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Biomedical subjects

J Wong

Publications and source records attributed to J Wong.

At least 559 records · Page 31Linked to original sources
PubMed1988

Influence of age on the mortality from acute pancreatitis.

The influence of age on the mortality rate of 268 patients with acute pancreatitis was studied. The hospital mortality rate for patients aged below 50 years was 5.9 per cent. The figure increased to 21.3 per cent in patients aged over 75; the high mortality was accounted for by a higher incidence of deaths related to concomitant medical or surgical diseases in the same hospital admission rather than to complications resulting directly from the pathological process of acute pancreatitis. When only deaths due to complications of acute pancreatitis were analysed, the mortality rate was not significantly different between the young and elderly groups. Moreover, the complication rate and the proportion of patients having severe disease (judged by the number of prognostic signs) were not higher in the elderly. Thus acute pancreatitis was intrinsically not more serious were it not for the presence of concomitant diseases with advanced age.

Acute Disease↗
PubMed1988

Teratological assessment of exposure to time-varying magnetic field.

A teratological assessment was performed using rats that were exposed to an alternating magnetic field. The magnetic field had a sawtooth waveform similar to that produced by video display terminals (VDTs). Female rats were exposed 2 weeks prior to and throughout pregnancy at a rate of 7 h/day. Three intensities of magnetic field (5.7, 23 or 66 microT) were used. All of these field intensities were much greater than those to which VDT users are exposed. A slight but statistically significant decrease in maternal lymphocyte count for the highest intensity field was found as compared with the control group. However, the lymphocyte count was within the normal range, and the observed changes in hematological parameters were considered mild. No other maternal or fetal parameters that were examined showed a significant difference for any of the three field intensities. Where minor variations in skeleton development were observed they were known to be the common "noise" that appears in every teratological evaluation.

Animals↗
PubMed1988

The effect on airway function of inspired air conditions after isocapnic hyperventilation with dry air.

The magnitude of postexercise or posthyperventilation bronchoconstriction in patients with asthma is related to the temperature and the water content of the inspired air during the exercise or hyperventilation period. Recent studies have suggested that the inspired air conditions during recovery from exercise may also be important in determining the magnitude of postexercise airway narrowing. In the present study, normal subjects (n = 8) and patients with asthma (n = 12) were studied on separate days. On day 1 the subjects performed isocapnic hyperventilation with warm dry air and recovered breathing warm dry air. On the second day, an identical warm dry air challenge was administered, but recovery occurred while they were breathing warm humid air. There was no significant bronchoconstriction in the normal subjects, irrespective of the inspired air conditions during recovery. The patients with asthma showed greater bronchoconstriction during recovery in warm, humid air (maximal decrease in FEV1 31% +/- 17%) than in dry air (maximal decrease in FEV1 19% +/- 20%; p less than 0.05). These results suggest that the inspired air condition during recovery from isocapnic hyperventilation of dry air is also a determinant of the magnitude of the bronchoconstrictor response.

Adult↗
PubMed1988

High spatial resolution spectroscopy in the elemental microanalysis and imaging of biological systems.

The application of analytical electron microscopy to the high spatial resolution study of biological systems is reviewed. Specimen preparation, quantitative analysis, capabilities and limitations are all discussed, principally in the context of energy-dispersive X-ray analysis. Results are presented using both current techniques and the developing quantitative image analysis. Finally the role of new instrumental approaches, including electron energy loss spectrometry, is discussed.

Animals↗
PubMed1988

Synergistic interactions of ciprofloxacin and extended spectrum beta-lactams or aminoglycosides against Acinetobacter calcoaceticus ss. anitratus.

The susceptibility of 54 clinical isolates of Acinetobacter calcoaceticus ss. anitratus to 16 antimicrobial agents was determined in vitro with inoculum of 10(4) and 10(6) cfu by a standard agar dilution method. The most active agents were imipenem, SCH 34343, ciprofloxacin, difloxacin (A-56619), and A-56620. Only imipenem and Abbott quinolones (A-56619 and A-56620) remained active when tested with the heavier inoculum. Except for ticarcillin and ceftazidime, which showed only moderate activity, the extended-spectrum penicillins and cephalosporins, as well as aztreonam and aminoglycosides, were inactive against these highly resistant strains. Nine isolates were selected for combination studies of ciprofloxacin with seven beta-lactams and three aminoglycosides using a checkerboard agar dilution technique. Synergistic or additive interactions at clinically achievable concentrations were more common with amikacin (eight isolates), tobramycin (seven), ceftazidime (six), cefoperazone (six), and aztreonam (six), than with other agents, including mezlocillin (four), piperacillin (three), gentamicin (two), and cefsulodin (two). Antagonism was rare, only occurring with mezlocillin in a single strain. These data suggest that combinations of ciprofloxacin with these agents may be useful for some nosocomial multidrug resistant A. calcoaceticus ss. anitratus infections.

Acinetobacter↗
PubMed1988

Childhood recurrent pyogenic cholangitis.

Recurrent pyogenic cholangitis (RPC) is characterized by repeated attacks of bacterial infection of the biliary tract by enteric organisms resulting in formation of strictures and stones in the intrahepatic as well as the extrahepatic bile ducts. Between 1973 and 1984, we managed ten children with RPC. Presentation was acute, septicemia being invariably present. Four children responded to vigorous intravenous (IV) fluid and antibiotic therapy; of these, three subsequently required elective transduodenal sphincteroplasty. Six children required emergency biliary tract decompression surgically and three of them also had concomitant definitive drainage procedures (transduodenal sphincteroplasty, two; supraduodenal choledochoduodenostomy, one). The other three had T-tube drainage initially followed by elective drainage procedures (transduodenal sphincteroplasty, one; supraduodenal choledochoduodenostomy, two). At exploration, pigment stones and/or mud were invariably present in the bile ducts. One child required reexploration for hemostasis following sphincteroplasty, and one child died from septicemia and respiratory failure following operation. The rest are well, having been followed for 3 to 12 years. Major advances in recent years include (1) endoscopic retrograde cholangiopancreatography (ERCP) for accurate definition of the biliary tract and confirmation of the presence and location of stones during the quiescent phase, (2) the intraoperative choledochoscopic extraction of intrahepatic and extrahepatic stones, and (3) postoperative stone removal via the T-tube tract.

Bacterial Infections↗
PubMed1988

Proximal gastric vagotomy. The preferred operation for perforations in acute duodenal ulcer.

Simple closure, the conventional operation for perforated acute duodenal ulcers, is associated with symptomatic relapse in a large proportion of patients. In order to assess the role of immediate definitive surgery, 78 fit patients with perforated acute ulcers were prospectively randomized to undergo either closure alone or proximal gastric vagotomy with closure (PGV). Patients taking potentially ulcerogenic drugs or who had severe stress were excluded from the study. Both groups were comparable with respect to age, sex, general medical health, duration of perforation, length of ulcer history, and presence of duodenal scarring. There was no hospital mortality. Minor complications occurred in 7.3% after closure and 10.8% after PGV. At 3 years follow-up, the cumulative recurrence rates were 36.6% and 10.6% after closure and PGV, respectively (p = 0.001). Eighty-five per cent of recurrences after closure were symptomatic, and half of them required reoperation. Duodenal scarring itself did not appear to influence the outcome after closure. PGV was not associated with dumping, diarrhea or other unwanted side effects. Although less than that in chronic ulcers, there is a substantial risk of symptomatic relapse after closure of perforated acute duodenal ulcers. With judicious patient selection, PGV effectively reduces this risk without incurring disabling side effects associated with other ulcer operations.

Adult↗
PubMed1988

No decrease in duodenal ulcer surgery after cimetidine in Hong Kong.

We undertook a 12-year review of the elective and emergency surgery for duodenal ulcer in Queen Mary Hospital, Hong Kong, to ascertain whether the introduction of cimetidine as treatment for duodenal ulcer had led to a reduction in the number of elective and emergency operations being performed for duodenal ulcer. There was no decrease in the number of elective operations performed for duodenal ulcer. Indeed, in the same period, emergency operations for bleeding and perforated ulcers had increased.

Cimetidine↗
PubMed1988

Therapeutic functional bracing in upper limb fracture-dislocations.

The authors utilized the principle of functional bracing in the management of 307 fractures and/or dislocations of the upper limb. There were 29 humeral fractures, 111 fracture-dislocations around the elbow, 32 fractures of the forearm, and 135 fractures of the distal radius. The average follow-up was 9 months. The results showed that more than 95% of the patients regained good range of motion and power. The details of the technique and the protocols are described. The conclusion drawn from an analysis of the results is that functional bracing is a safe and effective method in the management of upper limb fracture dislocations.

Adolescent↗
PubMed1988

Changes in accommodation with age: static and dynamic.

Accommodative amplitude decreases with age, not with aging. The decrease is largely completed by age 40 years; only minor residual accommodation is present in most subjects after the mid-40s. Dynamical measurements show the accommodative response of subjects over 30 years of age to be significantly slowed (time constants of accommodation increases). Accommodation amplitude is less than 3 D by 30 years of age. Thus prepresbyopia is a sign of continual development, not of deterioration of the accommodative mechanism. Accommodation, or the change of clear vision with change in lens power, has been studied by many distinguished scientists including Descartes and Thomas Young. Helmholtz's "Theory of Accommodation" is a dual, indirect, active theory. There are both lenticular, including lens and capsule, and also extralenticular mechanisms, comprised of the zonule of Zinn or suspensory ciliary ligament and the ciliary muscle itself. The ciliary muscle does not act directly on the lens but indirectly through its action on the zonule of Zinn. Active contraction of the ciliary muscle, a unified muscle, produces accommodation; relaxation of the ciliary muscle permits relaxation of accommodation.

Accommodation, Ocular↗
PubMed1988

Acute pancreatitis in the aged.

Forty-seven patients aged more than 75 years with acute pancreatitis were studied. The most common cause of acute pancreatitis was biliary tract stones. The clinical presentation and severity of the disease as judged by the number of poor prognostic factors were not different from the group of patients aged less than 75 years. The mortality rate in the older group was thrice that of the younger group (21.3% versus 7.24%). The higher mortality rate was explained by a higher incidence of deaths related to complications of biliary stones and coincidental diseases. Significantly more aged patients with mild disease died, indicating the limitation of predictive ability of the scoring system in acute pancreatitis of the aged.

Acute Disease↗
PubMed1988

Synergistic interactions of ciprofloxacin and extended-spectrum beta-lactams or aminoglycosides against multiply drug-resistant Pseudomonas maltophilia.

The susceptibility of 28 clinical isolates of Pseudomonas maltophilia to 16 antimicrobial agents was determined in vitro by a standard agar dilution method with inoculum sizes of 10(4) and 10(6) CFU. All isolates exhibited multiple drug resistance. Nine isolates were selected for studies of combinations of ciprofloxacin with seven antipseudomonal beta-lactams and three aminoglycosides by a checkerboard agar dilution technique. Synergistic or additive combinations of ciprofloxacin in clinically achievable concentrations were most frequent with mezlocillin (89%), followed by cefoperazone (67%), piperacillin (56%), cefsulodin (56%), and ceftazidime (33%), and were infrequent with aztreonam (11%), the aminoglycosides (0 to 14%), or imipenem (0%). Antagonism was not observed in any combination. These data suggest that combinations of ciprofloxacin with these agents may be useful for some nosocomial multiply drug-resistant P. maltophilia infections.

Aminoglycosides↗
PubMed1988

Long ischaemic stricture of the interposed colon.

A case is reported of a long segment stricture in a colonic oesophageal replacement with radiographic evidence to support the diagnosis of ischaemia. Ischaemia of the substitute organ following oesophageal resection is a well recognised, serious complication that usually results in anastomotic leakage. If the anastomosis heals primarily, late manifestations of ischaemia are rare.

Aged↗
PubMed1988

The role of lymphography in chylothorax following thoracic surgery.

Lymphography was used to investigate nine patients who presented with chylothorax after surgery of the thorax. Leakage of the lipiodol was identified from the thoracic duct in six patients and from tributaries of the thoracic duct in two patients. There was complete occlusion of the thoracic duct at the site of injury in two patients but leakage could not be visualized at the time of the procedure. The different methods of treatment of chylothorax and the influence of the lymphographic findings on management are discussed.

Chylothorax↗
PubMed1988

Compatibility of esmolol hydrochloride with morphine sulfate and fentanyl citrate during simulated Y-site administration.

The compatibility and stability of esmolol hydrochloride in admixtures during simulated Y-site injection of morphine sulfate or fentanyl citrate was studied. One milliliter of either morphine sulfate (15 mg/mL) or fentanyl citrate (0.05 mg/mL) was injected into a running infusion of esmolol hydrochloride (10 mg/mL) in 5% dextrose and 0.9% sodium chloride injection, and the solution was visually observed for changes. To determine the stability of the drugs during Y-site injection, esmolol hydrochloride 4 mL (1000 mg) in 5% dextrose and 0.9% sodium chloride injection was combined with 100 mL of either morphine sulfate 15 mg/mL or fentanyl citrate 0.05 mg/mL to simulate concentrations of the drugs that might be expected during Y-site injection. The admixtures were stored at ambient room temperature under normal light, and drug concentrations were determined using high-performance liquid chromatography at time zero and at two, four, and eight hours. Admixtures were also tested for pH and observed for visual changes. No immediate changes were observed in any of the admixtures, and the concentrations of the drugs varied by less than 4% throughout the study period. No precipitate or color changes were noted during Y-site injection of either drug into the running esmolol infusion. Under all of the conditions studied, esmolol hydrochloride in 5% dextrose and 0.9% sodium chloride injection is compatible with morphine sulfate or fentanyl citrate.

Adrenergic beta-Antagonists↗
PubMed1988

Malignant hilar biliary obstruction treated by segmental bilioenteric anastomosis.

Segmental bilioenteric anastomosis procedures were performed on 22 patients with malignant hilar biliary obstructions. The majority of the bypasses were done to the segment 3 duct and a single anastomosis was performed in each patient. The operative mortality rate was 13.6% and morbidity, 27.3%. The biliary obstruction was completely relieved in 5 patients, partially but satisfactorily relieved in 11 patients, and not relieved in 3 patients. The mean survival was 8 months, and the median survival was 6 months. Late complications were seen in 42% of the patients, and these complications included cholangitis, liver failure, and duodenal obstruction. An analysis of the operative results with respect to the presence of right and left ductal system communication showed that when communication was absent, there was a greater incidence of unsuccessful relief of the biliary obstruction. When communication was present, the incidence of late cholangitis that involved the undrained side was greater.

Aged↗