Biomedical subjects

Makoto Morozumi

Publications and source records attributed to Makoto Morozumi.

9 recordsLinked to original sources

PubMed2003

Milk and calcium prevent gastrointestinal absorption and urinary excretion of oxalate in rats.

Dietary oxalate plays a very important role in the formation of calcium oxalate stones, and dietary intake of calcium may decrease oxalate absorption and its subsequent urinary excretion. The purpose of the present study was to determine the effect on urinary oxalate excretion of an acute oral calcium load, standard milk, or high-calcium low-fat milk followed by a dose of oxalic acid. Male Wistar rats weighing 180-200 g were divided into 7 groups of 6 rats each. All animals were fasted for about 24 hours, anesthetized, and hydrated with normal saline at 3-4 mL/hour. Then the animals were given 1 mL of normal saline [Control], 10 mg (111.1 micromol) of oxalic acid [Ox alone], 2 mL of standard milk (calcium: 1.16 mg or 29 micromol/mL) [NCa milk], 2 mL of high-calcium low-fat milk (calcium: 2.05 mg or 51.3 micromol/mL) [HCa milk], equimolar calcium (4.44 mg or 111 micromol) followed by 10 mg of oxalic acid [Ca + Ox], 2 mL of high-calcium low-fat milk followed by 10 mg of oxalic acid [HCa milk + Ox], or 2 mL of standard milk followed by 10 mg of oxalic acid [NCa milk + Ox]. All treatments were administered via a gastrostomy. Urine samples were collected by bladder puncture just before administration and at hourly intervals up to 5 hours afterwards. Urinary oxalate was measured by capillary electrophoresis, while urinary calcium, magnesium and phosphorus were measured by inductively coupled plasma spectrometry. Urinary oxalate excretion peaked at 1 hour in the Ox alone group, while it peaked at 2 or 3 hours in the Ca + Ox, HCa milk + Ox, and NCa milk + Ox groups. Urinary oxalate excretion decreased significantly when 10 mg of oxalate was administered immediately after the administration of equimolar calcium, high-calcium low-fat milk, or standard milk. The cumulative urinary oxalate excretion over 5 hours was approximately 13.6%, 3.5%, 1.6%, and 2.4% in the Ox alone, Ca + Ox, HCa milk + Ox, and NCa milk + Ox groups, respectively. In conclusions, this study demonstrated that calcium salt, or dairy products containing calcium (especially high-calcium low-fat milk) could decrease the gastrointestinal absorption and subsequent urinary excretion of oxalate.

Animals↗

PubMed2003

Transabdominal vesical sonography of urethral syndrome and stress incontinence.

BACKGROUND: Transabdominal ultrasonography was used to study the bladder neck morphology in women with urethral syndrome or stress urinary incontinence, in order to determine the ultrasonographic findings of these conditions. METHODS: A total of 210 female patients with a normal bladder, asymptomatic trigonitis, urethral syndrome, and stress incontinence were studied. The mucosal thickness around the bladder neck, the length of the anterior base plate of the bladder, and the anteroposterior vesical wall angle (APVA) at the bladder neck were measured on sagittal transabdominal vesical ultrasonograms with the patient in the supine position. RESULTS: Patients with asymptomatic trigonitis or urethral syndrome had thicker mucosa around the bladder neck than the subjects with a normal bladder, and the subjects with stress incontinence had normal mucosa. The APVA was 158 +/- 17 (mean +/- SD) degrees in the subjects with a normal bladder. It was smaller in symptomatic patients and decreased to 109 +/- 10 degrees in those with conservative therapy-resistant incontinence. The anterior edge of the vesical base plate was visible approximately 2 cm from the bladder neck in subjects without incontinence, while it tended to be absent in patients with incontinence and an APVA of less than 126 degrees. CONCLUSION: A small APVA appears to reflect bladder neck descent, while a small APVA without a visible anterior base plate edge may reflect hypotonia of the vesical base plate. Transabdominal vesical ultrasonography with the patient in the supine position provides useful information and can be carried out as a routine examination in female patients with micturition disorders.

Adult↗

PubMed2003

Urinary oxalic acid excretion differs after oral loading of rats with various oxalate salts.

BACKGROUND: To compare urinary oxalate excretion after the oral administration of oxalic acid, disodium oxalate, or calcium oxalate in rats. METHODS: Male Wistar rats were divided into four groups of six rats each and were intravenously hydrated with normal saline, and then were administered normal saline (control group), 10 mg of oxalic acid, equimolar disodium oxalate, or equimolar calcium oxalate via a gastrostomy. Urine specimens were collected just before administration and at hourly intervals up to 5 h afterwards. The urinary oxalate, calcium, magnesium and phosphorus levels were measured. RESULTS: Urinary oxalate excretion peaked at 1-2 h after administration of oxalic acid or equimolar disodium oxalate, while administration of calcium oxalate only caused a small increase of urinary oxalate excretion. Cumulative urinary oxalate excretion during 5 h was 1.69 +/- 0.10 mg (mean +/- SD; 17%), 1.43 +/- 0.13 mg (13%), and 0.22 +/- 0.03 mg (2%) after the administration of oxalic acid, disodium oxalate, and calcium oxalate, respectively. Urinary calcium excretion showed a decrease in the oxalic acid and disodium oxalate groups, while urinary magnesium or phosphorus excretion did not change significantly. CONCLUSION: The upper gastrointestinal tract seems to be the major site of oxalic acid absorption and only free oxalate is absorbed irrespective of whether it is the sodium salt or not. After binding to calcium in the gut, oxalic acid absorption seems to be inhibited in the presence of calcium and this means that calcium oxalate is poorly absorbed (at least in the upper gastrointestinal tract).

Administration, Oral↗

PubMed2003

Urolithiasis in Okinawa, Japan: a relatively high prevalence of uric acid stones.

AIM: The aim of the present study was to investigate the composition of urinary tract stones in patients from Okinawa, the most southern island group of Japan. METHODS: The study was conducted by 12 hospitals in Okinawa. A total of 1816 urinary tract calculi were obtained from 1816 patients (1323 males; 493 females). The patients had a mean age of 53 +/- 15.3 years (mean +/- SD). The calculi were examined to determine their chemical composition. Stone samples were analyzed by computed infrared spectrophotometer. RESULTS: Pure stones comprised 58.4% of the total, with calcium oxalate stones accounting for 40% (21% monohydrate [whewellite]; 6.6% dihydrate [weddellite]; and 12.4% combined monohydrate and dihydrate stones), uric acid/urate stones for 9.6%, calcium phosphate stones for 5.1%, and struvite stones for 3.7%. The other 41.6% of the stones consisted of calcium oxalate mixed with other components. The male-to-female ratio was 2.7:1. CONCLUSION: In our series, calcium oxalate stones accounted for 81.6% of the urinary tract calculi, while uric acid/urate stones accounted for 15.8%. Uric acid stones, predominantly the anhydrous and/or dihydrate forms, showed a relatively high prevalence. Calcium oxalate stones, predominantly in the form of whewellite, showed a high prevalence among pure calculi; while the predominant combinations among mixed calculi were weddellite + calcium phosphate and whewellite + uric acid/urate.

Adolescent↗

PubMed2003

Hepatic alanine-glyoxylate aminotransferase activity and oxalate metabolism in vitamin B6 deficient rats.

PURPOSE: Urinary oxalate has an important role in the formation of calcium oxalate stone and approximately 50% to 60% of urinary oxalate is derived from the endogenous metabolism of glyoxylate. Glyoxylate is enzymatically converted to glycine by alanine-glyoxylate aminotransferase in the liver and vitamin B6 has a key role as a coenzyme. Therefore, we evaluated hepatic alanine-glyoxylate aminotransferase activity and oxalate metabolism in vitamin B6 deficient rats. MATERIALS AND METHODS: A total of 12 male Wistar rats were fed a control or a vitamin B6 deficient diet. After 4 weeks creatinine, oxalate, glycolate, glycine and citrate in the urine, and alanine-glyoxylate aminotransferase activity and its mRNA level in the liver were measured. RESULTS: Urinary oxalate-to-creatinine and glycolate-to-creatinine ratios were significantly higher in vitamin B6 deficient rats than in control rats but urinary glycine-to-creatinine and citrate-to-creatinine ratios were significantly lower. Hepatic alanine-glyoxylate aminotransferase activity and its mRNA level were significantly lower in vitamin B6 deficient rats than in control rats. CONCLUSIONS: Vitamin B6 deficiency not only decreased alanine-glyoxylate aminotransferase activity, but also down-regulated alanine-glyoxylate aminotransferase gene expression by hepatocytes and led to hyperoxaluria and hyperglycolic aciduria secondary to impaired metabolism of oxalate precursors. Hyperoxaluria with hypocitruria may also contribute to calcium oxalate stone formation in vitamin B6 deficiency.

Animals↗

PubMed2002

Capillary electrophoresis assay of alanine:glyoxylate aminotransferase activity in rat liver.

We measured hepatic alanine:glyoxylate aminotransferase (AGT) activity using capillary electrophoresis. After rat liver homogenate was incubated in the presence of substrates and pyridoxal 5'-phosphate, the pyruvate and glycine produced by AGT were measured. The AGT activity was 10.02+/-0.31 micro mol pyruvate/h/mg protein and 10.21+/-0.15 micro mol glycine/h/mg protein. This method is relatively simple and shows superior sensitivity, allowing the measurement of enzyme activity in 5 micro g of protein. Therefore, it appears to be suitable for laboratory use and may also have advantages for measuring AGT activity in liver biopsy specimens.

Animals↗

PubMed2002

Ultrasonographic changes of the female bladder neck during development.

BACKGROUND: Our previous study showed that the anteroposterior vesical wall angle (APVA) at the bladder neck on transabdominal ultrasonography varied widely between women. The present study examines whether the APVA changes during development in girls with a normal bladder. METHODS: Seventy-four females aged 0-29 years with normal bladders were examined by transabdominal ultrasonography. They were divided into six age groups and their APVA was measured in the supine position by sagittal ultrasonography. Intravenous urography was conducted to examine bladder neck descent and bladder neck opening. RESULTS: The APVA ranged from 85 to 200 degrees. The mean APVA in girls aged 0-4 years was 129 +/- 30 degrees (+/-SD) and the mean APVA in girls aged 5-9 years was 135 +/- 25 degrees. The mean APVA at ages 10-14 years was 161 +/- 26 degrees; at 15-19 years, 164 +/- 33 degrees; at 20-24 years, 164 +/- 18 degrees; and at 25-29 years, 163 +/- 16 degrees. The APVA values of these four groups were significantly larger (P < 0.05) than those of the two younger groups. No bladder abnormalities were found on intravenous urography. CONCLUSION: The APVA was small in some girls under 10 years of age, but the APVA of girls aged over 10 years was similar to that in young adults. The APVA may reflect bladder base plate tone and be partially related to hormonal changes in females during development.

Adolescent↗

PubMed2002

Partial nephrectomy using a vascular sealing system.

PURPOSE: The margin resected at partial nephrectomy is so fragile that it is not easy to control bleeding. To control bleeding we developed a new technique using a vascular sealing system for hemostasis. MATERIALS AND METHODS: A 38-year-old woman with renal cell carcinoma underwent partial nephrectomy. A tumor was identified in the lower pole of the left kidney. The kidney was exposed with the perinephric fat and the main renal artery was identified and clamped. Along the incision line the renal cortex was cut sharply to 10 to 15 mm. deep. A jaw of the vascular sealing system was carefully inserted into the sinus space between the renal pelvis and medulla. The jaws were gradually clamped together, and the renal medulla and vasculature were compressed and then sealed completely by computer controlled current. Because the renal pelvis was involved by tumor, the pelvis was removed partially with the tumor and approximated with absorbable sutures. RESULTS: Before reperfusion only a few additional sutures were needed for hemostasis. Warm ischemia time was 19 minutes. CONCLUSIONS: Our technique seems to be a promising method of rapidly achieving reliable hemostasis for partial nephrectomy.

Adult↗

PubMed2002

Association of vitamin D receptor gene polymorphism with urolithiasis.

PURPOSE: Recent studies suggest that allelic variations of the vitamin D receptor (VDR) gene can influence calcium absorption and excretion. Therefore, we studied the association of VDR gene polymorphism with urolithiasis. SUBJECTS AND METHODS: We studied 83 patients with urinary stones and 83 controls. Patients were scored for certain clinical characteristics, including long axis diameter of the largest stone (1 point-less than 10 mm. and 2-10 mm. or greater), number of stones (1 point-1 and 2-multiple) and history of calcium stone disease (1 point-absent and 2-present). They were classified into 3 groups according to the total score, including low-3, intermediate-4 or 5 and high-6 points. The 2 VDR gene polymorphisms TaqI and ApaI were detected by polymerase chain reaction-restriction fragment length polymorphism and their relationships with the urinary calcium level were examined. RESULTS: The incidence of TaqI Tt and tt genotypes was significantly higher in the high score group than in controls. The TaqI t allele was associated with a 5.2-fold increase in the risk of severe stone disease. The urinary calcium level in patients with the Tt and tt genotypes was also higher than in those with the TT genotype. The rate of the ApaI genotype was not different in the high score group and controls. CONCLUSIONS: The TaqI t allele of the VDR gene may be a risk factor for severe stone disease and recurrent stones.

Adult↗