The repetitive activation of extracellular signal-regulated kinase is required for renal regeneration in rat

In this study, we investigated the activation of p42 extracellular signal-regulated kinase (ERK2) during renal regeneration after HgCl2-induced acute renal failure (ARF) in rat. ERK2 activation was observed at 5 and 29 hr after HgCl2 injection, respectively. The tyrosine phosphorylation of hepatocyte growth factor receptor (c-MET) occurred between 2.5 and 5 hr after the treatment. On the other hand, the phosphorylation of epidermal growth factor receptor (EGFR) was transiently observed at 29 hr after the injection. The peak of ornithine decarboxylase activity as a marker of G1 phase was at 10 hr, and subsequently the labeling index of proliferating cell nuclear antigen as a marker of S phase increased at 53 hr. These results indicate that the repetitive activation of ERK2 related to the phosphorylation of c-MET and EGFR is required for the renal regeneration in HgCl2-induced ARF of rat.

[A case of osteolytic metastases from breast cancer effectively treated with pamidronate]

A 55-year-old woman complained of neck pain ten years after the mastectomy. She was diagnosed as multiple bone metastases and received chemoendocrine therapy with 5'-DFUR and tamoxifen. Bone scintigram showed progressive disease, so we attempted biweekly administration of fadrozole and pamidronate (30 mg). After four months, pamidronate administration relieved her neck pain. CT revealed that all lytic lesions of cervical and thoracic vertebra showed sclerosis 11 months after pamidronate infusion. New lytic lesions are not defined, and the sclerosis has continued thus far. Pamidronate therapy is promising as an effective treatment in patients with osteolytic metastasis from breast cancer.

Differential effect of exogenous human chorionic gonadotrophin on progesterone production from normal or malfunctioning corpus luteum

To examine whether luteal phase defect is, in part, causally related to insufficient gonadotrophin stimulation, we compared the relation of the increment of serum progesterone concentrations in response to human chorionic gonadotrophin (HCG) with its basal level at mid-luteal phase. Thirty-eight naturally cycling infertile women aged between 27-41 years old were evaluated for hormonal responses to HCG injection at the mid-luteal phase. We measured luteinizing hormone (LH), follicle stimulating hormone (FSH), oestradiol and progesterone concentrations, before and 1, 2 and 3 h after the administration of HCG (5000 IU, i.m.) 7 days after ovulation verified by ultrasonography. Eleven out of 38 women exhibited progesterone concentrations below 10 ng/ml (low progesterone group), and those remaining showed progesterone concentrations of > or = 10 ng/ml (normal progesterone group). The basal LH, FSH and oestradiol concentrations were essentially the same in both groups. Progesterone concentrations rose significantly 1 h after the injection and levelled off thereafter. The increment of progesterone concentrations at 1 h in the normal progesterone group was 5.7 ng/ml on the average, whereas that in low progesterone group was 1.1 ng/ml. Furthermore, the percentage increase in progesterone concentrations at 1 h in the normal progesterone group was significantly greater than that in the low progesterone group. Both groups equally exhibited significant but marginal increases in oestradiol concentrations 1 h after the injection. LH and FSH concentrations at 3 h decreased significantly in both groups. In summary, HCG readily stimulates progesterone production in normally functioning corpus luteum whereas its stimulatory effect is minimal on malfunctioning corpus luteum. This suggests that luteal phase defect is not caused by inadequate gonadotrophin stimulation and, therefore, does not benefit from HCG administration.

Structure-function studies of iron-sulfur clusters and semiquinones in the NADH-Q oxidoreductase segment of the respiratory chain

Our recent experimental data on iron-sulfur clusters and semiquinones in the complex I segment of the respiratory chain is presented, focusing on the Paracoccus (P.) denitrificans and bovine heart studies. The iron-sulfur cluster N2 has attracted the attention of investigators in the research field of complex I, since the mid-point redox potential of this cluster is the highest among all clusters in complex I, and is pH dependent (60 mV/pH). It is known that this cluster is located either in the NQO6 (NuoB in E. coli/PSST in bovine heart nomenclature) or in the NQO9 (NuoI/TYKY) subunit in the amphipathic domain of complex I. Our preliminary data indicate that the cluster N2 is located in the NuoB rather than the long-advocated NuoI subunit, and may have a unique ligand structure. We previously reported spin-spin interactions between cluster N2 and two distinct species of semiquinone (designated SQNf and SQNs) associated with complex I. A parallel intensity change was observed between the SQNf (g = 2.00) signal and the N2 split g parallel signal, further supporting our proposed interaction between SQNf and N2 spins.

HLA class I and class II expression of pulmonary adenocarcinoma cells and the influence of interferon gamma

BACKGROUND

The clinico-biological significance of HLA (both class I antigen and class II one) expressed on tumor cells still remains controversial.

METHODS

Tumor cells were freshly separated from 33 surgical specimens of pulmonary adenocarcinoma. The tumor cells were incubated for 24 h in the presence or absence of IFN-gamma (130 International Units/ml). After incubation, the cells were cytocentrifuged onto glass slides and immunostained with either an anti-HLA class I (A, B, C) monoclonal antibody or anti-HLA class II (DR) one.

RESULTS

In 22 of 33 cases (66.7%), the HLA class I were individually expressed by more than 60% of tumor cells while so were the HLA class II in 15 (45.4%). No significant correlation was observed between the HLA class I expression and the HLA class II one. The proportion of HLA class I-positive tumor cells correlated with neither the grade of histological differentiation nor the stage of disease. In contrast, the proportion of HLA class II-positive tumor cells correlated with both the grade of histological differentiation and the stage. In most cases, IFN-gamma was found to increase the proportion of class II-positive tumor cells as well as that of class I-positive cells.

CONCLUSIONS

The above findings thus suggested that the HLA class II expression might therefore represent a manifestation of cellular differentiation and that IFN-gamma may, as a result, have the potential to differentiate cancer cells.

[Clinical analysis of patients with severe pneumonia requiring mechanical ventilation]

To clarify the clinical features and select the appropriate antibiotic therapy for patients with severe pneumonia requiring mechanical ventilation, we performed a clinical analysis of 65 patients with this condition. The following results were obtained. The majority of the patients were elderly males, whose performance status was poor (PS 2.2) and who had an underying disease. Abnormal physical signs included tachypnea, tachycardia and consciousness disturbance. Abnormal laboratory findings included hypoalbuminemia, and liver and renal dysfunction. The causative microorganisms were isolated from half of these patients. A number of antibiotics were administered and steroid pulse therapy was also performed for half of these patients. Nevertheless the prognosis was poor because the percentage of deaths was high (50.8%).

[Altered electrocardiogram during general anesthesia in a patient with intermittent Wolff-Parkinson-White conduction]

A delta wave, which had not been detected in the preoperative electrocardiogram (ECG), was observed just before induction of anesthesia in a 53-year-old male scheduled for partial pancreatectomy. His ECG, diagnosed as intermittent Wolff-Parkinson-White (WPW) conduction, varied markedly displaying different wide QRS complexes with a short PR interval, and then returned abruptly to normal during anesthesia. WPW syndrome belongs to the category of pre-excitation syndromes, which is characterized by the accelerated abnormal conduction to the ventricle and paroxysmal tachyarrhythmias caused by an accessory pathway. We should consider the influence of anesthesia-related agents on atrioventricular conduction, and aim at preventing and managing tachyarrhythmias caused by this syndrome.

Localization-dependent translation requires a functional interaction between the 5' and 3' ends of oskar mRNA

The precise restriction of proteins to specific domains within a cell plays an important role in early development and differentiation. An efficient way to localize and concentrate proteins is by localization of mRNA in a translationally repressed state, followed by activation of translation when the mRNA reaches its destination. A central issue is how localized mRNAs are derepressed. In this study we demonstrate that, when oskar mRNA reaches the posterior pole of the Drosophila oocyte, its translation is derepressed by an active process that requires a specific element in the 5' region of the mRNA. We demonstrate that this novel type of element is a translational derepressor element, whose functional interaction with the previously identified repressor region in the oskar 3' UTR is required for activation of oskar mRNA translation at the posterior pole. The derepressor element only functions at the posterior pole, suggesting that a locally restricted interaction between trans-acting factors and the derepressor element may be the link between mRNA localization and translational activation. We also show specific interaction of two proteins with the oskar mRNA 5' region; one of these also recognizes the 3' repressor element. We discuss the possible involvement of these factors as well as known genes in the process of localization-dependent translation.

Intramolecular masking of nuclear import signal on NF-AT4 by casein kinase I and MEKK1

T cell activation requires the import of NF-AT transcription factors to the nucleus, a process promoted by calcineurin-dependent dephosphorylation and inhibited by poorly understood protein kinases. Here, we report the identification of two protein kinases that oppose NF-AT4 nuclear import. Casein kinase Ialpha directly binds and phosphorylates NF-AT4, resulting in the inhibiton of NF-AT4 nuclear translocation. MEKK1 indirectly suppresses NF-AT4 nuclear import by stabilizing the interaction between NF-AT4 and CKIalpha. CKIalpha thus acts to establish an intramolecular masking of the nuclear location signal on NF-AT4, while MEKK1 augments this mechanism, and may further provide a link to signal transduction pathways regulating NF-AT4.

Directed evolution of an aspartate aminotransferase with new substrate specificities

The substrate specificity of aspartate aminotransferase was successfully modified by directed molecular evolution using a combination of DNA shuffling and selection in an auxotrophic Escherichia coli strain. After five rounds of selection, one of the evolved mutants showed a 10(5)-fold increase in the catalytic efficiency (kcat/Km) for beta-branched amino and 2-oxo acids and a 30-fold decrease in that for the native substrates compared with the wild-type enzyme. The mutant had 13 amino acid substitutions, 6 of which contributed 80-90% to the total effect. Five of these six substitutions were conserved among the five mutants that showed the highest activity for beta-branched substrates. Interestingly, only one of the six functionally important residues is located within a distance of direct interaction with the substrate, supporting the idea that rational design of the substrate specificity of an enzyme is very difficult. The present results show that directed molecular evolution is a powerful technique for enzyme redesign if an adequate selection system is applied.

Cytotoxin produced by Escherichia coli isolated from chickens with swollen head syndrome (SHS)

This study was conducted to determine the presence of selected virulence factors in Escherichia coli recovered from swollen head syndrome (SHS) in chickens. Thirty-six (72%) of 50 isolates of E. coli from SHS were shown to produce a cytotoxin that was active on Vero and HeLa but not on Y-1 cells. The toxin was called VT2y because the cytotoxic effect on Vero cells was morphologically similar to that produced by E. coli verotoxins (VTs), and this effect was neutralized by antiserum against VT2 but not by antiserum against VT1. Interestingly, DNA probes for VT1 and VT2 failed to hybridize the VT2y-positive isolates with total DNA. Although the role of this toxin in SHS has yet to be demonstrated, the marked edema which characterizes affected chickens is consistent with the action of a toxin such as verotoxin which targets vascular endothelium.

[A case of Listeria monocytogenes sepsis in an elderly who survived]

A 81-year-old man who complained of fever and disturbance of consciousness was admitted to our hospital. Listeria monocytogenes type 1/2aA was cultured from only the blood. He was treated with gamma-globrine and sensitive antibiotics (PAPM/BP, EM) immediately after admission, and recovered in spite of multiple organ failure due to septic shock. He was not an immunocompromised host and did not have complication of meningitis, but had rhabdomyolysis and liver dysfunction.

A putative tumor suppressor, TSG101, acts as a transcriptional suppressor through its coiled-coil domain

TSG101 is thought as a putative tumor suppressor gene, and mutations of this gene were recently found in 7 of 15 breast cancer patients, though the physiological function remains to be elucidated. In this report, we showed that TSG101 protein acts as a transcriptional suppressor for estrogen receptor (ER) as well as other members of the nuclear hormone receptor super-family, VP16, and on its own. The basal promoter activity was also inhibited by TSG101. The suppression of transcription by TSG101 protein required its coiled-coil domain, which is also shown to be required for the tumor suppressive function. Expressed TSG101 protein did not have any histone acetylase nor deacetylase activity, which certain transcriptional co-factors have. The requirement of the same domain in the TSG101 protein for transcriptional suppression and in the tumor suppression indicates a possibility that transcriptional suppression of TSG101 is related to its tumor suppression.

The inhibitory effect of vitamin E on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung tumorigenesis in mice based on the regulation of polyamine metabolism

The present study was carried out in order to estimate a usefulness of vitamin E against 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in mice. Feeding high doses of vitamin E suppressed the NNK-induced elevation of the activity of ornithine decarboxylase, a key enzyme of polyamine biosynthesis, in the lungs of mice at 4 weeks after injection. In contrast, the vitamin elevated the NNK-induced decrease of the activity of spermidine/spermine N1-acetyltransferase, a key enzyme of polyamine biodegradation. In conjugation with these events, the NNK-increased level of proliferating nuclear cell antigen as a marker of cell proliferation was suppressed by vitamin E treatment. Also, the supply of high doses of vitamin E suppressed NNK-induced lung tumorigenesis in mice. These results suggest that vitamin E inhibits the development of lung tumors in mice treated with NNK, partly due to the regulation of polyamine metabolism.

Identification and characterization of the ARP1 gene, a target for the human acute leukemia ALL1 gene

ALL1, the human homologue of Drosophila trithorax, is directly involved in human acute leukemias associated with abnormalities at 11q23. Using the differential display method, we isolated a gene that is down-regulated in All1 double-knockout mouse embryonic stem (ES) cells. The gene, designated ARP1 (also termed RIEG, Ptx2, or Otlx2), is a member of a family of homeotic genes containing a short motif shared with several homeobox genes. Using a bacterially synthesized All1 polypeptide encompassing the AT-hook motifs, we identified a 0.5-kb ARP1 DNA fragment that preferentially bound to the polypeptide. Within this DNA, a region of approximately 100 bp was protected by the polypeptide from digestion with ExoIII and DNase I. Whole-mount in situ hybridization to early mouse embryos of 9.5-10.5 days indicated a complex pattern of Arp1 expression spatially overlapping with the expression of All1. Although the ARP1 gene is expressed strongly in bone marrow cells, no transcripts were detected in six leukemia cell lines with 11q23 translocations. These results suggest that ARP1 is up-regulated by the All1 protein, possibly through direct interaction with an upstream DNA sequence of the former. The results are also consistent with the suggestion that ALL1 chimeric proteins resulting from 11q23 abnormalities act in a dominant negative fashion.

Direct percutaneous transluminal angioplasty for acute middle cerebral artery occlusion

PURPOSE

We review our initial experience with direct percutaneous transluminal angioplasty (PTA) as a reperfusion treatment for acute occlusion of the middle cerebral artery.

METHODS

Ten patients in whom successful thrombolysis might not be expected because of the risk of hemorrhagic complications or reocclusion were treated with direct PTA. When early ischemic findings were present on the initial CT scans and/or when lenticulostriate arteries were involved, we performed direct PTA rather than thrombolytic therapy. Direct PTA was also performed when superselective local angiography via a Tracker catheter advanced just distal to the occlusion site showed the presence of a large embolus or high-grade stenosis suggestive of thrombosis. Angioplasty was performed with a Stealth balloon catheter with a maximum diameter of 2.0 to 2.5 mm. The balloon catheter was advanced into the site of occlusion and inflated to 2 atm initially, and subsequently up to 3 atm. Two to six inflations, each of 30 seconds' duration, were performed.

RESULTS

Although the rate of initial recanalization was 100% (10 of 10), reocclusion occurred in two patients with atherothrombotic M2 occlusion. The final angiographic success rate of direct PTA was 80% (8 of 10). There were no hemorrhagic or technical complications, and five of 10 patients showed marked clinical improvement. In two of seven patients with cardioembolic M1 trunk occlusion, crushed fragments of the embolus obstructed M2 portions after direct PTA, necessitating local thrombolysis.

CONCLUSION

Direct PTA may be performed safely as an alternative to thrombolytic therapy in patients with acute occlusion of the middle cerebral artery when early CT findings and/or lenticulostriate artery involvement are present or when superselective local angiography shows the presence of a large embolus or high-grade stenosis.

[Sudden ventricular tachyarrhythmia immediately following hepatectomy in a patient with hypomagnesemia]

A 57-year-old male without pre- or intraoperative arrhythmia developed ventricular tachyarrhythmia immediately following hepatectomy. Postoperative examination of plasma electrolytes revealed severe hypomagnesemia (0.16 mmol.l-1). The arrhythmia may have been caused by hypomagnesemia and an imbalance between supply and demand of oxygen in the myocardium, due to hypovolemia and severe anemia from massive hemorrhage. We recommend that measurement of plasma magnesium concentration be included in all perioperative laboratory examinations.

Augmentation of tumor immunity in mice by intralesional injection of vitamin A

We investigated the antitumor effect of vitamin A(VA) using the double grafted tumor technique to examine whether VA administered into a primary tumor (intralesionally or i.l.) accelerates antitumor immune reactions so that growth of the secondary tumor may be more effectively inhibited than by other systemic administration routes. In the double grafted tumor system, where BALB/c mice were inoculated with MethA fibrosarcoma cells into the right inguinal region (1 x 10[6] cells) on day 0 and later into the left (3 x 10[6] cells) on day 10, the injection of VA at a dose of 1000 IU/mouse i.l., s.c., i.p., and i.v. on days 3 through 7 inhibited the growth of the secondary tumor to the same extent, while VA at the i.l. dose of 100 IU/mouse into the primary tumor inhibited more effectively than by any other administration route. VA did not inhibit the secondary MethA growth in BALB/c (nu/nu) mice. The spleen cells taken from VA-treated tumor-bearing mice prevented the growth of MethA tumors in naive BALB/c mice when given as a mixture with the MethA inoculum (the Winn assay). The delayed-type hypersensitivity (DTH) response to methylated bovine serum albumin (MBSA) antigen was augmented when VA (1000 IU) was injected at the site of the antigen injection. These results suggest that the direct interaction of VA with the tumor cells may be necessary for the tumor immunity-potentiating effect of VA, and that T-lymphocyte-mediated tumor immunity is involved in the anti-tumor effect of VA. The antitumor mechanism of VA seems to involve retinoid receptors, because the benzoic acid derivative Am80, which has been reported to exert retinoidal activity by binding to specific retinoid receptors, also showed activity.

Paragonimiasis westermani presenting as an asymptomatic nodular lesion in the lung: report of a case

A 57-year-old man with a history of having consumed fresh-water crab 8 months previously presented with a solitary mass lesion in the left lung without any symptoms. Since neoplastic disease could not be ruled out, an open biopsy was performed, and histological examination confirmed a definite diagnosis of paragonimiasis. A high level of the anti-Paragonimus westermani antibody was detected in the sera of the patient, but this level decreased substantially 3 months after chemotherapy with bithionol.

Pirarubicin might partly circumvent the P-glycoprotein-mediated drug resistance of human breast cancer tissues

BACKGROUND

Anthracyclines are the first line antitumor agents against breast cancer, and P-glycoprotein (Pgp) is thought to be the main resistance mechanism against these agents. We have evaluated the chemosensitivity of fresh surgical specimens of breast cancer and compared them with their Pgp-expression.

MATERIALS AND METHODS

The in vitro chemosensitivity of 65 surgical specimens obtained from 63 patients with advanced breast cancer was assessed by the histoculture drug response assay (HDRA) using doxorubicin (DXR), pirarubicin [(2"R)-4'-tetrahydropyranyladriamycin: THP], and epirubicin (EPIR). Breast cancer tissues were plated onto collagen gel matrix and incubated with 15 micrograms of DXR or EPIR, or 17 micrograms of THP per ml for 7 days with MTT assessed at the endpoint. The efficacy of the agents was evaluated by the inhibition index (I.I.) of the optical density detected by ELISA reader.

RESULTS

When 60% or more I.I. was regarded as in vitro sensitive at each cut-off concentration of the drugs, the overall efficacy rates were 60.7%, 48.6%, and 78.6% for DXR, EPIR, and THP, respectively. Fifty-one surgical specimens were evaluated for the immunohistochemical analysis of Pgp and the correlation between the sensitivity to anthracyclines and the expression of Pgp was compared. Pgp was expressed in 23.5% (12/51) specimens and the efficacy of anthracyclines was reduced in Pgp-positive breast cancer tissues, although this reduction was low in THP with a statistically significant difference when comparing with DXR and EPIR.

CONCLUSION

The present results suggest that THP might partly circumvent the mdr1/PgP-mediated drug resistance mechanism in human breast cancer tissue and would have some different antitumor spectra on breast cancer comparing with DXR and EPIR.

Hyperthermic enhancement of tumour growth inhibition by accelerated carbon-ions in transplantable human esophageal cancer

The study examined the effects of combination of hyperthermia (42 degrees C) and 290 MeV/u carbon-ion (C-) beams or 200 kVp X-rays on tumour regrowth delay of transplantable human esophageal cancer as an in vivo model for radiotherapy of cancer. The C-beams were more effective in the tumour growth inhibition than X-rays. The relative biological effectiveness (RBE) of C-beams against X-rays was 2.00. It was observed that the interactive hyperthermic (42 degrees C, for 30 min) enhancement of tumour regrowth delay by high-linear energy transfer (LET) C-beams was similar to that of combination of low-LET X-rays with hyperthermia. The thermal enhancement ratios (TER) were 6.10 and 5.57 for X-rays and C-beams, respectively. These results suggest that hyperthermic treatment is effective in radiotherapy not only by low-LET radiation but also by high-LET radiation such as C-beams. In conclusion, the depression of the tumour growth by the combined treatment of hyperthermia (42 degrees C) and the C-beams strongly suggests the available possible application of interdisciplinary cancer therapy for refractory tumours.

Lymphoepithelial cysts of the pancreas: demonstration of lipid component using CT and MRI

We present two cases of surgically proven lymphoepithelial cyst (LEC) of the pancreas that had a lipid component visualized by CT and MRI. Identification of this component in a pancreatic cystic lesion is a key to favor the diagnosis of LEC or splenic epidermoid cyst over other cystic lesions when the lesion is noted in an elderly patient.