Ovarian sympathectomy in the guinea pig

The influence of ovarian adrenergic nerves on follicular growth during the estrous cycle in the adult guinea pig was ascertained by comparing follicular development in control and chemically sympathectomized ovaries from the same animal. Selective ovarian sympathectomy was achieved by injecting 6-hydroxydopamine into a surgically closed periovarian membranous sac (bursa) on day 2 of the cycle (day 1 = day of estrus). The contralateral surgically closed ovarian bursa was injected with solvent used for 6-hydroxydopamine. Animals were laparotomized on days 5, 10 and 14 of the cycle. Blood from the utero-ovarian vein was collected bilaterally for measurement of progesterone and androstenedione. The ovaries were processed for histologic examination, and the number of follicles in each ovary was analyzed morphometrically. Sympathectomy on day 2 caused a decrease in healthy preovulatory follicles (greater than 700 micron diameter) on day 10 of the cycle. There were no differences in ovarian weights or the total number of follicles per ovary at this time. On days 5 and 14 of the cycle, there were no differences in ovarian weights, total number of follicles per ovary or follicles in any size classification. Sympathectomy did not alter progesterone levels in the utero- ovarian vein as compared to contralateral control levels. From control ovaries, there was a significant increase in progesterone in the blood of the utero-ovarian vein on day 10 but venous levels of progesterone from sympathectomized ovaries were not significantly different at any day of the cycle. In the venous effluent from sympathectomized ovaries, androstenedione was elevated at day 5 compared to days 10 and 14.(ABSTRACT TRUNCATED AT 250 WORDS)     

Blood transfusion and renal allograft survival.

Thirty-two first renal transplantations with cadaveric allografts were reviewed to see how many of the recipients had received blood transfusions preoperatively. There was a significant difference in transplant survival between patients who had and patients who had not received blood transfusion before transplantation; this difference was entirely due to acute rejection within three months after transplantation in patients who had not received transfusion. Other factors studied had no effect on survival.     

Differential responsiveness to immunoablative therapy in refractory rheumatoid arthritis is associated with level and avidity of anti-cyclic citrullinated protein autoantibodies: a case study

In order to identify pathogenic correlates of refractory rheumatoid arthritis (RA), antibodies against anti-cyclic citrullinated protein (ACPAs) were investigated in RA patients in whom the dysregulated immune system had been ablated by high-dose chemotherapy (HDC) and autologous haematopoietic stem cell transplantation (HSCT). Six patients with refractory RA were extensively characterized in terms of levels of total immunoglobulins, RA-specific autoantibodies (ACPAs and rheumatoid factor) and antibodies against rubella, tetanus toxoid (TT) and phosphorylcholine before and after HDC plus HSCT. Additionally, the avidity of ACPAs was measured before and after treatment and compared with the avidity of TT antibodies following repeated immunizations. Synovial biopsies were obtained by arthroscopy before HDC plus HSCT, and analyzed by immunohistochemistry. In the three patients with clinically long-lasting responses to HDC plus HSCT (median 423 days), significant reductions in ACPA-IgG levels after therapy were observed (median level dropped from 215 to 34 arbitrary units/ml; P = 0.05). In contrast, stable ACPA-IgG levels were observed in three patients who relapsed shortly after HDC plus HSCT (median of 67 days). Clinical responders had ACPA-IgG of lower avidity (r = 0.75; P = 0.08) and higher degree of inflammation histologically (r = 0.73; P = 0.09). Relapse (after 38 to 530 days) in all patients was preceded by rising levels of low avidity ACPA-IgG (after 30 to 388 days), in contrast to the stable titres of high avidity TT antibodies. In conclusion, humoral autoimmune responses were differentially modulated by immunoablative therapy in patients with synovial inflammation and low avidity ACPA-IgG autoantibodies as compared with patients with high levels of high avidity ACPA-IgG. The distinct clinical disease course after immunoablative therapy based on levels and avidity of ACPA-IgG indicates that refractory RA is not a single disease entity.     

Lipid specific activation of the murine P4-ATPase Atp8a1 (ATPase II)

The asymmetric transbilayer distribution of phosphatidylserine (PS) in the mammalian plasma membrane and secretory vesicles is maintained, in part, by an ATP-dependent transporter. This aminophospholipid "flippase" selectively transports PS to the cytosolic leaflet of the bilayer and is sensitive to vanadate, Ca(2+), and modification by sulfhydryl reagents. Although the flippase has not been positively identified, a subfamily of P-type ATPases has been proposed to function as transporters of amphipaths, including PS and other phospholipids. A candidate PS flippase ATP8A1 (ATPase II), originally isolated from bovine secretory vesicles, is a member of this subfamily based on sequence homology to the founding member of the subfamily, the yeast protein Drs2, which has been linked to ribosomal assembly, the formation of Golgi-coated vesicles, and the maintenance of PS asymmetry. To determine if ATP8A1 has biochemical characteristics consistent with a PS flippase, a murine homologue of this enzyme was expressed in insect cells and purified. The purified Atp8a1 is inactive in detergent micelles or in micelles containing phosphatidylcholine, phosphatidic acid, or phosphatidylinositol, is minimally activated by phosphatidylglycerol or phosphatidylethanolamine (PE), and is maximally activated by PS. The selectivity for PS is dependent upon multiple elements of the lipid structure. Similar to the plasma membrane PS transporter, Atp8a1 is activated only by the naturally occurring sn-1,2-glycerol isomer of PS and not the sn-2,3-glycerol stereoisomer. Both flippase and Atp8a1 activities are insensitive to the stereochemistry of the serine headgroup. Most modifications of the PS headgroup structure decrease recognition by the plasma membrane PS flippase. Activation of Atp8a1 is also reduced by these modifications; phosphatidylserine-O-methyl ester, lysophosphatidylserine, glycerophosphoserine, and phosphoserine, which are not transported by the plasma membrane flippase, do not activate Atp8a1. Weakly translocated lipids (PE, phosphatidylhydroxypropionate, and phosphatidylhomoserine) are also weak Atp8a1 activators. However, N-methyl-phosphatidylserine, which is transported by the plasma membrane flippase at a rate equivalent to PS, is incapable of activating Atp8a1 activity. These results indicate that the ATPase activity of the secretory granule Atp8a1 is activated by phospholipids binding to a specific site whose properties (PS selectivity, dependence upon glycerol but not serine, stereochemistry, and vanadate sensitivity) are similar to, but distinct from, the properties of the substrate binding site of the plasma membrane flippase.     

Transitional cell carcinoma of the ovary: A rare case and review of literature

Goblet cell carcinoid of the large intestine is a rare neoplasm, usually located in ascending colon and rectum. A 60-year-old male patient underwent surgery after the diagnosis of acute abdomen. Exploratory laparotomy revealed perforation with a diameter of 1 cm at the site of the previously performed gastroenterostomy and dilatation of the right colic flexure, secondary to a solid obstructive mass located in the mid-portion of transverse colon. Histopathological investigation of the biopsies, taken from the gastroenterostomy site and the tumor, revealed mixed carcinoid-adenocarcinoma with carcinoid component, predominantly composed of goblet cells. Three cycles of FOLFOX-4 protocol was administered. Following respiratory distress secondary to pulmonary metastasis, the patient's condition deteriorated and subsequently died in the fourth postoperative month. Our aim with this paper is to point out that more cases should be reported for more effective diagnosis, histopathological study, clinical investigation, treatment and prognosis of this specific neoplasm.     

Prospective cohort studies on risk factors for cardiovascular events in systemic lupus erythematosus: a major challenge

Cardiovascular disease (CVD) has been identified as a major contributor to morbidity and mortality in patients with systemic lupus erythematosus (SLE). The etiology of premature CVD in SLE is supposed to have many factors, including traditional coronary artery disease (CAD) risk factors, antiphospholipid antibodies, and metabolic and inflammatory factors. Despite the overwhelming interest in CVD in SLE research, prospective studies evaluating risk factors for hard endpoints (that is, cardiovascular events) are relatively scarce. The article by Gustafsson and colleagues suggests that prothrombotic factors play an important role in SLE-related CVD and that the influence of traditional CAD risk factors might be limited.     

Effects of space flight on the immunohistochemical demonstration of connexin 26 and connexin 43 in the postpartum uterus of rats

The effect of space flight in a National Aeronautics and Space Administration shuttle was studied in pregnant rats. Rats were launched on day 11 of gestation and recovered on day 20 of gestation. Pregnancy was allowed to proceed to term and rats delivered vaginally on days 22-23, although flight animals required more labour contractions to complete the delivery process. Pups were placed with foster dams and connexin 26 and 43 were examined in the uterus of flight animals approximately 3 h after delivery. Space flight did not affect uterine connexin 26, localized primarily in epithelial cells of the endometrium, but decreased connexin 43, the major gap junction protein in the myometrium. It is suggested that decreased connexin 43 alters synchronization and coordination of labour contractions, resulting in a requirement for more contractions to complete the delivery process.     

Human ferrochelatase: crystallization, characterization of the [2Fe-2S] cluster and determination that the enzyme is a homodimer

Ferrochelatase (protoheme ferrolyase, EC 4.99.1.1) catalyzes the terminal step in the heme biosynthetic pathway, the insertion of ferrous iron into protoporphyrin IX to form protoheme IX. Previously we have demonstrated that the mammalian enzyme is associated with the inner surface of the inner mitochondrial membrane and contains a nitric oxide sensitive [2Fe-2S] cluster that is coordinated by four Cys residues whose spacing in the primary sequence is unique to animal ferrochelatase. We report here the characterization and crystallization of recombinant human ferrochelatase with an intact [2Fe-2S] cluster. Gel filtration chromatography and dynamic light scattering measurements revealed that the purified recombinant human ferrochelatase in detergent solution is a homodimer. EPR redox titrations of the enzyme yield a midpoint potential of -453+/-10 mV for the [2Fe-2S] cluster. The form of the protein that was crystallized has a single Arg to Leu substitution. This mutation has no detectable effect on enzyme activity but is critical for crystallization. The crystals belong to the space group P2(1)2(1)2(1) and have unit cell constants of a=93.5 A, b=87.7 A, and c=110.2 A. There are two molecules in the asymmetric unit and the crystals diffract to better than 2.0 A resolution. The Fe to Fe distance of the [2Fe-2S] cluster is calculated to be 2.7 A based upon the Bijvoet difference Patterson map.