[Malignant lymphoma of the testis: report of two cases]

Two cases on non-Hodgkin's malignant lymphoma (NHL) of the testis are reported. A 63-year-old man with left painless scrotal swelling underwent orchiectomy. Although prophylactic irradiation was performed under the diagnosis of seminoma, subsequent immunohistochemistry revealed NHL, large diffuse cell type (B type). He had stage IEA disease. Chemotherapy with cyclophosphamide, adriamycin vincristine and prednisolone was performed. The second case was in a 63-year old man with right painless scrotal swelling. Orchiectomy revealed NHL, diffuse medium cell type (B type). Because of tumor in the retrosternum, he had stage IIIEA disease. Chemotherapy and irradiation to the contralateral testis was performed.

[Descending necrotizing mediastinitis secondary to retropharyngeal abscess--a case report]

A 69-year-old man complained of a sore throat, neck swelling, and disturbance of swallowing with dyspnea. He underwent tracheostomy and cervical drainage. The plain chest roentgenogram and CT scans suggested mediastinitis, so he was transferred to our hospital. Cultures revealed a mixed aerobic and anaerobic infection. On hospital day 2, the neck was explored and pus was found in the connective tissue. Despite drainage and intravenous panipenem with betamipron and clindamycin, he remained febrile and a mediastinal abscess was seen on repeat CT. On hospital day 10, reexploration of the mediastinum was done through cervical and right thoracotomy incisions. A large amount of pus was drained from the posterior mediastinum and its necrotic tissue was debrided. Myocardial infarction occurred intraoperatively, but the patient was successfully resuscitated. Following this procedure, the patient's condition and radiologic findings gradually improved. Cultures of the drain fluid became negative, and he was discharged on hospital day 103. In conclusion, both transcervical drainage and aggressive mediastinal exploration via thoracotomy are essential to salvage a patient with descending necrotizing mediastinitis. CT scanning is useful for early diagnosis of mediastinitis and for follow up.

Positive correlation between prolonged potentiation of binding of double-stranded oligonucleotide probe for the transcription factor AP1 and resistance to transient forebrain ischemia in gerbil hippocampus

Gel retardation electrophoresis revealed that binding of a radiolabelled double-stranded oligonucleotide probe for the nuclear transcription factor activator protein-1 was markedly potentiated in the CA1 and CA3 subfields and the dentate gyrus of the hippocampus of the gerbils with transient forebrain ischemia for 5 min, which is known to induce delayed death of pyramidal neurons exclusively in the CA1 subfield. The potentiation was transient in the vulnerable CA1 subfield, but persistent up to 18 h in the resistant CA3 subfield and dentate gyrus. However, no significant alteration was detected in endogenous levels of cyclic AMP response element binding protein phosphorylated at serine133 in these three different hippocampal structures 3 h after the reperfusion. On the other hand, hypothermia during ischemia which is known to protect the CA1 subfield against ischemic damages, led to a prolonged elevation of the activator protein-1 binding up to 9 h after the reperfusion in this vulnerable subfield at least in part through expression of c-Fos protein. Moreover, activator protein-1 binding was significantly elevated in the CA1 subfield up to 12 h after forebrain ischemia for 2 min which is shown not to induce marked damages to the vulnerable subfield. These results suggest that prolonged elevation of DNA binding activity of activator protein-1 may be responsible for molecular mechanisms underlying the unique vulnerability and/or resistance of particular subfields to a transient ischemic insult in the gerbil hippocampus.

Liquid-crystal microlens with a beam-steering function

A novel beam-steering device that makes use of a nematic liquid crystal (LC) is proposed and demonstrated. The beam-steering function is attained with a LC microlens with a divided hole-patterned electrode structure (DE-LC microlens). Optical properties of the DE-LC microlens are investigated and three-dimensional variable-focusing and beam-steering properties are verified experimentally for the first time, to our knowledge.

[A case of far-advanced gastric cancer treated with neoadjuvant combination chemotherapy of UFT, low-dose CDDP and leucovorin, followed by subtotal gastrectomy with curative intent]

We herein present a case of a 70-year-old man with the tentative diagnosis of far-advanced gastric cancer supposed to be beyond surgical intervention. Neoadjuvant chemotherapy enabled us to perform subtotal gastrectomy with curative intent. The man was admitted to our hospital with the chief complaint of poor appetite. Because preoperative examinations revealed a mass adjacent to the portal vein and common bile duct, which was suspected to be lymphnode metastasis or gastric cancer directly invading those vital structures, 4 weeks of neoadjuvant combination chemotherapy (NACC) (CDDP 10 mg/body, day 1 through day 5/week, UFT 600 mg/body, every day, Leucovorin 15 mg/body, every day) was given with resultant curative resection of the tumor one month after completion of NACC.

Cytotoxic T-lymphocytes recognizing P-glycoprotein in murine multidrug-resistant leukemias

A multidrug-resistant murine lymphoid leukemia P388/ADR overexpresses P-glycoprotein (P-gp), an active transporter that pumps cytotoxic drugs out of cells and a product of mdr1 gene. Cytotoxic T lymphocytes (CTL) that showed cytotoxicity against P388/ADR were generated from mixed lymphocyte tumor cell culture. CTL do not kill drugsensitive parental P388 (P388/parent) that does not express P-gp. Monoclonal antibody against P-gp inhibited cytotoxic activity. Similar results were obtained in another multidrug-resistant cell line P388/VP-16. Cytotoxic activity was mediated by Thy1+ CD4- CD8+ T-cells. When P388/ADR was treated with murine IL-4, expression of P-gp was downregulated. Monoclonal antibody against interleukin-4 (IL-4) abrogated the IL-4-induced suppression of P-gp. Cytolytic activity of CTL against IL-4-treated P388/ADR was dose dependently inhibited. These results suggest that P-gp is immunogenic and can be a target of CTL in this murine leukemia model.

Purification of a vascular apoptosis-inducing factor from hemorrhagic snake venom

Hemorrhagic snake venom induces apoptosis in vascular endothelial cells specifically. We report here the purification of an apoptosis-inducing factor from the venom of the rattlesnake Crotalus atrox. The purified factor was a homodimeric protein with a molecular mass of 110 kD and an isoelectric point of 8.5. When exposed to the factor, vascular endothelial cells in culture died, with the characteristic features of apoptosis, such as fragmentation of cells and cleavage of DNA into fragments that yielded a characteristic ladder pattern upon electrophoresis. The activity seemed to be specific to endothelial cells. This factor may prove to be a useful tool for studies of the molecular mechanisms of vascular apoptosis.

A novel high-performance liquid chromatographic assay for vitamin D metabolites using a coulometric electrochemical detector

A new, highly sensitive HPLC assay method using an electrochemical detector (ECD) for multiple assay of vitamin D metabolites is reported. The assay involves extracting lipids from plasma with methylene chloride and methanol, purification on Zorbax SIL column with 5.5% (v/v) iso-propanol in hexane and quantification by HPLC-ECD. A coulometric system, composed of the dual electrode analytical cell and a guard cell, was used for ECD of the eluting compounds. The potentials applied to detectors 1 and 2 in a dual electrode analytical cell were adjusted to +0.20 V and +0.60 V, respectively. This method is sensitive to 20 pg of 25-hydroxyvitamin D3 [25(OH)D3] and of 24R,25-dihydroxyvitamin D3 [24,25(OH)2D3]. Calibration curves gave linearity from 20-1000 pg for 25(OH)D3 and 24,25(OH)2D3. The detection limit was approximately 50 pg ml-1 for 25(OH)D3 and 24,25(OH)2D3 in plasma. This sensitivity combined with an overall recovery of 25(OH)D3 (81.5 +/- 2.6%, mean +/- S.E.) allows the measurement of trace amount of 25(OH)D3 with only 20 microliters of plasma. Intra- and interassay RSD values were 5.3 and 9.7% for 25(OH)D3 and 6.3 and 9.7% for 24,25(OH)2D3, respectively. Plasma levels of 25(OH)D3 and 24,25(OH)2D3 in normal adults were 15.9 +/- 2.8 ng ml-1 (n = 10) and 1.4 +/- 0.5 ng ml-1 (n = 10), respectively. This method allows the determination of 25(OH)D2 and 25(OH)D3 for evaluating their nutritional and clinical status. From these results, it is concluded that the proposed HPLC-ECD assay system is useful for the determination of vitamin D metabolites in biological fluids as a highly sensitive physicochemical method.

mRNA distribution and membrane localization of the OAT-K1 organic anion transporter in rat renal tubules

OAT-K1, a renal organic anion transporter, which mediates methotrexate uptake, was analyzed for mRNA distribution along microdissected nephron segments and the immunolocalization in isolated plasma membranes from rat kidney. By using a reverse transcription-coupled PCR, OAT-K1 mRNA was detected predominantly in the superficial and juxtamedullary proximal straight tubules. Western blotting with antiserum for OAT-K1 revealed that the transporter protein with the apparent molecular mass of 40 kDa was expressed exclusively in the brush-border membranes from rat kidney. These findings suggest that the OAT-K1 is localized in the brush-border membranes of the renal proximal straight tubules.

Augmented inhibitory effect of superoxide dismutase on superoxide anion release from macrophages by direct cationization

Superoxide dismutase (SOD) was modified into cationized form (Cat-SOD) in order to enhance its pharmacological efficacy based on an electrostatic interaction. The inhibitory effect of Cat-SOD on superoxide anion release from inflammatory macrophages and its cellular interaction were studied in vitro. Cat-SOD exhibited an excellent inhibitory effect on superoxide anion release from the macrophages, and this effect surpassed those of native SOD and SOD modified with mannose (Man-SOD) which is taken up via mannose receptor-mediated endocytosis by macrophages. In the presence of colchicine, a microtubule-disruptive agent, the inhibitory effect of Cat-SOD was slightly impaired, whereas the effect of Man-SOD completely disappeared. The intracellular localization of fluorescein isothiocyanate-labeled SOD, Cat-SOD and Man-SOD observed by confocal laser microscopy supported the difference in their abilities to eliminate superoxide anions. The different sensitivities of Cat-SOD and Man-SOD to colchicine were also confirmed by the confocal laser microscopic images, suggesting their distinct intracellular trafficking pathways in the macrophages. In conclusion, Cat-SOD is desirable for its pharmacological activity, which is probably the result of its ability to be delivered to the vicinity of NADPH-oxidase which locates in the cell membrane and generates superoxide anions.

Simplified method for the determination of 25-hydroxy and 1alpha,25-dihydroxy metabolites of vitamins D2 and D3 in human plasma. Application to nutritional studies

A simplified method for the determination of 25-hydroxy and 1alpha,25-dihydroxy metabolites of vitamins D2 and D3 in human plasma was developed. Plasma samples were deproteinizated and applied to a Bond Elut C18OH cartridge to separate 25-hydroxyvitamin D (25-OH-D) and 1alpha,25-dihydroxyvitamin D [1,25(OH)2D] fractions. The 25-OH-D fraction was purified by a Bond Elut C18 cartridge and 25-OH-D2 and 25-OH-D3 were assayed by HPLC using a Zorbax SIL column. The 1,25(OH)2D fraction obtained above was subsequently applied to HPLC using a Zorbax SIL column to separate 1,25(OH)2D2 and 1,25(OH)2D3 fractions which were determined by a radioreceptor assay (RRA) using calf thymus receptor. The method was applied to nutritional studies.

Secretory production of erythropoietin and the extracellular domain of the erythropoietin receptor by Bacillus brevis: affinity purification and characterization

Bacillus brevis secretes a large amount of cell wall proteins into the culture medium. For construction of Bacillus brevis expression-secretion vectors of human erythropoietin (EPO) and the extracellular domain of mouse erythropoietin receptor (sEPOR), cDNA for each mature form was inserted into a plasmid containing the promoter region and the signal-peptide encoding region of a cell wall protein. Culture supernatants of transformants were affinity purified using a monoclonal antibody-fixed gel for EPO and and EPO-fixed gel for sEPOR. The affinity purification efficiently removed unwanted proteins, giving samples with sufficiently high purity to analyze amino acid sequences of N-terminal regions and biological activities. Combination of this secretory production and affinity purification may facilitate isolation of a large amount of pure EPO and sEPOR, and is useful for further understanding the molecular mechanism of interaction between EPO and EPOR.

Effects of low polymer content in a liquid-crystal microlens

A small number of bifunctional monomers are mixed with a nematic liquid crystal (LC) and cured with a distributed electric field, which is produced by a circular-hole-patterned electrode structure. A gradient type of lens, that is, a LC microlens, is investigated for various polymer concentrations. Addition of 3% polymer is enough to freeze the gradient-index properties of the structure in the form of a convex lens, and a polymer-stabilized LC microlens is demonstrated. Although a lower concentration of polymer cannot hold the distribution properties in a curing process, it can maintain the variable focus as a nematic material can. The polymer networks can also eliminate the disclination line that usually appears and causes the lens in this type of LC device to deteriorate.

The dnaK operon of Bacillus subtilis is heptacistronic

In 1992, we described the cloning and sequencing of the dnaK locus of Bacillus subtilis which, together with transcriptional studies, implied a tetracistronic structure of the operon consisting of the genes hrcA, grpE, dnaK, and dnaJ. We have repeated the Northern blot analysis, this time using riboprobes instead of oligonucleotides, and have detected a heat-inducible 8-kb transcript, suggesting the existence of additional heat shock genes downstream of dnaJ. Cloning and sequencing of that region revealed the existence of three novel heat shock genes named orf35, orf28, and orf50, extending the tetra- into a heptacistronic operon. This is now the largest dnaK operon to be described to date. The three new genes are transcribed as a part of the entire dnaK operon (8.0-kb heptacistronic heat-inducible transcript) and as part of a suboperon starting at an internal vegetative promoter immediately upstream of dnaJ (4.3-kb tetracistronic non-heat-inducible transcript). In addition, the Northern blot analysis detected several processing products of these two primary transcripts. To demonstrate the existence of the internal promoter, a DNA fragment containing this putative promoter structure was inserted upstream of a promoterless bgaB gene, resulting in the synthesis of beta-galactosidase. Challenging this transcriptional fusion with various stress factors did not result in the activation of this promoter. To assign a biological function to the three novel genes, they have each been inactivated by the insertion of a cat cassette. All of the mutants were viable, and furthermore, these genes are (i) not essential for growth at high temperatures, (ii) not involved in the regulation of the heat shock response, and (iii) sporulation proficient. Blocking transcription of the suboperon from the upstream heat-inducible promoter did not impair growth and viability at high temperatures.

Nationwide survey of bone grafting performed from 1980 through 1989 in Japan

Nationwide surveys were conducted in 1985 and 1989 on the status of bone grafting performed in Japan. At the first survey, questionnaires were sent to 527 hospitals, with 218 responding. Of 26,800 bone grafts performed, 96.4% were autografts, and the remaining 3.6% were allografts and xenografts. Most allografts were bone chip grafts (85%), followed by massive bone grafts excluding osteoarticular grafts (14%). Osteoarticular allografts and whole bone allografts composed only 0.4% and 0.5% of the total, respectively. At the second survey, questionnaires were sent to 2053 hospitals, with 967 responding. The use of synthetic bone substitutes and bone grafts was investigated in the second survey. Of 87,994 bone grafts performed, 94.3% were autografts, 3.2% were synthetic bone substitutes, 1.9% were banked bone allografts, 0.4% were fresh allografts, and 0.2% were xenografts. Most of all grafts were bone chip grafts (57.1%), followed by massive bone grafts excluding osteoarticular grafts (40.3%). Osteoarticular grafts and whole bone grafts accounted for only 0.3% and 2.3% of the totals, respectively. Although the number of patients requiring bone grafts increased yearly, bone allografts were not widely used in Japan.

Absence of atherosclerosis evolution in the coronary arterial segment covered by myocardial tissue in cholesterol-fed rabbits

The evolution of atherosclerotic lesions is suppressed in the intima of the human coronary artery, beneath myocardial bridges. To elucidate the mechanism of the protective effect, we investigated morphological changes using the rabbit coronary artery as a model. Rabbit fed a 1%-cholesterol diet were killed at intervals up to 20 weeks. Two short segments of the left coronary arteries running in the epicardial adipose tissue (EpiLAD) and subsequently running in the myocardium (MyoLAD) were compared morphologically. The intima of the EpiLAD had flat endothelial cells with a polygonal shape, and demonstrated raised atherosclerotic lesions with increase in serum cholesterol level. In contrast, the intima of the MyoLAD was free of atherosclerotic lesions throughout the study, and the endothelial cells were spindle-shaped and engorged. While ferritin particles reached only the surroundings of the internal elastic lamina in the MyoLAD, they permeated into the media of the EpiLAD. We suggest that myocardial bridges suppress coronary atherosclerosis by an alteration of endothelial permeability, which may be due to changes in haemodynamic force tending towards a higher shear stress. The data provide an insight into the relationship between haemodynamics and the development of coronary atherosclerosis.

Insulin-like growth factors and insulin stimulate erythropoietin production in primary cultured astrocytes

Erythropoietin (EPO) is established as a major regulator of erythropoiesis. However, we and others have shown that neurons express erythropoietin receptor (EPO-R), that astrocytes produce EPO and that EPO may act as a neurotrophic factor in the CNS. We also found that EPO production is activated by insulin and insulin-like growth factors (IGFs) in astrocytes in a dose-dependent manner and that IGF-I was the most potent activator. The concentrations required for half-maximal activation were 3 nM IGF-I, 10 nM IGF-II and 100 nM insulin. The oxygen concentration regulates EPO production; hypoxia stimulates EPO production in astrocytes. The stimulatory effect of IGFs and insulin on EPO production in astrocytes was not affected by the oxygen concentration of astrocyte culture. Insulin and IGFs did not increase the total protein synthesis of astrocytes but increased EPO mRNA levels, indicating that EPO production is stimulated at the mRNA level. It appeared that the growth factor-induced accumulation of EPO mRNA in astrocytes was caused by activation of the tyrosine kinase-signal transduction pathway, because tyrosine phosphorylation of receptors for IGF-I and insulin was activated when astrocytes were stimulated by these growth factors.

Erythropoietin receptor is expressed in rat hippocampal and cerebral cortical neurons, and erythropoietin prevents in vitro glutamate-induced neuronal death

Recently, erythropoietin has been shown to be produced by astrocytes and its production is hypoxia-inducible. In the present study, we demonstrated, using a reverse transcription-polymerase chain reaction assay and immunostaining of the cells, that the erythropoietin receptor was expressed in cultured hippocampal and cerebral cortical neurons of day 19 rat embryo. Erythropoietin protected the cultured neurons from glutamate neurotoxicity. Neurons cultured for seven to 10 days were exposed to glutamate for 15 min and after culture for a further 24 h in the absence of glutamate the neuron survival was assayed. Significant protection was observed with erythropoietin from 3 pM (c. 100 pg/ml) in a dose-dependent manner. The protection was completely reversed by co-application of a soluble erythropoietin receptor, an extracellular domain capable of binding with erythropoietin. For exhibition of the neuroprotective effect, exposure of neurons to erythropoietin approximately 8 h prior to exposure to glutamate was required. Experiments with the inhibitors indicated that RNA and protein syntheses were necessary for the protection. However, exposure to erythropoietin for a short period (5 min or less) was sufficient to elicit the protective effect. The protective effect of erythropoietin was blocked by the simultaneous addition of EGTA. These findings and the previous finding that erythropoietin induces a rapid and transient increase in intracellular Ca2+ concentration in neuronal cells suggest that erythropoietin plays a neuroprotective role in brain injury caused by hypoxia or ischemia and that erythropoietin-induced Ca2+ influx from outside of the cells is a critical initial event yielding an enhanced resistance of the neurons to glutamate toxicity.

In vitro neurotoxicity of amyloid β-peptide cross-linked by transglutaminase

Transglutaminase catalyzes the intermolecular cross-linking of peptides between Gln and Lys residues, forming an ε-(γ-glutamyl) lysine bond. Amyloid β-peptide, a major constituent of the deposits in Alzheimer disease, contains Lys16, Lys28, and Gln15 which may act as substrates of transglutaminase. Transglutaminase treatment of amyloid β-peptide (1-28) and amyloid β-peptide (1-40) yielded cross-linked oligomers. Transglutaminase-treated Aβ retarded neurite extension of PC12 cells, and rat cultured neurons of hippocampus and septum, brain areas severely affected by Alzheimer disease, and subsequently caused cell death, whereas the transglutaminase-untreated counterparts did not show harmful effects. The transglutaminase-catalyzed oligomers of amyloid β-peptide and their neurotoxicity may be involved in two characteristics in Alzheimer disease, neuronal degeneration and formation of the insoluble deposits.

ABBREVIATIONS

AD - Alzheimer disease, Aβ - amyloid β-peptide, DMEM - Dulbecco's modified Eagle's medium, DMEM/F-12-1:1 mixture of DMEM and Ham's F-12 medium, FCS - fetal calf serum, HS - horse serum, PAGE - polyacrylamide gel electrophoresis, MTT - 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, NGF - nerve growth factor, TGase - transglutaminase.

[Pulmonary cavernous hemangioma--identification of its endothelial cell origin by immunohistological staining]

A 45-year-old woman was referred to our hospital because of a tumorous shadow in the S10 segment of the left lung. A chest computed tomography (CT) scan showed a nodular lesion with a slightly irregular margin and no contrast enhancement. CT-guided aspiration biopsy was tried but did not result in a histological diagnosis. The tumor was excised during video-assisted thoracoscopic surgery. Histological examination of the specimen revealed cavernous hemangioma. Most cells lining the lumen of the cavernous structure stained positively for von Willebrand factor antibody and negatively for anti-epithelial membrane antigen antibody, which suggests that the tumor was associated with endothelium. To the best of our knowledge, this is the first report of a case in which the diagnosis of pulmonary cavernous hemangioma was confirmed with an immunohistological study.