Mobilization of intracellular calcium stores participates in the rise of [Ca2+]i and the toxic actions of the HIV coat protein GP120

The HIV envelope glycoprotein, GP120, increases intracellular Ca2+ concentration and induces degeneration of human and animal neurons in culture. Using patch-clamp recordings and Ca2+ imaging techniques, we have now examined the contribution of intracellular stores of calcium in the effects of GP120. We report that in rat hippocampal neuronal cultures, GP120 induces a dramatic and persistent increase in [Ca2+]i which is prevented by drugs that either deplete (caffeine, carbachol, thapsigargin) or block (dantrolene) Ca2+ release from intracellular stores. In contrast, N-methyl-d-aspartate (NMDA) receptors or voltage-dependent calcium channels do not participate in these effects, as: (i) the increase in [Ca2+]i was not affected by NMDA receptor antagonists or calcium channel blockers; and (ii) and GP120 did not generate any current in whole-cell recording. Dantrolene, a ryanodine stores inhibitor, also prevented neuronal death induced by GP120. Our results show that the GP120-induced rise in [Ca2+]i originates from intracellular calcium stores, and suggest that intracellular stores of calcium may play a determinant role in the pathological actions of GP120.     

Immunohistochemical localization of NMDA- and AMPA-type glutamate receptor subunits in the basal ganglia of red-eared turtles

Corticostriatal and thalamostriatal projection systems have been shown to utilize glutamate as a neurotransmitter in mammals and birds. Although corticostriatal and thalamostriatal projection systems have been demonstrated in turtles, it is uncertain whether they too use glutamate as their neurotransmitter. Immunohistochemical localization of glutamate and of NMDA- and AMPA-type ionotropic glutamate receptor subunits (NMDAR2A/B, GluR1, GluR2/3, and GluR4) were used to address this issue. Numerous medium-sized neurons that were rich in NMDAR2A/B and GluR2/3 were observed in the striatal part of the basal ganglia of red-eared turtles. Smaller numbers of medium-sized neurons and some large neurons rich in the GluR1 and GluR4 subunits were also observed in the striatum. The striatal neuropil was notably rich in GluR1, GluR2/3 and NMDAR2A/B subunits. The pallidal region was specifically rich in large neurons possessing GluR4 subunits. Consistent with the glutamate receptors on striatal and pallidal neurons, sources of input to the striatum and pallidum in turtle such as the dorsomedial and dorsolateral thalamic nuclei (which appear to correspond to intralaminar thalamic nuclei), telencephalic pallial cell groups, and the apparent subthalamic nucleus homologue were rich in glutamatergic neurons. The results show that the thalamostriatal, corticostriatal and subthalamo-pallidal projection systems of turtles are glutamatergic and that similar basal ganglia cell types in turtles and mammals have largely similar glutamate receptor characteristics. Copyright (R) 2000 S.Karger AG, Basel     

Encrusted alkaline cystitis and malacoplakia

Urinary infection due to urea splitting bacteria leads to a rise in urinary pH, favouring the precipitation of calcium salts and struvita crystals. If deposited on the surface of a bladder with chronic inflammation or some other previous lesion, may produce an alkaline encrusted cystitis, now a rare condition. In the case here presented, occurred in a 69-year-old male. Corynebacterium urealyticum grown in the urine, and some foci of malakoplakia were found in the area of encrustation endoscopically excised. This case seems to be the third example of alkaline encrusted cystitis associated with malakoplakia reported in the bibliography. These two conditions share similar clinical signs and may probably have a common aetiopathogenesis.     

Ultrastructural investigation of human sperm using atomic force microscopy

Ultrastructural investigation of human sperm in its natural environment (without fixation, dehydration, embedding, sectioning, etc.) was carried out by using atomic force microscope (AFM) in its tapping mode. This technique permits the examination of fine structural details of undamaged sperm and its topography with precision. Moreover, it allows 3D reconstruction of images and enhances the contrast to resolve details such as mitochondria that surround the axoneme at the sperm middle piece. An organized structure has been found in the flageller axoneme region. Ultrastructure also reveals folding and details of the depression of the membrane that cannot be examined with conventional techniques.     

Antineoplastic effects of partially HLA-matched irradiated blood mononuclear cells in patients with renal cell carcinoma.

PURPOSE: Vaccines, cytokines, and other biologic-based therapies are being developed as antineoplastic agents. Many of these agents are designed to induce an autologous immune response directed against the malignancy. In contrast, hematopoietic stem-cell transplantation is being developed as a form of allogeneic immunotherapy. This study tests the tolerance and antineoplastic activity of sequential infusions of partially HLA-matched allogeneic blood mononuclear cells (obtained from relatives) when administered outside of the context of a hematopoietic stem-cell transplantation. The cells are irradiated to prevent graft-versus-host disease. PATIENTS AND METHODS: Fifteen patients with relapsed or refractory malignancies for which no standard therapy was available were enrolled onto a clinical trial designed to assess the tolerability and antineoplastic effects of irradiated partially HLA-matched blood mononuclear cells obtained from relatives. RESULTS: There was disease regression in three patients with metastatic renal cell carcinoma during treatment. There was disease progression in six patients with metastatic renal cell carcinoma and two patients with metastatic melanoma during treatment. There was no change in disease state in several other patients. CONCLUSION: Irradiated allogeneic blood mononuclear cells administered outside the context of hematopoietic stem-cell transplantation may induce disease responses in patients with relapsed or refractory malignancies. Transfusion of irradiated allogeneic blood mononuclear cells should be developed further as a novel therapeutic antineoplastic approach.     

Occult quinine-induced thrombocytopenia

Quinine is universally used for the very common symptom of night leg cramps. Patients may not mention it among their medicines, since it is so commonly used and they regulate it themselves. A 68-year-old man suddenly developed extensive bleeding due to severe thrombocytopenia. The diagnosis was initially thought to be a recurrence of idiopathic thrombocytopenic purpura (ITP) that had initially occurred in 1992 and had required splenectomy. Drug-induced thrombocytopenia was also considered, and he was told to stop all of his medicines. Only after three subsequent episodes of severe, symptomatic thrombocytopenia over the next four weeks did he say, upon repeat questioning, that he had continued to take quinine for night leg cramps. Even after a strict warning, he took another quinine tablet that evening, which triggered his fifth episode of severe thrombocytopenia, and confirmed the etiology of quinine-induced thrombocytopenia. The diagnosis thrombocytopenia caused by common drugs can be difficult, requiring persistent, explicit questions.     

Indium-111 labelled white blood cell scintigraphy in cranial and spinal septic lesions

Cranial and spinal infections are severe events that require timely diagnosis and treatment. Physical and neurological examination, laboratory tests and radiological imaging may be insufficient for assessing cranial and spinal septic lesions. This study aimed to evaluate the accuracy of indium-111 white blood cell (WBC) scan in assessing the presence of leucocytes in intracranial and spinal lesions, and in the diagnosis, management and follow-up of primary, post-traumatic and post-surgical infections. One hundred and twenty-four subjects were included in the study (48 with post-traumatic or post-surgical lesions, 73 with primary cerebral lesions, and 3 with spinal lesions). All patients underwent a diagnostic work-up including planar scans with 111In-labelled WBCs, at 4 and 24 h post tracer injection. All subjects underwent surgical treatment. Patients who did not recover from the infection as suggested by clinical evolution underwent further treatment (up to three times) and further WBC scans (up to four times). WBC scintigraphy correctly identified all the areas of leucocyte accumulation, as confirmed after surgery. WBC scintigraphy also correctly excluded the presence of leucocytes in all other lesions, as demonstrated at surgery. The results of this study confirm the accuracy of WBC scan for the assessment of patients with cranial and spinal lesions, in whom the demonstration of leucocyte accumulation can ease the diagnosis of infection, and indicate that the method is also accurate for the follow-up and management of neurosurgical patients.