Masami Oda

EVIDENCE FOR INVOLVEMENT OF THE SUBCOERULEUS NUCLEUS AND NUCLEUS RAPHE MAGNUS IN URINE STORAGE AND PENILE ERECTION IN DECEREBRATE RATS

PURPOSE Micturition and male sexual activity require the lower urinary tract to function. During the sexual act, micturition must be inhibited and urine stored in the bladder. We studied the role of the brainstem in relation to both micturition/urine storage and penile erection in rats. MATERIALS AND METHODS Wire electrodes were placed on the dorsal nerve of the penis and microelectrodes for stimulation were introduced into the brainstem in decerebrate male rats. Electrical stimulation was used to locate optimally responding sites by monitoring the isovolumetric intravesical pressure and intracavernous pressure. RESULTS Electrical stimulation of the dorsal nerve of the penis, the subcoeruleus nucleus in the rostral pons, and the nucleus raphe magnus in the caudal pons increased intracavernous pressure, but inhibited rhythmic bladder contractions. Electrical stimulation of Barringtons nucleus (the pontine micturition center in the rat) in the rostral pons induced bladder contraction. Stimulation of the pontine reticular formation did not increase intracavernous pressure. Acute transection of the thoracic spinal cord eliminated rhythmic bladder contractions, but gave rise to sporadic increments of intracavernous pressure. CONCLUSIONS This electrophysiological study demonstrated that the subcoeruleus nucleus and nucleus raphe magnus are involved in both urine storage and penile erection, and that their physiological functions are reciprocally controlled; so that erection leads to inhibition of micturition.

URINARY SATURATION AND RISK FACTORS FOR CALCIUM OXALATE STONE DISEASE BASED ON SPOT AND 24-HOUR URINE SPECIMENS

In 222 random spot urine specimens, the calcium concentration and calcium oxalate saturation [DG(CaOx)] were significantly higher among stone formers than among non-stone formers, while the citrate and creatinine-corrected citrate concentrations were lower. In 188 24-hour urine specimens, magnesium excretion was lower among stone formers than non-stone formers, while the creatinine-corrected calcium concentration and DG(CaOx) were higher. Among stone formers, there was no gender difference in the urinary concentrations of calcium, oxalate, citrate, magnesium, and DG(CaOx), but the creatinine-corrected calcium, citrate, and magnesium concentrations were higher in women, as well as 24-hour citrate excretion. The levels of calcium and oxalate have a major influence on DG(CaOx), while citrate and magnesium levels have a minor influence. DG(CaOx) was correlated with calcium and oxalate excretion, as well as with the creatinine-corrected calcium and oxalate concentrations. Approximately 5% of 24-hour urine specimens showed critical supersaturation, 80% showed metastable supersaturation, and 15% were unsaturated. Hypercalciuria or hyperoxaluria was fairly common (30% and 40%) in critically supersaturated urine, while it was less common (22.4% and 8.6%) in metastably supersaturated urine and was not detected in unsaturated urine. Hypocitraturia and/or hypomagnesiuria was more common (63.8-80%) at any saturation. The urinary calcium, oxalate, and citrate concentrations, as well as the creatinine-corrected calcium, oxalate, citrate, and magnesium concentrations and DG(CaOx), showed a significant correlation between 57 paired early morning spot urine and 24-hour urine specimens. The creatinine-corrected calcium and citrate concentrations of the early morning urine specimens were significantly correlated with the levels of calcium and citrate excretion in the paired 24-hour urine specimens. In conclusion, no parameter other than urinary saturation gives more than a vague indication of the risk of lithogenesis, so DG(CaOx) in either early morning urine or 24-hour urine specimens appears to be the best predictor of stone risk. Finally, the creatinine-corrected calcium and citrate concentrations in early morning urine can be used as a substitute for measuring 24-hour excretion.

Major factors modulating the serum oxalic acid level in hemodialysis patients.

Ascorbic acid overload and vitamin B6 deficiency have been implicated in the development of hyperoxalemia in dialysis patients, but there is still disagreement about this. Hemodialysis patients who are exposed long-term hyperoxalemia may develop secondary oxalosis with an increased risk of cardiac, vascular, and bone disease, and thus may benefit from maintaining a low serum oxalic acid level. In 452 hemodialysis patients, the serum level of oxalic acid was 47.2 +/- 22.9 micromol /l before and 16.9 +/- 10.5 micromol/l after a 4-hour dialysis session, while the ascorbic acid levels were 39.0 +/- 92.7 micromol/l and 6.5 +/- 18.6 micromol/l, the glycolic acid levels were 7.3 +/- 10.1 micromol/l and 0.6 +/- 2.3 micromol/l, and the citric acid levels were 141.3 +/- 54.7 micromol/l and 117.6 +/- 37.2 micromol/l, respectively. Most patients (65.3 percent) had low serum ascorbic acid levels (less than 10 micromol/l) before hemodialysis. The serum level of oxalic acid [Ox] showed a significant positive correlation with the levels of ascorbic acid [AA], glycolic acid [Gly], and creatinine [Cre]: [Ox] = 21.711 + 0.181 x [AA] + 0.174 x [Gly] + 0.171 x [Cre], (all micromol/l, p less than 0.05). In 124 dialysis patients, the 4-pyridoxic acid level was 8.9 +/- 19.6 micromol /l before and 3.9 +/- 8.8 micromol/l after dialysis, and it was not correlated with oxalic acid or glycolic acid. Most dialysis patients (65.3 percent) had low serum levels of ascorbic acid, but a subgroup of patients (12 percent) had high serum ascorbic acid levels (more than 100 micromol/l) associated with hyperoxalemia (88.2 +/- 24.5 micromol/l). High-dose vitamin C supplementation may aggravate hyperoxalemia in hemodialysis patients, so attention should be paid to avoiding this risk.

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.

Prognosis of bedridden patients with end-stage renal failure after starting hemodialysis

BackgroundThe mean age of starting hemodialysis (HD) in patients with end-stage renal failure is gradually increasing in Japan. It is not uncommon for HD to be commenced in bedridden elderly patients who cannot give informed consent, because of brain damage. However, we have not been able to provide useful advice to their families because there was no relevant information available about the prognosis of bedridden patients on HD. Therefore, we examined the prognosis of bedridden HD patients.MethodsTwo hundred and nineteen patients who received HD were enrolled. These subjects were divided into five groups; (aged <50, 50–59, 60–69, 70–79, and ≥80 years at the commencement of HD), and we compared the overall prognosis between bedridden and nonbedridden patients, as well as that for each age group.ResultsThere were 76 bedridden patients among the 219 HD patients, and the main cause of their bedridden state before starting HD was cerebrovascular disease. The 50% survival time after the start of HD was 120 months for the nonbedridden patients versus 56 months for bedridden patients. However, the mean (±SD) age of the bedridden patients was higher than that of nonbedridden patients (70 ± 13 versus 64 ± 14 years). In patients under age 50 years at the start of dialysis, the survival rate was lower in the bedridden than in the nonbedridden patients, but there were no differences between survival rates for bedridden and nonbedridden patients in the other four age groups.ConclusionsThe prognosis of HD patients is poor compared with the general life expectancy of the Japanese population, but whether these patients are bedridden or not has little influence on their survival.

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.

Effect of Injury to the Dorsal Funiculus of the Thoracic Spinal Cord on Micturition in Decerebrate and Freely-Moving Cats

Bladder sensation is transmitted both via the spinothalamic tract in the lateral funiculus and the dorsal system in the dorsal funiculus. We transected the dorsal funiculus in 10 female cats to clarify the functional roles of these two ascending pathways. The dorsal funiculus was transected at T10 in 5 decerebrate and 5 freely-moving cats, and micturition parameters were compared before and after transection. Transection of the dorsal funiculus did not affect any of the parameters of reflex micturition in the 5 decerebrate cats. Within 1 week after transection, 4 of the 5 freely-moving cats used the normal micturition posture, but the remaining one performed micturition in a prone position as if she had lost micturition sensation. All 5 cats urinated with a normal micturition posture by 2 weeks after transection. The mean single voided volume was decreased transiently up to 1 week, but returned to normal by 2 weeks after transection. None of the 5 cats had any residual urine before and after transection. Both the ascending and descending limbs of the micturition reflex pass through the lateral funiculus. Bladder sensation is transmitted both via the spinothalamic tract coursing in the lateral funiculus and the dorsal system in the dorsal funiculus. The dorsal system may play a major role in the transmission of bladder sensation to the cerebral cortex, but may not be essential.

New 3-Dimensional Mapping Device for Cystoscopy

PURPOSE The crucial shortcoming of cystoscopy is that it does not measure the size of observed objects, and so we developed a new device that adds measurement capability to the cystoscope. MATERIALS AND METHODS The device consists of 5 arms linked to each other by freely bending joints. Before use 1 end of the arm is fixed to the examination table and the other end is linked to the eyepiece of the cystoscope. While linked to the arms, the cystoscope can move freely in any direction. Each joint carries an accurate sensor to measure its angle. The angle measurements are calculated collectively to obtain the 3-dimensional coordinates at the tip of the cystoscope. The tip of the cystoscope can be moved to the other side of the objects to be measured, which provides a pair of 3-dimensional coordinates, because the distance between them can be calculated. RESULTS We could calculate the distance between the bladder neck and each ureteral orifice, and the angle of the bladder neck formed with the left and right orifices in clinical cases. By continuous measurement of the location of the bladder neck and the ureteral orifice, it was clearly demonstrated that the distance between them increased as the bladder filled. CONCLUSIONS Our computer assisted, 3-dimensional mapping device can replace unreliable cystoscopic assessment with more reliable numerical values. New diagnostic criteria based on the exact numerical values can be established with the use of this device.

Exact Documentation of Location and Size of Bladder Tumor with a Three–Dimensional Mapping Device

Background Cystoscopy is one of the most important devices for diagnosing bladder tumor, but has a crucial shortcoming—the size of observed objects cannot be measured. This paper describes a new method to measure the position and size of a bladder tumor using a three–dimensional mapping device.

Cytokine production by peripheral blood lymphocytes and their LAK cell activity in patients on short- or long-term hemodialysis.

透析患者の末梢血リンパ球 (PBL) 機能について検討した. 対象は透析開始3年以内の透析導入および透析安定群, 10年以上の長期透析群, そして腎機能正常な対照群である. 検討項目は, PBLまたはLymphokine-activated killer (LAK) 細胞によるサイトカイン (IFN-γとTNF-α) 産生能と, 末梢血モノサイトのInterleukin-1 (IL-1) 産生能, そしてLAK細胞活性である. 透析開始3年以内の群では, 対照群に比して, LAK活性とIL-1産生能が有意に低下し, LAK細胞によるIFN-γ産生能も低下傾向を示した. Interleukin-2 (IL-2) 刺激PBLのIFN-γおよびTNF-αの産生量に関しては症例によりバラツキが大きく, 透析患者の両群いずれにおいても, 対照群との間に有意な差は見られなかった. 両サイトカインのともに産生量の低下した症例の割合が対照群に比べ3年以内の群で多かったが, 統計学的には有意な差は認められなかった. 一方TNFとIFNの産生量の多寡に関して相関が認められた. 従ってIL-2刺激により誘導されるLAK活性が低下している等の結果から, 透析3年以内の群において, IL-2に対するPBLの反応性の低下した症例の存在が示唆された.以上より, 我々の測定した免疫のパラメータに関するかぎり, 透析導入3年以内の患者においては免疫能の低下が認められるが, 10年以上の長期透析患者の免疫能は改善し, 健腎対象群のそれとに差異が認められなかった.