Narumi Taniguchi

A Study Of Micturition Inducing Sites In The Periaqueductal Gray Of The Mesencephalon

PURPOSE The mesencephalon, especially the periaqueductal gray, is believed to integrate specific movement patterns of the somatic and autonomic nervous system, including those of vocalization, defensive behaviors and others. Fiber communications exist between the periaqueductal gray and the pontine micturition center, and many nerve fibers ascending from the sacral spinal cord project to the periaqueductal gray. We examined whether the mesencephalon is involved in micturition function using microstimulation and a neurotracer. MATERIALS AND METHODS We decerebrated 28 adult cats under general anesthesia. An electrode that can be used for microinjection was positioned in stereotaxic fashion in the mesencephalon and pons. Subsequently electrical stimulation and chemical stimulation with DL-homocysteine acid were applied to search for micturition inducing sites. Blood pressure and respiration were monitored simultaneously. We also performed electrical microstimulation of pontine micturition center. The neurotracer 5% Fluoro-Gold (Denver, Colorado) was injected into these sites to identify neural pathways between the mesencephalon and pons. The brainstem was removed after 10 hours and the mesencephalon was examined by fluorescence microscopy. RESULTS Bladder contraction was provoked by electrical and chemical stimulation applied mainly at the ventrolateral side of the periaqueductal gray. Blood pressure increased simultaneously with bladder contraction after periaqueductal gray stimulation. Neurotracer injected into the pontine micturition center was found mainly on the ventrolateral side of the periaqueductal gray, in agreement with the sites where micturition was provoked by microstimulation. CONCLUSIONS Nerve cells on the ventrolateral side of the periaqueductal gray have neural communications with the pontine micturition center bilaterally and they regulate micturition.

Micturition-suppressing region in the periaqueductal gray of the mesencephalon of the cat

The periaqueductal gray (PAG) of the mesencephalon has been implicated to be involved in the control of micturition. We investigated the micturition-suppressing region in the PAG of the cat. Decerebrated 27 adult cats were used. A microelectrode was inserted stereotaxically into the PAG, and a region was searched where electrical stimulation suppressed isovolumetric bladder contractions. Simultaneous stimulation of the pontine micturition center (PMC) and micturition-suppressing region in the PAG was performed before and after an injection of bicuculline (GABA(A) blocker) into the PMC. The micturition-suppressing region was found at the dorsolateral margin of the rostral PAG. Bladder contractions were not provoked by simultaneous stimulation of the PMC and micturition-suppressing region in the PAG. However, after bicuculline injection into the PMC, partial bladder contractions were provoked by simultaneous stimulation of the PMC and the micturition-suppressing region in the PAG. These results suggest that the dorsolateral margin of the rostral PAG includes the micturition-suppressing region that seems to have neural connections with the PMC. GABA is assumed to be one of the neurotransmitters that are involved in the PMC inhibition from the micturition-suppressing region in the PAG.

Leiomyoblastoma of the epididymis in a child

A case of leiomyoblastoma of the epididymis in a 3-year-old boy is presented. Left high inguinal orchiectomy was performed. Light and electron microscopic examinations revealed a 3.5 X 2.3 X 1.5 cm. tumor continuous with the tail of the epididymis. The lesion proved to be a leiomyoblastoma of the epididymis. Leiomyoblastoma is a form of leiomyoma mainly composed of immature smooth muscle cells. The absence of keratin, epithelial membrane antigen and negative results by alcian blue stain indicated that there were no adenomatoid elements in the tumor.

Three cases of urolithiasis associated with sarcoidosis: A review of Japanese cases

Abstract:  We report three cases of urolithiasis associated with sarcoidosis and reviewed the Japanese published reports. All cases had hypercalcemia, hyperuricemia, hypercalciuria and renal dysfunction. A serum level of 1,25‐(OH)2D3 was elevated and intact parathyroid hormone (PTH) was decreased. Stone components were predominantly calcium oxalate. Abnormal calcium metabolism is a well‐known feature of sarcoidosis and the reported prevalence of urolithiasis in patients with sarcoidosis was 1.3–14.0% in the English published reports. However, urolithiasis associated with sarcoidosis is uncommon in Japan and we could find only 16 documented cases including ours. Abnormal calcium metabolism is caused by an increase in serum concentration of 1,25‐(OH)2D3, which is derived from endogenous overproduction in the pulmonary macrophages. If patients with urolithiasis have abnormal calcium metabolism, renal impairment and suppression of PTH, the possibility of sarcoidosis should be considered for a differential diagnosis. Also, it should be emphasized that the presence or developing of urolithiasis is to be monitored during follow up of patients with sarcoidosis.

NEUROPATHIC BLADDER DYSFUNCTION IN PATIENTS WITH OSSIFICATION OF THE POSTERIOR LONGITUDINAL LIGAMENT

Background: Ossification of the posterior longitudinal ligament (OPLL) may cause neuropathic bladder dysfunction due to spinal cord involvement. OPLL, unlike a traumatic spinal cord lesion, progresses insidiously and sometimes affects longer cord segments. As the manifestation of bladder dysfunction may depend on the development of OPLL, we studied the relationship between bladder function and roentgenographic changes in the spinal canals of OPLL patients.