Haplotype and mutation analysis in Japanese patients with Wilson disease

Wilson disease (WD), an autosomal recessive disorder of copper transport, is characterized by impaired biliary excretion and by impaired incorporation of copper into ceruloplasmin. Toxic accumulation of copper causes tissue damage, primarily in the liver, brain, and kidneys. The gene for WD (ATP7B) has been cloned, and the protein product is predicted to be a copper-transporting P-type ATPase with high amino acid identity with that for Menkes disease, an X-linked disorder of copper transport. Mutation screening in WD patients has led to the identification of at least 40 mutations. In addition, haplotype analysis using three dinucleotide-repeat markers, D13S314, D13S301, and D13S316, has been a useful indicator of specific mutations. We have determined haplotypes for the patients and their parents and sibs, in 21 unrelated WD families from Japan. Twenty-eight different haplotypes were observed on 42 WD chromosomes. In all the patients, the ATP7B coding sequence, including the intron-exon boundaries, was screened for mutations, by SSCP, followed by direct-sequence analysis of the shifted fragments. We identified 13 mutations, of which 11 mutations are novel, including 7 mutations-1 insertion, 4 deletions, and 2 missense mutations-in the coding region. The mutations reported in previous studies are 2299insC and Arg778Leu. Two patients were shown to have the 2299insC mutation, which has occurred in many different haplotypes in several populations, indicating a mutation hot spot. Primer-extension analysis of ATP7B mRNA has revealed multiple transcription start sites. Four of the novel mutations (three 1-bp changes and one 5-bp deletion) occur in the 5' UTR and may result in altered expression of the WD gene.

mRNA distribution and membrane localization of the OAT-K1 organic anion transporter in rat renal tubules

OAT-K1, a renal organic anion transporter, which mediates methotrexate uptake, was analyzed for mRNA distribution along microdissected nephron segments and the immunolocalization in isolated plasma membranes from rat kidney. By using a reverse transcription-coupled PCR, OAT-K1 mRNA was detected predominantly in the superficial and juxtamedullary proximal straight tubules. Western blotting with antiserum for OAT-K1 revealed that the transporter protein with the apparent molecular mass of 40 kDa was expressed exclusively in the brush-border membranes from rat kidney. These findings suggest that the OAT-K1 is localized in the brush-border membranes of the renal proximal straight tubules.

Evaluation of renal tubular secretion and reabsorption of levofloxacin in rats

PURPOSE

Levofloxacin, a quinolone antibacterial drug, is a zwitterion at physiological pH. We examined the effect of cationic and anionic drugs on renal excretion of levofloxacin by means of in vivo clearance to characterize the mechanisms of renal excretion of this drug.

METHODS

In vivo clearance was studied in male Wistar albino rats. A bolus dose of 2.85 mg/kg of levofloxacin was administered, followed by a constant infusion of 7.08 micrograms/min. Cimetidine, tetraethylammonium, or p-aminohippurate was administered as a bolus and incorporated into the infusion solution. After reaching steady state, urine and blood concentrations were measured, and pharmacokinetic parameters were calculated.

RESULTS

Renal clearance was 2.56 +/- 0.42 ml/min in control, which accounted for 34% of the total body clearance. Renal clearance was significantly decreased to 0.83 +/- 0.25 ml/min by cimetidine (p < .05), corresponding to 32% of the control value. The cationic drug, tetraethyl-ammonium also reduced the renal clearance of levofloxacin, but the effect of the anionic drug, p-aminohippurate, was slight. The clearance ratio of levofloxacin, which was calculated by renal clearance divided by the plasma unbound fraction and the glomerular filtration rate, was 1.60 +/- 0.38 in the control and it was decreased to 0.68 +/- 0.17 and 1.11 +/- 0.22 by cimetidine and tetraethylammonium, respectively.

CONCLUSIONS

The present results suggest that the renal excretion of levofloxacin in rats involves tubular secretion and reabsorption, in addition to glomerular filtration, and that tubular secretion is inhibited by cimetidine.

Relationship between expression level of P-glycoprotein and daunorubicin transport in LLC-PK1 cells transfected with human MDR1 gene

P-Glycoprotein-mediated transcellular transport and intracellular accumulation of [3H]daunorubicin were examined in cell monolayers with different levels of P-glycoprotein. The porcine kidney epithelial cell line LLC-PK1 was transfected with MDR1 cDNA, and four sublines, LLC-GA5, LLC-GA5-VLB4, LLC-GA5-COL10, and LLC-GA5-COL150, were obtained by culturing the cells in the absence or in the presence of 4 ng/mL vinblastine, 10 ng/mL colchicine, and 150 ng/mL colchicine, respectively. Western blot analysis showed a large difference in P-glycoprotein expression within these sublines. The degree of drug resistance was dependent on the expression level of P-glycoprotein. The amount of the unidirectional transport of [3H]daunorubicin by P-glycoprotein corresponded to the expression level of P-glycoprotein, which was followed by the decrease in intracellular accumulation of the agent. The concentration of cyclosporin A required for the inhibition of P-glycoprotein-mediated transport of [3H]daunorubicin was higher in cells with a high expression of P-glycoprotein. These findings suggest that the transport of daunorubicin by P-glycoprotein and its inhibition by cyclosporin A correspond to the expression level of P-glycoprotein.

Bentall operation for a child with Marfan syndrome: a case report

Children with Marfan syndrome rarely undergo surgery for annuloaortic ectasia and aortic regurgitation in the first decade. A 7-year-old girl presented with congestive heart failure due to severe aortic regurgitation associated with annuloaortic ectasia (6 cm). She also had funnel chest. She underwent a Bentall operation and sternal turn-over with a satisfactory result. Since the aortic valve cusps had rolled edges, the aortic valve was not spared. Histology of the aortic valve cusps showed myxoid degeneration and fragmentation of elastic fibers.

Molecular form and subcellular distribution of acid beta-galactosidase in fibroblasts from patients with GM1 gangliosidosis, Morquio B disease and galactosialidosis

The molecular form and subcellular distribution of acid beta-galactosidase in cultured fibroblasts from patients with beta-galactosidase deficiency (GM1-gangliosidosis, Morquio B disease and galactosialidosis) were studied, using antibodies against three different forms of the human enzyme: a high-molecular-weight multienzymic complex, a recombinant 84-kDa precursor, and a 64-kDa tryptic product of the precursor. The mature enzyme from normal fibroblasts was immunoprecipitated by the anti-complex and anti-64-kDa protein antibodies, but not by the anti-84-kDa precursor one. immunofluorescence staining of normal fibroblasts revealed the granular (lysosomal) distribution with anti-64-kDa protein antibody and the perinuclear reticular distribution with anti-84-kDa precursor antibody, probably representing the Golgi apparatus. Both patterns were demonstrated in Morquio B disease, but the residual enzyme activity was exclusively due to the mature enzyme. In Type 1 galactosialidosis, most of the expressed enzyme was detected as the precursor form with a perinuclear reticular distribution. In type 2 galactosialidosis, more than half of the enzyme activity was due to the mature form with a lysosomal distribution. Fibroblasts from a patient with GM1 gangliosidosis, expressing no beta-galactosidase mRNA, did not react against either anti-64-kDa protein antibody or anti-84-kDa precursor antibody. The combined use of immunoprecipitation and immunostaining was useful for analysing the pathophysiology of the intracellular processing and transport of the mutant beta-galactosidase.

[The studies of extracorporeal shock wave lithotripsy (ESWL) for pancreatic ductal stones]

30 patients with main pancreatic duct stones were treated by ESWL. In 18 of 22 patients who had not previously undergone endoscopic pancreatic sphincterotomy (EPST) or endoscopic sphincterotomy (EST), the stone fragments disappeared after ESWL. The fragments were removed endoscopically in the remaining 4 cases. Complete clearance was achieved in 8 cases with endoscopically unextractable stones by ESWL. After the ESWL procedure, absolute relief from pain was reported by in 19 of 22 patients with abdominal complaints. Serum amylase levels decreased significantly, and dilatation of the main pancreatic duct (MPD) was reduced. In the medium-term follow-up period, pancreatic exocrine function and endocrine function had a possibility to be preserved. One case of pancreatic cancer and one case of an intraductal papillary tumor of the pancreas were found, indicating that careful observation is necessary even after complete removal of pancreatic stones. In cases of Santorini duct dominant, multiple stones, or stricture of the MPD, ESWL should be combined with EPST and endoscopic stenting for preventing recurrence of acute pancreatitis and pancreatic stones. In conclusion, ESWL is the first choice of treatment for pancreatolithiasis and useful procedure and the limited complications.

Renal excretion of vancomycin in rats with acute renal failure

We have investigated the renal excretion of vancomycin in rats with acute renal failure (ARF) induced by uranyl nitrate or cisplatin. The renal clearance of the antibiotic after uranyl nitrate or cisplatin injection was separately evaluated by calculating the glomerular filtration rate (GFR) and secretory clearance. The reduced renal clearance of vancomycin in these ARF rats was a result of a decrease in both GFR and secretory clearance. The extents of the decreases in GFR and in secretory clearance were not, however, proportional, the extent of the decrease in secretory clearance being more pronounced. These results suggest that the renal tubular secretion of vancomycin was reduced more predominantly than glomerular filtration in these ARF models.

Intercostal hemangioma

Chest wall tumors are uncommon and there have been only a few reports of intercostal hemangioma during the past 20 years. We treated a 33-year-old man who presented with intercostal hemangioma. We resected tumor and surrounding muscles beyond the limits of the lesion without removing any bone or lung tissue. The patient is free of any recurrence 3 years after surgery.

Allele frequencies of intragenic, and 5' and 3' markers of the dystrophin gene in Japanese families afflicted with Duchenne or Becker muscular dystrophy

Using the polymerase chain reaction method (PCR), we examined the allele frequencies and heterozygosities of 7 polymorphic sites (pERT87, and CA polymorphisms in the 5' and 3' regions) of the dystrophin gene in 20 Japanese Duchenne muscular dystrophy and Becker muscular dystrophy (DMD or BMD) families consisting of 36 males, including 23 cases of DMD and BMD, and 28 females. The allele frequencies of three primer and enzyme sets in the pERT87 locus were well comparable to those in the previously reported Japanese female cases but different from in other countries. The frequencies of 5' markers of the dystrophin gene in Japanes were different from the reported Caucasian frequencies. As for 5'DYS-I and 5'DYS-II, the numbers of alleles in our cases were less than in Caucasians, and the heterozygosities of all three markers (5'DYS-I, II and III) were lower than in Caucasians. However, the 3'CA polymorphisms showed almost the same frequencies and heterozygosities as in Caucasians. All of our females showed a heterozygous pattern for at least one locus, with the combination of the seven markers. The usefulness of linkage analysis involving PCR methods with these intragenic, and 5' and 3' markers of the dystrophin gene in the carrier and prenatal diagnosis of DMD and BMD was confirmed by the successful prenatal diagnoses in 15 fetuses, the exception being one case considered to have a new mutation.

In-vivo clearance study of vancomycin in rats

The renal handling of vancomycin in rats and the effects of various drugs (probenecid, cimetidine and quinidine) on urinary excretion of the antibiotic were investigated by in-vivo clearance. The vancomycin-to-inulin excretion ratio (ER) was greater than unity at various infusion rates of vancomycin. Quinidine, co-administered with vancomycin, significantly decreased the total, renal and net secretory clearance of the antibiotic. Cimetidine also decreased, though not significantly, the secretory clearance of vancomycin by about 20%, but probenecid did not. These results suggested that vancomycin is secreted in renal tubules in rats, and that quinidine decreases the total clearance of vancomycin partly by inhibiting its tubular secretion in the kidney.

Na(+)-dependent uptake of 1,5-anhydro-D-glucitol via the transport systems for D-glucose and D-mannose in the kidney epithelial cell line, LLC-PK1

1,5-Anhydro-D-glucitol, a 1-deoxy form of D-glucose, is one of the major polyols in human and rat blood plasma, and is regarded as a sensitive marker of glycemic control in diabetic patients. Although renal tubular reabsorption of 1,5-anhydro-D-glucitol is thought to maintain the physiological plasma level of this polyol, the mechanism of its cellular uptake has not yet been established. In the present study, the transport characteristics of 1,5-anhydro-D-glucitol in a kidney epithelial cell line, LLC-PK1, were investigated. The uptake of 1,5-anhydro-D-glucitol by the LLC-PK1 cell monolayers was found to be a highly Na(+)-dependent process. The initial uptake rate of 1,5-anhydro-D-glucitol was inhibited by the presence of D-glucose, D-mannose and methyl-alpha-D-glucoside, a nonmetabolizable D-glucose analogue. D-Mannose was taken up partially by LLC-PK1 cells in a Na(+)-dependent manner. 1,5-Anhydro-D-glucitol had an inhibitory effect on the uptake of both methyl-alpha-D-glucoside and D-mannose. Phlorizin inhibited the uptake of methyl-alpha-D-glucoside and 1,5-anhydro-D-glucitol, but not of D-mannose. In contrast, phloretin inhibited the uptake of both 1,5-anhydro-D-glucitol and D-mannose, but not the uptake of methyl-alpha-D-glucoside. The apparent Michaelis-Menten constant and maximum velocity values for 1,5-anhydro-D-glucitol uptake were 29 mM and 240 pmol/mg protein/min, respectively. These findings suggest that the uptake of 1,5-anhydro-D-glucitol across the apical membranes of LLC-PK1 cells is mediated by the Na(+)/D-glucose cotransport system and probably by the Na+/D-mannose cotransport system.

Cholesterol modulates organic cation transport activity and lipid fluidity in rat renal brush-border membranes

The role of cholesterol in organic cation transport was studied in rat renal brush-border membranes. H+ gradient-dependent uptake of the organic cation tetraethylammonium in brush-border membrane vesicles was stimulated by cholesterol enrichment in a dose-dependent manner. The dissipation rate of the H+ gradient, a driving force for organic cation transport in brush-border membranes, was reduced by cholesterol enrichment. Tetraethylammonium uptake in the absence of H+ gradient was also stimulated by cholesterol enrichment. These findings indicate that cholesterol modulates tetraethylammonium uptake by affecting the intrinsic activity of the organic cation transporter and the H+ gradient dissipation rate. Therefore, cholesterol content should be an important determinant for organic cation transport in renal brush-border membranes.

Gene therapy in Duchenne muscular dystrophy

Experiments in dystrophin gene transgenic mice have supported the concept of treating Duchenne muscular dystrophy (DMD) by demonstrating that regional expression of recombinant dystrophin in dystrophic muscle leads to regional restoration of normal muscle morphology and that dystrophin mini-genes driven by muscle specific regulatory elements are probably more effective than the full-length dystrophin gene. As a gene therapy trial for DMD, dystrophin cDNAs were introduced into skeletal muscle fibers of dystrophin-deficient mice (mdx) through direct DNA injection into plasmid expression vectors, and by replication-defective recombinant retrovirus or adenovirus vectors. With direct injection of dystrophin cDNA into a plasmid expression vector or retrovirus vectors, less than 10% of adult mdx fibers of the injected muscle expressed dystrophin. On the other hand, greater efficiency has been reported for recombinant adenovirus injection into young mdx muscle. However, it is necessary to develop vectors, viral or plasmid DNA, which can be injected intravenously and directed to muscle tissues. This will involve designing vectors possessing appropriate cell-type specific tropism and/or gene transcriptional activity for DMD treatment. This is anticipated to be a vital component in the second stage of experiments aimed at DMD treatment.

Prospective study of the detection of anomalous connections of pancreatobiliary ducts during routine medical examinations

BACKGROUND/AIMS

It is important to achieve detection of of anomalous connections of the pancreatobiliary ducts (ACPBD), because this condition often leads to pancreatobiliary disease. The present prospective investigation focused on revealing the incidence of ACPBD in asymptomatic individuals undergoing medical checkups.

MATERIAL AND METHODS

Extracorporeal ultrasonography (US) was performed on all asymptomatic individuals undergoing medical checkups. Identification by abdominal ultrasonography of 3 mm or more gallbladder wall thickening, or 10 mm or more dilatation of the bile duct were considered indicative of ACPBD and endoscopic ultrasonography (EUS) was carried out in selected cases. Endoscopic retrograde cholangiopancreatography (ERCP) was then performed to confirm the existence of ACPBD.

RESULTS

The overall incidence of ACPBD was 0.03% (9/27,076 subjects). ACPBD was found in 23% of cases with bile duct dilatation, and in 2.9% with gallbladder wall thickening.

CONCLUSION

ACPBD was not as rare a disease as expected. For early detection of ACPBD, identification by abdominal ultrasonography of gallbladder wall thickening or dilatation of the bile duct are indicative. Patients who are suspected of having this abnormality should then undergo EUS. The final diagnosis should then be made by ERCP.

Alzheimer-type pathology in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS)

A 53-year-old Japanese woman with a point mutation in mitochondrial DNA (tRNALeu(UUR), nt3243) consistent with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) and Alzheimer-type brain pathology is reported. This woman had suffered myopathy and psychosis without any clinical evidence of, stroke-like episodes during the last 10 years of her life, and had died after an accident. At autopsy 30 h post mortem, a part of the brain was snap frozen for biochemical and histochemical studies, and the remaining part was processed for a routine examination and electron microscopy. In the brain there were no ischemic lesions. Instead, primitive/diffuse senile plaques were found throughout the brain, predominantly in the frontal and temporal lobes, while Alzheimer neurofibrillary tangles were found only in the parahippocampal gyrus. These plaques were positive for beta-protein and mostly negative for tau protein, ubiquitin, neurofilaments, alpha-choline acetyltransferase, and acetylcholinesterase. Mutations in codon 331 of the ND2 gene as well as codons 693, 713 and 717 of the beta-amyloid precursor protein gene, known to be responsible for some cases of familial Alzheimer disease, were not found. Furthermore, coincidental Down syndrome was ruled out by chromosome analysis. The results suggest a possible correlation between this mitochondrial DNA abnormality and Alzheimer-type pathology.

A newly developed solution enhances thirty-hour preservation in a canine lung transplantation model

Ischemia and reperfusion cause the production of oxygen free radicals. These damage grafts or disrupt normal vascular homeostatic mechanisms, with a parallel reduction in endothelial nitric oxide and adenosine 3',5'-cyclic monophosphate levels. We hypothesized that lung preservation failure may be related to these events. To improve lung preservation, we prepared a new ET-Kyoto solution, which contains N-acetylcysteine (a radical scavenger), nitroglycerin (to elevate the nitric oxide level), and dibutyryl adenosine 3',5'-cyclic monophosphate (to elevate the adenosine 3',5'-cyclic monophosphate level) and examined its efficacy in a canine single-lung transplantation model. Lungs were flushed with new ET-Kyoto solution (group I, n = 9), basal ET-Kyoto solution (group II, n = 6), basal ET-Kyoto solution plus ethanol and propylene glycol (solvents of nitroglycerin; group III, n = 6), or low-potassium dextran glucose solution (group IV, n = 6), and stored at 4 degrees C for 30 hours. After left single-lung transplantation, the right main bronchus and right pulmonary artery were ligated and the functions of the transplanted lung were assessed for 6 hours. Arterial oxygen tension was significantly higher in group I than in groups II, III, and IV (p < 0.05). Peak inspiratory pressure and wet-to-dry lung weight ratio were significantly lower in group I than in groups II and IV (p < 0.01). Histologic and ultrastructural studies showed better preservation in group I than in groups II, III, and IV. We conclude that the new ET-Kyoto solution provides enhanced 30-hour lung preservation.

[Role of apoptosis in the progression of secondary hyperparathyroidism]

In many tissues, cell proliferation is counterbalanced by apoptosis. Hyperparathyroidism is one of the most important complications in long term dialysis patients and is characterized by remarkable cell proliferation of parathyroid cells. Therefore, alteration in the regulation and clearance of excess cells by apoptosis may occur in hyperparathyroidism. In the present study, we evaluated the expression of Ki-67 (proliferative cell associated protein) and Bcl-2(apoptosis-preventing molecules), and the number of apoptotic cells in the nodular lesion of parathyroid glands with secondary hyperparathyroidism(2 degrees HPT), as compared with primary hyperparathyroidism(1 degree HPT) for clarification of the role of apoptosis in the development of 2 degrees HPT. The number of Ki-67+ cells was remarkably increased in 2 degrees HPT(12.02 +/- 10.87, mean +/- SD) compared to in 1 degree HPT(0.81 +/- 0.53) (p < 0.01). However, the number of apoptotic cells was significantly decreased in 2 degrees HPT(0.10 +/- 0.06) compared to in 1 degree HPT(0.31 +/- 0.19) (p < 0.05). To the contrary, Bcl-2+ cells were increased in 2 degrees HPT(0.35 +/- 0.23) compared to in 1 degree HPT(0.10 +/- 0.13) (p < 0.05). These results suggest that the mechanisms of parathyroid cell proliferation are different in each nodular lesion of 1 degree HPT and 2 degrees HPT. Furthermore, the remarkable proliferation of parathyroid glands may have been due to the reduction of the apoptotic process via Bcl-2 expression in 2 degrees HPT.

Time trends and survival after operations for primary lung cancer from 1976 through 1990

To assess the time trends and survivals after operations for primary lung cancer, the cases of 845 consecutive patients who underwent thoracotomy between 1976 and 1990 were retrospectively reviewed by groups corresponding to year of the operation (the early period was 1976 to 1980, n = 208; the middle period was 1981 to 1985, n = 291, and the late period was 1986 to 1990, n = 346). The 5-year survivals at the early, the middle, and the late periods were 31.5%, 39.0%, and 54.0%, respectively, with significant improvement particularly at the late period (p < 0.05 for the early period vs the middle period, p < 0.01 for the early or middle period vs the late period); the improvement was caused by increase in the ratio of patients with stage I disease (20.7% at the early period, 32.0% at the middle period, 44.2% at the late period), increase in the rates of complete tumor resection with lymph node dissection (57.2%, 68.0%, 74.3%, respectively), and decrease in the rates of operation-related death (3.8%, 3.4%, 0.9%, respectively). The postoperative prognosis of patients with stage II disease at the late period (5-year survival 74.8%) showed significant improvement compared with the other periods. Moreover, the prognosis of patients with stage IIIa, pN2 disease (5-year survival 41.5%) showed significant improvement, which was caused by the significant decrease in patients with pT3 N2 M0 disease and poor prognosis.

Regulation of p-aminohippurate transport by protein kinase C in OK kidney epithelial cells

We studied the effect of phorbol 12-myristate 13-acetate (PMA), a phorbol ester which activates protein kinase C, on p-aminohippurate (PAH) transport in OK cells. PMA (10(-7) M) almost completely inhibited the transcellular transport of PAH across OK cell monolayers from the basal to the apical side, as well as the accumulation of PAH in the cells. The uptake of PAH across the basolateral membrane of OK cells was inhibited by PMA in a time-and dose-dependent fashion. Exposing the cells with other protein kinase C activators such as active phorbol esters and diacylglycerols also resulted in a significant inhibition of basolateral PAH uptake, but the inactive phorbol ester, 4 alpha-phorbol 12,13-didecanoate, had no effect. The inhibition of basolateral PAH uptake by PMA was blocked by staurosporine, an inhibitor of protein kinase C. Cycloheximide, actinomycin D, colchicine, and cytochalasin D did not affect the inhibitory effect of PMA on basolateral PAH uptake. These results suggested that the PAH transport system in OK cells is under the regulatory control of protein kinase C.