Interventional radiologic procedures in the renal transplant

Percutaneous interventional procedures can be valuable in the evaluation and treatment of urologic complications of renal transplantation. Thirty-three patients underwent percutaneous procedures, including relief of obstruction by catheter nephrostomy, diagnostic antegrade pyelography with Whitaker testing, aspiration of various fluid collections (lymphocele, hematoma, urinoma, and abscess), and renal artery angioplasty, during a three year period at three institutions, to provide temporizing treatment and anatomic data. Surgical intervention was sometimes avoided, but more often it could be deferred to allow the patient to stabilize prior to surgery. Complications that required surgery occurred in two patients.     

Rosette inhibitory factor: T-lymphocyte subpopulation specificity and potential immunoregulatory role in hepatitis B virus infection

We have observed the disappearance of rosette inhibitory factor (RIF) from the serum of 19 patients with acute hepatitis B virus infection. This occurred at a time coinciding with the detection of anti-HBs. In addition, levels of RIF activity were significantly greater (P less than 0.001) in 35 HBsAg carriers who lacked anti-HBs when compared to 15 carriers who regularly demonstrated this antibody. In all instances, RIF effect was partial affecting some, but not all, T-lymphocytes from healthy donors were separated into TM (helper), TG (suppressor), and T0 (null) subpopulations by an immunoglobulin-ox-cell rosette depletion method. The effect of RIF on erythrocyte rosette formation and Fc-receptor expression in these subpopulations was assessed. TG-lymphocytes were found to be refractory to RIF-mediated suppression of erythrocyte rosette formation while TM-lymphocytes demonstrated an enhanced sensitivity to RIF. Incubation of TG-lymphocytes, potential TM-percursor cells, with RIF resulted in a decreased expression of new IgM-Fc receptors. In order to determine if any functional significance could be derived from these findings, the effect of RIF on in vitro immunoglobulin secretion was tested. Using pokeweed mitogen-stimulated mononuclear cell cultures, purified RIF-low density lipoprotein was shown to suppress IgM, IgG, and IgA secretion by 75.3, 74.3, and 59.3%, respectively. These data are consistent with the hypothesis that RIF is a potential immunoregulatory protein which could contribute to the lack of anti-HBs noted during the acute phase of hepatitis B and in the majority of HBsAg carriers.     

The scaphoid compression staple: an effective form of fixation

This paper involves an overview of bone healing with its relationship to tension and compression of osteotomy sites, followed by a presentation on the use of the Richards scaphoid compression staple as an effective form of fixation for closing abductory base wedge osteotomies.     

Vasoactive intestinal peptide and pituitary adenylate cyclase- activating polypeptides (PACAP27) and PACAP38) protect CD4+CD8+ thymocytes from glucocorticoid-induced apoptosis

In the present study, the effects of vasoactive intestinal peptide (VIP) and the pituitary adenylate cyclase-activating polypeptides, PACAP27 and PACAP38, in a concentration range from 10(-13) to 10(-6) mol/L were studied in vitro on the spontaneous and dexamethasone (DEX)- induced apoptosis in rat thymocytes. The results show that VIP and both PACAPs inhibit significantly and in a similar way the DNA fragmentation characteristic of glucocorticoid-induced apoptosis and increase the cell survival of thymocytes, with a maximal effect observed at 10(-8) to 10(-9) mol/L. This study showed the ability of the VIP-receptor (VIP- R) antagonist [N-Ac-Tyr1,D-Phe2]-GRF(1-29) amide to partially reverse the inhibitory effect of VIP and both PACAPs on DEX-induced apoptosis, providing evidence for a specific VIP1-R-mediated response and supporting the involvement of a single receptor for the three neuropeptides. Phenotypic analysis showed that VIP, PACAP27, and PACAP38 protect predominantly CD4+CD8+ thymocytes from glucocorticoid- induced apoptosis. These findings suggest that these neuropeptides could be involved in intrathymic T-cell maturation.     

Human immunodeficiency virus seroprevalence among blood product recipients in San Francisco before transfusion

To determine the incidence of transfusion-associated human immunodeficiency virus (HIV) infection after routine screening of donated blood, a pilot study estimated the pretransfusion prevalence of HIV infection among blood product recipients in San Francisco. Among the 911 nonduplicate pretransfusion specimens from recipients without a clinical history of acquired immune deficiency syndrome (AIDS) or AIDS-related complex (ARC), the overall prevalence of antibody to HIV was 2.9 percent (5.2% among males and 0.6% among females; p = 0.00002). If recipients in specifically defined or possible high-risk groups (n = 348) were excluded, a seropositivity rate of 1.8 percent (10/563) was detected, with all the positives occurring in men (10/242, 4.1%) and none in women (0/321, 0%). This demonstrated prevalence of HIV infection among blood product recipients in San Francisco before transfusion was substantially higher than the known 0.02 to 0.04 percent prevalence in the donor population. Therefore, the population of women without known risk for AIDS is the best in which to assess the risk of HIV infection in patients who are currently receiving seronegative blood transfusions.     

Denaturing interaction between sickle hemoglobin and phosphatidylserine liposomes

It is hypothesized that abnormal interaction between sickle hemoglobin (HbS) and erythrocyte membrane lipid might promote deposition of denatured hemoglobin (hemichrome) on the membrane. We compared the interaction of HbS and normal HbA with large unilamellar phosphatidylserine (PS) liposomes under low salt/pH conditions. Admixture of oxyHb and dioleoyl-PS resulted in loss of absorbance at 412 nm, the apparent first order rate constant for which was .25 +/- 0.02 hour-1 for HbA and .85 +/- 0.18 hour-1 for HbS. This was ascribable largely to formation of metHb and hemichromes and was accompanied by some actual transfer of heme from hemoglobin to lipid phase. By comparison, admixture of oxyHb with liposomes made from bovine brain PS having unsaturated acyl chains promoted even faster absorbance loss if the starting liposomal material contained detectable peroxidation by-product. In such cases, actual heme destruction developed with accompanying liberation of free iron and promotion of lipidperoxidation. Fluorescence quenching experiments indicate that hemoglobin/lipid interaction is characterized by very rapid initial electrostatic interaction, followed by development of irreversible changes. Similar changes still occur under conditions of physiologic salt/pH, but they develop much more slowly. The 3.4-fold faster oxidation of HbS versus HbA on lipid observed here represents an additional augmentation of the disparity in oxidation rates for hemoglobins in solution (1.7-fold faster for HbS than for HbA) observed previously. The accelerated promotion of Hb denaturation resulting from lipid contact may help explain deposits of hemichrome on sickle red blood cell membranes, particularly because these cells are in double jeopardy by virtue of having both the mutant HbS and abnormal amounts of peroxidized membrane lipid.     

Long-term bone marrow culture in persons with Fanconi anemia and bone marrow failure

Fanconi anemia is an autosomal recessive disease characterized by a high risk of developing bone marrow (BM) failure and acute myelogenous leukemia. We studied growth of hematopoietic progenitor cells in long- term BM culture (LTBMC) in 8 persons with Fanconi anemia and BM failure. Although LTBMC were initiated with very few BM cells, an adherent layer formed in cultures from 7 persons. In these cultures, the number of nonadherent cells increased for 10 to 15 days. Cell growth continued until cultures were terminated at day 35 to 40. During the first 2 weeks of culture, most nonadherent cells were differentiated myeloid cells. By days 35 to 40, the adherent layer contained cells able to initiate secondary LTBMCs. These data indicate that hematopoietic precursors cells able to proliferate and differentiate in vitro are present in the BM of persons with Fanconi anemia and BM failure. They suggest that mechanisms other than absent precursor cells are responsible for BM failure in Fanconi anemia.     

A partial characterization of hepatitis B e antigen.

Partially purified hepatitis B e antigen (HBeAG) was prepared by ultracentrifugation, ammonium sulfate precipitation, and molecular sieve chromatography of sera obtained from asymptomatic carriers of hepatitis B surface antigen. The antigenic specificity of the HBeAG preparations was investigated further with affinity chromatography. The results indicated that HBeAG is distinct and separable from DNA polymerase activity. Columns coupled with either goat IgG prepared from antiserum to human IgG or antibody to HBeAg bound all detectable HBeAg and bound 31% and 100% of the IgG, respectively, from a partially purified HBeAg preparation. Rate zonal sucrose sedimentation and molecular sieve and ion-exchange chromatography indicated a variability in molecular weight and charge; this finding suggested a heterogenous population of immunoreactivities containing HBeAg. Our preliminary results suggest the existence of an HBeAg-IgG complex.