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Biomedical subjects

R Wong

Publications and source records attributed to R Wong.

At least 127 records · Page 7Linked to original sources
PubMed1994

Use of the Hickman-Crawford critical care catheter in marrow transplant recipients: a pulmonary artery catheter-adaptable central venous access.

OBJECTIVE: To describe the use of a modified 15.5-Fr double-lumen, tunneled right atrial catheter (Hickman-Crawford catheter) in adult bone marrow transplant recipients, that permits passage of a 5-Fr pulmonary artery catheter through the larger of the catheter's lumens. DESIGN: A case series review of the clinical experience with a modification of the existing central venous catheter design. SETTING: A bone marrow transplantation center. PATIENTS: Fourteen patients (weighing at least 50 kg body weight) undergoing bone marrow transplantation. Ages ranged from 18 to 64 yrs (median 40). There were nine male and five female patients. All patients, except for three who were receiving autologous marrow transplants, underwent allogeneic transplants. MEASUREMENTS AND MAIN RESULTS: Sixteen catheters were inserted into the subclavian vein in 14 patients. The catheters remained in place for a mean of 44 days (median 30; range 6 to 107) and 56% remained functional until removed an average of 60 days later at the time of death (n = 5) or discharge to home (n = 4). One catheter was accidentally dislodged by the patient and six catheters (38%) were electively removed, two because of infection and four because of mechanical occlusion or damage. The Hickman-Crawford catheter was used as venous access for insertion of 21 pulmonary artery catheters in 12 patients (twice in seven patients). Ninety percent of these insertions (19 of 21) were done without difficulty; use of a guidewire was required in the remaining two cases. No complications of pulmonary artery catheterization were seen. CONCLUSIONS: This experience illustrates that a tunneled right atrial catheter for long-term use can be employed safely and repeatedly for insertion of pulmonary artery catheters for central hemodynamic monitoring.

Adolescent↗
PubMed1994

Risk of nonshunt abdominal operation in the patient with cirrhosis.

BACKGROUND: The hazards of operative treatment for variceal hemorrhage and intractable ascites in patients with cirrhosis are well known. Much less information is available on the morbidity and mortality in these patients after abdominal operations not directly related to the sequelae of portal hypertension. STUDY DESIGN: We reviewed the records of 77 consecutive histologically proved cases of cirrhosis in patients undergoing 85 general surgical, abdominal procedures during a ten year period. Logistic regression analysis was done on 32 preoperative and intraoperative variables with relation to postoperative outcome. RESULTS: There were 47 men and 30 women, with a mean age of 61 years (range of 28 to 86 years). The 30-day mortality rate was 18 percent (15 of 77 patients). Emergent operation was associated with a mortality rate of 32 percent (11 of 35 patients) compared with 8 percent (four of 50 patients) after elective procedures (p < 0.05). Extensive complications occurred in 28 percent of patients (24 patients; 14 percent after elective operative treatment and 49 percent after emergent procedures). The mortality rate was greatest after gastric procedures (38 percent). Other factors of statistical significance (p < 0.05) associated with poor postoperative outcome included cachexia, preoperative transfusion of fresh frozen plasma, and intraoperative platelet transfusion. Surprisingly, operative blood loss, presence of ascites, and operative time were not associated with increased complications or death. CONCLUSIONS: We conclude that elective, nonshunt abdominal operations can be performed with acceptable morbidity and mortality rates in selected patients with cirrhosis.

Abdomen↗
PubMed1994

The impact of unit-based self-management by nurses on patient outcomes.

OBJECTIVE: Patients discharged from a self-managed nursing unit are compared with patients from traditionally managed units on postdischarge outcomes. DATA SOURCES AND STUDY SETTING: Primary data were collected on patients discharged from eight nursing units in three clinical areas in one hospital from August through November 1990. STUDY DESIGN: A case series of eligible patients discharged from four self-managed nursing units (n = 140) are compared with patients from four matched traditionally managed units (n = 138) on postdischarge outcomes: perceived health status, perceived functional status, needs for care, unmet needs for care, unplanned health care visits, and readmissions to the hospital within 31 days of discharge. DATA COLLECTION METHODS: Patients were interviewed by telephone at approximately two weeks postdischarge, and data from hospital records were merged with interview data. PRINCIPAL FINDINGS: Bivariate and multiple logistic regression analyses showed no significant effects (either positive or negative) of self-managed units on the postdischarge outcomes studied. CONCLUSIONS: Self-managed nursing units, previously shown to improve nurses' work satisfaction and retention, have no impact on patient postdischarge outcomes.

Adolescent↗
PubMed1994

Response latency of gerbils and hamsters to nuts flavoured with bitter-tasting substances.

The unconditioned reactions of Mongolian gerbils to peanuts rolled in sucrose octa-acetate (SOA) or denatomium benzoate (Bitrex) were studied in Experiment 1. Although SOA evokes as high a bitterness rating among humans as quinine salts, the gerbils' latency to ingest a nut flavoured with the former was similar to that to an unflavoured nut. Their oral latency to a nut that was flavoured with Bitrex was longer than to either an unflavoured one or one flavoured with SOA. However, the fact that they ingested a nut flavoured with the "most bitter substance known to man" within 70 sec after contact is surprising. Experiment 2 dealt with the effects of a peanut that was either unflavoured or flavoured with SOA or quinine and then paired with a LiCl injection. The oral latency of these gerbils to a nut conveying such flavours was assessed for six days after this conditioning. A nut flavoured with quinine acquired aversive properties but not ones that were flavoured with SOA or were unflavoured. Similar results were observed in Experiment 3, when hamsters were tested under comparable conditions. The theoretical implications of these results are discussed.

Acetates↗
PubMed1994

Comparative clinical evaluation of two professional tooth-whitening products.

A 2-week study was conducted to compare the tooth-whitening efficacy of two 10% carbamide peroxide products: Colgate Platinum Professional Toothwhitening System and Rembrandt Lighten Bleaching Gel. Fifty subjects were divided into two groups and assigned a product to use for 2 weeks. Change in tooth color was measured by reflectance spectroscopy at the initiation of study, at 1 week, and at 2 weeks into the study. Color change was calculated using the color-difference equation established by the Commission International de L'Eclairage. Results showed that Colgate Platinum was 62% more effective at tooth whitening after 1 week and 83% more effective after 2 weeks of treatment vs Rembrandt. At the termination of the study, the mean color difference (deltaE) for Colgate Platinum was 4.29 and 2.34 for Rembrandt. Statistical analysis demonstrated that the Colgate product is significantly superior at increasing tooth whiteness, increasing tooth lightness, reducing redness, and reducing yellowness. In this study, no adverse reactions were noted on clinical examination and none were reported by panelists with normal healthy dentition.

Analysis of Variance↗
PubMed1994

Clinical comparison of Colgate Platinum Toothwhitening System and Rembrandt Gel Plus.

A 2-week, three-cell study was conducted to evaluate the tooth-whitening efficacy of the Colgate Platinum Professional Toothwhitening System vs Rembrandt Gel Plus (a regimen of products consisting of a 10% carbamide peroxide gel, a whitening toothpaste, and a mouthrinse), and a placebo paste. Seventy subjects completed this parallel, single-blind, three-compartment, randomized clinical study. The subjects were balanced into two groups based on a minimal shade of A3 on the Vita shade guide and assigned a product. The duration of product usage was 1 hour twice daily for 2 weeks. Change in tooth color was measured by reflectance spectroscopy using a colorimeter. The readings were taken in the L*, a*, b* color space at the initiation, at 1 week, and at 2 weeks of the study. Calculation of color change (delta E) was performed using the color difference equation established by the Commission Internationale de L'Eclairage. Visual evaluation of shade changes was performed using the Vita shade guide. Results from this clinical study showed that Colgate Platinum was 77.7% more effective at tooth whitening after 1 week and 41.8% more effective after 2 weeks of treatment vs the Rembrandt regimen. Results showed that the Colgate product is significantly superior vs Rembrandt at increasing tooth whiteness (increase in delta E). Shade guide changes showed an overall improvement of 7.08 Vita tabs for the Colgate product and 5.12 Vita tabs for the Rembrandt regimen.

Adult↗
PubMed1993

Compressed air diving and respiratory disease. A discussion document of the Thoracic Society of Australia and New Zealand.

OBJECTIVE: To review the pathophysiology and respiratory complications of compressed air diving, and to formulate guidelines for assessing respiratory fitness to dive so that diving candidates can be advised of the risks associated with respiratory disease, in particular asthma. DATA SOURCES: Specialist medical journals in the areas of respiratory medicine, physiology and diving medicine. Morbidity and mortality statistics were obtained from international diving bodies, diving medicine scientific meetings, and papers. SYNTHESIS: The major complications of underwater diving in subjects with compromised respiratory function are drowning, pulmonary barotrauma and arterial gas embolism. Diving candidates with a history of asthma, pneumothorax, obstructive or restrictive lung disease, lung cysts or thoracic trauma should be advised not to dive in view of these risk factors. CONCLUSIONS: Several respiratory diseases carry an increased risk of morbidity and mortality from compressed air diving. An accurate history and measurement of lung function are an essential part of assessing fitness to dive, both to advise potential divers appropriately and to reduce risks associated with this increasingly popular recreational activity.

Asthma↗
PubMed1993

A retrospective comparison of transanal surgery and endocavitary radiation for the treatment of 'early' rectal adenocarcinoma.

OBJECTIVE: To compare two techniques for the local treatment of "early" rectal adenocarcinoma. DESIGN AND STUDY PARTICIPANTS: A retrospective comparison of 27 patients who underwent transanal disk excision and fulguration (group A) and 38 patients who underwent transanal endocavitary radiation (group B). SETTING: Inpatient and outpatient. INTERVENTION: Group A patients had rectal adenocarcinoma treated with disk excision and fulguration. Group B patients received 100 to 125 Gy in four to five fractions using the Phillips RT-50 unit. MAIN OUTCOME MEASURES: Survival and local recurrence. RESULTS: The median follow-up for group A was 68 months; for group B, 38 months. The mean tumor diameter was 2.5 cm, all were grade 1 or 2. The local recurrence rate was 7.4% for group A and 21% for group B. Local recurrence was not correlated with tumor grade, location, or size but did correlate with tumor ulceration. CONCLUSION: For selected early rectal cancers, surgical excision and fulguration offers better local control than endocavitary radiation therapy, while survival was similar.

Adenocarcinoma↗
PubMed1993

Colonic mucosal pH in humans.

Mucosal pH was measured at specific anatomic segments within the colon using a flexible pH probe in patients prepared for colonoscopy. The data revealed similar pH measurements along the length of the colon, irrespective of the presence or absence of colorectal neoplasia. Patients exhibited a relatively acidic right colon; a more alkaline transverse, left, and sigmoid colon; and a relatively acidic rectum. There were no apparent gender- or age-related effects on colonic mucosal pH.

Colon↗
PubMed1993

Postoperative primary adrenal failure from bilateral hemorrhagic adrenal infarction associated with coagulation factor XI deficiency.

A 72-year-old man developed bilateral adrenal hemorrhage causing primary adrenal failure three days after total hip replacement, and was found to have coagulation factor XI deficiency. Factor XI deficiency usually causes mild bleeding which is not predictable on the basis of assayable factor XI levels. There have been no previous reports of bilateral adrenal hemorrhage in factor XI deficiency or other inherited coagulation factor deficiencies. We suggest that the risk of bilateral adrenal hemorrhage should be considered in any preoperative evaluation of patients with factor XI deficiency.

Adrenal Gland Diseases↗
PubMed1993

Characterization of two structurally novel HIV-1 protease inhibitors identified by rational selection.

The human immunodeficiency virus (HIV-1), associated with the AIDS (acquired immunodeficiency syndrome) epidemic, encodes an aspartyl protease that is essential for polyprotein processing in the virus (Navia et al., 1989). It has been demonstrated that inactivation of the protease either catalytically or by an inhibitor prevents infectious virion formation (Kohl et al., 1988; Darke et al., 1989). The acquired knowledge of key molecular interactions occurring between inhibitors and aspartyl proteases, as well as the structural similarities between HIV-1 protease and human renin was used to rationally select candidates for HIV-1 screening from the pool of analogs designed as renin inhibitors. A minimal number of chosen compounds were tested in an HIV-1 protease assay system. Two structurally novel peptides emerged as potent enzymatic protease inhibitors. This study highlights the selection process and characterizes the antiviral properties of the two novel analogs.

Acquired Immunodeficiency Syndrome↗
PubMed1993

The effects of unit self-management on hospital nurses' work process, work satisfaction, and retention.

A number of innovative practice models have been introduced in an effort to resolve the hospital nursing shortage and improve the working conditions and retention of registered nurses. This study examines the effects of a unit-level self-management model (including salaried compensation and gainsharing) in a number of clinical areas at The Johns Hopkins Hospital in Baltimore, Maryland. In comparisons of nurses on self-managed and traditional nursing units, outcomes examined were nurses' perceptions of their work process, nurses' work satisfaction levels, and nurses' retention. The self-management model is found to increase work satisfaction through effects on two work process variables: coordination of care and effective team performance. The model is also associated with higher retention. Nurses on self-managed units work longer hours but earn increased pay; the effects of hours and pay on work satisfaction and retention are discussed.

Baltimore↗
PubMed1993

Flavour neophobia in gerbils (Meriones unguiculatus) and hamsters (Mesocricetus auratus).

Flavour neophobia in gerbils and hamsters was studied by comparing the ingestive/pouching behaviour of these animals when presented with either a familiar unflavoured peanut or a novel one that imparted basic flavours such as sweet, salty, sour, or bitter. Neophobia was expressed by an aversion towards the novel nut manifested by greater latency either to ingest it (gerbils) or to deposit it in the cheek pouch (hamsters) relative to that of the unflavoured one. This method, involving reactions to the taste of novel solid food, provides a more sensitive measure than the traditional one measuring intake of a novel flavoured fluid. The results indicated that gerbils and hamsters encountering either a sweet, salty, or sour nut for the first time showed a neophobic reaction. However, there was no apparent sign of neophobia when the animals were tested with a nut flavoured with quinine. The theoretical implications of these findings are discussed.

Animals↗
PubMed1993

Bronchiolitis obliterans and rheumatoid arthritis. Report of a case in a Chinese patient on d-penicillamine and review of the literature.

Rheumatoid arthritis is the commonest connective tissue disease associated with bronchiolitis obliterans, a clinico-pathologic entity of bronchiolar inflammation and fibrosis reflecting injury to the small airways, and presenting with symptoms and signs of small airways obstruction. It may arise de novo or as a complication of therapy due to d-penicillamine, when a distinct histologic picture of bronchiolar constriction without intraluminal inflammatory polyps appeared to be predominant in most reported cases. This condition is associated with a high morbidity and mortality, and apart from cessation of d-penicillamine, there are no standard recommendations for treatment. Response to various immunosuppressive agents, including corticosteroid, azathioprine, and cyclophosphamide, had been variable and unsatisfactory. We report a case of bronchiolitis obliterans in a Chinese female treated with d-Penicillamine for rheumatoid arthritis with the first documented response to corticosteroid alone, and review the literature on this subject.

Adult↗
PubMed1992

Coat color genes and cage temperature effects on care of the body surface (COBS) behavior of Meriones unguiculatus.

Male and female Mongolian gerbils (Meriones unguiculatus) carrying three coat color alleles, agouti, sandy, and black, were tested for 15 min under three cage temperature conditions, warm (35-40 degrees C), neutral (20 degrees C), and cold (0-5 degrees C). A frequency count of scratching, face and body wash, belly/side rubs, and shaking was taken of these animals' activities during the test sessions. Sex differences were not evident but coat color and age temperature affected the belly/side rubs and shaking activities. There were also effects of cage temperature but not coat color on face/body wash and scratching. It appears that animals with these coat color variants manifest disparate patterns of COBS behavior when encountering different thermal environments.

Animals↗
PubMed1992

Staphylococcal septicaemia complicating intracavernosal autoinjection therapy for impotence in a man with diabetes.

Intracavernosal injection of vasoactive drugs is a safe, effective, and commonly used treatment for impotence in diabetic men. In prospective studies infection has rarely occurred. We report a case of life-threatening Staphylococcal septicaemia complicating this treatment in a 61-year-old man with Type 2 diabetes, probably due to a combination of an unsterile technique and drug-induced priapism. Infection is a potential risk in diabetic men using intracavernosal injection therapy and those offered it should be informed of the importance of a scrupulous sterile technique and the need to seek urgent medical help for decompression if an erection persists for more than 4-6 h.

Bacteremia↗
PubMed1992

Skeletal muscle metabolism in the chronic fatigue syndrome. In vivo assessment by 31P nuclear magnetic resonance spectroscopy.

BACKGROUND: Previous study of patients with chronic fatigue syndrome (CFS) has demonstrated a markedly reduced dynamic exercise capacity, not limited by cardiac performance and in the absence of clinical neuromuscular dysfunction, suggesting the possibility of a subclinical defect of skeletal muscle. METHODS: The in vivo metabolism of the gastrocnemius muscles of 22 CFS patients and 21 normal control subjects was compared during rest, graded dynamic exercise to exhaustion and recovery, using 31P nuclear magnetic resonance (NMR) spectroscopy to reflect minute-to-minute intracellular high-energy phosphate metabolism. RESULTS: Duration of exercise was markedly shorter in the CFS patients (8.1 +/- 2.8 min) compared with the normal subjects (11.3 +/- 4.3 min) (p = 0.005). There were large changes in phosphocreatine (PCr), inorganic phosphate (Pi), and pH from rest to clinical fatigue in all subjects, reflecting the high intensity of the exercise. The temporal metabolic patterns were qualitatively similar in the CFS patients and normal subjects. There were early and continuous changes in PCr and Pi that peaked at the point of fatigue and rapidly reversed after exercise. In contrast, pH was relatively static in early exercise, not declining noticeably until 50 percent of total exercise duration was achieved, and reaching a nadir at 2 min postexercise, before rapidly reversing. There were no differences in pH at rest (7.08 +/- 0.04 vs 7.10 +/- 0.04), exhaustion (6.85 +/- 0.17 vs 6.76 +/- 0.17) or early (6.64 +/- 0.25 vs 6.56 +/- 0.24) or late recovery (7.09 +/- 0.04 vs 7.10 +/- 0.05), CFS patients vs normal subjects, respectively (NS). Neither were there intergroup differences (NS) in PCr or Pi. Although, quantitatively, the changes in PCr, Pi, and pH were marked and similar in both groups from rest to exhaustion, the changes all occurred much more rapidly in the CFS patients. Moreover, adenosine triphosphate (ATP) was significantly (p = 0.007) less at exhaustion in the CFS group. CONCLUSIONS: Patients with CFS and normal control subjects have similar skeletal muscle metabolic patterns during dynamic exercise and reach similar clinical and metabolic end points. However, CFS patients reach exhaustion much more rapidly than normal subjects, at which point they also have relatively reduced intracellular concentrations of ATP. These data suggest a defect of oxidative metabolism with a resultant acceleration of glycolysis in the working skeletal muscles of CFS patients. This metabolic defect may contribute to the reduced physical endurance of CFS patients. Its etiology is unknown. Whether CFS patients' overwhelming tiredness at rest has a similar metabolic pathophysiology or etiology also remains unknown.

Adenosine Triphosphate↗