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Biomedical subjects

M H Huang

Publications and source records attributed to M H Huang.

At least 73 records · Page 4Linked to original sources
PubMed1998

Applications of endoscopic surgery in pediatric patients.

Although the advent of endoscopic technology is expanding the fields of reconstructive and aesthetic surgery in adults, there have been few reports of the use of this technology in the pediatric population. Because of their minimally invasive nature, yet wide range of exposure, endoscopic techniques have much appeal for this age group. Here we present our experience with endoscopic pediatric plastic surgery. From February of 1995 to August of 1997, 104 patients underwent 139 procedures utilizing 5- and 10-mm endoscopes. There were 58 male and 46 female patients. The mean age at surgery was 5.6 years (range, 3 weeks to 19 years). The most common type of procedures performed were insertion of tissue expanders (n = 34), excision of benign head and neck masses (n = 27), torticollis release (n = 20), excision of vascular lesions (n = 13), and miscellaneous procedures, (n = 10). There were 26 complications in 139 procedures (19 percent). Seventeen (65 percent) were in the tissue expander group. The rest were scattered among the groups with other diagnoses. Although there did not appear to be a specific type of complication associated with endoscopy, 77 percent occurred in the first 2 months of our study. This suggests a relatively steep technical learning curve. These results demonstrate that endoscopic techniques are eminently applicable in the pediatric population, providing the benefits of small and remote incisional wounds, with complication rates that are comparable with those of conventional open surgical treatment.

Adolescent↗
PubMed1998

Downregulation of endothelin B receptors in cardiomyopathic hamsters.

The mechanisms responsible for abnormal fluid retention in congestive heart failure (CHF) are unclear. Studies were conducted to elucidate how endothelin (ET) may contribute to salt and water retention. Cardiomyopathic (CM) hamsters with moderate heart failure were employed for in vivo and in vitro trials. Clearance methods were used to compare the level of renal function in CM hamsters and control animals. Radioligand binding studies were also performed to determine ET receptor distribution in the inner medullary collecting ducts. CM hamsters exhibited an attenuated response to ANF infusion (FENa: 2.7 +/- 0.5 vs. 5.9 +/- 0.8%, p < 0.01; FEH2O: 1.7 +/- 0.3 vs. 3.2 +/- 0.4%, p < 0.01; UcGMP: 11.2 +/- 2.3 vs. 16.6 +/- 2.0 pmol/min, p < 0.05) and a decrease in total ET receptor density (532 +/- 77 vs. 959 +/- 154 fmol/mg protein, p < 0.005). Particularly ETB receptors were significantly reduced (214 +/- 26 vs. 483 +/- 88 fmol/mg protein, p < 0.003). Enalapril therapy simultaneously restored the natriuretic and diuretic effects of ANF and ET receptor density in the diseased animals. These studies suggest that the renin-angiotensin-aldosterone system and ET hormonal system act together, via ETB receptor downregulation, to promote the abnormal fluid retention observed in CHF.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Smoking-associated mitochondrial DNA mutations and lipid peroxidation in human lung tissues.

To investigate the effect of cigarette smoking on mitochondrial DNA (mtDNA) mutation and lipid peroxidation in lung tissues, 152 samples from lung resections were collected. A novel deletion of 4,839 bp of mtDNA was found in 80 (52.6%) of the 152 lung samples. The breakpoints of the 4,839-bp mtDNA deletion were flanked by a nine-nucleotide direct repeat (5'-CATACACAA-3'). The frequency of occurrence and the proportion of the 4,839-bp mtDNA deletion in the lung increased significantly with the smoking index in terms of pack-years (P < 0.05). The incidence and proportion of the 4,839-bp mtDNA deletion in the lung tissues of current smokers were significantly higher than in those of nonsmokers (P < 0.05). In addition, we found that the content of lipid peroxides in the lung tissues of the smokers was significantly higher than in that of nonsmokers, and increased with the smoking index. The average malondialdehyde level in the lung tissues was 12.81 +/- 4.99 micromol/g for subjects with a smoking index of more than 50 pack-yr, and was 5.39 +/- 0.48 micromol/g for nonsmokers (P < 0.05). Multiple regression analysis showed that the smoking index, tissue lipid-peroxide content, and FEV1/FVC ratio were correlated with the proportion of the 4,839-bp mtDNA deletion in the lung. These results suggest that cigarette smoke plays an important role in the increase in mtDNA mutation and lipid peroxidation in the lung tissues of smokers.

Adult↗
PubMed1998

The differential diagnosis of abnormal head shapes: separating craniosynostosis from positional deformities and normal variants.

The correct differential diagnosis of an abnormal head shape in an infant or a child is vital to the management of this common condition. Establishing the presence of craniosynostosis, which warrants surgical correction, versus non-synostotic causes of head deformity, which do not, is not always straightforward. This paper deals with three groups of abnormal head shape that may cause diagnostic confusion: the spectrum of metopic synostosis; the dolichocephaly of prematurity versus sagittal synostosis; and the differential diagnosis of plagiocephaly. Special emphasis has been placed on the problem of posterior plagiocephaly, in the light of recent evidence demonstrating that lambdoid synostosis has been overdiagnosed. Metopic synostosis presents as a wide spectrum of severity. Although only severe forms of the disorder are corrected surgically, all cases should be monitored for evidence of developmental problems. The dolichocephalic head shape of preterm infants is non-synostotic in origin and is managed nonsurgically. The scaphocephalic head shape resulting from sagittal synostosis requires surgical intervention for correction. Posterior plagiocephaly may be due to unilambdoid synostosis or positional molding, which have very different clinical and imaging features. True lambdoid synostosis is rare. Most cases of posterior plagiocephaly are due to positional molding, which can usually be managed nonsurgically. Regardless of the suture(s) involved, all children with confirmed craniosynostosis should be monitored for increased intracranial pressure and developmental problems.

Bone Diseases↗
PubMed1998

Reflex sympathetic dystrophy syndrome in stroke patients with hemiplegia-three phase bone scintigraphy and clinical characteristics.

In an attempt to investigate the correlation between three phase bone scintigraphy (TPBS) and the clinical manifestation of reflex sympathetic dystrophy syndrome (RSDS) in the upper extremity of hemiplegia, we collected 30 patients with cerebral vascular accidents (CVA) confirmed by head computed tomography (infarction or hemorrhage) within 3 months of their CVA event. All patients received TPBS after admission. Clinical assessment for the development of the RSDS was done at least 3 months (268 +/- 120 days) after the stroke. The correlation between the development of RSD and certain clinical variables (including sex, age, side affected, caused of stroke, and motor stage) were analyzed. Twelve patients (40%) manifested definite or probable RSDS, as assessed by Tepperman's criteria, during the follow-up period. Nineteen patients (63%) exhibited radionuclide evidence of RSDS based on delayed bone scan criteria performed within 3 months (43 +/- 25 days) of the stroke. The positive delayed image of TPBS demonstrated a sensitivity = 92%; specificity = 56%; positive predictive value = 58%, and negative predictive value = 91%. The Kappa statistics for agreement between positive bone scan and RSDS development was 70% (Kappa = 0.43, p < 0.05). Neither sex, age, side affected, cause of stroke, or motor stage had a significant correlation with clinical RSDS. In conclusion, TPBS is a useful screening tool for the development of RSD in hemiplegic patients. However, the diagnosis of RSDS depends on the clinical evaluation and that TPBS as an adjunct assessment of RSDS must be interpreted with caution.

Adult↗
PubMed1998

Lymph node metastasis in squamous cell carcinoma of the intrathoracic esophagus.

BACKGROUND: In esophageal carcinoma lymph node metastasis is one of the most important factors of prognosis. This prospective study evaluated the incidence and extent of lymph node metastasis, and assessed the relationship between the depth of tumor invasion and lymph node metastasis in esophageal carcinoma. METHODS: Between 1985 and 1996, tissue samples from 112 patients undergoing radical esophagectomy and gastric substitution for squamous cell carcinoma of the intrathoracic esophagus were collected. Patients with distant organ metastasis were excluded. All specimens were evaluated and sent for histopathologic examination. RESULTS: In 108 men and four women with a mean age of 63.1 years, the average number of dissected lymph nodes in one surgical procedure, was 30 per person. The most commonly involved nodes were the periesophageal (42.9%) and the perigastric (42.9%) nodes, followed by the recurrent laryngeal nerve (23.8%) and thoracic paratracheal (22.2%) nodes. For tumors in the upper third of the esophagus, the most frequently involved nodal groups were the periesophageal (28.6%) and the paratracheal (28.6%) nodes, followed by the recurrent laryngeal nerve (21.4%) the deep cervical (21.4%), and the perigastric (21.4%) nodes. For tumors in the middle third of the esophagus, the periesophageal nodes (27.3%) were most commonly involved, followed by the perigastric (18.2%) and the subcarina (10.6%) nodes. For tumors in the lower third of the esophagus, the perigastric lymph nodes (37.5%) were the most common nodal metastatic site, followed by the celiac (18.8%) and the recurrent laryngeal nerve (18.2%) nodes. Depth of tumor invasion was also found to correlate significantly with lymph node metastasis (p = 0.0015). CONCLUSIONS: Wide lymph node metastasis between the neck and the upper abdomen occurs frequently in squamous cell carcinoma of the esophagus. For potentially curable esophageal carcinomas, en-bloc esophagectomy with complete locoregional lymph node dissection may provide favorable local control of the lesion and more accurate tumor staging.

Adult↗
PubMed1998

Management of descending necrotizing mediastinitis.

BACKGROUND: Descending necrotizing mediastinitis (DNM) is uncommon, and may be lethal if not treated adequately and promptly. Delayed diagnosis of the disease is sometimes encountered in clinical practice. METHODS: Eight consecutive patients with acute DNM were identified between 1991 and 1995, including five men and three women. The mean age was 45.8 years (range, 22-71 years). The infectious sources consisted of six esophageal perforations, one cervical cutting injury and one tonsillitis. The clinical presentations were evaluated. Diagnostic procedures including chest radiograph, sonogram and computerized tomography scans of the chest and neck were examined. Diagnosis and treatment, including culture results from drained fluids and debrided tissues, and antibiotic and supportive therapies were reviewed. RESULTS: Six patients who underwent aggressive surgical treatment recovered well. Two patients who received supportive treatment died of sepsis alone. The cultured bacteria included: Klebsiella oxytoca, Staphylococcus aureus, Trichosporum and other mixed oral cavity flora. CONCLUSIONS: Early diagnosis and adequate antibiotic and support therapies are essential to achieve good patient outcomes in acute descending mediastinitis. Adequate drainage and debridement, appropriate antibiotic therapy, and sufficient nutritional and respiratory support are the main treatment elements.

Adult↗
PubMed1998

Treatment results of 17 patients with diffuse pleural mesothelioma.

Treatment for diffuse pleural mesothelioma is very difficult. A retrospective study is established for analyzing the experiences in management of such a rare but fatal disease. From May 1960 to August 1996, 17 patients underwent treatment for pathologically confirmed malignant pleural mesothelioma at Veteran General Hospital-Taipei. The chart records were carefully reviewed and surgical specimens were reconfirmed by the pathologist. Single or combined treatment protocols with surgery, chemotherapy, and radiotherapy had been used according to the clinical situation. Pathological staging was recorded according to the Butchart staging system. Gender, smoking, asbestos exposure, histology, and survival were analyzed. There were 17 patients in total, including 15 males and 2 females with a mean age of 62 years. The most common symptoms were chest pain, cough, dyspnea and weight loss. For getting definite pathological diagnosis, the most sensitive procedures were video-assisted thoracic biopsy and open lung biopsy. In spite of trying multiple different treatment protocols, disease staging ( p = 0.0186) and the epithelial pathological type ( p = 0.0353) were the significant prognostic factors in our series. Prognosis of diffuse pleural mesothelioma is very poor. It was predominant in nen and no definite relationship with smoking or asbestos exposure was noted in our series, but it was relatively better in patients with early-stage and epithelial-type disease. Further efforts to improve the survival should be delivered on more aggressive cytoreductive surgery with early postoperative concurrent chemo-radiotherapy.

Adolescent↗
PubMed1998

Intradermal injection of tramadol has local anesthetic effect: a comparison with lidocaine.

BACKGROUND: We observed that intravenous retention of tramadol with a pneumatic tourniquet on the arm inflated to 70 mmHg for one minute could effectively reduce the subsequent propofol injection pain. Tramadol is a central-acting analgesic. The local analgesic effect of tramadol on reducing propofol injection pain is not well known. METHODS: To explore this problem we conducted a double-blind study on intradermal injections of tramadol 25 mg, lidocaine 5 mg and normal saline (all in 0.5 ml volume) which were given to each of the 10 healthy volunteers on the forearm at random. Pain on injections and the degree of local analgesia to pinprick, light touch and cold at each injection site were scored on a 0-4 scale at designated intervals. RESULTS: 5% tramadol, similar to 1% lidocaine, rendered loss of sensation to pin prick, light touch and cold for 30 min after intradermal injection as compared with normal saline (p < 0.01). CONCLUSIONS: We concluded that intradermal injection of tramadol or lidocaine can produce local anesthetic effect.

Adult↗
PubMed1998

Surgery for achalasia: long-term results in operated achalasic patients.

Achalasia is a functional disorder of the alimentary tract due to decreased or absent peristalsis of the esophageal body and obstructive outlet of the esophagus. Surgical treatment, eg. esophagomyotomy of the lower esophageal sphincter (LES), was one choice for resolving the problem and its effect was affirmative from reviews of many internationally authorized articles. However, few reports have ever questioned the long-term effects of it. From January 1968 to May 1996, 159 esophageal achalasic patients, 90 males and 69 females, were admitted due to dysphagia or food regurgitation. One hundred and forty-five patients had received 158 operations related to this benign motor disorder. The majority of patients received either modified Heller esophagomyotomy (M) or M plus modified Belsy Mark IV antireflux procedure (M+W) for primary treatment of their esophageal disorder, while conditional selection with addition of esophageal resection as advanced procedures for failure of primary surgery. We retrospectively studied these patients, collected their preoperative and postoperative clinical results, analyzed the causes of recurrent symptoms, compared the long-term results in different surgical procedures and searched for the pathogenesis of their failure. The results disclosed that the overall success rate for both methods was 73.1% with 85.7% for patients receiving M+W (56) and 64.9% of M (77) only. Through long-term follow-up, we had an improvement rate of 97.4% at an early stage and 53.3% for M at a late stage and 98.4% and 55.6% for M+W, respectively. The postoperative natural course of achalasic patients could be seen and progressive deterioration of the operated patients with time was noted. Several factors might contribute to the causes of unsuccessful surgery. We summarized them as incomplete myotomy, fused or healed myotomy, gastroesophageal reflux (GER), mucosal hernia and co-combined antireflux procedure by hypercalibrated or floppy wrapping. Esophagomyotomy or myotomy plus antireflux procedure for the esophagus could be concluded to rather effective in the long-term but palliative treatments for achalasia chronic deterioration of the results could be found for both of them. Defective myotomy and GER may be the major causes for their failure. The choice of types of surgery between M and M+W was not the cause of the unsuccessful results whereas the operative strategy and procedures would have a certain significance on the long-term effect.

Adolescent↗
PubMed1997

The expression of genes modulating programmed cell death in normal human polymorphonuclear neutrophils.

Normal human polymorphonuclear neutrophils (PMN) have a short life and die in progression via apoptosis. In order to understand the molecular basis of PMN apoptosis, the expression of apoptosis-related (Fas, Fas-ligand, p53, and c-myc) and survival-related (bcl-2) genes was detected by flow cytometry, Western blot and reverse transcription-assisted polymerase chain reaction (RT-PCR). We found that Fas and Fas-ligand (FasL) were expressed on the surface of most of the cells. However, the disappearance of FasL was much faster than Fas after 24 h incubation. p53 and bcl-2 were also expressed in the cytoplasm of most of the cells. In contrast, the expression of c-myc was negligible in PMN. The addition of monoclonal anti-human Fas antibody (25 micrograms/ml) to PMN suspension enhanced whereas anti-FasL antibody (25 micrograms/ml) suppressed PMN apoptosis in 48 h incubation. These results suggest that the activation of Fas pathway induced by Fas-FasL interaction among PMNs is one of the mechanisms for spontaneous PMN apoptosis. Lack of proto-oncoprotein c-myc expression in PMN is responsible for their non-proliferative property and may aggravate the spontaneous apoptosis of the cells.

Animals↗
PubMed1997

Primary pulmonary malignant hemangiopericytoma associated with coagulopathy.

A 34-year-old woman with a massive pulmonary malignant hemangiopericytoma and coagulopathy as a paraneoplastic syndrome is reported. Although coagulopathy may appear as a paraneoplastic syndrome and cause treatment to be more complicated and difficult, it can also be a useful marker to monitor the results of operation and tumor recurrence. This unusual case shows that primary pulmonary malignant hemangiopericytoma deserves aggressive surgical intervention with complete resection even under the circumstances of coagulation abnormality.

Adult↗
PubMed1997

Revisit of primary malignant neoplasms of the trachea: clinical characteristics and survival analysis.

A clinical review with an analysis of prognostic factors, including clinical characteristics, histological classifications, presenting symptoms/signs and treatment modalities, was conducted in 67 patients with primary malignant neoplasms of the trachea who were seen at the Veterans General Hospital-Taipei between 1979 and 1994. The incidence of tracheal cancer was 140 times less than lung cancer during this period. Delayed diagnosis of more than 6 months after onset of symptoms occurred in one-third of the patients owing to lack of specific symptoms/signs indicative of tracheal disease. Epidermoid carcinoma was the most frequent histological type encountered and accounted for half of the cases. Surgical resection was the first choice of treatment for all patients if the disease was locally confined, except for small cell carcinoma and lymphoma. Radiotherapy was given if the patient was not suitable for surgery. Single and multivariate analyses showed that clinical symptoms and signs were not related to prognosis, except for general malaise and acute respiratory failure. Patients suffering from adenoid cystic carcinoma and mucoepidermoid carcinoma had a better prognosis than other histological diagnoses. Whether the patient received radiotherapy or not proved to be a significant prognostic factor in the patients. Patients with tracheal cancers had a poorer prognosis than those with lung cancer.

Adenocarcinoma↗
PubMed1997

Estimated consumption and eating frequency of olestra from savory snacks using menu census data.

Potential chronic (14-d average) and acute (single-day) estimated daily intakes (EDI) were computed for olestra, a fat replacement intended for use in preparing savory snacks. The EDI were computed from eating occasions reported during a 14-d Menu Census survey among 4741 consumers; values were increased by 10% for conservatism. The eating occasions included all meals and in-between meal occasions eaten at home or away. Data from only those individuals who ate savory snacks at least once during the 14 d were used; this included 3820 individuals (81% of the sample) and represented a total of 16,067 eating days (24% frequency). The estimated mean chronic intake ranged from 1.8 to 4.7 g/d, depending on age and gender; at the 90th percentile, the range was 4.1-11.0 g/d. For all ages and both genders, the estimated mean intake was 3.1 g/d. Estimated acute intakes at the mean and 90th percentile ranged from 5.5 to 16.5 g/d and from 10.2 to 24.0 g/d, respectively, depending on age and gender. For all ages and both genders, the estimated mean intake was 10.2 g/d. The lack of parity in the chronic and acute intake estimates indicates that savory snacks are not eaten on a daily basis by the majority of snack eaters. The survey data were analyzed to understand the potential temporal eating patterns of olestra from savory snacks. When snacks were consumed, on average, 69% of the eating occasions were with main meals and 31% were between meals. Savory snacks did not contribute a major fraction of total food to the diet; only 7 and 18% of main meals contained a savory snack food at the 50th and 90th percentile, respectively. For the 50th-percentile consumer (all ages, both genders), savory snacks were eaten four times during the 14-d survey period, and the eating occasions occurred on 3 d. Comparable results for 90th-percentile consumers were 10 eating occasions and 8 eating days.

Adolescent↗
PubMed1997

Endoscopic pediatric plastic surgery.

Although the advent of endoscopic technology is expanding the fields of reconstructive and aesthetic surgery in adults, there have been to date no reports of its use in the pediatric population. Because of its minimally invasive nature, yet wide range of exposure, endoscopic techniques have much appeal in this age group. Herein we present our initial experience with endoscopic pediatric plastic surgery. From February 1995 to December 1995, 41 patients were treated utilizing 5-mm and 10-mm endoscopes at Scottish Rite Children's Medical Center, Atlanta, GA. There were 19 males and 22 females. The mean age at surgery was 5.6 years (range, 7 months-15 years). The most common types of procedures performed were insertion of tissue expanders (N = 19), excision of facial dermoids (N = 7), torticollis release (N = 5), and excision of vascular lesions (N = 4). The remaining 6 patients underwent a variety of reconstructive procedures. The complication rate in the tissue expander group was 3 out of 39 expanders inserted (9.5%), and consisted of infection (N = 2) and rupture (N = 1). In the dermoid group, complications consisted of wound infection requiring reoperation (N = 1), and transient frontal paresis (N = 1). One patient in the hemangioma group had an incomplete resection necessitating open excision. The remaining patients all had satisfactory outcomes with no complications. The majority of the procedures were done on an outpatient basis. These results suggest that endoscopic techniques are eminently applicable in the pediatric population, providing the benefits of small and remote incisional wounds with complication rates that are comparable to those of conventional surgical treatment.

Adolescent↗
PubMed1997

A fresh cadaveric study of the paratubal muscles: implications for eustachian tube function in cleft palate.

The aims of this anatomic investigation were to examine the levator veli palatini, tensor veli palatini, and salpingopharyngeus muscles in relation to normal eustachian tube function and to analyze the clinical implications of these data for tubal physiology in cleft palate individuals. Detailed dissections under 3.2x loupe magnification were conducted on the paratubal muscles of 15 fresh human adult cadaveric head specimens, paying particular attention to their cranial base anatomy. Each half of the cadaveric heads was examined separately, giving a sample size of 30. The cranial base origin of the levator veli palatini was the junction of the cartilaginous and bony parts of the eustachian tube. Contrary to statements in the existing literature, it had no origin from the quadrate area of the petrous temporal bone. In its path toward the velum, it was related inferiorly and lay almost parallel to the tube. The tensor veli palatini originated from the scaphoid fossa of the sphenoid bone and the tube. In contrast to previous descriptions, it was found to consist of a single sheet of muscle with no bilaminar structure. Its axis was oblique to that of the tube. The salpingopharyngeus was a slender muscle attached to the posteroinferior aspect of the pharyngeal end of the tube. It inserted into the palatopharyngeus inferiorly. These morphologic characteristics and anatomic relationships suggest that (1) the levator veli palatini opens the eustachian tube by isotonic contraction that results in displacement of the medial tubal cartilage and the tubal membrane, (2) the tensor veli palatini opens the tube directly by traction on the lateral tubal membrane and indirectly by rotation of the medial tubal cartilage by means of traction on the lateral tubal cartilage, (3) because of its consistently small size, the salpingopharyngeus is probably functionally the least important of the paratubal muscles, (4) the levator veli palatini is unable to cause tubal dilatation in cleft palate because it can only contract isometrically, and (5) tensor veli palatini function is probably unaffected by clefting. However, its mechanism of action may be disrupted iatrogenically by complete hamular fracture or division of its tendon.

Aged↗
PubMed1997

Mandibular odontogenic fibrosarcoma. Case report.

A rare case of mandibular odontogenic fibroma is presented which transformed to a stage 1A odontogenic fibrosarcoma with a local recurrence after surgical resection and unusually delayed pulmonary metastases eight years later. Prolonged follow-up of these patients after complete surgical resection, including regular chest X-rays, is recommended.

Adult↗