Apolipoprotein E2/E5 variants in lipoprotein glomerulopathy recurred in transplanted kidney

Lipid abnormalities are associated with various disorders ranging from generalized atherosclerosis to renal diseases, including lipoprotein glomerulopathy that is characterized by glomerular lipoprotein thrombi and causes type III hyperlipoproteinemia, proteinuria, and renal failure. This study examines lipoprotein glomerulopathy, which recurred in a transplanted kidney. Molecular biologic analysis of the patient's apolipoprotein (apo) E gene demonstrated E2/E5 type variants. Immunohistochemical analysis of the diseased kidney demonstrated various lipid peroxidation-specific protein adducts, suggesting a potential role of oxidative stress in this disorder. Recurrence in the transplanted kidney suggested a pathogenic role of extraglomerular humoral component(s) resulting from abnormal lipoprotein metabolism, presumably linked to apo E and other genetic or acquired factor(s). Furthermore, the finding that the patient showed pathologic abnormalities in the transplanted kidney with no clinical signs or symptoms of renal disease indicated that lipoprotein glomerular damage progresses early before any clinical manifestations.

[An elderly case of chronic inflammatory demyelinating polyneuropathy with acute onset in the course of diabetes mellitus]

A 77-year-old man was admitted because of muscle weakness in both upper and lower extremities. Diabetes mellitus was diagnosed in 1988 and he had been treated by oral hypoglycemic agents. He had a common cold at the end of January, 1997. Muscle weakness appeared in the upper extremities, followed by the lower extremities at the end of February. No sensory disturbance or dysuria was recognized. Nerve conduction study revealed distally dominant demyelinating polyneuropathy. Guillain-Barré's syndrome was diagnosed and he recovered completely following immunological absorption therapy (IAT). However, he had quadriplegia again at the end of April. He was treated by IAT combined with corticosteroid and has shown no relapse. In June, 1997, gastric cancer was detected by upper gastrointestinal fiberscopy and subtotal gastrectomy was performed. Judging from this clinical course, this case seems to be chronic inflammatory demyelinating polyneuropathy (CIDP) with acute onset. Many kinds of causes often contribute to the pathogenesis of neuropathy in the elderly. So in cases of progression or worsening, we should consider such possibilities and it is necessary not to exclude treatable causes of neuropathy.

Biological and biochemical properties of Ret with kinase domain mutations identified in multiple endocrine neoplasia type 2B and familial medullary thyroid carcinoma

Several mutations were identified in the kinase domain of the RET proto-oncogene in patients with multiple endocrine neoplasia (MEN) 2B, familial medullary thyroid carcinoma (FMTC) or sporadic medullary thyroid carcinoma. We introduced seven mutations (glutamic acid 768-->aspartic acid (E768D), valine 804-->leucine (V804L), alanine 883-->phenylalanine (A883F), serine 891-->alanine (S891A), methionine 918-->threonine (M918T), alanine 919-->proline (A919P) and E768D/A919P) into the short and long isoforms of RET cDNA and transfected the mutant cDNAs into NIH3T3 cells. The transforming activity of the long isoform of Ret with each mutation was much higher that that of its short isoform. Based on the levels of the transforming activity, these mutant RET genes were classified into two groups; a group with high transforming activity (A883F, M918T and E768D/A919P) and a group with low transforming activity (E768D, V804L, S891A and A919P) (designated high group and low group). Interestingly, the level of transforming activity correlated with clinical phenotypes; high group Ret with the A883F or M918T mutation and low group Ret with the E768D, V804L or S891A mutation were associated with the development of MEN 2B and FMTC, respectively. In addition, we found that substitution of phenylalanine for tyrosine 905 present in the kinase domain abolished both transforming and autophosphorylation activities of low group Ret whereas it did not affect the activities of high group Ret.

Histamine H2 receptor antagonism by T-593: studies on cAMP generation in Hepa cells expressing histamine H2 receptor

Histamine H2 receptor antagonism by T-593 was investigated in Hepa cells expressing canine histamine H2 receptors. T-593 inhibited generation of cAMP in Hepa cells stimulated by 10(-5) mol/l histamine with an IC50 value of 2.3 x 10(-6) mol/l, (S)-(-)-T-593, one of the enantiomers comprising racemic T-593, inhibited cAMP generation with an IC50 value of 6.1 x 10(-7) mol/l. On the other hand, the other enantiomer (R)-(+)-T-593 exhibited only a negligible effect. Incubation of the cell with (S)-(-)-T-593 for 60 min depressed the maximal response of the concentration-response curve of histamine with a nonparallel rightward shift. The slope of a Schild plot was 1.27. In contrast, (S)-(-)-T-593 caused a parallel rightward shift of the curve, with a Schild plot slope that did not significantly differ from unity, by treating the cells for 15 min. The H2 receptor-blocking action of (S)-(-)-T-593 remained almost unaffected after washing out the drug, whereas the effect of ranitidine was reversible after washing. These results suggest that T-593 possesses a time-dependent insurmountable antagonistic action against histamine H2 receptor. T-593 may interact with the histamine H2 receptor molecule in a slowly associable and dissociable manner.

Targeting endogenous platelet-derived growth factor B-chain by adenovirus-mediated gene transfer potently inhibits in vivo smooth muscle proliferation after arterial injury

Platelet-derived growth factor (PDGF), especially its B chain, has been implicated in the pathogenesis of vascular proliferative disorders such as atherosclerosis and restenosis after angioplasty. We constructed a replication-deficient recombinant adenovirus containing the gene encoding the extracellular region of PDGF beta-receptor (PDGFXR) that binds PDGF-B chain and acts as its antagonist. The administration into balloon-injured rat carotid arteries of an adenovirus containing the Escherichia coli lacZ gene as a marker gene at 5 days after injury markedly facilitated efficacy of gene transfer, as compared with its administration immediately after injury. Adenovirus-mediated gene transfer of PDGFXR into injured arteries performed at 5 days resulted in a more than 50% reduction in the neointimal area of injured arteries at 14 days. In contrast, the administration of control adenoviruses containing lacZ gene or containing no foreign gene was without suppressive effects on neointima formation. The inhibition of neointima formation by the expression of PDGFXR was accompanied by a reduction in bromodeoxyuridine-labeled cells and nearly complete inhibition of tyrosine phosphorylation of both alpha- and beta-receptors for PDGF, but not of epidermal growth factor receptor, in injured arteries. This is the first report to indicate the usefulness of targeting a growth factor by expressing an extracellular binding region of a receptor using an adenovirus for the treatment of vascular proliferative disorders, and provide direct evidence that PDGF-B chain plays an essential role in neointimal formation.

Effects of high temperature on the emergence and survival of adult Culex pipiens molestus and Culex quinquefasciatus in Japan

The emergence rate and adult survival (longevity) of Japanese strains of Culex pipiens molestus and Culex quinquefasciatus were compared at temperatures of 21, 25, and 30 degrees C. The pupation and emergence rates in both strains were higher at 21 and 25 degrees C than at 30 degrees C. The adult emergence rate, especially in females, was lower in Cx. p. molestus than in Cx. quinquefasciatus. Longevity of females and males was lower in Cx. p. molestus at 25 degrees C and above. The survival of Cx. p. molestus was adversely affected by temperatures of 28 degrees C and higher. High temperature may restrict the distribution of this species. Therefore, if Cx. p. molestus infests the Okinawa region, the likelihood that it will become established is minimal.

Influence of hemodialysis membrane type on pentosidine plasma level, a marker of "carbonyl stress"

Influence of hemodialysis membrane type on pentosidine plasma level, a marker of "carbonyl stress."

BACKGROUND

The accumulation of advanced glycation end products (AGEs) in uremia has been ascribed to the retention of carbonyl precursors of AGEs. Pentosidine plasma level has been identified as a surrogate marker of carbonyl precursors ("carbonyl stress"). The influence of hemodialysis (HD) membrane type and residual diuresis on carbonyl stress has not been studied.

METHODS

We measured protein-linked and free plasma pentosidine (a surrogate marker of carbonyl stress) by high-performance liquid chromatography in patients on HD with low-flux cellulose (N = 29), high-flux polysulfone (PS; N = 57), polymethylmethacrylate (PMMA) (N = 25), and AN69 (N = 15).

RESULTS

Both protein-linked and free pentosidine were similar on low-flux cellulose, high-flux PMMA, and AN69, but were lower (P < 0.01) on high-flux PS. Pentosidine levels were virtually identical on Fresenius and Asahi PS in Japanese and Belgian patients. By multivariate analysis, only the type of HD membrane and residual diuresis proved to be independent determinants (P < 0.001) of pentosidine levels. During a single HD session, the clearance of free pentosidine was similar with all membranes. In three patients who were switched from AN69 to PS, the protein-linked pentosidine level dropped to the control level after resumption of the AN69 membrane.

CONCLUSIONS

Both HD membrane type and residual diuresis are independent determinants of pentosidine plasma level, which is a marker of carbonyl stress.

Pathogenesis and management of dialysis-related amyloid bone disease

Dialysis-related amyloidosis (DRA) is a major complication of chronic renal failure and long-term renal replacement therapy. Beta2-Microglobulin is a major constituent of amyloid fibrils in DRA. Amyloid deposition can present as carpal tunnel syndrome, destructive arthropathy, or subchondral bone erosions and cysts. A definitive diagnosis of DRA can only be made using histological findings, but various analytical imaging methods often support diagnosis. Therapy of an established DRA is limited to symptomatic approaches and surgical removal of amyloid deposits. High-flux biocompatible dialysis membranes can be used to delay DRA development. Recent studies have suggested a pathogenic role for a new modification of beta2-microglobulin in DRA. Increased carbonyl compounds modify proteins, which leads to the augmentation of advanced glycation and lipoxidation end products. Thus, uremia might be a state of carbonyl overload with potentially damaging proteins, leading to a new modification of beta2-microglobulin in amyloid fibrils and development of DRA.

Prognosis of parathyroid function after successful percutaneous ethanol injection therapy guided by color Doppler flow mapping in chronic dialysis patients

Selective percutaneous ethanol injection therapy (PEIT) of the parathyroid glands has been shown to be effective in chronic dialysis patients with severe secondary hyperparathyroidism. In this study, we examined whether it was possible to maintain parathyroid function within target range (intact parathyroid hormone [iPTH], 160 to 360 pg/mL) in the long term after successful destruction of hyperplastic tissue. PEIT was performed in 46 patients resistant to calcitriol pulse therapy, and all glands larger than 5 mm in diameter were destroyed by ethanol, guided by power Doppler flow mapping. Serum iPTH levels decreased from 633.3 +/- 359.9 to 226.3 +/- 204.7 pg/mL at 3 weeks and were maintained at 289.9 +/- 222.4 pg/mL at 1 year after PEIT. Total alkaline phosphatase activity decreased from 384.9 +/- 160.1 to 234.0 +/- 110.5 IU/L at 1 year after PEIT. In 19 patients, iPTH levels decreased into relative hypoparathyroidism (iPTH < 160 pg/mL) at 3 weeks after PEIT; however, they recovered at 1 year after PEIT (191.1 +/- 29.6 pg/mL). Parathyroid function was maintained within target range in 80.4% of the patients at 1 year after PEIT with appropriate medical therapy. Surgical parathyroidectomy was not required in any patient. Conversely, in eight other patients with recurrent hyperparathyroidism after subtotal parathyroidectomy, iPTH levels recovered in only 50% of the patients at 1 year after PEIT. Thus, destruction of hyperplastic tissue should be optimized in such patients. Recurrent nerve palsy was observed in only one patient, but was reversible. In conclusion, selective PEIT guided by color Doppler flow mapping is an effective and safe adjunct to medical therapy with a low risk for hypoparathyroidism.

Leukotriene (LT)-receptor antagonist is more effective in asthmatic patients with a low baseline ratio of urinary LTE4 to 2,3-dinor-6-keto-prostaglandin (PG)F1alpha

BACKGROUND

To test the hypothesis that urinary levels of arachidonic acid metabolites may be a predicting factor of the effects of pranlukast, a selective leukotriene (LT) antagonist, on chronic adult asthma, we investigated the relationship between its clinical efficacy and urinary eicosanoid levels.

METHODS

An open, multicenter trial was conducted involving 38 stable moderate and severe asthmatic patients (mean percent predicted FEV1 was 71%). All patients received pranlukast (225 mg twice daily) for 4 weeks after a 2-week run-in period. Urinary levels of LTE4, 11-dehydro-thromboxane (TX) B2, 2,3-dinor-6-keto-prostaglandin (PG) F1alpha, and creatinine were measured in 3-h urine collected on day 1 of the treatment. The responder was defined by an improvement of asthma symptom scores and peak expiratory flow rate (PEFR).

RESULTS

One patient was excluded because of an adverse effect, nausea. Thirteen out of 37 subjects were responders and 24 were nonresponders. There were no significant differences in patients' backgrounds and urinary arachidonate levels between the two groups. The urinary LTE4 to 2,3-dinor-6-keto-PGF1alpha ratio in the responder was significantly lower (P=0.01) than that in the nonresponder. In all patients, a significant inverse correlation was revealed between the baseline urinary LTE4/2,3-dinor-6-keto-PGF1alpha ratio and the improvement of PEFR in the morning (r=-0.43, P=0.007).

CONCLUSIONS

These data suggested that the urinary ratio of LTE4 to 2,3-dinor-6-keto-PGF1alpha might be one of the predictive markers of the clinical efficacy of this LT-receptor antagonist in asthmatic subjects.

Age-related change in peripheral nerve conduction: compound muscle action potential duration and dispersion

BACKGROUND

We investigated the effect of age on nerve conduction parameters with special reference to the compound muscle action potential (CMAP) duration and duration ratio.

METHOD

We examined 295 subjects (aged 15-85 years old) with no previous history or present signs of peripheral neuropathy. The subjects were divided into 3 groups: young (15-34 years old); intermediate (35-64 years old), and old (65-85 years old).

RESULTS

CMAP amplitude was lower in the old group than in the young group; however, the CMAP ratio (proximal CMAP/distal CMAP) did not change with age. The CMAP duration and duration ratio did not differ among the 3 groups. The CMAP area was smaller in the old group, but the area ratio was almost constant among the 3 groups.

CONCLUSION

We suggest that age-related changes in CMAP amplitude, duration or area may occur uniformly, at least in the forearm and the calf segment, in routine nerve conduction studies. The present findings also provide useful and reliable information, regardless of age, in diagnosing peripheral neuropathy.

Abundance and distribution of bacteria carrying sltII gene in natural river water

Direct in situ PCR with HNPP/Fast Red TR was used to enumerate bacteria carrying the sltII gene in river water. By direct in situ PCR with a sltII-specific EVS primer, 10(2)-10(5) cells ml-1 of bacteria carrying the sltII gene were detected from all sampling sites, except the site nearest to the source of the river, while 10(2)-10(4) cells ml-1 of Escherichia coli O157:H7 were detected using a direct fluorescent antibody staining method. These results indicate that such bacteria are commonly distributed in natural river water. Direct in situ PCR with HNPP/Fast Red TR is a useful tool for detecting cells carrying specific genes, such as verotoxin-producing bacteria in natural environments.

p19ARF prevents G1 cyclin-dependent kinase activation by interacting with MDM2 and activating p53 in mouse fibroblasts

p19ARF encoded by the INK4a tumor suppressor gene locus functions upstream of p53 to induce cell cycle arrest. p19ARF can interact with MDM2 and p53 in cells ectopically overexpressing these three components, but the biochemical cascades from p19ARF to cell cycle arrest has not been fully elucidated. In this study, we generated stably transfected NIH3T3 cells that express exogenous p19ARF under the control of a heavy metal-inducible metalothionine promoter. Cells arrested in G1 by ectopically expressed p19ARF contained considerably reduced G1 cyclin dependent kinase (cdk2 and cdk4) activities. The expression of cyclin A (a regulatory subunit of cdk2) markedly decreased, while cyclin D1, the major cdk4 partner in fibroblasts, expressed at a slightly higher level and formed complexes with cdk2 and cdk6 in addition to cdk4. Induction of p19ARF activated p53 by increasing its stability, and allowed the expression of p21Cip1, which bound to all of the cyclin D1-cdk complexes (cyclin D1-cdk2, -cdk4, and -cdk6) thereby inhibiting their kinase activities. p19ARF formed complexes with several cellular proteins including mouse MDM2. The majority of MDM2 was found in the complex with p19ARF, while no p53 was detected in association with p19ARF. Thus, we propose that p19ARF neutralizes MDM2 by sequestration from p53, which results in activation of p53, inhibition of G1 cyclin-cdk activities, and G1 arrest.

Estimation of canine prostatic volume: nomogram based on prostatic cubic volume

To estimate prostate volume in canines, we demonstrated the nomogram based on prostatic cubic volume. Transrectal ultrasonography (TRUS) was performed in twenty beagle dogs. Prostatic length (L) and height (H) were determined on sagittal image, and prostatic width (W) was determined on transaxial image. Data of one dog, which had asymmetrical shaped prostate, were excluded from the analysis. Prostate volume was estimated by the following nomogram: Gravimetric prostatic volume (g) = 0.642 x prostatic cubic volume (cm3) + 1.84 (prostatic cubic volume = L x H x W cm3, r = 0.997, p<0.001). By substituting the prostatic height to the average of height, prostatic volume of one dog showing asymmetrical shape was successfully estimated. We also showed technical points in evaluating morphology of canine prostate on TRUS. In conclusion, this nomogram is of great use for directly estimating prostatic volume.

Inhibitory effect of thyrotropic hormone on apoptosis induced by actinomycin D in a functioning rat thyroid cell line

Apoptosis appears to play important roles in physiological and pathological processes in the endocrine system including the thyroid, but little is known about the regulation of apoptosis in the thyroid. The functioning rat thyroid cell line (FRTL-5), a cloned cell line of differentiated thyroid cells, hardly undergoes apoptosis. In this study we examined the factors which prevent FRTL-5 cells from undergoing apoptosis. After culturing FRTL-5 cells in medium with and without TSH, actinomycin D (AMD) or cycloheximide (CHX) was added. CHX did not induce apoptosis. AMD induced apoptosis in FRTL-5 cells cultured in medium lacking TSH, as confirmed by the presence of DNA fragmentation, together with nuclear fragmentation and condensation, but AMD did not induce apoptosis in FRTL-5 cells cultured in the presence of TSH. Furthermore, the fact that AMD did not induce apoptosis in FRTL-5 cells cultured with dibutyryl cyclic AMP (Bt2cAMP), or forskolin suggests that TSH has an inhibitory effect on apoptosis in FRTL-5 cells via the TSH-cAMP pathway.

Immunohistochemical evidence for an increased oxidative stress and carbonyl modification of proteins in diabetic glomerular lesions

Advanced glycation end products (AGE) include a variety of protein adducts whose accumulation has been implicated in tissue damage associated with diabetic nephropathy (DN). It was recently demonstrated that among AGE, glycoxidation products, whose formation is closely linked to oxidation, such as carboxymethyllysine (CML) and pentosidine, accumulate in expanded mesangial matrix and nodular lesions in DN, in colocalization with malondialdehyde-lysine (MDA-lysine), a lipoxidation product, whereas pyrraline, another AGE structure whose deposition is rather independent from oxidative stress, was not found within diabetic glomeruli. Because CML, pentosidine, and MDA-lysine are all formed under oxidative stress by carbonyl amine chemistry between protein amino group and carbonyl compounds, their colocalization suggests a local oxidative stress and increased protein carbonyl modification in diabetic glomerular lesions. To address this hypothesis, human renal tissues from patients with DN or IgA nephropathy were examined with specific antibodies to characterize most, if not all, carbonyl modifications of proteins by autoxidation products of carbohydrates, lipids, and amino acids: CML (derived from carbohydrates, lipids, and amino acid), pentosidine (derived from carbohydrates), MDA-lysine (derived from lipids), 4-hydroxynonenal-protein adduct (derived from lipids), and acrolein-protein adduct (derived from lipids and amino acid). All of the protein adducts were identified in expanded mesangial matrix and nodular lesions in DN. In IgA nephropathy, another primary glomerular disease leading to end-stage renal failure, despite positive staining for MDA-lysine and 4-hydroxynonenal-protein adduct in the expanded mesangial area, CML, pentosidine, and acrolein-protein adduct immunoreactivities were only faint in glomeruli. These data suggest a broad derangement in nonenzymatic biochemistry in diabetic glomerular lesions, and implicate an increased local oxidative stress and carbonyl modification of proteins in diabetic glomerular tissue damage ("carbonyl stress").

Differential effects of mental stress on plasma homovanillic acid in schizophrenia and normal controls

We previously reported that mental stress by Kraepelin's arithmetic test decreases plasma homovanillic acid (pHVA) levels in psychiatrically normal healthy human subjects. The present study was undertaken to determine whether this pattern of changes in pHVA concentrations resulting from mental stress is altered in patients with schizophrenia. Fourteen male patients with schizophrenia including those under ongoing neuroleptic treatment and 14 normal male volunteers participated in the study. Following overnight fast and restricted physical activity, the subjects performed Kraepelin's arithmetic test for 30 minutes. Plasma samples were collected immediately before and after the test for measurement of pHVA levels. A significant diagnosis by Kraepelin's test effect was observed due to a decrease in pHVA levels by the Kraepelin test in control subjects but not in patients with schizophrenia. Changes in pHVA levels during the Kraepelin test positively correlated with pre-test pHVA levels in control subjects, while this correlation was not observed in patients with schizophrenia. These results may be further support for the presence of a dopamine-dependent restitutive system in the brain. The absence of response of pHVA levels to mental stress in patients with schizophrenia may indicate that the dopamine restitutive system in these patients is disrupted or already down-regulated, as previously predicted.

Implication of expression of GDNF/Ret signalling components in differentiation of bone marrow haemopoietic cells

Glial cell line-derived neurotrophic factor (GDNF) and neurturin (NTN) mediate their actions through a unique multicomponent receptor system composed of Ret receptor tyrosine kinase and glycosyl-phosphatidylinositol-linked cell surface proteins (designated GFRalpha-1 and GFRalpha-2). In the present study, expression of these signalling components in the process of differentiation of haemopoietic cells was investigated. Ret was expressed at variable levels in normal and malignant cells of the myelomonocyte lineage. Immunohistochemical analysis of human and mouse tissues revealed that Ret expression was increased in intermediate mature myeloid cells such as promyelocytes and myelocytes and decreased in mature granulocytes and monocytes. Consistent with this observation, when THP-1 monocytic and HL-60 promyelocytic leukaemia cells expressing Ret were differentiated toward macrophages or granulocytes by treatment of 12-O-tetradecanoylphorbol-13-acetate (TPA) or all-trans retinoic acid (RA), Ret expression strikingly decreased during differentiation. Expression of GDNF, NTN, GFRalpha-1 and GFRalpha-2 was undetectable in THP-1 and HL-60 cells as well as in bone marrow haemopoietic cells. In contrast, bone marrow stromal cells appeared to express GDNF, GFRalpha-1 and GFRalpha-2 but not Ret. These findings suggested that the interaction between stromal cells and Ret-expressing haemopoietic cells in the bone marrow microenvironment may play a role in the differentiation of myelomonocyte-lineage cells through activation of the GDNF/Ret signalling pathway.

[An elderly case of juvenile muscular atrophy in the unilateral upper extremity with tremor in both hands]

A 75-year-old man had noticed muscle atrophy and weakness of his right hand and forearm at the age of 25. The symptoms slowly progressed and then stopped. Right hand tremor appeared at about age 40. There was no symptom in his left upper extremity, and his gait was normal. He now shows severe muscle atrophy in his right hand and forearm. There was distally dominant weakness of the right upper extremity and his hand grip was 0 kg on the right and 25 kg on the left. On admission there was no weakness in the bilateral lower extremities. He had postural tremor in both hands and fingers. The tendon reflexes were hypoactive in the upper extremities and normal in the lower extremities. Abnormalities in the superficial sensation were unremarkable, whereas vibration sensation in both the upper and lower extremities was mildly disturbed. Electromyography revealed chronic denervation, especially in the right upper extremity. The sensory nerve conduction study results and somatosensory evoked potentials in the upper extremities were normal. Cervical MRI demonstrated spondylotic changes, canal stenosis from the C5 to C7 levels, and compression of the spinal cord. His hand tremor was dominant on the right with a peak frequency of about 7 Hz. Tremor frequency and power were decreased by mechanical load. Hirayama's disease (juvenile muscular atrophy of unilateral upper extremity) was the most probable diagnosis, although aging might have produced various additional abnormalities. The tremor seen in this patient showed characteristics of enhanced physiological tremor.

Treatment of obstructive sleep apnea syndrome with a Kampo-formula, San'o-shashin-to: a case report

The following describes a 76-year-old male with obstructive sleep apnea syndrome successfully treated with a Kampo-formula, San'o-shashin-to (Formula medicamentorum tres ad dispellendi cordis). Polysomnography, performed before and after administration of San'o-shashin-to, revealed that the apnea index decreased from 11.1 events/hour to 4.1 events/hour, and that the apnea plus hypopnea index decreased from 18.4 events/hour to 10.7 events/hour. The patient was normo-weight (body mass index: 20.4 kg/m2), and events of sleep apnea and hypopnea were mostly noted during a non-rapid eye movement sleep. It is possible that San'o-shashin-to has some alleviating effects on the upper airway resistance during sleep.

A sensitive and specific ELISA for plasma pentosidine

BACKGROUND

Advanced glycation end products are formed by non-enzymatic glycation and oxidation reaction. Pentosidine is a well-known and characterized structure among them, and has been implicated in the pathogenesis of complications associated with chronic renal failure and long-term dialysis, such as dialysis-related amyloidosis and atherosclerosis.

METHODS

We established a highly sensitive and specific competitive enzyme-linked immunosorbent assay (ELISA) for plasma pentosidine and applied it to large numbers of plasma samples including haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients. We compared their plasma pentosidine levels determined by the competitive ELISA with those determined by high-performance liquid chromatographic (HPLC) assay currently used.

RESULTS

The plasma pentosidine levels determined by the ELISA were correlated well with those determined by sophisticated instrumental HPLC assay, both in non-diabetic and diabetic dialysis patients. Both analyses yielded comparable results, with over 8-fold higher plasma pentosidine levels in HD and CAPD patients, irrespective of the presence or absence of diabetes, as compared to normal subjects and non-uraemic diabetic patients.

CONCLUSIONS

The competitive ELISA will provide a rapid and convenient determination of plasma pentosidine content and thus be useful to assess the carbonyl stress in uraemic patients.

Implication of carbonyl stress in long-term uraemic complications

Advanced glycation end products (AGEs) are formed during non-enzymatic glycation and oxidation (glycoxidation) reactions. AGEs, such as pentosidine and carboxymethyllysine are increased in plasma proteins and skin collagen of uraemic patients several times more than in normal subjects and non-uraemic diabetic patients. However, AGEs do not differ between diabetics and non-diabetics in uraemic patients. The AGE accumulation in uraemia, therefore, cannot be attributed to hyperglycaemia, nor simply to a decreased removal by glomerular filtration of AGE-modified proteins. Recent evidence has suggested that, in uraemia, the increased carbonyl compounds, derived from both carbohydrates and lipids, modify proteins not only by glycoxidation but also by lipoxidation reactions, leading to the increased production of AGEs and advanced lipoxidation end products (ALEs). Thus, uraemia might be a state of increased carbonyl compounds with potentially damaging proteins ('carbonyl stress'). Carbonyl stress in uraemia appears relevant to long-term complications, such as dialysis-related amyloidosis. The increased AGEs and ALEs in uraemic plasma and tissue proteins may indicate alterations in the non-enzymatic chemistry involving both carbohydrates and lipids in uraemia.

2-Isopropylidenehydrazono-4-oxo-thiazolidin-5-ylacetanilide (OPB-9195) treatment inhibits the development of intimal thickening after balloon injury of rat carotid artery: role of glycoxidation and lipoxidation reactions in vascular tissue damage

We have pursued the hypothesis that the carbonyl modification of proteins by glycoxidation and lipoxidation reactions plays a role in atherogenesis. Human atherosclerotic tissues with fatty streaks and uremic arteriosclerotic tissues were examined, with specific antibodies, to detect protein adducts formed with carbonyl compounds by glycoxidation or lipoxidation reactions, i.e. advanced glycation end products (AGEs) or glycoxidation products, such as carboxymethyllysine (CML) and pentosidine, and lipoxidation products, such as malondialdehyde (MDA)-lysine and 4-hydroxy-nonenal (HNE)-protein adduct. All the four adducts were identified in the proliferative intima and in macrophage-rich fatty streaks. If the carbonyl modification is not a mere result but is a contributor to atherogenesis, inhibition of glycoxidation and lipoxidation reactions might prevent vascular tissue damage. We tested this hypothesis in rats following balloon injury of their carotid arteries, a model exhibiting a remarkable intimal thickening, which are stained positive for all the four adducts. Oral administration of 2-isopropylidenehydrazono-4-oxo-thiazolidin-5-ylacetanili de (OPB-9195), an inhibitor of both glycoxidation and lipoxidation reactions, in rats following balloon injury effectively prevented the intimal thickening. These data suggest a role for the carbonyl modification of proteins by glycoxidation and lipoxidation reactions in most, if not all, types of vascular tissue damage ('carbonyl stress'), and the usefulness of inhibitors of carbonyl reactions for the treatment of vascular tissue damage.

Treatment of stage I seminoma: should beta-HCG positive seminoma be treated aggressively?

To assess the prognostic value of beta-HCG positive stage I seminoma, clinical records of 122 patients with testicular germ cell tumour were reviewed. Fifty-five patients (mean age 38.7 years) of 122 (45.1%) had stage I seminoma. Preorchiectomy beta-HCG level was determined in 54 patients. Twenty-nine patients of 54 (53.7%) had elevated preorchiectomy beta-HCG level. No significant relationship was found in the rate of locally progressive cancer between beta-HCG positive and negative cases. Treatment consisted of radiotherapy after inguinal orchiectomy for beta-HCG negative cases, and chemotherapy or radiotherapy for beta-HCG positive cases. Tumour recurrence was found in one patient with normal beta-HCG level. Our limited series demonstrated that preorchiectomy elevated beta-HCG had no significant relationship to local tumour invasion or prognostic value. Therefore, infradiaphragmatic radiation therapy may be useful for beta-HCG positive stage I seminoma.

Alterations in nonenzymatic biochemistry in uremia: origin and significance of "carbonyl stress" in long-term uremic complications

Advanced glycation end products (AGEs), formed during Maillard or browning reactions by nonenzymatic glycation and oxidation (glycoxidation) of proteins, have been implicated in the pathogenesis of several diseases, including diabetes and uremia. AGEs, such as pentosidine and carboxymethyllysine, are markedly elevated in both plasma proteins and skin collagen of uremic patients, irrespective of the presence of diabetes. The increased chemical modification of proteins is not limited to AGEs, because increased levels of advanced lipoxidation end products (ALEs), such as malondialdehydelysine, are also detected in plasma proteins in uremia. The accumulation of AGEs and ALEs in uremic plasma proteins is not correlated with increased blood glucose or triglycerides, nor is it determined by a decreased removal of chemically modified proteins by glomerular filtration. It more likely results from increased plasma concentrations of small, reactive carbonyl precursors of AGEs and ALEs, such as glyoxal, methylglyoxal, 3-deoxyglucosone, dehydroascorbate, and malondialdehyde. Thus, uremia may be described as a state of carbonyl overload or "carbonyl stress" resulting from either increased oxidation of carbohydrates and lipids (oxidative stress) or inadequate detoxification or inactivation of reactive carbonyl compounds derived from both carbohydrates and lipids by oxidative and nonoxidative chemistry. Carbonyl stress in uremia may contribute to the long-term complications associated with chronic renal failure and dialysis, such as dialysis-related amyloidosis and accelerated atherosclerosis. The increased levels of AGEs and ALEs in uremic blood and tissue proteins suggest a broad derangement in the nonenzymatic biochemistry of both carbohydrates and lipids.

Effects of a single local administration of cilostazol on neointimal formation in balloon-injured rat carotid artery

To elucidate if locally administered cilostazol, an inhibitor of cyclic AMP phosphodiesterase III, suppresses neointimal formation in balloon-injured carotid artery of the rat, 20 mg of cilostazol was topically applied using pluronic gel at the time of balloon injury. Rats were sacrificed 14 days after balloon injury to measure the extent of neointimal formation. Plasma and tissue concentrations of cilostazol were also measured at 1, 3, 7 and 14 days after topical application. The 5-bromo-2'-deoxyuridine (BrdU, a thymidine analogue) was given intraperitoneally to detect proliferation of smooth muscle cells in the injured media at 3 days after balloon injury. At 1 day after injury, plasma and tissue concentrations were 0.147+/-0.043 microg/ml and 1380 microg/g tissue. Although the plasma concentration of cilostazol was undetectable ( < 0.02 microg/ml), a significant amount of cilostazol (46 microg/g tissue) was still detected in the tissue at the site of application even after 2 weeks. The intimal area of the injured carotid after 2 weeks was significantly smaller in the cilostazol-treated group than in the gel-treated control group (0.06+/-0.01 vs 0.15+/-0.02 mm2, P<0.001). BrdU-positive smooth muscle cells in the injured media after 3 days were also significantly fewer in the cilostazol-treated group than in the gel-treated control group (4.3+/-0.5 vs 9.1+/-0.9% of total cells, P < 0.001). These results suggest that local administration of cilostazol using pluronic gel maintains a high concentration of the drug at the application site, has an anti-proliferative effect on smooth muscle cells, and may have potential for clinical therapeutic use for the prevention of restenosis following arterial intervention.

Expression of transfected human Na+/H+ exchanger (NHE-1) in the the basolateral membrane of opossum kidney cells

Some epithelial cells have Na+/H+ exchanger (NHE) activity in both apical and basolateral membranes. Amiloride-sensitive NHE-1 is generally identified in the basolateral membrane. The renal cell line, OK7a, targets amiloride-resistant NHE predominantly to the apical membrane. It is controversial whether the transfected NHE-1 is targeted preferentially to the basolateral membrane in OK7a cells, when human NHE-1 is chronically expressed under control of constitutively active promoters. We tried to identify the membranes in which the transfected human NHE-1 could be detected following acute expression in OK7a cells. We have always observed small Na(+)-dependent pH recovery in the basolateral membrane in OK7a cells. It is, however, controversial whether or not OK7a cells express NHE activity in the basolateral membrane. We also characterized Na(+)-dependent pH recovery in the basolateral membrane. It was not inhibited by [4,4'diisothiocyanatostilbene-2,2'-disulfonic acid] (DIDS), [4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid] (SITS), or contralateral amiloride. Li+ but not K+, chol+, or NMG+ could replace Na+. These results are consistent with the presence of the NHE in the basolateral membrane. NHE activities were predominant in the apical membrane and those in both membranes were resistant to amiloride analogs. After stable transfection with human NHE-1 in a vector utilizing the metallothionein promoter, overnight induction with Zn(2+)increased the NHE activity and its sensitivity to amiloride only in the basolateral membrane in OK7a cells. We conclude that the transfected human NHE-1 is exclusively targeted to the basolateral membrane of OK7a cells during acute induction.

Effects of candesartan on the proteinuria of chronic glomerulonephritis

Angiotensin I-converting enzyme (ACE) inhibitors are commonly used for the treatment of hypertension, progressive chronic renal disease, diabetic nephropathy, and congestive heart failure. Because angiotensin II acts through membrane bound type 1 (AT1) and type 2 (AT2) receptors, ACE inhibitors and angiotensin II-receptor antagonists have distinct effects. ACE inhibitors inhibit production of angiotensin II thus suppressing the action of angiotensin II on both AT1 and AT2. In contrast, the effect of AT1-receptor antagonists is to selectively block the activation of the AT1 receptor. This AT1-receptor blockade leaves the AT2 receptors unopposed to elevated levels of endogenous angiotensin II. Thus, there may be an advantage of AT1-receptor blockade over ACE inhibition in the management of a variety of chronic vascular diseases, including chronic glomerulonephritis and other glomerular diseases. In a clinical trial candesartan, an AT1-receptor antagonist, effectively lowered urinary protein excretion in patients with chronic glomerular nephritis. Evidence indicates that functionally active AT1 receptors, as well as AT2 receptors, are present in both afferent and efferent arteriole of the glomerulus, and that angiotensin II induces afferent and efferent arteriolar dilatation via AT2 receptors.

Diagnosis, pathogenesis, and treatment of dialysis-related amyloidosis

Dialysis-related amyloidosis (DRA) is a major complication of chronic renal failure and long-term renal replacement therapy. Beta2-Microglobulin is a major constituent of amyloid fibrils in DRA. Amyloid deposition mainly involves bone and joint structures, presenting as carpal tunnel syndrome, destructive arthropathy, and subchondral bone erosions and cysts. While a definitive diagnosis of DRA can only be made by histological findings, various imaging techniques often support diagnosis. The molecular pathogenesis of this complication remains unknown. Recent studies, however, have suggested a pathogenic role of a new modification of beta2-microglobulin in amyloid fibrils, i.e. the advanced glycation end products (AGEs). Increased carbonyl compounds derived from autoxidation of both carbohydrates and lipids modify proteins in uremia, leading to augment not only AGE production but also the advanced lipoxidation end product production. Thus, uremia might be a state of carbonyl overload with potentially damaging proteins ('carbonyl stress'). Therapy of DRA is limited to symptomatic approaches and surgical removal of amyloid deposits. High-flux biocompatible dialysis membranes could be used to delay DRA development.

Ubiquitous localization of leukotriene A4 hydrolase in the rat nephron

BACKGROUND

Leukotriene (LT) B4 is a well-known inflammatory mediator and is implied to play some roles in glomerulonephritis. Although LTA4 hydrolase, a final-step key enzyme to produce LTB4, is located in glomerular mesangial cells, as well as in leukocytes, platelets, and endothelial cells, its precise distribution in the kidney other than in mesangial cells remains unknown. Therefore, we have investigated the localization of mRNA, protein, and enzyme activity of LTA4 hydrolase in the rat kidney.

METHODS

Microdissection reverse transcriptase-polymerase chain reaction was used for the determination of LTA4 hydrolase mRNA. The enzyme protein was detected by Western blot, and immunohistochemistry was performed. Finally, LTA4 hydrolase activity and LTB4 were assayed in kidney tissues.

RESULTS

LTA4 hydrolase mRNA was detectable in all microdissected nephron segments of the cortex and outer medulla. The corresponding size of approximately 70 kDa protein was shown in descending order in the inner medullary > outer medullary >/= cortical homogenates. The immunohistochemical study demonstrated the ubiquitous presence of the enzyme in all nephron segments of cortex, outer medulla, and inner collecting tubules. LTA4 hydrolase activity was detected in the inner medullary >/= outer medullary >/= cortical tissue homogenates. LTB4 was demonstrated in the inner medullary > outer medullary >/= cortical tissues during the basal condition, and was time-dependently increased by stimulation with arachidonic acid and ionomycin in the cytosolic fraction from outer medulla and in the glomerular suspension.

CONCLUSIONS

These results strongly suggest that renal tubular cells as well as glomerular cells have an LTB4-forming potency, which may participate in physiological and pathophysiological roles in the kidney.

Carbonyl compounds cross-link cellular proteins and activate protein-tyrosine kinase p60c-Src

Glyoxal, a dicarbonyl compound, is produced under oxidative stress by the autoxidation of glucose and reacts with the protein amino group to form Schiff base. In vitro treatment of murine thymocytes and fibroblasts with glyoxal induced extensive tyrosine phosphorylation of multiple proteins, which was drastically inhibited by the addition of OPB-9195, an inhibitor of the carbonyl reaction with proteins. Glyoxal induced cross-linking of a number of cellular proteins, including glycosylphosphatidylinositol (GPI)-anchored cell surface Thy-1. We then demonstrated that treatment of cells with glyoxal promptly induced activation of non-receptor protein-tyrosine kinase c-Src, which was partially inhibited by OPB-9195. It is suggested from these results that carbonyl amine reaction quickly activates c-Src, possibly through cross-linkage of GPI-anchored proteins or putative specific receptors.

Eight calves cloned from somatic cells of a single adult

Eight calves were derived from differentiated cells of a single adult cow, five from cumulus cells and three from oviductal cells out of 10 embryos transferred to surrogate cows (80 percent success). All calves were visibly normal, but four died at or soon after birth from environmental causes, and postmortem analysis revealed no abnormality. These results show that bovine cumulus and oviductal epithelial cells of the adult have the genetic content to direct the development of newborn calves.

Prevalence and renal prognosis of diagnosed autosomal dominant polycystic kidney disease in Japan

The prevalence and renal prognosis of diagnosed autosomal dominant polycystic kidney disease (ADPKD) in Japan were estimated. Hospital-based nationwide surveys were conducted in 1995. The number of ADPKD patients who visited hospitals but were not on chronic dialysis was estimated to be 10,000 (95% confidence interval: 8, 200-11,900) and that of ADPKD patients on dialysis was 4,590, yielding a prevalence of ADPKD of 117 per million population at the end of 1994 (95% confidence interval: 102-132). The prevalence increased with age and reached a peak value of 261 per million population at the age group of 55-59 years. The rate of end-stage renal disease among living patients was calculated based on the assumption that the prevalence of ADPKD in the population under the age of 55 years was 261 per million population. The rate of end-stage renal disease increased with the progression of the patients' age, reaching 49% at the age of 65-69 years and declining thereafter.

CONCLUSION

The hospital-based prevalence of ADPKD is lower than the autopsy-based prevalence, suggesting that a fairly large number of these patients do not receive medical care in their lifetime. The probability of end-stage renal disease is at most 50% among ADPKD patients who visit a hospital.

Accumulation of carbonyls accelerates the formation of pentosidine, an advanced glycation end product: carbonyl stress in uremia

Advanced glycation end product (AGE) formation is related to hyperglycemia in diabetes but not in uremia, because plasma AGE levels do not differ between diabetic and nondiabetic hemodialysis patients. The mechanism of this phenomenon remains elusive. Previously, it was suggested that elevation of AGE levels in uremia might result from the accumulation of unknown AGE precursors. The present study evaluates the in vitro generation of pentosidine, a well identified AGE structure. Plasma samples from healthy subjects and nondiabetic hemodialysis patients were incubated under air for several weeks. Pentosidine levels were determined at intervals by HPLC assay. Pentosidine rose to a much larger extent in uremic than in control plasma. Pentosidine yield, i.e., the change in pentosidine level between 0 and 4 wk divided by 28 d, averaged 0.172 nmol/ml per d in uremic versus 0.072 nmol/ml per d in control plasma (P < 0.01). The difference in pentosidine yield between uremic and control plasma was maintained in samples ultrafiltrated through a filter with a 5000-Da cutoff value and fortified with human serum albumin (0.099 versus 0.064 nmol/ml per d; P < 0.05). Pentosidine yield was higher in pre- than in postdialysis plasma samples (0.223 versus 0.153 nmol/ml per d; P < 0.05). These results suggest that a large fraction of the pentosidine precursors accumulated in uremic plasma have a lower than 5000 Da molecular weight. Addition of aminoguanidine and OPB-9195, which inhibit the Maillard reaction, lowered pentosidine yield in both uremic and control plasma. When ultrafiltrated plasma was exposed to 2,4-dinitrophenylhydrazine, the yield of hydrazones, formed by interaction with carbonyl groups, was markedly higher in uremic than in control plasma. These observations strongly suggest that the pentosidine precursors accumulated in uremic plasma are carbonyl compounds. These precursors are unrelated to glucose or ascorbic acid, whose concentration is either normal or lowered in uremic plasma. They are also unrelated to 3-deoxyglucosone, a glucose-derived dicarbonyl compound whose level is raised in uremic plasma: Its addition to normal plasma fails to increase pentosidine yield. This study reports an elevated level of reactive carbonyl compounds ("carbonyl stress") in uremic plasma. Most have a lower than 5000 Da molecular weight and are thus partly removed by hemodialysis. Their effect on pentosidine generation can be inhibited by aminoguanidine or OPB-9195. Carbonyl stress might contribute to AGE modification of proteins and thus to clinically relevant complications of uremia.

Evaluation of left ventricular early diastolic performance by color tissue Doppler imaging of the mitral annulus

A noninvasive assessment of left ventricular (LV) diastolic performance by tissue Doppler imaging was performed in 56 patients (8 patients with atypical chest pain, 42 with coronary artery disease with a previous myocardial infarction, and 6 without a previous myocardial infarction) who underwent cardiac catheterization. Mitral annular velocity (MAV) during early ventricular diastole was obtained by M-mode color tissue Doppler imaging at the posterior corner of the mitral annulus. In each patient, the negative peak of the first derivative of LV pressure decay (peak -dP/dt) and a time constant of LV relaxation (tau) were calculated from the LV pressure waves obtained by a catheter-tip micromanometer. LV end-systolic volume index was measured from contrast left ventriculography. MAV during early diastole was significantly correlated with tau (r = -0.73, p <0.001), peak -dP/dt (r = 0.58, p <0.001), and LV end-systolic volume index (r = -0.63, p <0.001). On multivariate regression analysis with MAV during early diastole, tau and LV end-systolic volume index were selected as prime determinants (r = 0.80, p <0.001). These findings suggest that MAV during early diastole has a direct relation to LV elastic recoil as well as to LV relaxation. MAV during early diastole gives important information regarding LV behavior in late systole to early diastole where LV early diastolic performance is determined.

Cyclic AMP delays G2 progression and prevents efficient accumulation of cyclin B1 proteins in mouse macrophage cells

In mouse macrophage cells, the increase of the intracellular cAMP level activates protein kinase A (PKA) and results in inhibition of cell cycle progression in both G1 and G2/M phases. G1 arrest is mediated by a cdk inhibitor, p27Kip1, which prevents G1 cyclin/cdk complexes from being activated in response to colony stimulating factor-1, whereas inhibition of G2/M progression has not been fully elucidated. In this report we analyzed the effect of cAMP on G2/M progression in a mouse macrophage cell line, BAC1.2F5A. Flow cytometric analysis and mitotic index measurement using both synchronized and asynchronized cells revealed that addition of cAMP-elevating agents (8-bromoadenosine 3':5'-cyclic monophosphate and 3-isobutyl-methyl-xanthine), although they did not affect S phase progression or M/G1 transition, temporarily arrested cells in G2 but eventually the cells proceeded to M phase, resulting in about 4 hours delay of G2 progression. Timing of cyclin B1/Cdc2 kinase activation was also retarded by about 4 hours, which was accompanied by inhibition of efficient accumulation of cyclin B1 proteins. Initial induction and accumulation of cyclin B1 mRNA were not hampered, but the half life of cyclin B1 proteins was significantly shorter during G2 phase in the presence of cAMP-elevating agents compared with that of the cells blocked from progressing through M phase by nocodazole. These results imply that the cAMP/PKA pathway regulates G2 phase progression by altering the stability of a crucial cell cycle regulator.

Significance of presence of teratomatous elements in the primary tumour of testicular cancer

To assess the tumour aggressiveness of teratoma, clinical records of patients with non-seminomatous germ cell testicular cancer were reviewed. Teratomatous elements were found in 57.8% of tumours. The rate of stage I tumours was lower in the teratoma-positive group than in the teratoma-negative group. Lymph node metastasis occurred more frequently than haematogenous metastasis in the teratoma-positive group. Tumour marker response in metastatic stage of teratoma-positive group was very excellent. Even if the radiographic response was not good, most patients were alive without disease after postchemotherapeutic salvage surgery. Furthermore, two patients with pure teratoma, who had tumour recurrence, were successfully treated with the multimodal therapy. Considering the smaller number of stage I patients in the teratoma-positive group than in the teratoma-negative group, the excellent overall response in the teratoma-positive group showed less aggressiveness of the tumour as a whole.

Noncancerous pulmonary lesions in patients with metastatic testicular germ cell cancer

By thoracoscopic surgery, we confirmed pulmonary noncancerous lesions in two patients with metastatic nonseminomatous testicular germ cell cancer. The purpose of thoracoscopic surgery was complete resection of postchemotherapeutic residual tumour in one patient or a biopsy for new lesions during chemotherapy. Histological findings were normal lymph node and pulmonary fibrosis. We demonstrated CT findings of these lesions and made some discussion on management of disseminated testicular cancer.

[Organ transplant network in Japan: current status and its role]

The Role of Organ Transplant Network are the encouragement of the organ transplantation and fair organ sharing. Its principled are united, neutral open and nonprofit organization, so as to secure the fair and quick organ sharing based on the uniform allocation policy. Japan Kidney Transplant Network was established in 1995 nad reorganized into multi-organ sharing network, Japan Organ Transplant Network in 1997, when Japan Organ transplant Act was enacted. It consists of transplant coordinators, physicians, transplant surgeons, kidney banks, local administration, academic standings, other organization/associations and others. There are several committee, in which special subjects on organ transplantation and related matters are consulted, and review system in which each case is assessed and judged. And principal and essential items are decided by the board of members and then by the general assembly. The new computer system was introduced and registrants data are renewed every year, and recipient selection is done based on the latest registrants data. Standardized HLA examination tray was introduced and class II antigen was examined by means of DNA typing since 1997, which enabled more precise and accurate search. Hereafter, the education and encouragement of transplant coordinators to raise themselves and the more effective and extended distribution of donor cards are indispensable to promote organ donation/transplantation.

Implication of the glycoxidation and lipoxidation reactions in the pathogenesis of dialysis-related amyloidosis (Review)

Dialysis-related amyloidosis is recognized as a serious bone and joint complication in long-term dialysis patients. Beta2-microglobulin has been demonstrated to be a major constituent of the amyloid fibrils. However, the molecular pathogenesis of this disorder remains unknown. Recent biochemical and immunohistological studies have identified a new modification of beta2-microglobulin in the amyloid fibrils, i.e., the advanced glycation end products (AGEs). AGEs are formed by non-enzymatic glycative and oxidative (glycoxidation) reactions. The levels of AGEs, such as pentosidine and carboxymethyllysine (CML), are elevated in both the plasma proteins and skin collagen of non-diabetic dialysis patients several times more than in normal subjects. The AGE accumulation in uremia cannot be attributed to hyperglycemia, nor simply to their decreased renal clearance. Recently, gathered evidence has suggested that, in uremia, an increase in carbonyl compounds, derived from both carbohydrates and lipids, modifies proteins, leading to the augmentation of the production of not only AGEs, but also the advanced lipoxidation end products (ALEs). Uremia might thus be a state of carbonyl overload with potentially damaging proteins ('carbonyl stress'). Immunohistochemical studies, with antibodies specific to AGEs and ALEs, identified carbonyl stress in long-lived beta2-microglobulin amyloid deposits. Furthermore, proteins modified by carbonyl stress exhibit a variety of biological activities towards several types of cells, which might partially account for dialysis arthropathies.

Trend in Chlamydia trachomatis infection among pregnant women in the past ten years in Japan: significance of Chlamydia trachomatis seroprevalence

BACKGROUND AND OBJECTIVES

Chlamydia trachomatis infection is believed to be the most common bacterial sexually transmitted disease (STD) in industrialized countries. The objective of the current study was to assess the recent trend in the prevalence of C. trachomatis in Japan.

GOAL OF THIS STUDY

To determine the trend in the seroprevalence for C. trachomatis among pregnant women in Nagasaki, Japan, during the past 10 years.

STUDY DESIGN

The seroprevalence for C. trachomatis of 9,652 pregnant women of various ages screened in 1996 and 1997 was compared with those of 275 and 297 stocked samples from 1987 and 1992, respectively. Serum antibodies to C. trachomatis were detected by the enzyme immunoassay. Prospective samples of 33 seropositive cases were also analyzed to determine kinetics of the serum antibody titer.

RESULTS

The seroprevalence has decreased in all age groups during the last 10 years. More than 70% of seropositive cases converted to be seronegative within 10 years.

CONCLUSION

The prevalence of C. trachomatis has been decreasing among Japanese pregnant women.

Translation, adaptation, and validation of the SF-36 Health Survey for use in Japan

Development of the Japanese SF-36 was completed in two phases: Phase 1: Japanese version 1.1 was produced according to International Quality of Life Assessment (IQOLA) project guidelines, but some results of psychometric tests were unexpected. First, scores varied little across physical-functioning items. Second, using factor analysis, we could not clearly distinguish the scales designed to measure the "physical" component of quality of life from those designed to measure the "mental" component. Phase 2: Focus-group discussions revealed that limited had often been interpreted as limited by a doctor. Therefore, is difficult to do was used instead (version 1.2). Results of two surveys indicated that version 1.2 yields scores that are reliable by internal consistency and test-retest standards and yields two principal components. In Japan, however, the pattern of correlations between some scales and the principal components differs from that in the United States. Iterative use of qualitative and quantitative methods was very important in developing the Japanese SF-36.

Studies on selectin blockers. 7. Structure-activity relationships of sialyl Lewis X mimetics based on modified Ser-Glu dipeptides

We have previously found that heterochiral fucodipeptides, L-Ser-D-Glu (3a) and D-Ser-L-Glu (3b), exhibited up to 20-100 times more potency than a sialyl Lewis X (sLeX, 1) and a 3'-sulfated Lewis X analogue (2) toward E-selectin binding and have also proposed, from molecular dynamics calculation, that their strong activities would depend on a possible formation of the type II and/or type II' beta-turn of compounds 3a,b (Tsukida, T.; Hiramatsu, Y.; Tsujishita, H.; Kiyoi, T.; Yoshida, M.; Kurokawa, K.; Moriyama, H.; Ohmoto, H.; Wada, Y.; Saito, T.; Kondo, H. J. Med. Chem. 1997, 40, 3534-3541). To clarify our hypothesis, we synthesized several analogues of compounds 3a,b and investigated their structure-activity relationships. As a result, it was indicated that the type II and/or type II' beta-turn conformation would be a comparatively tight form and would play important roles in favorable binding to E-selectin. These findings indicate that sLeX mimetics with type II and type II' beta-turn dipeptides could be a useful methodology for the design of an active selectin blocker.

Molecular identification of the antigens recognized by monoclonal antibody JT95 specific for thyroid carcinomas

JT95 is a monoclonal antibody (MAb) raised against the membrane fraction of differentiated thyroid carcinoma. JT95 specifically reacts to differentiated thyroid carcinoma, but not to benign thyroid tumor, normal tissue or other cancers. In this study, we purified the antigen by affinity-chromatography using MAb JT95 from spent culture medium of cell line SW1736, which was derived from a human thyroid carcinoma. The antigen was a glycoprotein having a molecular weight of 250,000 and its partial sequences obtained by peptide sequencing coincided with fibronectin. However, MAb JT95 reacted to the fibronectin purified from SW1736 but not to normal fibronectin, indicating modification of fibronectin was responsible for its antigenicity. Furthermore, immunochemical analysis of glycolipids extracted from SW1736 cells demonstrated that a second antigen was displayed on ganglioside. These results show that MAb JT95 recognized a novel antigenic epitope on a glycochain carried by both fibronectin and by a ganglioside produced by thyroid carcinoma cells.

Generation of protein carbonyls by glycoxidation and lipoxidation reactions with autoxidation products of ascorbic acid and polyunsaturated fatty acids

Accumulation of carbonyl derivatives of proteins (protein carbonyl) is taken as a biomarker of oxidative protein damage in aging and in various diseases. We detected protein carbonyls in situ in human diabetic arteriosclerotic tissues and characterized the formation of protein carbonyls. Protein carbonyls were identified in the thickened intima of arterial walls and co-localized with protein adducts formed by carbonyl amine chemistry between protein and carbonyl compounds derived from autoxidation of carbohydrates, lipids, and ascorbate, i.e. advanced glycation end products or glycoxidation products, such as carboxymethyllysine (CML) and pentosidine, and lipoxidation products, such as malondialdehyde (MDA) and 4-hydroxy-nonenal (HNE). In vitro incubation of proteins with ascorbic acid accelerated the production of protein carbonyls as well as CML and pentosidine, and incubation with arachidonate accelerated the production of protein carbonyls as well as CML, MDA, and HNE. By contrast, incubation of proteins with glucose resulted in the production of CML and pentosidine, but not protein carbonyls. Schiff base inhibitors, (+/-)-2-isopropylidenehydrazono-4-oxo-thiazolidin-5-ylace tanilide and aminoguanidine, inhibited the production of protein carbonyls after incubation with ascorbate and arachidonate. The present study suggests that ascorbate and polyunsaturated fatty acids, but not glucose, represent potential sources of protein carbonyls, and that both the glycoxidation and lipoxidation reactions contribute to protein carbonyl formation in aging and various diseases.

Autoxidation products of both carbohydrates and lipids are increased in uremic plasma: is there oxidative stress in uremia?

BACKGROUND

Advanced glycation end products (AGEs), formed by non-enzymatic glycation and oxidation (glycoxidation) reactions, have been implicated in the pathogenesis of several diseases, including normoglycemic uremia. AGE research in uremia has focused on the accumulation of carbohydrate-derived adducts generated by the Maillard reaction. Recent studies, however, have demonstrated that one AGE, the glycoxidation product carboxymethyllysine (CML), could be derived not only from carbohydrates but also from oxidation of polyunsaturated fatty acids in vitro, raising the possibility that both carbohydrate and lipid autoxidation might be increased in uremia.

METHODS

To address this hypothesis, we applied gas chromatography-mass spectrometry and high performance liquid chromatography to measure protein adducts formed in uremic plasma by reactions between carbonyl compounds and protein amino groups: pentosidine derived from carbohydrate-derived carbonyls, malondialdehyde (MDA)-lysine derived from lipid-derived carbonyls, and CML originating possibly from both sources.

RESULTS

All three adducts were elevated in uremic plasma. Plasma CML levels were mainly (>95%) albumin bound. Their levels were not correlated with fructoselysine levels and were similar in diabetic and non-diabetic patients on hemodialysis, indicating that their increase was not driven by glucose. Pentosidine and MDA-lysine were also increased in plasma to the same extent in diabetic and non-diabetic hemodialysis patients. Statistical analysis indicated that plasma levels of CML correlated weakly (P < 0.05) with those of pentosidine and MDA-lysine, but that pentosidine and MDA-lysine varied independently (P > 0.5).

CONCLUSIONS

These data suggest that the increased levels of AGEs in blood, and probably in tissues, reported in uremia implicate a broad derangement in non-enzymatic biochemistry involving alterations in autoxidation of both carbohydrates and lipids.

Effect of dual inhibition of 5-alpha-reductase and aromatase on spontaneously developed canine prostatic hypertrophy

BACKGROUND

Our aim was to assess the effect of dual inhibition of 5-alpha-reductase and aromatase on prostate glands.

METHODS

We investigated the morphological changes in the prostate gland and the changes in the hormonal environment after administration of finasteride and arimidex to intact canine specimens. The study consisted of four groups: a 5-alpha-reductase only group (5RI only, n = 5); a 5RI plus aromatase-inhibitor combination group (5RI + ARI combination, n = 5); a BPH control group (n = 3); and a castration control group (n = 3). Finasteride (1 mg/kg/day) and the same dose of arimidex were orally administered for 80 days.

RESULTS

In the 5RI group, a significant decrease in the serum dihydrotestosterone (DHT) level was found, and prostatic volume was significantly decreased. However, significant increases in serum testosterone (T) and DHT levels were observed, with a concomitant increase in prostatic volume in the 5RI + ARI combination group. Morphometric analysis showed that histopathological findings in the 5RI + ARI combination group were similar to those in the BPH control group.

CONCLUSIONS

Dual inhibition of 5-alpha-reductase and aromatase resulted in a significant increase in prostate volume, accompanied by a 3-10-fold increase in serum testosterone levels and a significant increase in testicular volume.