Immunolocalization of inducible nitric oxide synthase in localized juvenile periodontitis patients.

Localized juvenile periodontitis (LJP) is associated with a destruction of periodontal tissues and the presence of Actinobacillus actinomycetemcomitans (AA). Lipopolysaccharide (LPS) from AA was found to induce a significant macrophage production of nitric oxide (NO). Increased nitric oxide synthase (NOS) activity was found to be negatively correlated with the neutrophil chemotactic response. The aim of this study was to determine the occurrence and distribution of inducible NOS (iNOS) in human gingival tissue from LJP patients. The distribution of iNOS was assessed by monoclonal antibody against iNOS. Cellular markers (CD 3, CD 20, and CD 68) were used to determine the cellular origin of iNOS. The immunostaining revealed the appearance of iNOS in inflamed compared to noninflamed gingival tissues. Macrophages expressed high levels of iNOS that may cause some damage to the periodontal tissues. This study suggests that iNOS activity in macrophages may modify abnormalities of neutrophil function.

Incidental prostatic carcinoma. A predictive role of neoangiogenesis and comparison with other prognostic factors.

Incidental prostatic carcinoma (ICP) has good prognosis related to low stage at diagnosis. Few rogressive cases demanding aggressive treatment need early identification. Neoangiogenesis proved its predictive role in prostatic carcinoma after radical prostatectomy. To reveal its value in ICP authors investigated specimens after transurethral resection of prostate (TURP). Retrospective study was performed on 68 ICP diagnosed in years 1985 1989. Microvessels highlighted by factor VIII were counted in a x200 microscope field (0,8012 mm 2 ) in most active areas of neovascularisation. Microvessel count was correlated with tumor differentiation degree, Gleason score, disease stage, and patients survival in at least 9 years after diagnosis. Higher maximal microvessel counts were associated with lower degree of tumor differentiation (p=0,005), Gleason score (p=0,001), and disease stage (0,003). No association with disease progression and patients survival was found. Mean microvessel counts showed less significant values when correlated with tumor differentiation degree (p=0,003) and Gleason score (p=0, 01), and no correlation with other variables. Microvessel density in TURP specimens of ICP retains its prognostic value already demonstrated in carcinoma of peripheral prostatic lobes. Maximal microvessel counts were prognostically more reliable than mean values.

VHL alterations in human clear cell renal cell carcinoma: association with advanced tumor stage and a novel hot spot mutation.

To elucidate the role of somatic alterations for renal cancer etiology and prognosis, we analyzed 227 sporadic renal epithelial tumors for mutations and hypermethylations in the von Hippel-Lindau tumor suppressor gene VHL. Tumors were classified according to the recommendations of the Union Internationale Contre le Cancer (UICC) and the American Joint Committee on Cancer (AJCC). Somatic VHL mutations were identified by PCR, single-strand conformation polymorphism analysis, and sequencing, and hypermethylations were identified by restriction enzyme digestion and Southern blotting. Frequencies of VHL alterations were established, and an association with tumor type or tumor type and tumor stage was evaluated. VHL mutations and hypermethylations were identified in 45% of clear cell renal cell carcinomas (CCRCCs) and occasionally (3 of 28) in papillary (chromophilic) renal cell carcinomas (RCCs). Lack of VHL mutations and hypermethylations in chromophobe RCCs and oncocytomas was statistically significant (P = 0.0001 and P = 0.0004, respectively). RCCs carrying VHL alterations showed, in nine cases (12%), mutations at a hot spot involving a thymine repeat (ATT.TTT) in exon 2. Tumor staging was critical to the VHL mutation/hypermethylation detection rate in CCRCCs shown by separate evaluation of patients from medical centers in Munich, Heidelberg, and Mainz. The spectrum of pT1, pT2, and pT3 CCRCCs and the VHL mutation/hypermethylation detection rate varied among these three groups. Altogether, VHL alterations were significantly associated with pT3 CCRCCs (P = 0.009). This is the first evidence of frequent somatic VHL mutations at a particular site within exon 2 and an association of VHL mutations/hypermethylations with a standard prognostic factor.

Effect of pH on Ki-67 antigen retrieval in renal cell carcinoma.

The efficacy of Ki-67 antigen retrieval (AR) was assessed in 20 formalin fixed-paraffin embedded specimens of renal cell carcinoma using three solutions with different pH values. The AR was performed by means of microwave oven heating up to 97 degrees C for 15 minutes. Better results were obtained using solutions with pH values 8.0 and 9.9 compared with AR in a solution of pH 6.0, which is routinely used in daily pathological practice. Individual testing of various AR conditions is recommended to obtain the best immunohistochemical results.

Angiosarcoma of the testis.

A primary angiosarcoma of the testis in a 74-year-old patient was a highly anaplastic epthelioid angiosarcoma, which was positive for endothelial markers immunohistochemically. The tumour was unrelated to testicular germ cell neoplasm; the patient had received no previous radiation or chemotherapy.

Tumor neoangiogenesis in rebiopsied patients with prostatic carcinoma.

Tumor neoangiogenesis has proven its prognostic value in malignant tumors of different organs including prostatic adenocarcinoma. The aim of this retrospective study was to disclose the significance of neoangiogenesis in incidental prostatic carcinoma (ICP) after transurethral resection (TURP). The authors examined all patients having ICP diagnosed at the Institute of Pathology, Medical Faculty in Ljubljana during the 1985-1989 period, in whom rebiopsy was performed. Ten of 68 patients were examined to determine how microvessels correlate with the degree of tumor differentiation determined histopathologically, and with Gleason score, stage of disease, and survival time. Microvessels were highlighted by immunostaining endothelial cells for factor VIII-related antigen and counted in a x200 microscope field (0.8012 mm2) in the most active areas of neovascularization. Neoangiogenesis and tumor differentiation degree were then correlated between primary tumors and rebiopsies. Tumor differentiation degree was also correlated with the time of the disease progression. Microvessel counts (MVC) showed no association with the degree of tumor differentiation, Gleason score, disease stage, or patients' survival. The time elapsed to the disease progression was associated with less differentiated tumors (p = 0.004; 0.006). Microvessel counts were significantly higher in rebiopsies compared to initial tumors (p = 0.006), but no differences could be observed in the degree of differentiation. The results showed that the determination of microvessel density in rebiopsied patients had a better prognostic value than the degree of tumor differentiation. Nevertheless, the latter showed an association with the time of the disease progression. The number of patients included in the study was too low to confirm the association of MVC and degree of tumor differentiation in primary tumors.

Angiomyolipoma of the kidney--an immunohistochemical study.

The study included 25 patients with angiomyolipoma of the kidney. None of them had any signs of tuberous sclerosis. Serious clinical complications such as massive hemorrhage (2/25) and hydronephrosis (2/25) were documented in four patients. Concomitant adenoma of the adrenal gland and renal cell carcinoma were found in one patient each. All tumors consisted of a differing mixture of mature adipose tissue, smooth muscle cells and blood vessels, with thickened walls devoid of elastic lamina. Immunohistochemically, the smooth muscle cells stained strongly with antibodies against vimentin, desmin and actin, as well as HMB-45 and NKI/C3. Immunohistochemical staining for NKI/C3 was stronger and more diffusely distributed. These two markers proved to be very useful in the diagnosis of angiomyolipoma, when only needle biopsy specimens are available.

Uroplakins and cytokeratins in the regenerating rat urothelium after sodium saccharin treatment.

A sodium saccharin (NaSac) diet was used to induce cell damage and regeneration in the urothelium of the male rat urinary bladder. Foci of terminally differentiated superficial cell exfoliation were detected after 5 weeks and their number increased after 10 and 15 weeks of the diet. At the sites of superficial cell loss, regenerative simple hyperplasia developed. Within 5 weeks of NaSac removal, regeneration re-established normal differentiated urothelium. In order to follow urothelial differentiation during regeneration we studied the expression of uroplakins and cytokeratins by means of immunocytochemistry and immunohistochemistry, respectively. Normal urothelium was characterised by terminally differentiated superficial cells which expressed uroplakins in their luminal plasma membrane and cytokeratin 20 (CK20) in the cytoplasm. Basal and intermediate cells were CK20 negative and cytokeratin 17 (CK17) positive. In hyperplastic urothelium all cells synthesised CK17, but not CK20. Differentiation of the superficial layer was reflected in three successive cell types: cells with microvilli, cells with rounded microridges and those with a rigid-looking plasma membrane on the luminal surface. The cells with microvilli did not stain with anti-uroplakin antibody. When the synthesis of uroplakins was detected rounded microridges were formed. With the elevated expression of uroplakins the luminal plasma membrane becomes rigid-looking which is characteristic of asymmetric unit membrane of terminally differentiated cells. During differentiation, synthesis of CK17 ceased in superficial cells while the synthesis of CK20 started. These results indicate that during urothelial regeneration after NaSac treatment, specific superficial cell types develop in which the switch to uroplakin synthesis and transition from CK17 to CK20 synthesis are crucial events for terminal differentiation.

Sudden death caused by laryngeal papillomatosis.

Laryngeal papillomatosis (LP) is the most frequent benign neoplasm of the larynx. Clinically it causes hoarseness and upper airway obstruction. Though the LP has the potential to endanger life by asphyxiation, this unfortunate outcome is extremely rare. We report the case of a 19-year-old female who suddenly died of asphyxiation caused by massive LP.

Genetic changes in the origin and development of renal cell carcinoma (RCC).

64 kidney tumours of clear cell histopathology were analysed with non-isotopic SSCP and HA for the presence of VHL gene defects. All positive cases were further characterised by direct sequencing. In 30 tumours (48%) mutations were identified in the coding region of the VHL gene. Other tumours were examined for methylation changes in 5' CpG islands in exon 1 Bisulphite genomic sequencing which gives positive signal for methylated cytosines, was used in this analysis and in 7 tumours hypermethylation of 5' CpG islands was found. These findings suggest that VHL gene mutations together with methylation associated inactivation of the VHL gene are important events that predispose to renal cell tumorigenesis.

Primary carcinoid of the kidney.

A case of primary carcinoid tumour of the kidney in a 40-year-old man is reported. It was initially diagnosed as a Wilms' tumour monomorphic type. After total unresponsiveness to specific therapy, specimens were reexamined and immunohistochemical and electron microscopic examinations were also employed disclosing the real nature of the tumour which showed cytoplasmic positivity for neuron-specific enolase in tumour cells and presence of numerous electron dense core neuroscretory granules in their cytoplasm.

Malignant fibrous histiocytoma of the heart.

We describe a 54-year-old man with a recurrent malignant fibrous histiocytoma in the left atrium. During the patient's first hospitalization, the tumor clinically presented as a typical atrial myxoma and was removed by routine procedure. Histologically, it was diagnosed as sarcoma, probably rhabdomyosarcoma. Nine months later the patient was readmitted because of recurrence. This time, the tumor, along with interatrial septum and a part of the anterior atrial wall, was excised by means of cardiac explantation and reimplantation. On light microscopic, immunohistochemical, and electron microscopic examination, the tumor was classified as a storiform-pleomorphic type of malignant fibrous histiocytoma. No other therapeutic procedures were performed, and 11 months after the second surgery the patient died of massive hemorrhage from a duodenal ulcer. A recurrent tumor in the left atrium and several distant metastases were found at autopsy.

Synovial sarcoma of the soft palate in a child: a light and electron microscopic study.

An extremely rare case of synovial sarcoma localized in the soft palate of a 9-year-old boy is reported, describing all details noted during light and electron microscopic observation. All features characteristic of this mesenchymal tumour were evident in the light microscopy. Electron microscopy also confirmed the diagnosis. The text includes full particulars of the therapy administered.