Search PubMed⌕ Search

Biomedical subjects

Y D Gu

Publications and source records attributed to Y D Gu.

At least 19 recordsLinked to original sources
PubMed2001

Phrenic nerve conduction study in patients with traumatic brachial plexus palsy.

Phrenic nerve conduction studies were performed to assess the ipsilateral nerve in 100 patients with traumatic brachial plexus palsy. Open exploration and intraoperative recordings of somatosensory evoked potentials and nerve action potentials were used to confirm the level of root lesions. The relationship between C-5 preganglionic root lesion and the functional integrity of the ipsilateral phrenic nerve was examined. The phrenic nerves were normal in 80 cases, partially injured in 7, and severely injured in 13. We found C-5 preganglionic root lesions in 13 (100%) patients with severely injured, 5 (71.4%) with partially injured, and 24 (30%) with normal phrenic nerves. This correlation suggests phrenic nerve conduction study is a useful tool in the diagnosis of C-5 preganglionic root lesions in patients with traumatic brachial plexopathy.

Adolescent↗
PubMed2001

Lowest number of brachial plexus nerve roots required for maintaining normal limb function--an experimental study.

Rat models with different division of nerve roots of the brachial plexus were designed to assess whether single or two nerve roots of the contralateral normal brachial plexus can be divided as donor nerves in treatment of brachial plexus root avulsion. Two hundred and fifty-two SD rats were randomly divided into 13 groups, i.e. five groups with single nerve root division, seven groups with two nerve roots division, and one group with three nerve roots division. Post-operative evaluation by electroneurophysiology and muscular histology was performed at two weeks and two months. Results showed that in groups with single nerve root division, the experimental limb function did not show an apparent damage; in groups with non-neighbouring two nerve roots cutting, it did show a harmful repercussions on the limb at two weeks, but most of them recovered to normal at two months; in groups with neighbouring two nerve roots division and with non-neighbouring three nerve root cutting, the limb function showed a persistent damage. In conclusion, division of nerve root alone or even non- neighbouring two nerve roots of the brachial plexus did not affect the forelimb function of the rat permanently.

Animals↗
PubMed2001

[Culture of human muscle satellite cell].

OBJECTIVE: To investigate the biological characteristics of human muscle satellite cell cultured in vitro. METHODS: Human muscle satellite cells were obtained from skeletal muscle biopsies of six patients during corrective orthopedic surgery, cultivated in growth medium for ten days, then in differentiation medium for additional five days. Human satellite cells were identified with monoclonal antibody against desmin. Cells were observed under phase contrast microscopy. RESULTS: Human muscle satellite cells proliferated in growth medium, and fused to form myotubes in differentiation medium. After 24 hours in differentiation medium, the confluent satellite cells began to fuse actively and achieved the top level at 72 hours. CONCLUSION: Human muscle satellite cell can proliferate and differentiate in appropriate culture condition. Immunocytochemical detection of desmin is the effective early method to determine satellite cell.

Adolescent↗
PubMed2000

Fibrillation potential amplitude to quantitatively assess denervation muscle atrophy.

Denervated muscle fibers exhibit spontaneous, repetitive single muscle fiber discharges and display fibrillation potentials detectable by electromyography. To explore the changing pattern of fibrillation potential amplitude after peripheral nerve injury and its relationship to the degree of muscle atrophy, fibrillation potential amplitudes were recorded on completely denervated biceps brachii of 173 patients with brachial plexus injury. Biceps brachii biopsies were taken at the same sites as the electromyogram recordings in 63 patients. The biopsies were analyzed by ATPase staining and the cross-sectional areas of fast and slow-twitch fibers were calculated. We found that the fibrillation potential amplitude and the cross-sectional areas of denervated muscle decay over time (P < 0.05), and both correlate negatively with denervation time (P < 0.01-0.05) within the first 15 months. The fibrillation potential amplitude correlates positively with both type I and II fiber cross-sectional areas (P < 0.0005-0.01). Our results show that fibrillation potential amplitude is closely correlated with muscle fiber size during the first 15 months after nerve injury, and it may therefore serve as a convenient index to evaluate quantitatively the degree of atrophy of denervated muscles. Electromyographic studies thus may help in designing treatment strategies.

Adolescent↗
PubMed2000

Vascular anatomic variations in second toe transfers.

To devise a new classification of vascular variations in second toe transfer we analyzed the anatomic details of the first dorsal metatarsal artery in 304 cases of second toe transplantation and the venous structure in 200 cases. According to location, the arterial vascularity was classified as superficial (18% of cases), intramuscular (54%), inframuscular (23%), and absent (5%). According to diameter, it was classified into large (16%), medium (64%), and small (20%). Based on branching pattern, the artery was classified into ramifying type (88%), main trunk (4%), and fine branch type (8%). The venous drainage of the second toe was categorized as greater saphenous vein main trunk type, greater saphenous vein fine branch type, dorsal digital vein main trunk type, and dorsal digital vein fine branch type. Variations of the first dorsal metatarsal artery are common. Classification should be done according to its location, diameter, and branching pattern at the toe web. Regardless of location, big vessels entering the second toe are the most important attribute for successful outcome.

Adolescent↗
PubMed2000

Classification of impairment of shoulder abduction in obstetric brachial plexus palsy and its clinical significance.

Shoulder abduction was studied in 25 cases of obstetric brachial plexus palsy (OBPP). According to muscle function, electromyographic features and X-ray examination, impairment of shoulder abduction could be classified into dynamic, resistant or combined types. Five cases were the dynamic type, which was characterized by paralysis of the shoulder abductors. Fifteen cases were categorized as the resistant type, with contracture of the subscapularis muscle, co-contraction of latissimus dorsi and teres major muscles and secondary disorders of the shoulder joint. Five cases were classified as the combined type in which there were both dynamic and resistant factors. Appropriate management and surgical procedures in the shoulder affected by OBPP depend on the pathological classification.

Adolescent↗
PubMed2000

The donor foot in free toe or joint transfers.

Eighty-four cases of free second toe, multiple toe or second metatarsophalangeal joint transfers were studied by case review and follow-up. The function of the donor foot had recovered completely within 6 months in 89% of patients. The wounds on the donor foot healed in 2-3 weeks in 90% of patients. Slight numbness on the dorsal aspect of the donor foot, intolerance to cold, mild reduction in push-off, scar tenderness and pain or swelling occurred in only a few patients and generally were not considered of significance. Multiple toe transfers created more donor problems in terms of healing and appearance. Some foot deformities with plantar callosities were observed at long term review. However, all patients were capable of work and normal activities.

Adult↗
PubMed2000

[Experimental study of mechanism and measures of prevention and treatment of hypothermal vasoconstriction].

OBJECTIVE: To investigate the mechanism and to explore the measures of prevention and treatment of hypothermal vasoconstriction. METHODS: By the techniques of endothelial cell culture and scanning electron microscopy, and vasomotor functional test of isolated vascular vessels, the relation of hypothermal vasoconstriction and the release of endothelium-derived contractile and vasodilative factors were observed. RESULTS: Hypothermia obviously induced vasoconstriction of isolated vascular vessels, whether endothelium was intact or removed, the lower the temperature, the higher the vascular tension. Removal of endothelium could decrease the effect of vasoconstriction by hypothermia. The conditioned medium of bovine aortic endothelial cell could induce significantly vasoconstriction of isolated rat common neck arterial ring in hypothermia. It indicated that the bovine aortic endothelial cells secreted contractile factors into the medium. Reheating to 37 degrees C or vasodilator or reheating plus vasodilator did not obviously influence the hypothermia-induced vasoconstriction within 2 hours. When reheating to 50 degrees C, vascular tension was decreased, but only changed in range of 28% to 42%. CONCLUSION: Hypothermia vasoconstriction is relative to vasoconstrictor factors secreted by endothelium. Reheating to 37 degrees C or vasodilator does not antagonize the constriction of vascular vessels. Reheating to 50 degrees C only partially eliminates the constrict effect of blood vessels, so the prevention of hypothermia vasoconstriction should be emphasized.

Animals↗
PubMed2000

[Experimental evaluation of low-dose aspirin used in microvascular surgery].

OBJECTIVE: To evaluate the effect of low-dose aspirin on the deposition of platelet at the anastomotic site and the function of coagulation system in order to provide experimental data for clinical use. METHODS: (1) Twenty-eight SD rats were divided into experimental group (n = 21) and control group (n = 7), aspirin were administered through a catheter placed in the femoral vein in dose of 4 mg/kg in the experimental group and the same dose of normal saline in the control group. The experimental group was subdivided into 3 groups, with 7 rats in each group, according to survival time of 24, 48 and 72 hours after dose. Samples of 4 ml blood were taken by heart puncture from each rat to investigate the maximal platelet aggregation rate(MAR), prothrombin time(PT) and kaolin partial thromboplastin time(KPTT). (2) Sixteen New Zealand White rabbits were divided into experimental and control group, 8 rabbits in each group. Drugs were given in the same way. Forty-eight hours later, the bilateral femoral arteries of each rabbit were exposed and arteries between inguinal ligament and the origin of the superficial epigastric arteries were transected and end-to-end anastomosis was completed with interrupted suturing technique. Fifteen and 120 minutes after the recovery of blood flow, the left and the right vessels containing anastomotic sites were harvested respectively and treated with 125I-labeled anti-GP IIb/III a antibody (SZ-21) using radioimmunobinding method. The radioactivities of the anastomosed vessels were measured. RESULTS: The KPTT in the experimental group was longer than that of the control group at 24- and 48-hour group, the mean percentages of increase were 42.56% and 35.33% respectively, and there were very significant differences between the experimental and control group in 24-hour group (P < 0.001). The PT value in experimental group was longer than that of the control group, but there was no significant difference (P > 0.05), and the maximal aggregation rate of platelet in the experimental group was significantly lower than that of the control group after 72 hours (P < 0.001). The radioactivity of the anastomosed arteries in the experimental group were significantly higher than that of the control group (P < 0.001) at 15 minutes after the recovery of blood flow, the mean percentage of increase was 110%. CONCLUSION: Low-dose aspirin can significantly affect the function of the intrinsic coagulation system, prevent the aggregation of platelets, but no effect on the function of the extrinsic coagulation system. On the other hand, it can also increase the deposition of platelet on the anastomotic sites after end-to-end anastomosis, especially in the early stage when it is intravenously injected, but it is strong enough to cause thrombosis at the anastomotic sites. The effects of low dose aspirin on the coagulation system are inconsistent with its local effects on anastomotic sites.

Animals↗
PubMed2000

[Effect of electroacupuncture on mRNA expression of NGF and IGF-1 in injured nerve].

OBJECTIVE: To investigate the effect of electroacupuncture on mRNA expression of NGF and IGF-1 in injured nerve. METHODS: Sciatic nerve injury model was established by transection of right side sciatic nerve in 90 male SD rats, which were randomly divided into two groups. The experimental group was treated with electroacupuncture, no treatment in the control group. The distal part of the injured nerve was harvested after 1, 2, 4, 6 and 10 weeks of operation and stored in the liquid nitrogen. The total RNA was extracted by the TRIzol reagent. Reverse transcriptase-polymerase chain reaction(RT-PCR) was used to detected the mRNA expression of NGF and IGF-1. RESULTS: The mRNA expression of NGF in the experimental group was increased quickly from the second week, and reached to highest level in the fourth week. It was much higher than that of the control group (P < 0.05). Then it began to decline in following time and approximately reached to the level of the first week after 10 weeks of operation. The mRNA expression of IGF-1 in the experimental group was remarkably increased in the second and fourth week, and which was much higher than that of the control group respectively(P < 0.05). Although the mRNA expression of IGF-1 after 10 weeks of operation in the experimental group was higher than that of the control group, but there was no significant difference between the two groups(P > 0.05). There was linear correlation in the fourth week between mRNA expression of NGF and IGF-1 in the experimental group. CONCLUSION: The mRNA expression of NGF and IGF-1 can be elevated in injured nerve at early stage interfered with electroacupuncture.

Animals↗
PubMed2000

[Application of silks as scaffolds for three-dimensional culture of chondrocytes].

OBJECTIVE: To observe the effects of silks on attachment, shape and function of chondrocytes cultured in vitro. METHODS: The silks from silk worm cocoons were digested by trypsin and coated with polylactic acid to from three dimensional scaffolds for rabbit rib chondrocyte culture. The growth and shape of chondrocytes were observed with phase contrast microscopy, scanning electron microscopy. RESULTS: The chondrocytes were adhered to silks slowly after chondrocytes were seeded into silk scaffolds and cells fixed on silks well 1 or 2 days later. Cells began to proliferate after 3 days and multiplicative growth was observed on the 6th day. Microholes of silk scaffolds were filled with chondrocytes 2 weeks later. Scanning electron microscopy showed that there was a lot of extracellular matrix surrounding cells. CONCLUSION: Silks are ideal for attachment, growth and function maintenance of chondrocytes, and silks can be used as scaffolds for chondrocytes in three dimensional culture.

Animals↗
PubMed1999

[Experimental study of morphology and electrophysiology on denervated skeletal muscle].

OBJECTIVE: In order to provide the scientific basis to find out a practical and effective method to evaluate the degree of muscle atrophy and a better method of prevention and treatment of skeletal muscle atrophy. METHODS: Forty-two adult Spray-Dawley rats were used and the model of denervated gastrocnemius muscle was established by cutting off the tibial nerve. The muscle wet weight, diameter and cross section area of myocyte were measured. The motor end-plate, fibrillation potential amplitude and frequency of denervated skeletal muscle were observed. RESULTS: The muscle wet weight rapidly reduced within 4 weeks. Afterwards, it maintained about 30 per cent of normal value, and the diameter and cross section area of myocyte progressively reduced. The motor end-plate slightly changed within 4 weeks, but its degeneration accelerated in 6 weeks and disappeared after 16 weeks. The fibrillation potential amplitude was maximum at 2 weeks and it progressively reduced after 12 weeks of muscle denervation. The changes of amplitude and frequency were consistent with the degeneration of end-plate. CONCLUSION: The muscle wet weight, diameter and cross section area of myocyte, fibrillation potential amplitude and frequency could be considered as the morphological and electrophysiological indexes of muscle atrophy degree. It's suggested that the repairing operation of peripheral nerve should be performed before the disappearance of motor end-plate.

Animals↗
PubMed1999

[Immunohistochemical study of S-100 protein in degenerative nerve after different pathological brachial plexus injuries].

OBJECTIVE: To explore the regularity of the change of S-100 protein in degenerative nerve after different pathological brachial plexus injuries. METHODS: Eighty SD rats were randomly divided into two groups, right C5, C6 preganglionic injury, and postganglionic injury. The distribution and content of S-100 protein in distal degenerative nerve were detected after 1, 2, 3 and 6 months of injury by immunohistochemical methods. RESULTS: The S-100 protein was mainly distributed along the axons. The S-100 protein positive axons of each time interval decreased after operation, with significant difference from normal nerves (P < 0.01). There was no statistically significant difference among 1, 2, 3 and 6 months group (P > 0.05). The S-100 protein stain of postganglionic group was negative. CONCLUSION: In preganglionic injury, the functional expression of Schwann's cells in the distal stump keeps at a certain level and for a certain period. Since Schwann's cell has inductive effect on nerve regeneration, it suggests that the distal nerve stump in preganglionic injury can be used as nerve grafts.

Animals↗
PubMed1998

Long-term functional results of contralateral C7 transfer.

From 1986 to 1994, 82 patients with brachial plexus root avulsion were operated on using a contralateral C7 nerve-root transfer. Forty-four patients underwent a one-stage procedure in which the distal end of the ulnar nerve was anastomosed to the contralateral C7 root, and the other 38 underwent a two-stage procedure (first phase: C7 root --> ulnar nerve; second phase: ulnar nerve --> recipient nerve). Twenty postoperative cases were followed-up for 2 years. Of them, the ulnar nerve was transferred to the musculocutaneous nerve in six cases, with recovery of the biceps up to M3 in four and S3 in five cases; the ulnar nerve was transferred to the median nerve in eight cases, with recovery of the wrist and finger flexors up to M3 in five and S3 in six cases; the ulnar nerve was transferred to the radial nerve in four cases, with recovery of the triceps up to M4 in two and S3 in three cases; and the ulnar nerve was transferred to the thoracodorsal nerve in two cases, with recovery of the latissimus dorsi to M4 in one case. The total muscle recovery rate (up to M3) of the series was 60 percent, and the sensory recovery rate (S3) was 78 percent. Outcomes were related to patient age, operative delay, and whether or not the ulnar nerve was used as a bridge for transfer.

Adolescent↗
PubMed1998

Femoral nerve transfer for treatment of brachial plexus root avulsion.

Femoral nerve transfer to the muscular branches of the thenar and hypothenar muscles was performed to determine its protective effect on the hand intrinsic muscles. Seven cases of brachial plexus root avulsion treated from May of 1989 to October of 1991 were involved. The femoral nerve transfer to the muscular branches of the thenar and hypothenar muscles was done at the same stage of multiple neurotization. The muscular branches derived from the femoral nerve were isolated and coapted with the thenar muscle branch of the median nerve and the deep branch of the ulnar nerve. A groin flap was harvested simultaneously to form a skin-tube pedicle that covered the nerve bridge. At the second stage, when regeneration of the median and ulnar nerves was found to reach as far as the level of the wrist, the femoral nerve was divided and the muscular branches of the thenar and hypothenar muscles were anastomosed with the regenerated median and ulnar nerves. All the cases were followed up for more than 6 years. Six months after femoral nerve transfer, muscle power of the interosseous muscles and adductor pollicis recovered to MRC3, whereas that of the abductor pollicis brevis recovered to MRC1 to 2. Five cases underwent second-stage transfer. Four to five years of follow-up revealed that the muscle power of the interosseous muscles and adductor pollicis was MRC2 in one case, MRC1 in three cases, and MRC0 in one case. As for the donor area, muscle power of the quadriceps femoris reduced to M3 to 4 within 1 month after femoral nerve transfer and recovered to normal at 3 months. In conclusion, femoral nerve transfer to the muscular branches of the thenar and hypothenar muscles has some protective effect on the hand intrinsic muscles. The outcome of the second stage, however, is not satisfactory.

Adolescent↗
PubMed1997

Functional motor innervation of brachial plexus roots. An intraoperative electrophysiological study.

The electrophysiological properties of the normal brachial plexus and functional motor innervation were examined during the operation of transfer of contralateral C7 transfer from the healthy side. Different roots of the brachial plexus were stimulated and maximum amplitudes were recorded. The results showed that functional motor innervation of brachial plexus roots were: C5 mainly forms the axillary nerve to innervate the deltoid muscle; C6 mainly forms the musculocutaneous nerve to innervate biceps; C7 mainly forms the radial nerve to innervate triceps; C8 mainly forms the median nerve to innervate flexor digitorum superficialis and profundus; and T1 mainly forms the ulnar nerve to innervate the intrinsic muscles of the hand.

Adult↗
PubMed1997

Long-term results of toe transfer: retrospective analysis.

Between February 1966 and February 1994, 400 cases of toe transplantation were analyzed, to evaluate toe-transfer procedures in thumb and finger reconstruction. Techniques utilized included single second-toe transfer, with and without the metatarsophalangeal joint (299): second- and third-toe transfer (28); second-toe and third proximal phalanx transfer (1); second-toe with flap transfers (66); and hallux nail flap with second toe or second and third toe transfer (6). There was a survival rate of 96.5 percent, with 386 cases surviving and 14 failing. A more than 2-year follow-up was possible in 240 cases. Excellent motor and sensory function (more than 90 percent of normal) was achieved in the reconstructed fingers and thumbs, as well as satisfactory function (between 86 and 91 percent of normal) in the donor foot.

Adolescent↗