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Biomedical subjects

S C Harris

Publications and source records attributed to S C Harris.

At least 19 recordsLinked to original sources
PubMed1992

Thyroid and parathyroid surgical complications.

Ninety-five thyroid and 19 parathyroid patients underwent 114 operations over the past 10 years. Total thyroidectomy was the preferred procedure. There were no recognized injuries to the external branch of the superior laryngeal nerve. Five recurrent laryngeal nerve injuries occurred, but only one was clinically significant. Most injuries (three of five) occurred during lobectomies. One injury occurred during a total thyroidectomy, and one occurred during a completion thyroidectomy. No patients developed permanent hypoparathyroidism. The nerve injury rate was 1%, and the hypoparathyroidism rate was 0% for 114 operations.

Female↗
PubMed1992

Assay of fluconazole by high-performance liquid chromatography with a mixed-phase column.

A mixed-phase liquid chromatographic column was used to assay fluconazole in plasma, serum, and cerebrospinal fluid. The assay was linear from 0.2 to 20 micrograms/ml, with an average coefficient of variation of less than 5%. The partitioning of the drug between serum and cerebrospinal fluid was determined for 34 patients. The method was demonstrated to be suitable for both pharmacokinetic studies and monitoring of patients receiving treatment with this antifungal agent.

Chromatography, High Pressure Liquid↗
PubMed1992

Pharmacokinetics of quinidine in male patients. A population analysis.

Quinidine pharmacokinetic behaviour was evaluated in 139 adult hospitalised men receiving oral quinidine therapy. A total of 391 serum quinidine concentrations were measured by enzyme immunoassay for routine clinical purposes. The NONMEM programme was used to examine the relationship between quinidine pharmacokinetics and several potential covariates. A 1-compartment open model with first-order absorption and elimination was assumed. The mean apparent volume of distribution (Vd) was about 230L. When measured, alpha 1-acid glycoprotein (AAG) levels were not included in the analysis. Oral quinidine clearance (CL) decreased with age, severe congestive heart failure and renal disease, and increased in patients with a history of alcohol abuse. The interpatient variability in CL and the intrapatient residual variability expressed as coefficients of variation (CV) were 28 and 31%, respectively. When AAG values were incorporated into the analysis, the only important covariates of CL were the AAG measurements and the presence of renal dysfunction as indicated by a calculated creatinine clearance of less than 50 ml/min (3 L/h). The interpatient variability in CL and the residual intrapatient CVs decreased to approximately 24 and 26%, respectively. Improvement of the CL model by inclusion of measured AAG strongly suggests that quinidine elimination is dependent on the free concentration of drug in plasma and supports the use of free serum quinidine concentrations when evaluating and monitoring quinidine therapy.

Aged↗
PubMed1992

Primary lymphoma of the thyroid, the association with Hashimoto's thyroiditis.

This paper reviews the cases of thyroid lymphoma seen at one centre to assess the relationship between autoimmune thyroiditis and the subsequent development of thyroid lymphoma. Twenty two cases of thyroid lymphoma were seen over a 10 year period; 5/22 (23%) had previously been diagnosed as having Hashimoto's thyroiditis. The series comprised 18 women and four men; mean (range) age at presentation was 64 (26-85) years. All patients presented with a rapidly enlarging goitre and 13/22 (59%) underwent surgical excision prior to diagnosis of lymphoma. Nineteen of 22 (86%) patients underwent radiotherapy. The 5-year mortality for stage IE disease was 43%, survival appeared to be unrelated to previous Hashimoto's thyroiditis or to surgical resectability. The histological differentiation between pre-existing thyroiditis and thyroid lymphoma is often difficult and may lead to an underestimate in the reporting of the association. A prospective study of serial autoantibody assays in patients with Hashimoto's thyroiditis may be useful in predicting the onset of lymphomatous change in this condition.

Adult↗
PubMed1991

Assessment of osteopenia at autopsy.

Osteoporosis is a common problem for the pathologist in the elderly female population where pathological fractures particularly of the neck of femur are frequent. Yet how should we assess osteoporosis at autopsy? This study reports on autopsy assessment of osteopenia, comparing our subjective findings of rib fracturability and vertebral compressibility with histological and histomorphometric assessment on a bone biopsy. We have shown a poor correlation between gross autopsy and histological techniques. There is good correlation between two gross autopsy techniques and these methods have been shown to be reproducible between observers. We believe that the most useful test of whether a patient's bones are likely to break is to assess the fracturability of the ribs (and possibly the vertebral bodies) at autopsy. This should be supplemented with undecalcified histology sections from the iliac crest where possible. Further studies are clearly warranted in this area.

Aged↗
PubMed1991

Assessment of osteoporosis at autopsy: mechanical methods compared to radiological and histological techniques.

Osteoporosis is a common problem in the elderly female population and pathological fractures are a frequent complication, but how should the pathologist assess the severity of the disease at autopsy? In this study we have compared subjective, semi-quantitative assessments of rib fracturability, vertebral compressibility, Singh index and histomorphometric methods against a 'gold standard' assessment, namely the force required to fracture the femoral neck. We have shown good correlations between rib fracturability. Singh index and the standard chosen. Poor correlation was shown between histomorphometric techniques and the standard. Our findings suggest that gross rib fracturability is a good indicator of osteoporosis in as far as bone fragility is an indicator of the severity of osteoporosis. However, as the population under examination was small, further studies in this area are clearly warranted in order to extend these findings.

Aged↗
PubMed1990

The association between thyroid neoplasia and intestinal polyps.

Recent reports have suggested an association between familial adenomatous polyposis and papillary carcinoma of the thyroid. This report describes four patients, each with intestinal polyps and thyroid or thyroglossal cyst carcinoma. One patient had a medullary rather than papillary carcinoma of the thyroid and in another the intestinal polyps were due to Peutz-Jeghers syndrome. This may indicate a wider association between thyroid carcinoma and intestinal polyps than has previously been recognised.

Adult↗
PubMed1989

Immunohistochemistry and lectin histochemistry in sarcomatoid renal cell carcinoma: a comparison with classical renal cell carcinoma.

We investigated the expression of various cell markers in renal cell carcinoma, concentrating particularly on the sarcomatoid variety, using lectin and immunohistochemical techniques. The sarcomatoid variant showed stronger staining in a higher proportion of cases for vimentin and reduced positivity for epithelial membrane antigen, in comparison with classical renal cell carcinoma. All sarcomatoid tumours reacted with at least one cytokeratin, enabling them to be distinguished from true renal sarcomas; this is of diagnostic value when a panel of markers is used. Overall a similar pattern of markers is seen in sarcomatoid and classical renal cell carcinoma using lectin and immunohistochemistry, suggesting that the sarcomatoid variant arises as a metaplastic change rather than having a different histogenesis.

Carcinoma↗
PubMed1989

Microassay for prostatic androgen receptors correlated with quantitative histological assessment.

A new microassay in which cryostat sections of prostate tissue were used to provide the source of soluble androgen receptor for biochemical assay, was devised using an isoelectric focusing method, with [3H]-mibolerone as the androgenic radioligand. Adjacent cryostat sections from the same tissue block were stained for diagnostic and quantitative histological assessment. The assay was used to illustrate variations in tissue androgen receptor concentration for correlation with epithelial cell content in benign prostate hyperplasia and prostatic cancer, and to show the effects of androgen receptor concentration of resection of prostatic tissue by electroresection. The results indicate that the heat in electroresection renders prostatic tissue unsuitable for androgen receptor assays, and suggest that knowledge of the cellular composition of carcinomatous prostates may be of importance in the full assessment of androgen receptor assay results. This method incorporates both a biochemical assay and histological assessment of the assayed tissue on near-facsimile sections, an advantage over conventional biochemical assays.

Adenocarcinoma↗
PubMed1989

Pseudomembranous trigonitis of the bladder: hormonal aetiology.

Fourteen formalin fixed and paraffin wax embedded biopsy specimens from 10 women (age range 34-68) presenting with pseudomembranous trigonitis were studied using a combination of anti-oestrogen receptor monoclonal antibodies in an avidin-biotin immunoperoxidase technique. All epithelial areas showing vaginal metaplasia exhibited staining confined to the nucleus in the basal and parabasal layers of the squamous epithelium while no staining was encountered in adjacent trigonal transitional epithelium included in nine of the biopsy specimens. The selective expression of nuclear oestrogen receptor in trigonal epithelium affected by vaginal metaplasia in a distribution similar to that reported in vaginal epithelium by other workers lends further support to oestrogen mediated aetiology in this condition and is consistent with an embryological derivation of the trigone, distinct from that of the rest of the bladder.

Adult↗
PubMed1989

Assay of free and total tocainide by high performance liquid chromatography (HPLC) with ultraviolet (UV) detection.

A rapid high performance liquid chromatographic (HPLC) method for the determination of tocainide, using N-(2,6-dimethylphenyl)-2-amino-butanimide as an internal standard, was developed. A methylene chloride extraction involving salting out at pH 9.0 was employed. An 85:15 mixture of 0.025M monobasic potassium phosphate at pH 3.0 and acetonitrile was used as the mobile phase. The separation and quantitative analysis of tocainide was performed on a mixed phase column with a 1.0-mL/min flow rate and detection at 210 nm. Separation of tocainide from some of its metabolites required the use of heptane sulfonic acid as an ion-pairing reagent. For the free-drug assay, the specimen was centrifuged through an Amicon Centrifree filter before being processed.

Anti-Arrhythmia Agents↗
PubMed1988

Pain insensitivity in schizophrenic patients. A surgical dilemma.

Some schizophrenic patients have decreased pain perception while others have decreased pain expression. These factors frequently lead to difficulties in the diagnosis of acute intra-abdominal surgical emergencies. Increasingly large numbers of schizophrenic patients are being cared for in the community. It is therefore imperative that surgeons be acutely aware of the diagnostic dilemmas presented by this group of patients so that misdiagnosis is avoided and appropriate surgical therapy is instituted in a timely manner.

Abdomen, Acute↗
PubMed1988

Immunoassay of alpha 1-acid glycoprotein in the Cobas Bio centrifugal analyzer.

There is an increasing demand for quantification of serum alpha 1-acid glycoprotein (AAG, orosomucoid) in studies evaluating the protein binding of highly bound basic drugs. This paper describes an adaptation of an automated immunoturbidimetric assay for this protein to the Cobas Bio centrifugal analyzer. Replicate analyses of aliquots from six different solutions were used in determining precision. We also analyzed 367 patients' serum samples, in duplicate, to determine the distribution of AAG in hospitalized patients. The intra- and inter-run CVs ranged from 1.3% to 4.4% and from 0.6% to 6.6%, respectively. AAG concentrations in patients' samples ranged from 0.38 to 3.16 g/L. Results by this method correlate well with those by radial immunodiffusion, with no significant amount of bias between the two methods. This immunoturbidimetric procedure is faster and less expensive than currently used radial immunodiffusion techniques, and precision is acceptable.

Centrifugation↗