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Journal Article 2001; 22(2): 101-108 PubMed PMID: 11335886 Citation  Keywords:  1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine:pharmacology, Animals, Apoptosis:drug effects, Brain:cytology, Cell Count, Corpus Striatum:cytology, DNA Fragmentation, Dopamine Agents:pharmacology, Male, Melatonin:pharmacology, Mesencephalon:cytology, Mice, .   

OBJECTIVES: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin that induces a Parkinsonian-type syndrome in animals which is similar to Parkinson's disease in humans. MPTP toxicity partially depends on the production of free radicals which in turn play a key role in the apoptotic death of neurons. In the present study melatonin, a potent free radical scavenger with antiapoptotic properties, was given to determine whether it would reduce oxidative stress in mice treated with MPTP.

MATERIALS AND METHODS: Male mice were given MPTP with or without melatonin and the brain was studied either 6h, 24h, 7 days or 15 days after the last MPTP injection.

RESULTS: The results show that melatonin counteracted in vivo MPTP-induced apoptosis in midbrain neurons at 6 and 24 h after MPTP treatment, and partially prevented apoptosis at 7 and 15 days after MPTP administration. MPTP treatment also produced time-dependent cell damage, whereas melatonin reduced the percentage of damaged cells at all time points, the effect being most evident at 15 days after treatment. Moreover, melatonin counteracted MPTP-dependent DNA fragmentation in the midbrain and striatum at 7 and 15 days after drug administration.

CONCLUSION: These results support a role for melatonin in protecting neurons against MPTP toxicity in vivo, and suggest that its antiapoptotic action is one of the mechanisms by which melatonin protects neuronal cells from neurotoxic insults....

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Journal Article 2001; 22(2): 93-99 PubMed PMID: 11335885 Citation  Keywords:  Alcoholism:complications, Animals, Autoradiography, Cell Division:drug effects, Ethanol:administration & dosage, Leydig Cells:drug effects, Male, Rats, Rats, Sprague-Dawley, Seminiferous Tubules:drug effects, Spermatogonia:drug effects, Testicular Disease.   

OBJECTIVES: Considering the possibility that alcoholism induces gonadal dysfunction, the present work was designed to investigate the morphophysiology of rat testes submitted to experimental alcoholism.

METHODS: Male Sprague-Dawley rats weighing 150+/-5 gm were chronically given 40% ethanol solution at a dose of 3 g/kg body weight for 30 days. (3)H-thymidine autoradiographic investigations and histological studies were carried out to determine the proliferative activity and/or different stages of spermatogenesis in the seminiferous tubule cycle and Leydig cells.

RESULTS: The 3H-thymidine autoradigraphic investigation revealed that there was a significant inhibition in the proliferative activity of the spermatogonia in all stages of the seminiferous tubule cycle in the alcohol-treated rats versus controls as indicated by the values of (3)H-labelling indices. The histological and numerical investigations indicated that the alcohol-treated rats presented testicular lesions including a significant decrease in the diameter of the seminiferous tubules, the number of different germ cells in all stages of the seminiferous tubule cycle and the presence of degenerative germ cells. In addition, there was a significant decrease in the number of Leydig cells.

CONCLUSION: The present work suggests the deleterious effects of alcohol on the testes. These effects may be due to the effect of alcohol on the gonadotrophic cells of the pituitary gland and/or directly on the seminiferous tubules and Leydig cells....

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Journal Article 2001; 22(2): 87-92 PubMed PMID: 11335884 Citation  Keywords:  Animals, Brain Ischemia:chemically induced, Capillaries:ultrastructure, Cell Communication, Cell Movement, Cerebral Cortex:blood supply, Endothelium, Vascular:ultrastructure, Extracellular Matrix:ultrastructure, Intercellular Junctions:ultrastructure, Mal.   

OBJECTIVES: Focal ischemia in the cerebral cortex has an effect on neurohypophysis. The morphological changes of microvessels of neurohypophysis were evaluated in a model of the cerebral infarction initiated by a photochemical reaction in the cerebral cortex. After photochemically induced platelet aggregation, we observed the morphological features of angiogenesis.

METHOD: The model of photochemically-induced cerebral ischemia was used. Seven days after intravenous injection of rose bengal and irradiation from a halogen lamp source through an intact cranium, the sampled material from neurohypophysis is processed for transmission electron microscopy using standard procedures.

RESULTS: We observed morphological features of the new vessel formation: the alterations in the endothelium and extracellular matrix during separation of the endothelial cell from each other in a "mother" vessel, the migration of the endothelial cells in the extracellular matrix, the communication of the lumen of the new and the "mother" vessels.

CONCLUSION: We observed development of the angiogenic phenotype in the neurohypophysis after focal ischemia in the cerebral cortex. The endothelium, basement membrane and extracellular matrix undergo morphological alterations which lead to new blood vessel formation....

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Journal Article 2001; 22(2): 81-86 PubMed PMID: 11335883 Citation  Keywords:  Animals, Basement Membrane:pathology, Blood Platelets:pathology, Brain Ischemia:chemically induced, Capillaries:ultrastructure, Cerebral Cortex:blood supply, Endothelium, Vascular:ultrastructure, Erythrocytes:pathology, Extracellular Matrix:ultrastructure.   

OBJECTIVES: In our investigations we have reported that photochemical reaction leading to brain ischemia can also be precipitated with visible light from a non-coherent light source. It was revealed that focal cerebral ischemia after photochemical reaction cause the alterations in the capillaries ultrastructure and perivascular spaces of the barrier-competent regions of the brain. The purpose of this study is to first characterize the ultrastructural morphological consequences of photochemically induced ischemia in the cerebral cortex on the capillaries of neurohypophysis as the barrier-free region of the brain.

METHOD: We used a model of ischemic brain damage due to obliteration of microvessels following the photochemical reaction. Rats were treated with an intravenous injection of rose bengal and irradiated from a halogen lamp source through an intact cranium to precipitate microvascular damage. Material for electron microscopic studies were sampled from the neurohypophysis 1 and 4 days after irradiation (4 animals in each group) in experimental group and 1 and 4 days after a rose bengal injection in control group.

RESULTS: Investigations in transmission electron microscopy revealed platelet aggregation on the endothelium preceded by its early ultrastructural damage. In the capillaries of the neurohypophysis, one and four days after irradiation, numerous microthrombi adhering to the damaged endothelium were present. The capillary vessels contained a continuous, rather than a fenestrated endothelium. The basement membrane was thickened, blurred and locally multiplicated.

CONCLUSION: Our results show that experimentally-induced thrombosis of cortical microvessels leads to alterations in the capillaries of neurohypophysis....

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Journal Article 2001; 22(1): 53-73 PubMed PMID: 11393163 Citation  Keywords:  Adrenal Glands:physiology, Animals, Biological Clocks, Blood Pressure:physiology, Chronobiology Disorders:physiopathology, Chronobiology Phenomena, Chronotherapy, Circadian Rhythm:physiology, Drug Administration Schedule, Genomics, Homeostasis, Humans, Pi.   

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Case Reports 2001; 22(1): 49-52 PubMed PMID: 11335880 Citation  Keywords:  Autoantibodies:analysis, Female, HLA-DR5 Antigen:genetics, Hepatitis C, Chronic:complications, Histocompatibility Testing, Humans, Interferon-alpha:adverse effects, Middle Aged, Thyroiditis, Autoimmune:genetics,.   

OBJECTIVES: The authors described a case of Hashimoto's disease during interferon-alpha (IFN-alpha) treatment for chronic viral C hepatitis in a patient with the specific genetic susceptibility associated with the thyroid disease.

RESULTS: A 60-year-old woman with chronic active viral C hepatitis (HCV genotype = 3a) started IFN-alpha therapy in November '96. Before treatment thyroid function tests were normal and anti-thyroid (anti-thyroglobulin and anti-thyroid peroxidase) Abs were negative. During IFN therapy, serum aminotransferases fell within the normal range and viremia (serum HCV-RNA) became negative after one year. After 20 months, the patient presented clinical features of primary hypothyroidism. Anti-thyroid Abs were found positive. Hormonal, ultrasonographic, radioiodine scanning and fine needle aspiration findings were consistent with the diagnosis of Hashimoto's thyroiditis. The tissutal typing of the patient showed the presence of Human Leukocyte Antigen (HLA) DRB1*11 gene (corresponding to DR5 antigen). IFN-alpha therapy was suspended and a treatment with l-T4 started. Chronic viral infection relapsed after the suspension of the IFN-alpha therapy.

CONCLUSIONS: This case report showed that the clinical appearance of Hashimoto's disease after IFN-alpha therapy for chronic C hepatitis in our patient was associated with a specific genetic predisposition (DR5) for this pathology. Further studies are necessary to evaluate whether the study of HLA antigens may be a very useful tool to detect the patients with a predisposition to develop autoimmune thyroiditis, in order to make a early diagnosis of thyroid disorders during the IFN-alpha treatment....

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Clinical Trial 2001; 22(1): 45-47 PubMed PMID: 11335879 Citation  Keywords:  Adult, Aged, Bone Neoplasms:secondary, Carcinoma:blood, Carcinoma, Hepatocellular:blood, Carcinoma, Non-Small-Cell Lung:blood, Carcinoma, Renal Cell:blood, Colorectal Neoplasms:blood, Disease Progression, Endothelial Growth Factors:blood, Female, Humans, .   

OBJECTIVES: The anticancer activity of the indole melatonin has been explained to be due to its immunomodulatory, anti-prolferative and anti-oxidant effects, whereas at present no data are available about its possible influence on the angiogenesis, which has been shown to be one of the main biological mechanisms responsible for tumor dissemination. Vascular endothelial growth factor (VEGF) is the most active angiogenic factor, and the evidence of abnormally high blood levels or VEGF has been proven to be associated with poor prognosis in cancer patients. To investigate the influence of melatonin on angiogenesis, in this preliminary study we have evaluated the effects of melatonin therapy on VEGF blood levels in advanced cancer patients.

MATERIAL & METHODS: The study included 20 metastatic patients, who progressed on previous conventional antitumor therapies and for whom no other effective treatment was available. Melatonin was given orally at 20 mg/day in the evening for at least 2 months. Serum levels of VEGF were measured by an enzyme immunoassay on venous blood samples collected at 15-day intervals.

RESULTS: The clinical response consisted of minor response (MR) in 2, stable disease (SD) in 6 and progressive disease (PD) in the remaining 12 patients. VEGF mean levels decreased on therapy, without, however, statistical differences with respect to the pre-treatment values. In contrast, by evaluating changes in VEGF levels in relation to the clinical response, non-progressing patients (MR + SD) showed a significant decline in VEGF mean concentrations, whereas no effect was achieved in progressing patients.

CONCLUSIONS: This study, by showing that melatonin-induced control or the neoplastic growth is associated with a decline in VEGF secretion, would suggest that the pineal hormone may control tumor growth at least in part by acting as a natural anti-angiogenic molecule, with a following opposition or angiogenesis-dependent cancer proliferation....

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Journal Article 2001; 22(1): 39-44 PubMed PMID: 11335878 Citation  Keywords:  Adult, Aged, Antiviral Agents:adverse effects, Comorbidity, Female, Follow-Up Studies, Hepatitis C, Chronic:drug therapy, Humans, Incidence, Interferon-alpha:adverse effects, Male, Middle Aged, Prevalence, Retrospective Studies, Risk Factors, Sex Distribu.   

OBJECTIVES: To clarify the relationship between interferon-alpha (IFN-alpha) therapy and autoimmune thyroiditis in chronic hepatitis C virus (HCV) infection, we investigated a selected number of patients without basal thyroid dysfunctions.

MATERIALS AND METHODS: 130 patients (average age: 20-70), with chronic HCV infection and without basal clinical and laboratory signs of autoimmune thyroiditis were divided into two groups: IFN-alpha treated (A) and untreated (B) patients. Group A received IFN-alpha (three million U.I./3 times a week) for six months; group B was followed for the same period. Thyroid peroxidase and thyroglobulin autoantibodies were measured by radioimmunoassay; thyroid function was measured by radioimmunoassay (free thyroxine and triiodothyronine) and immunoradiometric assay (thyroid stimulating hormone).

RESULTS: After a 6-month period, thyroid autoantibodies positivity was documented in 21.1% of group A and in 10.3% of group B patients, both statistically relevant (p<0.001 and p<0.011, respectively). The comparison between the two groups was not statistically relevant (p=0.142).

CONCLUSIONS: Our study showed a prevalence of de novo thyroid autoimmunity in chronic HCV patients treated with IFN-alpha, confirming previous data in literature. The lack of a significant difference between treated and untreated patients strongly suggests that the anti-thyroid autoimmune response is linked to the HCV infection itself. Moreover, IFN-alpha therapy probably does not represent a risk factor in renewing the autoimmune processes of the thyroid gland. Thyroid function and autoantibodies must be systematically monitored in patients with HCV infection, especially in female and IFN-alpha treated population, not only to verify the possible thyroid abnormalities but also to rule out concomitant autoimmune diseases....

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