Isolation of a novel human canalicular multispecific organic anion transporter, cMOAT2/MRP3, and its expression in cisplatin-resistant cancer cells with decreased ATP-dependent drug transport

The human multidrug resistance protein (MRP) gene encodes a membrane protein involved in the ATP-dependent transport of hydrophobic compounds. We previously isolated a canalicular multispecific organic anion transporter, cMOAT1/MRP2, that belongs to the ATP binding cassette (ABC) superfamily, which is specifically expressed in liver, and cMOAT1/MRP2 is responsible for the defects in hyperbilirubinemia II/Dubin-Johnson syndrome. In this study, we isolated a new cDNA of the ABC superfamily designated cMOAT2/MRP3 that is homologous to human MRP1 and cMOAT1/MRP2: cMOAT2/MRP3 is 56% identical to MRP1 and 45% identical to cMOAT1/MRP2, respectively. Fluorescence in situ hybridization demonstrated the chromosomal locus of this gene on chromosome 17q22. The human cMOAT2 cDNA hybridized to a 6.5-kb mRNA that was mainly expressed in liver and to a lesser extent in colon, small intestine, and prostate. The cMOAT2/MRP3 gene was not overexpressed in cisplatin-resistant cell lines with increased ATP-dependent transport of cisplatin over their parental counterparts derived from human head and neck cancer and human prostatic cancer cell lines. The human cMOAT2/MRP3, a novel member of the ABC superfamily, may function as a membrane transporter in liver, colon, and prostate.

HPLC with fluorescence detection of urinary phenol, cresols and xylenols using 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride as a fluorescence labeling reagent

A simple and sensitive HPLC method for the determination of phenolic compounds, i.e., phenol (Phe), cresols (Cres) and xylenols (Xyls), was developed. After a pre-column fluorescence derivatization of these compounds with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) at 60 degrees C for 30 min, 11 DIB derivatives were successfully separated within 50 min with an ODS column using CH3CN-H2O-CH3OH (25 + 22 + 53, v/v) as the eluent. The detection limits of DIB derivatives at a signal-to-noise ratio of 3 ranged from 0.15 to 1.09 microM (0.2-1.6 pmol per 20 microliters). The precision of the proposed method for both within- and between-day assays of free and total phenol related compounds was satisfactory (RSD < 9.5%). By the proposed method, Phe and p-Cre could be detected in normal urine samples, and the calculated concentrations of free Phe and p-Cre in unhydrolysed urine samples were 1.5 +/- 1.3 and 23.9 +/- 24.3 microM and those of total Phe and p-Cre in hydrolysed urine samples were 87.3 +/- 81.2 and 200.7 +/- 195.4 microM (n = 21), respectively.

The P2 protein of rice dwarf phytoreovirus is required for adsorption of the virus to cells of the insect vector

Intact particles of rice dwarf phytoreovirus adsorbed to and entered monolayer-cultured cells of the insect vector Nephotettix cincticeps and multiplied within the cells. Particles that lacked the P2 protein neither attached to nor infected such cells. Furthermore, P2-free particles obtained from a transmission-competent isolate of the virus were unable to infect insect vectors that had been allowed to feed on these virus particles through a membrane. However, when such virus particles were injected into insects via a glass capillary tube they successfully infected the insects, which became able to transmit the virus. These results support the hypothesis that, while P2-free particles can neither interact with nor infect cells in the intestinal tract of the insect vector, they do retain the ability to infect such cells when physically introduced into the hemolymph by injection.

Tissue specific-distribution and metabolism of vitamin A are affected by dietary protein levels in rats

The effect of dietary protein levels on tissue-specific distribution and metabolism of vitamin A was studied in rats given [15-14C] retinol (14C-ROH). The weanling rats were fed a low level vitamin A diet for 10 days, then rats (15 rats per group) were divided into 2 groups; one was given a 40% casein diet as a high protein diet (HP-diet), and the other a 5% casein diet as a low protein diet (LP-diet). After 10 days feeding on these diets, 14C-ROH (5 microCi/rat) was given to both groups, HP-diet and LP-diet, by intraperitoneal injection. The radioactivity in the exhalated gases, urine and feces was measured to estimate the rate of vitamin A metabolism. The tissue specific-distribution of ROH was studied in terms of the radioactivities of the ROH fractions separated by HPLC. The hepatic 14C-ROH content in the HP-diet group was lower than that in the LP-diet group at 24, 48, and 72 hours after administration of 14C-ROH. In contrast, 14C-ROH content in serum, spleen, pancreas, and small intestinal mucosa in the HP-diet group was higher than that in the LP-diet group. The radioactivity of the exhalated gas and feces was higher in the HP-diet group. These results suggest that metabolism of vitamin A is higher with intake of a HP-diet. Thus, dietary protein levels may affect tissue-specific distribution and metabolism of vitamin A, thereby modulating the actions of this vitamin.

Relationship between gait and clinical results after high tibial osteotomy

Thirty-two patients with primary osteoarthritis of the medial compartment of the knee were studied prospectively to assess the relationship between clinical results, limb alignment, and adduction moment of the knee. Clinical and radiographic examination and gait analyses were performed preoperatively and repeated at 6 months and at 1, 3, and 6 years after high tibial osteotomy. The preoperative peak adduction moment was high in 25 patients and low in seven. In both groups, the adduction moment of the knee decreased at 6 months after surgery but increased after that period. Alignment of the affected knee in both groups remained valgus after surgery (average femorotibial angle, 167 degrees-169 degrees). Clinical outcome in both groups improved after surgery and remained unchanged after 1 year. The peak adduction moment of the knee for the whole group significantly correlated with alignment and foot angle before and 6 years after surgery but did not correlate with stride length and walking velocity. In addition, only alignment was associated significantly with clinical results at 6 years. These results suggest that the preoperative peak adduction moment of the knee does not correlate with clinical or radiographic outcomes of high tibial osteotomy, provided sufficient valgus alignment is achieved at surgery.

Isolation and characterization of homologues of plant blue-light photoreceptor (cryptochrome) genes from the fern Adiantum capillus-veneris

Many blue-light mediated physiological responses have been studied in the fern Adiantum capillus-veneris. We have isolated genomic clones encoding sequences similar to those encoding blue-light photoreceptors (cryptochromes) in higher plants using the Arabidopsis CRY1 cDNA as a probe, and these positive clones fall into five independent groups. Using RACE procedures, we obtained full-length cDNA sequences for three of these five groups. The deduced amino acid sequences include the photolyase-homologous domain in the N-terminal half, and they also contain a C-terminal extension of about 200 amino acids in length. These structural features indicate that the genes indeed encode Adiantum cryptochromes and represent a small gene family having at least three members.

Anterior spinal artery syndrome associated with severe stenosis of the vertebral artery

We describe a 55-year-old man with quadriparesis and impaired pain and temperature sensation in whom T2-weighted MR images revealed a high-intensity lesion in the cord at C3-4. Angiography showed occlusion of the right vertebral artery and severe stenosis of the left vertebral artery. We concluded that the stenosis of the vertebral artery led to the anterior spinal artery syndrome and to a disturbance of consciousness.

Expression of two angiogenic factors, vascular endothelial growth factor and platelet-derived endothelial cell growth factor in human pancreatic cancer, and its relationship to angiogenesis

Tumour angiogenesis, as assayed by microvessel density (MVD), and the expression of vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) have become established as important prognostic indicators for many tumour types. In this study, MVD and the expression of VEGF and PD-ECGF were examined by immunohistochemical staining of 50 pancreatic cancer tissues, and the relationships between either MVD or the expression of these two angiogenic factors and the clinicopathological features, including survival, were analysed. The expression of VEGF and PD-ECGF proteins were confirmed by Western blot analysis and VEGF mRNA isoforms were determined by reverse transcriptase-polymerase chain reaction (RT-PCR) in five pancreatic cancer cell lines. Twenty-eight (56%) of 50 pancreatic cancers were positive for VEGF protein in cancer cells, and 16 (32%) showed strong PD-ECGF staining in cancer and infiltrating cells. VEGF121 and VEGF165 were identified as the predominant species produced in pancreatic cancer cells. The overexpression of VEGF and PD-ECGF protein significantly correlated with high MVD (P = 0.002, 0.044, respectively). Advanced stage of disease was significantly more frequent in patients with high MVD (P = 0.025). No significant association was found between the expression of VEGF or PD-ECGF and clinicopathological features, except for tumour histology. The expression of PD-ECGF correlated with poor survival (P = 0.011), but MVD and VEGF expression were not found to be useful for the prediction of overall survival. This study suggests that VEGF and PD-ECGF may play an important role in tumour angiogenesis, and that PD-ECGF expression seems to be useful for establishing prognoses for pancreatic cancer.

Solitary plasmacytoma of the spine associated with neurological complications

We report eight patients with a solitary plasmacytoma of the spine associated with neurological complications. The patients included five men and three women with an average age at presentation of 59 years (range, 47 to 73 years). The tumour was confined to the thoracic spine in six cases, cervical spine in one and lumbar spine in one. Duration of symptoms ranged from 2.5 to 22 months. Treatment consisted of a combination of radiotherapy, melphalan and surgery. One patient progressed to multiple myeloma 7 years after surgery. Surgical treatment (anterior surgery in three cases and posterior surgery in five) produced neurological improvement in all patients. We stress the importance of an early diagnosis followed by appropriate treatment including surgery for this clinical entity and long-term follow-up to detect a disseminated disease.

The importance of initial daily administration of interferon alpha for the eradication of hepatitis C virus in patients with chronic hepatitis C: a multicenter randomized trial

BACKGROUND/AIMS

We studied the effect of initial daily administration of interferon for the treatment of chronic hepatitis C, to clarify a more effective treatment protocol for the eradication of the hepatitis C virus.

METHODOLOGY

Consecutive patients who met the inclusion criteria were randomly enrolled in two groups in this study. One hundred and five patients were randomized and assigned to two groups. Patients, who enrolled in group A, were treated with 6 million units of natural interferon-alpha given subcutaneously daily for an initial two weeks and then thrice a week for 22 weeks. Patients, who were enrolled in group B, were treated with the same dose of interferon-alpha given for 26 weeks thrice a week from the first administration.

RESULTS

In groups A and B, 58 and 47 patients were analyzed, respectively. At the end of treatment, 37 patients in group A (63.8%) had negative serum HCV-RNA test, compared with 26 in group B (55.3%), but at 6 months after discontinuation of interferon administration, 27 patients in group A (46.6%), compared with 8 in group B (21.3%). The rate of complete remission in group A (46.6%) was higher than that in group B (21.3%) (P<0.01). In patients with genotype 1b virus, the rate of complete remission was higher in group A (31.3%) than in group B (12.5%) (not significantly), and the relapse rate was lower in group A (9.4%) than in group B (37.5%), significantly (p<0.05).

CONCLUSIONS

This study suggests that initial daily interferon administration is necessary to gain a higher rate of serum HCV-RNA eradication in patients with chronic hepatitis C.

Pioglitazone enhances splanchnic glucose uptake as well as peripheral glucose uptake in non-insulin-dependent diabetes mellitus. AD-4833 Clamp-OGL Study Group

To evaluate the effect of pioglitazone on insulin resistance in non-insulin-dependent diabetes mellitus (NIDDM) patients, a double-blind placebo-controlled trial was carried out with 30 NIDDM patients. Twenty-one subjects, three on diet alone and 18 on sulfonylurea (SU), orally received 30 mg pioglitazone once daily for 12 weeks. Nine subjects, one on diet alone and eight on SU, received a matching placebo once daily for 12 weeks. Euglycemic (5.2 mmol/l) hyperinsulinemic (1200 pmol/l) clamp combined with an oral glucose load (OGL) was performed before and after 3-month treatment with pioglitazone or placebo to determine insulin-stimulated glucose disposal and splanchnic glucose uptake (SGU). No significant differences existed in the patients' characteristics, including age and body mass index, between the two study groups. The pioglitazone treatment increased the mean glucose infusion rate (GIR) prior to OGL from 8.2 +/- 2.2 to 9.2 +/- 2.0 mg/kg.min (mean +/- SD, P = 0.003) and increased the SGU rate from 28.5 +/- 19.4 to 59.4 +/- 27.1% (P = 0.010). The placebo treatment produced no significant changes in either GIR or SGU after treatment. A significant difference (P = 0.042) was observed in change of SGU between the pioglitazone and placebo treatment groups. In conclusion, the results indicate that pioglitazone is effective for ameliorating insulin resistance in NIDDM by enhancing SGU as well as peripheral glucose uptake.

An exogenous cdk inhibitor, butyrolactone-I, induces apoptosis with increased Bax/Bcl-2 ratio in p53-mutated pancreatic cancer cells

We investigated the effects of an exogenous cdk inhibitor, butyrolactone-I, on cell growth inhibition, apoptosis induction, and the regulation of apoptosis in pancreatic cancer cells with mutated p53. Cell growth was dose-dependently inhibited by Butyrolactone-I in PANC-1 and AsPC-1 cells. Phosphorylation of pRb and Cyclin A expression were significantly inhibited in Butyrolactone-I-treated cells. Apoptotic cell death was detected by both Hoechst staining and TUNEL assay. In butyrolactone-I-treated PANC-1 cells, expression of p53 protein was unchanged, but Bax expression was slightly upregulated and Bcl-2 expression was predominantly down-regulated. Bax/Bcl-2 ratio reached 9.6-fold increase compared to the control at the maximum. The time course of changes in Bax/Bcl-2 ratio was similar to that in the TUNEL-positive ratio. These data, suggest that dynamic changes of the Bax/Bcl-2 ratio might be important in determining point of apoptosis induction in pancreatic cancer cells with p53 mutation.

Prosthetic knee Candida parapsilosis infection

We report a 77-year-old man who developed Candida parapsilosis infection following total knee arthroplasty. Knee joint effusion was noted 2 weeks after surgery, and repeated cultures of aspirated fluid established the diagnosis of Candida parapsilosis infection 4 weeks after surgery. Treatment consisted of debridement and lavage of the involved joint together with continuous irrigation with fluconazole for 4 weeks, followed by oral fluconazole for another 6 months. At 3 years follow-up, the patient was doing well and radiological examination of the affected knee showed a firm attachment of the prosthesis. We suggest that early identification of the causative organism followed by continuous irrigation and use of appropriate antifungal medication may prevent joint instability and spares the removal of the prosthesis.

Cervical myeloradiculopathy with entrapment neuropathy: a study based on the double-crush concept

In an attempt to formulate a standardised approach to the diagnosis and management of patients with the double-crush syndrome, we reviewed 65 surgical cases (39 men and 26 women) with cervical myeloradiculopathy associated with entrapment neuropathy in the arm by examining the clinical features, results of nerve conduction velocity studies and distribution of the vertebral levels of compression. Fifty-three patients (average age, 43 years) presented with a carpal tunnel syndrome at the wrist and cervical lesions (41 with spondylosis and 12 with ossified posterior longitudinal ligament), while 12 had a cubital tunnel syndrome at the elbow with cervical lesions (eight with spondylosis and four with ossification of the posterior longitudinal ligament). In the former group, the lesions were found mostly at C5-6 and C6-7 levels, while in the latter group involvement of C6-7 was frequently observed. Two patients in each group required additional cervical decompression after carpal or cubital tunnel release. A retrospective review of our patients suggested that it is reasonable to pursue an accurate diagnosis followed by treatment based on individual neurological and electrophysiological findings, but taking into consideration the significant level of physical impairment associated with cord compromise, we believe that it may be reasonable to perform a cervical decompression rather than peripheral nerve release in such cases. Our findings suggest that one should be aware of a double-crush during examination of patients complaining of neck and hand problems.

Effects of dietary n-3-to-n-6 polyunsaturated fatty acid ratio on mammary carcinogenesis in rats

We investigated the effects of the dietary n-3-to-n-6 polyunsaturated fatty acid (PUFA) ratio (n-3/n-6 ratio) on mammary carcinogenesis induced by 7,12-dimethylbenz[a]anthracene in rats by feeding them several types of dietary fat with a fixed PUFA-to-saturated fatty acid ratio. Dietary fat was fed to the rats as 10% of the total feed weight, starting two weeks before the initiation. An increase in the n-3/n-6 ratio did not suppress the incidence or reduce the latency of mammary tumor development. The number and weight of mammary tumors per tumor-bearing rat tended to be large in the group with an n-3/n-6 ratio of 7.84 compared with those in the other groups. As the n-3/n-6 ratios were elevated, the total number and weight of tumors increased gradually. The prostaglandin E2 (PGE2) concentration in mammary tumor tissue was markedly low in the group with an n-3/n-6 ratio of 1.03 compared with the group with an n-3/n-6 ratio of 0.01. In addition, PGE2 concentrations were almost constant when n-3/n-6 ratios were > 1.03. These results suggested that the increase in the n-3/n-6 ratio of dietary fat with the fixed PUFA-to-saturated fatty acid ratio cannot suppress the mammary carcinogenesis but can promote development of tumors, despite reduced PGE2 concentration in the tumor.

Serum C3 content in vitamin B(12)-deficient rats

As a clue to clarifying the role of vitamin B12 (B12) in the function of the complement system, serum C3 content was determined in B12-deficient rats, and the effect of the administration of methylcobalamin (CH3-B12) on the serum C3 content was also studied. It was found that the serum C3 content in rats fed on a vitamin B12-deficient diet for 90 and 120 days significantly decreased compared with that in control rats. The administration of CH3-B12) restored the serum C3 content to control levels. The above results indicate that B12-deficiency depressed the serum C3 content and lowered humoral immunocompetence, and that these changes were ascribable to B12-deficiency.

Molecular maturation and functional expression of mouse polymeric immunoglobulin receptor

Mouse polymeric immunoglobulin receptor (pIgR) cDNA was stably introduced into a hamster-derived fibroblastic cell line, Chinese hamster ovary (CHO) cell, by the calcium phosphate method. Surface expression of pIgR was detected by immunostaining and FACS analysis. The immunoprecipitated products of cell lysates revealed that the molecular mass of the most mature form of pIgR was approximately 120 kDa. Western blotting and metabolic labeling experiments followed by immunoprecipitation with an anti-mouse secretory component (SC) Ab demonstrated the existence of a 110 kDa immature form of pIgR. The reason for the existence of two forms of pIgR molecule was examined by conducting pulse-chase experiments which revealed the pIgR underwent molecular maturation. During this process, the 110 kDa form of pIgR was converted into a 120 kDa form by glycosylation. Moreover, tunicamycin treatment revealed the core form of pIgR had a molecular mass of approximately 100 kDa. The pIgR expressed on the surface of the transfectant could specifically bind and take up mouse polymeric IgA (MOPC 315), suggesting that, at least in this mouse system, cell type-specific molecules are not necessary for surface pIgR expression and polymeric immunoglobulin (pIg) binding and uptake.

A new Drosophila ultraviolet light-damaged DNA recognition endonuclease that selectively nicks a (6-4) photoproduct site

We have previously described the purification of an ultraviolet light (UV) damage-specific DNA-binding protein from Drosophila melanogaster, designated D-DDB P1 [Nucleic Acids Res., 23 (1995) 2600-2607]. Here, we obtained highly purified D-DDB P1 from Drosophila Kc cells, and we found that D-DDB P1 is also a nuclease. D-DDB P1 can selectively bind to pyrimidine (6-4) pyrimidone photoproducts, and in the presence of Mg++, D-DDB P1 can catalyze an incision immediately on the 3' and 5' sides of the (6-4) photoproduct site.

Follicular dendritic cell tumor of the mesentery

Follicular dendritic cell (FDC) tumor is an exceedingly rare malignant neoplasm and occurs mainly in the cervical lymph nodes. We report a mesenteric FDC tumor occurring in a 66-year-old female, that manifested with intraabdominal multifocal recurrence 7 years after resection of the primary tumor. Histologically, both primary and recurrent tumors were composed of oval to spindle cells with paley eosinophilic cytoplasms, indistinct cell borders, round to elongated nuclei with clear or finely dispersed chromatin, and medium to large nucleoli. Characteristically, the tumor cells were growing in sheets, fascicles, and sometimes in whorls and a storiform pattern. In addition, focal necrosis, nuclear pleomorphism and abnormal mitoses were also observed. The neoplastic cells were intimately admixed with small lymphocytes. The diagnosis was confirmed by positive immunoreactivity with CD21 and CD35 antibodies and by ultrastructural demonstration of convoluted interdigitating cell processes connected by scattered desmosome-like junctions. Although our case showed a low proliferative activity evaluated by MIB-1, multifocal recurrence has occurred. The clinicopathologic features and differential diagnosis of FDC tumors are discussed with the review of the literature.

Changes in platelet aggregation and lipid metabolism in rats given dietary lipids containing different n-3 polyunsaturated fatty acids

We compared the effects of different n-3 polyunsaturated fatty acids (PUFA) on platelet aggregation and lipid metabolism in rats. alpha-Linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were used as n-3 PUFA sources. The rats were fed diets containing 10% lipids (polyunsaturated/saturated fatty acid (P/S) ratio = 1.0; n-3/n-6 = 0.02 for the control group, 0.2 for the test groups) for two weeks. The platelet counts, platelet aggregation, and production of thromboxane A2 (TXA2), plasma total cholesterol (TC) and triacylglycerols (TG) were not different between the ALA group and the control group, but showed a decreasing tendency for the EPA group and significant decreases for the DHA group. The production of prostacyclin in the aorta was significantly decreased in all of the n-3 PUFA groups when compared with that in the control group. Liver TC and TG concentrations were significantly decreased in the DHA group when compared with those in the control group. Based on the above, it is assumed that the physiological action exerted by n-3 PUFA differs by type and that DHA is a more effective n-3 PUFA, both for suppressing platelet aggregation and for modulating lipid metabolism in the plasma and liver of rats.