Breaking through the steroid stigma: a single-centre study on topical corticosteroid perception and adherence in dermatology patients and caregivers.

INTRODUCTION: Topical corticosteroid phobia is a common phenomenon that can result in poor treatment adherence and therapeutic failure. OBJECTIVES: This study aims to evaluate the prevalence and degree of topical corticosteroid phobia and its impact on treatment adherence in various dermatological conditions. Additionally, we explored the sources of information regarding topical corticosteroids. MATERIALS AND METHODS: A cross-sectional study was conducted among 300 participants with topical corticosteroid usage experience. Topical corticosteroid phobia was assessed with the topical corticosteroid phobia (TOPICOP) scale, and treatment adherence was measured with the Elaboration d'un outil d'evaluation de l'observance des traitements medicamenteux (ECOB) score. Information sources regarding topical corticosteroids were identified, and their level of trust was assessed. The data were collected via questionnaires in three languages, namely English, Malay and Mandarin. RESULTS: The study found that topical corticosteroid phobia was prevalent, with 98% of participants expressing a certain degree of phobia. The mean global TOPICOP score was 32.7 ± 6.7%. The mean score of each domain was 27.1 ± 17.2% for knowledge and belief, 35.7 ± 23.8% for fears and 40.8 ± 25.8% for behaviour. Patients/caregivers who have eczema, highly educated, severe disease, low tolerability to symptoms, previous adverse effects with topical corticosteroids and tend to traditional/non-steroidal alternative therapy usage had a significant association with topical corticosteroid phobia (p<0.05). Dermatologists were the most common and trusted source of information on topical corticosteroids. CONCLUSIONS: This study highlights the widespread topical corticosteroid phobia in dermatological practice. Dermatologists should take the lead in combating steroid phobia and provide patients with public awareness regarding topical corticosteroids to improve treatment adherence and therapeutic outcomes.

Perceptions and psychosocial judgement of patients with acne vulgaris.

INTRODUCTION: People often judge others and make decisions based on the physical appearance of an individual. This study assesses the perception and psychosocial judgment on patients with acne vulgaris compared to those with clear skin. METHODS: This survey was conducted in Penang from October 2016 to June 2017. Respondents were those who were ≥18 years. The survey was conducted using a questionnaire which consists of three randomly selected facial pictures, with at least one acne skin and one clear skin picture. RESULTS: A total of 435 respondents were recruited. Two third of the respondents (76%) suffered or had suffered from acne. The skin was the first thing noticed by 76.1% respondents when viewing pictures with acne compared with 24.8% with clear skin (p <0.05). People with acne were perceived as being unattractive, sad, lonely, distant, unhealthy, disheveled and shy as compared to people with clear skin (p<0.05). People with clear skin were perceived to be healthier, confident, happy, attractive, successful and intelligent (p<0.05). Respondents were more willing to engage socially with people with clear skin rather than those with acne skin. A significantly higher proportion of respondents were likely to hire or vote for those with clear skin as compared to acne skin. People with acne were also perceived to have a lower educational level and poorer leadership quality. CONCLUSION: The results of this survey showed that there were significantly negative perception and psychological judgement toward individuals with acne vulgaris. These negative impacts may affect social life of the acne sufferers, their prospect of employment and career opportunities.

HLA-DQ A1, -DQB1 and -DRB1 gene polymorphism--in Malay type 1 diabetes mellitus patients and their use for risk prediction.

HLA-DQA1, -DQB1, and -DRB1 gene polymorphism were analyzed to study type 1 DM susceptibility in Malay patients from Southeast Asia (Malaysia and Singapore). Patients showed significant increases in the occurrence of DQA1*0501 (50.7% vs. 20.4%; RR = 3.97; Pc < 0.01), DQB1*0201 (48% vs. 19.1%; RR = 3.86; Pc < 0.05), and DRB1*0301 (38.7 vs. 6.8%; RR = 8.36; 95% Pc < 0.05). Conversely, significant decreases were noted in the occurrence of DQA1*0601 (14.7% vs. 35.2%; RR = 0.33; Pc = 0.008) and DQB1*0601 (4% vs. 23.5%; RR = 0.16; Pc < 0.05) in type 1 DM patients. Using a logistic regression model, we derived a risk prediction model for type 1 DM in our indigenous Malay population based on the identified HLA genotypes. The RR for type 1 DM increases by a factor of 5.68 for every unit increase in the number of DRB1*0301 allele (P < 0.001), and decreases by a factor of 0.18 per unit increase in the number of DQB1*0601 allele (P < 0.001). After adjusting for these two HLA genotypes, DQA1*0501, DQB1*0201 and DQA1*0601 were not statistically significant as risk predictors. The lower incidence of type 1 DM in the Malay population may be contributed by the genotypic combinations of DR and DQ genes as well as the linkage disequilibria between susceptible and protective alleles.

Controversial endocrine interventions for the aged.

Specific endocrine changes occur with the ageing process. The last decade has witnessed significant progress in the basic and clinical science of ageing, thereby rejuvenating the interest in anti-ageing medicine, especially that of hormone replacement, by medical professionals and the lay public. However, endocrine manipulation as a therapeutic strategy for ageing is still evolving as continuing research attempts to answer the many questions of what it can achieve at the risk of incurring unknown long-term adverse effects. The current day doctor is confronted with a host of options, and will benefit from a synopsis of the latest evidence before making the most appropriate decision for aged patients seeking hormonal replacement therapy as a means to counter the effects of ageing. This review aims to give a rapid overview of the endocrine profile of geriatric population and the studies on the more controversial hormonal replacement therapies for the aged.

Intracellular localization of human DNA repair enzyme methylguanine-DNA methyltransferase by antibodies and its importance.

The human DNA repair enzyme, methylguanine-DNA methyltransferase (MGMT, M(r) 21,000), which protects cells against the mutagenic effect of alkylating carcinogens, was found to be localized in the cell nucleus (except the nucleolus) by immunofluorescence staining using polyclonal and monoclonal antibodies. The supporting experiments came from differential staining of the MGMT-deficient (mer-) and -proficient (mer+) cells, Western blotting analysis, and specific antibody depletion studies with the immobilized fusion protein, GSTMGMT-glutathione-Sepharose. Its localization in the nucleus agrees with its biological function and possibly explains the ineffective protection of mammalian cells (mer-) transfected with the Escherichia coli MGMT genes from bifunctional alkylating agents.

Accidental provocation of phaeochromocytoma: the forgotten hazard of metoclopramide?

The perilous potential of metoclopramide when used inadvertently in patients harbouring phaeochromocytomas goes largely under-recognised. Despite the rarity of phaeochromocytoma, clinicians should exercise caution in the use of metoclopramide among hypertensives and those with labile blood pressures, given the potentially life-threatening crisis it can readily evoke in those with this tumour. We report a series of three patients with phaeochromocytoma who developed acute crises from metoclopramide.

Thyrotoxic periodic paralysis complicated by near-fatal ventricular arrhythmias.

A 35-year-old Chinese man presented with acute thyrotoxic periodic paralysis complicated by near-fatal cardiac arrhythmias due to persistent hypokalaemia, despite maximum potassium supplementation. He was eventually resuscitated with external cadioversion. In this unusual case of severe refractory hypokalaemia leading to ventricular fibrillation in a patient with underlying thyrotoxicosis, the potential dangers concerning the use of dextrose infusion and beta-adrenergic agent for resuscitation are highlighted.

Fractional esterification rate of HDL particles in patients with type 2 diabetes. Relation to coronary heart disease risk factors.

OBJECTIVE: To study the fractional esterification rate of cholesterol on HDL particles (FERHDL) in adults with type 2 diabetes and assess its correlation with serum lipids and other coronary heart disease (CHD) risk factors. RESEARCH DESIGN AND METHODS: FERHDL was measured in 90 adult (57 men, 33 women) patients by an isotopic assay method involving several steps, including preparation of VLDL- and LDL-depleted plasma, labeling of the sample with a trace amount of tritiated cholesterol, separation of free and esterified cholesterol fractions by chromatography post incubation, and subsequent counting of radioactivity in the individual fractions. RESULTS: Male patients have higher FERHDL values than their female counterparts. When HDL cholesterol was controlled for in a multivariate regression analysis, the sex factor was not significant. There was a significant positive correlation between FERHDL and plasma total cholesterol (r = 0.32), triglycerides (r = 0.82), apolipoprotein B (apo B; r = 0.48), insulin (r = 0.46), BMI (r = 0.31), and waist-to-hip ratio (WHR; r = 0.50). There was a negative correlation between FERHDL and HDL cholesterol (r = -0.76) and apolipoprotein AI (r = -0.60). When both HDL cholesterol and triglycerides were controlled for, the only significant correlation was between FERHDL and BMI. CONCLUSIONS: Non-insulin-requiring type 2 diabetic patients have FERHDL, which correlated positively with triglycerides and negatively with HDL cholesterol. The positive correlation of FERHDL with serum insulin, WHR, total cholesterol, and apo B, but not that with BMI, loses its significance when HDL cholesterol and triglycerides are controlled. The sex difference between men and women in FERHDL also loses its significance when HDL cholesterol is controlled.

Pathological tumor-node-metastasis (pTNM) staging for papillary and follicular thyroid carcinomas: a retrospective analysis of 700 patients.

The TNM classification (tumor-node-metastasis) was adopted by the American Joint Committee on Cancer and the International Union against Cancer a decade ago to avoid heterogeneity of prognostic classification schemes used for differentiated thyroid cancers. To date, however, clinical data based on this classification are lacking. We retrospectively evaluate the prognosis of 700 patients (208 men and 492 women) with papillary (89%) and follicular (11%) thyroid cancers according to the pathological TNM (pTNM) staging system, treated over a 25-yr period (1970-1995). Patients who received primary treatment at our center constituted 87.4% of the cases; the majority underwent total thyroidectomy, followed by 131I ablative therapy in high risk groups, as standard treatment. Clinical and follow-up data were obtained from the medical records and our cancer registry. Disease-free and cancer-specific survival data were analyzed by Kaplan-Meier product limit estimates and Cox proportional hazard models. Patient distribution by the pTNM system were: stage I, 516 patients; stage II, 57 patients; stage III, 104 patients; and stage IV, 23 patients. Over a mean +/- SE follow-up of 11.3 +/- 0.3 yr, the overall cancer recurrence and mortality rates were 20.5% and 8.4%, respectively. However, the respective cancer recurrence and mortality rates were distinctly different in the various pTNM stages: 15.4% and 1.7% in stage I, 22% and 15.8% in stage II, 46.4% and 30% in stage III, and 66.7% and 60.9% in stage IV tumors. Using actuarial survival plots, a clear separation in both disease-free survival and cancer-specific survival was noted among all the stages (P < 0.0001). Risk factors analyses showed a significant association between all the prognostic variables used in TNM staging (age, tumor size, extent of primary tumor, and presence of nodal or distant metastases) and the observed end points of recurrence or death from thyroid cancer. After correcting for TNM stages, the risk of cancer recurrence was halved in female compared to male patients, whereas this was 1.7-fold higher in multifocal than unifocal tumors. Conversely, cancer mortality was 3.4-fold higher in follicular than papillary thyroid cancer. In the analysis of effect of primary treatment among 492 patients with tumor more advanced than the T1N0M0 category, patients who underwent less extensive surgery (lobectomy or subtotal thyroidectomy) had a 2.5-fold risk of cancer recurrence (P < 0.0001) and a 2.2-fold risk of death (P < 0.01) compared to those who underwent total or near-total thyroidectomy. Patients not treated with 131I ablation had a 2.1-fold greater risk of cancer recurrence (P < 0.0001) than those given 131I ablation, although no difference was noted in deaths from thyroid cancer. Based on our data, the pTNM classification is useful in distinguishing patients with different prognostic outcomes. However, the small patient numbers in pTNM stages other than stages I precludes us from evaluating its usefulness as a guide for therapy. Until prospective data could be accrued from controlled treatment trials, we support the standard practice of total thyroidectomy followed by 131I ablative therapy (if focal iodide uptake was noted) in patients with papillary thyroid cancer more advanced than the T1N0M0 category or of multicentric nature and in the majority of patients with follicular thyroid cancer.

Prevalence of primary aldosteronism among Asian hypertensive patients in Singapore.

Recent studies using the ratio of plasma aldosterone concentration (PAC) to PRA as the screening test for primary aldosteronism in hypertensive populations suggested that the prevalence may be as high as 5-15%, with well over half of the subjects having normal serum potassium concentrations. Despite an increasing clinical awareness of this entity, many clinicians are reluctant to consider routine screening for primary aldosteronism in essential hypertensive patients because there are few community-based prevalence studies of primary aldosteronism in different populations. Furthermore, genetic and environmental differences may affect the prevalence and presentation of primary aldosteronism in distinct populations. This study was designed to determine the prevalence of primary aldosteronism in the predominantly Chinese population in Singapore. Three hundred and fifty unselected adult hypertensive patients attending two primary care clinics had random ambulatory measurements for PAC (nanograms per dL) and PRA (nanograms per mL/h). Serum urea, creatinine, and electrolyte measurements were obtained simultaneously. Subjects with renal insufficiency (serum creatinine, >140 micromol/L) and those treated with glucocorticoids or spironolactone were excluded. Screening was considered positive if the PAC: PRA ratio was more than 20 and the PAC was more than 15 ng/dL (>416 pmol/L). Primary aldosteronism was confirmed with the determination of PAC after 2 L saline administered iv over 4 h. Adrenal computed tomographic (CT) scans were performed in biochemically confirmed cases of primary aldosteronism. Further localization with adrenal vein sampling was carried out in selected patients with equivocal findings on adrenal CT scan. Sixty-three (18%) of the 350 hypertensive patients (215 women and 135 men; age range, 23-75 yr) were screened positive for primary aldosteronism. Only 13 of these 63 subjects (21%) were hypokalemic (serum potassium, <3.5 mmol/L). Confirmatory studies were carried out in 56 (89%) of the subjects with a positive PAC:PRA ratio. Using a PAC above 10 ng/dL (>277 pmol/L) after saline infusion as the diagnostic cut-off, 16 of the 56 patients had biochemically confirmed primary aldosteronism. Hypokalemia was found in 6 of the 16 patients (37.5%) with primary aldosteronism. Subtype evaluation with adrenal CT scan and adrenal vein sampling indicated that half of the patients with primary aldosteronism may have had potentially curable unilateral adrenal adenoma. Our data suggest that primary aldosteronism occurs in at least 5% of the adult Asian hypertensive population, and approximately half of these individuals may have potentially curable, unilateral, aldosterone-producing adrenal adenoma. Our findings also confirm the poor predictive value of hypokalemia in both the diagnosis and the exclusion of primary aldosteronism.

Influence of lymphocytic thyroiditis on the prognostic outcome of patients with papillary thyroid carcinoma.

Both the association between lymphocytic thyroiditis (LT) and papillary thyroid carcinoma (PTC), and the prognostic significance of lymphocytic infiltrate in patients with thyroid malignancy, remain controversial. We examine the above relationships by retrospectively reviewing our series of patients treated for differentiated nonmedullary thyroid carcinoma at University of California-San Francisco over a 25-yr period (1970-1995). Of the 631 patients with complete data for analysis, 128 patients (20.3%) showed concomitant histologic evidence of LT and 503 patients (79.7%) had no evidence of LT. Prognostic outcome was assessed using Kaplan-Meier survival plots and analysis of risk factors by Cox's proportional-hazard modeling. The cohort with LT revealed a higher frequency of PTC (97.7% vs. 87.3%) and female patients (85.2% vs. 66.8%), a lower frequency of extrathyroidal invasion (7.8% vs. 23.3%) and nodal metastases (25.8% vs. 43.3%), and absence of distant metastases (0% vs. 4.8%), respectively, compared with those without LT. At initial surgery, a significantly greater proportion of patients with LT belonged to lower pathological tumor-node-metastasis stages, compared with those without LT (stage 1, 86.7% vs. 73%; stage 2, 4.7% vs. 8.3%; stage 3, 8.6% vs. 15.3%; and stage 4, 0% vs. 3.4%). Over a mean +/- SE follow-up period of 11.1 +/- 0.4 yr, patients with LT had significantly lower cancer recurrence rate (6.3% vs. 24.1%; P < 0.0001) and cancer mortality rate (0.8% vs. 8.0%; P = 0.001), respectively, compared with those without LT. In summary, our series showed a relatively common occurrence of LT in patients with PTC, and we believed that lymphocytic infiltration developed mainly in response to the tumor itself. We also found a more favorable course of PTC in the presence of LT; this supports the hypothesis that lymphocytic infiltration represents a form of immune reaction to control tumor growth and proliferation.

Identification of rat mammary tumor-1 gene (RMT-1), which is highly expressed in rat mammary tumors.

Full-term pregnancy early in life results in a permanent reduction in lifetime breast cancer risk in women. Parous rats and mice are also refractory to chemical carcinogenesis. Therefore, investigation of the differences between mammary glands from virgin and parous rats would provide valuable information regarding the protective effects of early full-term pregnancy. In this report, we examined the gene expression patterns in mammary glands from virgin and parous Lewis rats. Using differential display technology, a novel 4.2 kb cDNA, designated rat mammary tumor-1 (RMT-1) was isolated. Northern blot analysis of RMT-1 showed that RMT-1 expression was higher in the pre-pubertal and pubertal stages during rat mammary gland development while it was down-regulated in mammary glands from mature virgin and parous rats. RMT-1 expression was highest in rat mammary cancers compared with either the mammary glands of virgin or parous rats. At the Northern blot sensitivity level, RMT-1 expression was found only in the mammary gland. Northern blot analysis also showed that the expression of this gene was found in 74% of N-methyl-nitrosourea (MNU)-induced mammary cancers while it was not found in MNU-induced cancers from other organs. The examination of the RMT-1 gene structure revealed that it consists of five exons spanning 5.9 kb. Using fluorescence in situ hybridization, the gene was localized on rat chromosome 1 band q 43-51. The present data show that there is a correlation between high RMT-1 expression and rat mammary carcinogenesis or decreased RMT-1 expression and parity associated refractoriness to chemically induced mammary carcinogenesis. However, whether or not RMT-1 gene has a functional role in these processes remains to be investigated.

Spontaneous remission of ectopic Cushing's syndrome due to pheochromocytoma: a case report.

A young female adult with Cushing's syndrome arising from ectopic production of corticotropin (ACTH) from an adrenal pheochromocytoma showed spontaneous clinical and biochemical remission of hypercortisolism after a brief period of ketoconazole administration. Despite continued remission of the hypercortisolism over the next 18 months, there was progressive catecholamine hypersecretion with significant morbidity as a result of the pheochromocytoma. Surgical resection of the left adrenal gland revealed a pheochromocytoma showing focal cytoplasmic immunostaining for ACTH and marked diffuse compact cell hyperplasia in the adrenocortical tissue. To our knowledge this is the first reported case of spontaneous clinical and biochemical remission of ectopic ACTH production from a pheochromocytoma. The pathogenesis of the remission remains unknown.

Diabetes insipidus from sarcoidosis confined to the posterior pituitary.

A young white man with new-onset central diabetes insipidus was discovered to have a posterior pituitary mass on magnetic resonance imaging. No other radiological abnormalities were noted in the anterior pituitary, infundibulum or hypothalamus. No other endocrinopathies were present: laboratory investigations showed normal basal concentrations of anterior pituitary hormones, including prolactin. The patient was suspected to have sarcoidosis affecting the posterior pituitary, because of the discovery of pulmonary sarcoidosis during his diagnostic evaluation. His symptoms of polydipsia and polyuria responded promptly to intranasal administration of 1-desamino-8-D-arginine vasopressin (DDAVP). The patient demonstrated complete regression of the posterior pituitary mass after a course of corticosteroid therapy. However, his diabetes insipidus persisted and he continues to need DDAVP treatment, currently at 12 months of follow-up. The resolution of the neurohypophysial mass was compatible with the diagnosis of pituitary sarcoidosis and this precluded the need for a transsphenoidal biopsy or surgery.

Phaeochromocytoma: a ten-year survey.

We retrospectively evaluated our experience with phaeochromocytoma from January 1986 to December 1995. There were 18 patients with surgically-proven phaeochromocytoma: three males, 15 females, aged 12-81 years (mean 42 years) at diagnosis. Sixteen were hypertensive; only 6/18 presented with two or more of the classical triad of headaches, palpitations and diaphoresis. One patient presented with hypertensive crisis. Duration of symptoms prior to diagnosis was 2 weeks to 6 years, mean 16.4 months. Sixteen patients had adrenal tumours and two had extra-adrenal tumours or paragangliomas. One had bilateral adrenal tumours and two had a combination of both adrenal and extra-adrenal tumours. There were four familial cases: two had multiple endocrine neoplasia type IIA (MEN-IIA), one had neurofibromatosis type I (NF-I) and one von Hippel-Lindau (VHL) disease. One patient had Cushing's syndrome arising from ectopic production of adrenocorticotropic hormone (ACTH) by the phaeochromocytoma. Disease was recurrent in three patients. Pre-operative diagnosis was confirmed mainly by elevated urine vanillylmandelic acid (VMA) and/or catecholamine levels. Twelve patients had plasma catecholamine determinations: noradrenaline was elevated in all, adrenaline in six and dopamine in two. Pre-operative localization was by CT scan or MR imaging in all patients. At follow-up of 1-10 years (median 4.8 years), 15 patients were cured surgically while two were asymptomatic despite recurrence of disease. One patient with recurrent paragangliomas died post-operatively.

A serotype-specific epitope of dengue virus 1 identified by phage displayed random peptide library.

From a panel of monoclonal antibodies of dengue viruses, a serotype-specific epitope of dengue virus 1 was screened from a random peptide library displayed on phage. The epitope was the determinant reactive with monoclonal antibody 15F3-1 that was specific to dengue 1. The screening was monitored by a dot blotting procedure, and after three rounds of screening a consensus motif, HRYSWK, was found. This sequence matches the sequence HKYSWK, corresponding to the amino acid residues 885-890 of polyprotein or residues 111-116 of the non-structural protein 1 of dengue virus serotype 1. The linear epitope was confirmed by testing the antigenicity of chemically synthesized 8-branched peptide.

Death from thyroid cancer of follicular cell origin.

BACKGROUND: Although patients with differentiated thyroid cancer (DTC) of follicular cell origin usually have an excellent prognosis, some patients die from progressive tumor. Numerous postoperative criteria have been used to predict prognosis in patients with DTC. The purpose of this investigation was to determine whether the TNM and metastases, age, completeness of resection, invasion, size (MACIS) classifications predicted survival time and why patients died from DTC. The extent of initial treatment and causes of death were also evaluated in these patients who died from thyroid cancer. STUDY DESIGN: Between 1965 and 1995, 102 of 1,224 patients with DTC treated at the University of California at San Francisco (UCSF) and UCSF/Mount Zion Medical Centers died from DTC. Risk factors including age at diagnosis, gender, histologic characteristics, TNM and MACIS classifications, the intervals among initial treatment, recurrence, and death, and the initial and subsequent treatments were documented in these 102 patients. RESULTS: Among the 102 patients who died of DTC 50% were men and 50% were women. The mean age of patients with DTC at diagnosis was 58 years at recurrence, 62 and 65 years at death. Thirty percent of these patients initially had unilateral thyroid operations and 70% had a bilateral operation. Tumors at presentation ranged from 0.6 to 13.0 cm (mean 4.4 cm); 46% of patients presented with late-stage tumors (TNM stage III, IV; MACIS score > 8). At presentation 46% of the patients had locally recurrent disease or regional metastases and 18% had distant metastases. Patients with persistent disease had a significantly shorter survival time than those with recurrent disease (p < 0.001). Both TNM and MACIS classifications were good predictors of survival time. Reoperations were performed in 51% of papillary, 26% of follicular, and 67% of Hürthle cell thyroid cancer patients. Fifty percent of patients with papillary thyroid cancer, 50% of patients with Hürthle cell thyroid cancer, and 11% of patients with follicular cell thyroid cancer died of locally advanced disease. CONCLUSIONS: As expected, patients with local or regional recurrence and those with TNM stage I or MACIS score < 6 survived longer than patients with distant metastasis and TNM stage III or IV, MACIS score > 6, but some patients thought to be at low risk (TNM stage I; MACIS < 6) also died from thyroid cancer.

Familial nonmedullary thyroid carcinoma: a meta-review of case series.

Familial occurrence of nonmedullary thyroid carcinoma is extremely rare but this has been increasingly recognized over the recent years. Earlier reports of such occurrence were primarily confined to individuals with previous radiation exposure, history of familial adenomatous polyposis (Gardner's syndrome) or multiple hamartomas (Cowden's syndrome), or monozygotic twins. The author reviews 15 case reports/series of familial nonmedullary thyroid carcinoma available in the literature involving kindreds with no obvious associated pathogenetic factors as mentioned above. There were a total of 87 kindreds with 178 affected individuals available for analysis, with a male to female ratio of 1:2.2. The modal age group at diagnosis was 30-39 years in both gender groups. Papillary thyroid carcinoma constituted 91% of the cases, followed by follicular (6%) and anaplastic (2%) varieties. There was one case (0.5%) each of combined papillary and medullary thyroid carcinoma and Hurthle cell carcinoma, respectively. Six of the 15 series observed that patients with familial history generally have more aggressive tumour characteristics compared to the sporadic counterparts. The incidences of multifocality, local invasion, and distant metastases at diagnosis were 49, 32, and 5%, respectively. The incidences of locoregional recurrence, distant metastases, and deaths were 29, 10, and 5.4%, respectively, at a mean follow-up period of 11 years. The actual prognostic outcome of familial nonmedullary thyroid carcinoma is still unclear in view of the limited clinical data. Although several authors have advocated an aggressive approach in managing these patients, no conclusion can be reached on the basis of this review to support this position. The author recommends that patients with familial disease should be treated according to the disease stage and other risk factors, similar to those with spontaneously occurring well-differentiated papillary or follicular thyroid carcinomas. In addition, one might consider and perform follow-up of first-degree relatives with similar degree of caution as patients who have undergone head and neck irradiation in childhood.

Contribution of axial dispersion to band spreading in perfusion chromatography.

A new interpretation of the band spreading data in perfusion chromatography is proposed by investigating the relative importance of axial dispersion in perfusive beds. Elution chromatography of proteins (bovine serum albumin and lysozyme) under non-retained conditions on two kinds of reversed-phase perfusive supports (POROS R1/H and POROS R2/H), which have different pore structures, were carried out to obtain the axial dispersion data. The Knox equation and some empirical correlations for dispersion coefficients in porous media were applied to correlate the experimental data. The influences of particle properties, solute molecular sizes and flow velocity on the dispersion coefficient were elucidated. Axial dispersion was recognised to be the main contributor to peak broadening in perfusion chromatography. The dependence of the height equivalent to a theoretical plate on flow-rate was found to be the result of the velocity dependence of the axial dispersion. The dispersion coefficient in a perfusive column can be well represented both by a power-law relationship and a correlation derived based on stochastic theory. Pursuant to these, it was found that pore size distribution of the perfusive particles and solute molecular size are important parameters, which influenced the dispersion results significantly.

Role of polyethyleneimine in the purification of recombinant human tumour necrosis factor beta.

The chromatographic behaviour of recombinant human tumour necrosis factor beta (rhTNF-beta) (pI approximately 9.0) during cation-exchange chromatography at pH 7.5 is investigated. Without prior treatment of the Escherichia coli cell extract with polyethyleneimine (PEI), very little rhTNF-beta was bound to the column. However, upon addition of 5% PEI (100 microliters ml-1) to the cell lysate, rhTNF-beta was shown to bind to cation-exchange columns normally. TNF-beta was readily precipitated from the clarified cell extract by 20% ammonium sulphate, but ony ca. 25% of this precipitate could be re-solubilized for further purification. However, when 5% PEI was included in the solubilization buffer, the balance of the rhTNF-beta could be recovered. It is proposed that charge interaction between rhTNF-beta and nucleic acids in the cell extract is responsible for both of these anomalous phenomena, and that PEI (a cationic polyelectrolyte) was able to disrupt this interaction by displacing rhTNF-beta from the charge complex.