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Biomedical subjects

H G Liang

Publications and source records attributed to H G Liang.

9 recordsLinked to original sources
PubMed2000

[Relationship between endogenous active oxygen species, ethylene and the development and operation of the alternative pathway in tobacco callus under salt stress].

This paper reported firstly the dynamic changes of the alternative pathway and the cytochrome pathway in tobacco callus under different concentration of salt. The production rate of endogenous ethylene, the contents of active oxygen species (O2-., .OH and H2O2) and the activities of related enzyme (SOD and CAT) were also investigated simultaneously. The results indicated that the actual operation of the alternative pathway (rho Valt) increased gradually and reached the maxima at 0.75% salt concentration, then declined, while the capacity of the alternative pathway (Valt) didn't exhibit the same change pattern with rho Valt and the cytochrome pathway (rho' Vcyt) changed contrary to rho Valt. At the same time, H2O2 and O2-. accumulated rapidly and reached their peak value at about 0.5% and 0.75% salt concentration respectively, while the content of .OH increased consistently. The production rate of endogenous ethylene increased rapidly and reached its maxima at about 0.5% salt concentration. These data demonstrated that changes of Valt in tobacco callus were associated with a parallel production of H2O2 and endogenous ethylene and a opposite production of .OH, while rho Valt changed parally with the production of O2-.. On the basis of above results, it was deduced that the changes of the development and operation of the alternative pathway in tobacco callus under salt stress might be correlated with the production of endogenous ethylene and the active oxygen species. The possible participation of the alternative pathway in response to salt stress was also discussed.

Cytochromes↗
PubMed1999

Progressive catatonia.

We present the case of a young man with a diagnosis of a childhood-onset pervasive developmental disorder who developed a progressive neurologic deterioration with persistent catatonia and right hemiparesis. On his initial evaluation approximately three years after the onset of mutism, he manifested right hemiparesis and catalepsy. Two years later, although catalepsy had subsided, motor function had deteriorated so that he could not use his hands to feed or dress himself. Oral-facialbuccal dyskinesia manifested by blepharospasm and grimacing were present constantly during waking hours. Quantitative electroencephalography demonstrated markedly decreased amplitude, a finding associated with catatonia. Left sural nerve biopsy indicated large axon cylinder degeneration. Left deltoid biopsy demonstrated perimysial fibrosis and type II fiber predominance. Although magnetic resonance imaging of the head without contrast was normal, positron emission tomography indicated hypometabolism of the right cerebral and the right cerebellar hemispheres. The patient continues to deteriorate despite a course of 25 electroconvulsive treatments. He continues to manifest criteria for catatonia including motoric immobility, mutism, and peculiarities of voluntary movement such as prominent grimacing. We suspect an inherited neurodegenerative disorder. Since catatonia is a treatable condition frequently associated with medical and neurological diseases, examination for the features of catatonia must be included in the assessment of patients with progressive brain degeneration. This report is an attempt to clarify the traits of a serious variant of progressive brain degeneration.

Activities of Daily Living↗
PubMed1993

Traumatic cysts of the spleen--the role of cystectomy and splenic preservation: experience with seven consecutive patients.

Nonparasitic secondary cysts (pseudocysts) of the spleen are uncommon and usually result from blunt abdominal trauma. A 3-year experience with 7 consecutive cases of posttraumatic splenic pseudocysts suggests an increased prevalence of this clinical entity. This report describes 7 adult patients (5 men and 2 women) with a mean age of 32 years, all of whom sustained relatively minor trauma within 5 years of admission. Persistent epigastric or left upper quadrant pain led to a CT scan diagnosis of splenic cysts that varied in size from 7 cm to 15 cm. Each patient underwent resection of the cyst-bearing portion of the spleen with preservation of the remaining normal splenic parenchyma. There were no deaths or complications in the entire group. Because posttraumatic splenic cysts are rare, the accumulation of a significant data base leading to firm conclusions is lacking.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗
PubMed1992

Significant trends in the treatment of hepatic trauma. Experience with 411 injuries.

Several significant advances in the treatment of hepatic injuries have evolved over the past decade. These trends have been incorporated into the overall treatment strategy of hepatic injuries and are reflected in experiences with 411 consecutive patients. Two hundred fifty-eight patients (63%) with minor injuries (grades I to II) were treated by simple suture or hemostatic agents with a mortality rate of 6%. One hundred twenty-eight patients (31%) sustained complex hepatic injuries (grades III to V). One hundred seven patients (83.5%) with grades III or IV injury underwent portal triad occlusion and finger fracture of hepatic parenchyma alone. Seventy-three surviving patients (73%) required portal triad occlusion, with ischemia times varying from 10 to 75 minutes (mean, 30 minutes). The mortality rate in this group was 6.5% (seven patients) and was accompanied by a morbidity rate of 15%. Fourteen patients (11%) with grade V injury (retrohepatic cava or hepatic veins) were managed by prolonged protal triad occlusion (mean cross-clamp time, 46 minutes) and extensive finger fracture to the site of injury. In four of these patients an atrial caval shunt was additionally used. Two of these patients survived, whereas six of the 10 patients managed without a shunt survived, for an overall mortality rate of 43%. Over the past 4 years, six patients (4.7%) with ongoing coagulopathies were managed by packing and planned re-exploration, with four patients (67%) surviving and one (25%) developing an intra-abdominal abscess. One additional patient (0.8%) was managed by resectional debridement alone and survived. During the past 5 years, 25 hemodynamically stable and alert adult patients (6%) sustaining blunt trauma were evaluated by computed tomography scan and found to have grade I to III injuries. All were managed nonoperatively with uniform success. The combination of portal triad occlusion (up to 75 minutes), finger fracture technique, and the use of a viable omental pack is a safe, reliable, and effective method of managing complex hepatic injuries (grade III to IV). Juxtahepatic venous injuries continue to carry a prohibitive mortality rate, but nonshunting approaches seem to result in the lowest cumulative mortality rate. Packing and planned reexploration has a definitive life-saving role when used adjunctively in the presence of a coagulopathy. Nonoperative management of select hemodynamically stable adult patients, identified by serial computed tomography scans after sustaining blunt trauma is highly successful (95-97%).

Adult↗
PubMed1992

[A comparative study on the metabolism of nucleic acids during the subculture and differentiation of tobacco callus].

Changes in the contents of DNA and RNA, RNA species, the synthesis rates of DNA and RNA, and the activity of DNase and RNase were investigated in the callus of tobacco (Nicotiana tabacum L. cv. Willow Leaf) during subculture and differentiation. The contents of DNA and RNA were higher in differentiating callus than that in subcultured callus. After day 12, the contents of DNA and RNA in differentiating callus rose continuously while the contents of DNA and RNA in subcultured callus remained constant. Changes in RNA species and its relationship to total RNA level were also analyzed. At the stage of shoot primordium formation in differentiating callus, the activity of RNase increased markedly and the synthesis rate of RNA increased continuously; while the RNase activity and the synthesis rate of RNA in subcultured callus were much lower during the same period. During the period of shoot growth, the synthesis rate of DNA in differentiating callus was elevated compared to that in subcultured callus. The results above suggested that the metabolism of nucleic acids in differentiating callus was more active than that in subcultured callus.

Culture Techniques↗
PubMed1990

Experience with selective operative and nonoperative treatment of splenic injuries in 193 patients.

During the past decade splenic salvage procedures rather than splenectomy have been considered the preferred treatment for traumatic splenic injuries. Splenic preservation has been most often accomplished by splenorrhaphy and more recently by a controversial nonoperative approach. This report delineates indications, contraindications, and results with splenectomy, splenorrhaphy, and nonoperative treatment based on an 11-year experience (1978 to 1989) in which 193 consecutive adult patients with splenic injuries were treated. One hundred sixty-seven patients (86.5%) underwent urgent operation. Of these, 111 (66%) were treated by splenorrhaphy or partial splenectomy and 56 (34%) were treated by splenectomy. During the last 4 years, 26 additional patients (13.5%) were managed without operation. Patients considered for nonoperative treatment were alert, hemodynamically stable with computed tomographic evidence of isolated grades I to III splenic injuries. Overall 24% of the injuries resulted from penetrating trauma, whereas 76% of the patients sustained blunt injuries. Complications were rare, with two patients in the splenorrhaphy group experiencing re-bleeding (1.8%) and one patient (4%) failing nonoperative treatment. The mortality rate for the entire group was 4%. This report documents that splenorrhaphy can safely be performed in 65% to 75% of splenic injuries. Splenectomy is indicated for more extensive injuries or when patients are hemodynamically unstable in the presence of life-threatening injuries. Nonoperative therapy can be accomplished safely in a small select group (15% to 20%), with a success rate of nearly 90% if strict criteria for selection are met.

Adult↗
PubMed1984

A Comparative Study of CN-Resistant Respiration in Different Cultures of Tobacco Callus.

The callus of Nicotiana rustica cv Gansu yellow flower and N. tabacum cv willow leaf were cultured on ordinary subculture medium (M-1) and on regeneration medium (M-2), respectively. No differentiation was observed in Gansu yellow flower tobacco callus cultures grown on both M-1 and M-2 medium. The respiration of both cultures was partially resistant to cyanide and markedly inhibited by m-chlorobenzhydroxamic acid. The relative contributions of alternative and cytochrome pathway were 31% and 47% of the total respiration, respectively, in M-1 callus cultures. The relative O(2) uptake of the two pathways was not changed significantly in M-2 callus cultures. In subcultured M-1 callus cultures of Willow leaf tobacco, the respiration mediated via alternative pathway was about 29 to 38% of the total respiration, and the cytochrome pathway still was the major respiratory pathway. In M-2 callus cultures in which differentiation occurred, the relative contribution of alternative pathway increased to 41 to 47% of the total respiration, and the cytochrome pathway decreased considerably. These results suggested that the change of respiratory electron transport pathway was probably related to the differentiation of tobacco callus cultures.

Journal Article↗
PubMedDate not supplied

Minimizing emergence phenomena: subdissociative dosage of ketamine in balanced surgical anesthesia.

Three hundred twelve patients, ranging in age from 14 to 89 years and undergoing various major and minor surgical procedures, were anesthetized by oxygen, nitrous oxide, and ketamine in sequence. Anesthesia was induced with thiopental (5.8 mg./kg.). The first 212 patients received an initial dose of ketamine of 1.6 mg./kg. lean body mass; 100 other patients, an initial (subdissociative) dose of ketamine of 0.4 mg./kg. body weight. Subsequent doses of ketamine, one-half the initial dose, were given 20 to 40 minutes apart, as needed. Postoperative subjective reactions were limited to slight confusion on emergence, with some disorientation to time, and occurred in 10 patients (5 percent) in the first group and 4 (4 percent) in the latter group. No psychotomimetic reactions were noted in either group. The latter group unanimously found the anesthetic technic acceptable for future use.

Adolescent↗