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Biomedical subjects

R E Schmidt

Publications and source records attributed to R E Schmidt.

At least 37 records · Page 2Linked to original sources

Direct costs for the treatment of HIV-infection in a German cohort after the introduction of HAART.

BACKGROUND: Highly active antiretroviral combination therapy (HAART) has become the standard of care for HIV infection. The reduction of morbidity by HAART has been proven to be cost-effective despite high expenditures for regular use of antiretrovirals. We examined direct costs in a German monocentric cohort of HIV-infected patients after introduction of HAART. SUBJECTS/METHODS: In 1997 recruitment started and 201 patients gave informed consent. They underwent structurized interviews. Additional data were taken from the patients records. Later on follow-ups were performed for the same cohort in the years 2000 and 2001 respectively. Direct costs have been calculated per patient and year for each period. RESULTS: The proportion of HAART treated patients rised in the cohort from 86% to 93%. The mean of antiretrovirals used per case increased from 2.4 to 3.4. Nevertheless mean direct costs for HAART decreased significantly from Euro 17,746 to Euro 16,007. Reduction of expenditures for additional drugs, hospitalisation and diagnostics led to about one third decrease of mean total direct cost from Euro 35,865 in 1997 to Euro 24,482 in 2001. For surviving patients expenditures remained higher in advanced stage of disease for HAART, hospitalisation, diagnostics and total costs. CONCLUSION: Expenditures for HAART remained on a high level. Despite rising drug prices and increased use of antiretrovirals a decrease of mean costs of HAART by about 10% resulted from more frequent use of less expensive drug combinations. The continuous decrease of expenditures for non-HAART drugs, diagnostics and hospitalisation predominated and therefore HAART caused about a half of total direct costs in 1997 and two third in 2001 respectively. Higher expenditures in advanced stages of disease continued over the follow up period and raise the question of an economic impact of earlier initiation of treatment. More extensive use of standardized evaluation of direct costs could be an important tool towards a more rational allocation of resources in health care.

Adult↗

Drug under test: influenza--Relenza in daily practice. Experience during the influenza season 1999/2000.

A total of 5-7 million cases of the disease, 4.5 million medical certificates, 25,000 admissions to hospital, 15,000 mortalities and direct and indirect costs amounting to several billions - that is the outcome of a "normal" influenza season (data provided by the Influenza Study Group, AGI, of Germany on the 1998/99 season). With zanamivir (Relenza), a selective inhibitor of the influenza-specific neuraminidase, a pharmaceutical product against influenza A and B is now available in Germany for the very first time. In clinical studies, zanamivir reduced not only the duration of the illness and the severity of symptoms, but also the rate of complications and the need for antibiotics. Under practice conditions, the efficacy and tolerability of the anti-influenza product were studied during the 1999/2000 influenza season. In a large observational study in over 1,900 patients, including many patients at risk of asthma and/or chronic obstructive bronchitis, zanamivir (Relenza) improved the symptoms quickly and reliably, and was tolerated very well. The diagnosis of influenza was established clinically to discriminate the disease from colds.

Antiviral Agents↗

[Helper cells, viral load, genetic factors, co-infections. Prognostic factors in HIV-1 infection].

The ideal time to initiate antiretroviral therapy in asymptomatic patients with chronic HIV infection remains to be defined. The most relevant laboratory parameter is the CD4 cell count. Therapy should be started before the CD4 cells drop below 200/microliter and the immune system becomes compromised. In contrast to past recommendations, viral load should not be used as a single laboratory parameter for initiation of antiretroviral therapy in asymptomatic untreated patients. The determination of genetic factors to assess the prognosis of HIV patients has not yet been incorporated into daily clinical practice. While co-infection with GBV-C is a prognostically favorable factor for the course of the HIV infection, replicative hepatitis C is associated with increased mortality.

AIDS-Related Opportunistic Infections↗

Adrenaline-induced immunological changes are altered in patients with rheumatoid arthritis.

OBJECTIVE: To investigate whether in rheumatoid arthritis (RA) patients the immunological changes induced by adrenaline are different from healthy controls (HC). METHODS: Fifteen female RA patients and 14 HC were infused with 1 micro g/kg adrenaline over 20 min. Blood was drawn before, immediately after, and 1 h after the end of infusion. Lymphocyte subpopulations, cytokine production and natural killer cell cytotoxicity were determined. RESULTS: Subjects exhibited mild cardiovascular changes with no differences between patients and controls. CD16(+)CD56(+)CD3(-) NK cells increased by a factor of 5.7, CD3(+) T cells by 1.5, monocytes by 1.6 and PMN by 1.2 in both groups. The numbers of IL-8- and IL-10-producing monocytes were higher in patients and presented a larger increase after infusion. NK cytotoxic activity was higher in RA patients and increased after infusion in both groups. Activated monocytes and T cells were preferentially recruited in patients and controls. Values returned to baseline 1 h later. CONCLUSION: We describe an altered response to adrenaline in patients with RA with both pro- and anti-inflammatory effects. Additionally, activated T cells and monocytes recruited to the peripheral blood may influence disease activity.

Adult↗

Neuronal preservation in the sympathetic ganglia of rats with chronic streptozotocin-induced diabetes.

Recent studies have reported that rat sympathetic neurons exposed to increased concentrations of glucose in vitro initiate an apoptotic program which culminates in neuronal cell death, a process proposed to contribute to the development of human diabetic autonomic neuropathy. We tested this hypothesis in an in vivo streptozotocin model of diabetic autonomic neuropathy using an unbiased counting method to quantitate neuron numbers in control and diabetic rats. Ten months of severe untreated diabetes failed to produce significant neuron loss in either the rat superior mesenteric or superior cervical sympathetic ganglia indicating that apoptotic neuronal cell death is unlikely to play a role in the pathogenesis of experimental diabetic autonomic neuropathy.

Animals↗

Prednisolone does not prevent hypersensitivity reactions in antiretroviral drug regimens containing abacavir with or without nevirapine.

OBJECTIVES: To determine the effect of adjuvant prednisolone use on the development of abacavir (ABC)- and nevirapine (NVP)-associated hypersensitivity reactions (HSR). METHODS: Randomized open-label study in antiretroviral-naive adult HIV-1 infected patients using a factorial design in which NVP and/or hydroxyurea (HU) and/or prednisolone are added to a regimen of ABC, zidovudine and lamivudine. Prednisolone (40 mg once daily) was added for the first 2 weeks of treatment. As it was difficult to distinguish ABC-associated HSR from NVP-associated HSR, these events were treated as a composite endpoint. The odds ratio (OR) of developing HSR for prednisolone-use was calculated with and without stratification by NVP and/or HU. Logistic regression was performed to identify risk factors for developing HSR. RESULTS: Of the 229 patients 115 were randomized to prednisolone and 114 to no-prednisolone; 19 (17%) and 11 (10%) patients, respectively, developed HSR. The expected prevention of HSR by prednisolone use was not observed. In fact use of prednisolone showed an increased risk for HSR although this did not reach statistical significance [OR, 1.82; 95% confidence interval (CI), 0.82-4.03]. There was a higher incidence of HSR in the NVP group than in the non-NVP group (20% versus 6%; P = 0.002). An additional risk factor identified in a multivariate logistic model was a high baseline CD4 cell count (OR, 1.26 per 100 x 10(6) cells/l increase; 95% CI, 1.06-1.51). CONCLUSIONS: The simultaneous start of ABC and NVP in first-line antiretroviral regimens should be avoided because of a high (20%) incidence of HSR. Short-term therapy with prednisolone did not prevent HSR in patients using ABC with or without NVP.

Adult↗

Infection with GB virus C and reduced mortality among HIV-infected patients.

BACKGROUND: The flavivirus GB virus C (GBV-C, also designated hepatitis G virus) was identified in a search for hepatitis viruses, but no disease is currently known to be associated with it. We investigated the relation between coinfection with GBV-C and the long-term outcome in patients infected with the human immunodeficiency virus (HIV). METHODS: A total of 197 HIV-positive patients were followed prospectively beginning in 1993 or 1994. Of these patients, 33 (16.8 percent) tested positive for GBV-C RNA, 112 (56.9 percent) had detectable antibodies against the GBV-C envelope protein E2, and 52 (26.4 percent) had no marker of GBV-C infection and were considered unexposed. We assessed the relation between GBV-C infection and the progression of HIV disease. We also tested 169 GBV-C-positive plasma samples with a quantitative branched-chain DNA (bDNA) assay in order to investigate possible correlations between GBV-C viral load and both the CD4+ cell count and the HIV load. RESULTS: Among the patients who tested positive for GBV-C RNA, survival was significantly longer, and there was a slower progression to the acquired immunodeficiency syndrome (AIDS) (P<0.001 for both comparisons). Survival after the development of AIDS was also better among the GBV-C-positive patients. The association of GBV-C viremia with reduced mortality remained significant in analyses stratified according to age and CD4+ cell count. In an analysis restricted to the years after highly active antiretroviral therapy became available, the presence of GBV-C RNA remained predictive of longer survival (P=0.02). The HIV load was lower in the GBV-C-positive patients than in the GBV-C-negative patients. The GBV-C load correlated inversely with the HIV load (r=-0.33, P<0.001) but did not correlate with the CD4+ cell count. CONCLUSIONS: Coinfection with GBV-C is associated with a reduced mortality rate in HIV-infected patients. GBV-C is not known to cause any disease, but it is possible that its presence leads to an inhibition of HIV replication. However, GBV-C infection could also be a marker for the presence of other factors that lead to a favorable HIV response.

Adult↗

Autosomal dominant Kufs' disease: a cause of early onset dementia.

Kufs' disease is the rare, adult-onset form of the neuronal ceroid-lipofuscinoses (NCL). Two clinical Kufs' phenotypes have been described, one featuring generalized tonic-clonic seizures and the other characterized by dementia. Autosomal dominant inheritance of Kufs' disease has been reported for only two families. The genetic and molecular defects underlying Kufs' disease are unknown. We report a third family with apparent autosomal dominant Kufs' disease in a family of English ancestry. Ten individuals (five men, five women) have been affected over five generations. Age of onset typically is in the fourth decade of life and is heralded by seizures. Clinical and neuropsychological assessments in several affected individuals, however, confirm the presence of dementia and follow-up evaluations suggest that dementia is the primary disabling feature of the illness. Motor abnormalities also are frequent. Neuropathological examination (three cases) documents the presence of neuronal lipopigment accumulation consistent with NCL. The combination of dementia and seizures in this and two other reported families with autosomal dominant Kufs' disease suggest that this entity represents a distinctive clinicopathological entity. Dementia is prominent but is almost always associated with generalized seizures and motoric disturbances early in the disease course. Kufs' disease should be considered in the differential diagnosis of early onset, atypical dementia.

Adult↗

Distinct tissue site-specific requirements of mast cells and complement components C3/C5a receptor in IgG immune complex-induced injury of skin and lung.

We induced the passive reverse Arthus reaction to IgG immune complexes (IC) at different tissue sites in mice lacking C3 treated or not with a C5aR-specific antagonist, or in mice lacking mast cells (Kit(W)/Kit(W-v) mice), and compared the inflammatory responses with those in the corresponding wild-type mice. We confirmed that IC inflammation of skin can be mediated largely by mast cells expressing C5aR and FcgammaRIII. In addition, we provided evidence for C3-independent C5aR triggering, which may explain why the cutaneous Arthus reaction develops normally in C3(-/-) mice. Furthermore, some, but not all, of the acute changes associated with the Arthus response in the lung were significantly more intense in normal mice than in C3(-/-) or Kit(W)/Kit(W-v) mice, indicating for C3- and mast cell-dependent and -independent components. Finally, we demonstrated that C3 contributed to the elicitation of neutrophils to alveoli, which corresponded to an increased synthesis of TNF-alpha, macrophage-inflammatory protein-2, and cytokine-induced neutrophil chemoattractant. While mast cells similarly influenced alveolar polymorphonuclear leukocyte influx, the levels of these cytokines remained largely unaffected in mast cell deficiency. Together, the phenotypes of C3(-/-) mice and Kit(W)/Kit(W-v) mice suggest that complement and mast cells have distinct tissue site-specific requirements acting by apparently distinct mechanisms in the initiation of IC inflammation.

Animals↗

The human GPI1 gene is required for efficient glycosylphosphatidylinositol biosynthesis.

The first step in glycosylphosphatidylinositol (GPI) membrane anchor biosynthesis that is defective in paroxysmal nocturnal haemoglobinuria is mediated by an N-acetylglucosaminyl transferase expressed in the endoplasmic reticulum. Six human genes encode subunits of this enzyme, namely PIG-A, PIG-C, PIG-H, PIG-P, GPI1, and DPM2. Here, the human GPI1 gene is characterised. This gene is organised into eleven exons. The locus was mapped to chromosome 16p13.3 near the haemoglobin alpha chain locus. GPI1 is expressed ubiquitously in human cells and tissues. Expression levels are markedly elevated in haematopoietic tissues (bone marrow, foetal liver). To determine whether human GPI1 is essential for human GPI biosynthesis, antisense RNA was expressed in HEK293 cells. Transfectants exhibited a marked but incomplete decrease in the expression of a GPI-linked reporter protein, confirming that GPI1 is required for efficient GPI biosynthesis. In contrast, expression of GPI-linked proteins is normal in lymphatic cell lines from individuals with the alpha thalassaemia/mental retardation syndrome, which is characterised by large deletions from chromosome 16p removing one of the two GPI1 alleles along with the haemoglobin alpha locus. In conclusion, GPI1 plays an important role in the biosynthesis of GPI intermediates. Due to its autosomal localisation, the heterozygous deletion of GPI1 does not lead to an overt defect in the expression of GPI-linked proteins.

Cell Line, Transformed↗

Pulmonary hypersensitivity reaction induced by efavirenz.

HIV-infected patients are at increased risk of developing adverse drug reactions such as a maculopapular rash due to antiretroviral drugs. For example, exanthema induced by non-nucleoside reverse transcriptase inhibitors leads to drug discontinuation in many patients. We present a patient with a severe pulmonary hypersensitivity reaction due to efavirenz.

Adult↗

Fc gamma RIII-mediated production of TNF-alpha induces immune complex alveolitis independently of CXC chemokine generation.

We recently demonstrated a codominant role of C5aR and FcgammaRIII in the initiation of IgG immune complex-mediated inflammation in mice. In this study, we investigated the relative contribution of FcgammaRIII in the generation of several cytokines during experimental hypersensitivity pneumonitis/alveolitis in vivo. Induction of immune complex-alveolitis in C57BL/6 mice resulted in strong accumulation of neutrophils into the lung and enhanced chemotactic activity within bronchoalveolar lavage fluid accompanied by an increased production of the proinflammatory cytokines TNF-alpha and IL-1beta as well as the ELR-CXC chemokines macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (KC). FcgammaRIII-deficient C57BL/6 mice (FcgammaRIII(-/-)) showed a marked reduction of the inflammatory response due to decreased production of TNF-alpha, IL-1beta, and MIP-2. Results obtained in C57BL/6 mice either lacking the TNF-alpha class I receptor (TNF-alphaRI(-/-)) or treated with neutralizing anti-TNF-alpha mAb demonstrated an essential contribution of TNF-alpha for mediating IL-1beta release, neutrophil influx, and hemorrhage. Surprisingly, MIP-2 and KC chemokine levels remained largely unaffected in TNF-alphaRI(-/-) mice or after functional inhibition of TNF-alpha. These data suggest that in immune complex alveolitis, the activation of FcgammaRIII may induce divergent downstream effector pathways with TNF-alpha acting independently of CXC chemokines to trigger the inflammatory response in C57BL/6 mice.

Alveolitis, Extrinsic Allergic↗

[The cost of an HIV patient. Lack of funds for optimal treatment?].

Many patients with HIV--a group in urgent need of effective health care measures--are extremely worried by current discussions on budgeting, fearing, as daily practice shows, restrictions on vitally indicated services. The present article describes the results of a recent health economics study of the direct and indirect costs generated by HIV infection.

Anti-HIV Agents↗

[Rehabilitation and pensioning. Social network assimilates the HIV patient poorly].

For HIV patients, the social security net contains considerable gaps; for example, more than one-half of the unemployed patients under 55 receive no pension; in the case of those who go on to develop AIDS, the figure is 30%. Apparently, recognition of inability to work depends on the severity of the disability. Nor does the statutory regulation of rehabilitation measures do justice to those infected with HIV. Despite their higher morbidity, they are under-represented by a factor of 10 in comparison with the average in the general population when it comes to medical rehabilitation. While formerly, the HIV-infected were granted a disablement pension relatively quickly, today the pension insurance carriers appear to be adopting a more restrictive attitude, and often grant a pension for only a limited period. Furthermore, the legislation took effect at the beginning of 2001, has also made early pensioning more difficult.

Disability Evaluation↗

Adjuvant arthritis induces down-regulation of G protein-coupled receptor kinases in the immune system.

G protein-coupled receptors (GPCR) play a crucial role in the regulation of the immune response by, e.g., chemokines, PGs, and beta(2)-adrenergic agonists. The responsiveness of these GPCRs is turned off by the family of G protein-coupled receptor kinases (GRK1-6). These kinases act by phosphorylating the GPCR in an agonist-dependent manner, resulting in homologous desensitization of the receptor. Although GRKs are widely expressed throughout the body, leukocytes express relatively high levels of GRKs, in particular GRK2, -3, and -6. We investigated whether in vivo the inflammatory disease adjuvant arthritis (AA) induces changes in GRK expression and function in the immune system. In addition, we analyzed whether the systemic effects of AA also involve changes in GRKs in nonimmune organs. At the peak of the inflammatory process, we observed a profound down-regulation of GRK2, -3, and -6 in splenocytes and mesenteric lymph node cells from AA rats. Interestingly, no changes in GRK were observed in thymocytes and in nonimmune organs such as heart and pituitary. During the remission phase of AA, GRK levels in spleen and mesenteric lymph nodes are returning to baseline levels. The decrease in GRK2 at the peak of AA is restricted to CD45RA(+) B cells and CD4(+) T cells, and was not observed in CD8(+) T cells. In conclusion, we demonstrate in this study, for the first time, that an inflammatory process in vivo induces a tissue-specific down-regulation of GRKs in the immune system.

Animals↗

CD56bright cells differ in their KIR repertoire and cytotoxic features from CD56dim NK cells.

In this study we present new differential characteristics of NK cells expressing CD56 surface antigen in low (CD56dim) or high (CD56bright) density. In contrast to CD56bright NK cells CD56dim cells express killer cell immunoglobulin (Ig)-like receptors (KIR) such as CD158a, CD158b, and NKB1. However, c-type lectin-like receptors (KLR) CD94/NKG2 and CD161 are present on both subsets. The ability to form conjugates with susceptible targets is approximately twice as strongly pronounced in CD56dim vs. CD56bright NK cells. Last but not least, granules of CD56dim cells contain about tenfold more perforin and granzyme A enabling potentially more effective cytolysis compared to CD56bright NK cells. On the other hand, CD56bright NK cells are superior in producing the proinflammatory cytokines IFN-gamma (28.5% vs. 20.8%, p<0.05) and TNF-alpha (28% vs. 15.8%, p<0.001). The different NK cell populations retained their specific phenotype in vitro during culture in the presence of IL-2 contradicting that they simply display different stages of maturity. Taken together our data support the view that CD56bright cells are specialized NK cells that regulate immunological response mechanisms rather by cytokine supply than by their cytotoxic potential. The poor cytolytic capacity of CD56bright NK cells can be explained by weak ability in forming conjugates with target cells and low contents of perforin and granzyme A in their granules.

Antigens, CD↗