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PubMedDate not supplied

Identification of multiple antigens recognized by tumor-infiltrating lymphocytes from a single patient: tumor escape by antigen loss and loss of MHC expression.

The authors describe a patient who experienced recurrence of metastatic melanoma after an initial dramatic response to immunotherapy using peptides derived from gp100, MART-1, and tyrosinase emulsified in incomplete Freund's adjuvant, and present data to support the hypothesis that the progression of disease in this patient was due to in vivo immunoselection for immunoresistant tumor variants. The authors previously demonstrated the existence of T-cell clones in this patient's peripheral blood and tumor-infiltrating lymphocytes (TILs) reactive against multiple antigens, including gp100, the tyrosinase-related protein (TRP)-2, a novel TRP-2 isoform-TRP-2-6b, SOX10, and the melanoma antigen NY-ESO-1. In addition to the multiple HLA-A2 restricted T-cell clones, the authors have now identified additional HLA-B/C-restricted as well as class II (HLA-DP)-restricted anti-melanoma antigen T-cell clones from this patient's TIL. One recurrent tumor showed loss of expression of multiple tumor antigens but retention of HLA class I expression. The other recurrent lesion showed total loss of HLA class I expression even though the tumor cells still expressed many melanoma antigens. This paper thus provides evidence for both the effectiveness of the immune destruction of cancer as well as problems associated with antigen-loss tumor escape mechanisms.

Antigens, Neoplasm↗
PubMed1998

Expression of CD44 and variant proteins in human colorectal cancer and its relevance for prognosis.

BACKGROUND: CD44 is a cell adhesion molecule often expressed in the form of various splice variants. The role of standard CD44 isoform (CD44s) and its variants in colorectal carcinogenesis is partly conflicting. Therefore, we compared the expression of CD44s (hermes-3) and its splice variants (v3 and v6) with traditional prognostic factors in 194 colorectal cancer patients treated at Kuopio University Hospital and followed up for a mean of 14 years. METHODS: Formalin-fixed, paraffin-embedded tissue sections from 194 patients with colorectal carcinoma were examined immunohistochemically to detect the expression of different forms of CD44. The hypothesis that CD44s, CD44v3, and CD44v6 expression intensities and distribution in cancer cells correlated with survival was tested with the log-rank test, hazard ratios, and their confidence intervals. RESULTS: In high-grade tumours CD44s and CD44v6 expression intensities and CD44s percentages were stronger than in low-grade tumours. CD44v6, CD44v3, and CD44s expression intensities in tumour epithelium were also stronger in Dukes C and D tumours than in A and B tumours. In the univariate survival analysis patients with strong CD44s, CD44v3, and CD44v6 expression intensities in tumour epithelium had lower cancer-related survival than the patients who had weak CD44s, CD44v3, and CD44v6 expression intensities. Recurrence-free survival was also shorter in patients with intense signals for CD44v3 and CD44v6 in tumour epithelium. In the multivariate analysis the CD44v6 expression intensity in tumour epithelium predicted independently both cancer-related and recurrence-free survival in T1-4N0-3M0 and T1-3N0M0 cases. In addition, the CD44v3 expression intensity in tumour epithelium was a significant predictor of RFS in T1-3N0M0 cases. CONCLUSIONS: These results strongly suggest that the CD44 splice variants v6 and v3 have prognostic significance in colorectal cancer.

Adult↗
PubMed1980

Dense core vesicles in the desmoplastic variant of cerebral neuroblastoma.

A desmoplastic primary cerebral neuroblastoma originating in the frontal lobe of a boy who died at the age of 6 years contained dense core vesicles within the cytoplasm of neoplastic cells as evidence of neuronal differentiation. Sarcomatous transformation had occurred at the time of recurrence. At autopsy, he also had cerebrospinal and extraneural metastases.

Autopsy↗
PubMed1992

Epidemiology and prevention of respiratory tract infections due to nonencapsulated Haemophilus influenzae.

Nonencapsulated Haemophilus influenzae cause mainly respiratory tract infections, including otitis, sinusitis, and pneumonia. These infections may become chronic or recurrent in patients with bronchitis or otitis. Patients are usually infected with one strain at a time. During recurrent otitis, H. influenzae isolates have an outer membrane protein composition different from that seen during earlier episodes. In chronic bronchitis, H. influenzae strains persist for up to 1 year. In addition, isolates with different outer membrane protein compositions have been obtained that are antigenic variants of previous isolates. The variations occur in outer membrane protein b,c (P2), d (P5), or both. The variable parts are immunodominant, and antibodies to these parts are bactericidal. Cross-reactive bactericidal antibodies to outer membrane proteins have been elicited in immunized animals. These data indicate that natural immunity to nonencapsulated H. influenzae is mainly strain-specific but also that biologically active cross-reactive antibodies can be elicited by immunization.

Antibodies, Bacterial↗
PubMed1999

Telomeric lengths and telomerase activity in liposarcomas.

To assess the role of telomerase in the development of liposarcomas, we measured telomerase activity in 36 malignant and seven benign lipomatous neoplasias from 34 patients. A sensitive polymerase chain reaction-based telomerase assay (the telomeric repeat amplification protocol) was applied. Shortening or elongation of telomeric repeat fragment lengths, as measured by using hybridization with a telomere-specific oligonucleotide probe, was correlated with the presence of telomerase activity. The latter was demonstrable in 69% of malignant tumors. Benign tumors can be distinguished from malignant neoplasias on the basis of telomerase activity. However, telomerase expression seems to be characteristic of poorly differentiated liposarcomas. Myxoid/round cell liposarcomas exhibited a higher telomerase activity level than the classical low-grade variants. Telomerase activity was not correlated with age at the time of diagnosis or with sex. In most cases, telomerase-positive tumors showed higher proliferation indices than did neoplasias lacking telomerase. All eight recurrences expressed telomerase activity, reflecting a close association of telomerase with the biological behavior of liposarcomas. Our findings suggest that telomerase may play a key role in the establishment and progression of malignant lipomatous tumors.

Adult↗
PubMed2004

Möbius sequence, Robin complex, and hypotonia: severe expression of brainstem disruption spectrum versus Carey-Fineman-Ziter syndrome.

We report on nine unrelated children fitting a diagnosis of Carey-Fineman-Ziter syndrome (CFZS). All children presented with Möbius sequence, Pierre Robin complex (6/9) or micrognathia, and hypotonia. Some had primary hypoventilation, delayed development, and acral anomalies. The neuropathological investigations performed in two patients showed a combination of dysplastic lesions (neuronal heterotopias) and encephaloclastic changes consisting of small foci of necrosis with microcalcifications. The mother of a third child had severe trauma during her 2nd month of pregnancy. Based on a review of the literature on MS and CFZS, we suggest designating as "Robin-Möbius phenotype" a distinct clinical variant of MS with extensive brainstem involvement, Robin complex, hypotonia without specific muscle disorder, clubfeet and variable acral anomalies. This condition appears to bear a higher risk of mental handicap and perhaps a higher recurrence risk than "common" MS. Neuropathology and neuroimaging are suggestive, at least in some cases, of a vascular disruption, which could be exogenous, or secondary to a genetic predisposition. Etiologic heterogeneity seems likely and, in that respect, the original CFZS family could represent a private syndrome fitting on the "Robin-Möbius" spectrum. Despite the existence of two familial reports, recurrence risk is probably much lower than 25%, although exact figures cannot be extracted from the available literature.

Abnormalities, Multiple↗
PubMed2000

A conserved "hydrophobic staple motif" plays a crucial role in the refolding of human glutathione transferase P1-1.

The specific (i, i+5) hydrophobic staple interaction involving a helix residue and a second residue located in the turn preceding the helix is a recurrent motif at the N terminus of alpha-helices. This motif is strictly conserved in the core of all soluble glutathione transferases (GSTs) as well as in other protein structures. Human GSTP1-1 variants mutated in amino acid Ile(149) and Tyr(154) of the hydrophobic staple motif of the alpha6-helix were analyzed. In particular, a double mutant cycle analysis has been performed to evaluate the role of the hydrophobic staple motif in the refolding process. The results show that this local interaction, by restricting the number of conformations of the alpha6-helix relative to the alpha1-helix, favors the formation of essential interdomain interactions and thereby accelerates the folding process. Thus, for the first time it is shown that the hydrophobic staple interaction has a role in the folding process of an intact protein. In P(i) class GSTs, Tyr(154) appears to be of particular structural importance, since it interacts with conserved residues Leu(21), Asp(24), and Gln(25) of the adjacent alpha1-helix which contributes to the active site. Human GSTP1-1 variants L21A and Y154F have also been analyzed in order to distinguish the role of interdomain interactions from that of the hydrophobic staple. The experimental results reported here suggest that the strict conservation of the hydrophobic staple motif reflects an evolutionary pressure for proteins to fold rapidly.

Amino Acid Sequence↗
PubMed1998

Characterization of ancestral and derived Y-chromosome haplotypes of New World native populations.

We analyze the allelic polymorphisms in seven Y-specific microsatellite loci and a Y-specific alphoid system with 27 variants (alphah I-XXVII), in a total of 89 Y chromosomes carrying the DYS199T allele and belonging to populations representing Amerindian and Na-Dene linguistic groups. Since there are no indications of recurrence for the DYS199C-->T transition, it is assumed that all DYS199T haplotypes derive from a single individual in whom the C-->T mutation occurred for the first time. We identified both the ancestral founder haplotype, 0A, of the DYS199T lineage and seven derived haplogroups diverging from the ancestral one by one to seven mutational steps. The 0A haplotype (5.7% of Native American chromosomes) had the following constitution: DYS199T, alphah II, DYS19/13, DYS389a/10, DYS389b/27, DYS390/24, DYS391/10, DYS392/14, and DYS393/13 (microsatellite alleles are indicated as number of repeats). We analyzed the Y-specific microsatellite mutation rate in 1,743 father-son transmissions, and we pooled our data with data in the literature, to obtain an average mutation rate of.0012. We estimated that the 0A haplotype has an average age of 22,770 years (minimum 13,500 years, maximum 58,700 years). Since the DYS199T allele is found with high frequency in Native American chromosomes, we propose that 0A is one of the most prevalent founder paternal lineages of New World aborigines.

Alleles↗
PubMed1980

Clear cell carcinoma of the skin. A variant of the squamous cell carcinoma that simulates sebaceous carcinoma.

Certain clear-cell carcinomas of the skin observed in elderly caucasian men with a history of excessive sun exposure and multiple skin neoplasms may be mistaken for sebaceous carcinomas or other cutaneous clear-cell tumors. These tumors are believed to be variants of squamous cell carcinoma undergoing extensive hydropic change which results in the clear-cell appearance. They are classified into three histologic types. Type I and type III tumors are either primary or recurrent squamous-cell carcinomas. The histogenesis of type II tumors is uncertain but they may represent recurrent metastatic tumors from the previously excised, adjacent epidermal squamous-cell carcinomas; however, the possibility that they are primary adnexal tumors of undetermined histogenesis remains to be determined. Various techniques of staining, as well as differences in histologic appearance, assist in the differential diagnosis of these and other cutaneous clear-cell neoplasms.

Adenocarcinoma↗
PubMed2003

Clear cell meningioma of the fourth ventricle.

Clear cell meningioma (CCM) has been identified and included in the World Health Organization classification of CNS tumors recently. CCMs are histologically characterized by sheets of polygonal cells with clear cytoplasm, which is the expression of high glycogen concentration. Compared with other variants of meningiomas, CCMs occur in younger patients and usually are located in the spinal canal and posterior fossa, the last ones mainly in the cerebellopontine angle. Some reports suggest that CCMs have high recurrence rate and potentially aggressive behavior. Poor outcome has been shown in intracranial and spinal tumor location, but indicators that predict outcome have not been established. The authors present two cases of intracranial CCMs, with excellent outcome in patients harboring tumor location (restricted to the fourth ventricle) and some clinical particular features (young age, gender, obesity, and moderate impairment of intellectual capacity). To the best of our knowledge, these are the two first reported cases of clear cell meningioma located primarily in the fourth ventricle.

Adult↗
PubMed2000

Treatment of posttransplant lymphoproliferative disorder with the anti-CD20 monoclonal antibody rituximab alone in an adult after liver transplantation: a new drug in therapy of patients with posttransplant lymphoproliferative disorder after solid organ transplantation?

BACKGROUND: Posttransplant lymphoproliferative (PT-LPD) disorder is a life-threatening complication with an incidence of 1-10%. Uniform treatment, so far, does not exist. METHODS: In December 1996, 5 months after a liver transplant, a 43-year-old patient developed a PT-LPD with para-aortal lymphomas and splenomegaly. Histological investigations revealed a PT-LPD of a diffuse large B-cell type of the centroblastic variant. The patient received three cycles of a modified cyclophosphamide, doxorubicin, vincristine, and prednisone-regimen, resulting in complete remission but the patient withdrew from further treatment. In February 1998, the patient had a recurrence of PT-LPD with gastric involvement and parasplenic lymphomas. The patient rejected cytotoxic treatment because of her fear of drug-induced progressive myopathy, so we conducted treatment with the monoclonal antibody--directed against CD20-rituximab. RESULTS AND CONCLUSIONS: After 2 doses of rituximab, clinical symptoms had disappeared and after 6 doses, gastroscopy revealed no residual disease. At this time, the patient remains in remission, with a follow up of > or =6 months. Anti-CD20 monoclonal antibody rituximab is a new, well-tolerated drug for the treatment of lymphomas. In addition, this drug may offer an additional treatment option for patients with PT-LPDs.

Adult↗
PubMed1999

Molecular diagnostics of epidermolysis bullosa: novel pathomechanisms and surprising genetics.

Tremendous progress has been recently made in understanding the molecular basis of epidermolysis bullosa (EB), and as of today specific mutations have been delineated in 10 distinct genes in different subtypes of this genodermatosis. Molecular diagnostics of EB has implications for improved classification with prognostic significance, refined genetic counseling, and establishment of DNA-based prenatal testing. During elucidation of mutations in different variants of EB, novel pathomechanisms, including uniparental isodisomy in junctional EB and de novo dominant mutations in dystrophic EB, have been encountered. These observations have relevance to counseling the families of the risk of recurrence of EB in subsequent pregnancies in the same and future generations.

Collagen↗
PubMed1992

Idiopathic hypercalciuria causing osteoporosis and hypocalcemia.

Idiopathic hypercalciuria, though a common cause of nephrolithiasis, has not been recognized to cause hypocalcemia and severe bone disease. We describe an adolescent with idiopathic hypercalciuria who presented initially with severe hypocalcemia and osteoporosis and this was later complicated by recurrent renal calculi formation after calcium and vitamin D supplement. After treatment with thiazide, hypercalciuria was controlled and serum biochemistry normalized. While idiopathic renal hypercalciuria may cause a negative calcium balance in adults, a variant of this syndrome with severe renal calcium leak occurring in a growing subject could lead to severe hypocalcemia and osteoporosis.

Adolescent↗
PubMed2004

Surgical treatment of coarctation of the aorta using trapezoidal aortoplasty.

OBJECTIVE: Trapezoidal aortoplasty is a technical variant of end-to-end anastomosis, which, based on elements of geometry, aims at increasing the diameter of the aorta at the level of the suture, therefore reducing the occurrence of residual or recurrent pressure gradients in the short and long run. METHODS: After resecting the coarcted area and ductal tissue, 3 trapezoids are confected in each aortic stump, which, when confronted, create a suture line with a sinusoidal aspect (zigzag). Thirty-three patients underwent surgery with this technique, 22 (66.7%) males, with ages ranging from 3 months to 36 years (mean of 9.84 +/- 9.69). RESULTS: No immediate or late deaths occurred. Follow-up ranged from 1.1 to 7.6 years (mean of 3.6 +/- 3.4). Most patients became asymptomatic with normal blood pressure levels, enabling the discontinuation of antihypertensive therapy (P<0.0001). A significant reduction in the pressure gradients was observed on Doppler echocardiography and during cardiac catheterization (P<0.001). The analysis of the images of aortography showed good anatomical continuity in the region of the anastomosis, and the morphometric study of the aorta revealed the beneficial effects of the technique indicated by the increase in the caliber of the aorta in the distal segment of the arch, isthmus, and descending portion. CONCLUSION: Trapezoidal aortoplasty showed satisfactory clinical results that allow its application in all cases indicated for end-to-end anastomosis.

Adolescent↗
PubMed1999

T-small lymphocyte disorders.

Less than 2% of all lymphoproliferative diseases are indolent or small T-cell disorders, and include T-cell chronic lymphocytic leukemia (CLL)/prolymphocytic leukemia (PLL), large granular lymphocyte (LGL) leukemia, and mycosis fungoides (MF). T-PLL has an aggressive clinical course characterized by high lymphocyte counts, marked hepatosplenomegaly, anemia, thrombocytopenia, and median survival times less than 1 year. The majority of cases are associated with abnormalities of chromosome 14. T-CLL probably represents a small cell variant of T-PLL with a similar aggressive course and similar cytogenetics. T-LGL leukemia is a clonal disorder of CD3+, cytotoxic T lymphocytes. Common clinical features include neutropenia, anemia, splenomegaly, and recurrent bacterial infections. The prognosis is dictated by the severity of the neutropenia, with 10-year actuarial survival rates greater than 80%, and most deaths related to sepsis. A small subset of LGL leukemias have a natural killer (NK) phenotype, are refractory to treatment, and result in multiorgan failure and death in a few months. Mycosis fungoides (MF), the most common of the small T-cell disorders, is a cutaneous T-cell lymphoma with a chronic course, often extending over decades, with most patients eventually succumbing to infection. The small T-lymphocyte disorders represent a rare, diverse group of diseases, which generally have an indolent course, but are not curable.

Chromosome Aberrations↗
PubMed2001

Myxoid leiomyosarcoma of the left atrium: a rare malignancy of the heart and its comparison with atrial myxoma.

Primary tumours of the heart are rare. The majority of these tumours are benign, with myxomas located in the left atrium being the most common form. Almost all malignant tumours are sarcomas and occur preferentially in the right side of the heart. An exception to this rule is leiomyosarcoma, a rare form of primary cardiac sarcoma that occurs predominantly in the left atrium, as does cardiac myxoma. The case of a 53-year-old woman who presented with symptoms of mitral valve stenosis and pulmonary hypertension is reported. Cardiac catheterization, angiography and echocardiography revealed a left atrial mass that was interpreted as atrial myxoma. At the time of operation, the myxoid appearance of the tumour mass further supported this assumption. The tumour, including a wide rim of atrial septum, was removed with cautery. Histopathological examination unexpectedly showed that the tumour was not an atrial myxoma but rather a myxoid variant of a primary leiomyosarcoma. Immunohistochemistry and electron microscopy confirmed the diagnosis. Local radiotherapy was considered but deemed contraindicated in view of the longstanding pulmonary hypertension. Two months after excision, a repeat echocardiogram indicated recurrence of tumour in the left atrium, and the patient died a few days later. The preferential left atrial location and the frequently myxoid appearance of primary leiomyosarcomas of the heart make it particularly difficult to differentiate them preoperatively from atrial myxomas. The authors recommend resection of all atrial myxoid tumours with a wide (at least 1 cm) margin, combined with intraoperative frozen section diagnosis, because complete surgical resection appears to correlate with prolonged survival in the few reported cases of atrial leiomyosarcomas. In cases of incomplete initial resection or local recurrence in the absence of metastatic disease, heart transplantation may be a valid option in appropriately selected patients.

Cardiac Catheterization↗