Urinary excretion of 8-oxo-7, 8-dihydro-2'-deoxyguanosine as a predictor of the development of diabetic nephropathy

AIMS/HYPOTHESIS

The increased oxidative stress in diabetes is known to contribute to the progression of diabetes and its complications. We have reported a significant relation between the content of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a product of oxidative DNA damage in urine or leukocytes and the severity of diabetic nephropathy and retinopathy [1]. We investigated whether 8-oxodG in urine or leukocytes is associated with the progression of diabetic nephropathy.

METHODS

We measured urinary 8-oxodG contents at entry and carried out a prospective longitudinal study to assess the progression of nephropathy over 5 years.

RESULTS

There was a significant progression of diabetic nephropathy in the patients with higher excretion of 8-oxodG in urine compared with the patients with moderate or lower excretion of 8-oxodG. There was no significant association between the leukocyte 8-oxodG contents and the development of nephropathy. The multivariate logistic regression analysis suggests that the urinary 8-oxodG was the strongest predictor of nephropathy among several known risk factors.

CONCLUSION/INTERPRETATION

This study provides evidence that increased oxidative stress has a primary role in the pathogenesis of diabetic nephropathy. A local enhancement of oxidative stress in diabetic kidney might explain the possible linkage between the increased urinary excretion of 8-oxodG and the development of nephropathy. 8-oxodG in urine is a useful clinical marker to predict the development of diabetic nephropathy in diabetic patients.

Alternative CUG codon usage (Ser for Leu) in Pichia farinosa and the effect of a mutated killer gene in Saccharomyces cerevisiae

The halotolerant yeast Pichia farinosa KK1 strain produces a killer toxin termed SMKT (salt-mediated killer toxin). Mass spectrometry and Edman sequencing of peptides from the mature SMKT and secreted protoxin demonstrate that positions specified by the CUG codon contain unmodified serine (Ser) in P.farinosa. In order to express the authentic SMK1 product in Saccharomyces cerevisiae, which uses the universal genetic code, the three CUG codons corresponding to Ser87, Ser137 and Ser206 in the SMK1 gene were changed to universal Ser codons by site-directed mutagenesis. The expression of the modified SMK1 gene with universal Ser codons was lethal in S.cerevisiae, as well as that of the unmodified SMK1 gene with the CUG codons. The secretion of protoxin with the authentic amino acid sequence from the modified SMK1 was significantly increased, whereas the transcription level of SMK1 was not affected in the presence or absence of CUG codon. Our results provide the first in vivo evidence that non-universal decoding of CUG is used in a hemiascomycetous yeast, P.farinosa.

Interaction of SMKT, a killer toxin produced by Pichia farinosa, with the yeast cell membranes

SMKT (salt-mediated killer toxin), a killer toxin produced by the halotolerant yeast, Pichia farinosa, kills yeasts of several genera, including Saccharomyces cerevisiae. To elucidate the killing mechanism of SMKT, we examined the interaction of SMKT with membranes using liposomes. Leakage of calcein from calcein-entrapped liposomes was observed in the presence of SMKT. Destruction of liposomes was observed by dark-field microscopy. Comparison of intact S. cerevisiae cells with SMKT-treated cells by dark-field microscopy indicated that the spherical cell membrane is disrupted by SMKT. Using sodium carbonate extraction, we obtained direct evidence for the first time that SMKT is associated with the membrane of sensitive cells. Our results indicate that SMKT kills sensitive S. cerevisiae by interacting with the yeast cell membrane.

Immunochemical and mutational analyses of P-type ATPase Spf1p involved in the yeast secretory pathway

The yeast SPF1 gene encodes a novel P-type ATPase, the substrate of which specificity has not been identified. It is required for sensitivity to SMKT, a killer toxin produced by the halotolerant yeast Pichia farinosa. To investigate the function of Spf1p, Asp487, the putative phosphorylation site of Spf1p, was replaced by Asn. Expression of the altered SPF1, with Asp487 replaced by Asn, did not suppress the SMKT-resistant phenotype of spf1 mutants, suggesting that the catalytic activity of this ATPase is required for acquisition of sensitivity to SMKT. Subcellular fractionation experiments indicated that the fractionation pattern of Spf1p was similar to that of an early Golgi protein, Och1p. Cells lacking Spf1p had an abnormal fractionation pattern of Sec12p. The spf1 disruptant also showed increased expression of Kar2p and sensitivity to tunicamycin. The glycosylation-defective phenotype and possible role of Spf1p in the secretory pathway are discussed.

Temporal bone histopathology in trisomy 22

Trisomy 22 has multiple physical anomalies, and aural malformations are commonly associated with trisomy 22. However, there has been only one report describing the temporal bone histopathology in trisomy 22. Our case is the second reported temporal bone histopathology of trisomy 22. Aural anomalies in this case were less serious than those earlier described, though showing Mondini dysplasia of the bony and membranous labyrinth. Deafness in patients with trisomy 22 may manifest sensorineural, conductive or mixed hearing losses, and/or vestibular dysfunction of varying degrees, according to the site and severity of aural anomalies.

HBe seroconversion and HBs mutation among Japanese hepatitis B virus carriers

It has been reported in Germany that seroconversion to anti-HBe or anti-HBs is frequently associated with genotype changes of hepatitis B virus (HBV) from genotype A to genotype D. We previously reported that the HBeAg-negative state in Japan was significantly more common in patients infected with genotype B HBV than those infected with genotype C HBV. To determine whether the high prevalence of genotype B in the HBeAg-negative state is due to a change from genotype C to genotype B, 72 pairs of serum samples before and after HBe seroconversion were examined for nucleotide sequences in the S gene (amino acids 42-164) among Japanese HBV carriers. No one was identified to have undergone genotype change during HBe seroconversion. A total of 71 codon mutations were observed. Sixty-two of these 71 codon mutations (87.3%) were non-synonymous. Genotype B HBV had no mutational hot spots. In genotype C, there was a mutational hot spot at amino acid 126 of the S protein, and it was suggested that Thr126 before HBe seroconversion was more susceptible to becoming an asymptomatic carrier after HBe seroconversion than Ile126. In conclusion, genotype changes during HBe seroconversion were not found to be common in Japan.

Identification and allelic frequencies of novel single-nucleotide polymorphisms in the DUSP1 and BTG1 genes

Defects in the activity of the PTEN gene, a tumor suppressor, are implicated in many types of cancer in humans. However, not all mediators of PTEN signaling pathways have been clarified, and, during efforts to identify such molecules, we previously induced expression of the DUSP1 and BTG1 genes by introducing exogenous PTEN into endometrial cancer cell lines. In the course of analyzing these two genes for mutations in ovarian carcinomas, we identified a novel single-nucleotide polymorphism (SNP) in the DUSP1 gene, and three novel SNPs in the BTG1 gene, and we have established their allelic frequencies in a Japanese population sample. These polymorphic sites will be useful for detecting losses of heterozygosity (LOH) in tumors and for examining latent associations between specific alleles and disease susceptibility.

Characteristics of the cell proliferation profile of activated rat hepatic stellate cells in vitro in contrast to their fibrogenesis activity

PURPOSE

Alterations in the kinetics of hepatic stellate cells (HSCs) after the cells are activated once have not been well documented. We investigated the characteristic profiles of cell proliferation of once-activated HSCs in contrast to the in fibrogenesis activity.

METHODS

HSCs from male Wistar rats were submitted to primary culture for 14 days and to secondary culture for 7 days. The potential for cell proliferation was evaluated by the number of the cells in G2/M phase, based on flow cytometric analysis of the cell cycle. The fibrogenesis activity was assessed by Northern blot analysis of the expression of type I and type III procollagen mRNA.

RESULTS

The number of HSCs in G2/M phase was maintained at a low level in primary culture after 6 days, while a significantly (P < 0.05) elevated number of HSCs in G2/M phase was observed on days 3 to 4. In secondary culture, the number of HSCs in G2/M phase was also consecutively maintained at a decreased level. By contrast, HSCs showed progressively increased type I and type III procollagen mRNA expression during the experimental periods of primary culture.

CONCLUSIONS

These results clearly demonstrated consecutively decreased proliferative activity, evaluated by the potential for cell mitogenesis, in once-activated HSCs, in contrast to their progressively increased fibrogenesis activity.

Endotoxin induces delayed ovulation following endocrine aberration during the proestrous phase in Holstein heifers

The effect of endotoxin on follicular growth and on secretion of LH, estradiol-17beta, progesterone and cortisol during the proestrous phase in cattle was investigated. Holstein heifers were treated with PGF2alpha at 11-13 d after ovulation to induce luteolysis. At 42 hr after PGF2alpha treatment, heifers were administered either lipopolysaccharide (LPS; Escherichia coli, O111:B4, 5 microg/kg, n = 6) or saline (control; n = 6) by i.v. bolus injection. Ovarian structures were monitored daily by transrectal ultrasonography, and blood samples were collected at various times for hormonal analysis. The duration from PGF2alpha treatment to ovulation was significantly longer in the LPS group (8.0 +/- 1.3 d) than in the control group (4.2 +/- 0.2 d). LPS significantly reduced the pulse frequency of LH for 6 hr after the administration, and increased the mean concentration and pulse amplitude of LH from 3 to 6 hr after the administration. The plasma concentrations of progesterone and cortisol were transiently increased after LPS administration. The plasma concentration of estradiol-17beta was significantly decreased at 24 hr after LPS administration compared to that in the controls. Five of six LPS-treated heifers exhibited no preovulatory LH surge until 120 hr after PGF2alpha treatment and the remaining heifer exhibited the surge at 108 hr after PGF2alpha treatment, while the LH surge was observed at 54-78 hr after PGF2alpha treatment in control heifers. These results suggest that endotoxin disrupts progression of the proestrous phase of cattle, interrupting the preovulatory estradiol rise and thus delaying the LH surge and the subsequent ovulation.

HBV-related fulminant hepatic failure: successful intensive medical therapy in a candidate for liver transplantation

Fulminant hepatic failure (FHF) usually has a fatal prognosis without liver transplantation. We describe the case of a woman who developed FHF, and was evaluated as a candidate for liver transplantation, but who was cured without transplantation through intensive medical care that included glucagon-insulin therapy, methylprednisolone pulse therapy, interferon beta and lamivudine administration, cyclosporine administration, and high-volume hemodiafiltration and plasma exchange. In a patient with FHF who is a candidate for liver transplantation but for whom the transplantation cannot be performed for some reason, intensive medical therapy, including regeneration-promoting therapy, immunosuppressive therapy, antiviral therapy, and vigorous hepatic support, should be carried out.

Observation of toroidal flow antiparallel to the <E(r) x B(straight theta)> drift direction in the hot electron mode plasmas in the compact helical system

A toroidal flow antiparallel to the <E(r) x B(straight theta)> drift direction is observed in the hot electron mode plasmas when a large positive electric field and a sharp electron temperature gradient are sustained inside the internal transport barrier in the Compact Helical System. This toroidal flow reaches up to 5x10(4) m/s at the plasma center, and it is large enough to reverse the toroidal flow driven by a tangentially injected neutral beam. These observations clearly show the plasma favors flow in the minimum nablaB direction at the transport barrier.

Temporal bone findings in multiple endocrine neoplasia type 2B

To our knowledge, present case is the first published report of temporal bone findings in multiple endocrine neoplasia type 2B (MEN-2B). We describe a 43-year-old Japanese man with medullary thyroid carcinoma (MTC), pheochromocytoma, mucosal neuroma and a Marfanoid body habitus. The collateral adrenal tumors and MTC were removed surgically. However, 14 years after surgery, the MTC and pheochromocytoma recurred and the patient died of intracranial hemorrhage due to hypertension. During the autopsy, metastatic MTC was detected in the liver, lungs, kidneys, pancreas and cervical lymph nodes. Recurrent pheochromocytoma was present in the right kidney. Mucosal neuromas were found in the tongue, gastrointestinal tract and vesical nerve plexus. The following histopathological findings were seen in both temporal bones: metastatic MTC was found as well as neuromas and the cochlear aqueduct was widely patent.

Gonadotropin-releasing hormone in third ventricular cerebrospinal fluid of the heifer during the estrous cycle

The release profile of GnRH in cerebrospinal fluid (CSF) and its correlation with LH in peripheral blood of ovary-intact heifers during the estrous cycle were investigated. A silicon catheter was placed into the third ventricle of six heifers using ultrasonography. During the mid-luteal phase, the heifers were injected with prostaglandin F(2alpha) to induce luteolysis. Surges of CSF GnRH (66.7 h after prostaglandin F(2alpha) administration) and peripheral LH (66.3 h) occurred simultaneously and were coincident with the onset of estrus (67.0 h). Duration of elevated GnRH concentration considerably overlapped with the estrous phase in each of the heifers. Mean pulse frequencies of both GnRH and LH were significantly higher during the proestrous and early luteal phases than during the mid-luteal phase, while mean concentration and pulse amplitude of both GnRH and LH were not different between these three phases. Of all the GnRH pulses identified, more than 80% were accompanied by an LH pulse during the proestrous and early luteal phases. However, the proportion of GnRH pulses that were coincident with an LH pulse during the mid-luteal phase decreased to 60%. The results clearly demonstrate that a dynamic (pulse) and longer-term (surge) changes of GnRH release into CSF are physiologically expressed during the estrous cycle in heifers, and the pattern of pulsatile GnRH secretion in heifers depends upon their estrous cycle.

Temporal bone pathology in Wegener's granulomatosis

This study aimed to demonstrate the temporal bone histopathology of two cases of Wegener's granulomatosis in which the initial symptoms were profound hearing loss and facial nerve palsy respectively. The first case, a woman of 44, suffered profound hearing loss which was remarkably improved by steroid and cyclophosphamide treatment for a time, and which seemed to be caused by invasion from granulation tissue filled in the tympanic cavity. The second case was a 61-year-old woman presenting with the facial nerve palsy. The bony canal of the horizontal portion of the facial nerve was destroyed due to granulation tissue which filled in the tympanic cavity, and granulomatous involvement was observed in the facial nerve. Wegener's granulomatosis can involve the middle ear and/or inner ear, causing hearing loss of conductive, mixed or sensorineural type. Pathogenesis of facial nerve palsy seems to be related to Wegener's granulomatous involvement of facial nerve, because the facial nerve palsy also resolved by using steroid and cyclophosphamide.

Cancer regression induced by modified CTL therapy is regulated by HLA class II and class I antigens in Japanese patients with advanced cancer

Autologous cancer-specific bulk CTLs are unlikely to be induced by in vitro CTL generation (ivtCTLG) using peripheral blood mononuclear cells (PBMCs) of cancer patients when autologous cancer cells are used as in vitro stimulators. However, autologous cancer-specific bulk CTLs are frequently activated when allogeneic cancer cells are used as in vitro stimulators, regardless of the type of cancer cell. We have developed a cancer-specific immunotherapy called modified CTL therapy, which involves adoptive immunotherapy of autologous cancer-specific bulk CTLs after active immunization of autologous or allogeneic cancer cells screened as in vitro stimulators according to their ability to induce autologous cancer-specific CTLs (ACS. CTLs). Cancer did not regress in patients in whom ACS.CTLs were not induced by ivtCTLG using the patients' PBMCs in therapy. Cancer regression, albeit temporary, occurred solely in patients under the immunological condition that ACS.CTLs were induced by ivtCTLG using PBMCs through the therapy. The induction of ACS.CTLs by ivtCTLG using patient PBMCs in therapy was related to patients' HLA class II antigens. HLA DR8 was seen more frequently in ACS.CTL-inducible patients than in ACS.CTL-uninducible patients (P=0.051). On the contrary, HLA DQ3 was seen more frequently in ACS.CTL-uninducible patients (P=0.055). On the other hand, the success in therapy, albeit temporary, was related mainly to patients' HLA class I antigens. HLA B61 was seen more frequently in patients whose therapy proved effective than in patients whose therapy proved ineffective (P=0.018). HLA Cw7 was seen more frequently in therapy-ineffective patients (P=0.040).

Open sandwich enzyme-linked immunosorbent assay for the quantitation of small haptens

The quantitation of low-molecular-weight haptens has been difficult with conventional sandwich immunoassays due to their small size. Many researchers have attempted to develop sandwich assays for haptens due to the significant advantages of the sandwich format over competitive assays including greater dynamic range, ease of automation, and sensitivity. Here we apply the open-sandwich ELISA (OS-ELISA), an immunoassay based on antigen-dependent stabilization of antibody variable regions (V(H) and V(L) domains), to hapten quantitation. Two fusion proteins, the high-affinity mutant V(H) domain from anti-4-hydroxy-3-nitrophenacetyl (NP) antibody B1-8 tethered with Escherichia coli alkaline phosphatase (V(H)(W33L)-PhoA) and the V(L) domain from the same antibody tethered with Streptococcus sp. protein G, were made. These fusion proteins when added together achieved Fv reassociation consequent to the addition of NP. Signal was generated in a direct relationship to the NP concentration with better sensitivity compared with competitive immunoassay, demonstrating this assay to be a quick noncompetitive alternative to the conventional assays for small compounds, such as environmental pollutants, drugs of abuse, and therapeutic drugs. With our previous demonstration that the OS-ELISA works well with large proteins, the OS-ELISA becomes the first practical immunoassay approach capable of quantifying any molecule regardless of their size.

A case of purpura fulminans is caused by homozygous delta8857 mutation (protein C-nagoya) and successfully treated with activated protein C concentrate

We report a Japanese patient who developed purpura fulminans and disseminated intravascular coagulation (DIC) shortly after birth. The patient was diagnosed to be homozygous for protein C deficiency and was treated with an activated protein C (APC) concentrate. Intravenous infusions of APC markedly improved the necrotic skin lesions and the anticoagulation by APC enabled successful DIC control. The identified mutation (Delta8857) results in impaired intracellular transport and protein maturation and would be the cause of the complete protein C deficiency. This is the seventh case of the mutation that has been exclusively reported in Japan, but is the first report of a homozygous case. Our findings propose new therapeutic and diagnostic tools for the management of this fatal thrombotic disease.

[Comparison of microfissures between the oval and round window niche areas in human temporal bone]

There are numerous reports on microfissures in the round window niche area, but not many reports have appeared on microfissures in the oval window niche area. In addition, few studies have compared microfissures between the oval and round window niche areas in the same subjects. Hence, the present study investigated the prevalence of microfissures in both areas in human temporal bones. The study was conducted on the 637 ears of 333 cases. Specimens were prepared according to the conventional methods: after fixation, decalcification and dehydration, each specimen was embedded in Celloidin, and the temporal bones were sectioned horizontally at 25-micron intervals. Every 10th section was stained with hematoxylin & eosin, and each section was analyzed under a light microscope. The prevalence of microfissures was analyzed in relation to the sex, left/right differences and age of the subjects. Microfissures were seen in the oval window niche area in 66.2%, and in the round window niche area in 92.0%. When a microfissure was seen in the oval window niche area, it was also detected in the round window niche area in every case. There were no sex or left/right differences in the prevalence of microfissures, and microfissures occurred bilaterally in most cases. The youngest subject with a microfissure in the oval window niche area was a 14-year-old, and the prevalence increased with age up to approximately 60 years. On the other hand, microfissures in the round window niche area were seen in a 3-year-old, and were seen in most cases over the age of ten. These findings suggest that microfissures are more likely to occur in the round window niche area as compared to the oval window niche area. However, the prevalence of microfissures in the oval window niche area was not low either, and it is important to pay attention to both the oval and round niche areas when microfissures are involved in the formation of perilymph fistulae. Given that the prevalence of microfissures in the oval window niche area increased up to about 60 years of age, not only growth, but also mastication, may be involved in the occurrence of microfissures.

Length of the eustachian tube and its postnatal development: computer-aided three-dimensional reconstruction and measurement study

Eleven normal human temporal bone-eustachian tube (ET) specimens obtained from 11 individuals whose ages were 3 months to 88 years were studied to investigate the path length along the ET lumen and its postnatal development by means of a computer-aided 3-dimensional reconstruction and measurement method. The path length of the ET lumen of the 3-month-old infant was 21.2 mm, and its growth was in correlation with age to attain its adult length (average, 37.00 +/- 4.16 mm). The ratio of the length of the cartilaginous portion together with the junctional portion to the length of the bony portion was 8:1 in an infant at the age of 3 months and 4:1 in adults. That the bony portion of the ET develops relatively more than the cartilaginous and junctional portions may cause this finding. In addition, there is a developmental shift in the orientation of the cartilaginous portion with respect to the bony portion of the ET. In children, the cartilaginous and bony portions are both aligned with the line that connects the pharyngeal orifice and the tympanic orifice. In adults, however, the cartilaginous portion is angled inferiorly and laterally from the bony portion. This change may reflect the relative growth of the face.