Biomedical subjects

S Y Hung

Publications and source records attributed to S Y Hung.

8 recordsLinked to original sources

PubMed1997

Efficacy of surgical treatment in traumatic central cord syndrome.

BACKGROUND: Controversy surrounds the treatment of traumatic central cord syndrome (TCCS), as there are strong advocates for nonsurgical treatment for most patients. However, conservative treatment has been shown to yield a longer period of discomfort from pain and weakness in certain cases. METHODS: In a retrospective review of 114 patients presenting with acute or chronic TCCS from 1988-94, four different age groups were separately observed under different treatments. Motor and sensory recovery were assessed. RESULTS: Better results were achieved in younger patients, with or without radiographic abnormalities, and in patients with clinically correlated encroaching cord lesions who received early surgical decompression. CONCLUSIONS: Surgical intervention for TCCS must be addressed with careful clinical and radiographic survey. Removal of offending lesions in the subacute period results in significant motor and sensory improvement in short-term and long-term follow-up.

Acute Disease↗

PubMed1997

Early seizures after severe closed head injury.

BACKGROUND: We studied the incidence and clinical significance of early post-traumatic seizures after severe closed head injury. METHODS: This prospective study is based on clinical observation of 3340 adult patients with severe closed head injuries, each of them having a Glasgow Coma Scale (GCS) 3 to 8 after trauma. Anticonvulsant agents were not given to these patients unless there was evidence of seizure. RESULTS: One hundred and twenty-one patients (3.6%) experienced seizures within 1 week after head injury; 42 of these (1.26% of the series) had seizures within 24 hours after trauma. The incidence of intracerebral parenchymal damage was found to be higher among those patients who developed seizures in the first week (66.1%) than in those who did not (62.7%). However this result did not reach statistical significance. The patients with early seizures had a lower mortality rate (p < 0.01). In patients who survived from the initial injury, the occurrence of early post-traumatic seizures did not appear to influence the neurological recovery at 6 months after injury. CONCLUSION: Presence of intracerebral parenchymal damage on CT scan after severe closed head injury does not increase the risk of early post-traumatic seizures. With proper treatment, patients presenting with early seizures may have a lower mortality rate. However, the occurrence of early seizures does not influence the neurological recovery in patients who survive the initial severe closed head injury.

Adolescent↗

PubMed1996

C1-C2 fracture-dislocations in children and adolescents.

OBJECTIVE: C1-C2 is the predominant level of cervical spine injuries in children and adolescents. Either a fracture of the dens or atlantoaxial dislocation (AAD) without fracture of the dens can occur. We present a number of cases to compare their clinical presentations and discuss the preferred method of treatment. MATERIAL AND METHODS: There were 12 cases of type II odontoid fracture and 10 cases of AAD without fracture over a 13-year period. There was a male predominance and traffic collisions were the major cause of injury. Two thirds of the dens fractures were in children over 13 years of age and seven out of ten dislocations without fracture were under 13 years of age. Eight patients with fractured dens suffered from spinal cord injuries but six of those with dislocations were neurologically intact. Two patients of fractured dens and one with AAD presented with chronic myelopathies because of undetected injuries. RESULTS: Three patients expired because of irreversible respiratory failure. Most of the fractured dens achieved bony union after 3 months of halo-vest immobilization but those patients with AAD without fracture usually needed a fusion procedure. Transoral decompression was performed in two cases of dens fracture malunion. All of the survivors of the dens fracture returned to normal or independent daily living. Six of the AAD patients returned to normal, one had a mild neural deficit, and one had persistent spastic quadriparesis. CONCLUSIONS: There is a higher incidence of atlantoaxial dislocation without fracture in children under 13 years of age and a higher incidence of dens fractures in those over 13 years of age. Those with fractures of the dens are more likely to present with evidence of neural injury while those with AAD are more likely to be neurologically intact; however, a correct diagnosis and proper management are mandatory to prevent chronic myelopathy. Halo-vest immobilization is sufficient for most fractures of the dens in children, with AAD usually requiring a fusion.

Adolescent↗

PubMed1994

Benign osteoblastoma of the spine--report of two cases.

Benign osteoblastoma is a rare spinal tumor, with the posterior element mainly involved. Symptoms do vary and there is a long diagnostic delay, especially in young people. We present two cases of benign osteoblastoma. One occurred in the atlas and presented with a painless neck mass. The other occurred in the lumbar spine with symptoms of long-term spinal pain and radicular pain. Preoperative Technetium bone scan and computed tomography (CT) resulted in exact localization and better operative planning. En bloc excision of tumor is indicated for complete pain relief and full return of spinal mobility.

Adult↗

PubMed1993

Effect of Beauveria bassiana and Candida albicans on the cellular defense response of Spodoptera exigua.

A marked difference in the cellular response of Spodoptera exigua was observed when larvae were challenged with the insect mycopathogen Beauveria bassiana versus the yeast Candida albicans. Both fungi were rapidly phagocytized by circulating hemocytes. The relative growth rate of C. albicans as measured by daughter cell formation was partially suppressed, whereas B. bassiana blastospores produced germ tubes at rates equivalent to those under in vitro conditions. Limited growth by C. albicans within the phagocytic cells stimulated nodulation by hemocytes resulting in the protection of challenged larvae to C. albicans. Alternatively, B. bassiana suppressed the spreading ability of S. exigua hemocytes. These suppressed larvae, while capable of phagocytizing C. albicans, were unable to produce multicellular nodules. Circulating vegetative cells of both C. albicans and B. bassiana were observed to proliferate within these immunosuppressed host larvae.

Animals↗

PubMed1993

Evasion of host defense by in vivo-produced protoplast-like cells of the insect mycopathogen Beauveria bassiana.

In vivo cells (hyphal bodies) of the hyphomycetous insect pathogen Beauveria bassiana collected from host Spodoptera exigua larval hemolymph were osmotically sensitive and lacked a well-defined cell wall. In light and electron microscope studies, a galactose-specific lectin purified from S. exigua hemolymph, concanavalin A (specific for alpha-mannose), and a polyclonal antibody to B. bassiana cell walls all bound to surfaces of in vitro-produced B. bassiana blastospores; however, none of these probes labelled the thin layer of extracellular material covering the plasma membranes of hyphal bodies. These cells were observed freely circulating in S. exigua hemolymph at 36 h postinfection, although immunocompetent hemocytes were known to be present. Additionally, association of hyphal bodies with hemocytes in monolayers was significantly less than for opsonized in vitro blastospores or submerged conidia. The absence of antigenically important galactomannan components on in vivo cells may therefore allow these cells to escape recognition and phagocytosis. Lack of structural components (e.g., chitin, as evidenced by the absence of binding of wheat germ agglutinin) may also be important with respect to evasion of host cellular defense mechanisms. Production of wall material resumed 48 to 60 h postinfection and therefore may coincide with loss of phagocytic capabilities of the hemocytes due to immunosuppressive effects of fungal metabolites. The protoplast-like cells may be formed by the action of hydrolytic enzymes in the hemocytes or by inhibition of fungal cell wall synthetases.

Animals↗

PubMed1990

Bilateral simultaneous transaxillary sympathectomy in treatment of palmar hyperhidrosis: report of 60 cases.

Bilateral simultaneous transaxillary sympathectomies (BSTS) were established in order to achieve a one-stage transaxillary sympathectomy in the treatment of palmar hyperhidrosis. The features of the BSTS were the patient's supine operative position, parapectoral incision, and bilateral simultaneous procedures. BSTS were safely performed on 60 patients during a 5-year period. No serious complications or recurrences were encountered. The clinical results suggest that BSTS is the technique of choice for one-stage transaxillary sympathectomy in the treatment of palmar hyperhidrosis.

Adolescent↗

PubMed1983

Bacteriological study in chronic maxillary sinusitis.

The bacterial findings of 73 maxillary sinuses in 48 patients with chronic maxillary sinusitis, together with 7 non-inflamed sinuses, are reported. Employing an intraoperative technique and simultaneous collection of 3 different types of specimens in the present investigation made possible comparison of their bacterial characteristics. The results indicated that intraoperative culture of antral mucosa seems to provide the most reliable finding of bacterial flora in chronic maxillary sinusitis. The anaerobic bacteria were never found in the mucosal culture of non-inflamed sinus. The anaerobes appeared to invade the sinus cavity following the sealing of the ostium through the lymphatic or venous system and maintain the inflammatory process. Microbiological analysis of the results between the infected and non-inflamed sinuses established anaerobic bacteria as the most important pathogen in chronic maxillary sinusitis. The predominant anaerobes recovered in descending order of frequency were Veillonella sp., Peptococcus sp., Propionibacterium acne and anaerobic nonspore-forming GPB. Statistical analysis of the results of mucosal culture of inflamed and control materials demonstrated that those aerobic and faculatative bacteria recovered in the inflamed sinus appeared to be the normal inhabitants of non-inflamed sinus mucosa. The presence of normal flora in the normal healthy sinus mucosa may explain the chain of events that follows the occlusion of the ostium. These aerobic bacteria may become pathogenic and play a role in the pathogenesis of sinusitis.

Adolescent↗