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Biomedical subjects

N A Jones

Publications and source records attributed to N A Jones.

At least 55 records · Page 3Linked to original sources
PubMed1992

Changes in the phosphorylation status of a 19 kD cytosolic protein are linked to the growth arrest of HL-60 cells.

A major 19 kD cytosolic protein (p19) has been described in a number of cell systems with respect to its rapid phosphorylation when protein kinase C is activated and has been proposed as a key substrate of this enzyme. Phosphorylation of p19 occurs when the growth of cells is affected by 12-O-tetradecanoylphorbol-13-acetate (TPA) and it has been proposed that increased phosphorylation of p19 relates to the cessation of cell growth. This study delineates precisely the relationship between p19 phosphorylation changes in the growth and differentiation status of cells. Changes in the levels of two phosphorylated forms of p19 were assessed in HL-60 promyelocytic cells and a variant HL-60 cell line which stopped growing and differentiated in response to TPA and were compared to changes seen in HL-60 variant lines which merely growth arrested when treated with TPA. In lines which either did or did not differentiate, in response to TPA, the p19 protein was rapidly and transiently phosphorylated. Thus, this alteration in the phosphorylation status of p19 is associated with the process of growth arrest and not related to the onset of cell differentiation. The p19 protein and the enzymes which effect its phosphorylation status modulate the growth of cells and possible disregulation of p19 and/or its kinases and phosphatases is of interest as regards the leukaemic transformation of cells.

Cell Differentiation↗
PubMed1992

Electroencephalogram asymmetry during emotionally evocative films and its relation to positive and negative affectivity.

The purpose of the present study was to determine if there were differences in hemispheric lateralization during the experience of emotions and if those differences were related to personality style. College-age adult subjects selected for high positive and negative affectivity on Tellegen's Multidimensional Personality Questionnaire (MPQ; Tellegen, 1982) viewed video stimuli selected for their emotionally evocative nature and rated the intensity of the emotions they experienced. The ongoing electroencephalogram (EEG) was recorded while they watched the video clips. Analyses of the EEG data revealed that there were differences in regional activation during the emotional video clips, especially for those stimuli selected to elicit either happy or disgust emotions. These results support the hypothesis that the right hemisphere is specialized for the experience of certain negative affects, whereas the left hemisphere is specialized for the experience of certain positive affects. The findings also indicated some support for the theory that individual differences in personality style are related to differing levels of hemispheric arousal.

Adolescent↗
PubMed1991

The specificity of technetium-labelled-leucocyte imaging of aortic grafts in the early postoperative period.

Radio-labelled-leucocyte imaging is becoming accepted as the investigation of choice when infection of prosthetic arterial bypass grafts is suspected. However, alternative sources of inflammation, such as haematoma and, perhaps, the healing and incorporation of newly inserted bypass grafts, are potential causes of false positive results. This study examines the use of technetium-labelled-leucocyte imaging during the postoperative in-hospital period following aortic bypass surgery. Two labelled-leucocyte scans were carried out serially in 20 patients randomly allocated to receive either of two types of Dacron aortic graft in regular use. The earlier scans were undertaken at 2-5 days after surgery and only two of these scans were positive. None of the later scans, undertaken at 7-10 days after surgery, was positive. None of the patients had a graft injection as evidenced by clinical features, leucocyte counts, and C-reactive protein measurements. These results suggest that recent surgery does not in itself significantly reduce the specificity of technetium-labelled-leucocyte imaging.

Aged↗
PubMed1990

New isotopic technique for detecting prosthetic arterial graft infection: 99mTc-hexametazime-labelled leucocyte imaging.

Early and accurate detection of prosthetic arterial graft infection is important because this serious complication of vascular surgery carries high morbidity and mortality rates. This report describes the use of a new method of isotopic imaging to detect graft infection using 99mTc-hexametazime-labelled leucocytes. Seventeen patients with potentially infected arterial grafts were imaged in addition to routine investigations but were managed according to our normal surgical practice. 99mTc-imaging was positive in eight patients with proven graft infection and falsely positive in one patient with a groin haematoma (89 per cent specificity). There were no false negatives (100 per cent sensitivity) after an average follow-up of 6 months (range 3-9 months). This technique has proved a reliable and rapid method of confirming graft infection.

Aged↗
PubMed1987

Lateral paramedian incision.

Prospective randomization of 360 patients undergoing abdominal surgery determined whether a standard lateral paramedian incision was made (group A) or one of two modifications in which the anterior sheath was incised medially and posterior sheath incised laterally (group B) or vice versa (group C), in order to determine the necessity for incising both layers laterally to provide the shutter mechanism which is held responsible for the integrity of this wound. Medial incision of the anterior rectus sheath significantly reduced the time required to perform the incision (P less than 0.02) and tended to reduce wound sepsis rate. However, this was achieved at the cost of a higher incisional hernia rate (0 per cent, 2.9 per cent and 4.6 per cent in groups A, B and C respectively, P less than 0.02). We conclude that lateral incision of both anterior and posterior rectus sheath is necessary to obviate the risk of wound hernia with the lateral paramedian incision.

Abdomen↗
PubMed1986

Delorme's operation: the first choice in complete rectal prolapse?

The Delorme operation has been used to treat 27 consecutive patients with complete rectal prolapse. The mean age in this group was 74 years and the average length of the prolapse was 12 cms. There was no postoperative mortality or morbidity. The follow-up ranges from 11 months to 64 months (mean 35 months) and so far there have been two recurrences. One of these has been successfully treated by a second Delorme operation. The second patient has declined further surgery. This low recurrence rate combined with the minor nature of the procedure suggests that the Delorme operation should be considered in all patients presenting with complete rectal prolapse.

Adult↗
PubMed1982

A double-blind trial of suloctidil v. placebo in intermittent claudication.

In a recent double-blind trial lasting over 6 months, 40 patients suffering from intermittent claudication were randomly allocated to receive 300 mg of suloctidil per day or exactly matching placebo capsules. In addition to treadmill walking distance, other objective criteria including ankle blood pressure response and muscle blood flow measured by 133Xe clearance were used to assess the effectiveness of therapy. Nine patients (4 in the suloctidil group and 5 controls) did not complete the trial according to the protocol. Of the remaining 31 patients, 17 were in the control group and 14 received suloctidil. A significant improvement in the absolute walking distance, the level of beta-thromboglobulin (beta TG) compared to pre-therapy value and the time for the ankle pressure index to return to the pre-exercise value was observed in patients receiving suloctidil.

Adult↗
PubMed1981

Ultrasonographic determination of lumbar spine angulation.

Abdominal ultrasonograms of recumbent, supine adult subjects were used to measure the angle formed between the horizontal plane and a plane along the anterior border of upper lumbar vertebral bodies. The angle, referred to as phi, for male and female subjects averaged 8.8 degrees. When this angle was compared in subjects with the hips flexed and extended, there was no significant difference. There was a significant difference between subjects in a recumbent position and a standing position. The amount of angulation was compared to the age of the individual and found to have a low correlation coefficient. The angle phi appears to be a good indicator of the amount of lordosis, it related well to previous methods of measuring lordosis, and it is a benign procedure in a genetically sensitive region.

Adult↗
PubMed1981

Enhanced in vivo platelet release reaction and malondialdehyde formation in patients with hyperlipidemia.

Plasma level of beta-thromboglobulin (beta TG), a useful marker of in vivo platelet "release reaction,"was determined by radioimmunoassay in 69 patients, with three types of primary hyperlipidemia (IIa, IIb, IV) and compared with the findings in age- and sex-matched healthy controls and 57 patients with established atherosclerosis and peripheral vascular disease. Malondialdehyde (MDA) formation, used for assessment of prostaglandin synthesis, was determined in 51 and plasma platelet factor 4 (PF4), measured by radioimmunoassay, in 48 of the patients with hyperlipidemia. Results were correlated to five serum lipids and lipoprotein levels in the patients with hyperlipidemia. beta TG was significantly increased in the patients with hyperlipidemia and peripheral vascular disease, compared to those in the controls (p < 0.001); it was significantly higher in the patients with hyperlipidemia than in those with peripheral vascular disease. PF4 and MDA formation were also increased in the patients with hyperlipidemia, and significantly higher levels of MDA were obtained in patients with type IIb and type IV hyperlipidemia than in those with type IIa hyperlipidemia (p < 0.02). beta TG and MDA correlated weakly with total serum cholesterol triglycerides and very low density lipoprotein-triglyceride. There was also a significant correlation between beta TG and PF4, and MDA production. These results indicate that in vivo platelet "release reaction" and MDA formation are increased in hyperlipidemic patients. The release reaction is more enhanced in those with hyperlipidemia than in the patients with peripheral vascular disease. They suggest that the abnormal platelet function is related to the elevated levels of serum lipids and lipoproteins in the hyperlipidemic patients and not only to the atherosclerotic changes associated with hyperlipidemia.

Aged↗
PubMed1981

Platelet function in diabetes mellitus in relationship to complications, glycosylated haemoglobin and serum lipoproteins.

Mean levels of beta-thromboglobulin and platelet factor 4 were highly significantly elevated in diabetes compared to controls (72.6 v. 36.3 ng/ml, P less than 0.0005; 48.5 v. 16.5 ng/ml, P less than 0.0005; respectively) as was malondialdehyde formation (12.4 v. 8.1 nmol/10(9) platelets, P less than 0.0005). Diabetes with retinopathy had significantly higher levels of beta-thromboglobulin than those without retinopathy (79 v. 70 ng/ml; P less than 0.042). However, those diabetics without clinical evidence of vascular disease had levels of beta-thromboglobulin and platelet factor 4 significantly higher than controls. beta-Thromboglobulin did not correlate with glycosylated haemoglobin but did correlate significantly with individual lipid and lipoprotein levels (beta-thromboglobulin v. total triglyceride, P less than 0.029; v. VLDL triglyceride, P less than 0.041; v. LDL cholesterol, P less than 0.042; v. HDL/total cholesterol ratio, P less than 0.02). Abnormal platelet function may contribute to the vascular complications of diabetes mellitus.

Beta-Globulins↗
PubMed1980

A physiological study of elastic compression stockings in venous disorders of the leg.

The physiological effects of elastic compression stockings on venous disorders of the leg have been studied in three groups of 10 patients. These patients were divided by examination and ascending venography into those with: (a) a normal venous system in the leg, (b) superficial varicose veins and (c) a post-phlebitic limb. In a randomized cross-over trial each groups wore Eesiness NHS two-way stretch or Sigvaris medium compression below-knee stockings for three weeks. In the post-phlebitic limb group a further comparison was made with Sigvaris strong compression below-knee stockings after a 6-week rest period. The effects were objectively compared using foot volumetry and sodium (24Na) subcutaneous tissue clearance. The physiological benefits of Sigvaris medium and strong compression stockings were comprehensively demonstrated by both methods of assessment in patients with the post-phlebitic limb. Benefit from Sigvaris medium compression stockings was also demonstrated in the patients with varicose veins. In the group with normal veins there were negligible physiological benefits from compression stockings. Eesiness stockings failed to produce a significant physiological effect in each group.

Clothing↗
PubMed1980

Height of the tarsus of the lower eyelid.

The vertical height of the lower eyelid tarsus of 20 patients submitting to lower eyelid resections and the lower tarsus of 17 cadavers was 3.7 mm (+/- 0.3) and 3.9 mm (+/- 0.5), respectively. The average value found in our patients was statistically different (P less than .05) than the values of 5 to 7 mm reported previously. The lower tarsus should be clearly identified in procedures involving eyelid repair or eyelid reconstruction so that tension-bearing sutures can be placed through the tarsus.

Adult↗