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Biomedical subjects

J M Guy

Publications and source records attributed to J M Guy.

At least 19 recordsLinked to original sources
PubMed2003

Evaluation of a prison outreach clinic for the diagnosis and prevention of hepatitis C: implications for the national strategy.

BACKGROUND: Hepatitis C virus (HCV) infection is a major public health problem recognised by the UK National Strategy that proposes that a care pathway for assessment, diagnosis, and treatment be established in all prisons, integrated within managed clinical networks. A prison sentence provides the opportunity to focus on traditionally hard to reach patients. AIMS: To evaluate the prevalence of HCV infection in a UK prison cluster and to assess the effectiveness of a prison outreach service for hepatitis C. SUBJECTS: Male prisoners. METHODS: A nurse specialist led clinic within a cluster of adult prisons was established, offering health education on hepatitis C, advice on harm minimisation, and HCV testing. Infected prisoners were offered access to a care pathway leading to treatment. Outcome measures were uptake of the service, and diagnosis and treatment of hepatitis C. RESULTS: A total of 8.5% of 1618 prisoners accepted testing: 30% had active infection with HCV. Most were ineligible for treatment due to psychiatric illness or did not receive treatment for logistic reasons. Injecting drug use was the major risk factor in all cases. Only 7% of HCV polymerase chain amplification positive inmates received treatment in prison. CONCLUSION: There is a large pool of HCV infected prisoners at risk of complications, constituting a source of infection during their sentence and after discharge. A prison outreach clinic and care pathway was perceived as effective in delivering health education, reducing the burden on prison and hospital services. It provided an opportunity for intervention but had a limited effect in eradicating HCV in prisoners and it remains unclear how this might be achieved.

Adult↗
PubMed1999

Hypophosphataemia in general practice patients.

We compared plasma phosphate concentrations in general practice patients and hospital inpatients and outpatients over an 8-month period. The distribution of results in all three groups was similar and 12-16% of results were at or below 0.8 mmol/L. In general practice patients, 8.3% of results from males and 12.1% from females were below the lower limit of their respective reference ranges. Eighteen of these patients (0.2% of results) had plasma phosphate concentrations < or = 0.4 mmol/L. On follow-up, only two of these patients had any attributable cause for their severe hypophosphataemia; in the remainder, it was unexpected and unexplained. Hypophosphataemia in outpatients and general practice patients is more common than has previously been appreciated. We present a strategy for further investigation of these patients.

Adult↗
PubMed1997

Comparison of lactate and bicarbonate buffered haemofiltration fluids: use in critically ill patients.

OBJECTIVE: To compare acid-base balance, lactate concentration, and haemodynamic and O2 transport variables during haemofiltration with replacement fluid containing 44.5 mmol/l Na+ lactate or 40 mmol/l Na+ HCO3- and 3 mmol/l lactic acid. DESIGN: A prospective, randomized trial. SETTING: A multidisciplinary, adult intensive care unit in a university hospital. PATIENTS: Forty acidotic patients who required haemofiltration, were dependent on mechanical ventilation, and had PA catheters in situ. INTERVENTIONS: During haemofiltration patients received lactate or bicarbonate replacement fluid at a mean rate of 1.7 l/h (SD 0.3). Arterial blood gases, plasma lactate, and haemodynamic and O2 transport variables were measured before and after 12 and 24 h haemofiltration. Ultrafiltrate was collected for lactate estimation. MEASUREMENTS AND MAIN RESULTS: As means (SD). The net gain of lactate was 63 mmol/h (12 mmol) with Na+ lactate and 0 mmol/h (0.3 mmol) with Na+ HCO3-. There was a significant increase in pH and [lactate] in both groups, but [lactate] was higher in patients receiving lactate. Twenty-one patients survived to ICU discharge, these patients were significantly less acidotic after filtration (lactate group: 0 h: pH 7.23 (0.09), [lactate] 2.4 mmol/l (1.7); 12 h: pH 7.34 (0.09), [lactate] 4.7 mmol/l (2.4); 24 h: pH 7.36 (0.07), [lactate] 4.7 mmol (2.7). HCO3 group: 0 h: pH 7.23 (0.09), [lactate] 2.3 (1.3); 12 h: pH 7.32 (0.06), [lactate] 2.9 mmol/l (1.8); 24 h: pH 7.35 (0.08), [lactate] 2.8 mmol/l (2.0). Base deficit: survivors: 0 h: 9 mmol/l (4); 12 h: 2 mmol/l (3). Non-survivors: 0 h: 10 mmol/l (3); 12 h: 6 mmol/l (3)). Haemodynamic and O2 transport variables were not significantly affected by treatment group or outcome. CONCLUSIONS: The degree of correction of acidosis during the first 24 h of haemofiltration was determined by patients outcome but was not affected by the substitution of bicarbonate- for lactate-containing replacement fluids.

Acidosis↗
PubMed1997

Urinary excretion of albumin and retinol binding protein in systemic lupus erythematosus.

We have measured the urinary excretion of total protein, albumin and retinol binding protein (RBP) in random urine specimens obtained from 40 female patients with systemic lupus erythematosus (SLE). Thirty-three of these patients had no clinical evidence of any renal impairment (non-renal SLE); seven had overt renal disease (renal SLE). RBP:creatinine ratios were significantly higher in non-renal SLE patients compared with female controls (P = 0.002). There was no significant difference between urine total protein concentrations, albumin:creatinine or total protein:creatinine ratios in non-renal SLE patients when compared with controls, despite approximately 20% of these patients having elevated excretion of total protein or albumin. All seven renal SLE patients had elevated albumin:creatinine ratios but only four of them had an increased RBP:creatinine ratio. Of 29 non-renal SLE patients who had urinary total protein concentrations below 0.2 g/L, (i.e. approximating to a negative protein dipstick), 14 had increases in either albumin or RBP:creatinine ratios. Only two patients had increases in both. In the absence of clinical evidence of renal disease, increases in urinary albumin or RBP excretion could indicate subclinical nephropathy and measurements may have a role in the early diagnosis and subsequent monitoring of renal disease in SLE.

Adult↗
PubMed1996

[Periaortic fibrosis with pericardial and perirenal involvement: apropos of a case].

The authors report a case of right ventricular insufficiency by constrictive pericarditis revealing aortic and retroperitoneal fibrosis. Only one similar case has been published. We discuss the etiology of this affection, the possible analogies with idiopathic systemic fibrosis and Takayasu's disease and the possible participation of thyroiditis disease and therapy (particularly propranolol).

Female↗
PubMed1996

Creatinine and urea clearance during continuous veno-venous haemofiltration in critically ill patients.

Urea and creatinine clearances achieved using continuous veno-venous haemofiltration were calculated in 16 critically ill patients, during 50 episodes of filtration. The effects of filter life and the volume of ultrafiltrate on these clearances were also evaluated. Clearances were calculated from urea and creatinine concentrations in blood and ultrafiltrate and the volume of ultrafiltrate produced. The overall mean (SD) urea clearance was 26.6 (6.0) ml.min-1 and the overall creatinine clearance was 30.1 (6.3) ml.min-1. The mean (SD) ultrafiltrate production was 29.6 (5.9) ml.min-1. Creatinine clearance was significantly lower in filters that failed within 24 h (filters < 24 h 27.5 (6.3) ml.min-1; filters > 24 h 32.2 (5.5) ml.min-1). The clearance of both solutes increased with increasing ultrafiltrate volume (p < 0.001). We conclude that satisfactory clearance of urea and creatinine can be achieved using continuous veno-venous haemofiltration. Increases in ultrafiltrate production lead to similar increases in urea and creatinine clearance. Prolongation of filter life may improve creatinine clearance.

Acute Kidney Injury↗
PubMed1995

[Myocardial infarction following rapid perfusion of corticoids].

The authors report the case of myocardial infarction occurring immediately after rapid intravenous infusion of a high dose of corticosteroids prescribed for a relapse of multiple sclerosis. Ventriculography confirmed the myocardial damage but the coronary arteries were normal. An aetiological investigation was negative. The authors review the cardiac secondary effects which may be very serious and even fatal. Coronary insufficiency is rare (only 3 previously published cases); it is therefore difficult to determine the prognosis. The possible mechanisms of infarction are discussed. Finally, the authors underline the importance of recording an ECG before treatment, of ECG monitoring during the infusion, and the need for repeating the recordings and of prolonging hospital admission when necessary.

Female↗
PubMed1994

Carotid surgery in the octogenarian.

The records of 52 patients aged 80 years or older who underwent 56 carotid artery reconstructions were analyzed retrospectively. Four patients had amaurosis fugax, 27 patients had experienced one or more transient ischemic attacks, eight had a completely or partially reversible stroke, and 10 had vertebrobasilar insufficiency. Three patients were asymptomatic. Arteriograms documented stenosis > 80% on the operated side in 48 cases, whereas the contralateral carotid artery was occluded or had > 80% stenosis in 10 cases each. Two or more cerebral arteries were involved in 37 patients. CT scans were normal in only 21 (40%) patients. General anesthesia was used in 54 of 56 operations. Thirty-six endarterectomies, 18 bypasses, and two resection-anastomoses (for tortuosity) were performed. A shunt was employed in eight (14.3%) cases. One lethal stroke (1.9%) occurred during the first postoperative month. Three patients experienced nonfatal strokes, two of which gave rise to residual deficits. Two patients were lost to follow-up. For the remaining 49 patients the mean follow-up was 24 months. Two-year actuarial survival was 76.3% for the entire series and 67% for those surviving without neurologic events. This study shows that when properly selected the elderly population can safely undergo carotid surgery.

Aged↗
PubMed1994

Retinol binding proteinuria and phosphaturia: markers of paracetamol-induced nephrotoxicity.

The occurrence of hypophosphataemia in paracetamol overdose suggests that nephrotoxicity is common, impaired renal tubular reabsorption of phosphate indicating renal damage. To investigate the potential nephrotoxicity of paracetamol, we studied 148 consecutive patients with paracetamol overdose. Serial clinical and biochemical measurements were made, and a fasting overnight urine collection was obtained for creatinine (Cr), phosphate and retinol-binding protein (RBP) determination. Renal threshold phosphate concentration (TmPO4/GFR) was determined from urinary parameters by an established nomogram. The degree of hypophosphataemia correlated with the severity of overdose, and with TmPO4/GFR. The median RBP/Cr ratio was higher in those patients exhibiting biochemical hepatotoxicity compared with those without hepatotoxicity, in whom median RBP/Cr was not significantly higher than controls. Within the group of patients showing biochemical hepatotoxicity, there was a correlation between log RBP/Cr and TmPO4/GFR. RBP/Cr ratio is a less sensitive marker of renal tubular toxicity than phosphaturia in these patients, and may indicate a different mechanism of toxicity.

Acetaminophen↗
PubMed1994

[Left main coronary artery disease].

There are many causes of left main coronary artery disease, the first of which is atherosclerosis. Other rarer causes may be observed, such as acute and chronic occlusions, spasm and primary and secondary dissection. The prevalence of stenosis of the left main coronary artery at coronary angiography is about 5%. The risk factors are the same as for coronary artery disease. The symptoms are angina, especially unstable angina. The diagnosis is suspected on the finding of an extremely positive exercise stress test, confirmed by coronary angiography. The results of the prospective large scale Veterans Administration trial showed surgery to be the treatment of choice with a 30 months survival of 80% in the surgical group compared with 64% in the medical group. The operative morbidity and mortality is less than 10% at present. Recent studies have reported a medium-term mortality of 4.3 to 10.25% with follow-up periods of 24 and 43 months respectively. The long-term survival and functional improvement are excellent, with values of nearly 80%. Chronic occlusion of the left main stem is rare, 0.01 to 0.7% in coronary angiographic studies. There is no difference in presentation, electrocardiographic or stress test features compared with other severe coronary artery disease. The diagnosis is angiographic and the treatment surgical because of the mediocre natural history with risks of sudden death and severe infarction. Acute occlusion of the left main coronary is rare for generally fatal. The mechanism is acute thrombosis and the clinical presentation is that of extensive infarction usually with cardiogenic shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Anesthesia and general surgery in cardiac patients].

Close cooperation is necessary between the cardiologist and anesthesiologist preoperatively in order to identify the risks associated with a surgical procedure. This article reviews the various types of anesthesia and their effects on the cardiovascular system, in particular in relation to the category of cardiovascular disease. Accurate definition of the operative risk involves thorough evaluation of three essential parameters: cardiovascular status, the type of surgery and the type of anesthesia. These high-risk patients require management not only pre- and peroperatively, but also postoperatively, which is the period when the majority of complications occur. Mention is also made of drug interactions between anesthetic and cardiovascular agents.

Anesthesia, General↗
PubMed1993

Myocardial infarction and nicotine patch: a contributing or causative factor?

A case of angina pectoris revealed by nicotine patch treatment is described in a patient who continued to smoke and subsequently suffered a myocardial infarction. The various side effects of nicotine and its derivatives are recalled. The action of nicotine on coronary vasomotricity and its mediators is discussed.

Administration, Cutaneous↗
PubMed1993

Urinary retinol binding protein: stability and pre-analytical handling of specimens for its measurement.

The stability of retinol binding protein (RBP) in urine has been reassessed and was found to be pH-dependent, diminishing as urinary pH decreased. When urines were incubated at 4 degrees C for 1 week, statistically significant losses of RBP were observed at pH values less than seven, varying in degree in different urines. At 37 degrees C some urine specimens showed minor losses when incubated for periods up to 4 h. This was more marked at pH 5 than pH 7 with maximum losses of 26% and 12%, respectively. When adjusted to pH 7, urines showed no significant loss of RBP when stored at 4 degrees C for up to 2 weeks; at -20 degrees C no significant change in RBP concentration was found for at least 14 weeks. To minimize losses of RBP it is recommended that urine pH is adjusted to above seven immediately after voiding.

Enzyme-Linked Immunosorbent Assay↗
PubMed1993

[A rare cause of loss of consciousness: mastocytosis. Apropos of 3 cases].

The authors report three cases of syncope due to systemic mastocytosis. This is a rare cause of syncope but should be recalled in certain circumstances. In the light of these cases, the authors review the literature with respect to this unusual presentation. Syncope may occur at any age. Loss of consciousness may be more or less complete, brief or prolonged, isolated or recurrent and usually accompanied by prodromal symptoms. The least controversial physiopathogenic mechanism of these syncopes is intense vasoplegia induced by the release of vasoactive mediators, especially histamine. When there is a clinical suspicion of mastocytosis, even in the absence of skin changes, the diagnosis is confirmed by biopsy which shows abnormally high numbers of mastocytes irrespective of the organ biopsied. The treatment of acute forms with collapse is based on intravenous infusion of macromolecular fluids and injections of epinephrine. Prevention is by drugs which inhibit the synthesis of histamine, the degranulation of mastocytes and the production of prostaglandin D2.

Aged↗
PubMed1993

[Painless infarction in antiphospholipid syndrome].

The authors report a rare case of myocardial infarction secondary to coronary thromboses caused by the antiphospholipid syndrome. The relations between the cardiac pathology, especially the coronary disease, and antiphospholipid antibodies are recalled. The importance and methods of monitoring the anticoagulant therapy are emphasised.

Anticoagulants↗