Negative charge distribution and density on the surface of oxygenated normal and sickle red cells

Negative charges on the external surface of red cells were visualized by colloidal iron hydroxide labelling of 50% of the membrane area after osmotic hemolysis and glutaraldehyde fixation. Counts were made over randomly selected areas on electron micrographs at 350,000 x magnification. Statistical analyses showed that at the 95% level of confidence there was no significant difference between oxygenated normal (AA) and sickle (SS) cells in either the distribution or the density of negative charges.     

运动性心律失常

运动性心律失常是指发生于机体剧烈运动期间或之后的心律失常。临床表现不一,从心悸、头晕、晕厥、心绞痛、急性心肌梗死和充血性心力衰竭,甚至到心脏性猝死。运动性心律失常可见于心肌缺血,如患有动脉粥样硬化性心脏病以及患有原发性或继发性心肌病的患者。然而,也可能发生在似乎健康的个体。在后一组人群中,运动性心律失常可以是良性的,但也可以是获得性(如药物诱发)或先天性(如先天性长QT综合征或致心律失常性右室发育不良)心电活动或结构的异常而呈恶性。这种潜在病理生理学机制的复杂性,使运动性心律失常的诊断和治疗成为临床医学上的…     

Cyclic changes in the concentration of glucose and fructose in human cervical mucus.

OBJECTIVE: To determine a possible cyclic change in the concentration of glucose and fructose in the aqueous phase of human cervical mucus (CM). DESIGN: Concentrations of glucose and fructose were longitudinally determined in the aqueous phase of CM of normal cycling women using enzymatic techniques, modified for small quantities. SETTING: Patients visiting a fertility clinic were selected. PATIENTS: Nine healthy women with regular menstrual cycles of 28 +/- 3 days that appeared to be ovulatory, demonstrated by sonographic follicle immaging and serum progesterone (P) measurements. INTERVENTIONS: Cervical mucus samples were longitudinally collected preovulatory, postovulatory, and premenstrual in ovulatory cycles, monitored by ultrasound and blood estradiol and P measurements. MAIN OUTCOME MEASURES: The study was designed to measure glucose and fructose longitudinally on three different points during one cycle. RESULTS: The preovulatory glucose concentrations in CM were lower than postovulatory and premenstrual. The preovulatory fructose concentrations were lower than premenstrual. The glucose concentration correlated with the blood P level. CONCLUSION: There is a consistent change in the glucose concentration measured in human CM in three phases of the menstrual cycle. The preovulatory and premenstrual fructose concentrations differ significantly. Knowledge of the carbohydrate metabolism in human cervical mucus may contribute in illuminating the possible role of the carbohydrate metabolism in sperm migration at midcycle and implantation in the luteal phase.     

Vertical transmission of Kaposi's sarcoma

AIDS related Kaposi's sarcoma is commonly seen in homosexual men, only occasionally in men and women with heterosexually acquired HIV, and extremely rarely in children. The case of an HIV infected mother and her vertically infected child who both developed visceral Kaposi's sarcoma is reported. It is proposed that the putative Kaposi's sarcoma agent may also be transmitted vertically.     

The immunohistology of follicle lysis in lymph node biopsies from homosexual men

Follicle lysis is a characteristic alteration of B cell follicles described recently in lymph node biopsies from homosexual men. It consists of disruption of germinal centers by aggregates of small mature lymphocytes variably associated with erythrocyte extravasation. We studied the immunohistology of follicle lysis identified in lymph node biopsies from 11 homosexual men. The results indicate that follicle lysis has two principal immunohistologic features: (1) intrafollicular aggregates of small lymphocytes predominantly of polytypic mantle B cell phenotype (T015+/Leu-8+/mu+/delta+/k+ or lambda+), and (2) disruption of the normal, unified follicular meshwork of R4/23+ dendritic reticulum cells by these B cell aggregates. These structural alterations may affect the functional integrity of the germinal center as it pertains to the abnormal B cell effector function and the increased prevalence of B cell lymphoma recently documented in the acquired immunodeficiency syndrome and related disorders. Because dendritic reticulum cells weakly express the Leu-3 (T4) antigen, which is known to be an essential component of the receptor for human T- lymphotropic virus type III/lymphadenopathy-associated virus (HTLV- III/LAV) retrovirus infection, it is possible that retroviral infection of dendritic reticulum cells may play a role in the pathogenesis of follicle lysis.     

Dural infolding during C1-2 myelography

Inward buckling of the dura at C1-2 may occasionally occur with hyperextension of the neck and can result in a difficult or unsuccessful puncture when the posterior lateral C1-2 approach is used for cervical myelography. In this circumstance, placement of the head in a neutral or slightly flexed position may widen the posterior subarachnoid space and facilitate the needle puncture.     

Remodeling of gap junctions in mouse hearts hypertrophied by forced retinoic acid signaling

BACKGROUND: Beta-MHC-hRARalpha transgenic mice express a constitutively active (truncated) form of the human retinoic acid receptor which triggers development of dilated cardiomyopathy. In those hearts, we studied expression of gap junction proteins in relation to electrical impulse propagation. METHODS AND RESULTS: As compared to wildtype mice, hearts of 4-6 month old mice with 7-12 inserted hRARalpha copies are marked by an increased heart weight/body weight- and heart weight/tibia length ratio. 3-extremity lead ECGs revealed prolongation of the Q-j interval suggesting delayed ventricular activation. Mapping of electrical activity of epi- and endocardial left ventricular free wall revealed activation delay, increased heterogeneity in conduction and regional conduction block. Ventricular tachycardias did not occur spontaneously nor could be induced by ventricular pacing. Immunohistochemical analysis showed profound and heterogeneous redistribution and down-regulation of the gap junction protein connexin43 (Cx43) in the left ventricular free wall. Here, hRARalpha expression induced re-expression of the hypertrophic markers alpha-skeletal actin and beta-MHC, and in 3 out of 10 severely affected mice, re-expression of Cx40. Concomitant with changes in expression/distribution of Cx43, changes in expression and distribution of beta-catenin and N-cadherin (two other intercalated disk associated proteins) were observed. CONCLUSIONS: Beta-MHC-hRARalpha transgenic hearts show heterogeneous re-expression of (early) sarcomeric genes while expression of connexin43, N-cadherin and beta-catenin is down-regulated. We postulate that the resulting aberrant ventricular activation does not trigger development of lethal arrhythmias due to the small size of remaining healthy ventricular tissue where the transgene is not expressed.