Metabolic enhancers supporting 1-carbon cycle affect sperm functionality: an in vitro comparative study.

The sperm plasma membrane is a sensitive target to oxidative stress. The most representative reactive oxygen species (ROS) scavengers in the genital tract, hypotaurine and glutathione, require, for their synthesis, cysteine whose availability is associated with the 1-carbon cycle (1-CC). Human, bovine and ascidian spermatozoa were incubated with compounds supporting the 1-CC (Vitamin B6, Methylcobalamin, 5 Methyl Tetrahydrofolate, Zinc Bisglycinate and N-acetyl-cysteine) (TRT) and compared to the effects induced solely by N-acetyl-cysteine (NAC). In control groups (CNTRL), spermatozoa were incubated with medium alone. After 90 and 180 minutes of incubation, the mitochondrial membrane potential (ΔΨM) in TRT and NAC was significantly (P < 0.01) higher than in CNTRL. At H2DCFDA evaluation, ROS production differed between species whereas, at 2-OH Ethidium, it significantly decreased in bovine TRT group. Intracellular pH (pHi) did not significantly vary in relation to treatment. In ascidian spermatozoa, the NAC supplementation decreased external pH, which in turn brought to a pHi lowering. Buffering seawater with NaHCO3 reversed the beneficial effects of N-acetyl-cysteine supplementation. In conclusion, both fully supporting the 1-CC and treatment with N-acetyl-cysteine alone improved kinetics, ΔΨM and ROS production in mammalian sperm demonstrating for the first time the direct in vitro effects of these compounds on sperm functionality.

New approaches for imaging and therapy of solid cancer.

Radionuclide therapy is a systemic treatment that aims to deliver cytotoxic radiation to cancer cells. Due to their properties, antibodies have been considered as suitable agent for the delivery of therapeutic radioisotopes, radioimmunotherapy (RIT). This article gives an overview of new approaches for imaging and therapy of solid cancer with particular attention to strategies to enhance treatment success. Examples of increased antibody uptake by targeting stromal constituent of tumor microenvironment such as fibronectin (FN) an important tumor-associated angiogenesis targeting agent, with specifically designed antibody format will be provided. Strategies oriented to identify patients most likely to benefit from RIT including identification of radiosensitivity profiles, in vivo target identification by teragnostic approach and better prediction of dosimetric estimates would be presents. Combination regimens such as with chemo-radiotherapy and immunotherapy would be also discussed as an approach to enhance RIT success.

Meiosis progression and donor age affect expression profile of DNA repair genes in bovine oocytes.

Several genetic and physiological factors increase the risk of DNA damage in mammalian oocytes. Two critical events are: (i) meiosis progression, from maturation to fertilization, due to extensive chromatin remodelling during genome decondensation; and (ii) aging, which is associated with a progressive oxidative stress. In this work, we studied the transcriptional patterns of three genes, RAD51, APEX-1 and MLH1, involved in DNA repair mechanisms. The analyses were performed by real-time quantitative PCR (RT-qPCR) in immature and in vitro matured oocytes collected from 17 ± 3-month-old heifers and 94 ± 20-month-old cows. Batches of 30-50 oocytes for each group (three replicates) were collected from ovarian follicles of slaughtered animals. The oocytes were freed from cumulus cells at the time of follicle removal, or after in vitro maturation (IVM) carried out in M199 supplemented with 10% fetal calf serum, 10 IU luteinising hormone (LH)/ml, 0.1 IU follicle-stimulating hormone (FSH)/ml and 1 µg 17ß-oestradiol/ml. Total RNA was extracted by Trizol method. The expression of bovine GAPDH gene was used as the internal standard, while primers for bovine RAD51, APEX-1 and MLH1 genes were designed from DNA sequences retrieved from GenBank. Results obtained indicate a clear up-regulation of RAD51, APEX-1 and MLH1 genes after IVM, ranging between two- and four-fold compared with germinal vesicle (GV) oocytes. However, only RAD51 showed a significant transcript increase between the immature oocytes collected from young or old individuals. This finding highlights RAD51 as a candidate gene marker for discriminating bovine immature oocytes in relation to the donor age.

Radiolabelled leucocyte scintigraphy versus conventional radiological imaging for the management of late, low-grade vascular prosthesis infections.

PURPOSE: In this study we evaluated the diagnostic performance of (99m)Tc-HMPAO-leucocyte ((99m)Tc-HMPAO-WBC) scintigraphy in a consecutive series of 55 patients (46 men and 9 women, mean age 71 ± 9 years, range 50 - 88 years) with a suspected late or a low-grade late vascular prosthesis infection (VPI), also comparing the diagnostic accuracy of WBC with that of other radiological imaging methods. METHODS: All patients suspected of having VPI underwent clinical examination, blood tests, microbiology, US and CT, and were classified according to the Fitzgerald criteria. A final diagnosis of VPI was established in 47 of the 55 patients, with microbiological confirmation after surgical removal of the prosthesis in 36 of the 47. In the 11 patients with major contraindications to surgery, the final diagnosis was based on microbiology and clinical follow-up of at least 18 months. RESULTS: (99m)Tc-HMPAO-WBC planar, SPECT and SPECT/CT imaging identified VPI in 43 of 47 patients (20 of these also showed infection at extra-prosthetic sites). In the remaining eight patients without VPI, different sites of infections were found. The use of SPECT/CT images led to a significant reduction in the number of false-positive findings in 37% of patients (sensitivity and specificity 100 %, versus 85.1% and 62.5% for stand-alone SPECT). Sensitivity and specificity were 34% and 75% for US, 48.9% and 83.3% for CT, and 68.1% and 62.5% for the FitzGerald classification. Perioperative mortality was 5.5%, mid-term mortality 12%, and long-term mortality 27%. Survival rates were similar in patients treated with surgery and antimicrobial therapy compared to patients treated with antimicrobial therapy alone (61% versus 63%, respectively), while infection eradication at 12 months was significantly higher following surgery (83.3% versus 45.5%). CONCLUSION: (99m)Tc-HMPAO-WBC SPECT/CT is useful for detecting, localizing and defining the extent of graft infection in patients with late and low-grade late VPI with inconclusive radiological findings. (99m)Tc-HMPAO-WBC SPECT/CT might be used to optimize patient management.

Ca2+ signaling during maturation of cumulus-oocyte complex in mammals.

Under the influence of gonadotropins or growth factors, a close cooperation develops between cumulus cells and the oocyte that is implicated in transmitting signals involved in maintaining or releasing the meiotic arrest in the oocyte. While cyclic adenosine 5'-monophosphate (cAMP) is a key molecule in maintaining the meiotic arrest, calcium (Ca(2+)) may play a role in controlling either spontaneous or gonadotropin-induced oocyte maturation, possibly by modulating intracytoplasmic cAMP concentrations via Ca(2+)-sensitive adenylate cyclases. This review focuses on the mechanisms related to the origin of the Ca(2+) wave that travels from the cumulus cells to the oocyte, and discusses the source of variations affecting the dynamics of this wave.

Nuclear factor-kappa-B-inhibitor alpha (NFKBIA) is a developmental marker of NF-κB/p65 activation during in vitro oocyte maturation and early embryogenesis.

BACKGROUND: The oocyte-to-embryo transition (OET) requires a co-ordinated transcriptional programme acting through evolutionarily conserved events, and transcription factors (TFs) are known to control these processes. Here, we focus on nuclear factor (NF)-κB, a TF involved in several cellular processes, studying NFκB-inhibitor (NFKBIA) mRNA and its protein product, IκBα, during OET. NFKBIA and IκBα are part of a regulatory loop, as IκBα is the major down-regulator of NF-κB activation while NFKBIA transcription is activated by NF-κB. METHODS AND RESULTS: We found a dynamic correlation between NFKBIA transcript, expression of IκBα-protein and activation of NF-κB/p65 in bovine oocyte and embryo. During the transition from immature to in vitro matured bovine oocyte, we observed a decrease in maternal NFKBIA mRNA and a parallel increase of the IκBα-protein (both P < 0.05). In the embryo, NFKBIA neo-synthesis is activated as a consequence of embryo genome activation (EGA), and IκBα decreases. NF-κB/p65-binding activity was detectable at low levels in immature oocyte, disappeared in dormant metaphase II oocyte and was strong in the embryo, during embryonic NFKBIA synthesis. The level of NF-κB/p65 DNA binding correlates with the timing of meiotic silencing during bovine oocyte maturation and embryonic transcription reprogramming. CONCLUSIONS: The IκBα/NF-κB circuit appears to be a tightly stage-controlled mechanism that could govern OET, being activated at EGA. Our findings represent the first characterization of NFKBIA and IκBα as maternal effectors in both the bovine oocyte and embryo. We suggest a role for NFKBIA as a marker of NF-κB/p65 activation in the human oocyte and early embryo.

Model for end-stage liver disease: impact of the new deceased donor liver allocation policy in São Paulo, Brazil.

Since 1997, organ transplantation in Brazil has been regulated by a federal law, which was created to guarantee equal access to treatment on a national scale. Centralized deceased donor organ procurement and sharing are controlled by the Health Department of each state of the nation, following a regional allocation policy. In São Paulo, time on the waiting list was the main criterion adopted to allocate deceased donor livers up to July 15, 2006. After that, model for end-stage liver disease/pediatric end-stage liver disease (MELD/PELD) scores were the main criteria. The aim of this study was to investigate the impact of the new criteria on patient survival rates using 895 consecutive liver recipients. The 1-year patient survival rates were compared between recipients transplanted based on the waiting time policy and based on MELD/PELD scores showing similar results (69.79% vs 66.69%; P = NS). Regarding liver allocation based on MELD/PELD scores, worse survival outcomes were observed among recipients transplanted with higher MELD scores. Also, under the new criteria, a high frequency of hepatocellular carcinoma and pediatric recipients underwent transplantation.

Choroid plexus cysts and their anatomical correlations: importance in fetal prognosis. A critical literature review

The objective of this investigation was to carry out a literature review on the choroid plexus cysts and theirimportance in fetal prognosis with search on PubMed, Web of Science, LILACS and MEDLINE databases usingkeywords in English without time restrictions. Choroid plexus cysts, which are also termed intraventricularneuroepithelial cysts, choroid epithelial cysts or ependimary cysts, are structures localized within the interiorof the lateral ventricles, comprising secretory epithelium, the principal function of which is the production ofcerebrospinal fluid. Ultrasound images of the choroid plexuses within the lateral ventricles consist of hyperechogenicstructures at the level of the body, trigon and inferior horn of the ventricles. Between the 16th andthe 20th week of gestation, cystic structures in the interior of the ventricular plexuses may be observed at arate of 0.3-1.0% in an ultrasound examination of the fetal head, as is shown. Most choroid plexus cysts regressspontaneously without after effects, although there is a possible association with chromosomal abnormalities,notably trisomy 18 (Edwards’ syndrome) and less frequently cited, trisomy 21 (Down syndrome). The presenceof this kind of cyst is considered to be a lesser marker for them, except when combined with other morefrequently used and accepted ecographic markers, such as nuchal translucency, intracardiac echogenic focusand others. Its isolated presence as the sole characteristic of this aneuploidy is rare. The majority of choroidcysts are transitory and of little clinical significance, and may be identified through a computerized tomographyexamination. As such, the existence of isolated choroid cysts does not indicate the confirmation of chromosomalaneuploidies so much as an alarm that should trigger an investigation in greater depth in search ofother more important markers, emphasizing the importance of pre-natal monitoring.

[Safety of tumescent liposuction]. / Hohe Sicherheit der Tumeszenz-Liposuktion.

Liposuction surgery is increasing in frequency and is the most commonly performed cosmetic procedure to date. Regularly, complications and fatalities are reported by tabloids. The anaesthesiogical techniques used, however, are usually not reported. Tumescent liposuction has to be clearly separated from liposuction with intravenous sedation or under general anaesthesia. In tumescent liposuction, tumescent fluid containing saline, lidocaine and adrenaline is injected into the undesired fat deposits and the pain is controlled locally. In contrast, when liposuctions are performed either with intravenous sedation or under general anaesthesia, the patient is unconscious. In this study, the different anaesthesiological techniques currently used for liposuction were compared with each other. Reported fatalities were reviewed and it was determined, whether liposuction was performed as tumescent liposuction or if systemic sedation was used. To date, no fatalities were reported when tumescent liposuction was performed and a total of 396 457 liposuctions (including own unpublished data) was counted. Fatalities, however, were reported, when either intravenous sedation or general anaesthesia was performed, and a mortality rate of 2.6-19.1 per 100000 cases was counted. Liposuctions should therefore, whenever possible be performed as tumescent liposuction. Intravenous sedation or general anaesthesia should be more carefully considered.

Asymmetries of the Left and Right Temporal Lobes / Asimetría de los Lóbulos Temporales Izquierdo y Derecho

Anatomical brain asymmetries are subtle and still little studied in humans. Among all the animals, humans have the most asymmetric brains Crow (2004). The language faculty and handedness are localized on the left side. The objective this paper is to verify whether the temporal lobes are anatomically different. Our sample was composed of 40 post mortem adult brains of both sexes, which were investigated at the Human Anatomy Laboratory of the Nove de Julho University Center in Sao Paulo, Brazil. The brains were fixed in a solution of 5% paraformaldehyde. Three different measurements were taken using a pachimeter (Mitutoyo) and a goniometer (Card) on both hemispheres: Ml - the length of the lateral sulcus; M2 - the distance from the lateral sulcus to the inferior margin of the inferior temporal gyrus, and M3 - the angle formed between the lines of the collateral sulcus and the inferior margin of the inferior temporal gyrus. Results were submitted to a statistical analysis (ANOVA) and demonstrated that Ml was larger in the left hemisphere, by contrast with the data obtained for M2 and M3, which were larger in the right hemisphere. The measurements taken showed differences between the right and left temporal lobes.

Las asimetrías anatómicas del cerebro humano son sutiles y aún poco estudiadas. Entre todos los animales, el Hombre es el que presenta el cerebro más asimétrico (Crow, 2004). En el lado izquierdo del cerebro se localiza la facultad del lenguaje, como también de la lateralidad manual. El objetivo del trabajo fue verificar si los lóbulos temporales son anatómicamente diferentes. La muestra estuvo compuesta de 40 encéfalos adultos, post mortem, de ambos sexos, del Laboratorio de Anatomía del Centro Universitario Nove de Julho, en Sao Paulo, SP, Brasil. Los encéfalos fueron fijados en solución de formalina al 5%. Fueron realizadas 3 medidas diferentes utilizando un pié de metro Mitutoyo y goniómetro (Carci), en ambos hemisferios: medida MI, largo del surco lateral; medida M2 distancia del surco lateral hasta el margen inferior del giro temporal inferior y la medida M3 el ángulo formado entre las líneas del surco colateral y margen inferior del giro temporal inferior. Los resultados se sometieron a análisis estadístico y mostraron que MI era mayor en el hemisferio izquierdo, en contraposición a los datos obtenidos en M2 y M3, que fueron mayores en el hemisferio derecho. Las medidas realizadas presentaron diferencias entre los lóbulos temporales derecho e izquierdo.

D-aspartate and reproductive activity in sheep.

D-aspartic acid (D-Asp) has been isolated from neuroendocrine tissues of many invertebrates and vertebrates. Recently, it has been demonstrated that this D-amino acid may be converted to N-methyl-D-aspartic acid (NMDA), a neuromodulator associated with sexual activity. In this study, we determined D-Asp and NMDA concentrations in endocrine glands and other tissues in ewes after D-Asp administration and in controls. We also evaluated the effects of d-Asp administration on the reproductive activity of ewes by determining either progesterone concentrations or LH pulses in the presence or absence of estradiol benzoate. The pineal gland showed the highest natural content of D-Asp (1.47+/-0.22 micromol/g tissue), whereas the pituitary gland had the highest capability to store d-Asp, with a peak value (9.7+/-0.81 micromol/g tissue) 6 h after its administration. NMDA increased sharply 12 h following D-Asp administration, reaching values three times higher than the baseline in both the pituitary and brain. D-Asp was quickly adsorbed after subcutaneous administration, with a peak in plasma levels 2 h after administration and a return to baseline values after 6 h. D-Asp administration achieved a significant (P < 0.001) increase in LH values with respect to estradiol or estradiol + D-Asp treatments. d-Asp treatment once or twice a week did not successfully drive acyclic ewes into reproductive activity. In conclusion, the results obtained in this study demonstrated that D-Asp is endogenously present in sheep tissues and electively stored in endocrine glands and brain after its administration. NMDA and LH increase following D-Asp administration suggesting a role of this D-amino acid in the reproductive activity of sheep.

Histological, immunological and molecular features of a nasal mucosa primary melanoma associated with nasal melanosis.

Nasal mucosa melanoma is a rare entity that may occur together with nasal melanosis. The histological and immunological features and loss of heterozygosity analysis of such lesions have not been reported to date. In the study presented here short-term cell cultures were established from the patient's melanoma and subsequent relapses. Histology, immunohistochemistry, reverse transcription-polymerase chain reaction enzyme-linked immunosorbent assay, human leukocyte antigen analysis, microdissection with subsequent polymerase chain reaction for analysis of loss of heterozygosity were used to characterize the tumour and other cells. Melanoma of the nasal cavity was found, with a surrounding proliferation of atypical melanocytes corresponding to nasal melanosis. Immunoreactivity was found for S-100, gp100, tyrosinase and MelanA protein. Loss of heterozygosity for a p16-flanking marker was found in the tumour and the melanotic cells. Short-term cell cultures expressed tyrosinase and MUC18 at the mRNA level and intercellular adhesion molecule-1 (ICAM-1) and interleukin-12 receptor at the protein level. This is the first time short-term cell cultures have been established and analysed from such a tumour. Melanoma-associated antigens were identified within the tumour. The melanoma and the melanotic cells showed loss of heterozygosity for the p16 gene, which is implicated in melanoma development. This points to a common origin in tumorigenesis. Pathways of tumour escape, such as expression of CD54 and interleukin-10, were observed. The clinical, immunological and molecular features suggest that nasal melanosis should be followed closely.

Spitz nevi display allelic deletions.

BACKGROUND: Spitz nevi are acquired benign melanocytic lesions that occur in childhood and adolescence. Histologically, they resemble malignant melanoma and were first termed benign juvenile melanoma. Several studies have attempted the difficult task of establishing diagnostic criteria to differentiate between Spitz nevi and malignant melanoma. OBJECTIVE: To elucidate sets of diagnostic criteria for differentiation between the 2 lesions. DESIGN: We aimed to search for allelic deletions in Spitz nevi and to evaluate whether loss of heterozygosity (LOH) or microsatellite instability (MSI) would be a valuable diagnostic tool to differentiate between Spitz nevi and malignant melanoma. SETTING: Two areas within each of 5 lesions were microdissected, and LOH and MSI were evaluated at chromosomes 6q (using polymorphic DNA marker D6S305), 9p21 (D9S171, IFNA, D9S265, and D9S270), 10q (D10S185), and 14q (D14S53). PATIENTS: Five Swiss patients with Spitz nevi. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Allelic deletions may serve as a diagnostic tool to distinguish Spitz nevi from melanoma. RESULTS: All lesions were informative, displaying LOH or MSI with at least one marker. No LOHs were found at 14q. At 6q, MSI was found in 2 dissected areas from the same lesion; the remaining lesions were noninformative. Loss of heterozygosity was found in 2 of 6 areas at D9S171, 2 of 6 at IFNA, 3 of 6 at D9S270, 3 of 4 at D9S265, and 1 of 4 at D10S185. Microsatellite instability was found in 1 of 4 areas at D9S265. CONCLUSIONS: With the markers used in our study, Spitz nevi display LOH and MSI similar to those in melanoma. Analysis of LOH or MSI is therefore not a suitable diagnostic tool in distinguishing Spitz nevi from melanoma.

Heterogeneity of allelic deletions within melanoma metastases.

During the initiation and progression of malignant melanoma, a series of different genetic events accumulate on several different chromosomes. The biological heterogeneity of tumour cells presents a major problem, preventing effective treatment of melanoma. To examine the degree of genetic heterogeneity, we searched for allelic losses (loss of heterozygosity; LOH) on chromosomes 9p, 9q, 1p and 17p, examining different areas within human melanoma metastases. All of the examined metastases were informative within at least one dissected area for at least one marker. Out of 29 areas in 11 melanoma metastases, 58% showed LOH with at least one marker. On chromosome 9p21-22, eight out of 26 informative loci (31%) showed LOH at D9S171 (three not informative), two out of 18 (11%) at IFNA (11 not informative) and seven out of 24 (29%) at D9S169 (five not informative). LOH on chromosome 9q22.3 was examined by the microsatellite marker D9S12; three out of 24 areas (12.5%) showed LOH, and five were not informative. Deletions on chromosome 1p were assessed using D1S450. Four out of 25 (16%) showed LOH; four were not informative. Deletions on chromosome 17p13 were examined with TP53; two out of 21 cases (9%) showed LOH, and eight were not informative. Our data demonstrate an impressive heterogeneity of allelic losses in the investigated chromosomal areas within the same metastatic lesion. This suggests that there is not one specific genetic alteration that accounts for melanoma progression to metastases. Rather there seem to be multiple genetic alterations accumulating even on the same chromosome, and progression from melanoma to metastases is paralleled by the accumulation of clones harbouring multiple genetic abnormalities.

Syringocystadenoma papilliferum: a study of potential tumor suppressor genes.

Syringocystadenoma papilliferum (SP) is a benign tumor most commonly located on the scalp or face, which frequently arises from a nevus sebaceus (NS). Transition of SP to basal cell carcinoma (BCC) and, albeit rarely, to metastatic adenocarcinoma may occur. Allelic deletions of the human homologue of the drosophila patched gene (PTCH) occur in both NS and BCC. To search for genetic changes in SP, a microdissection-based genetic analysis using polymorphic markers at 9q22 (PTCH; D9S15, D9S303, D9S287, D9S252) as well as markers at 9p21 flanking the tumor suppressor gene p16 (IFNA, D9S171) was performed. Glandular epithelium consisting of two rows of cells as well as adjacent normal tissue or inflammatory infiltrates in the stroma, when present, was dissected and subjected to single-step DNA extraction and loss of heterozygosity (LOH) analysis. Two of 10 informative SP cases showed LOH at 9q22 (PTCH). Three of 7 informative SP cases showed allelic deletions at 9p21 (p16). Allelic loss at 9q22 is consistent with the clinical observation of transition of SP to BCC. The finding of frequent allelic loss at 9p21 is unlikely to be related to the rare transition of SP to metastatic adenocarcinoma. Our study supports the hypothesis of a gatekeeper role of the tumor suppressor gene p16 in a variety of benign and malignant tumors, including SP.

TAP1 down-regulation in primary melanoma lesions: an independent marker of poor prognosis.

Melanoma tumor thickness is a major prognostic factor. Thin lesions, however, may metastasize, and sometimes thick tumors may not. To investigate the role of HLA class I-mediated antigen presentation, we correlated the expression of components of the antigen-processing machinery in primary melanoma lesions with their thickness and with the development of metastases. Seventeen formalin-fixed, paraffin-embedded primary melanomas thinner than 0.76 mm and 21 thicker than 1.50 mm were stained with anti-LMP2, -LMP7, -TAP1, -TAP2, -HLA class I and -beta2-microglobulin monoclonal antibodies. Twenty patients remained tumor-free in the follow-up period (10.5 +/- 1.8 years). Eighteen patients relapsed within a median period of 15.0 months following tumor excision. Expression of all markers in the tested lesions was down-regulated, the frequency ranging from about 40% for LMP and TAP subunits to about 70% for HLA class I antigens. Expression of all markers was not correlated with tumor thickness. Only TAP1 and TAP2 down-regulation was significantly (p = 0.026 and 0.042, respectively) correlated with the development of metastases. This correlation was independent of tumor thickness for TAP1. We suggest that TAP1 and probably TAP2 expression in primary lesions represents an independent prognostic marker in melanoma. Abnormalities in antigen presentation may account for the lack of absolute correlation between tumor thickness and prognosis.

Allelic deletion at 9p21-22 in primary cutaneous CD30(+) large cell lymphoma.

The genetic alterations responsible for the development of cutaneous lymphoma are largely unknown. Chromosome region 9p21 contains a gene locus encoding an inhibitor of cyclin-dependent kinase 4, and heterozygous deletions of this tumor suppressor gene (p16) have been shown in a variety of malignant tumors. We studied 11 randomly selected cutaneous CD30-positive large cell lymphomas. Several areas containing 20-50 CD30-positive lymphocytes were microdissected in each case and subjected to single-step DNA extraction. Loss of heterozygosity analysis was performed using polymorphic markers at 9p21 (IFNA, D9S171, D9S169) and 17p13 (TP53). Samples from normal cells apart from CD30-positive lymphocytes, e.g., CD30-negative lymphohistiocytic infiltrates and normal epidermal layer, were also obtained in all cases from the same slide for comparison with the tumor samples. Expression of CD30 and T-lineage antigens (CD3, CD45Ro) was confirmed in all cases. Immunohistochemical staining for p16 and p53 was performed using the monoclonal antibodies sc-1661 and DO-7, respectively. Of the 11 informative cases, seven (64%) exhibited loss of heterozygosity at least for one marker at 9p21 (p16), whereas no allelic deletions were found for the polymorphic marker at 17p13 (p53). On immunohistochemistry loss of the p16 protein was detected in two of 11 cases. Nuclear staining for p53 protein was found in four of 11 cases. Here, we provide the first evidence of the involvement of the tumor suppressor gene p16 in primary cutaneous large cell lymphoma. Whether p16 deletion in these lymphomas is associated with disease progression and whether this method could serve as an early marker to detect lymphomas at an early stage needs to be addressed in future studies. J Invest Dermatol 115:1104-1107 2000