Decreased alloreactivity after vaccination against hepatitis B

The beneficial effect of blood transfusions on renal allografts disappeared at about the same time when hepatitis B vaccination was introduced in dialysis patients. To determine possible immunosuppressive effects of hepatitis B vaccination, we studied alloreactivity during the course of immunization. Fourteen healthy subjects without serological evidence of hepatitis B were routinely immunized against hepatitis B surface antigen. Plasma and mononuclear cells were isolated and frozen before immunization and after vaccination, respectively. Mean alloreactivity measured by [3H]thymidine uptake decreased from 64,772 cpm before immunization to 40,213 cpm after the third immunization. In crossover experiments, cellular modulation and plasma-dependent modulation of alloreactivity were observed. The immunosuppressive effect of plasma taken 4 weeks after the third vaccination correlated (r = 0.9) highly significantly (P < 0.005) with the anti-hepatitis B surface antigen antibody titer. Taken together, our data strongly suggest that hepatitis B vaccination is capable of reducing allogenic reactivity.

[Viruses and cell therapy. Evaluation of cell therapy from the virologic viewpoint]

The risks of cell therapy as seen by the microbiologist and virologist, are not calculable. Numerous viruses with longterm persistence in the host cells, cannot be detected on the basis of an acute disease in the host. This applies, for example to herpesviruses, lentiviruses, retroviruses, hepatitis C virus, Borna disease virus and the so-called unconventional viruses. There are two reasons why testing of the donor animal ist not possible, the first being the great number of potential pathogens, the second being the fact that for some of these agents there are no signs of a diagnostic approach involving isolation or antibody detection. e.g. scrapie (BSE). Further, so far unknown viruses must be expected.

Comparative analysis of intrathecal antibody synthesis and DNA amplification for the diagnosis of cytomegalovirus infection of the central nervous system in AIDS patients

We evaluated 49 paired cerebrospinal fluid (CSF) and serum samples of 35 patients infected with the human immunodeficiency virus type 1 (HIV-1) for laboratory evidence of cytomegalovirus (CMV) infection. The patients were grouped according to clinical criteria as probable CMV encephalitis/polyradiculomyelitis, CMV retinitis, cerebral toxoplasmosis, progressive multifocal leukoencephalopathy, HIV-1-related cognitive/motor complex, HIV-1-associated myelopathy, and other neurological diseases. Paired CSF and serum samples were analysed for CMV deoxyribonucleic acid (DNA) by polymerase chain reaction (PCR), quantitative intrathecal synthesis of immunoglobulin G (IgG) antibodies specific for recombinant phosphoprotein 150 (pp150) of CMV and CMV-specific serum IgM. Intrathecal synthesis of pp150-specific IgG was detected in 26% of patients (9/35), serum IgM was found in 23% of patients (8/35), and PCR of CSF was positive in 11% of patients (4/35). Detection of CMV-specific DNA in CSF preceded the intrathecal antibody synthesis in three patients for whom serial samples were available. PCR results of the CSF became negative in one patient with CMV polyradiculomyelitis after successful therapy with 9-[2-hydroxy-1-(hydroxymethyl) ethoxymethyl] guanine (DHPG). PCR has a higher diagnostic specificity in the acute phase of CMV infection than intrathecal antibody synthesis. The serum IgM response to CMV cannot be used to monitor a compartmentalized immune response in the central nervous system while an intrathecal immune response seems to be associated with recovery either spontaneously or as a result of treatment.

Nested PCR for specific detection and rapid identification of human picornaviruses

A nested PCR for the detection and rapid identification of human picornaviruses is described. Enteroviruses and rhinoviruses were amplified with the same set of four primers from the 5'-noncoding region. The nested primers allowed the detection of far less than 1 PFU in diluted virus stocks without Southern blot hybridization. In patients with neurological disorders (mainly aseptic meningitis), 43% of 37 specimens (11 of 21 cerebrospinal fluid specimens, 2 of 10 serum specimens, and 3 of 6 stool specimens) were positive by PCR. A total of 21% (10 of 47 specimens) of heart biopsy specimens from patients with dilative cardiomyopathy were PCR positive, whereas 3% (2 of 70 specimens) of control biopsy specimens from patients with coronary artery disease were PCR positive. PCR-amplified fragments from 27 of 29 clinical isolates and 14 of 28 patient samples were successfully serotyped by restriction enzyme digestion. Two specimens were further investigated by direct sequencing of PCR products, leading to the identification of a poliovirus type 3 isolate with a sequence that was highly divergent from previously published sequences.

[Acute cytomegalovirus gastritis after kidney transplantation. Its diagnosis by the polymerase chain reaction, antigenemia assay and immunohistochemistry]

To diagnose possible cytomegalovirus (CMV) infection in a 64-year-old man after renal transplantation, polymerase chain reaction (PCR), pp65 antigenaemia assay (pAA) and virus isolation in cell culture were routinely performed on a weekly basis. The PCR obtained virus DNA in peripheral blood lymphocytes for the first time in the fifth week. Two weeks later the patient complained of feeling unwell with abdominal pain and vomiting on eating. Two days later he developed a fever up to 38 degrees C and nocturnal sweats. Gastroscopy revealed marked antral gastritis which histologically showed typical cytomegalic "owl-eye" cells. The pAA was clearly positive and the cell culture started in the fifth week now showed a cytopathogenic effect. CMV gastritic having been diagnosed treatment consisted of 175 mg ganciclovir intravenously twice daily for 10 days. He became symptom-free after two days. The only side effects were thrombocytopenia down to 67,000/microliters and a rise in transaminase activities, changes which regressed later. To ensure early diagnosis and treatment of any CMV infection, specific virus diagnostic tests should be routinely undertaken after transplantation of organs from CMV-positive persons into CMV-negative patients.

Early diagnosis and successful treatment of acute cytomegalovirus encephalitis in a renal transplant recipient

We report the case of a 40-year-old male HIV-negative renal transplant patient with allograft rejection and immunosuppressive therapy who presented with acute cytomegalovirus (CMV) encephalitis. CT and MRI of the brain were normal but EEG showed diffuse slowing and dysrhythmia. In cerebrospinal fluid (CSF) initially 81 cells/microliters were found and immunocytochemistry showed a decreased CD4/CD8 ratio and increased values of activated lymphocytes, natural killer cells and immunoglobulin-containing cells. CMV-specific IgM antibodies in CSF and serum, immunostaining of CMV antigen in CSF cells and virus culture from CSF and urine were negative. During the first 3 weeks of illness no intrathecal production of immunoglobulins could be detected. Early diagnosis of CMV encephalitis was made by in situ hybridization (ISH) on CSF cell preparations and the polymerase chain reaction (PCR) which was positive in CSF and blood. On day 26 diagnosis was confirmed by detection of CMV-specific intrathecal IgG production. The patient was treated with ganciclovir, anti-CMV immunoglobulins and intrathecal beta interferon. He recovered completely after 2 months. Our data demonstrate the usefulness of ISH and PCR in the early diagnosis of CMV encephalitis and perhaps may encourage the use of intrathecal beta interferon in other patients with this disease.

Viral culture and p24 antigenemia of human immunodeficiency virus (HIV)-infected individuals correlated with antibody profiles determined with recombinant polypeptides of all HIV-1 open-reading frames

The association between viral activity and antibody profiles was investigated in 202 individuals infected by the human immunodeficiency virus (HIV) grouped according to their Walter Reed clinical stage. Each study group was subdivided into subjects positive or negative for markers of active viral replication: presence of serum p24 antigen and viral culture. In Western blots using recombinant antigens, sera of HIV-positive individuals with positive viral markers had a significantly lower antibody reactivity to several viral proteins than did individuals without viral markers. Noticeably, proteins of the gag (p24, p17) and env (gp120, COOH-terminal part of gp41) open-reading frames revealed a decreased reactivity. The antibody response to the regulatory proteins revealed no or poor association with viral activity in the host. The results suggest that seroreactivity is mainly influenced by factors reflecting the viral activity of an HIV-infected individual, while the clinical stage of the patient is less important. Especially, reductions in antibodies against gp120 and p17 were useful markers associated with increased viral activity.

Case management in rural areas. Definition, clients, financing, staffing, and service delivery issues

How does case management in rural areas differ from that in urban areas? How does the informal system of family, church, neighbors, and volunteers affect case management in rural areas? What are the strengths and problems of rural case management? The authors report the attitudes of rural case managers and attendees at a conference sponsored by two homecare organizations to these and other questions related to rural case management.

Cleavage and purification of prokaryotically expressed HIV gag and env fusion proteins for detection of HIV antibodies in the ELISA

Parts of the gag p24 and the gp41 transmembrane protein of the human immunodeficiency virus HIV-1 were expressed as fusion proteins in Escherichia coli, using an expression vector carrying aa 1-375 of the lac-Z gene linked to the recognition sequence for the blood coagulation factor Xa. Fusion proteins were cleaved into the bacterial and viral portion and the viral polypeptide was purified by a molecular sieve column. The purified viral antigens were tested with 288 human sera in the enzyme-linked immunosorbent assay (ELISA) technique. Comparison with commercially available tests showed comparable sensitivity and a higher specificity of the gag/env-ELISA for borderline reactive sera.

Prokaryotic expression of the major capsid protein of human cytomegalovirus and antigenic cross-reactions with herpes simplex virus type 1

The major capsid protein (MCP) of human cytomegalovirus (HCMV) was expressed in three portions as beta-galactosidase fusion proteins, covering about 75% of the open reading frame (ORF). Fusion protein SH 1 contained nucleotides 101 to 1243 of the ORF, fusion protein FS 1 contained nucleotides 1944 to 3089 and fusion protein SS 1 covered nucleotides 2624 to 3793. The recombinant proteins were tested for their immunoreactivity with human sera. Fusion protein FS 1 was found to represent the immunodominant region. The recombinant proteins were used to generate polyvalent rabbit antisera to investigate cross-reactivities with the major capsid protein (VP5) of herpes simplex virus type 1 (HSV-1). A monospecific antiserum raised against the fusion protein close to the N terminus of the MCP, as well as a monoclonal antibody and a monospecific rabbit antiserum directed against the viral MCP, cross-reacted with the VP5 as shown by immunoblotting and immunofluorescence. In order to detect common epitopes of the major capsid proteins of HCMV and HSV-1, the recombinant proteins were conjugated to CNBr-activated Sepharose and taken for purification of MCP antibodies from HCMV and HSV-1 seropositive individuals. Using this affinity chromatography method, cross-reactivity could be observed with HCMV- and HSV-positive human antisera in immunoblot experiments.

Two substrate sites in the renal Na(+)-D-glucose cotransporter studied by model analysis of phlorizin binding and D-glucose transport measurements

Time courses of phlorizin binding to the outside of membrane vesicles from porcine renal outer cortex and outer medulla were measured and the obtained families of binding curves were fitted to different binding models. To fit the experimental data a model with two binding sites was required. Optimal fits were obtained if a ratio of low and high affinity phlorizin binding sites of 1:1 was assumed. Na+ increased the affinity of both binding sites. By an inside-negative membrane potential the affinity of the high affinity binding site (measured in the presence of 3 mM Na+) and of the low affinity binding site (measured in the presence of 3 or 90 mM Na+) was increased. Optimal fits were obtained when the rate constants of dissociation were not changed by the membrane potential. In the presence of 90 mM Na+ on both membrane sides and with a clamped membrane potential, KD values of 0.4 and 7.9 microM were calculated for the low and high affinity phlorizin binding sites which were observed in outer cortex and in outer medulla. Apparent low and high affinity transport sites were detected by measuring the substrate dependence of D-glucose uptake in membrane vesicles from outer cortex and outer medulla which is stimulated by an initial gradient of 90 mM Na+ (out greater than in). Low and high affinity transport could be fitted with identical Km values in outer cortex and outer medulla. An inside-negative membrane potential decreased the apparent Km of high affinity transport whereas the apparent Km of low affinity transport was not changed. The data show that in outer cortex and outer medulla of pig high and low affinity Na(+)-D-glucose cotransporters are present which contain low and high affinity phlorizin binding sites, respectively. It has to be elucidated from future experiments whether equal amounts of low and high affinity transporters are expressed in both kidney regions or whether the low and high affinity transporter are parts of the same glucose transport molecule.

Case management in rural areas: definition, clients, financing, staffing, & service delivery issues

Case management is one method for helping persons obtain needed health and social services while maximizing available community resources. How do needed case management services differ between rural and urban areas?

The provision of home health care services through health maintenance organizations

The vast majority of the HMOs responding to the survey in this study use home health care as a substitute for acute inpatient hospitalization, contract out for services with community-based home health agencies, reimburse on a discounted fee-for-service basis, and use prior authorization and concurrent review as the primary methods to control the use of home health care. These findings suggest that HMO home health care services mirror the inadequacies of Medicare home health care in that they are acute care-focused and not intended to fill the supportive and maintenance care needs of the chronically ill elderly. HMOs, however, are typically more flexible in their service provision than is Medicare. Need for home health care is determined primarily on prospective, case-by-case evaluations of cost effectiveness, not on retrospective determinations based on strict, and sometimes arbitrary, guidelines and limitations. This, however, does raise some important issues for access and quality and for the relationship between HMOs and home health agencies. Is cost containment the only legitimate reason for providing home health care? Should home health care be used solely as a substitute for acute inpatient hospitalization? Where does the locus of authority lie for deciding coverage of home health care services? This study uncovered several issues related to the provision of home health care in HMOs that created conflict and uncertainty for all parties. These issues included: conflicting roles for HMOs, whether to provide services internally or externally, contracting between HMOs and home health agencies, the locus of authority for utilization review, the role of physicians, quality assurance, and perceived problems with the Health Care Financing Administration. HMOs are often perceived as failing to do an adequate job of providing home health care services because of the difficulty in satisfying conflicting considerations in three key areas: whether home health care should be focused on cost containment or meeting unmet needs, whether home health care should be focused on acute or long term care, and the unrealistic expectations patients and providers have of HMOs. HMOs primarily provide home health care in an effort to contain costs, particularly by using home health care to substitute for inpatient hospitalization. While HMO representatives acknowledge the importance of home health care in improving the patient's and family's quality of life by providing supportive or chronic maintenance care, the use of home health care for this purpose is generally not allowed by HMOs.(ABSTRACT TRUNCATED AT 400 WORDS)

Monoclonal antibodies against the renal Na+-D-glucose cotransporter. Identification of antigenic polypeptides and demonstration of functional coupling of different Na+-cotransport systems

Eight monoclonal antibodies are described which are directed against the renal Na+-D-glucose cotransporter. In porcine renal brush-border membranes, the antibodies either bind to one or to three polypeptides which have been identified as components of the Na+-D-glucose cotransporter (Neeb, M., Kunz, U., and Koepsell, H., (1987) J. Biol. Chem. 262, 10718-10727). Their molecular weights and isoelectric points are 75,000 and pH 5.5, 60,000 and pH 5.2, and 47,000 and pH 5.4. Six antibodies were able to influence Na+-dependent D-glucose uptake and/or Na+-dependent high affinity phlorizin binding. In the presence of Na+, the binding of all antibodies to native membrane proteins was altered by D-glucose but not by D-mannose. Since this effect was observed with D-glucose concentrations less than 1 x 10(-8) M, a high affinity D-glucose-binding site on the D-glucose transporter has been implied. Some of the antibodies probably interact also with other Na+-coupled transporters since their binding was altered by micromolar concentrations of L-lactate, L-alanine, or L-glutamate but not by the nontransported control substances D-alanine and D-glutamate. L-lactate increased the binding of one antibody in the absence but not in the presence of D-glucose. Effects of L-lactate and L-alanine on the binding of another antibody were only observed when D-glucose was present. Thus, some epitopes on the Na+-D-glucose cotransporter are altered by D-glucose and also by substrates of other Na+ cotransporters. This finding suggests functional coupling of different Na+-cotransport systems.

Reconstitution and partial purification of several Na+ cotransport systems from renal brush-border membranes. Properties of the L-glutamate transporter in proteoliposomes

Brush-border membranes of renal proximal tubules were solubilized with deoxycholate and some proteins were separated and incorporated into proteoliposomes by a reconstitution procedure which was analyzed in detail. The proteoliposomes contained mainly polypeptides with molecular weights of 152,000, 94,000, and 52,000, each of which could be separated further into homologous polypeptides with different isoelectric points. In the proteoliposomes, Na+ cotransport systems for D-glucose, acidic and neutral amino acids, and mono- and dicarboxylic acids were demonstrated by showing that due to an inwardly directed Na+ gradient the substrate concentrations in the proteoliposomes increased significantly over their respective equilibrium values. Using inhibition experiments, selectivity of the different transporters could be demonstrated. Studying the reconstituted L-glutamate transporter in detail, countertransport of L-glutamate and K+ was shown (i) at Na+ equilibrium the intraliposomal L-glutamate concentration increased significantly over the equilibrium value if an outside-directed K+ gradient was applied; (ii) Rb+ influx was significantly stimulated by the outflux of L-glutamate. By applying a K+ diffusion potential across the liposomal membrane by addition of valinomycin it could be shown that during L-glutamate transport in the presence of Na+ and K+ positive charge is transferred together with L-glutamate and Na+. The apparent Km value of L-glutamate uptake driven by concentration differences of 89 mM Na+ (out greater than in) and 89 mM K+ (in greater than out) was 26.3 +/- 1.3 microM. The Vmax value of 70.2 +/- 2.3 pmol X mg of protein-1 X S-1 was half the value measured in intact membranes.