Characterization and species distribution of high affinity GTP-coupled receptors for human rantes and monocyte chemoattractant protein 1.

Equilibrium binding studies with recombinant human chemoattractant cytokines Rantes and monocyte chemoattractant protein 1 (MCP-1) on monocytic THP-1 cells have allowed the functional identification of two distinct receptors for C-C chemokines. One is a novel oligospecific receptor with high affinity for Rantes (50% maximal inhibitory concentration [IC50], 0.68 nM) and low affinity (IC50, 35 nM) for MCP-1, while the other is the previously described specific receptor for MCP-1 (IC50, 0.5 nM). Receptor affinity for Rantes is enhanced on preparation of isolated membranes with a 12-fold decrease in receptor Kd. The basis of this enhancement is not understood. The Rantes receptor appears to be G protein linked, as binding activity is abolished by guanosine 5'-O-(3-thiotriphosphate) (IC50, 7.3 nM). In contrast to the consequences of MCP-1 binding, we were unable to demonstrate ligand-dependent calcium fluxes on binding of Rantes to human monocytes or THP-1 cells. The binding of Rantes and MCP-1 to mononuclear cells from dog, rabbit, and rat were tested. While high affinity binding could be demonstrated in dog and rabbit, differences in ligand-induced Ca2+ fluxes could be shown between species. This suggests that receptor-ligand interactions and receptor coupling is best examined with autologous receptors and cytokine.

I-E+ nonobese diabetic mice develop insulitis and diabetes.

The development of type I diabetes in the nonobese diabetic (NOD) mouse is under the control of multiple genes, one or more of which is linked to the major histocompatibility complex (MHC). The MHC class II region has been implicated in disease development, with expression of an I-E transgene in NOD mice shown to provide protection from insulitis and diabetes. To examine the effect of expressing an I-E+ or I-E- non-NOD MHC on the NOD background, three I-E+ and three I-E- NOD MHC congenic strains (NOD.H-2i5, NOD.H-2k, and NOD.H-2h2, and NOD.H-2h4, NOD.H-2i7, and NOD.H-2b, respectively) were developed. Of these strains, both I-E+ NOD.H-2h2 and I-E- NOD.H-2h4 mice developed insulitis, but not diabetes. The remaining four congenic strains were free of insulitis and diabetes. These results indicate that in the absence of the NOD MHC, diabetes fails to develop. Each NOD MHC congenic strain was crossed with the NOD strain to produce I-E+ and I-E- F1 mice; these mice thus expressed one dose of the NOD MHC and one dose of a non-NOD MHC on the NOD background. While a single dose of a non-NOD MHC provided a large degree of disease protection to all of the F1 strains, a proportion of I-E+ and I-E- F1 mice aged 5-12 mo developed insulitis and cyclophosphamide-induced diabetes. When I-E+ F1 mice were aged 9-17 mo, spontaneous diabetes developed as well. These data are the first to demonstrate that I-E+ NOD mice develop diabetes, indicating that expression of I-E in NOD mice is not in itself sufficient to prevent insulitis or diabetes. In fact, I-E- F1 strains were no more protected from diabetes than I-E+ F1 strains, suggesting that other non-NOD MHC-linked genes are important in protection from disease. Finally, transfer of NOD bone marrow into irradiated I-E+ F1 recipients resulted in high incidences of diabetes, indicating that expression of non-NOD MHC products in the thymus, in the absence of expression in bone marrow-derived cells, is not sufficient to provide protection from diabetes.

Autoimmune syndromes in major histocompatibility complex (MHC) congenic strains of nonobese diabetic (NOD) mice. The NOD MHC is dominant for insulitis and cyclophosphamide-induced diabetes.

The development of autoimmune diabetes in the nonobese diabetic (NOD) mouse is controlled by multiple genes. At least one diabetogenic gene is linked to the major histocompatibility complex (MHC) of the NOD and is most likely represented by the two genes encoding the alpha and beta chains of the unique NOD class II molecule. Three other diabetogenic loci have recently been identified in the NOD mouse and are located on chromosomes 1, 3, and 11. In addition to the autoimmune diabetes which is caused by destruction of the insulin-producing beta cells in the pancreas, other manifestations of autoimmunity are seen in the NOD mouse. These include mononuclear cell inflammation of the submandibular and lacrimal glands, as well as the presence of circulating autoantibodies. To determine the effect of the non-MHC diabetogenic genes on the development of autoimmunity, we constructed the NOD.B10-H-2b (NOD.H-2b) strain, which possesses the non-MHC diabetogenic genes from the NOD mouse, but derives its MHC from the C57BL/10 (B10) strain. The NOD.H-2b strain does not develop insulitis, cyclophosphamide-induced diabetes, or spontaneous diabetes. It does, however, develop extensive lymphocytic infiltrates in the pancreas and the submandibular glands that are primarily composed of Thy 1.2+ T cells and B220+ B cells. In addition, autoantibodies are present in NOD.H-2b mice which recognize the "polar antigen" on the insulin-secreting rat tumor line RINm38. These observations demonstrate that the non-MHC genes in the NOD strain, in the absence of the NOD MHC, significantly contribute to the development of autoimmunity. The contribution of a single dose of the NOD MHC to autoimmunity was assessed with a (NOD x NOD.H-2b)F1 cross. Although only approximately 3% of F1 females developed spontaneous diabetes, approximately 50% of both female and male F1 mice developed insulitis, and 25% of females and 17% of males became diabetic after treatment with cyclophosphamide. These data demonstrate that the MHC-linked diabetogenic genes of the NOD mouse are dominant with decreasing levels of penetrance for the following phenotypes: insulitis greater than cyclophosphamide-induced diabetes greater than spontaneous diabetes.

Voltage-gated potassium channels regulate calcium-dependent pathways involved in human T lymphocyte activation.

The role that potassium channels play in human T lymphocyte activation has been investigated by using specific potassium channel probes. Charybdotoxin (ChTX), a blocker of small conductance Ca(2+)-activated potassium channels (PK,Ca) and voltage-gated potassium channels (PK,V) that are present in human T cells, inhibits the activation of these cells. ChTX blocks T cell activation induced by signals (e.g., anti-CD2, anti-CD3, ionomycin) that elicit a rise in intracellular calcium ([Ca2+]i) by preventing the elevation of [Ca2+]i in a dose-dependent manner. However, ChTX has no effect on the activation pathways (e.g., anti-CD28, interleukin 2 [IL-2]) that are independent of a rise in [Ca2+]i. In the former case, both proliferative response and lymphokine production (IL-2 and interferon gamma) are inhibited by ChTX. The inhibitory effect of ChTX can be demonstrated when added simultaneously, or up to 4 h after the addition of the stimulants. Since ChTX inhibits both PK,Ca and PK,V, we investigated which channel is responsible for these immunosuppressive effects with the use of two other peptides, noxiustoxin (NxTX) and margatoxin (MgTX), which are specific for PK,V. These studies demonstrate that, similar to ChTX, both NxTX and MgTX inhibit lymphokine production and the rise in [Ca2+]i. Taken together, these data provide evidence that blockade of PK,V affects the Ca(2+)-dependent pathways involved in T lymphocyte proliferation and lymphokine production by diminishing the rise in [Ca2+]i that occurs upon T cell activation.

Linkage on chromosome 3 of autoimmune diabetes and defective Fc receptor for IgG in NOD mice.

A congenic, non-obese diabetic (NOD) mouse strain that contains a segment of chromosome 3 from the diabetes-resistant mouse strain B6.PL-Thy-1a was less susceptible to diabetes than NOD mice. A fully penetrant immunological defect also mapped to this segment, which encodes the high-affinity Fc receptor for immunoglobulin G (IgG), Fc gamma RI. The NOD Fcgr1 allele, which results in a deletion of the cytoplasmic tail, caused a 73 percent reduction in the turnover of cell surface receptor-antibody complexes. The development of congenic strains and the characterization of Mendelian traits that are specific to the disease phenotype demonstrate the feasibility of dissecting the pathophysiology of complex, non-Mendelian diseases.

Beta 2-microglobulin-deficient NOD mice do not develop insulitis or diabetes.

The role of CD8+ T-cells in the development of diabetes in the nonobese diabetic (NOD) mouse remains controversial. Although it is widely agreed that class II-restricted CD4+ T-cells are essential for the development of diabetes in the NOD model, some studies have suggested that CD8+ T-cells are not required for beta-cell destruction. To assess the contribution of CD8+ T-cells to diabetes, we have developed a class of NOD mouse that lacks expression of beta 2-microglobulin (NOD-B2mnull). NOD-B2mnull mice, which lack both class I expression and CD8+ T-cells in the periphery, not only failed to develop diabetes but were completely devoid of insulitis. These results demonstrate an essential role for CD8+ T-cells in the initiation of the autoimmune response to beta-cells in the NOD mouse.

Treatment of Parkinson's disease with 8-alpha-amino-ergoline, CU 32-085.

8-alpha-amino-ergoline (CU 32-085) is a dopamine receptor agonist that should have fewer side effects than most other dopamine agonists. We studied the effect of this drug in 19 parkinsonian patients. In untreated or levodopa-treated patients, there was considerable improvement of akinesia, rigidity, and tremor; on-off symptoms also improved in the levodopa-treated patients. In patients pretreated with levodopa/bromocriptine, about half the dose of CU 32-085 was necessary to obtain the same therapeutic results, but there was no further improvement of on-off symptoms. Side effects were less pronounced than with bromocriptine; no circulatory disturbances and no psychotic episodes were observed.

Primary and secondary involvement of the CNS in HIV infection.

The neurologic sequelae of human immunodeficiency virus (HIV) infection may be divided into primary (= HIV-induced) and secondary (= opportunistic infections and malignancies) manifestations. Our experience with 215 HIV-infected patients indicates that major clinical symptoms are due to a few, albeit important, neurologic diseases, although in a given patient rare and sometimes multiple complications have to be considered. The clinical features of acquired immunodeficiency syndrome (AIDS) encephalopathy and CNS toxoplasmosis that represent the major primary and secondary neurologic manifestations of AIDS are discussed in detail.

Long-term experience with bromocriptine in advanced parkinsonism. Results after one year's treatment.

The long-term effects of bromocriptine as an adjuvant were investigated in 32 patients (20 male, 12 female), aged 43-76 years (mean 65.4), suffering from parkinsonism for 3-20 years (mean 9.3). Patients were pretreated with levodopa/decarboxylase inhibitor for 24-116 months (mean 74.9). Bromocriptine was given because of a decline in the response to levodopa, various kinds of "on-off" phenomena, and disabling dyskinesias. Levodopa was reduced by 18%, while bromocriptine was added with a mean dose of 29 mg. The results showed a marked tremor and rigidity response, clearly greater than that of bradykinesia of the hands. The improvement after 4 weeks of bromocriptine treatment was maintained over 12 months. Only gait disturbances tended to increase. At the same time the self-ratings of the patients showed an increase in disability as far as daily activities were concerned. Likewise, the "on-off" symptoms with regard to the wearing-off effects worsened in comparison with the condition during the 4-week period. Akinesia paradoxica was never definitely influenced. An increase in dyskinesias was avoided and serious side-effects could be kept under control.

Neurological complications in AIDS.

Neurological complications in the acquired immunodeficiency syndrome (AIDS) are an important aspect of this new infectious disease and occur frequently. The existence of neurotropic variants of the human immunodeficiency virus (HIV), the causative agent of AIDS, is probable. Direct infection of the nervous system with HIV leads to a variety of HIV-induced neurological syndromes, the AIDS dementia complex being its most important representative. In addition, a large number of opportunistic infections and malignancies of the nervous system may complicate the disease. Major aspects of the clinical pictures, rational diagnostic approaches and treatment options of the most important sequels of HIV infection of the nervous system are discussed.

Transcranial Doppler sonographic studies of cerebral autoregulation in Shy-Drager syndrome.

A study is reported of mean arterial blood pressure and heart rate in four patients suffering from Shy-Drager syndrome. Blood flow velocity in the middle cerebral artery (MCA) was recorded by transcranial Doppler sonography. Concomitant changes in cerebral blood flow and the effect of cerebral autoregulation were thus examined. During tilt (60 degrees, head up) mean arterial blood pressure decreased by 40 mm Hg or 35%, while MCA blood flow velocity dropped by 14 cm/s or 28% (mean values). The lower percentage reduction in flow velocity may indicate a preserved cerebral autoregulation in central autonomic insufficiency.

Interleukin-2, soluble interleukin-2-receptor, neopterin, L-tryptophan and beta 2-microglobulin levels in CSF and serum of patients with relapsing-remitting or chronic-progressive multiple sclerosis.

Cerebrospinal fluid (CSF) and serum levels of interleukin-2 (IL-2), soluble IL-2 receptors (sIL-2R), neopterin, L-tryptophan (L-TRP) and beta 2-microglobulin (beta 2-M) were measured in 31 untreated multiple sclerosis patients in acute exacerbation and 27 normal controls. Twenty-six patients showed the relapsing-remitting type of disease (RRMS); 5 had a chronic-progressive course (CPMS). No changes in serum IL-2 and sIL-2R were found between RRMS patients and controls, whereas serum and CSF levels as well as the CSF/serum ratio of neopterin were significantly elevated in the RRMS group. IL-2 was not detectable in CSF of patients or controls and sIL-2R levels were at the level of the lower detection (LD) sensitivity of the ELISA method. Four of 23 RRMS patients versus 1 of 25 controls showed CSF sIL-2R levels above the LD sensitivity, indicating a trend towards elevation in acute relapse. No difference was found in serum and CSF L-TRP and beta 2-M of patients and controls. In CSF of RRMS patients neopterin and L-TRP correlated negatively, reflecting the interferon-gamma mediated activation of macrophages in acute relapse. A significant positive correlation (Spearman rank 0.57, P = 0.001) between serum IL-2 levels and duration of acute relapse (mean 30 days) warrants further evaluation.

Cerebral atrophy and long-term response to levodopa in Parkinson's disease.

In 92 parkinsonian patients (42 men, 50 women) aged from 37-79 years (mean 62.8) the impact of cerebral atrophy as assessed by computed tomography on the course of the clinical symptomatology under levodopa during a period of 1 to 5 years was investigated. It could be shown that patients suffering from medium to severe degrees of atrophy-independent of its special location--have a less favorable response than those with normal CT findings. The data do not allow a definite decision whether cortical artrophy or ventricular enlargement are of major importance. At any rate, the width of the third ventricle seems to have no influence on the course of the clinical symptoms. After 3 years of levodopa treatment a dissociation between cerebral atrophy and therapeutic effectiveness can be observed.

Three-year observation of mesulergine (CU 32-085) in advanced and newly treated parkinsonism.

In 15 patients (8 men, 7 women), aged 44-81 years, with idiopathic parkinsonism, the effects of mesulergine (CU 32-085) were observed for up to 3 years. Of these patients, four had been without previous levodopa treatment, five had been on levodopa/decarboxylase inhibitor for 6.4 years and six patients had been on levodopa/decarboxylase inhibitor and bromocriptine for a period of 7.5 years. Mesulergine proved to be effective in all three groups of patients and for each main symptom of the disease. Rigidity and tremor showed a better response than akinesia. A decline in efficacy could be observed after 18 months of treatment. By increasing the levodopa dosage, the worsening of the symptomatology could be reduced again and after 3 years patients were slightly better off than before the introduction of mesulergine. Fine motor performance showed a longer-lasting improvement than walking, which was affected by an increase of freezing. Mesulergine was not fully sufficient when given in monotherapy and the levodopa saving effect was only temporary. Parallel with the decline in the therapeutic response as assessed by the rating scales, there was a worsening in the on/off symptomatology. The on/off symptoms, evaluated by patients themselves, had shown very small or no improvement at the beginning of mesulergine administration, contrasting with the findings reflected in the assessment scales. The most frequent side-effects were hallucinations and dyskinesias. Orthostatic hypotension did not prove a problem. Dyskinesias were not seen during monotherapy with mesulergine in de novo patients.

Relationship between arteriosclerosis and cerebral atrophy in Parkinson's disease.

Computed tomographic examinations of parkinsonian patients revealed a high incidence of cerebral atrophy, in most cases a combination of cortical atrophy and ventricular enlargement. The present study considered the relationship between cerebral atrophy and physical signs indicating or promoting arteriosclerosis such as overweight, electrocardiographic changes, hypertension, calcification of the internal carotid artery and aorta as well as elongation of the aorta. The study is based on 173 treated and untreated parkinsonian patients (89 men, 84 women) aged from 37--84 years (mean 64.6), on whom CT was performed about 5.4 years after the onset of the first symptoms of the illness. The results demonstrate an increase of pathological CT findings as well as of calcification in the carotid siphon with advanced age. No correlation was found between the other items and increasing age. Further analysis of the relationship between cerebral atrophy and signs of arteriosclerosis revealed only a statistically relevant correlation with calcification of the carotid siphon, especially with calcification of the media. Since pathological CT findings and calcification of the internal carotid artery are both related to advanced age, whereas all the other items which may be considered to be indications of arteriosclerosis do not have any clear relationship, it is concluded that the cerebral atrophy in Parkinson's disease is not caused by arteriosclerosis.

The significance of cerebral atrophy for the symptomatology of Parkinson's disease.

Hitherto published results on the impact of brain atrophy on the neurological and psychopathological sympion of this problem without risk of complications. We investigated 173 parkinsonian patients (89 men, 84 women) aged 37--83 years. Besides CT in all patients a standardized neurological and psychopathological investigation was carried out, including psychological tests, intelligence, personality structure, fine motor performance and visual reaction times. The investigations revealed pronounced correlations between CT-findings and more severe clinical symptomatology and a corresponding impairment in daily activities in the levodopa-treated and particularly in the untreated group, above all when there was a combination of cortical atrophy and ventricular enlargement. The same was true for fine motor performance and simple and complex reaction times. These functions were more impaired in patients with brain atrophy, irrespective of its localisation, whether cortical atrophy or ventricular enlargement. In contrast, no statistically significant relationship between the different parameters of brain atrophy and intelligence could be found. Considering cortical atrophy as a specific sign in Parkinson's disease -- our results are in favour of this assumption -- and ventricular enlargement more related to increasing age, parkinsonism is influenced by extranigral lesions inherent in the disease and dependent on increasing age.

Treatment strategies in Parkinson's disease after a quarter century experiences with L-DOPA therapy.

Parkinson's disease is treated in relation to its symptoms and stage in any individual plan of therapy. L-Dopa treatment is the most effective method of therapy and there is no evidence that would prohibit the early application of L-Dopa. The side-effects and motor complications during long-term L-Dopa treatment have led to give preference to combinations of L-Dopa with other anti-Parkinsonian agents. It is still controversial as to which combination of agents sould be used and whether L-Dopa long-term problems demand the initial introduction of a combination therapy. Another open question is whether neuroprotection is possible in Parkinson's disease with the drugs currently available. In advanced stages of Parkinson's disease treatment of concomitand mental symptoms and multifarious disorders of the autonomic nervous system are becoming of increasing significance.

Therapeutic efficacy of R-(-)-deprenyl as adjuvant therapy in advanced parkinsonism.

To quantify the clinical benefit of an additional deprenyl administration in L-dopa pretreated patients we have performed a study of 30 patients suffering from advanced parkinsonism. During the first phase of the study over three months under controlled conditions deprenyl showed in a cross-over design a similar therapeutic potential as the control-substance methixene, but it was markedly better tolerated. The therapeutic effect persisted over a follow-up observation period of 1 year with only a slight tendency to deterioration. There was no marked positive influence on fluctuations, only end-of-dose akinesia improved slightly. The substance was well tolerated by the patients, the frequency of side effects was less than under methixene. In contrast to the good clinical improvement there was only a slight reduction in depression score. Thus the therapeutic effect seems not only to be mediated by a nonspecific antidepressant effect. The most remarkable advantage of deprenyl compared to other substances in adjuvant therapy of advanced parkinsonism is probably the reduction of serious side effects.

Fluctuations in Parkinson's disease. Pathogenetic significance of levodopa's cerebral pharmacokinetics and pharmacodynamics.

The pathogenetic mechanisms which are responsible for the clinical manifestation of motor-fluctuations are poorly understood. Peripheral pharmacokinetics do obviously not play a significant role. For a better understanding of fluctuations exact knowledge and precise characterization of the levodopa induced motor-response (MR) might be useful. In a number of studies it has been demonstrated that this MR follows the "all or none" rule after a levodopa threshold concentration has been exceeded. Such a threshold is considered to exist in the plasma-compartiment as well as in the cerebral effect-compartiment. The specific character of the MR can be modified by the coadministration of dopamine-agonists. Dopamine-agonists lower the levodopa threshold and they reduce the time-lag between levodopa plasmaconcentration and MR. The duration of the MR can be prolonged but the intensity (amplitude) of the MR cannot be augmented. Most of these data to levodopa pharmacodynamics can be explained by a model which is presented in this paper and which is mainly based on cerebral pharmacokinetic mechanisms.

Pharmacodynamics of levodopa coadministered with apomorphine in parkinsonian patients with end-of-dose motor fluctuations.

The modification of the pharmacodynamic response to a single oral dose of levodopa/benserazide by the coadministration of the dopamine agonist apomorphine was investigated in parkinsonian patients with end-of-dose motor fluctuations. The relation between levodopa plasma concentrations and motor response was examined in a double-blind, randomized, crossover design in 10 patients with idiopathic Parkinson's disease with end-of-dose motor fluctuations. Oral single-dose challenges with 100 mg of levodopa/25 mg of benserazide were carried out twice in each patient, under coadministration with apomorphine (1 mg/h) or 0.9% saline (placebo) subcutaneously. The sum scores (sigma score) of the Columbia University Rating Scale (CURS) were used as effect parameters for pharmacodynamic assessment. A sigmoidal Emax model was fitted to the data using a semiparametric pharmacokinetic-pharmacodynamic approach. Levodopa pharmacokinetics were not significantly modified by the coadministration of apomorphine. The area under the curve was 1599 +/- 615 ng.ml-1 h. (levodopa + saline) and 1821 +/- 625 ng.ml-1.h (levodopa + apomorphine). Cmax was 1094 +/- 476 ng.ml-1 (levodopa + saline) and 1129 +/- 435 ng.ml-1 (levodopa + apomorphine). Under both experimental regimens, the maximum clinical response to levodopa (Emax) yielded a decrease in the CURS sigma rating of about 20 score points. Estimates of the EC50 of levodopa decreased significantly from 430 +/- 163 ng.ml-1 (levodopa + saline) to 315 +/- 123 ng+ml-1 (levodopa + apomorphine) (95% confidence interval [CI] 0.51 -0.98, point estimator 0.75). The mean duration of the motor response rose from 1.9 +/- 0.5 h (levodopa + saline) to 3.0 +/- 0.9 h (levodopa + apomorphine (95% CI 1.23 to 2.06, point estimator 1.60). Thus, a reduction of the threshold levels for levodopa (EC50) was accompanied by approximately 50% gain in on-phase duration, but not in an increased magnitude of the motor response (Emax).