Methods and findings in experimental and clinical pharmacology最新文献

Chronic graft versus host disease (GVHD) is still the main cause of long-term non-neoplastic morbidity and mortality in patients receiving an allogeneic hematopoietic stem cell transplantation. Treatment consists of a combination of corticosteroids and calcineurin inhibitors. There is no standardized therapy for cases in which this treatment fails. Recent experimental studies and clinical trials in humans have yielded promising results for imatinib, an inhibitor of tyrosine kinase enzymes involved in the pathogenesis of fibrosis. This article reviews pathophysiologic aspects of scleroderma in the context of GVHD and systemic sclerosis, the experimental bases for the use of tyrosine kinase inhibitors in these diseases, and the first clinical results.

The search for an unrelated donor must be based on the HLA typing of the donor and the host. PCR techniques have facilitated high-resolution HLA typing, but they have also elicited questions about the real impact of the various disparities on the progress of the graft Thus, whereas a donor used to be accepted based on HLA-A and B Identity determined by serology and HLA-DRB1 through molecular biology techniques, now a donor is required to have a 70/70 Identity for loci HLA-A, B, C, DRB7, and DQB7. Furthermore, the real effect of the disparities in the sixth locus of the major histocompatibility complex-HLA-DPBT-is still in doubt. This study intends to conduct a literature review of the clinical impact of the various HLA disparities In transplants from unrelated donors.

Oncolytic viruses represent a new treatment modality that may help overcome some of the most important limitations of classical radio- and chemotherapy. This new technique is based on conditioned replication of the viral genome only in cells with the genetic alterations characteristic of tumor lesions. This facilitates the selective lysis of tumor masses concomitant to viral autoamplification. As a result, the pharmacodynamic parameters involved are completely different from those of antitumor drug substances. ICOVIR-5 is an oncolytic adenovirus with a good toxicity and antitumor efficacy profile following intravenous administration. However, prior clinical experience has also revealed its most important limitations for ensuring clinical efficacy. The identification of these limitations, together with the possibilities for manipulating viral genomes, now open to door to the molecular designing of candidates offering more efficient antitumor activity and constituting genuine management alternatives in application to treatment-refractory tumors.

Pegylation implies progress in filgrastim therapy. The addition of one molecule of polyethylene glycol (PEG) increases the drug's half-life by reducing renal excretion. A single dose of pegfilgrastim is equivalent to a daily administration of G-CSF for recovering from neutropenia after cancer chemotherapy. Pegfilgrastim is also useful to mobilize hematopoietic stem cells. Several studies have researched its efficacy in this context, in patients with myeloma or lymphoma. Outcomes suggest that it has an efficacy similar to daily G-CSF. In allogeneic donors, a single 12-mg dose of pegfilgrastim produces sufficient increase of CD34+ in peripheral blood, with acceptable toxicity. There is interest on the data about the various functional and biologic properties of hematopoietic stem cells mobilized with pegfilgrastim compared to G-CSF, and on the effect that these differences may have on the graft composition. The administration of a single dose of pegfilgrastim after autologous transplantation has been shown to shorten the time for leukocyte recovery in a manner similar to G-CSF

Cerebral salt wasting (CSW) frequently occurs concomitantly with subarachnoid hemorrhage (SAH). CSW induces excessive natriuresis and osmotic diuresis, reduces total blood volume, aggravates cerebral vasospasm and causes cerebral ischemia after SAH. This study examined the inhibitory effect of hydrocortisone on CSW in rat SAH models. Hydrocortisone had an inhibitory effect on CSW because hydrocortisone functioned in a dose-dependent manner to inhibit the increase in sodium excretion and sodium/potassium ratio after SAH onset. We conclude that hydrocortisone is a useful drug for the treatment of CSW after SAH.

Fungi of the genus Aspergillus are found everywhere in the natural environment; they cause invasive pulmonary aspergillosis (IPA), an infectious complication common in immunocompromised individuals, which has a mortality rate of up to 90% in patients with hematological malignancy. The first line of defense of innate immunity is the recognition of Aspergillus conidia by dendritic cells or alveolar macrophages. DC-SIGN is an integrin directly involved in this recognition; its degree of expression in immune cells and its functionality may be partly determined by genetic variations. The objective of this study was to determine whether the presence of polymorphisms of a single nucleotide in the DC-SIGN gene increases the risk of invasive pulmonary aspergillosis. For this purpose, the variants DC-SIGN-139A/G (rs2287886) and DC-SIGN+11C/G (rs7252229) were analyzed In 314 subjects (152 patients with hematologic malignancy and 162 healthy controls). Of the 152 hematologic cancer patients, 81 were diagnosed with demonstrated invasive pulmonary aspergillosis per EORTC/IFICG criteria, and the remaining 71 patients had no symptoms of the infection. An association was found between the variant DC-SIGN-139(A/G) and resistance to IPA. Carriers of the allele A (A/A + A/G) were significantly more resistant to the infection than patients with the G/G genotype (p = 0.0574). Analysis of the serum concentration of the galactomannan antigen supported the hypothesis that this polymorphism may be implicated in the susceptibility to suffer invasive pulmonary aspergillosis. Although the difference was not statistically significant, carriers of the allele G had a higher frequency of positive galactomannans than subjects with the genotype A/A (p = 0.1921). These results suggest that the variant DC-SIGN-139(A/G) in the DC-SIGN gene promoter influences the risk of invasive pulmonary aspergillosis and may therefore be used as a genetic biomarker to stratify patients according to risk.

Primary Immune thrombocytopenia or idiopathic thrombocytopenic purpura (ITP) is an acquired immune disorder presenting with abnormal hemorrhagic symptoms resulting from a decrease in the number of platelets. The disorder used to be attributed to increased destruction of platelets mediated by antibodies. In the past few years, the description of its etiopathology has changed. A deficiency in the marrow production of thrombocytes has been demonstrated; because it is associated with increased peripheral platelet destruction, the deficiency cannot be compensated. These findings have justified the realization of studies assessing the utility of second generation thrombopoietin analogues for the treatment of these patients. These drugs include romiplostim or AMG 537 (Nplate), a peptidic analogue that stimulates the thrombopoietin receptor and induces an increase In the production and differentiation of megakaryocytes. Data obtained from the clinical trials that led to the authorization and subsequent follow-up describe romiplostin as an effective and safe drug for adult patients with chronic ITR The overall response rate is 94%; despite variations in the levels of platelets throughout treatment, 50% of patients maintain the response 95% of the time, and 78% of patients discontinue or significantly reduce the use of rescue treatment. The most common adverse event is headache. Reticulin fibrosis has been described, which is reversible after treatment discontinuation.

Valeriana jatamansi (family, Valerianaceae) is a traditional medicinal herb in the Indian subcontinent. This study provides experimental evidence indicating the therapeutic effect of the extract prepared from the dried rhizome of the herb in an animal model of liver cirrhosis and on cell proliferation. Liver cirrhosis was induced in rats by thioacetamide (0.03% in drinking water for 16 weeks). After inducing liver cirrhosis, rats were administered the extract orally for 9 weeks. Treatment was found to partially reverse the elevated levels of alkaline phosphatase, γ-glutamyl transferase and selected biochemical markers of hepatic injury including drug-metabolizing enzymes. Histopathology of the hepatic tissue confirmed the therapeutic effect of the extract which corroborated with the biochemical changes. The extract is also reported to ameliorate hepatic cell proliferation in rats injected with thioacetamide. The study has implications in finding a treatment for liver cirrhosis in humans.

It has been well established that histaminergic neurons innervate densely the anterior hypothalamus and regulate several functions through the histamine H₁ receptor (H1R). However, the physiological function of the histaminergic neurons in other regions including the posterior hypothalamus has not been fully investigated. Recently, we have found a selective c-Fos expression in the caudal part of the arcuate nucleus of the hypothalamus (cARC) by food deprivation under scheduled feeding in rats. In this study, we histochemically examined the correlation of this c-Fos expression with the activation of histaminergic neurons in this region using an anti-H1R antibody. Strong H1R immunoreactivity was observed in the perikarya of the c-Fos positive cells. Abundant histamine-containing fibers were also found in the cARC and in the area between the cARC and the tuberomammillary nucleus (TM), where the histaminergic neuronal cell bodies are exclusively distributed. Our morphological observations suggest that c-Fos expression in the cARC by food deprivation under scheduled feeding is caused by the activation of histaminergic neurons projected from the TM.

Over the last decade, there has been a dramatic decline in the frequency of organ failure, infection, and severe acute CVHD as causes of non-relapse mortality after allogeneic hematopoietic cell transplantation. Gastrointestinal CVHD, however, remains a significant obstacle to survival. Patients who present with non-progressive symptoms of the upper gut phenotype of GVHD seldom progress to severe CVHD, but may have a prolonged course, they can be successfully treated with prednisone 1 mg/kg/day for a limited time, along with topical and oral glucocorticoid. Patients who present with the mid-gut phenotype of GVHD can be recognized soon after presentation by secretory protein-losing enteropathy and falling serum albumin; their treatment requires prednisone 2 mg/kg/day and probably an additional drug such as mycophenolic acid. Failure to improve identifies a cohort with a poor prognosis; secondary therapy should be started while gut mucosa is still intact, but no secondary therapies have been proven in randomized trials to improve survival. Patients whose initial presentation (large volume diarrhea, low serum albumin, jaundice, mucosal necrosis and sloughing at initial endoscopy) presages a fatal outcome have not been studied prospectively.