Immunohistochemical metallothionein expression in thymoma: correlation with histological types and cellular origin

Metallothioneins (MTs) are low molecular weight and cysteine-rich intracellular proteins involved in metal homeostasis and detoxication. They are found in certain normal tissues, and are overexpressed in various tumours with correlation to more aggressive behaviour in certain tumours. Since the histopathological types of thymoma have unpredictable invasive potential, MT over-expression was investigated as a possible marker of the invasive potential of thymomas. We studied immunohistochemical MT expression in 27 non-invasive thymomas, 20 micro-invasive thymomas, and 23 macro-invasive thymomas with a mouse monoclonal anti-MT antibody E9 on formalin-fixed paraffin-embedded tissues. MT expression was significantly different among the three groups of thymomas ( P  = 0.02) with a stronger expression in invasive thymomas ( P  = 0.003). However, MT expression was not exclusively limited to invasive thymomas. Therefore, it could not be used as a marker of aggressive potential in individual thymomas. Analysis of MT expression according to the histological types of the thymomas revealed that eight of nine spindle cell thymomas, none of 10 small polygonal cell thymomas, four of 14 mixed thymomas, seven of 29 large polygonal cell thymomas, and seven of eight squamoid thymomas significantly expressed MT. There was a statistically significant difference in MT expression among different histological types of thymomas ( P  = 0.000). The strongest and most consistent expression was observed in spindle cell thymoma and squamoid thymoma. Since spindle cell thymoma was usually non-invasive and squamoid thymoma was more aggressive, MT expression does not correlate with the invasive potential of different histological types of thymomas. But because medullary epithelial cells of the thymus were positive for MT, our results suggest that both spindle cell thymoma and squamoid thymoma might derive from the medullary compartment of the thymus.     

PHOTODAMAGE AND SKIN CANCER AMONG PARAQUAT WORKERS

Background. Some workers in paraquat manufacturing, exposed to bipyridines, have developed pigmentation and keratosis on sun-exposed skin. This condition has been described as skin-malignancy or premalignancy. This study was designed to clarify the pathologic features of these lesions and to explore the etiologic role played by bipyridine. Methods. Twenty-three biopsy specimens, obtained from the affected skin of 10 workers, were scrutinized by a dermatopathologist. A total of 242 exposed workers from 28 paraquat factories were examined and interviewed during the period from 1983 to 1991. The severity of the characteristic skin lesions was graded from the lowest to the highest response to analyze the data by Mantel extension for a trend that focused on the heavy exposure to bipyridines as risk factor. Results. All pathology specimens showed various degrees of solar damage: early actinic change, solar lentigo, actinic keratosis (AK), AK coexisting with squamous cell carcinoma (sec), and sec. Six specimens from four workers were sec or sec in situ. Three of six sec showed the coexistence of AK. Of the workers, 133 had skin lesions ranging in severity from grade 1 to grade 3 on sun-exposed areas. The severity of skin changes is strongly associated with heavy exposure to bipyridines (P < 0.0001). Conclusion. This pathologic study proves that all the lesions showed either photodamage or skin cancer. The strong trend in the correlation between severity of photo-damage and exposure to bipyridine leads to the speculation about the synergistic role of bipyridine exposure and the solar effect in causing these malignant and premalignant skin lesions.     

Urinary Nerve Growth Factor Levels in Urinary Tract Diseases With or Without Frequency Urgency Symptoms

Objectives: To measure urinary nerve growth factor (NGF) levels in patients with several urinary tract diseases under different conditions and compare with NGF levels in patients with overactive bladder (OAB) and interstitial cystitis/painful bladder syndrome (IC/PBS). Methods: Urinary NGF levels were measured using enzyme‐linked immunosorbent assay (ELISA) and normalized by urinary creatinine concentration. Patients with acute bacterial cystitis, urinary tract stone, urothelial cell carcinoma, and OAB patients after antimuscarinic therapy were evaluated. The urinary NGF levels of OAB, IC/PBS and controls from previous studies were used for comparison. NGF levels were compared among subgroups and between urinary tract diseases with or without associated OAB symptoms. The urinary NGF levels were also compared among natural filling, after normal saline filling and after potassium chloride test in a group of OAB and IC/PBS patients. Results: Patients with acute bacterial cystitis, urinary tract stones or urothelial cell carcinoma had elevated NGF levels that were not associated with the presence of OAB symptoms. Symptomatic cystitis patients who had resolved OAB symptoms after antibiotic treatment had a significant decrease in urinary NGF levels. The urinary NGF levels decreased significantly in OAB patients with effective antimuscarinic treatment for 6 months, but remained stationary and higher than the controls for up to 12 months after treatment. Conclusion: Urinary NGF is not produced solely in patients with OAB or IC/PBS. Acute bacterial cystitis, urinary tract stones and urothelial cell carcinoma can have high urinary NGF production.     

肺特灵Ⅵ号对博莱霉素诱导的小鼠肺纤维化的干预作用及其机制

目的观察肺特灵Ⅵ号对博莱霉素诱导的小鼠肺纤维化的干预作用。方法采用气管内注入博莱霉素法制备小鼠肺纤维化模型。给药28d后处死,计算肺系数;观察肺脏病理形态学改变,并对肺泡炎和肺纤维化程度进行评分;测定小鼠肺组织中超氧化物歧化酶（SOD）、丙二醛（MDA）、总抗氧化能力（T-AOC）与羟脯氨酸（HYP）等生化指标。结果与模型组相比,肺特灵Ⅵ号各剂量组可明显增加小鼠体质量,降低肺系数,减轻肺泡炎与肺纤维化程度,提高肺组织SOD活性与T-AOC,降低MDA与HYP含量（P〈0.05或〈0.01）。结论肺特灵Ⅵ号对博莱霉素诱导的小鼠肺纤维化有一定的防治作用。     

Mechanisms of Transition Between Double Paroxysmal Supraventricular Tachycardias

INTRODUCTION: Coexistence of double tachycardias in one patient has been infrequently reported. Furthermore, the mechanisms of transition between double paroxysmal supraventricular tachycardias have not been well studied. METHODS AND RESULTS: Thirty-five patients with two paroxysmal supraventricular tachycardias were studied. Group IA consisted of 3 patients with spontaneous transition between AV reciprocating tachycardia (AVRT) and AV nodal reentrant tachycardia (AVNRT). Group IB consisted of 13 patients without spontaneous transition between AVRT and AVNRT. Group IIA consisted of 5 patients with spontaneous transition between AVNRT and atrial tachycardia (AT). Group IIB consisted of 14 patients without spontaneous transition between AVNRT and AT. The absolute values of differences between the two tachycardia cycle lengths were significantly smaller in patients with than in those without transition between the two tachycardias (25+/-8 msec vs 90+/-46 msec, P < 0.05, IA vs IB; 21+/-25 msec vs 99+/-57 msec, P < 0.01, IIA vs IIB). The cutoff point of 25 msec had 80% positive predictive value for transition between the two tachycardias. Transition between two tachycardias occurred due to a spontaneous premature atrial complex (30%), conduction block at one limb of tachycardia (20%), or tachycardia-induced tachycardia (50%). Absence of transition between two tachycardias might be explained by the absence of a spontaneous premature atrial complex, longer cycle length of the first tachycardia, larger difference between two tachycardia cycle lengths, or induction of each tachycardia under different situations. CONCLUSION: Double supraventricular tachycardias with similar tachycardia cycle lengths are vulnerable to transition between different tachycardias.