Using a grating structure for phase compensation in achieving an efficient round-trip optical parametric process in periodically poled lithium niobate with an incomplete quasi-phase-matching period

An incomplete period of the last quasi-phase-matching (QPM) segment in a periodically poled nonlinear crystal represents a key problem in implementing a nonlinear wavelength-conversion device with round-trip or oscillating waves of interaction. Such a segment at the crystal end implies broken QPM periodicity for the reflected waves of interaction. We demonstrate numerically that with a grating structure at the crystal end for the reflecting signal the wavelength-dependent phase shift at Bragg reflection can compensate for the phase mismatch of the reflected signal, idler, and pump of an optical parametric process. Therefore, by slightly shifting the signal wavelength we can maintain the phase-matching condition with any length of the last QPM segment. It is shown that with a grating structure the conversion efficiency of the round-trip optical parametric process can always be optimized.

Iatrogenic abdominal scar endometriosis: a case report

We report the case of a patient with abdominal scar endometriosis following a cesarean section. The rarity of this localization and its appearance on computerized tomography is shown. We emphasize the combination of history and image study of this pathology in the differential diagnosis of other diseases.

Cervical cord tethering mimicking focal muscular atrophy

Spinal cord tethering rarely occurs in the cervical region. In adults, it usually results from previous operations. However, congenital origin is always diagnosed and treated early in the infant period. We report a 12-year-old boy with cervical spinal dysraphism which was erroneously diagnosed as focal muscular atrophy, a benign form of motor neuron disease. The patient was brought to our hospital because of rapid deterioration of symptoms. Careful evaluation disclosed a hairy dimple at the nuchal area, which led to the correct diagnosis. X-ray of the cervical spine showed spina bifida from C(4) to C(6) levels and fusion of the laminae of C(4) and C(5). Spine MRI studies disclosed that the cervical cord was tethered caudally and dorsally, and the ventral nerve roots were markedly stretched, especially over the left side. Surgical intervention was undertaken and the patient's muscle power improved after untethering. The purpose of this report is to acquaint the reader with a surgically treatable condition that may appear to be benign focal amyotrophy. Skin lesion at the nuchal area should be carefully looked for.

Management of pancreatic pseudocysts by endoscopic cystogastrostomy

Open surgical drainage is currently the treatment of choice for pancreatic pseudocysts, but endoscopic transmural drainage is another minimally invasive surgical alternative. In this report, we describe two patients with symptomatic pancreatic pseudocysts treated with endoscopic cystogastrostomy. The first patient, a 15-year-old boy, had an episode of traumatic pancreatitis after abdominal injury from a car accident, and complained of postprandial vomiting and abdominal distention 4 weeks later. A large pancreatic pseudocyst, about 10 cm x 6 cm, was noted. The second patient, a 44-year-old man, had a 1-year history of recurrent alcoholic pancreatitis prior to this admission. He suffered from abdominal distention for several weeks. Sonography revealed a large pancreatic pseudocyst, about 18 cm x 9 cm in size. Both patients underwent successful endoscopic cyst-drainage without recurrence. These cases illustrate that endoscopic transmural drainage provides a minimally invasive and effective approach to the management of pancreatic pseudocysts.

Assessment of cardiac sympathetic regulation by respiratory-related arterial pressure variability in the rat

1. Mechanical ventilation evokes a corresponding arterial pressure variability (APV) which is decreased by beta-adrenoceptor antagonism. Therefore, in this study we set out to determine whether the respiratory-related APV can be used to assess cardiac sympathetic tone. 2. Computer-generated broad-band mechanical ventilation (0-3 Hz) was applied to Sprague-Dawley rats that had been anaesthetized with ketamine and paralysed with pancuronium. APV and its relationship to lung volume variability (LVV-APV) was systematically quantified with auto- or cross-spectral frequency domain analysis. 3. APV and LVV-APV transfer magnitudes between 0.5 and 1.5 Hz showed dose-dependent suppression by propranolol from 0.01 to 1 mg kg-1, while the static value of arterial pressure remained unchanged. Stroke volume variability, assessed by the use of a pulse contour method, exhibited a similar pattern of suppression by propranolol. In contrast, heart rate variability was not lowered with propranolol. 4. The effect of propranolol on respiratory-related APV persisted even in the presence of combined alpha-adrenoceptor and muscarinic receptor blockade by phentolamine and atropine. 5. The frequency range of 0.5-1.0 Hz was optimal for LVV-APV transfer magnitude to correlate with cardiac sympathetic tone. 6. We conclude that respiratory-related APV may provide a valid assessment of cardiac sympathetic regulation which is independent of parasympathetic and vascular sympathetic influences in ketamine-anaesthetized and positive pressure-ventilated rats.

Screening cystoscopy in chronically catheterized spinal cord injury patients

STUDY DESIGN

Retrospective review.

OBJECTIVES

An annual screening cystoscopy protocol was begun at our institution in an attempt to minimize the morbidity and mortality of bladder cancer in the chronically catheterized spinal cord injured (SCI) population. The objectives of this study are: (1) to present the results of 6 years of screening for primary bladder cancer in this population, and (2) examine the suitability of this protocol based upon accepted principles of cancer screening.

SETTING

Veterans hospital, Seattle, WA, USA.

METHODS

SCI patients selected for screening cystoscopy were those who had been continuously catheterized for 10 or more years, or were smokers who had been catheterized for 5 or more years. Biopsies and/or urine cytologies were taken at the surgeon's discretion.

RESULTS

Fifty-nine patients underwent 156 cystoscopy procedures from January 1992 through December 1997. The vast majority of patients were at risk for autonomic dysreflexia, so cystoscopy was performed with anesthesia. No bladder cancers were diagnosed by screening cystoscopy. All bladder biopsies and cytology specimens were benign. During the same period of time four SCI patients presented with symptomatic bladder cancers. Two patients did not fit the criteria for surveillance, one patient was not being followed by the SCI unit and presented to an outside physician, and one patient had a screening cystoscopy 4 months prior to presenting with bladder cancer.

CONCLUSIONS

Cystoscopy does not fulfil the accepted criteria for screening for primary bladder cancer in SCI patients. The disease does not appear to be amenable to screening, the population to be screened is not easily definable, and the costs are excessive compared to the low cancer detection rate.

Somatic innervation of the human bulbocavernosus muscle

OBJECTIVE

To demonstrate the somatic reflex innervation of the bulbocavernosus muscle (BCM), the principal muscle for ejaculation.

METHODS

Genitourinary electrodiagnostic testing utilizing modifications of the standard bulbocavernosus reflex was performed in 13 healthy male volunteers ages 20-43.

RESULTS

Bulbocavernosus muscle contraction was elicited by stimulation of the dorsal nerve of the penis, from both the penile skin and from the anterior urethra, and following stimulation of the perineal nerve. Latencies were variable depending on the point of stimulation.

CONCLUSIONS

All 3 afferent pathways synapse on pudendal motoneurons in the conus medullaris, and provide for peripheral reflex control of BCM contractions. Based on the latencies of the urethral evoked responses, urethral innervation differs from penile shaft innervation, each having a distinct population of the dorsal nerve of the penis (DNP) fibers. The presence of an electrically-defined pathway from the anterior urethra to the BCM suggests that somatic afferents from the anterior urethra are involved with the ejaculatory reflex. These somatic reflexes are components of normal ejaculatory function. The findings contribute to understanding the neurophysiology of ejaculation, and may be applicable to the evaluation of ejaculatory disorders.

A comparison of 3-D data correlation methods for fractionated stereotactic radiotherapy

PURPOSE

Stereotactic radiosurgery is currently used to treat patients who are not good candidates for conventional neurosurgical procedures. For treatments of nonvascular tumor cells, it appears that fractionation offers a radiobiological advantage between tumor and normal tissues. Therefore, fractionated stereotactic radiotherapy (FSR) is preferred because it minimizes normal tissue complications and maximizes local tumor control probability. We have implemented a methodology clinically to perform the noninvasive patient repositioning technique. The 3-D data correlation method for high-precision and multiple fraction stereotactic treatments has been presented.

METHODS AND MATERIALS

Three different optimization algorithms (Hooke and Jeeves optimization, simplex optimization, and simulated annealing optimization) are evaluated to calculate the transformation parameters necessary for FSR. A least-square object function is created to perform the 3-D data matching process. By minimizing the unconstrained object function value the best fit can be approached for the reference 3-D data sets. Simulation shows that these algorithms deliver results that are comparable to the previously published correlation algorithm (1,2) (singular value decomposition [SVD] method). The advantage for optimization algorithms is easily understood and can be readily implemented by using a personal computer (PC). The mathematical framework provides a tool to calculate the transformation matrix which can be used to adjust patient position for fractionated treatments. Therefore, using these algorithms for a high-precision fractionated treatment is possible without an invasive repeat fixation device and has been implemented clinically. A bite plate system was incorporated to acquire 3-D patient data. With a 3-D digital camera localization device, the patient motion can be followed in real time with the system calibrated to the isocenter.

RESULTS

Two types of data sets are utilized to study the correlation results. One is using the digitized patient data which were retrieved clinically. The other is using the randomly generated data sets. Simulation errors for the optimization algorithms are all less than 1 mm in translation and less than 1 degree in rotation. Currently, FSR is performed using special designed repeat fixation devices which assure reproducible patient position for multiple fractions of radiation treatment. Clinical results indicated that this technique provided excellent treatment results.

CONCLUSION

Three optimization algorithms have been applied and evaluated in calculating the transformation parameters between two 3-D contours or digitized data points. The mathematical functions behind these optimization algorithms are straightforward and can be easily implemented. When incorporated with the proper CT/MR image data with an electronic portal imaging (EPI) system, this process can possibly verify the patient's treatment position whenever there is doubt about the movement during the treatment procedure.

Bilateral gluteal dystrophic calcification--a case report

Abnormal deposits of calcium in the injured and necrotic tissue (dystrophic calcification) are not considered to be rare conditions in human pathologic records. We report a severe case of bilateral gluteal calcification that has not often been found in the literature. It was caused by multiple intramuscular and/or subcutaneous injections. The multiple lumps along with the chronic unhealed fistula over the gluteal regions were successfully treated by carbon dioxide laser without recurrence. The pathogenesis of variable possibilities were reviewed and discussed.

Innervation of the human glans penis

PURPOSE

We demonstrate the innervation of the glans penis through nerve blockade and electrophysiological tests.

MATERIALS AND METHODS

The study was conducted in 14 healthy, sexually potent volunteers. The dorsal nerves of the penis were anesthetized bilaterally with lidocaine. Electrophysiological testing was performed by stimulating the dorsal nerve of the penis at the penile base distal to the block and recording action potentials at the glans.

RESULTS

Dorsal nerve of the penis block resulted in anesthesia of the dorsal, lateral and glanular aspects of the penis. The ventral surface, including the frenulum, was intact to pinprick sensation. Dorsal nerve of the penis stimulation resulted in responses from the corona, dorsal and ventral mid glans, and penile shaft. Frenular responses were less consistently obtained. The most common recorded pattern was a monophasic waveform representing the arrival of a standing potential at a nerve terminal. Latencies were progressively longer with increasing distance from the point of stimulation with the longest latencies measured at the frenulum. Amplitudes of the responses decreased with increasing distance from the point of stimulation.

CONCLUSIONS

The dorsal nerve of the penis innervates the glans, including the frenulum which is also innervated by a branch of the perineal nerve. Branches of the dorsal nerve of the penis extend through the glans ventrolaterally. Electrical representation of glanular innervation reveals the glans to be filled with nerve endings supporting its function as a sensory structure.

The clinical significance of hyperamylasemia in organophosphate poisoning

OBJECTIVE

Hyperamylasemia with a presumptive diagnosis of acute pancreatitis has been reported following organophosphate poisoning but there are no large-scale studies incorporating more specific diagnostic criteria.

METHODS

Retrospective review of the medical records of 159 patients with a diagnosis of organophosphate poisoning over 3 years. Serum amylase, pancreatic amylase, salivary amylase, lipase and cholinesterase levels, and the clinical manifestations were analyzed.

RESULTS

Serum amylase data was available for 121 of the 159 study patients. Hyperamylasemia (amylase > or = 360 U/L) was found in 44 patients (36%). Lipase was measured in 28 patients with hyperamylasemia; 9 of 28 had hyperlipasemia (lipase > or = 380 U/L). The finding of hyperamylasemia was closely related to clinical severity and presence of shock. A presumptive diagnosis of painless acute pancreatitis was diagnosed by hyperlipasemia associated with hyperamylasemia, clinical severity, serum LDH, and leukocyte counts. Two patients with presumptive pancreatitis died. Shock, coma, and hypoalbuminemia were the factors predicting fatality.

CONCLUSIONS

Hyperamylasemia is frequent in severe organophosphate poisoning. However, hyperamylasemia is not synonymous with acute pancreatitis and pancreatic amylase is not a reliable parameter in the diagnosis of organophosphate-induced pancreatitis due to its low sensitivity and specificity. Lipase assay is indicated in patients with hyperamylasemia for early diagnosis of pancreatitis. Proper image studies and even pathological examination are also needed to confirm the extent of pancreatic injury. With prompt diagnosis and appropriate treatment, a complete recovery can be anticipated unless the patient has otherwise unrelated complications.

Concentrated cresol intoxication

Cresol, a commonly used disinfectant, may cause gastrointestinal corrosive injury, central nervous system and cardiovascular disturbances, and renal and hepatic injury following intoxication. We report a case of acute severe cresol poisoning after a suicide attempt with ingestion of a cresol-soap solution used as a toilet disinfectant. A 44-y-old male was found unconscious after ingesting 300 ml of 50% cresol-soap solution. Endotracheal intubation, gastric lavage and activated charcoal were given immediately which reversed his conscious. He had dermal burns, esophageal and gastric erosion, pneumonia, mixed metabolic acidosis and respiratory aklalosis, renal and liver function impairment, leucocytosis and dark urine. Acute renal failure and hemolysis developed, but he recovered after hemodialysis and intensive supportive care. Urine levels of p-cresol, m-cresol, o-cresol and phenol were respectively 2083, 2059, 125 and 68 mg/g creatinine at 7 h post-ingestion. Though the amount cresol claimed ingested by the patient (150 g) far exceeded the reported lethal dose (30-60 g), and multiple complications developed after massive ingestion, this patient recovered. The renal, pulmonary and hematological effects in this patient might have resulted from the direct toxicity of cresol and its metabolites.

A case of severe hyperammonemia and unconsciousness following sodium valproate intoxication

Although valproic acid has gradually gained its popularity in the treatment of various seizure disorders, overdose of valproate is not common. An 18-y-old man with a history of epilepsy controlled by sodium valproate and clonazepam attempted suicide with an ingestion of 45 g sodium valproate. He presented to our service with drowsiness and irritability. Extremely high serum ammonia (623 ug/dL) and elevated serum valproate concentration (575 ug/mL) were found on admission. Several metabolic abnormalities, including hypernatremia, hypocalcemia and metabolic acidosis, as well as, increased serum transaminase levels were also recorded. With supportive measures, he became clear 24 h later and was discharged 6 d after ingestion. Serial follow-up of his serum valproate and ammonia levels disclosed a close relationship between these 2 measurables. After acute overdose of valproic acid, patients usually present with mild and generally reversible depression of the central nervous system. However, impairment of liver function, hyperammonemia, fluid-electrolyte disturbances, coma, seizures, hypotension and even death may occur following valproate overdose. Symptomatic and supportive measures are the mainstay in the treatment of valproic acid overdose. With prompt diagnosis and early institution of treatment, a complete recovery should be anticipated.

Bladder and rectal doses from external-beam boosts after gynecologic brachytherapy

PURPOSE

To establish a typical value for radiation doses under pelvic midline shields.

MATERIALS AND METHODS

Three methods were used to determine bladder and rectal doses under 5- or 6-half-value layer (HVL) shields for 10- and 24-MV external beams. First, dose was computed with a standard irregular field routine in 25 consecutive patients (aged 35-70 years) with stage IIB or IIIB disease treated with cesium-137 brachytherapy followed by a parametrial external-beam boost. Second, in vivo measurements with a solid-state probe were recorded during the first boost after completion of brachytherapy in each patient. Third, measurements obtained with an ionization chamber in a solid phantom (water-equivalent material) were compared with computed and in vivo results.

RESULTS

All three dosimetric methods yielded bladder and rectal doses higher than the commonly assumed 5% of the unshielded primary beam dose. Doses within the shielded volume may be as high as 15% of the unshielded dose. Doses are similar under 5- and 6-HVL midline shields. Often, the actual bladder and rectal doses exceeded the planned dose limits and their corresponding maximum radiation dose tolerance levels.

CONCLUSION

Bladder and rectal doses are higher than previously understood. Parametrial boosts may contribute as much as 3.0 Gy to the bladder and rectal doses.

Interaction of myocyte enhancer factor 2 (MEF2) with a mitogen-activated protein kinase, ERK5/BMK1

Myocyte enhancer factor 2 (MEF2) has been implicated in the complex hierarchical regulation of muscle-specific gene expression and differentiation. While the MyoD family members are able to initiate the skeletal muscle differentiation program, whether MEF2 is sufficient in directing skeletal muscle differentiation is still controversial. Furthermore, how MEF2 transactivates its target genes is not fully understood. It has been suggested that the interactions of MEF2 with other factors modify its transcriptional activity. Therefore, the identification of MEF2-interacting factors may be important in understanding the mechanism by which MEF2 activates its target genes. In this study, a mitogen-activated protein kinase (MAP kinase), ERK5/BMK1 was found to interact with MEF2 in a yeast two hybrid screen. The interaction was confirmed by a glutathione S -transferase-pull down assay and a co-immunoprecipitation study indicating that endogenous ERK5 and MEF2 interact with each other in vivo . The interacting domain of MEF2 was mapped to the N-terminus which contains the highly conserved MADS and MEF2 domains. Functionally, ERK5/BMK1 was able to phosphorylate MEF2 in vitro . Furthermore, when cotransfected with ERK5/BMK1, the transactivation capacity of MEF2 was enhanced. These results suggest that the functions of MEF2 could be regulated through ERK5/BMK1.

Dose volume histogram analysis of the gamma knife radiosurgery treating twenty-five metastatic intracranial tumors

Treating multiple brain metastatic sites in Gamma Knife radiosurgery is not uncommon. Most metastases can be treated with few or even one single shot. Occasionally we have patients returning for retreatment for different intracranial metastatic sites at different times. Dose distribution for these metastases are prescribed locally without considering the previous dose contribution. We present a study which simultaneously calculates the dose distribution of 25 randomly placed shots distributed inside the intracranial region. The Dose Volume Histogram (DVH) is plotted to study the coverage of the tumor sites and normal tissues. We have calculated ten DVH studies and show that 50% of the brain volume receives less than 500 cGy for the maximum tumor dose of 40 Gy, and the dose gradient is extremely steep. This DVH analysis shows that the Gamma Knife radiosurgery is a good treatment modality to control the local tumors while maintaining normal brain function, even for the large number of brain metastasis treated at different times.

Cardiac arrhythmia and betel nut chewing--is there a causal effect?

Betel nuts are widely ingested in many countries, including Taiwan. They stimulate various autonomic and CNS reactions, but there have been no reports of cardiac toxicity. We treated 2 patients with cardiac dysrhythmias thought due to betel nut chewing. In case 1, a 44-y-old previously healthy male presented with chest tightness, dyspnea, diaphoresis and palpitation immediately after chewing 1 betel quid. He soon became breathless and died despite immediate cardiopulmonary resuscitation. In Case 2, a 28-y-old man suffered palpitations, epigastralgia, and chest distress following consumption of 4 betel quid. Paroxysmal supraventricular tachycardia was noted and terminated by repeated verapamil administration. The pharmacological properties of betel nuts and the time sequence of these cases raise the possibility of betel nut-induced cardiac dysrhythmias. The number of betel nut chewers in Taiwan continues to increase, suggesting there may be other cases of betel nut-related cardiac toxicities in the future.

Mitochondrial myopathy with predominant respiratory dysfunction in a patient with A3243G mutation in the mitochondrial tRNA(Leu(UUR))gene

We report a patient with the A3243G point mutation of mitochondrial DNA (mtDNA) who presented with severe impairment of respiratory function and only mild involvement of limb muscles. This 55-year-old woman had a history of repeated episodes of respiratory failure unexplained by lung disease or central nervous system lesions. Needle electromyography suggested myopathy and muscle biopsy showed many ragged-red fibers. Molecular analysis of mtDNA in blood and muscle cells showed an A3243G point mutation in the tRNA(Leu(UUR))gene; the percentages of mutant mtDNA in blood and muscle cells were 65% and 71%, respectively. These findings suggest that mitochondrial myopathy should be considered as a cause of respiratory failure due to neuromuscular disorders, and that pure myopathy with predominant respiratory dysfunction is one of the heterogeneous phenotypic features associated with the A3243G point mutation of mtDNA.

Immunolocalization of transcription factor NF-kappaB in inclusion-body myositis muscle and at normal human neuromuscular junctions

To investigate whether nuclear factor kappaB (NF-kappaB) is involved in the pathogenesis of inclusion-body myositis (IBM), we immunostained muscle biopsies of eight patients with IBM with specific antibodies against its p50 and p65 subunits. Approximately 70% of IBM vacuolated muscle fibers had strong focal accumulations of both NF-kappaB p50 and p65, which by immunoelectronmicroscopy, localized mainly to clusters of paired-helical filaments (PHFs). Virtually all necrotic fibers, in various muscle biopsies, had diffusely strong p50 immunoreactivity, whereas p65 immunoreactivity was present only in a small subset of necrotic fibers. At all neuromuscular junctions, postsynaptically there was strong p65 but no p50 immunoreactivity. Our data suggest that NF-kappaB plays a role in IBM pathogenesis. Different distributions of NF-kappaB subunits in necrotic fibers and at normal neuromuscular junctions (NMJs) suggests different roles of each subunit in human muscle pathology and physiology.

Prolonged severe withdrawal symptoms after acute-on-chronic baclofen overdose

INTRODUCTION

Baclofen is frequently used to treat muscle spasticity due to spinal cord injury and multiple sclerosis. Baclofen overdose can lead to coma, respiratory depression, hyporeflexia, and flaccidity. An abrupt decrease in the dose of baclofen due to surgery or a rapid tapering program may result in severe baclofen withdrawal syndrome manifesting hallucinations, delirium, seizures, and high fever. Severe baclofen withdrawal syndrome secondary to intentional overdose, however, has not received mention.

CASE REPORT

A 42-year-old male receiving chronic baclofen therapy, 20 mg/d, attempted suicide by ingesting at least 800 mg of baclofen. He was found in coma 2 hours postingestion with depressed respirations, areflexia, hypotonia, bradycardia, and hypotension. Treatment with intravenous fluids, atropine, dopamine, and hemodialysis was associated with restoration of consciousness within 2 days but disorientation, hallucinations, fever, delirium, hypotension, bradycardia, and coma developed during the following week. Baclofen withdrawal syndrome was not diagnosed until hospital day 9, when reinstitution of baclofen rapidly stabilized his condition. Oral overdosage of baclofen causes severe neurological and cardiovascular manifestations due to its GABA and dominant cholinergic effects. Severe baclofen withdrawal syndrome is manifest by neuropsychiatric manifestations and hemodynamic instability. Caution should be exercised after a baclofen overdose in patients receiving chronic baclofen therapy.

Neuroanatomy of the penile portion of the human dorsal nerve of the penis

OBJECTIVE

To determine the distribution of the dorsal nerve of the penis (DNP), the principal somatosensory nerve innervating the phallus, along the penile shaft and within the glans penis.

MATERIALS AND METHODS

The DNP was dissected in human autopsy specimens, using low magnification, following the course of the nerve from the symphysis pubis into the glans penis.

RESULTS

The shaft and glans were innervated by separate populations of axons. The lateral and ventral portions of the penile shaft were innervated by branches arcading from the dorsal midline radiating toward the ventral surface. These branches were very variable and some were seen to penetrate the corpus spongiosum. The axons innervating the glans were constant in a dorsal, midline location along most of the penile shaft, and once within the glans, there was abundant branching. Undulations in the nerves were noted along the penile shaft.

CONCLUSIONS

The lateral arcading branches of the DNP provide a sensory pathway on the ventral and lateral penile shaft, and the termination of the fibres at the corpus spongiosum is consistent with pudendal innervation of the penile urethra. The distinct pattern of innervation of the glans emphasizes the role of the glans as a sensory structure. These findings may aid in planning penile surgical procedures.

The present and future of poison control center in Taiwan

The PCC-Taiwan was founded in July 1985 under the auspices of the Department of Health, Executive Yuan, and the Veterans General Hospital-Taipei, Republic of China. It has served a population of 21 million inhabitants on a 24-hours basis. It has also served as a referral center for treating poisoning cases nationwide, a training center for physicians and consultants, and a center for Analytical Toxicology. The average annual volume of telephone inquires to PCC is more than four thousand in recent few years and continue to increase annually. The present and future prospective of the PCC-Taiwan which have to be accomplished are: 1. to propagate public education of poisoning prevention and increase the utility of PCC before events of intoxication, 2. to establish, computerize and improve the database and network of domestic poisonous products or natural toxins, including herbs, 3. to establish an nationwide referral network for severely poisoned patients or cluster poisoning events, 4. to build up a global collaborative work with other poison centers.

Nitric oxide-induced oxidative stress in autosomal recessive and dominant inclusion-body myopathies

Autosomal-recessive and autosomal-dominant hereditary inclusion-body myopathies are severe, progressive muscle diseases, characterized pathologically by vacuolated muscle fibres containing paired helical filaments. We immunostained muscle biopsy specimens from quadriceps-sparing autosomal-recessive and autosomal-dominant inclusion-body myopathy subjects, disease-control subjects and normal patients, utilizing isoform-specific antibodies against the neuronal and inducible forms of nitric oxide synthase, and antibodies against nitrotyrosine. Approximately 75% of the vacuolated muscle fibres in all recessive and dominant inclusion-body myopathy patients contained inclusions strongly immunoreactive with antibodies against neuronal and inducible nitric oxide synthase which, by immunoelectron microscopy, were colocalized to clusters of tubulofilaments (previously shown, by us, to be paired helical filaments). Strong nitrotyrosine immunoreactivity was in the form of multiple dots and large granular patches, which ultrastructurally did not immunolocalize to tubulofilaments. Excess intracellular nitric oxide can combine with superoxide to produce highly toxic peroxynitrite, which can nitrate tyrosines of proteins. The presence of nitrotyrosine is indicative of nitric oxide-induced oxidative stress. Our data suggest that oxidative stress plays a role in the pathogenic cascade of hereditary inclusion-body myopathies.

Peripheral distribution of the human dorsal nerve of the penis

PURPOSE

The integrity of the dorsal nerve of the penis is crucial for normal erectile and ejaculatory function. To our knowledge a description of this nerve along the phallus has not been formally described. We illustrate the distribution of the dorsal nerve of the penis to the penile shaft, anterior urethra and glans.

MATERIALS AND METHODS

Neuroanatomical dissections were performed on 28 cadaver penis specimens. Electrodiagnostic testing was conducted on 10 healthy male subjects to confirm the anatomical findings.

RESULTS

The dorsal nerve of the penis consists of 2 populations of axons, one to innervate the penile shaft and urethra, and the other to innervate the glans. Stimulation of the urethra resulted in responses recorded in the main trunk of the dorsal nerve of the penis and stimulation of the nerve evoked responses within the urethra. Bulbocavernosus muscle contraction was elicited following urethral stimulation.

CONCLUSIONS

Urethral innervation by the dorsal nerve of the penis supports the view that urethral afferent impulses are a component of reflex ejaculatory activity. The pattern of glanular innervation by the dorsal nerve of the penis identifies the glans as a sensory end organ for sexual reflexes. The undulating character of the dorsal nerve of the penis is a mechanism by which the nerve can accommodate to significant changes in penile length with erection. Electrodiagnostic studies of the dorsal nerve of the penis should be modified to consider the anatomical findings.

Clinical experience with pendimethalin (STOMP) poisoning in Taiwan

The herbicide pendimethalin (STOMP) shares a similar chemical structure with nitro compounds such as dinitrobenzene, which was previously demonstrated to cause methemoglobinemia in mammals. However, reports on STOMP poisoning in humans are rare. We reviewed 71 STOMP poisoning cases (42 men and 29 women of mean age 43.9 +/- 2.5 y) reported to the Poison Control Center--Taiwan from September 1986 to September 1997 and summarized their clinical manifestations. Two incidences resulted from skin and eye contact. The rest were due to oral ingestion intentionally or accidentally. The average ingestion was 106.1 +/- 13.4 ml. Among them, 20 cases had no symptoms or signs, 38 had mild effects such as nausea, vomiting and sore throat, 7 had effects such as severe retching, hematemesis and seizures. Four patients expired due to also taking other herbicides (mainly organophosphates) and because of inadequate airway management. Adequate ventilation support was the major therapy in salvaging the poisoning cases.