Localization of 67 exons on a YAC contig spanning 1.5 Mb around the multidrug resistance gene region of human chromosome 7q21.1

A contig of 21 nonchimeric yeast artificial chromosomes (YACs) was previously assembled across 1.5 Mb of the multidrug resistance (MDR) gene (PGY1 and PGY3) region of human chromosome 7q21.1. This region of the human genome has now been subjected to exon amplification to detect the presence of additional genes. Exon trapping was performed directly on the YACs. Sixty-seven gene fragments were isolated and characterized by sequence analysis and comparison with public databases. The localization of these exons in the 1.5-Mb region was determined by hybridization to YAC clones, and they were localized in 11 subregions of YAC contigs. The exon collection includes 21 exons that were identical to known cDNA sequences of PGY1, PGY3, sorcin (SRI), the cDNA similar to the delta subunit of the human amiloride-sensitive Na- channel (SCNED), and 4 cDNAs with unknown function; 43 exons that showed homology/similarity to known cDNA sequences of mouse DMP1, rat COT, mouse and human NADHD, human MDC, 3 cDNAs encoding possible membrane proteins, and 21 other cDNAs; and 3 exons that shared no homology/similarity with any sequence in public databases. The nucleotide sequences of all the PGY1 and PGY3 exons were identical to the corresponding cDNA sequences previously determined, and these exons were localized to the expected positions on the appropriate YAC clones. No other member of the MDR gene family thus appeared to be present in the 1.5-Mb region. The integrated physical and exon maps should prove valuable for both fine mapping and determination of a complete gene map of this segment of the genome.

Growth hormone-induced tyrosine phosphorylation of EGF receptor as an essential element leading to MAP kinase activation and gene expression

GH binding to its receptor, which belongs to the cytokine receptor superfamily, activates Janus kinase (JAK) 2 tyrosine kinase, thereby activating a number of intracellular key proteins such as STAT (signal transducers and activators of transcription) proteins and mitogen-activated protein (MAP) kinases, which finally lead to GH's biological actions including gene expression. In contrast to receptor tyrosine kinases, the signalling pathways leading to MAP kinase activation by GH are poorly understood but appear to involve Grb2 and Shc. We now show that GH stimulated tyrosine phosphorylation of epidermal growth factor receptor (EGFR) and its association with Grb2, and concomitantly stimulated MAP kinase activity in liver, a major target tissue. Expression of EGFR and its mutants into CHO-GH receptor (GHR) cells revealed that GH-induced full activation of MAP kinase and c-fos expression required tyrosine phosphorylation sites of EGFR but not its intrinsic tyrosine kinase activity. Moreover, by also using dominant negative JAK2 and in vitro kinase assay, we demonstrated that tyrosine 1068 of EGFR was evidently one of the major phosphorylation and Grb2 binding sites stimulated by GH via JAK2. These data suggest that the role of EGFR in GH signalling is to be phosphorylated by JAK2, thereby providing docking sites for Grb2 and activating MAP kinases and gene expression. This novel cross talk pathway may provide the first example of the hormone and cytokine receptor superfamily transducing signals via associated nonreceptor tyrosine kinase by phosphorylating growth factor receptor and utilizing it as a docking protein independent of its receptor tyrosine kinase activity.

Direct involvement of the Y-box binding protein YB-1 in genotoxic stress-induced activation of the human multidrug resistance 1 gene

The human multidrug resistance 1 (MDR1) gene encoding P-glycoprotein is often overexpressed in various human tumors after chemotherapy. During treatment with various chemotherapeutic agents, the MDR1 gene is activated at the transcriptional level and/or amplified, resulting in overexpression. Our previous studies demonstrated that an inverted CCAAT box (Y-box) might be a critical cis-regulatory element regulating UV or drug-induced MDR1 gene expression. We have now established various cell lines from human head and neck cancer KB cells which were stably transfected with the chloramphenicol acetyltransferase (CAT) reporter gene driven by various MDR1 promoter deletion constructs. Transient transfection of antisense YB-1 expression constructs resulted in a decrease of both YB-1 protein levels and DNA binding activity to the inverted CCAAT box, as determined by Western blot and gel mobility shift assays. The limited expression and binding activity due to expression of antisense YB-1 constructs were also observed when cells were treated with UV. CAT activity of constructs containing the Y-box was enhanced after treatment with UV irradiation as well as genotoxic agents such as cisplatin and etoposide. Moreover, this activation was reduced by 50-80% by transfection of antisense YB-1 expression constructs. In contrast, transfection of antisense YB-1 expression constructs had no effect on CAT activity driven by MDR1 promoter constructs not containing the Y-box. These data indicate that YB-1 is directly involved in MDR1 gene activation in response to genotoxic stress.

Interaction of rat lin-10 with brain-enriched F-actin-binding protein, neurabin-II/spinophilin

We have recently isolated a rat homologue of the Caenorrhabditis elegans lin-10 product. Although rat lin-10 is expressed in the cytosol and membrane fractions of various tissues, it is distributed only in the membrane fraction in brain where it is enriched in the synaptic plasma membrane and postsynaptic density fractions. We have isolated here a rat lin-10-interacting protein from rat brain and identified it to be neurabin-II/spinophilin, which has recently been isolated as a protein interacting with protein phosphatase I and F-actin. Neurabin-II/spinophilin is ubiquitously expressed but enriched in brain, especially in the synaptic plasma membrane and postsynaptic density fractions. We discuss the physiological significance of the interaction of rat lin-10 with neurabin-II/spinophilin.

Involvement of matrix metalloproteinase-2 activity in invasion and metastasis of pancreatic carcinoma

BACKGROUND

Activation of matrix metalloproteinase-2 (MMP-2) has been implicated in the progression, invasion, and metastasis of various cancers, but little information is available with regard to its role in pancreatic carcinoma with poor prognosis.

METHODS

Gelatin zymography was used for the detection of latent and activated forms of MMP-2 and MMP-9 in 13 normal pancreatic tissue specimens, 14 chronic pancreatitis tissue specimens, and 33 pancreatic carcinoma tissue specimens. The gelatinase activity was quantified by densitometer, and the 66-kilodalton (kDa)/(66-kDa + 72-kDa) ratio was calculated as the MMP-2 activation ratio. Western blot analysis was performed to confirm the zymographic profile.

RESULTS

Latent forms of MMP-2 and MMP-9 were detected in all samples of pancreatic carcinoma, chronic pancreatitis, and normal pancreatic tissue. The expression rate of the MMP-2 activated form in pancreatic carcinoma tissue specimens was 100% (33 of 33) but that of MMP-9 was 21%. The MMP-2 activation ratio in pancreatic carcinoma tissue specimens was significantly higher than that of chronic pancreatitis and normal pancreatic tissue specimens. The MMP-2 activation ratio in pT3 tumors was significantly higher than that in pT1 tumors. The MMP-2 activation ratio also was significantly higher in pancreatic carcinoma specimens with histologically positive regional lymph node metastasis and distant metastasis than those without metastasis. The MMP-2 activation ratio observed in patients who developed postresection recurrence within 6 months was significantly higher than that in patients without recurrence at 6 months.

CONCLUSIONS

The results of the current study indicate that MMP-2 activation plays a significant role in tumor invasion and metastasis in pancreatic carcinoma.

Involvement of matrix metalloproteinase-2 activity in invasion and metastasis of pancreatic carcinoma

BACKGROUND

Activation of matrix metalloproteinase-2 (MMP-2) has been implicated in the progression, invasion, and metastasis of various cancers, but little information is available with regard to its role in pancreatic carcinoma with poor prognosis.

METHODS

Gelatin zymography was used for the detection of latent and activated forms of MMP-2 and MMP-9 in 13 normal pancreatic tissue specimens, 14 chronic pancreatitis tissue specimens, and 33 pancreatic carcinoma tissue specimens. The gelatinase activity was quantified by densitometer, and the 66-kilodalton (kDa)/(66-kDa + 72-kDa) ratio was calculated as the MMP-2 activation ratio. Western blot analysis was performed to confirm the zymographic profile.

RESULTS

Latent forms of MMP-2 and MMP-9 were detected in all samples of pancreatic carcinoma, chronic pancreatitis, and normal pancreatic tissue. The expression rate of the MMP-2 activated form in pancreatic carcinoma tissue specimens was 100% (33 of 33) but that of MMP-9 was 21%. The MMP-2 activation ratio in pancreatic carcinoma tissue specimens was significantly higher than that of chronic pancreatitis and normal pancreatic tissue specimens. The MMP-2 activation ratio in pT3 tumors was significantly higher than that in pT1 tumors. The MMP-2 activation ratio also was significantly higher in pancreatic carcinoma specimens with histologically positive regional lymph node metastasis and distant metastasis than those without metastasis. The MMP-2 activation ratio observed in patients who developed postresection recurrence within 6 months was significantly higher than that in patients without recurrence at 6 months.

CONCLUSIONS

The results of the current study indicate that MMP-2 activation plays a significant role in tumor invasion and metastasis in pancreatic carcinoma.

[A case manifested overlapping neuropathologic features of both progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD)]

A 62-year-old man developed clumsiness, vertical ophthalmoplegia, right-side dominant parkinsonism, pyramidal signs, limb-kinetic apraxia and dementia. His brain MRI and SPECT revealed mild fronto-parietal atrophy and hypoperfusion predominately on the right side. At the age of 65, the patient died of sepsis. The duration of his illness was approximately 3 years. Clinical diagnosis was corticobasal degeneration (CBD). On neuropathological examination, there was no neuronal loss and many neurofibrillary tangles (NFTs) in the cerebral cortices. Basal ganglia and substantia nigra showed moderate to severe neuronal loss. And there were many NFTs and argyrophillic threads (threads) in the subthalamic nucleus and nuclei of the brainstem. These findings were almost compatible to those of PSP. However, the following findings were atypical for PSP, 1) mild atrophy and absence of gliosis in the tegmentum of the brain stem, 2) Mild neuronal loss in the subthalamic nucleus and the dentate nucleus without grumose degeneration. Furthermore, characteristic findings were noted on modified Gallyas-Braak stain. Numerous threads and many astrocytic plaques (AP) were shown in cerebral cortices, which were particular to CBD cases. So this case demonstrated neuropathological findings of both PSP and CBD. Therefore, it was difficult to classify this case as either PSP or CBD, and we diagnosed this case as a neuropathological overlapping case of both PSP and CBD.

New apparatus stimulating the region of tongue innervated by glossopharyngeal nerve and its application to monosodium glutamate (MSG) solution

Some apparatuses stimulating the region of tongue innervated by chorda tympani nerve were well known and they were used popularly, but the apparatuses for glossopharyngeal nerve were not produced yet. In the study, the apparatus for the stimulations of glossopharyngeal nerve was trially produced. It was known that the substance of "Umami" was responded well in the tongue region innervated by glossopharyngeal nerve. The evoked potential for the stimulations of monosodium glutamate (MSG) solution which was known as substance of Umami was measured with the use of the trial stimulating apparatus. The evoked potential was detected by monopolar lead for the positions between Cz and A1 (left lobe) with the ground at Fpz. The evoked potential of MSG consisted of a positive peak wave with the latency at approximately 250 ms. The amplitudes increased and the latency decreased as the concentration of MSG increased. The evoked potential stimulating the tongue innervated by this glossopharyngeal nerve could be detected for the first time by the use of the trial apparatus.

Involvement of matrix metalloproteinase-2 activity in invasion and metastasis of pancreatic carcinoma

BACKGROUND

Activation of matrix metalloproteinase-2 (MMP-2) has been implicated in the progression, invasion, and metastasis of various cancers, but little information is available with regard to its role in pancreatic carcinoma with poor prognosis.

METHODS

Gelatin zymography was used for the detection of latent and activated forms of MMP-2 and MMP-9 in 13 normal pancreatic tissue specimens, 14 chronic pancreatitis tissue specimens, and 33 pancreatic carcinoma tissue specimens. The gelatinase activity was quantified by densitometer, and the 66-kilodalton (kDa)/(66-kDa + 72-kDa) ratio was calculated as the MMP-2 activation ratio. Western blot analysis was performed to confirm the zymographic profile.

RESULTS

Latent forms of MMP-2 and MMP-9 were detected in all samples of pancreatic carcinoma, chronic pancreatitis, and normal pancreatic tissue. The expression rate of the MMP-2 activated form in pancreatic carcinoma tissue specimens was 100% (33 of 33) but that of MMP-9 was 21%. The MMP-2 activation ratio in pancreatic carcinoma tissue specimens was significantly higher than that of chronic pancreatitis and normal pancreatic tissue specimens. The MMP-2 activation ratio in pT3 tumors was significantly higher than that in pT1 tumors. The MMP-2 activation ratio also was significantly higher in pancreatic carcinoma specimens with histologically positive regional lymph node metastasis and distant metastasis than those without metastasis. The MMP-2 activation ratio observed in patients who developed postresection recurrence within 6 months was significantly higher than that in patients without recurrence at 6 months.

CONCLUSIONS

The results of the current study indicate that MMP-2 activation plays a significant role in tumor invasion and metastasis in pancreatic carcinoma.

Neurabin-II/spinophilin. An actin filament-binding protein with one pdz domain localized at cadherin-based cell-cell adhesion sites

In a preceding paper, we reported a novel actin filament (F-actin)-binding protein, named neurabin, which was specifically expressed in neural tissue and implicated in neurite formation. We purified from rat brain another F-actin-binding protein, which had a domain organization similar to that of neurabin but was ubiquitously expressed, and named it neurabin-II. The original neurabin, renamed neurabin-I, had 1095 amino acids and a calculated Mr of 122,729, whereas neurabin-II had 817 amino acids and a calculated Mr of 89, 642. Both neurabin-I and -II had one F-actin-binding domain at the N-terminal region, one PDZ domain at the middle region, a domain known to interact with transmembrane proteins, and domains predicted to form coiled-coil structures at the C-terminal region. Both neurabin-I and -II bound along the sides of F-actin and showed F-actin-cross-linking activity. The subcellular distribution analysis indicated that neurabin-II was enriched at the postsynaptic density fraction in rat brain and the adherens junction fraction in rat liver. Immunofluorescence microscopic analysis revealed that neurabin-II was highly concentrated at the synapse in primary cultured rat hippocampal neurons and at the cadherin-based cell-cell adhesion sites in Madin-Darby canine kidney cells. Neurabin-II turned out to be the same as a recently reported protein phosphatase 1-binding protein named spinophilin. These results suggest that neurabin-II/spinophilin plays an important role in linking the actin cytoskeleton to the plasma membrane.

Postoperative adjuvant radiotherapy and 5-fluorouracil chemotherapy for rectal carcinoma

Postoperative combined modality therapy with radiotherapy and 5-fluorouracil (5FU) chemotherapy is an effective adjuvant approach that reduces locoregional and distant metastatic disease in patients with high-risk rectal carcinoma. However, this approach results in a treatment regimen of at least 6 months' duration. The present prospective study investigates the integration of radiotherapy and 5FU chemotherapy in a protocol designed to minimize toxicity and reduce the overall treatment time. A total of 40 patients with TNM stage II or III disease received postoperative radiotherapy at four fractions per week with weekly 5FU bolus injections delivered on the fifth non-radiotherapy day. Patients also received systemic chemotherapy with leucovorin both before and after pelvic irradiation, with the total treatment duration extending for only 18 weeks. Patients were able to complete radiotherapy in 90% of cases, while the delivery of full-dose chemotherapy was achievable in the vast majority. The incidence of haematologic and gastrointestinal toxicities requiring the cessation of treatment was acceptable. With a median follow-up of 20.9 months among surviving patients, the estimated progression-free and overall survival at 2 years were 71% and 79%, respectively.

Mutations in the canilicular multispecific organic anion transporter (cMOAT) gene, a novel ABC transporter, in patients with hyperbilirubinemia II/Dubin-Johnson syndrome

Members of the ATP-binding cassette (ABC) transporter superfamily are mutated to cause diseases that include cystic fibrosis, hyperinsulinemia, adrenoleukodystrophy, Stargardt disease and multidrug resistance. We recently isolated a novel human member of ABC transporter superfamily as the candidate transporter for the glucuronide and glutathione-conjugated antitumor agents, and found it highly homologous to the rat cmoat gene. consistent with recent findings of defects in the homologous cmoat gene in two rat models of hyperbilirubinemia (TR- and Eisai), we report two deletions and a missense mutation in the active transport family signature region in the gene in patients with hyperbilirubinemia II/Dubin-Johnson syndrome (DJS; MIM 237500), respectively. These results strongly implicate the cMOAT gene as responsible for the defects in DJS patients.

NPS R-568 halts or reverses osteitis fibrosa in uremic rats

Osteitis fibrosa is a common bone injury associated with secondary hyperparathyroidism (2(o)HPT). NPS R-568 is a phenylalkylamine derivative that acts as an agonist at the cell-surface Ca2+ receptor ("calcimimetic") and inhibits parathyroid hormone (PTH) secretion. In the present study, we tested whether NPS R-568 could ameliorate osteitis fibrosa in partially nephrectomized (Nx) rats with 2(o)HPT. Six months after surgery, Nx rats had developed mild but progressive 2(o)HPT and osteitis fibrosa. Two groups of Nx rats received NPS R-568 (3 and 30 mg/kg body wt x day) by daily gavage for 30 days, which led to a dose-related decrease in serum PTH levels and to a marked reduction in peritrabecular fibrosis (0.96 +/- 0.49% to < 0.1%). Furthermore, 2(o)HPT was associated with decreases in volumetric cortical bone mineral density (vCtBMD) and in cortical bone stiffness at the femoral midshaft. NPS R-568 significantly restored the deficits in vCtBMD and stiffness. These results indicate that NPS R-568 has beneficial effects on bones with osteitis fibrosa by normalizing serum PTH levels.

Changes in circulating LH, sex steroid hormones, thyroid hormones and corticosterone in relation to breeding and molting in captive humboldt penguins (Spheniscus Humboldti) kept in an outdoor open display

Penguins are highly adapted to marine life. Their hydrodynamic efficiency depends on feathers which wear with age and need to be replaced regularly. During molting, penguins can not enter the sea to forage and are forced to fast. Therefore the duration of molting is necessarily brief. To better understand molting in penguins, we collected plasma samples from 16 (8 pairs) Humboldt penguins kept in an open display pen at Tokyo Sea Life Park from May to September, 1994 and estimated circulating concentrations of LH, testosterone, estradiol, thyroxine (T4), triiodothyronine (T3) and corticosterone. Body mass was also measured at each blood sampling. Throughout the year, reproductive activities (egg laying, incubation, hatching and rearing) and molting were observed and recorded. Humboldt penguins maintained reproductive activity from January to December except during molting. Each pair started molting between the end of July and early August; usually males started earlier. The duration of molting was 13.4 +/- 0.8 days for males and 12.9 +/- 0.3 days for females. Body masses were highest just before the start of molting in both sexes. Plasma concentrations of LH were high, (> 2 ng/ml) in May in both sexes, then gradually decreased, to 0.53 +/- 0.38 ng/ml in males and 0.72 +/- 0.11 ng/ml in females by the end of July. Testosterone and estradiol concentrations in plasma decreased and were lowest during molting. On the other hand, plasma concentrations of T4 were low until early July (ca. 20 ng/ml) and then doubled within 10 days; the high levels were maintained for one month and then decreased greatly in males and slightly in females. When the plasma concentrations of T4 started to decrease, plasma concentrations of LH increased. Changes in plasma T3 were not consistent with molting. These results indicate that the decrease of plasma levels of sex steroid hormones and the sharp increase of T4 induced molting, which lasted only for a short period.

Effect of indigestible saccharides on B lymphocyte response of intestinal mucosa and cecal fermentation in rats

The effects of water-soluble and -insoluble indigestible saccharides (IDS) on immune responses of the intestinal tract were studied. Male 4-week-old Sprague Dawley rats were fed for three weeks on diets containing several kinds of IDS at 5%. The results revealed that the proportion of kappa-light chain and IgA-presenting lymphocytes in small intestinal and cecal mucosa differed in increased number depending on the type of IDS. The response of colonic mucosa was not pronounced. The amounts of short-chain fatty acid (SCFA) and lactic acid in the cecal contents of the other test groups except the celfur group tended to be higher than those in the cellulose group, particularly in the lactulose group where many acids showed significant increases. The correlation between the proportion of kappa-light chain and IgA-presenting lymphocytes in the cecal mucosa and lactic acid in the cecal contents was significant, but that between the proportion of both lymphocytes and SCFA was not. Based on the above, we concluded that the oral administration of IDS induces the proliferation of kappa-light chain and IgA-producing B lymphocytes in small intestinal and cecal mucosa, but the degree of response differs depending on the type of IDS. It is thus suggested that IDS are involved in the intestinal immune system of rats.

Purification and characterization of NADPH-dependent carbonyl reductase, involved in stereoselective reduction of ethyl 4-chloro-3-oxobutanoate, from Candida magnoliae

A NADPH-dependent carbonyl reductase was purified to homogeneity from Candida magnoliae AKU4643 through four steps, including Blue Sepharose affinity chromatography. The enzyme catalyzed the stereoselective reduction of ethyl 4-chloro-3-oxobutanoate to the corresponding (S)-alcohol with a 100% enantiomeric excess, which is a useful chiral building block for the chemical synthesis of pharmaceuticals. The relative molecular mass of the enzyme was estimated to be 76,000 on high performance gel filtration chromatography and 32,000 on SDS polyacrylamide gel electrophoresis. The enzyme reduced alpha-, beta-keto esters and conjugated diketones in addition to ethyl 4-chloro-3-oxobutanoate. The enzyme activity was inhibited by quercetin and HgCl2, but not by EDTA. The N-terminal amino acid sequence of the enzyme showed no apparent similarity with those of other oxidoreductases.

Role of neutrophils in cerulein-induced pancreatitis in rats: possible involvement of apoptosis

We investigated the role of neutrophils and the involvement of apoptosis in cerulein-induced acute pancreatitis. Male Sprague-Dawley rats were divided into 2 groups. In the control group, acute pancreatitis was induced by subcutaneous injections of cerulein. In methotrexate-treated group, the rats received intraperitoneal injections of methotrexate to produce neutrophil depletion before the injections of cerulein. The rats were sacrificed at the indicated time points until 72 h after the first injection of cerulein. Neutrophil depletion ameliorated pancreatic edema and vacuole formation in acinar cells during the early stages of cerulein-induced acute pancreatitis. Electron microscopy, DNA gel electrophoresis and in situ nick end-labeling revealed the involvement of apoptosis in acinar cells in cerulein-induced acute pancreatitis. Furthermore, the number of apoptotic acinar cells in neutrophil-depleted rats showed an about 2-fold increase during the late stages when compared with those in the control rats. Our results suggest that neutrophil depletion in cerulein-induced pancreatitis leads to amelioration of pancreatic injury during the early stage, and enhancement of apoptosis by neutrophil depletion occurs during the late stage.

Genomic organization of the human Y-box protein (YB-1) gene

The human Y-box protein (YB-1) is a member of a family of DNA-binding proteins containing a highly conserved cold shock domain. The genomic organization of the human YB-1 gene was determined from five overlapping genomic clones that encompassed all exons of the gene. Sequence analysis of these clones revealed that human YB-1 spans approximately 19 kb of genomic DNA and contains eight exons. The cold shock domain is encoded by exons 1-5. Both exon-splitting and codon-splitting in the region of the gene encoding the cold shock domain are similar to those in the corresponding region of another Y-box binding protein, dbpA. Exon-intron structures and nucleotide sequences of the regions encoding the N-terminal and C-terminal domains of the two proteins differ markedly between YB-1 and dbpA. These observations suggest that YB-1 and dbpA arose by duplication of a common ancestral gene encoding all these domains.

Escherichia coli transformant expressing the glucose dehydrogenase gene from Bacillus megaterium as a cofactor regenerator in a chiral alcohol production system

Escherichia coli JM109 (pGDA2) overexpressing the glucose dehydrogenase (GDH) gene from Bacillus megaterium IWG3 was examined for use as a cofactor regenerator. In the asymmetric reduction of ethyl 4-chloro-3-oxobutanoate by E. coli JM109 (pKAR) which is an aldehyde reductase-overproducing transformant, E. coli JM109 (pGDA2) can act as an NADPH regenerator with NADP+ and glucose, similarly to commercially available GDH.

Parathyroid hormone suppression by 22-oxacalcitriol in the severe parathyroid hyperplasia

The suppression of parathyroid hormone (PTH) secretion by the administration of 1,25-dihydroxyvitamin D [1,25(OH)2D3] and 22-oxacalcitriol (OCT) was evaluated in nude mice transplanted with human hyperplastic parathyroid tissue. The parathyroid tissue was obtained for transplantation from a patient with severe secondary hyperparathyroidism who had undergone a parathyroidectomy. Tissue specimens were transplanted into the gluteus muscle of female nude mice. Animals were divided into two groups; one group was fed a normal diet, and the other group was fed a low calcium diet during the administration of OCT and 1,25(OH)2D3. OCT and 1,25(OH)2D3 were intraperitoneally administered two times every week, for a total of eight times. Serum calcium and phosphate levels were significantly higher in the mouse administered 1,25(OH)2D3 than in the mouse administered OCT. Serum alkaline phosphatase activity was elevated similarly in the mouse administered either OCT or 1,25(OH)2D3. OCT strongly suppressed human PTH secretion from the graft in mice with normal serum calcium levels as did 1,25(OH)2D3. However, human PTH secretion from the graft was stimulated by the administration of a low-calcium diet, despite OCT and 1,25(OH)2D3 administration. In summary, OCT and 1,25(OH)2D3 suppress PTH secretion even from severe secondary hyperplastic parathyroid tissue only in mice with normal or high calcium serum levels.

Dried green leaf powders of Jew's mellow (Corchorus), persimmon (Diosphyros kaki) and sweet potato (Ipomoea batatas poir) lower hepatic cholesterol concentration and increase fecal bile acid excretion in rats fed a cholesterol-free diet

A cholesterol-free diet containing dried powder of Jew's mellow leaves, persimmon leaves or sweet potato leaves respectively at 5% level as dietary fiber was fed to male Sprague-Dawley rats for about one month. The experiment was conducted twice except for sweet potato leaves. In the groups fed the diet mixed with powders of any of the three different dried green leaves, the hepatic cholesterol concentration significantly decreased. Such lowering was not observed in serum cholesterol concentration compared with the control (cellulose) group. A significant increase in fecal weight was observed in all the groups fed the green leaf samples. All the dried green leaves increased fecal excretion of bile acids per gram or per day compared with the control group in both experiments, but only the dried Jew's mellow leaves showed an increased excretion of neutral sterols. These results suggest that lowering of hepatic cholesterol by powdered green leaves is not necessarily due to the same factor, but to the increased fecal excretion of bile acids due to inhibited enterohepatic circulation in animals given these samples.

Relationship between radiographic classification and arthroscopic findings of articular cartilage lesions in osteoarthritis of the knee

OBJECTIVE

To examine the relationship between radiographic abnormalities and arthroscopic findings of the cartilage lesions in patients with osteoarthritis (OA) of the knee.

METHODS

Arthroscopy was performed in 190 patients with primary medial compartment (MC) OA of the knee to assess the severity of the cartilage lesion. Standing radiographs of all patients were graded according to the joint space narrowing (JSN) and Kellgren-Lawrence (K/L) scales. In addition to evaluating the correlation between arthroscopic articular cartilage lesions and the radiographic scale, multiple regression analysis was used to identify the arthroscopic findings and clinical factors that influenced the cartilage lesions.

RESULTS

The positive predictive values of the JSN and K/L scales of the MC for the presence of essentially abnormal articular cartilage in the MC by arthroscopy were high (0.98, 0.96, respectively). The sensitivity and specificity of the JSN scale and the sensitivity and negative predictive value of the K/L scale were also high in the MC. In contrast, the positive predictive values of these radiographic scales for the presence of arthroscopic lesions in the lateral compartment (LC) were poor (0.20 and 0.19). In this study population with severe OA, there were more patients with a high K/L score than with a high JSN score in the MC.

CONCLUSION

In MC-OA of the knee, the JSN and K/L scores for the MC correlated highly with cartilage lesions of the MC by arthroscopy. However, the cartilage lesion of the LC correlated poorly with both of these radiographic scales.

The 20-kilodalton (kDa) human growth hormone (hGH) differs from the 22-kDa hGH in the complex formation with cell surface hGH receptor and hGH-binding protein circulating in human plasma

In spite of recent advance in understanding of the stoichiometry of 22-kDa human GH (22K-hGH) with cell surface hGH receptor (hGHR) and hGH-binding protein (hGH-BP) circulating in human plasma, that of 20-kDa hGH (20K-hGH) is poorly understood. To clarify this, mouse pro-B Ba/F3 cells stably expressing the full-length hGHR (Ba/F3-hGHR) and both recombinant and native hGH-BP were used in this study. Cell proliferation assay revealed that the two hGH isoforms increased Ba/F3-hGHR cells to the same extent in a dose-dependent manner at 0.1 pM-10 nM. However, the self-inhibition observed in 20K-hGH at 5 microM was significantly less than that in 22K-hGH. Furthermore, addition of 1 and 10 nM recombinant hGH-BP caused a slight inhibition in 20K-hGH, but a drastic inhibition in 22K-hGH. Gel filtration chromatography of mixtures of 20K-hGH with recombinant hGH-BP clearly demonstrated that 20K-hGH formed a 1:2 (hGH:hGH-BP) complex efficiently but no detectable 1:1 complex in any conditions. Supporting data were also obtained with native hGH-BP. Computer-aided homology modeling of 20K-hGH has provided speculative data that the conformational change caused by deletion of 15 residues may occur only in the loop between helix 1 and helix 2, resulting in the reduction of its site 1 affinity. In conclusion, 20K-hGH possesses a unique property for forming a 1:2 complex to the same extent as 22K-hGH but has difficulty in forming a 1:1 complex, which might be attributed to the conformational change restricted to its site 1 region.

Clinical study of refractory apical periodontitis treated by apicectomy. Part 1. Root canal morphology of resected apex

The morphology of the root apex was analysed by observation of the anatomy of specimens obtained by apicoectomy in cases of refractory apical periodontitis that did not respond to nonsurgical root canal treatment. Apical ramifications were present in 19 (70%) of the roots, while one were found in the remaining eight (3%) roots. This frequency is far higher than that reported by other investigators, suggesting that there is a close relationship between the anatomical complexity of the root canal and the occurrence of refractory apical periodontitis.

A canalicular multispecific organic anion transporter (cMOAT) antisense cDNA enhances drug sensitivity in human hepatic cancer cells

The human cMOAT gene encodes a membrane protein involved in the ATP-dependent transport of hydrophobic compounds. To determine whether cMOAT is associated with drug sensitivity, we transfected an expression vector containing cMOAT antisense cDNA into the HepG2 human hepatic cancer cell line. We observed a reduction in cMOAT protein, as well as an enhanced level of glutathione, in the antisense transfectants. The transfectants displayed an increased sensitivity to cisplatin, vincristine, doxorubicin, and the camptothecin derivatives, (4S)-4,11-diethyl-4-hydroxy-9-[(4-piperidinopiperidino)carbonyl oxy]dione hydrochloride triethydrate and 7-ethyl-10-hydroxycamptothecin, but not to etoposide, 3-[4-amino-2-methyl-5-pyrimidinyl)methyl]-1-(2-chloroethyl)-1-nitrosoure a, 5-fluorouracil, and mitomycin C. Results suggest that cMOAT levels are inversely correlated with those of glutathione, and that cMOAT and its related genes may be involved in the sensitivity of cells to certain anticancer agents.