Formation of thick, curving bundles of actin by drebrin A expressed in fibroblasts

Drebrin A is a neuron-specific protein, the expression of which is regulated during development. Upon transfection of fibroblasts with drebrin A cDNA, the protein is expressed at high levels in fibroblasts and the outgrowth of highly branched, neurite-like cell processes is induced. In this report, we describe a biochemical examination of the binding of drebrin A to actin filaments. We also demonstrate by an immunocytochemical method that, when drebrin A is expressed in transfected cells, it binds to actin filaments and is concentrated in cell processes. Furthermore, we provide evidence that thick, curving bundles of actin together with drebrin are formed in some of the transfected cells. Our results suggest that the actin filaments that bind drebrin might be a novel class of actin filaments and might play a role in neuronal morphogenesis.

Epstein-Barr virus-associated post-transplant non-Hodgkin's lymphoma: establishment and characterization of a new cell line

A new human lymphoma cell line derived from pulmonary non-Hodgkin's lymphoma that developed in a renal transplant recipient was established from the patient's pleural effusion and designated PTLC-1. PTLC-1 grew aggressively in suspension, forming very loose clumps with a doubling time of about 18.9 h. The morphological, chromosomal, and immunophenotypic characteristics of the patient's tumor cells and PTLC-1 cells were very similar. PTLC-1 showed a monoclonal rearrangement of IgH gene and was highly tumorigenic in athymic nude mice. In situ hybridization, Southern blot hybridization and polymerase chain reaction demonstrated the presence of Epstein-Barr virus (EBV) genome in the patient's tumor and PTLC-1. PTLC-1 has been maintained in culture for over 60 months. Since EBV has been implicated in the pathogenesis of post-transplant lymphoma, this new cell line should serve as a useful experimental model for studying the etiology and biology of lymphoma developing in organ transplant recipients.

Influence of efonidipine hydrochloride, calcium antagonist on the epithelium of prostates in spontaneously hypertensive rats

The hypertensive effect on the development of the prostatic abnormality in spontaneously hypertensive rats (SHRs) was examined using Efonidipine hydrochloride, a calcium antagonist. The control SHRs were given a high sodium and potassium diet (SP-diet) alone, and the treated SHRs were given a SP-diet with 0.15% Efonidipine hydrochloride from 8 to 28 weeks of age. The systolic blood pressure (SBP) in the control SHRs increased with age, while the elevation of SBP was significantly prevented in the treated SHRs. Light-microscopically, the prostatic lesion was observed both in the control and treated SHRs. The glandular lumen was narrowed with papillary protrusions, and the epithelium was composed of tall columnar epithelial cells. However, hypertension-induced complications in kidneys and hearts were not observed in the treated SHRs. These results suggested that the prostatic abnormality of SHRs might not be the consequent lesions upon hypertension.

Effect of surface roughness of hydroxyapatite-coated titanium on the bone-implant interface shear strength

We have investigated the bone-implant interface shear strength of hydroxyapatite (HA)-coated Ti-6Al-4V (HA-coating A) (roughness average, Ra = 3.4 +/- 0.5 microns) and HA-coated Ti-6Al-4V with a rougher surface (HA-coating B) (Ra = 8.4 +/- 1.8 microns). There was no significant difference between HA-coating A and HA-coating B implants with respect to the bone-implant interface shear strength as determined in push-out tests using the transcortical model in adult dogs. The bone-implant interface shear strength of bead-coated porous Ti-6Al-4V was significantly greater than that of both HA-coating A and HA-coating B implants. The failure site, as determined by scanning electron microscopy, was the coating-substrate interface, not the coating-bone interface. This indicates a need to protect the HA coating from the direct shear forces. HA coating enhances early bone growth into the porous surface of the implant. Long-term fixation should depend on bone anchoring to this porous surface. Hydroxyapatite coatings must be developed which do not obstruct the pores of the surface of the implant.

Treatment of severe myoclonic epilepsy in infants with bromide and its borderline variant

We studied the efficacy of bromides (BR) as add-on therapy in 11 patients with severe myoclonic epilepsy in infants (SME) and in another 11 with the borderline variant of SME (BVSME). Study subjects were aged 8.5-183 months (mean 64.4 months). Longest duration of BR treatment was 37 months (range 4-37 months; mean 19.7 months). Eight of 22 (36%) of patients with generalized tonic-clonic seizures (GTCS) had an excellent effect (> 75% reduction in total seizure frequency or duration) and 9 (41%) had a moderate effect (50-75% reduction) 3 months after introduction of BR. Twelve months after initiation of BR. 5 of the patients with significant improvement were no longer responsive; ultimately, therefore, 6 had an excellent effect and 2 had a moderate effect. Of those with partial seizures (n = 5) and myoclonic/absence seizures (n = 5), only 1 patient in each group showed a moderate effect at the 12-month time-point. Dosages and serum concentrations of BR ranged from 30 to 100 mg/kg (mean 58 mg/kg) and from 64 to 159 mg/dl (mean 101 mg/dl), respectively. Of the 12 patients experiencing side effects, including drowsiness, appetite loss, and skin rash, 1 required a reduction in BR dosage because of an extensive acneiform rash on the face. The results show that BR treatment holds promise for patients with SME and BVSME and should therefore be investigated further.

Cine-magnetic resonance imaging of cor triatriatum

Two adult patients with cor triatriatum, which was shown by echocardiography and magnetic resonance imaging (MRI) using both spin-echo and cine-MR techniques, are presented. Spin-echo MRI clearly demonstrated an anatomical relationship between the membrane and pulmonary veins or left atrial appendage, which was not clear on transthoracic echocardiography. In addition, cine-MRI depicted abnormal flow through the fenestration of the anomalous membrane (case 1 and 2) and shunted flow through the associated atrial septal defect (case 2).

Multiple factors contribute to acetylcholine-induced renal afferent arteriolar vasodilation during myogenic and norepinephrine- and KCl-induced vasoconstriction. Studies in the isolated perfused hydronephrotic kidney

Acetylcholine (ACh) elicits vasodilation by releasing a number of endothelium-derived relaxing factors (EDRFs). We used the isolated perfused hydronephrotic rat kidney to examine the characteristics of ACh-induced vasodilation of renal afferent arterioles during different types of underlying vasoconstriction. Basal arteriolar tone was increased by either elevating perfusion pressure to 180 mm Hg (myogenic), administering 0.3 mumol/L norepinephrine (NE), or elevating medium potassium concentration to 30 mmol/L (KCl). ACh (10 mumol/L) completely reversed myogenic and NE-induced vasoconstriction and reversed KCl-induced vasoconstriction by 80 +/- 5%. However, whereas ACh produced a sustained vasodilation during KCl- and NE-induced vasoconstriction, only a transient reversal of myogenic vasoconstriction was observed, and myogenic tone recovered within 5 to 10 minutes. ACh-induced vasodilation of arterioles preconstricted with KCl was markedly inhibited by either indomethacin (100 mumol/L) or nitro-L-arginine (100 mumol/L) and was completely abolished by pretreatment with both inhibitors. In contrast, indomethacin and nitro-L-arginine had no effect on the transient response to ACh observed during pressure-induced vasoconstriction. In vessels preconstricted with NE, nitro-L-arginine converted the normally sustained response to ACh to a transient vasodilation, which was refractory to both nitric oxide synthase and cyclooxygenase inhibition. Since this component was not observed during KCl-induced vasoconstriction, it may reflect the actions of an, as yet unidentified, endothelium-derived hyperpolarizing factor (EDHF). Our findings thus suggest that prostanoids, nitric oxide, and EDHF all contribute to ACh-induced renal afferent arteriolar vasodilation and that the relative contributions of these individual EDRFs depends on the nature of the underlying renal vascular tone.

Changes in beta-carotene levels by long-term administration of natural beta-carotene derived from Dunaliella bardawil in humans

Long-term administration of a beta-carotene preparation derived from Dunaliella bardawil, a beta-carotene-rich algae, was studied in healthy young male volunteers. The daily administration of 60 mg of the beta-carotene preparation (30 mg of all-trans beta-carotene and 30 mg of 9-cis beta-carotene) was performed and beta-carotene concentrations were determined in the plasma, red blood cells (RBC), platelets (PLT), and mononuclear cells (MN). The all-trans beta-carotene level increased four-, two-, and threefold the baseline in plasma, PLT, and MN, respectively. Basal levels of 9-cis beta-carotene in plasma, PLT, and MN were low and found as one-tenth, one-fifth, and one-fifth of all-trans beta-carotene, which increased three-, two-, and 1.5-fold the baseline, respectively. Plasma and RBC alpha-tocopherol levels were not changed by the intake of beta-carotene. No side effects or toxicities were documented in any of the subjects during the administration period. In conclusion, the bioavailability of beta-carotene derived from Dunaliella bardawil was preferential for all-trans beta-carotene, although a small amount of the 9-cis form was detected in the plasma and blood cells.

Mutations of the adenomatous polyposis coli gene in the mutation cluster region: comparison of human pancreatic and colorectal cancers

We analyzed the adenomatous polyposis coli (APC) tumor-suppressor gene as one of the possible genes mutated in human pancreatic carcinomas. DNAs from 39 surgical specimens were subjected to single-strand conformation polymorphism analysis of polymerase chain reaction products and the mutation cluster region (MCR) of the gene was examined. We also examined the same region of DNAs from 27 surgical specimens of sporadic colon carcinomas and detected mutations in 11 carcinomas (41%). This mutation frequency in colon carcinomas was similar to those reported previously. Using this system, we detected a mutated APC gene in one of 39 pancreatic carcinomas. The results indicated that mutation of the MCR in the APC gene is involved in genesis of some of human pancreatic carcinomas, but its frequency is much lower than in colorectal carcinomas.

Primary osteosarcoma of the cerebrum with immunohistochemical and ultrastructural studies: report of a case

A 57-year-old woman with primary intracerebral osteosarcoma is reported. The tumor was identified by computed tomography as a mass with hemorrhage in the right parietal lobe. The surgical and pathological examinations confirmed an osteosarcoma of intracerebral origin. She suffered from repeated local recurrence of the tumor and died about 1 year after the onset. The pathological findings showed features of osteoblastic osteosarcoma with numerous osteoclast-like multinucleated giant cells. Immunohistochemically, tumor cells were positive for vimentin, and partially for actin. Multinucleated giant cells were reactive with vimentin and CD68 antibodies. Ultrastructurally, tumor cells were rich with rough endoplasmic reticulum. These findings are consistent with the histological features of skeletal or extraskeletal osteosarcoma. This is the third case of primary intracerebral osteosarcoma reported in the literature and the first one analyzed ultrastructurally.

Immunization coverage and infant mortality rate in developing countries

We examined whether immunization coverage (IMC) is one of the predictors of infant mortality rate (IMR), as a single indicator representing the availability of primary health care (PHC) services in developing countries. Multiple regression analysis showed that partial correlation coefficients for IMR with immunization coverage (-0.224), logarithm of per capita GNP (-0.294), total fertility rate (0.269), and adult literacy rate (-0.325) were all statistically significant (p < 0.001) in 97 developing countries which make up more than 97% of the population in all the developing countries of the world. Multiple correlation coefficients of IMR with these four variables in 97 countries was 0.921. Thus, more than 80% of variation of IMR in developing countries were explained by the variation of the four variables. The study also showed that IMC was well correlated (simple correlation) with the four indicators of the availability of primary health care services; access to local care (0.730), care of pregnant women (0.603), delivery care (0.666), and infant care (0.553), all of which were statistically significant (p < 0.001) in the 48 developing countries which make up 42% of the population of all developing countries. Multiple correlation coefficients of these four variables was 0.787. About 60% of the variation of IMC will be explained by the variation of the four variables. Thus we conclude that immunization coverage is one of the main predictors of the infant mortality rate. It represents one of the health intervention components which can be used as a proxy indicator of the availability of PHC service in developing countries.

Renin inhibitor: relationship between molecular structure and oral absorption

Common problems in developing renin inhibitors are low solubility, insufficient oral absorption, and fast hepatic clearance. We focused on the molecular structure of renin inhibitors to overcome these problems. Cyclodextrins (CD) improved the low solubility of renin inhibitors, with beta-CD showing the best ability to dissolve renin inhibitors. The intestinal absorption of renin inhibitors varied with both their solubility and molecular structure. Coadministration of beta-CD improved the intestinal absorption of some renin inhibitors with low solubility as measured by transport into the mesenteric vein in the absorption experiment using the rat intestinal loop. Substitutions at both the N and C terminals was essential for absorption from the small intestine. A naphthyl group at the N-terminal further improved intestinal absorption. A carrier system appeared to be involved in the intestinal absorption of some renin inhibitors. N-methylation at the amide bond of thiazolylalanine suppressed the high hepatic clearance of one of the test compounds 18 which was well absorbed from the small intestine and it improved its oral bioavailability.

[Problems and present status of clinical trials for esophageal carcinoma]

This paper reviews clinical trials for esophageal carcinoma, mainly from the results of the JEOG (Japanese Esophageal Oncology Group) study. Preoperative radiotherapy was not conducive to survival of esophageal cancer patients. On the third JEOG trial, postoperative chemotherapy of CDDP+VDS was equivalent to survival as 50Gy of postoperative irradiation. And on the further fourth trial, survival was also equivalent between the two groups treated with surgery alone or postoperative chemotherapy of CDDP+VDS. This fact reveals the in effectiveness of these therapies. The response rate from JEOG phase II study of CDDP and 5-FU was 35.9%, and RCT of surgery alone versus surgery + postoperative chemotherapy with CDDP+5-FU was ongoing as the fifth JEOG trial. Chemo-radiotherapy seemed to be very effective for esophageal cancer patients, and it may provide a complete cure for them in the future.

Comparison of sedative effects induced by medetomidine, medetomidine-midazolam and medetomidine-butorphanol in dogs

Sedative effects of combinations of medetomidine at 20 micrograms/kg--midazolam at 0.3 mg/kg (Me-Mi) and medetomidine at 20 micrograms/kg--butorphanol at 0.1 mg/kg (Me-B) were evaluated comparing with those of medetomidine alone (20, 40 and 80 mu/kg). All dogs given Me-Mi or Me-B were smoothly and rapidly induced to more profound and longer sedation than those by medetomidine alone. Especially, Me-Mi produced desirable sedation with moderate reflex depression, analgesia, excellent muscle relaxation and immobilization without further side effects. This potent effect of this combination seemed to be induced by a synergistic interaction between medetomidine and midazolam. This combination is available and valuable as a chemical restraint agent in dogs for various diagnostic or therapeutic procedures accompanied by light pain.

Effect of long-term administration of beta-carotene on lymphocyte subsets in humans

To examine whether or not beta-carotene alters immune indexes, we performed a single-blind trial in healthy male nonsmokers. Lymphocyte subsets were assessed by double labeling with monoclonal antibodies before and after 44 wk of administration of either beta-carotene (60 mg/d; n = 10) or placebo (n = 10). In addition, we measured the beta-carotene concentrations in plasma, mononuclear cells (MNC), platelets, and red blood cells (RBCs), as well as the plasma alpha-tocopherol concentration. An increase of plasma and MNC beta-carotene concentrations to four and three times the baseline value was noted after 2 and 4 wk, respectively. The CD4-CD8 ratio increased after 9 mo of beta-carotene administration whereas natural killer cells, virgin T cells, memory T cells, and cytotoxic T cells remained unaltered throughout the study. No side effects or toxicities were detected by a questionnaire survey and routine laboratory tests.

Nisamycin, a new manumycin group antibiotic from Streptomyces sp. K106. II. Structure determination and structure-activity relationships

Nisamycin, a novel manumycin group antibiotic, was isolated from the culture broth of Streptomyces sp. K106. Structural elucidation of nisamycin was achieved by detailed NMR spectral analyses and comparison of the NMR data of nisamycin with those of other manumycin group antibiotics. The structure was confirmed by chromic acid oxidation. The absolute stereochemistry of nisamycin was determined to be 4R, 5S and 6R from the CD spectra of nisamycin and chromic oxidation of nisamycin. In addition, some structure activity-relationships were examined.

Antagonistic effects of antipamezole on medetomidine-midazolam induced sedation in dogs

Antagonistic effect of atipamezole (80 micrograms/kg) on medetomidine (20 micrograms/kg)-midazolam (0.3 mg/kg) induced sedation was evaluated in dogs. Atipamezole effectively reversed sedation and significantly shortened arousal time and total recovery time without apparent side effects. Atipamezole also effectively reversed changes in heart rate, respiratory rate and body temperature produced by medetomidine-midazolam. The possible use of atipamezole as a reversal agent might enhance the value and availability of medetomidine-midazolam for a chemical restraint agent in dogs.

Nisamycin, a new manumycin group antibiotic from Streptomyces sp. K106. I. Taxonomy, fermentation, isolation, physico-chemical and biological properties

Nisamycin, a new manumycin group antibiotic, was isolated from the culture broth of Streptomyces sp. K106. This strain was designated to genus Streptomyces by the taxonomic features. Nisamycin was purified by ethyl acetate extraction, silica gel column chromatography, preparative silica gel TLC, and Sephadex LH-20 column chromatography as a pale yellow powder. Nisamycin is active against Gram-positive bacteria and fungi, and exhibits a cytotoxic activity.

[Ocular murine cytomegalovirus infection in immunocompromised hosts]

Cytomegalovirus (CMV) chorioretinitis is one of the commonest complications in immunocompromised hosts. However, the entire scope of ocular involvement during generalized CMV infection in immunocompromised hosts is yet to be elucidated. Balb/c nude mice were inoculated intraperitoneally with Smith strain of salivary gland passaged murine cytomegalovirus. Eight days after infection, they were sacrificed and the pathological features of virus spread were studied by immunofluorescence method. Subconjunctival tissues, corneal stroma, outer ocular muscles and occasional choroidal tissue are the site of positive fluorescence in the eye. At the same time, viral antigens were detected in the various organs such as spleen, liver, salivary glands, etc. Balb/c nude mice were injected intraperitoneally with silica three days and one day prior to virus infection to suppress their macrophages. The localization of viral antigens in the silica-treated mice was similar to that in untreated mice. When the peripheral blood obtained from the nude mice infected for 8 days was titrated for the virus, cell-free virus and blood-cell-associated virus was detected. These results indicated that cell-free virus is the major source of its spread.

Specific detection of positive and negative stranded hepatitis C viral RNA using chemical RNA modification

Since hepatitis C virus (HCV), a major causative agent of posttransfusional non-A, non-B hepatitis, is a positive stranded RNA virus, it is supposed to replicate via a negative RNA strand. Although strand specific reverse transcription-polymerase chain reaction (RT-PCR) method was recently developed to detect each strand of HCV RNA, the specificity of the strategy has remained to be determined. In this study, using in vitro transcribed positive and negative stranded HCV RNAs mixed with hepatic cellular RNA from normal liver, we found that this strategy did not distinguish between the two RNA strands, but that chemical modification of RNA samples at the 3' end followed by strand specific RT-PCR made specific detection possible. Liver tissues, sera and peripheral blood mononuclear cells (PBMC) from ten patients with chronic HCV infection were analyzed with the novel strategy of RT-PCR combined with RNA modification. Positive and negative strands of HCV RNA were detected in liver tissues of ten (100%) and nine (90%) cases, respectively. Negative RNA strand was detected also in sera of five cases (50%), positive strand being detected in nine cases (90%). In PBMC, positive strand of HCV RNA was detected in eight cases (80%), whereas negative strand in only one case (10%), suggesting that HCV has much less cellular tropism to PBMC than to hepatocytes.

Comparative study of CA242 and CA19-9 for the diagnosis of pancreatic cancer

A comparative study of a new tumour marker, CA242, and CA19-9 was conducted with special reference to their diagnostic usefulness in pancreatic cancer. CA242 showed sensitivity similar to that of CA19-9 for overall cases and early cases (stage I tumour) of pancreatic cancer. For other malignancies, the positive rates of CA242 were lower than those of CA19-9 except for colorectal cancer. An important characteristics of CA242 was that it was only slightly and infrequently elevated in the sera of patients with benign diseases such as chronic pancreatitis, chronic hepatitis and liver cirrhosis. This characteristic was more apparent in the patients with benign obstructive jaundice, indicating that the serum level of this marker was scarcely affected by cholestasis. Using cut-off levels corresponding to a 90% specificity, the clinical results obtained with CA242 in the diagnosis of pancreatic cancer were similar to those obtained with CA19-9, except that CA19-9 was falsely negative in some patients with early-stage pancreatic cancer. These findings suggest the usefulness of this marker for screening pancreatic cancer in patients on their first hospital visit. However, CA242 was found to be influenced by the Lewis blood group system. This unfavourable result is attributed to the C241 catcher antibody of this assay system, which has almost the same epitope specificity as the C50 and the NS19-9 monoclonal antibodies. In conclusion, CA242 is superior to CA19-9 in diagnosing pancreatic cancer by virtue of its higher specificity.