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Biomedical subjects

J W Jones

Publications and source records attributed to J W Jones.

At least 163 records · Page 9Linked to original sources
PubMed1992

A study of coagulase-negative staphylococci with reference to slime production, adherence, antibiotic resistance patterns and clinical significance.

Two hundred and fifty-one strains of coagulase-negative staphylococci (CNS) isolated from patients in hospital and the community were investigated for slime production and adherence as indicators of pathogenicity. Staphylococcus epidermidis formed 68.5% (126) of the isolates of CNS from blood and central venous catheter (CVC) tips, of which 46.0% (58) were slime-positive and adherent. Clinically significant infections were associated with 55.2% (32) of the slime-positive adherent strains isolated and 11.1% (four) of slime-negative non-adherent strains of S. epidermidis. For other species of CNS isolated from blood and CVC tips 74.1% (43) were slime negative non-adherent and 18.6% (eight) of these were considered clinically significant isolates while none of the slime positive adherent strains were associated with a clinically significant infection. Slime production and adherence were not characteristic properties of CNS causing community-acquired urinary tract infection or colonizing the nasal mucosa. It is concluded that slime production and adherence had a limited role in the differentiation between clinically significant and contaminant strains isolated from blood cultures; however, the absence of slime and adherence in isolates of S. epidermidis suggested a lack of pathogenicity.

Bacterial Adhesion↗
PubMed1992

Lethal effects of ivermectin on Anopheles quadrimaculatus.

Female Anopheles quadrimaculatus adults were blood fed on 15 mixed breed dogs 4 h after the dogs were given oral dosages of ivermectin. Dogs were divided into 5 treatment groups of 3 dogs each, at 10, 500, 1,000, 2,500 micrograms/kg, and untreated. Additionally, An. quadrimaculatus were fed on lambskin-membranes containing blood drawn from one dog in each treatment group. Mosquitoes were allowed to feed on the dogs or the lambskin-membranes and were observed for death at 24 and 48 h post-feeding. Greater than 90% mortality was recorded in all ivermectin treatment groups except at the 24 h post-feeding period with the 10 micrograms/kg dog dose blood fed through the lambskin-membrane (65.4% mortality). The highest 2 dosages produced 100% mosquito mortality at 48 h post-feeding from either a dog or the in vitro system using a lambskin-membrane.

Animals↗
PubMed1992

Artificial blood substitutes.

Investigations directed toward the development of an effective artificial blood substitute are continuing as concerns remain regarding the safety and adequacy of the nation's blood supply. Perfluorochemical compounds, modified hemoglobin solutions, and microencapsulated hemoglobin represent the major areas of research. If a successful red cell substitute can be developed, many problems inherent in current blood transfusion practices could be alleviated, particularly in emergency situations.

Blood Substitutes↗
PubMed1991

Immunological assay of erythrocyte acetylcholinesterase.

An immunoassay for the quantitation of erythrocyte surface acetylcholinesterase is described; using a red cell suspension, bound mouse monoclonal acetylcholinesterase antibody is detected by an alkaline phosphatase conjugated rabbit anti mouse IgG. Extraction is not required. In addition, the activity of erythrocyte surface acetylcholinesterase using dithiobisnitrobenzoate to detect released thiocholine has been measured. The coefficient of variation for each method is 7%. Reference ranges have been established for healthy adults and cord blood.

Acetylcholinesterase↗
PubMed1991

Benefit from combining blood conservation measures in cardiac operations.

Conventional blood conservation techniques have been insufficient to decrease transfusion needs in increasingly complex cardiac operations. To evaluate combinations of conservation techniques, 300 patients were divided into three equal groups. Group 1 had intraoperative autotransfusion and return of mediastinal drainage for 4 hours postoperatively. Group 2 had these measures plus intraoperative plasmapheresis. These two groups were given a transfusion for a hematocrit of less than 0.21 on cardiopulmonary bypass. Group 3 was treated with the same measures as group 2 but did not receive transfusions while on pump unless the hematocrit decreased to less than 0.15. The percentage of patients in each group given transfusions in the operating room was 34% in group 1, 28% in group 2, and 7% in group 3 (p less than 0.05). The percentage of all patients receiving transfusions during hospitalization was 68% in group 1, 36% in group 2 (p less than 0.05), and 18% in group 3 (p less than 0.05). Average total units transfused were 2.16 +/- 0.25 in group 1, 0.7 +/- 0.15 in group 2 (p less than 0.05), and 0.37 +/- 0.07 in group 3 (p less than 0.05). The perioperative morbidity rates including myocardial infarctions and strokes were similar. There were no deaths in group 3. Combining complementary conservation measures is effective in reducing homologous blood transfusions, and the need for transfusion can be safely reduced by allowing profound hemodilution during bypass.

Aged↗
PubMed1991

Massive hemoptysis due to broncholithiasis.

Massive hemoptysis due to broncholithiasis is rare. Such a case is presented here, and the literature is reviewed. Surgical resection is the preferred definitive therapy, as a lack of bronchial artery collaterals limits the utility of bronchial artery embolization.

Aged↗
PubMed1990

Lung function in children following empyema.

Spirometry was performed and response to exercise was measured in 15 children following recovery from empyema to evaluate the impact of pleural infection on subsequent lung function. Seven children underwent chest tube drainage; eight did not. The two groups were similar in age (mean +/- SD, 6 +/- 5 years), sex distribution, bacterial pathogen-producing empyema, and age at follow-up evaluation (12 +/- 5 years). Only one child reported recurrent respiratory symptoms. No child had restrictive spirometric changes (total lung capacity, less than 80%; vital capacity, less than 80% predicted) but seven of 15 had a reduced forced expiratory volume in 1 second (less than 80% predicted) or forced expiratory flow during the middle half of the vital capacity (less than 75% predicted), suggesting mild airway obstruction. No child demonstrated reduced exercise tolerance due to restrictive ventilatory limitations. Mild obstructive abnormalities in lung function were identified with equal frequency in children treated with and without chest tube drainage.

Child↗
PubMed1990

Effects of intraoperative plasmapheresis on blood loss in cardiac surgery.

Intraoperative platelet-rich plasmapheresis allows autotransfusion of fresh, undamaged platelets and clotting factors at the completion of the operation. To evaluate this technology, we randomly assigned 100 consecutive patients who were to undergo an elective coronary bypass procedure and had normal clotting studies into the experimental (plasmapheresis) or the control group. Characteristics of both groups were similar, including average age (61.4 years versus 61.3 years [experimental versus control group]), sex (78% male versus 74% male), preoperative weight (80.9 kg versus 80.2 kg), preoperative red cell mass (1,989 mL versus 1,890 mL), perfusion time (102 minutes versus 106 minutes), and coagulation studies. Both internal mammary arteries were used in 68% of the patients. All patients had preoperative and postoperative blood volume determinations and complete clotting studies. Sixty-two variables related to bleeding were analyzed. Strict indications for transfusion were a hemoglobin level less than 7 g/100 mL in patients younger than 70 years and a hemoglobin level less than 8 g/100 mL in patients older than 70 years. The group receiving intraoperative plasmapheresis had a significant reduction in operative red cell mass loss (1,050 +/- 43 mL versus 1,226 +/- 61 mL; p = 0.021), a reduction in the average homologous transfusion (0.67 +/- 0.15 unit versus 1.8 +/- 0.25 units; p = 0.0002), and an increase in the percentage of patients not requiring blood transfusions (66% versus 32%; p = 0.001). This technique is useful in reducing postoperative blood loss and homologous transfusions.

Blood Coagulation↗
PubMed1990

Studies on the temporomandibular joints of an eighteenth-century London population (Spitalfields).

The mandibular condyles and glenoid fossae of 93 adult skulls of known age at death were studied in skeletons exhumed from the crypt of Christ Church, Spitalfields, London. Antero-posterior and mesio-lateral dimensions were recorded, as were the shapes together with form and surface changes. In addition, the teeth present and the extent of occlusal attrition were noted. There was sexual dimorphism in the mesio-lateral size of the condyle, and although ante-mortem tooth loss was higher than in previously studied Romano-British skulls, form and surface changes of the condyle were less marked. It is concluded that tooth loss is not the main factor involved in remodelling of the condyle.

Adolescent↗