Metal contamination in benthic macroinvertebrates in a sub-basin in the southeast of Brazil.

Benthic macroinvertebrates have many useful properties that make possible the use of these organisms as sentinel in biomonitoring programmes in freshwater. Combined with the characteristics of the water and sediment, benthic macroinvertebrates are potential indicators of environmental quality. Thus, the spatial occurrence of potentially toxic metals (Al, Zn, Cr, Co, Cu, Fe, Mn and Ni) in the water, sediment and benthic macroinvertebrates samples were investigated in a sub-basin in the southeast of Brazil in the city of São Carlos, São Paulo state, with the aim of verifying the metals and environment interaction with benthic communities regarding bioaccumulation. Hypothetically, there can be contamination by metals in the aquatic environment in the city due to lack of industrial effluent treatment. All samples were analysed by the USEPA adapted method and processed in an atomic absorption spectrophotometer. The sub-basin studied is contaminated by toxic metals in superficial water, sediment and benthic macroinvertebrates. The Bioaccumulation Factor showed a tendency for metal bioaccumulation by the benthic organisms for almost all the metal species. The results show a potential human and ecosystem health risk, contributing to metal contamination studies in aquatic environments in urban areas.

Cold fronts and reservoir limnology: an integrated approach towards the ecological dynamics of freshwater ecosystems.

In this paper the authors discuss the effects of cold fronts on the dynamics of freshwater ecosystems of southeast South America. Cold fronts originating from the Antarctic show a monthly frequency that promotes turbulence and vertical mixing in reservoirs with a consequence to homogenize nutrient distribution, dissolved oxygen and temperature. Weak thermoclines and the athelomixis process immediately before, during and after the passage of cold fronts interfere with phytoplankton succession in reservoirs. Cyanobacteria blooms in eutrophic reservoirs are frequently connected with periods of stratification and stability of the water column. Cold fronts in the Amazon and Pantanal lakes may produce fish killings during the process of "friagem" associated mixing events. Further studies will try to implement a model to predict the impact of cold fronts and prepare management procedures in order to cope with cyanobacteria blooms during warm and stable water column periods. Changes in water quality of reservoirs are expected during circulation periods caused by cold fronts.

[Idiopathic esophageal rupture (Boerhaave syndrome)].

The idiopathic esophageal rupture, Boerhaave syndrome, is very rare disease. Early diagnosis and treatment will produce good clinical course. We experienced a case of Boerhaave syndrome with good clinical prognosis because of the prompt diagnosis and surgical repair by thoracotomy. A 58-year-old man complained sudden chest pain after vomiting. Esophageal rupture was diagnosed by chest computed tomography, and the operation was performed after 5 hours from the onset. The lesion of the esophageal rupture was on the left side of esophagus just above the diaphragm 3 cm in length, which was detected by the combination of thoracoscopy and upper gastrointestinal endoscopy. The postoperative clinical course was uneventful and he discharged from our hospital 17 days after the thoracotomy. Further development of imaging techniques and surgery, such as intraoperative endoscopy and thoracoscopy, are useful for the treatment and diagnosis of Boerhaave syndrome.

[Thymic basaloid carcinoma].

We report a case of thymic basaloid carcinoma combined with multilocular thymic cyst (MTC). A 72-year-old man was found to have an abnormal shadow on a chest X-ray without pny symptoms. Chest computed tomography (CT) showed a smooth edged anterior mediastinum tumor projecting to the left lung field. After preoperative chemotherapy by irinotecan hydrochloride (CPT-11) and radiotherapy of 40 Gy, chest CT showed a large part of the tumor projecting to the left lung field had changed to a cyst. After the pericardium and upper lobe of the left lung to which the MTC adhered was partially resected via left thoracotomy, the tumor was resected with innominate vein via median sternotomy. The operation was followed by CPT-11 chemotherapy and radiotherapy of 20 Gy. The tumor was thymic basaloid carcinoma 3 x 2.5 x 2 cm in size combined with MTC 8.2 cm maximum in diameter. As he died of another disease 6 months after excision, sufficient postoperative observation was not obtained. Thymic basaloid carcinoma is rare and only 14 cases including the present case have been reported.

[Successful treatment of bronchial mucoepidermoid carcinoma by bronchoplasty].

A 63-year-old man who was pointed out abnormal shadow on chest X-ray admitted to our hospital. Chest computed tomography (CT) showed a tumor originated from right upper bronchus and grew into right main bronchus. The tumor was diagnosed as mucoepidermoid carcinoma by bronchoscopic biopsy. Fluorodeoxyglucose positron emission tomography (FDG-PET) showed abnormal uptake localized at the tumor. The standardized uptake values of the tumor 60 minutes after injection were 2.86, and 120 minutes after injection, it increased to 3.97. Right upper lobectomy with bronchoplasty by deep wedge resection of right main bronchus at the orifice of right upper bronchus and lymphadenectomy was performed. Pathological diagnosis was high-grade mucoepidermoid carcinoma without lymph nodes metastasis which was compatible with FDG-PET. Postoperative course was uneventful.

[A pulmonary tumorlet with caseous granuloma associated with atypical mycobacterium].

We encountered a case of pulmonary tumorlet with caseous granuloma associated with atypical mycobacterium. A 73-year-old woman was admitted to the hospital because a chest x-ray film showed enlargement of an abnormal shadow in the middle lobe of the right lung. Primary lung cancer was suspected and right middle lobectomy was performed. Acid-fast bacilli (Gaffky 1) were found in a caseous lesion and examination of intraoperatively obtained frozen specimens showed caseous granulomas. The bacilli were later identified as Mycobacterium avium complex. The permanent specimen showed a minute lesion consisting of small clusters of epithelial cells resembling carcinoid tumor in contact with granulomatous tissue. Histopathological examination revealed argyrophilia on Grimelius stain and immunoreactivity to chromogranin-A in the clusters of epithelial cells. Although these results are consistent with small cell carcinoma or peripheral carcinoid tumor, pulmonary tumorlet was diagnosed because of the lesion's small and minimal cytologic atypia, and because of chronic pulmonary damage around the lesion. Pulmonary tumorlets are minute, usually microscopic, tumor-like lesions mostly found in damaged lung tissue obtained at autopsy or during surgery. Morphological diagnosis is sometimes very difficult, but recently these lesions have been regarded as hyperplastic lesions arising in pulmonary neuroendocrine cells (Kultschitzky cells) and caused by chronic pulmonary damage, such as hypoxia and inflammation. Pulmonary tumorlets must be considered in the differential diagnosis of minute lesions suspected to be small cell carcinoma or peripheral carcinoid tumor.

Fluorescence-based polymerase chain reaction-single-strand conformation polymorphism analysis of p53 gene by capillary electrophoresis.

Mutation of the p53 gene plays an important role in neoplastic progression in human tumorigenesis. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) techniques are now available for the detection of point mutations. The original method using polyacrylamide gel electrophoresis is disadvantageous, particularly for clinical tests and for analysis of large numbers of samples. Therefore, using an automated capillary electrophoresis (CE) technique with a molecular-sieving polymer solution, we have devised a completely automatic fluorescence-based PCR-SSCP system (CE-FSSCP) for the differential detection of point mutations that dose not require SSCP with radioisotopes and polyacrylamide gels. The automatic CE-FSSCP system was developed for reproducible operations in the denaturation of double-stranded DNA and electrophoresis of single-stranded DNA. The detection system consists of a 100 W I2 lamp and photomultiplier. We performed CE-FSSCP with a 2% linear polyacrylamide polymer solution containing 5% glycerol. Four tissue specimens of lung tumors with mutations in exon 7 of the p53 gene were found to have mutant alleles; six-base-pair deletion at codons 247-248, a one-base-pair deletion at codon 260, a one-base-pair deletion at codon 244 and a GGC to CGC substitution at codon 244. We expect this technique to prove useful for the clinical DNA diagnosis of human cancers, determination of the therapeutic effect of anticancer agents and for the study of the molecular aspects of the mechanisms involved in the pathogenesis of human cancers.

[Flow cytometric analysis of the DNA content of resected non-small cell lung cancer with reference to long-term follow-up].

We measured the cellular DNA content of paraffin-embedded tumor specimens by flow cytometry from 340 cases of resected non-small cell lung cancer, and investigated the correlation of DNA content and prognosis of these cases with long-term follow-up. These 340 cases were divided into some populations according to pathological stage, histologic type, surgical curativity and N factor, and we compared the prognosis of DNA diploidy cases and DNA aneuploidy cases in each population. DNA aneuploidy cases had a significantly less favorable prognosis than DNA diploidy cases in population of stage I adenocarcinoma, stage IIIA non-small cell lung cancer and N2 cases among stage IIIA non-small cell lung cancer, all after curative operation. But in other populations, there was no significant difference in prognosis between DNA diploidy cases and DNA aneuploidy cases. In conclusion, DNA ploidy pattern is a prognostic factor for survival in patients with stage I adenocarcinoma and N2 cases of stage IIIA non-small cell lung cancer.

[T cell lymphoma presenting as recurrent bilateral pulmonary infiltrates over five years].

A 52-year-old man presented with BOOP-like recurrent bilateral pulmonary infiltrates. In 1989 a chest X-ray film showed an infiltrative shadow in the right S6 region which disappeared after administration of prednisolone. Thereafter, bilateral patchy infiltrates recurred many times, and each time they resolved rapidly with steroid therapy. Skin eruptions on the face recurred. In October 1994 the patient underwent an open-lung biopsy of the infiltrate in the left S6 region. The pathological findings were consistent with BOOP, except for the moderate-to marked infiltration of lymphocytes. A lymphoproliferative disorder was suspected, and Southern blot analysis of the specimen revealed a rearrangement of the TCR-beta gene, which led to the diagnosis of T cell lymphoma. Ten months after the diagnosis, no recurrence of the lymphoma had been detected. In this case a gene analysis of the biopsy specimen was very useful for the diagnosis of T cell lymphoma.

[Chest wall reconstruction using polyester mesh].

From January 1987 through December 1994, we performed chest wall reconstruction using the polyester mesh in 15 patients with lung cancer, 11 with empyema after open drainage, 8 with chest wall tumor and 1 with radiation dermatitis and costal chondritis. Twenty five patients were resected 3 or more ribs. Chest wall defects were reconstructed with the polyester mesh covered with Gore-Tex soft tissue patch. Twenty two cases passed more than a year without signs of infection and follow-up averaged 27.6 months. Polyester mesh was removed due to bronchial fistula (3 cases), deformities (3 cases) and abscess formation (1 case). In these cases, polyester mesh was well incorporated and had no foreign body change. In conclusion, the polyester mesh seems to be a dependable prosthetic material for chest wall reconstruction.

[Positive expression of c-myc and p53 products in two cases of pulmonary sclerosing hemangioma].

The c-myc and p53 genes are thought to be an oncogene and a tumor suppressor gene, respectively. These genes' products are characteristic of malignant tumors. We quantitatively analyzed the c-myc and p53 products by flow cytometry in two cases of pulmonary sclerosing hemangioma. In case 1, 32.3% of the tumor cells were found to have the c-myc product, and 8.9% were found to have the p53 product. In case 2, 6.7% of the tumor cells were found to have the c-myc product and 15.5% were found to have the p53 product. The percentages in both cases were twice as high as those in a negative control lymphocytes stained with c-myc and p53 products. Therefore, these two cases showed positive expression of the c-myc and p53 products. In addition DNA from six other patients with sclerosing hemangioma was analyzed with paraffin-embedded sections. All six had DNA diploidy, with DNA indexes ranging from 0.91 to 1.03 and coefficients of variation ranging from 3.0 to 5.5. We suggest that pulmonary sclerosing hemangioma is a very weakly malignant tumor.

[Detection of loss of heterozygosity by microsatellite probe and DNA content analysis].

We examined replication error (RER) and loss of heterozygosity (LOH) in the region of microsatellites in 60 cases of resected lung cancer. We used microsatellite probes for the short arm of the 2nd chromosome (D2S123, D2S136), the short arm of the 3rd chromosome (D3S1067), and the short arm of the 17th chromosome (TP53). According to stage, the frequency of LOH was 25% in stage I, 33% in stage II, 44% in stage IIIA, 11% in stage III B, and 63% in stage IV. According to histological classification, the frequency of LOH was 41% for squamous cell carcinoma, 24% for adenocarcinoma, and 100% for small cell carcinoma. According to microsatellite probe results, the frequency of LOH was 6.7% for D2S123, 5.0% for D2S136, 16.7% for D3S1067, and 18.3% for TP53. Two of the 60 cases showed RER. One case was stage I squamous cell carcinoma, and the other was stage IV adenocarcinoma. Except for stage III B,LOH in the microsatellite region increases with the stage. LOH is often detected in the order of small cell carcinoma, squamous cell carcinoma, and adenocarcinoma. According to the chromosome number, LOH is detected more often in the 3rd and 17th chromosomes than in the 2nd chromosome. In 20 cases with LOH, only two showed DNA diploidy. Compared to LOH of the microsatellite region, DNA content analysis by flow cytometry has accuracy problems.

[The result of reoperation for lung cancer].

Twenty four patients with recurrent or multiple lung cancer were reoperated in our center. Five-year survival rate was 20% for 11 patients with recurrent, while was 25% for 13 patients with multiple after reoperation. The patients with limited operation had well survival and there was no significant difference in procedure. However all four patients with N2 had poor prognosis. Seven patients (29%) had the post reoperative complication in pulmonary system. All of them had the impairment of pulmonary function (FEV1.0% was less than 50%) or more than 75% perfusion ratio, measured with pulmonary perfusion scintigraphy, in the side of the reoperation.

[A case of solitary plasmacytoma of the chest wall].

A 58-year-old man with a solitary plasmacytoma of the chest wall is reported. He was admitted because of a painless tumor on the right lateral chest wall. The chest CT scan showed a chest wall tumor surrounding the 7th and 8th ribs without rib destruction. A transcutaneous needle biopsy of the tumor with a Sure-Cut-Needle revealed a plasmacytoma. The bone marrow biopsy findings were normal. Under a diagnosis of solitary plasmacytoma, the chest wall tumor was resected. The tumor was an extramedullary plasmacytoma. Southern blot analysis of the immunoglobulin light chain gene of the tumor cells detected a rearrangement of genes in the lambda chain, while no rearrangements of immunoglobulin genes were detected in the bone marrow specimen. Seven months later another solitary plasmacytoma was found at the left radius, and was resected. Southern blot analysis of the immunoglobulin light chain gene was useful in the differential diagnosis from systemic myeloma and in determining the monoclonality of the tumor.

[DNA content analysis and detection of c-myc and p53 products using flow cytometry in resected lung cancer cases].

We quantitatively analyzed the c-myc and p53 products using flow cytometry in 28 cases of resected lung cancer and one case each of chorio-carcinoma, plasmacytoma, malignant mesothelioma and sclerosing hemangioma. In the lung cancer cases, c-myc and p53 products were detected in 10 cases (35%) and 7 cases (21%), respectively. These rates are higher than the DNA abnormal expression rates of the c-myc and p53 genes (15% and 12%, respectively) in our own data. In the adenocarcinoma of lung cancer cases, c-myc and p53 products were detected in 9 cases (53%) and 5 cases (29%), respectively. Among the squamous cell carcinoma cases, there were one case (11%) of c-myc expression and one case (11%) of p53 expression. DNA content analysis of the lung cancer patients revealed 7 cases of DNA diploidy and 21 cases of DNA aneuploidy. All 10 c-myc-positive cases showed DNA aneuploidy; thus the positive rate for c-myc products in the DNA aneuploidy cases was significantly different compared with the DNA diploidy cases (p < 0.05). In the sclerosing hemangioma case, we detected both c-myc and p53 products. Sclerosing hemangioma has been thought to be a benign tumor, but it may be a malignant tumor.

[Preoperative staging in T1 and T2 lung cancers by mediastinoscopy and mediastinal lymph node dissection].

Between 1975 and 1992, mediastinoscopy and thoracotomy were performed on 184 T1 and 271 T2 lung cancer cases consisting of adenocarcinoma and squamous cell carcinoma. Mediastinoscopy gave true negative findings in 90.8% of the T1 patients, true positive findings in 7.6% and false negative findings in 1.6%. The comparable rates were 76.7%, 17.0% and 6.3% in T2 patients. The 5-year survival rate was 91.3% for T1N0M0 patients (n = 64) who underwent non-radical dissection (= NRD), and 69.4% for those (n = 70) who underwent radical dissection (= RD). The rate with NRD was significantly better (p < 0.006). The 5-year survival rate was 63.2% for T2N0M0 patients (n = 62) undergoing NRD, and 49.8% for those (n = 72) undergoing RD, but the difference was not significantly. Distant metastasis was a common cause of death, whereas there were no deaths due to local recurrence in the T1N0M0 patients, whether NRD or RD was performed. These results support our opinions that preoperative mediastinoscopy and intraoperative node staging are sufficient for assessment of the N factor in T1 and T2 lung cancer, and that mediastinal node dissection should not be performed in T1N0M0 patients.

[Diagnosis of mediastinal neoplasms using mediastinoscopy and CT-guided needle biopsy supported by gene analysis].

Of 140 cases of mediastinal neoplasms in our hospital, histological diagnosis was confirmed in 129 cases. We examined the methods of preoperative biopsy with those 129 cases. Biopsy had been performed in 25 cases. Mediastinoscopy was performed in seven cases, needle biopsy in eight cases, lymph node biopsy in eight cases, esophageal biopsy using a gastrofiberscope in one case, transbronchial biopsy using a bronchoscope in one case. The true positive rates of those methods were 100% for both mediastinoscopy and lymph node biopsy, and 75% for needle biopsy. Preoperative misdiagnosis occurred in two cases of needle biopsy. The postoperative histological diagnosis was malignant lymphoma in both cases. We performed gene analysis of the immunoglobulin heavy chain gene, light chain kappa and lambda genes, and the T-cell receptor beta gene by use of biopsied specimens, and we found rearrangement bands of these genes in the cases of malignant lymphoma. Therefore, we summarize that gene analysis is a reliable method if malignant lymphoma is suspected. If a needle biopsy is performed under CT guidance, the needle is sure to puncture the tumor. We concluded, therefore, that if a tumor is located in the anterior mediastinum, CT-guided needle biopsy should be performed first of all. Mediastinoscopy is a useful method if the tumor is located in the mid-mediastinum.

[An autopsy case of primary pulmonary malignant lymphoma associated with right pulmonary infiltrative shadow and macroglobulinemia].

We experienced a patient with two peaks of elevated monoclonal IgM and IgA in the serum, and lambda type Bence-Jones protein in the urine. Chest X-ray films showed right pulmonary infiltrative shadow and effusion. The results of the autopsy of this patient revealed infiltration of malignant lymphoma cells in both lungs, but in no other organs. The results of immunohistochemical staining for L26. UCHL-1, IgM, IgA and lambda chain in this case led to the diagnosis of diffuse small cell type. B-cell lambda, IgM type malignant lymphoma. Gene analysis using bone marrow did not reveal any rearrangement bands for the heavy chain, light chain kappa and lambda, or TcR beta genes. Therefore, we concluded that malignant lymphoma cells had infiltrated only the bilateral lungs, causing a rare case of primary pulmonary malignant lymphoma with two monoclonal peaks of increased serum IgM and IgA.

[Correlation between DNA content and amplification of oncogenes (c-myc, L-myc, c-erbB-2) and correlation with prognosis in 143 cases of resected lung cancer].

DNA content analysis using flow cytometry and amplification of c-myc, L-myc, and c-erbB-2 oncogenes in 143 cases of resected lung cancer were analyzed using the same specimen, and we examined the correlation with prognosis of DNA content and amplification of oncogenes. There were 54 DNA diploid cases (38%), 81 DNA aneuploid cases (57%) and 8 DNA multiploid cases. Analysis of oncogene amplification revealed 22 cases of c-myc, 4 cases of L-myc, and 22 cases of c-erbB-2. In curatively resected cases, the 5-year survival rate was 65% in 31 DNA diploid cases, and 36% in 40 DNA aneuploid cases. There was a statistically significant difference between the two groups (p < 0.02). However, in non-curatively resected cases, the 5-year survival rate was 11% in 23 DNA diploid cases, and 33% in 49 DNA aneuploid cases. There were no statistically significant differences among these groups. The correlation between DNA content and amplification of oncogenes was as follows. In DNA diploid cases, there were 4 cases of c-myc, and 6 cases of c-erbB-2. In DNA aneuploid cases, there were 15 cases of c-myc, 4 cases of L-myc, and 15 cases of c-erbB-2. In DNA multiploid cases, there were 3 cases of c-myc, and 1 cases of c-erbB-2. Amplification of oncogenes was seen more frequently in DNA aneuploid and multiploid cases than in DNA diploid cases. In 71 curative resected cases, the 5-year survival rate for amplified cases of c-myc (10 cases) was 0%, and that of cases with no amplification was 61% (no statistically significant difference). The 5-year survival rate for amplified cases of c-erbB-2 (10 cases) was 40%, against 52% for cases with no amplification. DNA content analysis using flow cytometry was more convenient than analysis of amplification of oncogenes, and reflects the prognosis of resected lung cancer better than oncogenes. There was no relation between DNA content and gene amplification.