PubMed Health⌕ Search

Biomedical subjects

D S Cheung

Publications and source records attributed to D S Cheung.

9 recordsLinked to original sources
PubMed1999

Evaluation of the patient with closed head trauma: an evidence based approach.

This article approaches the subject of closed head trauma from the time-sensitive vantage point of the emergency physician. As the clinical scenario unfolds, he or she constantly evaluates the need for diagnostic tests as information is received from paramedics, nurses, and the history and physical examination. This article provides a synopsis and a critique of original clinical trials to aid the emergency physician in making an evidence based decision.

Adolescent↗
PubMed1997

Hemangioma in twins.

A cohort of 118 twin pairs with infantile hemangioma was reviewed to determine clinical characteristics and to estimate the relative contribution of hereditary and/or environmental factors to pathogenesis. Questionnaires were sent to parents of twins in Massachusetts and Australia. Zygosity was determined by clinical questions. Accuracy of ascertainment was based on clinical and anatomic criteria. Race, gender ratio, topographic distribution, number of lesions, age of onset, and complications were all consistent with demographic data from other studies of infantile hemangioma. Of the 118 pairs, 40 were monozygotic twins (32 like-sex females and 8 like-sex males, and 78 were dizygotic (30 like-sex females, 17 like-sex males) and 31 unlike sex). The concordances in monozygotic and dizygotic female twins were 32% and 20%, respectively (p = 0.5). In like-sex male monozygotic and dizygotic pairs, the concordances were 25% and 12%, respectively (p = 0.4). These differences were not statistically significant. This study suggests that hereditary factors are not paramount in causing hemangioma. However, being female, fair-skinned, Caucasian, and having a positive family history presumably lowers the threshold for hemangiogenesis wherein extragenetic factors can trigger the appearance of this most common tumor of infancy.

Child↗
PubMed1997

Timed appearance of lymphocytic choriomeningitis virus after gastric inoculation of mice.

Arenaviruses present an emerging health threat in agrarian areas of Africa and South America; however, the natural routes of arenaviral infections are not clearly understood. Our previous studies with lymphocytic choriomeningitis virus (LCMV), the prototype arenavirus, implicate oral and intragastric routes as natural routes of infection. Our studies raised many questions about the primary site of infection and the route of dissemination after gastric infection. In this report, we use in situ hybridization to detect LCMV in various organs at different time points (0 to 96 hours). After gastric inoculation, the gastric mucosa is the initial site of viral infection, followed by infection of the spleen and liver, then ileum and last, lung, kidney, brain, and esophagus. Furthermore, our observations suggest that virus is disseminated lymphatically rather than by a hematogenous route. Infectious center assays using mononuclear cells from stomach, blood, and spleen of mice infected by the gastric route confirmed active infection with LCMV and the presence of mononuclear cells producing infectious virus in these tissues. This is the first identification of gastric epithelia as a primary site of virus infection.

Animals↗
PubMed1996

Murine infection with lymphocytic choriomeningitis virus following gastric inoculation.

Laboratory studies of arenaviruses have been limited to parenteral routes of infection; however, recent epidemiological studies implicate virus ingestion as a natural route of infection. Accordingly, we developed a model for oral and gastric infection with lymphocytic choriomeningitis virus to enable studies of mucosal transmission and vaccination by this additional route.

Animals↗
PubMed1996

[Management of anterior vitreous by high gluey Healon].

PURPOSE: To investigate the technique of managing anterior vitreous by high gluey Healon. METHODS: In 15 eyes of 15 cases having undertaken in situ phacoemulsification vitreous loss, 12 eyes of 12 cases in ECCE, 3 eyes of 2 cases in Marfan Syndrome, 13 eyes of 13 cases in eye injury, tunnel incision was made and PC-IOL implantation was performed after high gluey Healon managing anterior vitreous on all the cases. RESULTS: High gluey Healon managing anterior vitreous in 43 eyes, post capsule injuries was not enlarge, and cortex or fragments of len nuclear not fall in vitreous cavity. Visual acuity of 0.5 or better at postoperative one week were 72.1% and 59.1% respectively. CONCLUSION: The technique of managing anterior vitreous by high gluey Healon was worthy to be spread due to minimum injury, vitreous loss, and fast restoration of visual acuity.

Adolescent↗
PubMed1994

The influence of graft type on patency of infrainguinal arterial bypass grafts.

Between 1985 and 1992, 328 patients underwent 392 infrainguinal reconstructions. Indications for operation were disabling claudication in 126 patients, critical limb ischemia in 246 and uncomplicated popliteal aneurysm in 20. Grafts were to the above knee popliteal artery in 134 patients, below knee popliteal artery in 176 and infrapopliteal ("distal") in 82 patients. Graft types included 160 reversed saphenous vein (RSV), 95 polytetrafluoroethylene (PTFE), 84 nonreversed saphenous vein (NRSV), 41 composite grafts (PTFE plus vein) and 12 others. Results show the five year patency rate for all grafts of 58 percent and limb salvage (for limb ischemia) of 74 percent. Above knee and below knee popliteal grafts (three year patency rates of 72 and 66 percent) performed significantly better than distal grafts (51 percent three year patency rate, p < 0.025). NRSV grafts comprised 63 ex situ ("translocated") and 21 in situ grafts. No significant difference was shown between these (two year patency rates of 62 and 65 percent). There was no significant difference between RSV and NRSV grafts in this series, although RSV tended to show higher patency rates. Composite grafts (below knee, three year patency rate of 45 percent) had significantly lower three year patency rates than below knee RSV (79 percent, p < 0.005). RSV remains the conduit of choice in this unit, with long term patency comparable with other published series. Use of NRSV (translocated and in situ) allows increased use of autogenous vein with the associated higher patency rates compared with prosthetic materials and is the graft of choice if the long saphenous vein is not suitable for use in the standard reversed method. The translocated technique allows more flexibility in the use of nonreversed vein with results comparable with the in situ technique. Composite grafts provide a useful alternative to PTFE alone for infrageniculate grafting when insufficient autogenenous vein is available.

Adult↗