Search PubMed⌕ Search

Biomedical subjects

C Ng

Publications and source records attributed to C Ng.

At least 73 records · Page 4Linked to original sources
PubMed1991

A prospective study of 245 open digital fractures of the hand.

We report a prospective study of 245 open digital fractures of the hand in 201 patients. Management followed clear guidelines set out in protocol. The incidence of infection (2.04%) and non-union (2.45%) was low. Proximal phalangeal fractures and comminuted fractures did worst and associated significant soft tissue injuries had a particularly deleterious effect on the outcome. A classification based on the different soft-tissue components involved is proposed. In fractures associated with simple lacerations or isolated digital nerve injury only, one can expect about 40% good results and about 25% poor results. Where extensor tendon injury or extensive skin loss are also present, there will be approximately 18% good results and 50% poor results. If there is also injury to the flexor tendon or more than one component of significant soft-tissue damage, about 80% will be poor and good results are rare.

Adolescent↗
PubMed1991

Unstable phalangeal fractures: treatment by A.O. screw and plate fixation.

A prospective study of fifty-two fresh traumatic unstable fractures of the proximal or middle phalanges of the hand in forty-seven patients was reviewed. All the fractures were fixed with A.O. miniature screws and plates. The overall results were not satisfactory and complications were frequent. Only 26.9% of the fractures had good results. Fractures associated with significant soft tissue injuries had very poor results. When the present series was compared with a comparable group of fractures fixed with Kirschner wires, there was no significant improvement in the results. The unsatisfactory outcome of this group of unstable fractures may be largely due to the frequent association with poor prognostic factors.

Adolescent↗
PubMed1991

Noncontiguous regions in the extracellular domain of EGF receptor define ligand-binding specificity.

Murine epidermal growth factor (EGF) binds with approximately 250-fold higher binding affinity to the human EGF receptor (EGFR) than to the chicken EGFR. This difference in binding affinity enabled the identification of a major ligand-binding domain for EGF by studying the binding properties of various chicken/human EGFR chimera expressed in transfected cells lacking endogenous EGFR. It was shown that domain III of EGFR is a major ligand-binding region. Here, we analyze the binding properties of novel chicken/human chimera to further delineate the contact sequences in domain III and to assess the role of other regions of EGFR for their contribution to the display of high-affinity EGF binding. The chimeric receptors include chicken EGFR containing domain I of the human EGFR, chicken receptor containing domain I and III of the human EGFR, and two chimeric chicken EGFR containing either the amino terminal or the carboxy terminal halves of domain III of human EGFR, respectively. In addition, the binding of various human-specific anti-EGFR monoclonal antibodies that interfere with EGF binding is also compared. It is concluded that noncontiguous regions of the EGFR contribute additively to the binding of EGF. Each of the two halves of domain III has a similar contribution to the binding energy, and the sum of both is close to that of the entire domain III. This suggests that the folding of domain III juxtaposes sequences that together constitute the ligand-binding site. Domain I also provides a contribution to the binding energy, and the added contributions of both domain I and III to the binding energy generate the high-affinity binding site typical of human EGFR.

Animals↗
PubMed1991

Resistance to malaria in ankyrin and spectrin deficient mice.

Inbred mice carrying mutations in ankyrin and/or spectrin synthesis and assembly were studied for their ability to support the growth of the rodent malarias, Plasmodium chabaudi adami and P. berghei, in vivo. Mice carrying the nb/nb (normoblastosis) mutation which do not synthesize ankyrin and therefore also have a deficiency in membrane-bound spectrin, were refractory to P. chabaudi adami, which invades mature erythrocytes and to P. berghei, which invades reticulocytes. Similarly, sph/sph mice which do not synthesize the alpha chain of spectrin but do synthesize ankyrin, were also resistant to both parasites. The heterozygote for the nb defect (nb/+) exhibited a diminution of parasitaemia. We conclude that the host cell spectrin may be necessary for the invasion and/or growth of rodent malarial parasites.

Anemia↗
PubMed1991

Radiology of continent urinary diversion.

The continent urinary diversions described in this article represent only a small number of the techniques that have been reported in the urologic literature. An attempt has been made to discuss diversions that are currently in common use or have been recently described and hold potential for becoming more widely accepted. The radiologist with a basic understanding of continent urinary diversions plays an important role in evaluating patients who have had these procedures. Complications can be detected and evaluated and occasionally treated with interventional techniques. As continent urinary diversions become more frequently performed, it is important that radiologists become aware of their construction techniques, radiographic appearance, function, and potential complications.

Cecum↗
PubMed1991

A study of function and residual joint stiffness after functional bracing of tibial shaft fractures.

Ninety-eight diaphyseal tibial fractures were treated with custom made functional braces in 97 patients older than 14 years of age. The average follow-up period was 1.86 years, and 53 patients had more than two years' evaluation (average, 2.83 years). The majority of the patients did not have full range of movement in the ankle and subtalar joints when the brace was removed after fracture healing. Although the stiffness decreased with time, a significant number of patients were left with residual joint stiffness. At an average follow-up period of 1.86 years, 68.4% of the patients had normal ankle motion and 60% had normal inversion and eversion of the hindfoot. In patients with more than two years' evaluation, 75.5% had normal ankle movement and 71.1% had normal inversion and eversion of the foot. In the knee joint, the incidence of residual joint stiffness was small and the amount of stiffness was clinically insignificant. Patients with an abnormal walking pattern after fracture healing had a high incidence of ankle and subtalar joint stiffness.

Adolescent↗
PubMed1990

Cytokine production in lethal and non-lethal murine malaria.

Levels of IFN-gamma, IL-2 and IL-4 were measured in vitro during the course of non-lethal Plasmodium chabaudi adami and lethal P. chabaudi strain 1309 infections in BALB/cByJ mice. Spleen cells from mice infected with the non-lethal Plasmodium had a higher initial response to P. chabaudi antigens than mice infected with P. chabaudi strain 1309, as determined by measuring all three lymphokines. We conclude that both Th1 and Th2 subsets of T helper lymphocytes are activated during P. chabaudi adami infection but that these responses are suppressed in mice infected with the more virulent P. chabaudi strain 1309.

Animals↗
PubMed1990

Evaluation of results in flexor tendon repair: a critical analysis of five methods in ninety-five digits.

The development of an internationally accepted system of assessment of results after flexor tendon repair is important. In a prospective study of ninety-five digits, gross discrepancies were demonstrated between five popular methods of assessment: Buck-Gramcko, linear measurement, Grossman, American Society for Surgery of the Hand, and Strickland. The relative merits of each systems were studied and modifications for the Buck-Gramcko system are suggested.

Evaluation Studies as Topic↗
PubMed1989

Role of IFN-gamma in lethal and nonlethal malaria in susceptible and resistant murine hosts.

IFN-gamma plays an important role in host defense against microbial disease. Here, we studied the role of IFN-gamma in lethal and nonlethal murine malaria. Administration of recombinant murine IFN-gamma resulted in a dose-dependent protection of SW, BALB/cByJ, and CBA/J mice from the lethal variant of Plasmodium yoelii 17x (PyL) but had little effect on the course of the nonlethal variant of this parasite (PyNL). Administration of recombinant IFN-gamma also resulted in the activation of peritoneal macrophages for increased phagocytosis of malaria-infected erythrocytes and release of H2O2, as measured in vitro. The ability of spleen cells from infected mice to produce endogenous IFN-gamma and release H2O2 during the course of malaria was also studied. In BALB/cByJ mice, which are relatively susceptible to PyL and PyNL, there was an initial burst of IFN-gamma only in response to PyNL whereas in CBA/J mice, which are relatively resistant to these parasites, there was an initial burst of IFN-gamma in response to both PyL and PyNL. The kinetics of H2O2 release corresponded to that of IFN-gamma. In all infections, levels of IFN-gamma declined as parasitemia increased; however, nonlethal infections were characterized by a recovery of both IFN-gamma activity and H2O2 release as parasitemia declined. These data suggest that IFN-gamma may play an important role in modulating the course of malaria infections by activating macrophages for both intracellular and extracellular parasite destruction.

Animals↗
PubMed1989

Post-traumatic oedema of the foot after tibial fracture.

A total of 97 patients with diaphyseal tibial fractures treated with functional bracing were studied prospectively. Persistent ipsilateral foot swelling was present in 84.5 per cent of the patients. Most of the swellings subsided with time, but a small percentage of them persisted for a duration of 2 years or more after injury. The time for disappearance of the swelling in 50 per cent of the patients was 18.6 weeks. The development of oedema is not related to the age and sex of the patients, the configuration, type and level of the fractures, or the association of a fibular fracture. The bone healed quicker in those who did not have swelling of the foot. Once the swelling has developed, it seems to run its own course and its disappearance is not related to the age and sex, the configuration, type and level of fractures, the association of a fibular fracture, or the time for fracture healing. This complication does not have any adverse effect on the functional recovery of the patients.

Adolescent↗
PubMed1989

A prospective study on 284 digital fractures of the hand.

We report a prospective study on 284 digital fractures of the hand in 235 patients. Management followed clear guidelines set out in a protocol. Important factors in the selection of the treatment method were, acceptable alignment, functional stability, and associated "significant" soft tissue injuries. "Functionally" stable fractures treated by free mobilization had satisfactory results. Unstable fractures treated by splints or Kirschner wire fixation produced unsatisfactory results. "Open fracture," "comminuted fracture," and "associated significant soft tissue injuries" were identified as unfavorable prognostic factors. The anatomic site of the fractures was not important in determining the final outcome. About 15% of the displaced fractures became functionally stable after closed reduction and their results were comparable with the undisplaced fractures. About 30% of the patients had various degrees of difficulty after they returned to work. About 14% of the patients eventually changed their jobs because of their residual disability.

Adolescent↗