Narrow-band imaging with magnifying endoscopy for the screening of esophageal cancer in patients with primary head and neck cancers

BACKGROUND AND STUDY AIM

Although narrow-band imaging (NBI) in endoscopy can improve detection of early-stage esophageal malignancies in patients with head and neck cancers, false-positive results may be obtained in areas with nonspecific inflammatory changes. This study evaluated the feasibility of primary screening with NBI and magnification for the presence of esophageal malignancies in these cancer patients.

PATIENTS AND METHODS

Sixty-nine patients with documented head and neck cancers were enrolled from April 2008 to January 2009. All patients underwent a meticulous endoscopic examination of the esophagus using a conventional white-light system followed by re-examination using the NBI system and final confirmation with NBI plus magnification.

RESULTS

Twenty-one patients (30.4 %) were confirmed to have esophageal neoplasia. Among these 21, 16 (76.2 %) had synchronous lesions, 9 (42.9 %) were asymptomatic, and 10 (47.6 %) had early-stage neoplasia. The incidence of multiple esophageal neoplasia was 57.1 %. NBI was more effective than conventional endoscopy in detecting neoplastic lesions (35 lesions in 21 patients vs. 22 lesions in 18 patients) and was particularly effective in patients with dysplasia (13 lesions in 9 patients vs. 3 lesions in 3 patients). The sensitivity and accuracy of detection were 62.9 % and 64.4 % for conventional endoscopy, 100 % and 86.7 % for NBI alone, and 100 % and 95.6 % for NBI with high magnification, respectively.

CONCLUSIONS

Compared with current approaches, NBI followed by high magnification significantly increases the accuracy of detection of esophageal neoplasia in patients with head and neck cancers. The result warrants conducting prospective randomized controlled study to confirm its efficacy.

Biophotonic Tools in Cell and Tissue Diagnostics

In order to maintain the rapid advance of biophotonics in the U.S. and enhance our competitiveness worldwide, key measurement tools must be in place. As part of a wide-reaching effort to improve the U.S. technology base, the National Institute of Standards and Technology sponsored a workshop titled "Biophotonic tools for cell and tissue diagnostics." The workshop focused on diagnostic techniques involving the interaction between biological systems and photons. Through invited presentations by industry representatives and panel discussion, near- and far-term measurement needs were evaluated. As a result of this workshop, this document has been prepared on the measurement tools needed for biophotonic cell and tissue diagnostics. This will become a part of the larger measurement road-mapping effort to be presented to the Nation as an assessment of the U.S. Measurement System. The information will be used to highlight measurement needs to the community and to facilitate solutions.

Interleukin-1 alpha polymorphism has influence on late-onset sporadic Parkinson's disease in Taiwan

Inflammatory events may contribute to the pathogenesis of Parkinson's disease (PD) and interleukin 1 (IL-1) may exert both neurotoxic and neuroprotective effects. We conducted a case-control study in a cohort of 493 PD cases and 388 ethnically matched controls to investigate the association of IL-1alpha C-889T and IL-1beta C-511T polymorphisms with the risk of PD. No significant difference in the genotype distribution of the analyzed polymorphisms was found between PD and controls. However, after stratification by age, individuals over 70 years of age carrying IL-1alpha-889 C/T genotype demonstrated a significant decrease in risk of developing PD (OR = 0.44; 95% CI = 0.22-0.88, p = 0.021) and the decrease is strengthened by IL-1beta-511 T-carrying genotype (OR = 0.28; 95% CI = 0.11-0.71, p = 0.008). Our data suggest that IL-1alpha, acting synergistically with IL-1beta, plays role in PD susceptibility among Taiwanese people older than 70 years of age.

Heat shock protein 70 and tumor necrosis factor alpha in Taiwanese patients with dementia

This study was to determine whether polymorphisms of heat shock protein 70-1 (HSP70-1) and tumor necrosis factor alpha (TNF-alpha) are associated with the risk of Alzheimer's disease (AD) and vascular dementia (VaD). Using the criteria of the NINCDS-ADRDA and NINDS-AIREN, 125 AD patients, 57 VaD patients and 109 ethnically matched nondemented controls were enrolled. The HSP70-1 -110 A/C and TNF-alpha -1031 T/C, -863 C/A and -857 C/T polymorphisms were analyzed by means of genotype or haplotype association methods. None of the four genotypes examined showed a statistically significant difference in genotype distribution between the AD cases and controls. However, the HSP70-1 -110 CC genotype occurred more frequently among AD cases (p=0.0821; odds ratio: 2.08; 95% confidence interval, CI: 0.92-4.98). The overall genotype distribution among the VaD cases tended to be different at the HSP70-1 -110 and TNF-alpha -1031 sites (p=0.0604 and 0.0316, respectively). The HSP70-1 -110 CC genotype was more frequent (p=0.0459), and the association of the -110 CC genotype with VaD was evident (p=0.0207; odds ratio: 3.22; 95% CI: 1.20-8.87). The more frequent TNF-alpha -1031 TC genotype (p=0.0614) was also evidently associated with VaD (p=0.0209; odds ratio: 2.32; 95% CI: 1.14-4.78). Multivariate analysis demonstrated the synergistic effect of the HSP70-1 -110 CC and TNF-alpha -1031 TC/CC genotypes on VaD (p=0.0091; odds ratio: 10.09; 95% CI: 2.01-75.97). Haplotype analysis among TNF-alpha -1031, -863, -857 sites revealed that -1031C-857C may act as a risk haplotype among VaD cases (p=0.0132, odds ratio: 2.26; 95% CI: 1.19-4.33). Our results suggest a potential protective role for HSP70 in both VaD and AD, whereas TNF-alpha may act as a risk factor only for VaD, and not for AD.

Genetic testing in spinocerebellar ataxia in Taiwan: expansions of trinucleotide repeats in SCA8 and SCA17 are associated with typical Parkinson's disease

DNA tests in normal subjects and patients with ataxia and Parkinson's disease (PD) were carried out to assess the frequency of spinocerebellar ataxia (SCA) and to document the distribution of SCA mutations underlying ethnic Chinese in Taiwan. MJD/SCA3 (46%) was the most common autosomal dominant SCA in the Taiwanese cohort, followed by SCA6 (18%) and SCA1 (3%). No expansions of SCA types 2, 10, 12, or dentatorubropallidoluysian atrophy (DRPLA) were detected. The clinical phenotypes of these affected SCA patients were very heterogeneous. All of them showed clinical symptoms of cerebellar ataxia, with or without other associated features. The frequencies of large normal alleles are closely associated with the prevalence of SCA1, SCA2, MJD/SCA3, SCA6, and DRPLA among Taiwanese, Japanese, and Caucasians. Interestingly, abnormal expansions of SCA8 and SCA17 genes were detected in patients with PD. The clinical presentation for these patients is typical of idiopathic PD with the following characteristics: late onset of disease, resting tremor in the limbs, rigidity, bradykinesia, and a good response to levodopa. This study appears to be the first report describing the PD phenotype in association with an expanded allele in the TATA-binding protein gene and suggests that SCA8 may also be a cause of typical PD.

Covered retrievable tracheobronchial hinged stent: an experimental study in dogs

PURPOSE

To evaluate the safety and technical feasibility of the use of a covered retrievable tracheobronchial hinged stent and investigate the histopathologic airway changes after placement and removal of the stent in dogs.

MATERIALS AND METHODS

The experimental stent was composed of tracheal and bronchial stents that were connected together at their ends. Each stent was woven from a single thread of 0.2-mm-diameter nitinol wire filament in a tubular configuration and covered with polyurethane solution by a dipping method. Drawstrings were attached at the upper end of the tracheal stent for stent removal. Under fluoroscopic guidance, 20 stents were placed at the lower trachea and left main bronchus in 20 dogs and were electively removed 4 weeks (n = 10) or 8 weeks (n = 10) after placement. Ten dogs were killed just after stent removal and the remaining 10 were killed 2 weeks after stent removal.

RESULT

Stents were successfully placed in all dogs. Pneumonia was observed in three dogs. Stent migration occurred in seven dogs (35%). Except for two cases of stent expectoration, 18 stents were easily removed within a few minutes. There was considerable granulation tissue proliferation and inflammatory reaction in the airways of the dogs that were killed just after stent removal. The pathologic changes of the airways returned to almost-normal conditions 2 weeks after stent removal.

CONCLUSION

Placement and removal of a covered retrievable tracheobronchial hinged stent seems to be feasible, and histopathologic changes of the airway related to the stents returned to normal 2 weeks after stent removal.

Solitary fibrous tumor in the buccal space: MR findings with pathologic correlation

We report MR findings in a case of a solitary fibrous tumor involving the buccal space in a middle-aged man. On MR images, most of the mass was isointense and hyperintense to the muscle on T1- and T2-weighted images, respectively, and showed homogeneously strong enhancement on contrast-enhanced T1-weighted images. The medial peripheral portion, which was isointense on T2-weighted images and showed less enhancement on contrast-enhanced T1-weighted images, corresponded to the hypocellular and collagenous sclerotic area on pathologic correlation.

Metallothionein induction in early larval stages of tilapia (Oreochromis mossambicus)

Amounts of whole-body metallothionein (MT) in tilapia (Oreochromis mossambicus) larvae increased to a peak (1,500 ng mg(-1) protein) 1 d after hatching (H1), decreased rapidly thereafter, and was maintained at a constant level (700 ng mg(-1)) 3 d after hatching (H3). Waterborne Cd(2+) could stimulate MT expression in newly hatched (H0) larvae in dose-dependent and time-dependent patterns. H0 larvae, which were treated with 35 microg L(-1) Cd(2+) for 24 h, showed a 1.7-fold increase in the MT amount (174.0+/-64.7) and a 6. 5-fold increase in accumulated Cd(2+) but no significant change in Ca(2+) content, compared with the H0 control (MT, 102.6+/-48.1). H3 larvae with the same treatment revealed about a 10-fold increase in accumulated Cd(2+), a 10% decrease in Ca(2+) content, but no change in MT (261.2+/-120.0), compared with the H3 control (MT, 330+/-74.0). H0 larvae could synthesize more MT to bind Cd(2+) for detoxification in 35 microg L(-1) Cd(2+), a dose that would not affect normal physiology or survival of H0 larvae. On the other hand, 35 microg L(-1) Cd(2+) caused H3 larvae to experience hypocalcemia, an abnormal physiological condition, in which H3 larvae could not synthesize sufficient MT, thus causing greater than 25% mortality. These results indicate for the first time that the inducibility of MT by waterborne Cd(2+) is development dependent, being correlated with inconsistent sensitivities to Cd(2+) during larval development.

Cardiac and pulmonary vagal neurons receive excitatory chemoreceptor input

The effects of hypercapnia and hypocapnia on the activities of the cardiac and pulmonary vagal single fibers were examined in the decerebrated, unanesthetized, paralyzed, and vagotomized cats. The animals breathed 100% O2. Fractional end tidal CO2 concentration was raised to 9% by adding CO2 into the O2 inlet. Average discharge rate of efferent cardiac vagal units (n=10) increased from 1.0+/-0.3 to 2.2+/-0.3 Hz. Hypocapnia apnea was produced by hyperventilation. Activities of cardiac vagal units tested (n = 4) showed dramatic decrease (0.1+/-0.0 Hz). Mean arterial blood pressure did not change significantly under these conditions. In contrast, only instantaneous firing rate during inspiration was significantly increased for efferent pulmonary vagal units (n = 11) during hypercapnia. The activities of the 3 pulmonary vagal units tested with hypocapnia decreased significantly. We concluded that cardiac and pulmonary vagal neurons were excited by chemoreceptor input.

Pleural and pulmonary staining at inferior phrenic arteriography mimicking a tumor staining of hepatocellular carcinoma

PURPOSE

To describe the findings of pleural and pulmonary staining of the inferior phrenic artery, which can be confused with tumor staining during transarterial chemoembolization (TACE) of hepatoma.

METHODS

Fifteen patients who showed pleural and pulmonary staining without relationship to hepatic masses at inferior phrenic arteriography were enrolled. The staining was noted at initial TACE (n = 8), at successive TACE (n = 5), and after hepatic surgery (n = 2). The angiographic pattern, the presence of pleural change on computed tomography (CT), and clinical history were evaluated.

RESULTS

Draining pulmonary veins were seen in all cases. The lower margin of the staining corresponded to the lower margin of the pleura in 10 patients. CT showed pleural and/or pulmonary abnormalities in all cases. After embolization of the inferior phrenic artery, the accumulation of iodized oil in the lung was noted.

CONCLUSION

Understanding the CT and angiographic findings of pleural and pulmonary staining during TACE may help differentiate benign staining from tumor staining.

Percutaneous placement of self-expandable metallic biliary stents in malignant extrahepatic strictures: indications of transpapillary and suprapapillary methods

OBJECTIVE

To compare the efficacy of suprapapillary and transpapillary methods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied.

MATERIALS AND METHODS

Stents were placed in 59 patients. Strictures were categorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n = 16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared.

RESULTS

Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p <0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapapillary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p = 0.37) or method (p = 0.62).

CONCLUSION

For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.

Colonic wall thickening in cirrhotic patients: CT features and its clinical significance

BACKGROUND

To evaluate the computed tomographic (CT) features of colonic wall thickening in cirrhotic patients and to determine their prognostic value.

METHODS

We retrospectively reviewed 28 cirrhotic patients with colonic wall thickening (>/=10 mm) on CT. Twenty-six of the 28 patients had hepatocellular carcinoma. The severity of hepatic dysfunction was determined by using the Child-Pugh classification. We analyzed the patterns of bowel wall thickening and degree of portal hypertension on CT and the survival periods after initial CT detection of colonic wall thickening.

RESULTS

The involved segment of the colon was diffusely thickened with either scalloped or nodular circumferential configuration. In all patients, the thickened colonic wall enhanced poorly. Although the ascending colon was involved in all patients, the transverse (n = 14) or descending (n = 5) colon was also simultaneously involved. Most patients exhibited an advanced stage of portal hypertension on CT. The median survival period of 25 patients who expired was 34 days, and 21 patients (84%) expired within 3 months.

CONCLUSIONS

Colonic wall thickening on CT can be used as one of the indicators of poor prognosis in cirrhotic patients. Advanced liver cirrhosis with significantly severe dysfunction is the likely cause of mortality. Therefore, a less aggressive therapeutic approach is recommended if hepatocellular carcinoma is coexistent in these patients.

The removal of beta-2-microglobulin by an immunoadsorption wall

The accumulation of beta-2-microglobulin (beta2M) in collagen-rich tissues has been proven to be the main cause of dialysis related amyloidosis. However, it remains uncertain which technique for the removal of beta2M can be used without compromising the advantages of other dialysis strategies. A new concept, an immunoadsorption wall, which combines the principles of immunoisolation and immunoadsorption is proposed to remove beta2M. The present investigations suggested that the application of the concept to clinical use is feasible and worthwhile. The concept, if validated, will help shape a novel multitask type of artificial kidney based on the combination of different separation technologies.

A single minute lesion around the ventral respiratory group in medulla produces fatal apnea in cats

In 35 adult cats anesthetized with intraperitoneal chloralose and urethane, the ventrolateral medulla was explored by microinjection of kainic acid (KA, 24 mM, 200 nl) with metal electrode-tubing or glass micropipette to determine regions which elicit persistent apnea. Persistent apnea is defined as: (1) In spontaneously breathing cats, termination of respiration over 3 min with a decrease of the mean systemic arterial pressure (MSAP) to 25 mm Hg. (2) In animals under artificial ventilation and paralyzed by gallamine, cessation of bilateral phrenic nerve (PNA) activities over 25 min. The apnea producing area was located dorsal to the rostral pole of the lateral reticular nucleus, ventromedial to the ambiguous nucleus and immediately caudal to the retrofacial nucleus. Functionally, this region includes the rostral part of the ventral respiratory group (rVRG) encompassing the pre-BOtzinger area. We define this region as the VRG apnea producing area (VRG-Apa). Fatal apneusis was observed under following conditions: (1) Persistent apnea was produced after a single KA microinjection in one side of the VRG-Apa (5 animals). Microinjection of sodium glutamate (0.25 M, 70-200 nl) in the same area produced only brief apnea, while microinjection of kynurenic acid (0.1 M, 200 nl) showed little effect on the respiration but slightly increased the SAP. (2) Positioning an electrode nearby but not in the VRG-Apa with or without KA injection did not produce apnea. But when a second electrode insertion to the opposite VRG-Apa immediately produced persistent apnea even without KA injection (6 animals). (3) Midsagittal division of the medulla 0-5 mm rostral to the obex produced persistent silence of PNA on both sides in artificial ventilated animals (7 animals), while similar division 0-5 mm caudal to the obex (4 animals) produced a brief but reversible quiescence of PNA. In conclusion, findings of the present study support the existence of a restricted region of VRG-Apa. VRG-Apa on both sides are closely connected, and integrity of both VRG-Apa is essential for normal respiration.

Pharmacological properties of ACh receptors on the heart of the marine bivalve Meretrix lusoria

The cholinergic receptors on the heart of the marine bivalve Meretrix lusoria were used as a model to investigate their pharmacological properties in bivalves. By recording method, we measured the contractile force (CF) and the heart rate (HR) of the heart to examine the characteristics of cholinergic receptors of a marine bivalve. The known ACh receptor agonists or antagonists in vertebrate nervous system were then introduced into the heart by perfusion, to monitor their effects upon heart activities. Of the six tested agonists, two mAChR agonists (OXA-22, bethanechol) and two nAChR agonists (methylcarbachol, nicotine) mimicked the response induced by ACh. Among the seven tested antagonists, three mAChR antagonists (trihexyphenidy1, atropine and scopolamine) and three nAChR antagonists (TEA, curare and hexamethonium bromide) showed the antagonistic effects on the inhibition induced by ACh. However, there was one mAChR agonist, metoclopramide, that behaved like an ACh antagonist. Both APE (mAChR agonist) and PTMA (nAChR antagonist) showed no significant effects. This differences suggest that the pharmacological characteristics of ACh receptors on the heart of bivalve are different from those in vertebrates. It may be a novel type of ACh receptors.

Respiratory-related facial nerve activity in response to activation of the rostral ventrolateral medulla in the cat

The effects of electrical and chemical activation of the rostral ventrolateral medulla (rVLM) on respiratory-related facial nerve activity were investigated in decerebrated, paralyzed, vagotomized and ventilated cats. The animal was maintained at normocapnia and hypercapnia in hyperoxia. Phrenic and facial nerve activities were simultaneously recorded. Excitation of the rVLM either by electrical current (12.5 to 50 microA, 80 Hz and 0.5 ms pulse duration) or glutamate microinjection (50 mM, 20 to 200 nl) inhibited both phrenic and facial nerve discharges. Although inhibition of the rVLM upon both nerves was attenuated by hypercapnia, this inhibition remained significant during hypercapnia. These results suggest that the rVLM may be involved in the modulation of upper airway patency by controlling respiratory-related facial nerve activity.

Hemodialysis alternative with ascites ultrafiltration for an end-stage renal failure patient associated with tense ascites secondary to decompensated liver cirrhosis

Patients with end-stage renal disease combined with tense ascites caused by decompensated liver cirrhosis are sometimes encountered in a hemodialysis center. A big problem for the management of these patients is the tendency of hypotension during ultrafiltration. Subsequent fluid accumulation, especially in the abdominal cavity, causes breathing difficulty and abdominal discomfort. We present a new technique, ascites ultrafiltration, to solve this problem. Using the same equipment as for ordinary hemodialysis, and incurring the same cost, we removed directly approximately 8 L of ascites fluid during each nearly 4-hour session. No hemodynamic instability was noted. We proved this technique to be an effective and safe alternative method for this group of patients.

Frostbite of the face after recreational misuse of nitrous oxide

Exposure of the skin to nitrous oxide, a liquified gas stored under pressure in a cylinder, can occur in anaesthesiologists and in those involved in recreational misuse of the gas. A case is reported of a man who presented to the emergency department after sniffing nitrous oxide and sustaining frostbite injury to his left cheek. Conservative management of this injury allowed spontaneous separation of the necrotic tissue and healing of the granulating wound by contraction.

Severe burn injury from recreational gasoline use

This report describes the case of a 13-year-old boy who suffered severe burns with inhalation injury during the recreational use of gasoline. Gasoline sniffing is a popular form of solvent abuse for young children and adolescents in isolated, rural communities. In addition to the neurological and physiological complications of gasoline inhalation, gasoline sniffers face the significant threat of severe burn injury or death resulting from ignition of the gasoline vapor as well as from extensive physical contact with the constituents of liquid gasoline.

Investigation of upper gastrointestinal hemorrhage in chronic renal failure

The role of specific pathological findings in the upper gastrointestinal tract in chronic renal failure remains uncertain. Most of the studies were conducted in the West, and the number of subjects was small. We have tried to look at that problem in Taiwan. Endoscopy to evaluate the source of upper gastrointestinal hemorrhage was performed in 698 patients over a 37-month period; that represents 4.4% of all patients undergoing upper gastrointestinal endoscopy for miscellaneous reasons in that time span. Fifty-eight patients (8.3%) who had been hemodialyzed for chronic renal failure were selected, as were 640 control patients who did not have renal failure. Patients with renal transplant were not included. Endoscopic diagnoses, contributing factors of bleeding, and the course and outcome of the hospitalization were analyzed. chi 2 Test with or without Yates' correction and Student's t test were used as appropriate. Erosive gastritis was the most frequent source of bleeding in patients with chronic renal failure. Erosive gastritis (p < 0.005), erosive esophagitis (p < 0.001), and esophageal ulcer (p < 0.005) were significantly more common causes of bleeding in the renal failure population than in the group without renal failure. The two groups did not differ significantly (p > 0.05) in smoking, heavy alcohol intake, or use of ulcerogenic medications. The age was older (64.1 +/- 11.4 vs. 55.7 +/- 16.2 years) and the mortality rate higher (13% vs. 2%) in patients with renal failure than in those without. The differential diagnoses of upper gastrointestinal bleeding sites differ in patients with and without chronic renal failure; they are diverse. However, erosive gastritis, rather than gastric ulcer or duodenal ulcer, is the most common cause in the patients with renal failure. The mortality rate is significantly higher in these patients than in the general population.

Changes in phrenic, hypoglossal and recurrent laryngeal nerve activities after intravenous infusions of aminophylline in cats

Aminophylline is known to have respiratory stimulant properties, and it has been suggested that it may also be effective in sleep apnoea. However, its role in this disorder remains uncertain. Theoretically, increasing upper airway motoneural activity in order to maintain airway patency might alleviate obstructive sleep apnoea. On the other hand, increasing the respiratory drive may also prove beneficial in treating central sleep apnoea. In these studies, we attempted to determine the effect of aminophylline on neural activities of the upper airway and diaphragm. We administered intravenously either a low dose (4 mg.kg-1) or a high dose (16 mg.kg-1) of aminophylline to decerebrated, vagotomized and paralysed cats, and continuously recorded the phrenic hypoglossal and recurrent laryngeal nerve activities for 3 h. Results showed that a high dose of aminophylline induced a marked increase in phrenic nerve activity, but not hypoglossal or recurrent laryngeal nerve activity. In a group treated with a low dosage of aminophylline, a significant increase of activity was found in all three nerves. Furthermore, phrenic nerve activity increased more with a high dose than with a low dose. We confirmed that aminophylline has dose-dependent and selective effects on respiratory neural activity. A low dose acts on the upper airway and diaphragm, but a high dose induces a marked increase in central respiratory drive. According to our results, low dose aminophylline might be beneficial in obstructive sleep apnoea, whereas, a high or low dose might improve some cases of central sleep apnoea.

Changes in phrenic, hypoglossal and recurrent laryngeal nerve activities after intravenous infusions of aminophylline in cats

Aminophylline is known to have respiratory stimulant properties, and it has been suggested that it may also be effective in sleep apnoea. However, its role in this disorder remains uncertain. Theoretically, increasing upper airway motoneural activity in order to maintain airway patency might alleviate obstructive sleep apnoea. On the other hand, increasing the respiratory drive may also prove beneficial in treating central sleep apnoea. In these studies, we attempted to determine the effect of aminophylline on neural activities of the upper airway and diaphragm. We administered intravenously either a low dose (4 mg.kg-1) or a high dose (16 mg.kg-1) of aminophylline to decerebrated, vagotomized and paralysed cats, and continuously recorded the phrenic hypoglossal and recurrent laryngeal nerve activities for 3 h. Results showed that a high dose of aminophylline induced a marked increase in phrenic nerve activity, but not hypoglossal or recurrent laryngeal nerve activity. In a group treated with a low dosage of aminophylline, a significant increase of activity was found in all three nerves. Furthermore, phrenic nerve activity increased more with a high dose than with a low dose. We confirmed that aminophylline has dose-dependent and selective effects on respiratory neural activity. A low dose acts on the upper airway and diaphragm, but a high dose induces a marked increase in central respiratory drive. According to our results, low dose aminophylline might be beneficial in obstructive sleep apnoea, whereas, a high or low dose might improve some cases of central sleep apnoea.

Bilateral amputations following hydrotherapy tank burns in a paraplegic patient

Hydrotherapy is an important part of wound care and physical therapy. The benefits of hydrotherapy are derived from water's cleansing ability, buoyancy, drag, inertia and temperature. If the temperature of the water is not adequately controlled, an immersion scald burn can occur. A paraplegic patient who was receiving hydrotherapy for treatment of his malleolar ulcers sustained immersion scald burns that ultimately necessitated below-the-knee amputations.

Facilitation and inhibition of phrenic motoneuronal activities by lung inflation

The purpose was to evaluate the facilitatory influence of pulmonary inflations on phrenic activity. In decerebrate cats, activities of phrenic motoneurons and nerve were recorded during ventilatory cycles in which the lungs were inflated to different levels and inflations were withheld. Motoneuronal activities were divided into "early" and "late" populations depending on their onset of activity. In normocapnia, facilitation was manifested by an increase in the rate of rise of phrenic activity. Facilitation increased with an increased level of inflations and fell when inflations were withheld. This facilitation was largely due to an increased rate of change and earlier onset of late motoneuronal activities. These variables for early motoneuronal activities were little altered by changes in inflations. Peak discharge frequencies of both early and late motoneurons increased during noninflation cycles. Facilitation was still evident during hypercapnia and in anesthetized animals; however, under these conditions, the earlier onset of late motoneuronal activities was no longer observed. We conclude that facilitation by pulmonary stretch receptor discharge is a constant determinant of phrenic neuronal and neural activities.

Differential effects on sympathetic nerve activities elicited by activation of neurons in the pressor areas of dorsal and rostral ventrolateral medulla in cats

Changes of the nerve activity of the sympathetic renal and vertebral nerves were elicited by microinjection of sodium glutamate (50 nmol/100 nl) into the pressor areas of the dorsal (DM) and rostral ventrolateral medulla (RVLM) in cats under urethane-chloralose anesthesia. Animals were bilaterally vagotomized, artificially ventilated, and paralyzed with gallamine triethiodide. The vertebral nerve activity always increased when pressor responses were induced by DM or RVLM stimulation. However, the effects of medullary stimulation on the renal nerve activity were variable. Three types of renal nerve responses concomitant with the pressor responses were observed in either baroreceptor-intact or baroreceptor-denervated cats. They were: (1) augmentation (type I); (2) attenuation (type II); and (3) insignificant change (type III). Type I responses were often elicited by RVLM stimulation whereas type II responses were often elicited by DM stimulation. Findings suggested that neurons integrating these sympathetic nerve activities were not equally distributed in the pressor areas of DM and RVLM. This result supports the notion that neurons located in different pressor areas of the brainstem exert differential effects over different sympathetic nerve activities.

Activity of abdominal muscle motoneurons during hypercapnia

Our purpose was to examine the influence of hypercapnia on the activity of motoneurons innervating the transversus abdominis and internal oblique abdominal muscles, and of integrated phrenic and abdominal motor nerve activities. Studies were done in nine adult cats that were decerebrated, vagotomized, thoracotomized, paralyzed and ventilated mechanically. Of 42 motoneurons examined, 24 showed strong respiratory modulation (RM neurons), with the discharge confined primarily to the central expiratory period. The remaining 18 motoneurons discharged tonically, and failed to show respiratory modulation even at increased levels of central respiratory drive. Hyperoxic hypercapnia augmented the activities of the phrenic and abdominal nerves and increased the early expiratory discharge frequency of the RM neurons. The hypercapnia-induced increase in firing frequency during early expiration was accompanied by a corresponding decline in late expiration, and a virtual abolition of the inspiratory activity in the few neurons that discharged in this phase under normocapnic conditions. Finally, hypercapnia induced an increase in the number of spikes generated during each expiratory period in about half of the RM neurons, whereas the remaining cells showed a decrease. Thus, the increased peak activity of the integrated whole abdominal nerve burst with hypercapnia was brought about by a shift in the temporal pattern of motoneuron firing, or by an increase in the number of spikes generated during the expiratory period. The steep rate of rise and the pronounced early expiratory peak observed in the integrated abdominal nerve burst during hypercapnia in this preparation are consistent with the increase in motoneuron firing frequency during the early stages of the expiratory phase.

Presence of neuronal cell bodies in the sympathetic pressor areas of dorsal and ventrolateral medulla inhibiting phrenic nerve discharge in cats

To examine whether neuronal cell bodies (perikarya) in the pressor areas of dorsal medulla or ventrolateral medulla also modulate respiratory function, phrenic nerve activity was monitored and correlated with the pressor response in chloralose-urethane anaesthetized cats. The animals were paralyzed and artificially ventilated maintaining the end-tidal fractional concentration of CO2 at 0.04-0.05. The same pressor point in the dorsal or ventrolateral medulla was stimulated electrically (rectangular pulse of 20-200 microA, 80 Hz and 0.5 ms) and then chemically (0.25-0.5 M sodium glutamate, 80-200 nl). Areas producing pressor effects in either the dorsal or ventrolateral medulla produced a current-dependent decrease of phrenic discharge. The decrease in Pna was significant when the electrical current reached 50 microA or above. It occurred immediately before the onset of increase in blood pressure. Injection of glutamate to the same pressor point in either the dorsal or ventrolateral medulla produced a similar decrease in phrenic nerve activity. The results suggest that in the pressor areas of dorsal and ventrolateral medulla there are neuronal perikarya that can increase systemic arterial pressure and inhibit phrenic nerve activity. Whether the same or separate neurones are responsible for these responses is to be determined.

Correlation of cardiovascular and respiratory responses to glutamate excitation of pressor areas of the medulla in cats

Cardiorespiratory responses, including changes of systemic arterial pressure (SAP), renal or splanchnic sympathetic nerve activity (SNA) and phrenic nerve activity (PNA), were elicited by microinjection of monosodium glutamate solution (0.5 M, 100 nl) into the dorsal (DM) and rostral ventrolateral medulla (RVLM) in 15 vagotomized cats anesthetized by urethane-chloralose and paralyzed by gallamine triethiodide. Artificial ventilation was adjusted to keep the end-tidal CO2 concentration at 4.0-0.5%. Sixty two pressor and 17 non-pressor sites were stimulated. Most of the stimulations inhibited the PNA. The responses of SNA was variable, showing increases, decreases or no change. Inhibition of SNA during SAP increase was not secondary to baroreceptor activation as the inhibition persisted in carotid sinus/aortic denervated animals. Although various combinations of changes of SNA and PNA were observed, their temporal courses were similar in many instances. Attenuation of SNA and PNA was synchronized, suggesting that these changes are coupled in the stimulating sites. The findings suggest that some neurons in DM and RVLM act as a functional unit to modulate cardiorespiratory functions whereas others simply coexist in the same area independent from each other.

Differential actions of the medial region of caudal medulla on autonomic nerve activities

1. The inhibitory effects produced by activation of the medial region of caudal medulla on activities of the left and right cardiac sympathetic, vagus and greater splanchnic nerves were studied in chloralose-urethane anaesthetized cats. 2. Electrical stimulation of the medial region produced an 80-92% inhibition of the sympathetic nerve activities, and a 45% and 58% inhibition of the left and right cardiac vagal nerve activities, respectively. There were no significant differences between effects elicited in the left and right autonomic nerves. Similar but smaller inhibitory effects were produced by micro-injection of sodium glutamate (0.5 mol/L) or DL-homocysteic acid (50 mmol/L) to the same medullary sites. 3. These data suggest that neurons residing in the medial medullary region exert strong inhibitory effects on autonomic nerve activities. Since the vasculature is principally innervated by sympathetic nerves, inhibition of sympathetic nerve activities might be the principal factor responsible for the depressor effects caused by activation of the medial region of caudal medulla. The heart is innervated both by sympathetic and parasympathetic nerves. Thus, their simultaneous inhibition during activation of the medial region elicits only a weak and variable inhibition of the heart.

Basic determinants for FM responses in the inferior colliculus of rats

The response of 835 click-sensitive neurons in the inferior colliculus (IC) to ramp frequency modulated (FM) tones was studied in the anaesthetized rat. More than 70% of the cells were sensitive to the FM sound, and over 25% were "FM specialized". Systematic variations of the stimulus parameters showed that sweep velocity, sweep range, and intensity of the FM signal were the 3 basic determinants for the unit response. For an "FM specialized" cell, the response pattern to each of the parameters was either monotonic or bell-shaped. The population statistics of response patterns to the FM parameters, including the tuning factors, were generated. A stimulus domain was proposed to represent the "receptive space" of the FM cells.

Ease of continuous dermal suture removal

The purpose of this investigation is to identify the synthetic nonabsorbable monofilament suture that requires the lowest forces for removal of continuous dermal sutures. Immediately after wound closure, continuous dermal polypropylene sutures require the lowest suture removal forces. The ease of polypropylene suture removal from continuous dermal skin closure is related to the suture's low surface coefficient of friction.

Altered sensitivities of auditory neurons in the rat midbrain following early postnatal exposure to patterned sounds

Pure tone sensitivity of inferior colliculus (IC) neurons in adult rats was studied electrophysiologically following exposure to a frequency-modulated (FM) tone during the first 5 postnatal weeks. The distribution of best frequencies (BF) and minimum thresholds (MT) of 274 single units, when compared to the control, showed an abnormal clustering centered around the region of the audiogram occupied by the FM tone to which the rats had been exposed. This effect was interpreted as the result of activity-dependent changes of IC during development.

Some biomechanical considerations of polytetrafluoroethylene sutures

The biomechanical performance of polytetrafluoroethylene (PTFE) sutures has been compared with that of polypropylene sutures, the standard to which other sutures used in vascular and cardiac surgery are compared. The PTFE is supple and has no plastic memory, while the polypropylene suture is stiff and retains its plastic memory. In addition, the rate of creep encountered in the PTFE suture was significantly less than that of the polypropylene suture. The knotting profiles for knot security for either a square, granny, or surgeon's knot for polypropylene sutures were three throws each. In contrast, knot security with either a square or granny PTFE knot was accomplished with seven throws; six throws were needed for a secure surgeon's knot. The breaking strength of the unknotted and knotted PTFE sutures was approximately one half as great as that for the unknotted and knotted polypropylene sutures. Knot construction significantly reduced the breaking strength of polypropylene sutures but did not alter the breaking strength of PTFE sutures. The percent elongation experienced by both sutures before breakage did not differ significantly. The elasticity, as measured by work recovery, for the polypropylene suture was greater than that for the PTFE suture. On the basis of its unique biomechanical performance characteristics, the PTFE suture should have an important place in vascular and cardiac surgery.

Changes in power spectrum of electromyograms of masseter and anterior temporal muscles during functional appliance therapy in children

This study applied frequency analysis to compare changes in the power spectrum density functions of surface electromyograms obtained from the paired masseter and anterior temporal muscles during therapy with three types of functional appliances, namely the Bionator, modified Fränkel type I, and Fränkel type III. Eighteen children were divided into three groups receiving either Bionator, Fränkel type I, or Fränkel type III therapy; a fourth group consisting of six children who received no therapy served as control. Before and after 3, 6, and 12 months of therapy, each child performed maximum voluntary isometric clenches in the position of maximum intercuspation. The mean frequency of the power spectrum was the variable studied. Children treated with the Bionator and Fränkel type I appliances showed greater changes in mean frequency than those treated with the Fränkel type III appliance. Although the muscles of untreated children also showed shifts of mean frequency to lower frequency values as a function of time, there was a greater downward shift of mean frequency in those treated with functional appliances. The downward shifts might have been associated with changes in muscle fiber lengths and/or recruitment patterns as a result of both treatment and normal growth.

Is there a need for state health department sanitary codes for public hydrotherapy and swimming pools?

The Board of Health of the Commonwealth of Virginia has an outdated sanitary code for its public hydrotherapy and swimming pools. The code is restricted to pools in hotels and other lodging places. The absence of modern regulations for public hydrotherapy and swimming pools has permitted serious deficiencies in pool maintenance, which are highlighted in this report. The most notable of these deficiencies was the presence of high levels of bacterial contamination that could predispose to infect in the water of one public hot tub. The results of this study indicate that the Virginia Board of Health sanitary code for pool water must be revised immediately and should include all public hydrotherapy and swimming pools. Other states and communities may want to assess their codes for swimming pools and hydrotherapy tubs to avoid deficiencies that could be detrimental to public health.

Characterization of expiratory intercostal activity to triangularis sterni in cats

Our purpose was to characterize activity of the intercostal nerve branch innervating the triangularis sterni muscle and the motoneuronal activities comprising this nerve discharge. In decerebrate, vagotomized, paralyzed, and ventilated cats, phasic triangularis sterni neural activity was evident in normocapnia. In most cats, activity did not commence until midexpiration. Activity then rose progressively to terminate at end expiration. Peak neural activities increased in parallel with phrenic activity in hypercapnia and fell in hypocapnia. The progressive increase in triangularis sterni neural activity within each respiratory cycle resulted from recruitment of motoneuronal activities throughout expiration. Once recruited, many motoneurons had a decrementing or constant discharge frequency. In hypercapnia, motoneuronal discharge frequencies increased, and additional activities were recruited. The number of active motoneurons and their discharge frequencies fell in hypocapnia. A similar pattern of motoneuronal activities and responses to stimuli was observed in cats with intact vagi. Factors are considered that may underlie the recruitment pattern of triangularis sterni motoneuronal activities and the inhibition of these in early expiration.

Different respiratory patterns elicited by microinjection of L-glutamic acid into the ventrolateral nucleus of the tractus solitarius in cats

Only limited information relating neurotransmitters to central regulation of the respiratory system exists. L-glutamic acid has been proposed as the primary neurotransmitter in the nucleus of the tractus solitarius (NTS) of cats. To test whether or not glutamic acid has an effect on the respiratory center, we microinjected L-glutamic acid (1 M, 0.1 microliter) via a 1 microliter Hamilton microsyringe into the ventrolateral area of the NTS dorsal respiratory groups (DRG) of unanesthetized, decerebrated cats at two-second intervals with continuous monitoring of tidal volume (VT), respiratory rate (f), end tidal CO2, blood pressure and heart rate. The results showed that glutamate induced the following respiratory changes: VT and f increased; VT and f decreased; and VT decreased but f increased. In addition to VT or f changes elicited by glutamate microinjection, changes in other rhythmic patterns such as apnea, apneusis and irregular respiration were observed. Glutamic acid appears to play a significant role in the modulation of the respiratory drive in the DRG. We, therefore, suggest that the excitatory amino acid L-glutamic acid may be involved in central respiratory control.

Light diffraction intensity from muscle fibres in different osmotic solutions: measurement of equilibration time

A new method for evaluating the osmotic equilibration time of striated muscle fibres is described. Single fibres from the semitendinosus muscles of frog were illuminated normally with a He-Ne laser. The first-order diffraction intensity was measured continuously after the tonicity of the fibre's bathing solution was changed abruptly. Hypertonicity decreased while hypotonicity increased the intensity. The time course of the intensity decrease or increase followed closely a simple exponential with a single time constant. It is proposed that the time constant associated with the diffraction intensity transient is a true representation of the equilibration process. A simple diffraction model provides a relationship between diffraction intensity and the diameter of the muscle fibre. This relationship is used to explain the diffraction intensity of fibres in different osmotic solutions.

EMG power spectrum patterns of anterior temporal and masseter muscles in children and adults

The power spectrum of electromyograms (EMG) has been demonstrated to vary with muscles having different muscle fiber type compositions. This study investigated the variations in EMG power spectrum patterns of the masticatory muscles with age and gender by comparison of the mean power frequency (MPF) of the anterior temporal and masseter muscles in children and adults. Surface EMG signals were sampled bilaterally from the muscles when the subjects were performing maximum voluntary isometric clenches at maximal intercuspal position. The results indicated that MPF values were age-dependent (p less than 0.001), and sexual dimorphism was evident (p less than 0.001), with lower MPF values in male and adult muscles. While male adults had the lowest and female children had the highest MPF values, female adults had MPF values closer to values obtained from male children. These differences or similarities could be attributed to the degree of differentiation of the muscles during growth and development of the craniofacial morphology.

Control of phrenic nerve activity and blood pressure by the medullary raphe nuclei in cats

Electrical and chemical stimulation methods were used to determine the topographic organization of the medullary raphe nuclei (MRN) in controlling the systemic arterial blood pressure (BP) and phrenic nerve activities (PNA). Decerebrated, unanesthetized and bilateral vagotomized cats were used. Effective points in the MRN were systematically explored with constant current stimulation. We found stimulation of the rostral MRN produced a decrease in PNA amplitude and increase in BP and PNA frequency. Stimulation of the caudal MRN produced increases in BP and the amplitude and frequency of PNA. Microinjection of glutamate solution into the caudal or the rostral MRN points produced qualitatively similar results. Thus, we concluded that the caudal MRN neurons had excitatory connections whereas the rostral MRN neurons had excitatory and inhibitory connections to the cardiovascular preganglionic neurons and the phrenic nerve motoneurons.

Serum endorphin levels in uremic patients under maintenance hemodialysis

We checked serum beta-endorphin levels in 17 chronic uremic patients under regular hemodialysis and compared them with the levels in 17 age-matched control subjects. Higher levels of serum beta-endorphin were found in uremic patients (22.54 +/- 6.20 pg/0.1 ml vs 9.42 +/- 5.19 pg/0.1 ml, p less than 0.001). There were no sex differences in both uremic patients (M: F = 21.04 +/- 7.53 pg/0.1 ml vs 23.59 +/- 5.25 pg/0.1 ml, p greater than 0.05) and normal control subjects (9.16 +/- 5.15 pg/0.1 ml vs 9.76 +/- 5.55 pg/0.1 ml, p greater than 0.05). No significant difference in the serum levels was noted between the patients with a hemodialysis history longer than two years (19.96 +/- 5.79 pg/0.1 ml vs 25.45 +/- 5.60 pg/0.1 ml, p greater than 0.05) and those with less than a two year's history (19.96 +/- 5.79 pg/0.1 ml vs 25.45 +/- 5.60 pg/0.1 ml, p greater than 0.05). Moreover, serum beta-endorphin levels were not altered after dialysis (22.54 +/- 6.20 pg/0.1 ml to 20.66 +/- 4.57 pg/0.1 ml, p greater than 0.05) by either acetate or bicarbonate dialysate (acetate vs bicarbonate = 20.83 +/- 5.03 pg/0.1 ml vs 20.13 +/- 3.14 pg/0.1 ml, p greater than 0.05). The role of beta-endorphin in the pathogenesis of uremic syndrome still requires further study.

Automated hydrotherapy pool water treatment system

An automated hydrotherapy water treatment system was described that controls chemical pumps that maintain the pool's water pH and chlorine levels at the designated set points, regardless of the bather load. This system consists of sensing electrodes, a controller, and positive displacement pumps. Because outbreaks of waterborne infections have never been reported in facilities in which the pool water has been continuously maintained at pH 7.2 to 7.8 with a free available chlorine level of at least 1.0 ppm, we recommend that this type of water treatment system be installed in all public pools.

Real-time signal acquisition and analysis for clinical dental electromyography using a microcomputer-based system

The Electromyographic (EMG) Signal Acquisition and Analysis System is an integrated hardware and software system that digitizes multichannels of amplified EMG signals and stores them in user defined disc files before analysis. The software runs on all IBM PC and its compatibles with the appropriate analogue-to-digital (A/D) conversion board. Both time and frequency domain analyses can be computed on-line. This system provides a low cost method of digitizing and analysing EMG signals on real-time for clinical dental electromyography.

Characterization of respiratory-related activity of the facial nerve

Activities of the facial, hypoglossal and phrenic nerves were recorded in decerebrate and paralyzed cats. These animals were ventilated with a servo-respirator which produced lung inflations in parallel with phrenic activity. Peak inspiratory phrenic, hypoglossal and facial activities increased in hypercapnia or hypoxia. When pulmonary inflation was prevented, hypoglossal and facial activities increased more than phrenic. Responses to withholding lung inflation differed from those following vagotomy. These differences were observed in expiratory facial and hypoglossal activities and in hypercapnia- and hypoxia-induced changes in facial activity. Administration of pentobarbital or hyperventilation to hypocapnia caused greater suppressions of hypoglossal than facial activity; the latter declined more than phrenic activity. The results support the hypothesis that influences from the brainstem reticular formation and from pulmonary stretch receptors are differentially distributed to motoneurons innervating upper airway muscles compared to those of the bulbospinal-phrenic system. The concept that ventilatory activity is influenced by tonic, as well as phasic discharge of pulmonary receptors is discussed.