin. The lymphoma cells lacked CD21 staining. Forthe 18 patients treated initially at M.D. Anderson Cancer Center,S and TTF curves rates after doxorubicin-based regimens (plusradiotherapy in 14 cases) were 72% and 61%, respectively, at5 years follow-up (median, 42 months). Four out of six patientswho received autologous bone marrow transplant as salvage therapyare currently alive without disease at follow-up times of 21,25, 32, and 54 months. CONCLUSIONS: Primary mediastinal large cell lymphoma has characteristic clinicopathologicalfeatures to which another can be added, that of an invertedpattern of bulky disease, high LDH and low ß₂M inserum. The response to therapy is comparable to that of intermediate-gradelymphomas, although the numbers in the study are small. Ourpreliminary data suggest a possible role for autologous bonemarrow transplantation (ABMT) as salvage therapy. primary mediastinal lymphoma, clinical, pathology, prognosis     

Epstein-Barr virus-positive B-cell lymphoproliferative disorders arising in immunodeficient patients previously treated with fludarabine for low-grade B-cell neoplasms

We describe five patients with treated low-grade B-cell neoplasms who subsequently developed Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disorders (BLPDs). The low-grade B-cell neoplasms were B-cell chronic lymphocytic leukemia in four patients and splenic marginal zone lymphoma in one patient. All patients had received treatment with fludarabine for the low-grade B-cell neoplasm, and three had also received Campath-1H. The EBV-BLPDs arose 2-12 months after completion of fludarabine therapy and morphologically resembled the EBV-BLPDs that occur in the setting of iatrogenic immunodeficiency. Molecular genetic studies showed that these lesions were clonally distinct from the low-grade B-cell neoplasm in three of four cases assessed. Two patients did not receive therapy for the EBV-BLPD. The lesions regressed spontaneously in both patients but recurred in one. One patient underwent surgical excision and remains without evidence of the EBV-BLPD. One patient received aggressive multiagent chemotherapy with a complete response initially, but the EBV-BLPD recurred after 12 months. One patient received antiviral therapy and responded completely but died 2 months later of an opportunistic infection. We conclude that patients with low-grade B-cell neoplasms treated with fludarabine, possibly in combination with other immune suppressive agents, may subsequently develop EBV-BLPDs that morphologically resemble other iatrogenic immunodeficiency-associated BLPDs. Most are clonally distinct from the underlying low-grade B-cell neoplasm. A subset of these lesions may regress without systemic therapy.     

Hyperhomocysteinemia,and low intakes of folic acid and vitamin B12 in urban North India

Summary Background and Aim An adverse coronary risk profile has been reported amongst rural-to-urban migrant population living in urban slums undergoing stressful socio-economic transition. These individuals are likely to have low intakes of folic acid and vitamin B12, which may have an adverse impact on serum levels of homocysteine (Hcy). To test this hypothesis, we studied serum levels of Hcy in subjects living in an urban slum of North India and healthy subjects from urban non-slum area. Methods Group I consisted of 46 subjects (22 males and 24 females) living in an urban slum, while group II consisted of healthy subjects (n = 26, 13 males and 13 females) living in the adjacent non-slum area. Anthropometric measurements, biochemical profile (fasting blood glucose, total cholesterol, serum triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol) and fasting serum levels of Hcy were measured. Dietary intakes of folic acid, vitamin B12, vitamin B1, and iron were calculated by the 24-hour dietary recall method. Serum levels of Hcy were correlated with dietary intakes of nutrients, anthropometry, and metabolic variables. Results Sex-adjusted serum levels of Hcy in mmol/L (Mean ± SD) were high, though statistically comparable, in both the groups (group I: 20.8 ± 5.9 and group II: 23.2 ± 5.9). Overall, higher than normal serum levels of Hcy (> 15 μmol/L) were recorded in 84 % of the subjects. A substantial proportion of subjects in both groups had daily nutrient intakes below that recommended for the Asian Indian population (folic acid: 93.4 % in group I and 96.7 % in group II, vitamin B12: 76.1 % in group I and 88.4 % in group II). However, between the two groups, average daily dietary intakes of both the nutrients were statistically comparable. As compared to non-vegetarians, vegetarians showed lower intakes of folic acid (p < 0.01) and vitamin B12 (p < 0.01) in both groups. On multivariate linear regression analysis with serum Hcy as the response variable and vegetarian/non-vegetarian status and sex (male/female) as predictor variables, higher serum levels of Hcy were observed in vegetarians vs non-vegetarians (β = 4.6, p < 0.05) and males vs females (β = 5.3, p < 0.01). Conclusions Low intakes of folic acid and vitamin B12, and hyperhomocysteinemia, in both the healthy population living in urban slums and adjacent urban non-slum areas, are important observations for the prevention of nutritional and cardiovascular diseases in the Indian subcontinent. Received: 30 October 2001, Accepted: 14 January 2002