Epidemiological study of intraosseous lesions of the stomatognathic or maxillomandibular complex diagnosed by a Reference Centre in Brazil from 2006-2017.

This epidemiological study was designed to find out the incidence and factors associated with the occurrence of intraosseous lesions diagnosed at a Reference Centre in Brazil. We included all patients diagnosed with intraosseous lesions (cyst, tumour, bone-associated lesion, and periapical disease) during the period 2006-2017, and analysed the association between some sociodemographic and clinical variables and the types of lesion. There was a total of 290 intraosseous lesions, the most common being odontogenic cysts. There was a significant association between age and odontogenic tumours (p=0.001). In relation to the histopathological diagnosis, root cysts were the most common (n=57), followed by dentigerous cysts (n=26). The lesions studied were seen most often in women between the second and fourth decades of life, odontogenic cysts being the most common type found. We know of few publications of similar epidemiological work, either in Brazil or in the rest of the world, so we suggest that more such studies are made.

Mutational analysis of the tumor-suppressor gene wt1 - detection of a novel homozygous point mutation in sporadic unilateral wilms-tumor.

The WT1 gene located on chromosome 11p13, has been identified as the first Wilms' tumor suppressor gene and has been implicated in the development of Wilms' tumor. About 10% of Wilms' tumors analyzed to date carry a mutation and only 6 different point mutations affecting the zinc finger region have been reported. We analyzed the zinc finger coding exons of 38 sporadic Wilms' tumor by SSCP and detected 2 point mutations. One homo/hemizygous mutation, already described in the literature, replaced an arginine in zinc finger II by a stop codon. The other mutation, a replacement of an arginine by a stop codon in zinc finger I, represents a novel mutation.

Human herpesvirus type 6 and cytomegalovirus in AIDS-associated Kaposi's sarcoma: no evidence for an etiological association.

Epidemiological studies indicate that acquired immune deficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS) may be caused by an infectious, preferentially sexually transmitted agent. Herpesviruses infections are common sexually transmitted diseases in homosexual men, who are also the main risk group for developing Kaposi's sarcoma. To evaluate a possible role of human herpesvirus-6 (HHV-6) and cytomegalovirus (CMV) in the development of AIDS-associated KS, we investigated cutaneous AIDS-associated KS in 26 AIDS patients using the polymerase chain reaction (PCR) and immunohistochemistry (IHC) to detect the presence of HHV-6 and CMV. Human herpesvirus-6 was detected in nine of 26 Kaposi's sarcoma specimens (all cases were HHV-6 subtype B) and in eight of 27 normal skin specimens from human immunodeficiency virus (HIV) seropositive and HIV seronegative patients (one case was HHV-6 subtype A and seven cases were HHV-6 subtype B). In two of four patients showing HHV-6 in KS of the skin, the virus also was detected in other investigated tissues, such as heart, lung, liver, kidney, and adrenals. Cytomegalovirus was detected only in AIDS-associated KS (seven of 26 KS specimens) and not in normal skin tissues of HIV-seropositive and HIV-seronegative patients. Cytomegalovirus was detected in other organs of those patients showing CMV in Kaposi's sarcoma. Our data indicate that the presence of HHV-6 and CMV in AIDS-associated KS most likely reflects disseminated viral infection. Human herpesvirus-6 and CMV may be cofactors but not the only causative agents for the development of AIDS-associated KS.

Detection of t(11;22)(q24;q12) translocation breakpoint in paraffin-embedded tissue of the Ewing's sarcoma family by nested reverse transcription-polymerase chain reaction.

Tumors of the Ewing's sarcoma family often present a major diagnostic challenge for the pathologist. In recent years, significant progress has been made in identifying characteristic chromosomal rearrangements associated with certain solid tumors. More than 85% of Ewing's sarcoma and related tumors present a specific t(11;22) (q24;q12) balanced translocation, which generates a fusion transcript of the EWS gene and the FLI-1 gene. The cloning of the t(11;22)(q24;q12) breakpoint has raised the possibility of using a reverse transcription-polymerase chain reaction (RT-PCR) based assay as a diagnostic tool. We report an improvement of the established method, which currently depends on fresh or snap-frozen tissue, so that it is possible to use formalin-fixed, paraffin-embedded tissue as a source of RNA. The described nested RT-PCR assay enables the pathologist to investigate retrospectively archival tumor samples or to confirm the diagnosis in cases where no fresh or frozen material is available.

Specific diagnosis of parvovirus enteritis in dogs and cats by in situ hybridization.

In a retrospective study, the fixed intestines of 10 dogs and 10 cats with intestinal lesions characteristic of parvovirus infection were assayed for the presence of parvovirus by in situ hybridization and immunohistochemistry. Parvoviral nucleic acid was localized by in situ hybridization in intestinal tissue in all 10 dogs and in nine of the 10 cats, whereas antigen was detected only in seven of 10 canine and eight of 10 feline intestines by immunohistochemistry. We conclude that an aetiological diagnosis can be established with a high degree of certainty by routine histology. Demonstration of the infectious agent by in situ hybridization, however, proves to be a valuable specific tool which allows an exact cellular localization of parvovirus in formalin-fixed, paraffin wax-embedded tissue sections.

The elimination of mouse hepatitis virus by temporary transplantation of human tumors from infected athymic nude mice into athymic nude rats (rnuN/rnuN).

A nude mouse colony held in an isolation unit was found to harbor MHV despite the fact that all hygienic precautions were taken. The virus spread rapidly causing a high mortality rate predominantly in experimental animals. Moreover, we observed a high percentage of tumor regression in our tumor transplanted mice. Attempts to eliminate the MHV by repeated tumor transplantation into virus-free nude mice were unsuccessful. Since MHV has a limited host range, we transplanted, in parallel, four different lines of embryonic renal tumors (three triphasic nephroblastomas and one malignant rhabdoid tumor of the kidney) from athymic mice into athymic rats and fragments of the same tumors into "fresh" nude mice. All manipulations were performed in isolators. Detection of MHV was done twice by serological examination of six-week-old sentinels. The results showed transmission of MHV infection in the control mice under gnotobiotic conditions as previously found in the normal animal room. On the other hand, there was no evidence of infection, neither in the transplanted nude rats nor after retransplantation of tumors into nude mice. We hypothesize that the virus is harbored in the stromal cells of the murine host but not of the rat host nor in the human tumor cells. Histological comparison showed no alteration of specific tumor morphology in the different hosts.

Susceptibility to toxoplasmic retinochoroiditis is associated with HLA alleles reported to be implicated with rapid progression to AIDS.

BACKGROUND/AIMS: The frequency of HLA markers associated with rapid progression to AIDS was evaluated in Brazilian patients with AIDS exhibiting or not toxoplasmic retinochoroiditis (TRC). METHODS: 98 AIDS patients (25 with TRC, 43 with anti-T. gondii antibodies but without TCR, and 30 without anti-T. gondii antibodies and without TCR) were studied. RESULTS: The HLA-B35 was significantly increased in TRC group (p=0.0038). CONCLUSION: The presence of HLA-B35 may simultaneously predispose to progression to AIDS and TRC.

Anterior urethral valve--an [corrected] uncommon cause of urethral obstruction.

An anterior urethral valve causing bladder outlet obstruction in children is rare. The early identification and management of this condition is crucial as delay may lead to chronic renal damage. We present a case of a 10-month old male child diagnosed with an anterior urethral valve by micturating cystourethrogram. This case emphasizes the importance of visualizing the whole of the penile urethra in performing a paediatric MCU examination or this important diagnosis may be missed.

[Detection of the intermediate trophoblast as evidence of intrauterine pregnancy]. / Nachweis des intermediären Trophoblasten als Beleg einer intrauterinen Schwangerschaft.

With spontaneous abortion the conceptus is often expelled and lost right at the beginning, and uterine curettings then contain only endometrial fragments and clotted blood. Even complete embedding of all available material for histologic examination will not reveal any chorionic villi, and ectopic pregnancy can thus not be excluded. In such cases, the intermediate trophoblast can sometimes still be demonstrated within the endometrial tissue. This highly invasive trophoblast is difficult to identify using conventional staining, but cytokeratin antibodies are reliable markers of this cell type. Using immunohistochemistry, these fetal components could be demonstrated in 27 of 95 specimens (28.5%), proving the intrauterine nature of the aborted pregnancy. In some cases the fetal derivation of intermediate trophoblast was demonstrated by using in situ hybridisation to mark repetitive sequences on the Y-chromosome in the interphase nucleus.

[Demonstration of the differential expression of IGF-II in various embryonal kidney tumors using slot-blot hybridization and in-situ hybridization]. / Nachweis der unterschiedlichen Expression von IGF-II bei verschiedenen embryonalen Nierentumoren durch slot-blot-Hybridisierung und in-situ-Hybridisierung.

IGF-II may play a decisive role in the development of Wilms tumors since an elevated expression of this important embryonal growth factor has been reported in the majority of nephroblastomas. In our series of 15 typical triphasic or blastemal predominant nephroblastomas slot-blot-hybridization revealed a marked increase of IFG-II-mRNA in the tumor tissue of 11 patients. Compared to normal kidney tissue IGF-II-expression was elevated up to 64 times. Apart from nephroblastoma a number of other embryonal renal tumors with either a much better or much worse prognosis was investigated. A moderately increased expression of IGF-II was noted in 2 congenital mesoblastic nephromas. IGF-II-mRNA was only slightly increased in a clear cell sarcoma of the kidney but was not elevated in 2 malignant rhabdoid tumors of the kidney. In-situ-hybridization allowed precise localization of the markedly increased IGF-II mRNA to blastemal cells. Differentiation to epithelial structures such as tubules or glomeruli or to stromal cells was associated with a marked loss in IGF-II expression.

Determination of hexokinase isoenzyme I and II composition by RT-PCR: increased hexokinase isoenzyme II in human renal cell carcinoma.

Hexokinase isoenzyme composition has been noted to vary in different tissues and with the developmental and metabolic status of the cell. Until now these investigations were performed either by isoenzyme electrophoresis or by column chromatography. In this report we described an RNA-PCR method to evaluate the percentage of HK-1 and HK-2 in different rat tissues. Furthermore we applied the method to determine if a shift in isoform composition is detectable in human renal carcinomas compared to normal kidney tissue. In all of our specimens we were able to detect a shift toward HK-2 in the carcinoma specimens. We discuss a possible role for the detection of the shift in isoenzyme composition as a possible marker to discriminate between normal and malignant specimens.

[Increased expression of IGF-2 in tumor tissue of nephroblastoma]. / Nachweis erhöhter Expression von IGF 2 im Tumorgewebe von Nephroblastomen.

The incidence of nephroblastoma is increased in a number of syndromes with abnormal growth pattern. Elevated IGF 2-expression has been documented in various Wilms' tumors and a defect in the IGF 2 gene has been noted in 1 case. Southern blot analysis of genomic DNA of nephroblastomas in 5 additional patients after restriction enzyme digest with EcoRI, Pvu II, Pst I and Taq I did not reveal any defect in the IGF 2 gene. Slot blot analysis however showed marked overexpression of IGF 2-mRNA reaching up to more than 25 times the level expressed in unaffected kidney tissue adjacent to the tumor and in normal kidney tissue used as controls.

[Detection of human herpesvirus type 6, human herpesvirus type 7, cytomegalovirus and human papillomavirus in cutaneous AIDS-associated Kaposi's sarcoma]. / Nachweis von humanem Herpesvirus Typ 6, humanem Herpesvirus Typ 7, Zytomegalievirus und humanen Papillomviren in kutanen AIDS-assoziierten Kaposi-Sarkomen.

In order to evaluate a possible role of viral infections in the pathogenesis of AIDS-associated Kaposi's sarcoma (KS), we investigated 26 cutaneous AIDS-associated KS by polymerase chain reaction (PCR), in situ hybridization, and immunohistochemistry. By PCR we detected human papilloma viruses (HPV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), and for the first time human herpesvirus 7 (HHV-7) in the KS. The prevalence of HPV, HHV-6, and HHV-7 was similar to or lower in KS than in normal skin tissues of AIDS patients without KS, but higher than in normal skin of HIV-seronegative patients. All HHV-6 found in KS were identified as HHV-6 variant B. In addition to the known HPV types 16 and 18 described in KS, we also found HPV types 6 and 33 in KS specimen. By immunohistochemistry HHV-6 could be localized in macrophages in KS, in the adjacent stroma as well as in normal skin of control cases. In situ hybridization for CMV and HPV gave negative results in KS and controls.

Systemic effects of insulin-like growth factor-II produced and released from Wilms tumour tissue.

The concentration of mRNA of insulin-like growth factor-II is (IGF-II) much elevated in some embryonic tumours such as Wilms tumour (nephroblastoma). In order to prove whether or not IGF-II is produced by the tumour tissue, IGF-II was extracted from freshly frozen tissue of Wilms tumour and hepatoblastoma. Normal adjacent tissue of kidney and liver was used as a control. The total IGF-II in Wilms tumour was 548.4 +/- 77.4 ng/g (n = 7) compared to 112.8 +/- 38.2 ng/g (n = 5) in kidney. In two hepatoblastomas, it was 96.1 +/- 22.8 ng/g compared to 30.1 +/- 14.2 ng/g in normal liver. Small pieces of fresh primary tissue of several Wilms tumours were successfully transplanted into immunodeficient nude mice. In serum of tumour-bearing mice IGF-II was elevated compared to normal mice. Liver weight of tumour bearing mice was higher than that of control mice (2.29 +/- 0.4 g and 2.02 +/- 0.06 g; P < 0.005). This was also found for kidney weight (0.58 +/- 0.01 g vs. 0.51 +/- 0.01 g in controls, P < 0.001). In contrast, serum glucose (9.73 +/- 0.29 mmol/l compared to 11.80 +/- 0.42 mmol/l in controls, P < 0.0005) was decreased. However, there was no significant difference in nose-tail length of tumour-bearing compared to control mice. These results demonstrate that besides the highly increased IGF-II-mRNA, the synthesis of the peptide IGF-II and its release into circulation are also elevated in Wilms tumour transplanted into nude mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of several types of human papilloma viruses in AIDS-associated Kaposi's sarcoma.

Epidemiological studies indicate that acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS) may be caused by an infectious, preferentially sexually transmitted agent. Infections with human papilloma viruses are common, sexually transmitted diseases occurring frequently in homosexual men, who are also the main risk group for developing KS. In order to evaluate the possible role of HPV in the development of KS, 24 cutaneous AIDS-associated Kaposi's sarcomas were investigated by the polymerase chain reaction (PCR) and by in situ hybridization for the presence of human papilloma viruses (HPV). HPV DNA sequences were detected in 5 of 24 KS specimens, in 4 of 13 normal skin specimens from AIDS patients without KS and in 5 of 14 skin specimens of HIV-seronegative patients. For the first time, HPV types 6 and 33 were detected by PCR in KS. A higher proportion of HPV types 16/18 was found in AIDS-associated KS specimens, whereas HPV type 33 was seen more often in normal skin specimens of the control group. Apart from the known HPV types 16/18 described in KS, this study demonstrates also the presence of HPV 6 and 33 in this condition.

[T-cell rich B-cell lymphoma associated with hemophagocytic syndrome]. / T-Zell reiches B-Zell Lymphom assoziiert mit hämophagozytischem Syndrom.

Report of a T-cell rich B-cell lymphoma (TCRBCL) in a 43 years old man with an associated haemophagocytic syndrome (HS). At presentation the haemophagocytic cells involved the same organs as the lymphoma, i.e. spleen, liver, abdominal lymph nodes and bone marrow. As supportive measure to alleviate chemotherapy-induced granulocytopenia the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) was given. After an initial improvement of the blood granulocyte count pancytopenia developed again, resulting in fatal sepsis. Autopsy demonstrated massive proliferation of macrophages in the bone marrow with haemophagocytosis as morphological correlation to the pancytopenia. The observation that exogenous GM-CSF enhanced the preexistent HS primarily reactive to the TCRBCL raises the question if endogenous GM-CSF may play a role in triggering a HS. The observed association of TCRBCL and HS has not been reported so far.

In situ hybridization for the detection of human parvovirus B19 nucleic acid sequences in paraffin-embedded specimens.

Parvovirus infection of pregnant women leading to a transplacentar infection of the fetus may result in hydrops fetalis, and ultimately in intrauterine death of the fetus. In situ hybridization with a biotinylated as well as with a 35S-labeled probe for human parvovirus B19 was performed on formalin-fixed paraffin-embedded (FFPE) tissue from a fetus suffering from non-immunologic hydrops fetalis. Histology was suggestive of viral infection probably with human parvovirus. Parvovirus DNA could be detected and precisely localized mainly in the nuclei of erythroid precursors cells within fetal blood vessels of all organs examined. There was no detection of B19 nucleic acid in parenchymal cells of the placenta or the fetal organs, nor within maternal blood cells. These findings are in agreement with the well-known properties of animal parvoviruses to replicate exclusively in proliferating cells. Taking into consideration the problems in diagnosing human parvovirus infection by light microscopy, we conclude that in situ hybridization with an appropriate non-radioactive probe is a valuable, rapid and safe complementary detection method for the diagnosis and study of human parvovirus infections. The 35S-labeled probe is more sensitive than the biotinylated probe, but has the disadvantages of lower resolution of the signal, longer duration of the assay, the hazard of radioactivity and the shorter shelf-life of the probe.

A realistic approach to the sensitivity of PCR-DGGE and its application as a sensitive tool for the detection of clonality in cutaneous T-cell proliferations.

The practical value of the detection of clonality within the T-cell receptor gamma locus by polymerase chain reaction for the diagnosis of cutaneous T-cell lymphomas is well known. However, studies dealing with this subject so far, with special emphasis on the sensitivity of the technique in comparison to, for example, Southern blotting have used mixtures of DNA in various concentrations instead of using mixtures of the cells involved, which would reflect the in vivo situation in a more realistic scope. The purpose of this study was therefore to determine the sensitivity and the limitations of the PCR assay by dilution experiments, using mixtures of cells. Furthermore we studied its applicability to cutaneous T-cell proliferative disorders. Two clonal T-cell lines (MyLa and Jurkat) served as positive control. Dilutions of MyLa cells, cultured normal human keratinocytes and peripheral blood mononuclear cells from lymphoma negative volunteers were used to assess the sensitivity of the PCR-DGGE assay. Skin samples from 4 patients with cutaneous T-cell lymphoma, 1 lesional lymph node, 2 blood samples from a patient with Sézary syndrome and 4 lymphoma-negative tissue samples were analysed. Two samples were uncertain for diagnosis of lymphoma. The PCR-DGGE assay consisted of a 2-round nested PCR with consensus primers within the TCR-gamma locus followed by electrophoretic separation of the product along a denaturing urea/formamide gradient gel. PCR-DGGE sensitivity was, to our knowledge, for the first time investigated for mixtures of lymphocytes (clonal and polyclonal) and keratinocytes. Clonal T-cells were detected in a concentration between 1-0.1% in keratinocytes, whereas the sensitivity was generally lower upon dilution in peripheral blood mononuclear cells or in a mixture of keratinocytes and peripheral blood mononuclear cells. Nevertheless, T-cell clonality was detected in 2 blood samples of a patient with Sézary syndrome, which were negative by Southern blot analysis. The crucial point of this work was the new approach to establish the sensitivity of the PCR-DGGE, in a way which more closely mimics the condition of clinical specimens. Instead of mixing and amplifying DNA extracted from clonal T-cell lines and polyclonal bone marrow cells, we amplified DNA from clonal and polyclonal cells which had been mixed in various ratios before DNA extraction. Polymerase chain reaction in conjunction with denaturing gradient gel electrophoresis is a sensitive and versatile molecular tool for the assessment of clonality of suspect cutaneous lesions. The determination of sensitivity using DNA extracted from premixed cells more closely corresponds to the actual test situation when testing skin samples.

Primary cutaneous T-cell-rich B-cell lymphoma. A case report with a 13-year follow-up.

Cutaneous B-cell lymphomas constitute approximately 20% of primary cutaneous lymphomas. Most histologic subtypes of nodal B-cell lymphomas also occur primarily in the skin. The recently described T-cell-rich B-cell lymphomas (TCRBCLs) manifest mainly in the lymph nodes. This article presents a case of TCRBCL arising primarily in the skin, the origin of which could be traced back 13 years. The patient is a 59-year-old man. Plaque-like and nodular skin infiltrates had first appeared in the left preauricular region. Repeated examinations never found any extracutaneous involvement. A skin biopsy and a retrospectively studied 10-year-old skin specimen showed identical histologic features. Immunohistochemistry identified the TCRBCL previously considered as cutaneous Hodgkin's disease or a diffuse centroblastic centrocytic non-Hodgkin's lymphoma. A clonal B-cell population was detected by polymerase chain reaction, showing a rearrangement of IgH gene. The case of this patient shows that primary cutaneous TCRBCLs, similarly to other B-cell lymphomas in the skin, may have a good prognosis, in contrast to their nodal counterparts.