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Biomedical subjects

M Y Lin

Publications and source records attributed to M Y Lin.

At least 19 recordsLinked to original sources
PubMed1999

Morphine tolerance in arthritic rats and serotonergic system.

To understand whether chronic inflammation alters the development of morphine tolerance, the tail-flick test was used to evaluate the analgesic effect of morphine (75 mg tablet, s.c.) in the arthritic rats at the day 9-12 after the inoculation with Freund's adjuvant. Spinal cord monoamines and amino acid neurotransmitters were concomitantly measured. Chronic inflammation attenuated the antinociceptive effect of morphine as tolerance developed faster in the arthritic rats compared to the vehicle-treated controls. In addition, ratio of 5-hydroxyindole-3-acetic acid/5-hydroxytryptamine (5-HIAA/5-HT) increased in the lumbar spinal cord of arthritic rats without any change in the concentrations of norepinephrine, glutamate, aspartate or GABA. Interestingly, increased serotonin turnover in the spinal cord was observed in both control and arthritic rats 24 hours after morphine treatment. Overall, the results suggest a significant role of serotonin up-regulation in the spinal cord during chronic pain and the development of morphine tolerance.

Analgesics, Opioid↗
PubMed1998

Stability and diversity of T cell receptor repertoire usage during lymphocytic choriomeningitis virus infection of mice.

Numerous studies have examined T cell receptor (TCR) usage of selected virus-specific T cell clones, yet little information is available regarding the stability and diversity of TCR repertoire usage during viral infections. Here, we analyzed the Vbeta8.1 TCR repertoire directly ex vivo by complementarity-determining region 3 (CDR3) length spectratyping throughout the acute lymphocytic choriomeningitis virus (LCMV) infection, into memory, and under conditions of T cell clonal exhaustion. The Vbeta8 population represented 30-35% of the LCMV-induced CD8(+) T cells and included T cells recognizing several LCMV-encoded peptides, allowing for a comprehensive study of a multiclonal T cell response against a complex antigen. Genetically identical mice generated remarkably different T cell responses, as reflected by different spectratypes and different TCR sequences in same sized spectratype bands; however, a conserved CDR3 motif was found within some same sized bands. This indicated that meaningful studies on the evolution of the T cell repertoire required longitudinal studies within individual mice. Such longitudinal studies with peripheral blood lymphocyte samples showed that (a) the virus-induced T cell repertoire changes little during the apoptosis period after clearance of the viral antigens; (b) the LCMV infection dramatically skews the host T cell repertoire in the memory state; and (c) continuous selection of the T cell repertoire occurs under conditions of persistent infections.

Animals↗
PubMed1998

Differential surface accessibility of alpha(187-199) in the Torpedo acetylcholine receptor alpha subunits.

We have probed the surface accessibility of residues alpha187 to alpha199 of the Torpedo acetylcholine receptor with monoclonal antibody 383C, which binds uniquely to these residues. However, 383C binds to only one of the two alpha subunits in the membrane-bound receptor, neither of the two subunits in carbamylcholine-desensitized receptor, and to both alpha subunits in Triton X-100 solubilized receptor. The kinetics of association and dissoci-ation of 383C with the peptide alpha(183-199) compared to those with the membrane-bound receptor suggest that all but a single hydrogen bond of affinity derives from contacts between this peptide and the monoclonal antibody paratope. Inhibition of 383C binding by alpha-bungarotoxin selectively directed to the alpha subunit correlated with the high-affinity d-tubocurarine binding site, along with a lack of inhibition by alpha-bungarotoxin directed to the alpha subunit correlated with the low-affinity d-tubocurarine binding site, suggests that the 383C epitope on the membrane-bound receptor resides on the alpha subunit associated with the high-affinity d-tubocurarine binding site. The results presented here suggest a structural basis for the differences between the two receptor acetylcholine binding sites.

Animals↗
PubMed1998

Management of lactose maldigestion by consuming milk containing lactobacilli.

The influence of nonfermented milk containing L. acidophilus or L. bulgaricus on lactose utilization by lactose maldigesters was investigated. Nonfermented milks containing L. acidophilus or L. bulgaricus at 10(8) and 10(9) CFU/ml were prepared using 2% low-fat milk. Lactose maldigestion was monitored by measuring breath hydrogen at hourly intervals for 8 hr following consumption of 400 ml of each diet. Nonfermented milk containing L. acidophilus B at 10(8) CFU/ml were not effective in reducing breath hydrogen and symptoms. Nonfermented milk containing L. acidophilus B at 10(9) CFU/ml only slightly decreased breath hydrogen production; however, the symptoms were significantly improved. Nonfermented milks containing L. bulgaricus 449 at 10(8) and 10(9) CFU/ml were effective in reducing breath hydrogen and symptoms. The results for bulgaricus milk were all significant. In this study, L. acidophilus B and L. bulgaricus 449 were chosen because of their similar beta-galactosidase activity and bile sensitivity. L. acidophilus and L. bulgaricus are both thermophilic lactobacilli and an active transport (permease) system is found in both species for lactose transport. The major factor affecting in vivo lactose digestion in this study appears to be the bacterial cell wall/membrane structures. That the cell wall/membrane structures of L. acidophilus are different from those of L. bulgaricus can be indirectly proven by the results of sonication time for maximum beta-galactosidase activity measurement. The results of this study indicate that L. bulgaricus is usually a better choice than L. acidophilus for manufacturing nonfermented milks for lactose maldigesters.

Animals↗
PubMed1997

Surgical treatment of pediatric lung abscess.

Eight pediatric patients with lung abscesses underwent surgical intervention in our hospital during a 7-year period. All the abscesses were associated with severe sepsis or complicated by a bronchopleural fistula that did not respond to medical treatment and tube thoracostomy. Seven patients required unilateral thoracotomies, and one patient with bilateral lesions required simultaneous bilateral thoracotomies. One tension pneumatocele required a preceding pneumonostomy. All patients underwent decortication and at least one additional surgical procedure consisting of: lung debridement plus bronchial closure (n = 4); lobectomy (n = 2); bisegmentectomy (n = 3); and/or segmentectomy (n = 1). There were no operative deaths, but two patients had persistent air leakage that was treated by bronchial closure. The average hospital stay was 22 days (postoperative 10.1 days). All the patients recovered completely. For many pediatric lung abscesses that do not respond to medical treatment and simple drainage procedures, surgical intervention is indicated and can shorten the hospital stay.

Bronchial Fistula↗
PubMed1997

Surgical results of 23 patients with tracheobronchial injuries.

The objective of this study was to evaluate the surgical results of tracheobronchial injuries. Between July 1988 and March 1996, tracheobronchial surgery was performed on 23 injured patients. According to the aetiology, the injuries were categorized as blunt injury (n = 13), cutting or penetrating injury (n = 5), and corrosive injury (n = 5). Blunt injuries included three complete laryngotracheal disruptions, one tracheal laceration, and eight bronchial ruptures. Cutting or penetration injuries included four laryngotracheal ruptures and one tracheal cutting wound. Corrosive injuries included one tracheal necrosis, one tracheal stenosis and three esophagorespiratory fistulae. Operative procedures that were performed on the tracheobronchus included tracheoplasty (n = 12), bronchoplasty (n = 7), sleeve resection of the trachea (n = 2) and bronchus (n = 2). Two hospital deaths were encountered, with a mortality rate of 8.7%. One patient with caustic injury died of bronchopleural fistula and empyema. The other patient died with multiple injuries from multiple organ failure which was unrelated to the bronchoplasty. One postoperative complication was restenosis of the trachea in a caustic injured patient, which was treated by a T-tube insertion. In conclusion, tracheobronchoplasty is an effective life-saving emergency procedure for the patients with tracheobronchial injuries.

Adult↗
PubMed1997

Surgical results of 29 patients with benign tracheobronchial lesions.

This study was carried out in order to evaluate the surgical results of benign tracheobronchial diseases. Between July 1988 and March 1996, tracheobronchial surgery was performed on 29 patients with a variety of benign diseases. The primary diseases were post intubation or post tracheostomy tracheal stenosis (n = 12), tuberculous stenosis (n = 7), congenital tracheal stenosis with or without vascular ring (n = 4), tracheobronchial tumour (n = 2), oesophageal tumour (n = 1), and miscellaneous conditions (n = 3). Thirty-one operative procedures included sleeve lobectomy (n = 7), sleeve resection of trachea (n = 17) and bronchus (n = 2), and plastic surgery of trachea (n = 4) and bronchus (n = 1). There was one operative death, which put the mortality rate at 3.4%. There were five postoperative complications in this series (17.2%), including anastomotic disruption of trachea (n = 1), bilateral vocal cord palsy (n = 1), prolonged endotracheal intubation (n = 1) and overgrowth of granulation (n = 2). The complication of anastomotic disruption of trachea was treated by insertion of a tracheal T-tube, and the granulation was treated by bronchoscopic excision. We suggest that tracheobronchoplasty is a safe procedure in carefully selected patients with benign diseases.

Adolescent↗
PubMed1997

Surgical results of 40 patients with malignant tracheobronchial lesions.

The objective of this study was to evaluate the results of tracheobronchoplastyperformed on a variety of malignant diseases which involved the tracheobronchus. Between July 1988 and March 1996 tracheobronchial surgery was performed on 40 patients who had a variety of malignant diseases. The primary diseases were bronchogenic carcinoma (n=26), tracheobronchial tumour (n=5), thyroid cancer (n=6), and oesophageal cancer (n=3). Operative procedures that were performed on the tracheobronchus were sleeve lobectomy (n=22) or bilobectomies (n=5), sleeve pneumonectomy (n=3), sleeve resection of trachea (n=7) and bronchus (n=3). There was one postoperative death with a mortality rate of 2.5%. However, there were no significant postoperative complications apart from the one postoperative death; one patient developed a bronchopleural fistula and empyema. In lung cancer patients, the 2 year survival rate was 47.3%, and one (3.8%) local tumour recurrence. Four of five patients who had tracheobronchial tumours were alive and free from disease during 2-6 year follow-up period. One patient who had malignant fibrous histiocytoma died of brain metastasis 6 months after the operation. Among six patients whose thyroid cancer involved the trachea, one patient survived for 7 years, the other five patients were still alive and free from disease 2-5 years after the operation. Of the three patients whose oesophageal carcinoma involved the tracheobronchus, there was one operative death and the others died of tumour recurrence 1 and 2 years, respectively. We suggest that tracheobronchoplasty is a safe procedure with low morbidity and mortality rates in carefully selected patients with malignant diseases.

Adolescent↗
PubMed1997

Alpha beta and gamma delta T-cell networks and their roles in natural resistance to viral infections.

Both alpha beta and gamma delta T-cell populations and natural killer (NK) cells include cytotoxic, interferon (IFN)-gamma-producing lymphocytes that actively respond to viral infections. We show here that all three populations can provide "natural resistance" to viruses very early in infection and describe how the T-cell populations are modulated to provide this function. gamma delta T cells were shown to play a role in controlling vaccinia virus (VV) infections, as VV grew to much higher titers in gamma delta T-cell knockout mice than in normal mice 3-4 days post-infection. Our studies of the alpha beta T-cell responses to viruses revealed an interactive network of T cells that is modulated substantially during systemic infections. There is an induction phase associated with a massive virus-specific CD8 T-cell response, an apoptosis phase during which the T cells become sensitized to activation-induced cell death (AICD), a silencing phase, during which the T-cell number and activation state is reduced, and, finally, a memory phase associated with the very stable preservation of virus-specific memory cytotoxic T-lymphocyte precursors (pCTL). Infection of mice immune to one virus with a heterologous virus leads to a selective expansion of memory CTL cross-reacting between the two viruses, but, after homeostasis is again established, there is a quantitative reduction and qualitative alteration of memory to the first virus. Our results suggest that memory alpha beta T cells cross-reactive between heterologous viruses mediate both immunopathology and protective immunity at early stages of the second virus infection. Thus, memory alpha beta T cells can, like gamma delta T cells and NK cells, provide natural immunity to viral infections.

Animals↗
PubMed1996

Construction of an integrative food-grade cloning vector for Lactobacillus acidophilus.

An integrative cloning vector was constructed using a randomly cloned HindIII-digested chromosomal fragment from Lactobacillus acidophilus ADH inserted into an Escherichia coli vector, pBluescript II SK+. Southern hybridization studies demonstrated homology of the inserted fragment with one other L. acidophilus strain and one Bifidobacterium strain. Identification of a SauI site located near the middle of the 1.9-kb ADH chromosomal fragment made it possible to clone the Lactobacillus bulgaricus beta-galactosidase (EC 3.2.1.23) gene into this vector. The vector was unable to replicate in the homologous host, L. acidophilus ADH, following electroporation. The chromosomal fragment allowed the integration of the beta-galactosidase gene (beta gal) into the host chromosome via homologous recombination. The size of the two flanking L. acidophilus ADH chromosomal fragments, approximately 0.95 kb each, was sufficient to allow the double cross-over to take place. Southern hybridization demonstrated that only L. acidophilus and L. bulgaricus DNA had been integrated into the chromosome of the host strain. The beta-galactosidase activity of the transformant was increased approximately 200-fold when compared to the enzyme activity of the wild-type strain. The beta gal gene remained stable in the transformant strain after 30 transfers in growth media without selection pressure. This first-generation integrative cloning vector is constructed solely of DNA from organisms consumed by humans and could be considered a food-grade vector system.

Bacterial Proteins↗
PubMed1996

Results of surgical treatment of 107 patients with complications of pulmonary tuberculosis.

The objective of this study was to evaluate the results of surgical intervention performed on 107 patients with pulmonary tuberculosis complications. Between September 1988 and December 1995, 107 patients underwent a total of 126 operations for major complications of pulmonary tuberculosis. One hundred and twenty-six operations consisted of lobectomies only or plus other lung resections performed in 55 cases, pneumonectomies in 20 cases, segmentectomies in 18 cases, wedge resections in two cases, tracheobronchoplasties in four cases, decortications in two cases, cavernostomies with concomitant muscle transpositions in seven cases, thoracoplasties reserved for the previously failed operations or to be a supplement for pulmonary resections in 18 cases. The operative mortality rate was of 1.8%, and the major complication rate was of 16.8%. Twenty-eight (26.1%) patients with tuberculosis bacilli in sputum before operation have converted except one diabetic patient. In conclusion, surgery is indicated in pulmonary tuberculosis complications that are life-threatening or unresponsive to chemotherapy. Pulmonary resection is the procedure of choice for most cases that require surgery.

Adolescent↗
PubMed1996

Functional evaluation of esophageal substitutes.

BACKGROUND: The function of esophageal Substitutes is not comparable to the normal esophagus. METHODS: To clarify the difference between esophageal substitutes and the normal esophagus, radionuclide scintigraphy and clinical assessment were used as study methods. The study was conducted in groups of substernal colon (n = 9), substernal ileocolon (n = 6), posterior mediastinal colon (n = 6) and posterior mediastinal gastric tube (n = 14). The control group consisted of normal volunteers (n = 8). RESULTS: Patients with substernal ileocolon did not experience nocturnal regurgitation, which occurred often in other groups. All esophageal substitutes had a decreased clearance ability compared to the normal esophagus. Among these substitutes, the posterior mediastinal gastric tube had the shortest swallowing time, while the substernal ileocolon had the longest. The substernal colon had a significantly prolonged transit time. Among these study groups, neither differences of clearance ability nor those of alimentary reflux reached statistical significance. CONCLUSIONS: From the view point of food transit, it is suggested that a posterior mediastinal gastric tube or posterior mediastinal colon is the first choice of esophageal substitute.

Adult↗
PubMed1995

Bronchial rupture caused by blunt chest injury.

We have surgically treated six patients with bronchial rupture caused by blunt chest injury in the past 5 years. All injuries resulted from traffic accidents, except in one patient who was hit by a crane. Clinical manifestations included chest pain (n = 6), subcutaneous emphysema (n = 4), and dyspnea (n = 6). Roentgenographic findings were tension (n = 3) or nontension (n = 3) pneumothorax, subcutaneous emphysema (n = 4), pneumomediastinum (n = 3), deep cervical emphysema (n = 5), and delayed collapse of the affected lung (n = 3). Three patients had associated injuries: right clavicle and rib fractures in the first; right humeral, scapular, and multiple rib fractures and left sternoclavicular joint dislocation in the second; and left clavicle fracture in the third. These six patients all underwent immediate tube thoracostomy and then bronchoplasty. Bronchoplasty was performed within 3 days in four patients and on days 16 and 30, respectively, in the other two patients. The affected lung demonstrated full expansion in all patients immediately after bronchoplasty. Follow-up bronchoscopy showed good patency of all bronchi.

Accidents, Traffic↗