Inhibition of P-selectin attenuates neutrophil-mediated myocardial dysfunction in isolated rat heart

The expression of P-selectin on postischemic endothelium after reperfusion has been shown to trigger neutrophil attachment and the subsequent inflammatory responses. Extensive studies have demonstrated that P-selectin is involved in the progression of neutrophil-mediated myocardial infarction and no-reflow phenomenon. In the present study, we examined the effects of selectin inhibitors, sialyl Lewis X-oligosaccharide and anti-P-selectin monoclonal antibody, PB1.3 on neutrophil-dependent left ventricular dysfunction in isolated rat heart. The hearts were subjected to global ischemia for 20 min and then reperfused for 45 min with rat plasma in the presence of human neutrophils during the first 5 min of the reperfusion. Left ventricular developed pressure and other parameters of the left ventricular function deteriorated throughout the reperfusion period in a neutrophil-dependent manner. In contrast, the coronary flow was reduced early on (< 15 min) but recovered to the level in the hearts reperfused with no neutrophils 45 min after the reperfusion. We examined the effects of selectin inhibitors under experimental conditions in which the hearts were perfused with 30 million neutrophils. The treatment with sialyl Lewis X-oligosaccharide at a dose of 0.3 mg/min resulted in amelioration of left ventricular developed pressure to 57.2 +/- 14%, compared to 26.1 +/- 4.3% in the saline-treated group (P < 0.05). Similarly, the treatment with mouse anti-human P-selectin monoclonal antibody (IgG1) PB1.3 at a dose of 0.6 mg/min resulted in the prominent recovery of left ventricular developed pressure after 45 min of reperfusion (59.9 +/- 9.3% vs. 26.1 +/- 4.3% in the saline-treated group, P < 0.05). PB1.3 also attenuated the elevation of left ventricular end-diastolic pressure compared to that of the saline-treated group during the reperfusion period. Moreover, the treatment with PB1.3 ameliorated the recovery of coronary flow until 10 min after the reperfusion and the recovery of coronary flow 10 min after the reperfusion was 55.2 +/- 9.2%, as compared to 28.2 +/- 7.7% in saline-treated hearts (P < 0.05). To our knowledge, this is the first direct demonstration that the specific inhibition of P-selectin results in the inhibition of neutrophil-mediated left ventricular dysfunction or myocardial stunning.     

Immunolocalization of prolyl 4-hydroxylase in fibroblasts cultured from Tenon's capsule of humans

Background: The excessive accumulation of extracellular matrix (ECM) with the repopulation of fibroblasts may lead to an unsuccessful outcome of glaucoma filtering surgery. We examined the immunolocalization of ECM components and prolyl 4-hydroxylase, an enzyme involved in collagen biosynthesis, in cultured Tenon's capsule fibroblasts (TCFs) of humans to evaluate the production of ECM in the cells. Methods: We used light microscopy to evaluate the immunolocalization of prolyl 4-hydroxylase and ECM components, collagen types I, III, and IV, cellular fibronectin, and laminin in TCFs. Ultrastructural localization of the enzyme was also evaluated by electron microscopy. Results: Immunoreactivity with monoclonal antibodies against the and subunits of the enzyme or with the polyclonal antibody against it was detected in the cytoplasm of the cells in a fine granular pattern, indicating its localization in the indoplasmic reticulum (ER). Immunoreactivity for the enzyme was detected in the cisternae of the ER on electron microscopy. Types I and III collagen reactivities were also observed in the cytoplasm in a fine granular pattern. T reactivity was present diffusely on the cell surface. The distribution of laminin reactivity in the cytoplasm resembled that of types I and III collagen. Cellular fibronectin reactivity was observed in the ECM in a reticular pattern. Conclusion: Prolyl 4-hydroxylase was located in the cisternae of the ER. TCFs produced a variety of ECM components in vitro. The results provide insight into the fibrotic process during scar formation at the site of a bleb following filtering surgery.     

Electron microscopical and immunohistochemical studies on the induction of "Qi" employing needling manipulation.

During a sparrow-pecking and twisting-needle manipulation to the acupoints BL 23, 24 and 25 for an induction of "Qi", it was found that some transparent materials were binding to the needles after removed from the volunteer's skin. Electron-microscopical analysis of the transparent materials revealed that they corresponded to the injured fascia made up of collagen fibers, elastic fibers, fibroblasts, adipocytes and mast cells. Rarely were nerve fiber-like structures observed in the materials. Immunohistochemically, calcitonin gene-related peptide-positive nerve fibers could be demonstrated in the acupoint BL 24 associated fascia. A possible functional relationship between the needle manipulation and the induction of Qi-sensation is discussed along with the acupoint tissue constitution.     

Direct clipping of a large basilar trunk aneurysm via the posterior petrosal (extended retrolabyrinthine presigmoid) approach--case report

A 53-year-old female presented with an unruptured, large basilar trunk aneurysm manifesting only as headache with no neurological deficits, including absence of cranial nerve dysfunction. Cerebral angiography disclosed a large aneurysm with a wide neck arising from the midbasilar artery. We treated the aneurysm surgically via the posterior petrosal approach. Five angled clips were applied sequentially to the aneurysm and the basilar artery was successfully reconstructed. Electrophysiological monitoring was continued during the operation and showed no changes. Following the operation, the patient suffered from transient right abducens nerve palsy, which persisted for 3 months. Postoperative angiography showed that the aneurysm was obliterated, and the patency of the basilar artery was preserved.     

Loss of regulation of circulating 1,25-dihydroxyvitamin D with paradoxically decreased serum phosphate levels in individuals with recurrent kidney stones

A low serum phosphate concentration is characteristic in individuals in whom kidney stones form, this being related to serum 1,25-dihydroxyvitamin D, parathyroid hormone and urinary phosphate excretion. In order to determine whether these parameters are related to recurrence of stone formation, they were analyzed in single and recurrent stone formers as well as controls. An inverse correlation between serum levels of phosphate and 1,25-dihydroxyvitamin D was observed in control subjects, indicating that a drop in serum phosphate results in upregulated circulating 1,25-dihydroxyvitamin D level in controls. While the circulating low phosphate level upregulated the 1,25-dihydroxyvitamin D level in single stone formers, the elevation was less than expected from the drop in serum phosphate in recurrent stone formers. The results thus suggest that loss of upregulation of 1,25-dihydroxyvitamin D by serum levels of phosphate might be important for stone formation. The possibility of deregulation of 1,25-dihydroxyvitamin D to maintain physiological requirements in stone formers and prevent further nephrolithiasis therefore warrants attention. Received: 27 January 1999 / Accepted: 25 June 1999     

Treatment of acute promyelocytic leukemia: strategy toward further increase of cure rate.

Acute promyelocytic leukemia (APL) has become a curable disease by all-trans retinoic acid (ATRA)-based induction therapy followed by two or three courses of consolidation chemotherapy. Currently around 90% of newly diagnosed patients with APL achieve complete remission (CR) and over 70% of patients are curable. To further increase the CR and cure rates, detection and diagnosis of this disease at its early stage is very important, hopefully before the appearance of APL-associated coagulopathy. In induction therapy, concomitant chemotherapy is indispensable, except for patients with low initial leukocyte counts. Prophylactic use of intrathecal methotrexate and cytarabine should be done, particularly for patients with hyperleukocytosis. If patients relapse hematologically or even molecularly, arsenic trioxide will be the treatment of choice under careful electrocardiogram monitoring. Am80, liposomal ATRA, gemtuzumab ozogamicin or ATRA in combination with cytotoxic drugs may be used at this stage or later. Allogeneic SCT will be the treatment of choice after patients of age <50 years have relapsed, provided that they have HLA-identical family donors or DNA-identical unrelated donors.     

Possible dominant-negative mutation of the SHIP gene in acute myeloid leukemia.

The SH2 domain-containing inositol 5'-phosphatase (SHIP) is crucial in hematopoietic development. To evaluate the possible tumor suppressor role of the SHIP gene in myeloid leukemogenesis, we examined primary leukemia cells from 30 acute myeloid leukemia (AML) patients, together with eight myeloid leukemia cell lines. A somatic mutation at codon 684, replacing Val with Glu, was detected in one patient, lying within the signature motif 2, which is the phosphatase active site. The results of an in vitro inositol 5'-phosphatase assay revealed that the mutation reduced catalytic activity of SHIP. Leukemia cells with the mutation showed enhanced Akt phosphorylation following IL-3 stimulation. K562 cells transfected with the mutated SHIP-V684E cDNA showed a growth advantage even at lower serum concentrations and resistance to apoptosis induced by serum deprivation and exposure to etoposide. These results suggest a possible role of the mutated SHIP gene in the development of acute leukemia and chemotherapy resistance through the deregulation of the phosphatidylinositol-3,4,5-triphosphate (PI(3,4,5)P3)/Akt signaling pathway. This is the first report of a mutation in the SHIP gene in any given human cancer, and indicates the need for more attention to be paid to this gene with respect to cancer pathogenesis.     

Tumor lysis syndrome in widely metastatic small-cell lung cancer

Tumor lysis syndrome is a rare complication of nonhematologic malignancies that results from massive necrosis of neoplastic cells after chemotherapy. This syndrome consists of life-threatening metabolic derangements, including severe hyperphosphatemia, hyperkalemia, hyperuricemia, and hypocalcemia, and may result in renal failure and death if not recognized early and treated appropriately. We report a case of tumor lysis syndrome after induction chemotherapy in a patient with widely metastatic smallcell lung cancer. This case emphasizes the importance of awareness and early treatment of this syndrome.     

Pharmacokinetic study of low- versus high-dose medroxyprogesterone acetate (MPA) in women

The present study was conducted to compare the pharmacokinetics (PK) of low-dose versus high-dose medroxyprogesterone (MPA) as a once-daily oral administration. Of 32 patients, all women, enrolled in this PK study, 18 received 600 mg MPA daily and 14 received 1200 mg daily. Detailed PK data were obtained on day 1 and after more than 4 weeks of MPA treatment. In addition, multiple data for the minimum steady-state concentration (Css min) were analyzed. The MPA serum concentrations were measured by high-performance liquid chromatography. Wide interpatient variability was found in the PK parameters obtained both on day 1 and after more than 4 weeks. There were no clear relationships between the oral dose and the MPA peak concentration (Cmax), area under the time versus concentration curve (AUC), or mean Css min. Weight gains of 10% or more were demonstrated more frequently in the high-dose group (P<0.01). Liver dysfunction (n=5) did not influence the PK of MPA. Five patients demonstrated extremely low AUC and Cmax (<10 ng/ml) values on day 1. Phenobarbital, dexamethasone and betamethasone were being taken concomitantly with the MPA each by one patient. The serum MPA concentrations were markedly increased after the discontinuation of phenobarbital in that patient, suggesting a drug interaction. At present we cannot recommend the high dose of MPA, except in clinical studies, from a PK or a pharmacodynamic points of view. Received: 2 May 1997 / Accepted: 13 October 1997