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Biomedical subjects

S H Morgan

Publications and source records attributed to S H Morgan.

At least 19 recordsLinked to original sources
PubMed2005

Surface-enhanced Raman spectroscopy using silver-coated porous glass-ceramic substrates.

Surface-enhanced Raman scattering (SERS) has been studied using a silver-coated porous glass-ceramic material as a new type of substrate. The porous glass-ceramic is in the CaO-TiO2-P2O5 system prepared by controlled crystallization and subsequent chemical leaching of the dense glass-ceramic, leaving a solid skeleton with pores ranging in size from 50 nm to submicrometer. Silver was coated on the surface of the porous glass-ceramic by radio frequency (RF) sputtering or e-beam evaporation in vacuum. SERS spectra of excellent quality were obtained from several dyes and carboxylic acid molecules, including rhodamine 6G, crystal violet, isonicotinic acid, and benzoic acid, using this new substrate. This new substrate showed a good compatibility with these molecules. The porous glass ceramic with a nanometer-structured surface accommodated both test molecules and silver film. The absorbed molecules were therefore better interfaced with silver for surface-enhanced Raman scattering.

Benzoic Acid↗
PubMed1998

Cardiac troponins in patients with renal dysfunction.

Cardiac troponin T (cTnT) and cardiac troponin I (cTnI) were measured in 198 patients with renal dysfunction [132 men: median (range) age 66.1 (8.2-90.3) years]. cTnT was measured by two methods: ELISA and Enzymun (Boehringer Mannheim UK, Lewes, UK), both with a detection limit of 0.05 microgram/L in 179 and 78 patients, respectively. cTnI was measured in 80 patients by the OPUS plus and OPUS Magnum systems (Dade-Behring, Milton Keynes, UK) with a detection limit of 0.5 microgram/L. Patients were classified as having chronic renal impairment (CRI), chronic renal failure (CRF), acute renal failure including those with multiple organ failure on renal replacement therapy (ARF), and patients with chronic renal failure treated with haemodialysis (HD). Cardiac troponins were detectable in the serum of patients with renal dysfunction. cTnT was detectable in 113/179 (63.1%) and 33/78 (42.3%) by the ELISA and Enzymun methods respectively. cTnI was detectable in 17/80 (21.3%). cTnT (ELISA and Enzymun methods) and cTnI were detectable with increased frequency in the CRF, HD and ARF patient groups compared with the CRI group. Cardiac troponin concentrations did not correlate with serum creatine kinase (CK) activity, CK-MB, or urea or creatinine levels. Serial cardiac troponin measurements may be required to confirm or exclude a diagnosis of acute coronary syndromes in patients with renal dysfunction.

Acute Kidney Injury↗
PubMed1994

Ultrasound findings in renal parenchymal disease: comparison with histological appearances.

Ultrasound examination was carried out in 55 patients undergoing renal biopsy for suspected renal parenchymal disease. Analysis of sonographic and histological findings showed statistically significant positive correlations between renal size and the extent of glomerular hyper-cellularity and crescent formation and between cortical echogenicity and severity of glomerular sclerosis, crescent formation, interstitial inflammatory cell infiltration, tubular atrophy and interstitial fibrosis. Positive correlation was also observed between prominence of the medullary pyramids and glomerular sclerosis. The most marked sonographic abnormalities were seen in proliferative (including crescentic) glomerulonephritis, diabetic glomerulosclerosis and tubulo-interstitial nephritis. IgA, membranous and minimal change nephropathy were less likely to be associated with sonographic abnormalities. We conclude that certain sonographic appearances in renal parenchymal disease reflect the presence and severity of light microscopical abnormalities but, although ultrasound assessment provides a high positive predictive value for renal parenchymal disease, specific conditions cannot be distinguished.

Adult↗
PubMed1993

Cellular versus vascular rejection in transplant kidneys. Correlation of radionuclide and Doppler studies with histology.

The presence of two distinct subtypes of renal allograft rejection are well documented by histological studies. The differentiation between vascular rejection (VR) and cellular rejection (CR) is essential for proper management by avoiding the need for unnecessary and potentially harmful immunosuppressive treatment of VR. A histological pattern with features that are similar and confusable with some cases of rejection may be seen in cyclosporin A toxicity (CyT). To evaluate the efficiency of Guy's perfusion index (GPI) and the Doppler pulsatility index (DPI) in differentiating these two histological subtypes, a prospective study was designed in which a total of 140 radionuclide tests and 133 ultrasounds scans performed on the same day on 58 patients during the first 3 months post-transplant were analysed, and the results correlated with the histological findings of 84 renal biopsies. Results show that the GPI had a sensitivity of 86.5% and a specificity of 94% in differentiating VR and CyT from CR, while the DPI had values of 83% and 69%, respectively. Chi-squared analysis showed a higher significant association between the GPI and histology (P < 0.0001) compared to that of the DPI and histology (P < 0.005), while Youden's index (J) showed a significant difference (P < 0.05) between GPI and DPI. It is concluded that GPI is more sensitive and specific than DPI in differentiating transplants that are well perfused from those with poor perfusion (VR and CyT).

Adult↗
PubMed1993

Partial correction of dialysis-associated anaemia does not reduce erythropoietin dose or the incidence of side effects.

We examined the hypothesis that administering epoetin to maintain a lower target haemoglobin (Hb) results in a reduced side effect profile and a lower maintenance epoetin dose. We report a prospective study of 14 haemodialysis patients assessing epoetin dose efficiency and side effect profile of partially correcting dialysis-associated anaemia. Initial Hb was 6.2 +/- 0.6 g/dl (mean +/- 1 SD). Intravenous epoetin was commenced at 120 IU/kg/week in 3 divided doses and titrated to achieve a target Hb of 8 g/dl. Follow-up was 24 weeks. The final Hb was 8.7 +/- 0.8 g/dl. The peak epoetin dose was 196 +/- 86 IU/kg/week with a maintenance dose of 141 +/- 71 IU/kg/week. Therapy was associated with hypertension--5 patients (32%); seizures--1 patient (6%) (withdrawn from therapy), and temporary iron deficiency--4 patients (35%). Iron deficiency was corrected with oral therapy. There was 1 treatment failure. Comparable conventional regimens use 100-200 IU/kg to maintain the Hb at 10-13 g/dl and have a similar incidence of side effects. We concluded that reducing the target Hb in order to decrease epoetin requirements is not justified as it offers no benefit over conventional Hb targets in terms of dose requirements or side effects.

Adult↗
PubMed1993

Peritoneal dialysis catheters: a comparison between percutaneous and conventional surgical placement techniques.

Percutaneous peritoneal dialysis catheter (PDC) placement is a well-tolerated, rapidly performed side-room procedure that allows the rapid initiation of dialysis without the delay imposed in co-ordinating a surgeon, theatre time, and theatre staff. We retrospectively reviewed the clinical outcome of 230 PDC inserted over a 30-month period. Fifty were placed percutaneously (group P) and 180 were placed using conventional surgical techniques, 107 in patients commencing CAPD (group A) and 73 in patients commencing CAPD (group A) and 73 in patients previously established on CAPD (group B). Total experience accumulated was 2563 patient months: 270 patient months group P, 1381 patient months group A, 912 patient months group B. Percutaneous PDC insertion was non-elective, and reserved for patients unfit for general anaesthesia or haemodialysis. Group P patients were older (P < 0.001) and had increased early mortality (P < 0.005) due to underlying pathology. Death and early mechanical failure contributed to a shorter mean duration of catheter use in group P (9.0 +/- 2.3 months compared to 15.3 +/- 9.6 months group A and 17.3 +/- 9.7 group B) (P < 0.05). The peritonitis rate was similar in group P (1 per 6.75 patient months) and group B (1 per 7.4 patient months) but significantly lower in group A (1 per 15.7 patient months) (P < 0.01). We conclude that percutaneous PDC placement provides a safe, reliable access for peritoneal dialysis and is especially suitable for ill patients who would not tolerate general anaesthesia.

Catheterization↗
PubMed1991

Combined hepatic and renal transplantation in primary hyperoxaluria type I: clinical report of nine cases.

PURPOSE AND PATIENTS AND METHODS: The purpose of this article is to report the experience of three centers with combined hepatic and renal transplantation for pyridoxine-resistant primary hyperoxaluria type I (alanine:glyoxylate aminotransferase [EC 2.6.1.44] deficiency), with particular emphasis on the selection criteria and timing of the operation. Nine patients with this inherited disease were treated by combined hepatic and renal transplantation. The former replaces the enzyme-deficient organ while the latter replaces the functionally affected organ. RESULTS: One patient with gross systemic oxalosis died in the immediate postoperative period and another died 8 weeks postoperatively of a generalized cytomegalovirus infection, having shown evidence of biochemical correction. One patient with particularly severe osteodystrophy at the time of the operation died 14 months postoperatively from renal failure due to progressive calcium oxalate nephrocalcinosis involving the transplanted kidney, plus thromboembolic disease. He also had very extensive systemic oxalosis. An additional patient with severe osteodystrophy died 9 months postoperatively. One patient developed hyper-rejection of the kidney and died later of gastrointestinal hemorrhage. The four long-term survivors (22 to 38 months) have remained asymptomatic from the standpoint of their renal disease, with resolution of any manifestations of systemic oxalosis that they may have had. They are either employed or continuing their education. CONCLUSIONS: A prolonged period of end-stage renal failure treated by dialysis regimens that are suitable for non-hyperoxaluric renal failure and extensive systemic oxalosis, particularly oxalotic osteodystrophy, are poor prognostic features. We propose that hepatic transplantation should be considered as definitive treatment before end-stage renal failure develops. This should be supplemented by renal transplantation with vigorous pre- and perioperative hemodialysis to deplete the body stores of oxalate. Although some authorities would reserve hepatic transplantation for patients in whom renal transplantation has failed, we suggest that combined liver and kidney transplantation is appropriate in patients who have never had a renal graft. Furthermore, the time has come to consider hepatic transplantation before any irreversible renal damage has occurred in these patients.

Adolescent↗
PubMed1990

Changes in antischistosomal drug usage patterns in rural Qalyubia, Egypt.

To investigate the usage of antischistosomal drugs in the Nile Delta, an antischistosomal drug history was obtained by interview from a sample of inhabitants of the villages of Halaba (1,024, or every 4th household) and Kharkania (505, or every 20th household), south-central Nile Delta. Only 3% and 0.4% of participants, respectively, in the 2 villages reported receiving antischistosomal drugs during the previous 4 years. Most villagers received oral compounds (praziquantel and niridazole), and the treatment regimen was completed by 95%. This study reveals changes in antischistosomal drug usage since a study 8 years earlier in the village of Halaba, when most of the drugs were injectable compounds.

Administration, Oral↗
PubMed1990

The neurological complications of Anderson-Fabry disease (alpha-galactosidase A deficiency)--investigation of symptomatic and presymptomatic patients.

Anderson-Fabry disease is an X-linked inborn error of metabolism characterized by subnormal activity of the lysosomal hydrolase, alpha-galactosidase A. We have assessed the incidence and nature of neuropathy in 12 patients (seven affected men and five carrier females). Abnormalities of cutaneous thermal sensation were common, even in asymptomatic carriers, with a unique predilection for cold sensitivity which suggests involvement of small myelinated nerve fibres. Intracranial abnormalities were frequently detected by magnetic resonance imaging (MRI) in males, both with and without overt cerebrovascular disease, and were more extensive in older patients. Such abnormalities were not detected in carriers. Auditory and vestibular abnormalities were present in six patients, only one of whom was symptomatic. Cranial MRI and assessment of cutaneous thermal thresholds are sensitive techniques which can identify neurological involvement in asymptomatic patients. They may be of benefit in monitoring the effectiveness of enzyme replacement therapy and excluding the carrier state for the defective gene.

Adolescent↗