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Biomedical subjects

B Jemec

Publications and source records attributed to B Jemec.

At least 19 recordsLinked to original sources

A prospective randomised clinical trial of the intra-operative use of 5-fluorouracil on the outcome of dupuytren's disease.

5-Fluorouracil reduces proliferation rates of fibroblasts, myofibroblast differentiation and contractility of ocular fibroblasts in vitro. This double-blind randomized clinical trial assesses whether intra-operative topical treatment with 5-fluorouracil reduces the recurrence rate after limited excision of Dupuytren's tissue. Patients with two-digit disease were randomized to having 5-fluorouracil (25mg/ml) treatment for 5 minutes on one digit and placebo on the other. Fifteen patients were enrolled with 18 months follow-up. There were no peri-operative complications. Wound healing was not delayed and there was no deterioration in the flexion deformity of the 5-fluorouracil treated digits. Patients were subsequently assessed by joint angle measurement at 3, 6, 12 and 18 months. There was no significant difference between control and 5-fluorouracil treated digits.

Antimetabolites↗

The effect of 5-fluorouracil on Dupuytren fibroblast proliferation and differentiation.

INTRODUCTION: Dupuytren's disease is a proliferative disease with contractile properties, prone to recur after surgery. Intra-operatively applied 5-fluorouracil has been used to avoid scar problems in the eye after glaucoma filtration surgery and was therefore investigated as a means to inhibit proliferation and myofibroblast differentiation in Dupuytren fibroblasts in vitro. METHOD: Primary cell lines were obtained by explants from Dupuytren's tissue (n = 6), non-diseased palmar fascia from patients with Dupuytren's disease (n = 3) and carpal ligament from patients undergoing carpal tunnel release (n = 3). The effect of 5-fluorouracil on proliferation was assessed by cell counting. Myofibroblast differentiation, an intergral part of Dupuytren's contracture, was investigated by staining for alpha smooth muscle actin, a marker for contractile cells, using immunohisto-chemical methods. RESULTS: A single exposure to 5-fluorouracil caused a sustained inhibition of proliferation in Dupuytren's and non-diseased fascia cultures, whilst the effect on carpal ligament cultures was transient. Untreated Dupuytren's fibroblasts exhibited the highest myofibroblast differentiation, whilst differentiation in non-diseased fascia cultures was shown to be proportional to cell density and virtually non-existent in carpal ligament cultures. After 5-fluorouracil exposure, the differentiation was significantly reduced in Dupuytren's fibroblasts cultures, reduced at high cell densities in non-diseased fascia and unchanged in carpal ligament cell cultures. DISCUSSION: 5-fluorouracil inhibits both proliferation and myofibroblast differentiation in Dupuytren's cell cultures and may have a potential use as an adjuvant treatment to Dupuytren surgery in order to reduce the rate of recurrence and contracture.

Aged↗

The Merkel cell carcinoma: survival and oncogene markers.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare and malignant tumour. Survival data and prognostic factors are scarce. AIM: To investigate the usefulness of biological markers to predict the prognosis for these aggressive tumours. METHODS: C-myc oncoprotein and proliferation was analysed in specimens from 13 patients with MCC, treated between 1983 and 1997. The average age at presentation was 68.3 years. Overall follow-up ranged from 14 to 158 months, with a mean of 68.2 months. Specimens were analysed by immunohistochemistry for proliferation (mib-1) and flow cytometry for oncogene activity (c-myc). RESULTS: The median positivity was 52% for the c-myc oncogene and 50% for proliferation, but these did not correlate to survival as analysed by the Kaplan-Meier method. Other parameters such as median age at presentation, sex, site of tumour and adjuvant radiotherapy were also analysed, but none were found to be significant. CONCLUSIONS: This study showed that neither c-myc oncogene activity or mitotic index in MCC can be related to patient survival.

Aged↗

The abnormal nucleus as a cause of congenital facial palsy.

BACKGROUND: Congenital facial palsy (CFP) is clinically defined as facial palsy present at birth. It is associated with considerable disfigurement and causes functional and emotional problems for the affected child. The aetiology of the majority of cases however, remains elusive. AIMS: To investigate the role of a neuroanatomical abnormality as a cause of unilateral CFP. METHODS: Magnetic resonance imaging (MRI) scans were performed on 21 patients with unilateral CFP. Fifteen patients had unilateral CFP only; six suffered from syndromes which can include unilateral CFP. RESULTS: Of the 15 patients with unilateral CFP only, four (27%) had an abnormal nucleus or an abnormal weighting of this area on the MRI scan, compared to one (17%) of the remaining six patients. CONCLUSION: Developmental abnormalities of the facial nucleus itself constitute an important, and previously ignored, cause of monosymptomatic unilateral CFP.

Adolescent↗

A functional variant of lower lip reconstruction.

A functional variant of lower lip reconstruction is reported, in which a nasolabial skin flap was combined with upward transposition of the inferior part of the orbicularis oris muscle in a 'bucket-handle' fashion. The tongue was split to provide both an intraoral lining to the lip and a new vermilion.

Animals↗

Is Dupuytren's disease caused by an imbalance between proliferation and cell death?

Dupuytren's contracture shares certain properties with malignant tumours, characterized by proliferation and lack of apoptosis, which may be induced by the c-myc oncogene. Because of these similarities, the relationship between the c-myc oncogene expression, bcl-2 oncogene (anti-apoptotic gene) and proliferation was investigated in Dupuytren's disease. Proliferation was assessed by immunohistochemical staining of the mib-1 antibody. Results were compared with those from fibrosarcoma specimens, representing a related malignant tumour. Non-diseased fascia from Dupuytren patients and flexor retinaculum from patients undergoing carpal tunnel release without Dupuytren's disease were used as controls. Expression of c-myc was elevated in primary Dupuytren's disease and fibrosarcoma specimens, whilst recurrent Dupuytren's disease, non-diseased Dupuytren fascia and flexor retinaculum exhibited significantly lower levels. Neither bcl-2 nor mib-1 were detected in Dupuytren's disease, non-diseased fascia or flexor retinaculum, in contrast to fibrosarcoma. The imbalance between proliferation and apoptosis, producing malignant growth was thus confirmed for fibrosarcoma, but not for Dupuytren's disease.

Adult↗

Giant solitary trichoepithelioma.

The giant solitary trichoepithelioma is a rare trichogenic tumor with potential for local recurrence. Only nine cases have been previously described in the literature, and one additional case without recurrence during the first 3.5 years of observation is presented stressing that the rate of recurrence is low.

Hair Follicle↗

The effect of superficial hydration on the mechanical properties of human skin in vivo: implications for plastic surgery.

The influence of topically applied tap water on the mechanical properties of human skin was studied in vivo by applying tap water to the ventral aspect of the forearms of 18 healthy volunteers for 10 or 20 minutes and then measuring distensibility, elastic retraction, and hysteresis. Significant increases in distensibility, resilient distensibility, and hysteresis were noted after 20 minutes of soaking. Most of these findings were already apparent after 10 minutes. This study shows that the epidermis plays a significant role in determining the mechanical properties of human skin. Possible practical implications of superficial skin hydration for plastic surgery such as tissue expansion and larger excisions are briefly discussed.

Adult↗

Studies of the goitrogenic and tumorigenic effect of two goitrogens in combination with hypophysectomy or thyroid hormone treatment.

The influence of hypophysectomy, triiodothyronine (T3), and thyroxine (T4) on the goitrogenic and tumorigenic activity of methylthiouracil (MTU) and 1-methyl-2-mercapto imidazol (MMI) was studied in rats. Hypophysectomy effectively prevented the development of thyroid hyperplasia and adenomas in MTU-treated animals. T3 reduced or abolished the weight loss of goitrogen-treated animals, and prevented the development of thyroid hyperplasia, adenomas, and pulmonary metastatic nodules. The effect of T4 was less pronounced, especially in MTU-treated animals. This hormone failed to neutralize the goitrogenic effect of MTU but it did reduce significantly the incidence of thyroid adenomas and prevented the appearance of pulmonary lesions. The biological effect of the thyroid hormones correlated with their effect on the serum levels of TSH, T3, and T4. The observations are compatible with the assumption that the tumorigenic effect of the two goitrogens depends upon a state of imbalance between TSH and T3.

Adenoma↗

Studies of the tumorigenic effect of two goitrogens.

The nature of tumors appearing in the thyroid gland and in the lungs of mice fed two standard goitrogenic drugs (MTU and MII) has been studied. These tumors have been considered malignant on the basis of their morphological appearance and their occurrence in abnormal locations. Some investigatiors, however, have questioned that they are actually malignant. The present results indicate that these tumors are most likely not malignant even if it is shown that the pulmonary nodules are of thyroid origin. The thyroid adenomas disappear once the goitrogen is withdrawn, but thryoid enlargement pesists, and event 6 months after discontinuation of the goitrogenic treatment , pulmonary nodules are still produced. Evidence is presented that these nodules are emoli from hyperplastic thyroid tissue and not tumors.

Adenoma↗

Prediction of local recurrence in colorectal carcinoma: an LDH isoenzymatic assay.

In a previous study of colorectal carcinoma, the LDH isoenzyme pattern was determined in 420 tissue biopsies from 36 surgical specimens. The LDHIV/LDHII ratio was increased in tumour tissue, but in a number of cases increased ratios were found in the morphologically uninvolved tissue as well. This was especially pronounced in cases with multiple tumours. The isoenzymatic changes were interpreted therefore as a possible indicator of an early process of malignant conversion. In order to test this hypothesis the original material has been reviewed after observation periods ranging from 5 to 7 years. It appears that the mean LDHVI/LDHII isoenzyme ratio of resection edge biopsies is high (0-92) in patients succumbing with local recurrence, differing significantly (P less than 0-01) from the corresponding mean ratio (0-66) in patients clinically cured.

Adult↗

Abrasio axillae in hyperhidrosis.

Forty-one patients with hyperhidrosis axillae were operated on. The subcutaneous curettage in 20 patients was compared with radical excision in 21 patients. Comparison of the results of both operations disclosed no difference in the elimination of the sweat secretion, but the method of curretage is superior, because it can be repeated if necessary and leaves practically no scars.

Axilla↗

Surgical treatment of paronychia granulomatosa hallucis.

Paronychia granulomatosa is a complication incident to unguis incarnatus; surgery for this complaint was performed on 26 patients with 52 granulomas. The operation was first described by Bartlett in 1937. The postoperative hospitalization was 3 days and the patients returned a week later to have the sutures removed. After the operation, ten remaining granulomas were observed of which 6 were cured by operation and 2 conservatively, leaving 2 under continuing conservative treatment (5 months and 1 month, respectively).

Adolescent↗