Mitochondrial Membrane Dynamics and Inherited Optic Neuropathies

Inherited optic neuropathies are a genetically diverse group of disorders mainly characterized by visual loss and optic atrophy. Since the first recognition of Leber's hereditary optic neuropathy, several genetic defects altering primary mitochondrial respiration have been proposed to contribute to the development of syndromic and non-syndromic optic neuropathies. Moreover, the genomics and imaging revolution in the past decade has increased diagnostic efficiency and accuracy, allowing recognition of a link between mitochondrial dynamics machinery and a broad range of inherited neurodegenerative diseases involving the optic nerve. Mutations of novel genes modifying mainly the balance between mitochondrial fusion and fission have been shown to lead to overlapping clinical phenotypes ranging from isolated optic atrophy to severe, sometimes lethal multisystem disorders, and are reviewed herein. Given the particular vulnerability of retinal ganglion cells to mitochondrial dysfunction, the accessibility of the eye as a part of the central nervous system and improvements in technical imaging concerning assessment of the retinal nerve fiber layer, optic nerve evaluation becomes critical - even in asymptomatic patients - for correct diagnosis, understanding and early treatment of these complex and enigmatic clinical entities.

Immunohistochemical Study of Vasculogenic Mimicry and Angiogenesis in Melanocytic Tumors of the Eye and the Periocular Area

BACKGROUND/AIM

The ability of a tumor to grow requires a sufficient blood supply. Microvascular density is considered the standard for assessing the neovasculature. Tumor cell vasculogenic mimicry refers to the formation of tumor cell-lined vessels that contribute to tumor neovascularization. The aim of the present work was to study angiogenesis and vasculogenic mimicry in benign and malignant melanocytic tumors of the eye and the periocular region.

PATIENTS AND METHODS

Histological sections from 118 patients were studied. Eighty-eight of the patients had nevi while the remaining 30 had malignant melanomas. Microvascular density was assessed by using antibodies against the endothelial cell markers CD31 and CD34. Vascular-like channels between neoplastic cells, that were not lined by endothelial cells and thus were negative for CD31 and CD34, represented areas of vasculogenic mimicry.

RESULTS

Angiogenesis was more pronounced in melanomas compared to melanocytic nevi and was increased in melanomas with high mitotic index and/or epithelioid cell preponderance compared to melanomas with low mitotic index and/or spindle cell predominance. Vasculogenic mimicry was observed in many melanomas, while it was evident in the minority of benign nevi as well.

CONCLUSION

The existence of vasculogenic mimicry in benign nevi might have prognostic implications.

Natural Compounds and Neuroprotection: Mechanisms of Action and Novel Delivery Systems

Neurodegeneration characterizes pathologic conditions, ranging from Alzheimer's disease to glaucoma, with devastating social and economic effects. It is a complex process implicating a series of molecular and cellular events, such as oxidative stress, mitochondrial dysfunction, protein misfolding, excitotoxicity and inflammation. Natural compounds, because of their broad spectrum of pharmacological and biological activities, could be possible candidates for the management of such multifactorial morbidities. However, their therapeutic potential against neurodegenerative diseases has been hampered by their poor bioavailability and subsequent insufficient delivery to the brain. This article provides an overview of the molecular mechanisms through which natural compounds exert their neuroprotective effects, as well as the development of novel natural compound-loaded delivery systems that could improve their neuroavailability.

The Spectrum of Infectious Diseases in Kidney Transplantation: A Review of the Classification, Pathogens and Clinical Manifestations

Kidney transplantation is the treatment-of-choice for a significant number of patients with end-stage renal disease. Renal transplant recipients (RTRs) benefit from a longer life expectancy, with a better quality of life. Despite, recent accomplishments in the field of kidney transplantation, both short- and long-term, surgical and medical complications still exist. Among these complications, cardiovascular disease, carcinogenesis and infections are the most important. Infectious diseases constitute the most common complications after renal transplantation and the second most common cause of death among RTRs with a functioning graft. Theoretically, all infectious pathogens could cause disease in immunocompromised RTRs, yet among these, one could identify more important ones, such as the Enterobacteriaceae, causing urinary tract infections; pneumonia due to Pneumocystis jirovecii; Candida species which cause invasive fungal infections; herpes viruses; hepatitis viruses and parasites. Early diagnosis and effective treatment are key elements in salvaging both the allograft and the patient. However, clinical manifestations and diagnosis of such infectious diseases are not easily identified due to the altered state of immune response of the RTR. Thus, apart from possessing a deep knowledge of the etiology and the treatment options in each case, transplant physicians should also always remain alert when dealing with RTRs.

Vasculogenic mimicry: lessons from melanocytic tumors

Tumor cell vasculogenic mimicry refers to the formation of tumor cell-lined vessels that contribute to tumor neovascularization and nutrient and oxygen supply. These tumor cells express many endothelial and stem cell markers, resulting in them having a unique phenotype. This phenomenon is observed in a variety of neoplasms, such as glioblastomas and sarcomas, as well as breast, ovarian, liver and lung carcinomas. It is also evident in melanocytic lesions, regardless of their benign or malignant nature. The biochemical and molecular events that regulate vasculogenic mimicry provide opportunities for development of novel forms of tumor-targeted treatments. Furthermore, the presence of this process in a tumor might have prognostic implications.

Relationships between body composition analysis measures in Greek women and US white women

We investigated the regional changes in body composition relative to age, in healthy Caucasian women living in the Mediterranean area. Body composition of total and subtotal body was measured, and fat mass (FM) ratios along with FM and lean mass (LM) indices were calculated in 330 women aged 20-85 years, using DXA. Data were compared with the NHANES reference database. Peak bone mineral density and bone mineral content of total body were 1.149 g/cm(2) and 2,209 g and were achieved between ages 41 and 50. Peak %FM of total body, FM index (FMI; FM/height(2)), FM of trunk to legs, and FM of trunk to limbs were 41.5%, 13.69 kg/m(2), 1.623, and 1.14, respectively. Peak %FM and FMI were achieved between 61 and 70 years. Unlike US counterparts, in our series, both FM ratios showed a propensity for women to accrue fat in the trunk following the android pattern of fat distribution. Peak LM index for total body (LMI; LM/height(2)) and limbs (ASMMI; appendicular skeletal muscle mass/height(2)) was 18.08 kg/m(2) and 7.33 kg/m(2), respectively, and was achieved between 61 and 70 years. For Greeks, the ASMMI was greater from 55 years onwards. Greek women have increasing bone mass in early adulthood followed by significant decline during fifties and onwards. Compared with US white women, Greek women have significantly greater truncal fat for all ages, implying a greater risk of obesity-associated diseases. Middle-aged and older Greek women have greater appendicular skeletal muscle mass, which may eliminate the overall risk of sarcopenic obesity.

Cytogenetic analysis of a low-grade secondary peripheral chondrosarcoma arising in synovial chondromatosis

Secondary chondrosarcoma is a malignant chondroid tumor arising in a benign precursor. Synovial chondromatosis is a benign chondroid lesion that rarely transforms to chondrosarcoma. We present the case of a 54-year-old male with the diagnosis of low-grade secondary peripheral chondrosarcoma developed in the context of synovial chondromatosis. Cytogenetics revealed a novel aberration t(1;14)(q23.1~24;q24.1~3). Multicolor banding (mBAND) analysis described the chromosomal regions involved in this translocation with a higher detail. Diagnosis of such borderline lesions is very difficult and cytogenetics is helpful in characterizing these tumors.

Real-Time PCR detection and quantitation of Helicobacter pylori clarithromycin-resistant strains in archival material and correlation with Sydney classification

BACKGROUND

Helicobacter pylori (H. pylori), infects gastric mucosa causing gastritis. Treatment failure is mainly due to certain genetic changes in the peptidyltransferase loop of 23S rRNA of the microorganism. The aim of the study was to evaluate genetic changes in gastric biopsies of H. pylori (+) patients that lead to clarithromycin resistance and to correlate them with histology data.

METHODS

A total of 150 H. pylori (+) gastric biopsies were studied, taken before and after eradication therapy from 75 dyspeptic patients divided in 2 groups: group A consisted of 25 H. pylori (+) triple-therapy resistant patients and group B consisted of 50 H. pylori (+) successfully treated patients. Histological classification of the H. pylori (+) gastritis was done according to the Sydney criteria. Genetic material was analyzed with the ClariRes™ RT-PCR bi-probe based assay for the determination of point mutations in the 23S rRNA gene and with a Quantitative-RT-PCR (Q-RT-PCR) method for the quantitation of H. pylori.

RESULTS

We showed that in 18/ 25 group A patients certain point mutations of 23S rRNA at sites A2142C, A2142G and A2143G had occurred. Nine of these 18 mutated cases (50%) were characterized as mixed infections. Mixed infections in 2/50 patients of group B were also observed. Using Q-RT-PCR, we found that gastric mucosal density of H. pylori correlates well with bacterial colonization. There was a statistically significant association (P<0.005) between the presence of the detected H. pylori genetic alterations and inflammation, activity and H. pylori density as histologically determined.

CONCLUSION

Certain point mutations in H. pylori genome that affect susceptibility to clarithromycin correlate with histological features of gastritis.

Mutational activation of k-ras oncogene in human breast-tumors

ras genes are thought to play an important role in human cancer since they have been found to be activated frequently in several types of human tumors. From preliminary studies it has been found however, that ras mutations are extremely rare in breast tumors and therefore it was of interest to examine the frequency of such mutations. In this study we examined 65 cases of primary breast carcinomas from paraffin blocks, for the presence of point mutations in codons 12 of the K-ras and H-ras genes. The polymerase chain reaction (PCR) technique was used to amplify a codon 12 containing 157 bp and a 312 bp region of the K-ras and the H-ras genes respectively, followed by restriction fragment length polymorphism (RFLP) analysis to identify the point mutations. Eight out of the 65 tumors (12.3%) were found to carry a K-ras mutation in codon 12 but none was found to carry a H-ras mutation. It is suggested that the mutational activation of the K-ras gene may be involved in the development of a small percentage of breast tumors.

[Colorectal carcinogenesis]

Colorectal adenocarcinomas were long thought to be an homogeneous entity, in which traditional adenomas of the colon were the best-recognized and most common precursor lesions. Current morphological and molecular data suggest an alternative pathway of colorectal carcinogenesis involving "serrated neoplasia". This pathway seems to be responsible for approximately 10% to 15% of sporadic colorectal adenocarcinomas. These serrated lesions, that may progress to cancer, show relatively distinct histopathological molecular and epigenetic features not commonly seen in traditional adenomas. Key characteristics of the serrated neoplasia pathway include BRAF gene mutations, excess CpG island methylation, and subsequent microsatellite instability. A major challenge for pathologists is to identify these new potential precursor lesions, in order to enable early diagnosis and treatment.

Serum and tissue selenium levels in gastric cancer patients and correlation with CEA

BACKGROUND

An inverse relationship between selenium (Se) intake and cancer mortality is evident in humans.

MATERIALS AND METHODS

In eighty patients who had been operated on for primary gastric cancer, serum Se and carcinoembryonic antigen (CEA) levels were measured preoperatively using a fluorometric and immunoradiometric assay (IRMA), respectively.

RESULTS

The serum Se levels were 43+/-6.3 microg l(-1) in the patient group and 68.7+/-4.5 microg l(-1) in healthy individuals (p<0.001). The serum CEA was 12+/-1.9 U ml(-1) in the gastric cancer patients and 2.1 U ml(-1) in the control group (p<0.001). The Se tissue concentrations were 2,640+/-220 mg g(-1) in excised neoplastic tissue and 685+/-115 mg g(-1) in non-neoplastic tissue (p<0.001). An inverse correlation between Se and CEA serum levels was found (r=-0.782). There was no correlation between serum/tissue Se concentration and disease stage/histological type or gender in the patient group.

Alterations of the p53, Rb and p27 tumor suppressor pathways in diffuse large B-cell lymphomas

Diffuse large B-cell lymphomas (DLBCL) display defects in cell cycle and apoptosis regulation. Therefore, the immunohistochemical expression patterns of the proteins p14, p21, Hdm2 and cyclin D2 were analyzed in relation to the previously reported expression of other major cell cycle proteins (p53, Rb, p16, p27, Ki-67 and cyclins A, B1, D2, D3 and E), apoptosis-associated proteins (bcl2, bcl-xl, bax, bak, bad and bid) and the B-cell differentiation immunophenotypes. Expression of the proteins p14, p21, Hdm2 and cyclin D2 was observed in 62/71 (87%), 22/76 (29%), 35/74 (47%) and 11/77 (14%) cases, respectively. Immunohistochemical alterations of the p53 (p53-Hdm2-p21-p14), Rb (Rb-p16-cyclin D [D2 or D3]) and p27 (p27-cyclin E) pathways were found in 56/77 (73%), 53/79 (67%) and 54/79 (68%) cases, respectively. Concomitant alterations of the p53-Rb, p53-p27 and Rb-p27 pathways were found in 40/77 (52%), 38/77 (50%) and 36/79 (46%) cases, respectively. Three concomitant alterations of the p53-Rb-p27 pathways were found in 28/79 (35%) cases. The main findings of the present study were the following: alterations of the p27 pathway were associated with higher expression of Ki-67 (p = 0.023); concomitant alterations of the p53Rb pathways and the p53-p27 pathways were associated with higher expression of cyclin A (p = 0.015 and p = 0.021, respectively) and concomitant alterations of the p53, Rb and p27 pathways were associated with higher expression of cyclin A (p = 0.013). Since cyclin A supports DNA replication, centrosome duplication and mitosis, these findings indicate that concomitant alterations of the p53, Rb and p27 pathways in DLBCL may have cooperative effects resulting in increased neoplastic cell proliferation. This might explain, at least partially, the association between concurrent aberrations of the p53, Rb and p27 pathways and aggressive clinical behavior in DLBCL.

Prognostic significance of HER-2, p53 and Bcl-2 in patients with epithelial ovarian cancer

BACKGROUND

Several oncogenes and onco-suppressor genes have been implicated in epithelial ovarian carcinogenesis, but their clinical significance is not clear and conflicting data have been found in various studies.

PATIENTS AND METHODS

The immunohistochemical expression of HER-2, p53 and Bcl-2 proteins was investigated in a cohort of 95 patients with advanced epithelial ovarian cancer (stages IIc-IV). These patients participated in a phase III randomized clinical trial and were treated either with paclitaxel/carboplatin, orpaclitaxel/carboplatin alternating with paclitaxel/cisplatin.

RESULTS

Positive immunostaining for HER-2, p53 and Bcl-2 proteins was found in 18%, 70.5% and 69.5% of the cases, respectively. In multivariate analysis, older patients (< 63 vs. > or = 63 years, p < 0.001), worse grade (I-II vs. III, p = 0.04) and p53 expression (negative vs. positive, p = 0.002) were significant prognostic factors independently associated with survival.

CONCLUSION

p53 status along with age and grade appear to be independent prognostic factors for survival in patients with epithelial ovarian cancer.

Chromosome analysis and molecular cytogenetic investigations of an epithelioid hemangioendothelioma

Epithelioid hemangioendothelioma is a rare, well-differentiated endothelial tumor with a wide spectrum of clinical behavior and for which genetic data are extremely limited. We present a case of an epithelioid hemangioendothelioma in a 22-year-old male, which was analyzed with multiple cytogenetic approaches. Conventional cytogenetic analysis detected structural abnormalities of 11q13 and 11q14, rings, and marker chromosomes. Multi-color FISH (mFISH) and high-resolution multi-color banding (mBAND) analyses demonstrated that the aberrations of chromosome 11 were deletions and that the ring and marker chromosomes consisted of 12(q14 approximately q21) material. Comparative genomic hybridization (CGH) analysis revealed gains of 11(q13 approximately q14) and 12(q11 approximately q21), loss of 11(q21 approximately qter), and 2 amplicons at 12(q12 approximately q13) and 12(q14 approximately q21). Our data indicate that a subset of epithelioid hemangioendotheliomas may be characterized by complex rearrangements involving deletions and gains of 11q and 12q amplifications. The present case also shows that, in order to describe and understand such complex chromosome aberrations, chromosome analysis must be complemented with several molecular cytogenetic techniques.

Rectal Epstein-Barr virus-positive Hodgkin's lymphoma in a patient with Crohn's disease: case report and review of the literature

We present the case of a 35-year-old man with Crohn's disease diagnosed at the age of 27, several months after an operation for small-bowel adenocarcinoma. Seven years after the adenocarcinoma diagnosis, the patient presented with severe continuous anal pain and diarrhea. In parallel with antibiotic administration, the patient was given treatment with Infliximab, but without clinical symptom amelioration. Sigmoidoscopy and subsequent biopsies from an ulcerated rectal area supported the diagnosis of Epstein-Barr virus-positive (EBV+) primary Hodgkin's lymphoma. Infliximab administration was immediately discontinued and the patient underwent oncological follow-up and began a course of chemotherapy. Only a few cases with primary gastrointestinal Hodgkin's lymphoma in Crohn's disease patients have so far been reported, including a variety of scenarios on the causal relationship including disease duration, presence of EBV, long-term immunosuppressive treatment and, recently, anti-TNFalpha administration.

Fos- and Jun-related transcription factors are involved in the signal transduction pathway of mechanical loading in condylar chondrocytes

The chondrocytes of the articular condylar cartilage proliferate, hypertrophy and ultimately undergo apoptosis (programmed cell death), being replaced by osteoblasts. Converging results consolidate activator protein-1 (AP-1) transcription factor as the pivotal downstream effector in the early response of stress-sensitive cells to mechanical loading, and the Fra-1, Fra-2, JunB and JunD members of the AP-1 transcription factor family, as mediators in bone remodelling and apoptotic phenomena. The aim of the present study was to examine the involvement of the Fra-1, Fra-2, JunB and JunD proteins in the biochemical response of functionally loaded mandibular condylar cartilage, and the subsequent initiation of cartilage maturation and apoptotic phenomena. Thirty, female, 14-day-old Wistar rats were assigned to two groups: one group was fed a soft diet and the other a hard diet. At day 21 after weaning, experimental animals from both groups were killed at 6, 12 and 48 hours and their condyles harvested. The condylar cartilage of both groups was immunostained using specific antibodies against Fra-1, Fra-2, JunB and JunD. Statistical analysis of the data revealed over-expression of Fra-1, Fra-2, JunB and JunD proteins in all stages of differentiation of chondrocytes derived from the mandibular condylar cartilage of animals fed on a hard diet. Moreover, the involvement of these proteins significantly increased with time in both groups. Since the aforementioned proteins play key roles in remodelling phenomena of bone and cartilage tissue, influencing pivotal cellular functions such as maturation, differentiation and apoptosis, the results of the present study suggest that mandibular condylar chondrocytes sense functional loading changes and respond by induction of proteins associated with biological phenomena that ultimately influence the growth of the condylar cartilage.

Inflammatory bowel disease-related dysplasia and cancer: A referral center study in northwestern Greece

BACKGROUND: An increased risk of colorectal cancer in ulcerative colitis (UC) and Crohn's disease (CD) has been reported. No data on inflammatory bowel disease (IBD)-related dysplasia and cancer is available in Greece, where the disease profile seems to be milder than that of northern Europe. METHODS: A study was conducted of 215 IBD patients (182 with UC, 33 with CD) from a referral center. Patients were followed up for 3-18 years. The prevalence of cancer and dysplasia among the IBD patients who were diagnosed in northwestern Greece was analyzed and registered. Statistical analysis was performed assuming that this IBD cohort had the same risk of developing malignancies as the general population in Greece. RESULTS: Six of the 215 patients in this IBD cohort had cancer, and 20 of 126 patients for whom bowel biopsies were available had dysplasia. Three of these cases were high-grade dysplasia. There was no significant difference in the numbers of calculated and expected cases of IBD-related cancer at any sites except for the skin [2.7 vs. 2.0]. CONCLUSIONS: This IBD cohort did not appear to have an increased risk of cancer during the time period studied. It would be interesting to re-assess the risk after the second and third decades of follow-up.

Dermatofibrosarcoma protuberans occuring in a child

Dermatofibrosarcoma protuberans (DFSP) usually occurs in adults, however it can also occur in infancy and childhood. Diagnosis of DFSP in children is quite difficult given the rarity of the tumor and its variegated appearance. The behavior of this neoplasm is of borderline or intermediate malignancy with a high rate of recurrence but limited metastatic potential. We present the case of an eleven-year old boy who presented with a slightly raised, not tender lesion on his right shoulder. It had appeared two years before as a red-brown plaque and since then it had gradually grown to a nodule. An excisional biopsy was performed, and the diagnosis of DFSP was made based on the histological and immunohistochemical findings.

A fatal case of sclerosing mesenteritis

A 22-year-old patient was admitted because of abdominal pain and vomiting. Computed tomography diagnosed small intestinal malignancy. Ileal resection was performed, and the histological findings were consistent with sclerosing mesenteritis. The patient was treated with enteral nutrition, corticosteroids, azathioprine and methotrexate, but died 2 years later.

Orbital metastasis from prostatic carcinoma

A rare case of orbital metastasis from carcinoma of the prostate in a 76-year-old man who presented with pain in his left eye, mild proptosis and reduced visual acuity is reported. Cranial CT scanning demonstrated large bone metastases in the left orbit. The patient underwent orbital evisceration. The histopathological studies that were based on the morphological and immunohistochemical findings confirmed the histological diagnosis of orbital metastasis arising from prostatic carcinoma with neuroendocrine features.

Seropositive rheumatoid arthritis associated with Crohn's disease

In the present study we report a patient with long-standing seropositive rheumatoid arthritis, who developed Crohn's disease. We discuss the possible pathophysiologic mechanisms and their associations between these two entities.

An observational study of women with positive HPV-DNA tests and normal cytology and colposcopy

PURPOSE

High risk human papillomaviruses (HPV) are implicated in the aetiology of malignant cervical disease. The usefulness of HPV DNA tests in identifying women at risk of cervical cancer as an adjunct to cervical cytology is under evaluation.

PATIENTS AND METHODS

This is a retrospective analysis of 47 women positive for high risk HPV but with negative cytology and negative colposcopy at the start of the study. Women were observed for three years or more (in 96% cases) using six-monthly combined HPV DNA tests, cytological and colposcopic evaluation.

RESULTS

At the end of follow-up, 29/47 (62%) women were still positive for high risk HPV, 45/47 (96%) women had normal cytology and 47/47 (100%) women continued to have normal colposcopy.

CONCLUSIONS

Normal colposcopy has an excellent negative predictive value for HPV positive women with normal cytology. These women can be safely screened cytologically on a three-yearly basis.

Brucella melitensis infection stimulates an immune response leading to Kikuchi-Fujimoto disease

A 43-year-old Greek cattler with a history of brucellosis three months previously for which he was treated with sulfonamides for three weeks, was admitted to the hospital complaining of fever, arthralgias, night sweats, painful cervical and axillary lymph nodes as well as a weight loss of 8 kg in the previous four months. Since microbiological and serological studies did not give a specific diagnosis, an open cervical lymph node biopsy was performed. The histological examination revealed Kikuchi-Fujimoto disease. The etiology of the disease is unknown but viral, bacterial, protozoal and neoplastic as well as physicochemical agents may stimulate a particular immune response leading to Kikuchi-Fujimoto disease. Hereby, we present a case in which Kikuchi-Fujimoto disease followed brucella melitensis infection. This association permits us to hypothesize that the initial brucella melitensis infection three months previously triggered an immune response leading to Kikuchi-Fujimoto disease. The association of the disease with brucellosis is very important since these two entities share some similar characteristics, with brucellosis being relatively common in Europe. To our best knowledge, in the English language bibliography, this is the first reported case worldwide, though another similar case was described in the Spanish literature ten years ago.

Clear cell ovarian carcinoma in a pregnant woman with a history of infertility, endometriosis and unsuccessful IVF treatment

Ovarian cancer in pregnancy is a very rare event. We present here the case of a 37-year-old woman in whom a clear cell ovarian carcinoma was diagnosed in the first trimester of pregnancy. This patient had a history of infertility, endometriosis and two previous unsuccessful attempts of in vitro fertilization. Transvaginal sonography at six gestational weeks revealed a 6 x 4 cm ovarian cyst with an internal papillary excrescence. The cyst persisted throughout the first trimester, whereas the initial CA 125 value of 226 U/ml dropped to 61 U/ml at 12 gestational weeks. Exploratory laparotomy and cystectomy was performed at 14 weeks and the disease was classified as Stage Ic, arising in endometriosis. The couple decided to continue with pregnancy and the woman was followed by serial sonographic, MRI and CA 125 examinations. A cesarean section, hysterectomy, bilateral salpingo-oophorectomy and omentectomy was performed at 34 weeks. Histology and cytology were negative for recurrence. Four months later the woman and baby are doing well. We review cases of ovarian clear cell carcinoma diagnosed during pregnancy and discuss the association of endometriosis, infertility, infertility drugs and ovarian cancer.

The role of N-acetyltransferase-2 and glutathione S-transferase on the risk and aggressiveness of bladder cancer

N-acetyltransferase-2 (NAT-2) and Glutathione-S-transferase M1 and T1 (GSTM1 and GSTT1) polymorphism have been implicated in the detoxification of urothelial carcinogens, such as arylamines and polycyclic aromatic hydrocarbons. The results of epidemiological studies examining the role of NAT-2, GSTM1 and GSTT1 genotypes on the risk factors for bladder cancer were controversial, although suggesting that there may be an increased risk of the disease associated with these genotypes. The aim of the present study was to examine the independent effect and a possible interaction of NAT-2, GSTM1 and GSTT1 genotypes on the risk of bladder carcinogenesis, in the frame of a case-control study. We also investigated the possible association of specific genotype combinations with more aggressive disease in terms of tumor grading and local staging at the time of initial diagnosis. Between August 1996 and May 1998, 89 newly-diagnosed bladder cancer patients (transitional cell type) and 147 controls were included in the study. All patients were selected at the time of first diagnosis, done in the Department of Urology at the University Hospital of Ioannina, in north-western Greece. GSTM1 and NAT-2 deficient genotypes were found to be independently associated with the risk of bladder cancer (odds ratios 2.87 and 2.64, respectively). The GSTT1 genotype did not present any significant association with bladder cancer risk. We did not find a significant interaction between genotypes. These results could be explained by the independent activity of the two enzymes. Studies that will simultaneously examine the role of several genetic and environmental factors involved in bladder carcinogenesis are needed to give a global picture for the risk factors of bladder cancer and their potential interaction.

Transcription factor E2F-1 acts as a growth-promoting factor and is associated with adverse prognosis in non-small cell lung carcinomas

Numerous upstream stimulatory and inhibitory signals converge to the pRb/E2F pathway, which governs cell-cycle progression, but the information concerning alterations of E2F-1 in primary malignancies is very limited. Several in vitro studies report that E2F-1 can act either as an oncoprotein or as a tumour suppressor protein. In view of this dichotomy in its functions and its critical role in cell cycle control, this study examined the following four aspects of E2F-1 in a panel of 87 non-small cell lung carcinomas (NSCLCs), previously analysed for defects in the pRb-p53-MDM2 network: firstly, the status of E2F-1 at the protein, mRNA and DNA levels; secondly, its relationship with the kinetic parameters and genomic instability of the tumours; thirdly, its association with the status of its transcriptional co-activator CBP, downstream target PCNA and main cell cycle regulatory and E2F-1-interacting molecules pRb, p53 and MDM2; and fourthly, its impact on clinical outcome. The protein levels of E2F-1 and its co-activator CBP were significantly higher in the tumour area than in the corresponding normal epithelium (p<0.001). E2F-1 overexpression was associated with increased E2F-1 mRNA levels in 82% of the cases examined. The latter finding, along with the low frequency of E2F-1 gene amplification observed (9%), suggests that the main mechanism of E2F-1 protein overexpression in NSCLCs is deregulation at the transcriptional level. Mutational analysis revealed only one sample with asomatic mutation at codon 371 (Glu-->Asp) and one carrying a polymorphism at codon 393 (Gly-->Ser). Carcinomas with increased E2F-1 positivity demonstrated a significant increase in their growth indexes (r=0.402, p=0.001) and were associated with adverse prognosis (p=0.033 by Cox regression analysis). The main determinant of the positive association with growth was the parallel increase between E2F-1 staining and proliferation (r=0.746, p<0.001), whereas apoptosis was not influenced by the status of E2F-1. Moreover, correlation with the status of the pRb-p53-MDM2 network showed that the cases with aberrant pRb expression displayed significantly higher E2F-1 indexes (p=0.033), while a similar association was noticed in the group of carcinomas with deregulation of the p53-MDM2 feedback loop. In conclusion, the results suggest that E2F-1 overexpression may contribute to the development of NSCLCs by promoting proliferation and provide evidence that this role is further enhanced in a genetic background with deregulated pRb-p53-MDM2 circuitry.

Immunohistochemical HLA-DR antigen expression with lymphocyte subsets and proliferative activity in pterygium

The immunohistochemical expression of HLA-DR antigen, CD8, CD4, CD68, S1OO, PCNA and Ki-67 was performed in order to investigate the role of immune mechanisms in pterygium, in correlation with proliferative activity. A series of 98 surgically-excised pterygia, 18 pingueculae and 20 normal conjunctivae, was studied by the avidin-biotin method, on formalin-fixed, paraffin-embedded tissue. HLA-DR antigen was abundantly expressed in pterygium epithelial cells, whereas almost no expression was found in pinguecula and normal conjunctiva. A high value of Ki-67 and PCNA expression coexisted in the same areas with HLA-DR antigen expression in pterygium and a statistically significant positive correlation resulted between them (p = 0.002). Aberrant infiltration of inflammatory cells (CD4, CD8, CD68, S100) was detected in pterygium, while lower densities were found in pinguecula and conjunctiva. The data suggest that immunopathological mechanisms may contribute in the pathogenesis of pterygium. In addition, the aberrant HLA-DR antigen expression seems to be correlated with the growth fraction of the lesion.

Kikuchi-Fujimoto disease in Greece. A study of four cases and review of the literature

Kikuchi-Fujimoto disease is a rare disease first described in 1972 by Kikuchi and Fujimoto et al. (1,2). Clinically the disease presents with lymphadenitis usually in the cervical region. Most reported cases of Kikuchi-Fujimoto disease have been of Asian origin. The cause is unknown and the condition is self-limiting. Some kind of viral or postviral etiology has been implicated. Bacterial and protozoal organisms as well as various other antigens, chemical, physical and neoplastic, have also been postulated. An association with systemic lupus erythematosus has also been shown. Lymphadenitis, hepatomegaly and splenomegaly as well as leukopenia, elevated erythrocyte sedimentation rate and hepatic abnormalities are common findings. Fever, malaise, fatigue, headache, night sweats, nausea, vomiting, weight loss, cutaneous manifestations, and even neurological symptoms are other complaints. Histologically the lymph nodes show partial involvement with patchy irregular areas of necrosis in the paracortical area with absence of neutrophils. We describe four cases of Kikuchi-Fujimoto disease observed in Greece. Their characteristics are discussed, whilst a review of the literature is attempted.

Immunoelectron study of somatostatin, gastrin and glucagon in human colorectal adenocarcinomas and liver metastases

The aim of this study was to investigate the role and function of somatostatin, glucagon and gastrin in 35 colorectal adenocarcinoma and 25 liver metastases. The investigation was carried out at the electron immunocytochemistry level. Our results showed that well-differentiated tissues have the highest somatostatin levels compared to poorly-differentiated tumors while glucagon levels remain high. We also found gastrin immunoreactivity in cell membranes of poorly-differentiated primary adenocarcinoma tissues and in liver metastases. Low somatostatin expression, high glucagon expression and the presence of gastrin were found in tumors of poor grading and therefore poor prognosis.

Small bowel adenocarcinoma presenting as a first manifestation of Crohn's disease: report of a case, and a literature review

Small bowel Crohn's disease has been related to an increased incidence of small bowel adenocarcinoma, but the total number of reported cases is small. We present an interesting case of a young male patient with nephrolithiasis in childhood, an atypical intermittent history of diarrhoea also since his childhood, who developed obstructive ileus and underwent an urgent operation. The operation revealed a stenosis of the ileum owing to a mass, which proved to be a small bowel adenocarcinoma. One month later, the patient underwent a curative surgical resection of the tumour with additional lymphadenectomy, followed by chemotherapy for 6 months. Since then, the patient had mild diarrhoea but enteroclysis was normal. Approximately 2 years after the resection of the tumour, a new ileocolonoscopy demonstrated deep ulcerations of the terminal ileum and the adjacent area of the colon as well as anal ulcerations. The new biopsy specimens were convincing for Crohn's disease. There were no signs of residual or relapsing cancer. There is growing evidence that Crohn's disease is one of the triggering factors for the development of small bowel adenocarcinoma. Underlying Crohn's disease should be suspected in a young patient with an atypical history of diarrhoea and small bowel adenocarcinoma.

Amelanotic subungual malignant melanoma with multiple nodular local skin metastases

We present a 72-year-old man with a subungual amelanotic malignant melanoma (MM) on the right first toe with numerous local nodular metastases after trauma and without regional lymph node involvement. Most of the lesions were angiomatous (reddish blue), and some had a hyperkeratotic surface, clinically resembling Kaposi sarcoma. Results of biopsies performed on skin taken from the toe and from a metastatic lesion of the tibia revealed a classic case of amelanotic MM. This case has 2 interesting points: the clinical presentation of the metastatic lesions and the topical spreading of the lesions, which was initiated after traumatic injury of the prime lesion.

u-PA expression in benign, borderline and malignant ovarian tumors

The malignant potential of solid tumors is related to their ability to invade adjacent tissue and to metastasize. The plasminogen activation system is one of the critical factors in tumor progression since it is involved in tumor invasion and metastasis. This study was performed to examine the expression of u-PA in benign, borderline and malignant tumors of the ovary by immunohistochemical evaluation on formalin-fixed, paraffin-embedded specimens applying monoclonal antibody 3689 directed to the b-chain of u-PA. Normal epithelial cells of the ovary (n = 5) showed no staining of u-PA but some stromal cells were slightly stained. Invasive carcinomas (n = 16) and borderline tumors (n = 15) showed a moderate to strong diffuse cytoplasmic staining. Benign tumors (n = 20) showed a variety of staining. The observation of randomly positive u-PA stromal cells is noteworthy. The percentage of u-PA-positive tumors was higher in carcinomas than in other tumors. There was no correlation with other known risk factors of malignancy such as differentiation, stage or type of tumor. In conclusion there are noticeable differences in u-PA expression among ovarian tumors and u-PA increase in ovarian tumors can be attributed to an increased diffuse cytoplasmic content in the neoplastic epithelial cells.

Antitumour and toxic effects on Wistar rats of two new platinum complexes

BACKGROUND

Cancer chemotherapy in humans based on metal complexes started at the clinical level in the late 1970s with the use of cisplatin, which forms intra-strand cross-links with DNA.

METHODS

Two new platinum complexes of cis-geometry with the amino acids inosine (ino) and l-alanine (ala), Pt(ino)2Cl2 and cis-[Pt(NH3)2(ala)](NO3), respectively, were synthesized and pure samples were obtained by means of flash chromatography. These complexes were tested on benzo(a)pyrene-induced tumours in Wistar rats to detect their antitumour and toxic effects.

RESULTS

There was a statistically significant prolongation of the mean survival time of the animals in the two groups tested (272 +/- 18 days and 246 +/- 26 days, respectively) compared to the control group (195 +/- 22 days) (P < 0.001). Toxic effects included a decrease in leucocyte cell count, mild haemolysis, mild haematuria, mild hepatotoxicity, elevated body temperature and hair loss. All of these effects were reversible after drug discontinuation.

CONCLUSIONS

The two new platinum complexes described here appear to have an effective antitumour activity without severe toxicity when tested on Wistar rats.

Expression of gelatinase-A (MMP-2) in human colon cancer and normal colon mucosa

Proteolytic enzymes, such as type IV collagenases (MMP-2 gelatinase A, 72-kD type IV collagenase and MMP-9 gelatinase B, 92-kD type IV collagenase) play an important role in tumor invasion and metastasis. In the present study the levels of MMP-2 antigenic concentration and immunohistochemical staining were compared in paired colorectal tumor (n = 64) and background colon tissue of the same patients with clinical and pathological staging. The antigenic concentrations were found to be statistically significantly higher in cancer tissue (mean 11.29 ng/mg protein) than in corresponding normal mucosa (10.23 ng/mg protein) (p = 0.008). There was also a positive correlation between MMP-2 antigenic concentration and clinicopathologic parameters such as grade (p < 0.001) and Dukes' stage (p = 0.001), but not with lymph node involvement. Immunohistological localization of MMP-2 was observed in tumor as well as in stromal cells. Staining intensity increased from adenoma to adenocarcinoma. The degree of staining was associated with grade (p < 0.001), Dukes' stage (p < 0.001) and lymph node involvement (p < 0.001).

Comparative study of serotonin and bombesin in adenocarcinomas and neuroendocrine tumors of the colon

The aim of this study was to investigate serotonin and bombesin expression in colorectal adenocarcinomas and neuroendocrine colorectal tumors to clarify their role in the progression of colon cancer. The investigation was carried out by electron microscope immunocytochemistry. The ultrastructural study revealed that some cases of colorectal adenocarcinomas were characterized by the presence of amphicrine cells containing endocrine granules and mucus granules. Poorly differentiated adenocarcinomas and liver metastases were poorly granulated compared with highly differentiated tumors. Neuroendocrine tumors nevertheless were characterized by the presence of numerous malignant neuroendocrine cells filled with secretory granules and mucus granules. Bombesin appeared to be located in enterochromaffin-like endocrine cells, which are primarily responsible for the production of serotonin. In colorectal adenocarcinomas there was an inverse correlation between serotonin levels and the degree of differentiation. High serotonin levels characterized colorectal adenocarcinomas with composite phenotype and colorectal neuroendocrine tumors. Increased bombesin expression was correlated with colorectal adenocarcinomas exhibiting poor histological grade and their liver metastases. In conclusion, the findings suggest that high serotonin levels may be an indicator of neuroendocrine differentiation, and bombesin may be a useful marker for colorectal adenocarcinomas with aggressive behavior,

C-MYC and IGF-II mRNA-binding protein (CRD-BP/IMP-1) in benign and malignant mesenchymal tumors

Mouse coding region determinant-binding (mCRD-BP) and human IGF-II mRNA-binding 1 (hIMP-1) proteins are orthologous mRNA-binding proteins that recognize c-myc and IGF-II mRNA, respectively, and regulate their expression posttranscriptionally. Here, we confirm that human CRD-BP/IMP-1 binds to c-myc mRNA and that it is predominantly expressed in fetal tissues. Moreover, hCRD-BP/IMP-1 expression was detected in cell lines of neoplastic origin and in selected primary tumors. In a series of 33 malignant and 10 benign mesenchymal tumors, 73% and 40%, respectively, were found to express hCRD-BP/IMP-1. In particular, expression was significant in 14 Ewing's sarcomas, all of which were positive. The data suggest that hCRD-BP/IMP-1 plays a role in abnormal cell proliferation in mesenchymal tumors.

Mast cell distribution and density in the normal uterus--metachromatic staining using lectins

This study investigates the number and the distribution of mast cells in the normal human uterus. Reliability of results was ensured by prompt tissue fixation and the use of biotin-labelled lectins in conjunction with the avidin-biotin peroxidase complex (ABC) method. This design revealed that mast cells are, indeed, normal constituents of the human uterus. They occur in large numbers in the myometrium, but are only scanty in the endometrium where they tend to be confined to the stratum basalis. The mean mast cell counts per high power field (MC/HPF), after staining with Canavalia ensiformis agglutinin (Con A), were 17.9MC/HPF in the inner half of the myometrium, and 8.3MC/HPF in the outer half of the myometrium; 2.7MC/HPF in the basalis, and 0.3MC/HPF in the functionalis (P<0.05). There are no apparent differences in the number of mast cells between the normal proliferative and secretory phase endometrium, however, endometrial mast cells are considerably reduced and, apparently, depleted of metachromatic granules during the immediate pre-menstrual phase of the menstrual cycle. It is presumed that this, almost exclusive, presence of mast cells in the basal layer of the endometrial matrix, combined with the discharge of their cytoplasmic granules towards the end of the cycle, may be related with the contracting process preceding menstruation. On the other hand, the relative paucity of mast cells in the functional layer may contribute to the immune tolerance of the gestational endometrium to the implantation of the blastocyst.

Mesenchymal chondrosarcoma of soft tissues of the calf

Mesenchymal chondrosarcomas are distinct from conventional and dedifferentiated chondrosarcomas and are quite rare, making up less than 2% of all chondrosarcomas. We describe a mesenchymal chondrosarcoma of the soft tissues of the calf and review the differential diagnosis of this poorly understood entity.

Long-term prognostic significance of HSP-70, c-myc and HLA-DR expression in patients with malignant melanoma

AIM

Use of molecular markers indicative of the tumour oncogenic potential and host response may enhance our prognostic information for more effective treatment of melanoma patients. The roles of HSP-70 protein, c-myc oncogene and HLA-DR antigen expression were examined in melanoma patients and related to prognostic factors, recurrence rate and long-term survival.

METHODS

Forty patients with tumours thicker than 1 mm were included in this study. All had elective node dissection and were followed for at least 7 years. Twenty-two had microscopic nodal metastases. Both primary melanoma tumour and lymph nodes were examined for the immunohistochemical expression of HSP-70 protein, c-myc oncogene and HLA-DR antigen.

RESULTS

Eighteen patients had a recurrence (45%) and 23 patients survived overall (57.50%). Positive HSP-70 expression was observed in 52.50% of the primary melanomas and was associated with improved overall survival, especially in the patient group with tumours > or = 1.5 mm (70%vs 26.70%, P=0.0159). C-myc oncogene was overexpressed in 47.50% and HLA-DR antigen in 42.50% of the primary melanomas, but no correlation with survival was observed. The expression profile of these molecular markers in the primary tumour did not predict the status of regional nodes. HLA-DR expression in lymph nodes was observed exclusively in the nodal tissue surrounding the metastatic melanoma tumour in five patients.

CONCLUSIONS

The immunohistochemical expression profile of HSP-70 but not of c-myc oncogene or HLA-DR antigen in the primary melanoma tumour could be of certain value in the identification of patients with graver prognosis who may benefit from more aggressive therapeutic strategies.

Lectin-binding patterns in normal, hyperplastic and neoplastic endometrium: the prognostic value of concanavalin A

Lectins are proteins and glycoproteins of non-immune origin which bind specifically to carbohydrate residues, agglutinate cells and/or precipitate complex carbohydrates. Lectin-binding patterns in normal, hyperplastic and neoplastic endometria were studied using four biotinylated lectins (Con A, LCA, e-PHA, l-PHA) and the avidin-biotin-peroxidase technique. Canavalia ensiformis agglutinin (ConA) and Lens culinaris agglutinin (LCA) reacted strongly with the luminal borders and the cytoplasm of epithelial cells but, whilst in normal and benign endometrial tissues the cytoplasmic staining was confined to the apical and the basal aspect of the cells, in endometrial carcinomas and in some atypical hyperplasias lectin binding also occurred in the lateral cytoplasm (Con-A-lat), although in differing proportions of cells. Interestingly, extensive Con-A-lat in the tumour cells was much more frequent in non-endometrioid carcinomas (P<0.05) and was significantly associated with poor histological differentiation (P<0.0001), low oestrogen and progesterone receptor content (P<0.01 and P=0.0001, respectively) and an unfavourable long-term survival (P<0.05). With Phaseolus vulgaris erythroagglutinin (e-PHA) and leucoagglutinin (l-PHA) a linear, rather inconsistent, staining at the level of the basement membranes was observed in the glands: this, also noted with LCA, appeared intact in normal and hyperplastic glands without cytological atypia, and fragmented or absent in malignant glandular structures and in most hyperplastic glands showing cytological atypia. It is concluded that changes in the distribution of lectin-binding molecules in the endometrial cells are associated with the malignant state, whilst the extent of Con-A-lat reflects the biological behaviour of the tumours.

Immunohistochemical expression of cathepsin D in laryngeal epithelial lesions: correlation with CD44 expression, p53 and Rb status and proliferation associated indices

Clinical studies in several tumour types have shown a strong correlation between cathepsin D expression and tumour progression. Immunohistochemical staining for cathepsin D (clone D13A) was performed in paraffin embedded-tissues from 39 invasive squamous cell carcinomas, 13 in situ carcinomas, 35 cases of dysplasia, 10 papillomas and 17 cases of keratosis. The association between cathepsin D expression and CD44, p53, Rb proteins and proliferation indices (Ki-67, PCNA) was assessed by univariate analysis. Cathepsin D was highly positive in the groups of carcinomas compared to other lesions (p < 0.0001). A statistically significant correlation of cathepsin D expression with CD44 expression was observed in invasive cancers (p = 0.037). The relationship of cathepsin D immunoreactivity with p53, Rb and proliferation indices was insignificant. The results show that cathepsin D is expressed in a higher proportion of cancerous lesions of the larynx than in non cancerous or premalignant lesions, a fact which suggests that cathepsin D may be involved in laryngeal tumour cell growth process.

The loss of lectin reactivity from human endometrium is a feature of malignant change

Changes in the cell surface glycoproteins were investigated in endometrial adenocarcinomas using eight biotin-labelled lectins (Con A, LCA, WGA, e-PHA, l-PHA, SBA, PNA, LTA) which select for the major classes of N-linked and O-linked oligosaccharides. The tissues studied were 14 normal endometria, 20 cases of simple hyperplasia and 30 endometrial adenocarcinomas. Sections were cut at 5 microns from formalin fixed paraffin embedded blocks and were stained with an avidin-peroxidase method. All normal and hyperplastic endometria contained the full range of expected saccharides (positive staining for Con A, LCA, WGA, SBA, PNA, LTA, e-PHA and l-PHA). By contrast, over half of the endometrial adenocarcinomas exhibited a loss of galactosamine (56.7%) and over a third of them failed to reveal galactose (36.7%) and fucose (30.0%) (negative staining for SBA, PNA and LTA, respectively). Interestingly, following neuraminidase treatment, galactose was identified in all adenocarcinomas studied, but the expression of galactosamine and fucose was unaffected. There was a discrete linear staining at the level of the basement membranes in a proportion of endometrial glands treated with e-PHA, l-PHA and LCA; this was continuous in normal and hyperplastic endometria, while it was fragmentary in endometrial adenocarcinomas. The loss of galactosamine reactivity from endometrial adenocarcinomas was significantly correlated with high grade differentiation, and also with the more frequent occurrence of a poor oestrogen (ER) and progesterone (PR) receptor status and with an unfavourable 5-year survival. No relationship was found between fucose reactivity and tumour differentiation, stage of disease, hormone receptor status or prognosis. It is concluded that galactosamine loss, together with reduced fucose expression, is a common feature of endometrial malignancy, and that galactosamine deficient tumours may reflect a more aggressive biological behaviour.

Topographical immunohistochemical expression of bcl-2 protein in human liver lesions

Immunolocalization of the bcl-2 protein was investigated in 60 hepatocellular carcinomas, 10 cholangiocarcinomas. 15 metastatic adenocarcinomas as well as in 37 non-neoplastic liver lesions. The three-step immunoperoxidase method was performed in archival, routinely processed material. bcl-2 protein was not identified either in neoplastic, dysplastic or normal hepatocytes, whereas it was observed in bile ductules and small bile duct epithelia, but not in the epithelium lining large bile ducts. All cases of cholangiocarcinoma and 60% of metastatic adenocarcinomas were bcl-2 positive. bcl-2 appears to be an additional marker in distinguishing hepatocellular carcinoma from cholangiocarcinoma or metastatic adenocarcinoma. Also, bcl-2 does not seem to be involved in human liver hepatocyte survival.

Squamous cell carcinoma of the penis arising from balanitis xerotica obliterans

Penile squamous cell carcinoma arising from balanitis xerotica obliterans is rarely reported. We describe a 58-year-old man in whom penile squamous cell carcinoma developed after 25 years of observation for balanitis xerotica obliterans. It is important to recognize the possibility of this uncommon complication of balanitis xerotica obliterans, because survival of patients with squamous cell carcinoma depends on early diagnosis and treatment.

Overexpression of C-myc, Ras and C-erbB-2 oncoproteins in carcinoma of unknown primary origin

The role of oncogenes in carcinoma of unknown primary site (CUP) has not yet been elucidated. In the present study the expression of the c-myc p62, ras p21 and c-erB-2 p185 oncoproteins were studied by a 3-step immunoperoxidase technique in 26 cases of CUP. Positive immunoreactivity was observed in 96% of the cases for c-myc, 92% for ras and in 65% for c-erb-2, with at least half of tumor cells labelled in 85%, 92% and 58% respectively. The degree of staining intensity was considered moderate or strong in more than half of the cases for all oncogene products. In conclusion, our results showed that patients with CUP have an extremely high overexpression of all three oncogenes studied. Nevertheless, the biological role of these overexpressed oncoproteins, their relationship with different histological or clinical parameters and their diagnostic or prognostic value need further evaluation.

HLA-DR antigen expression in pterygium epithelial cells and lymphocyte subpopulations: an immunohistochemistry study

The purpose of our study was to investigate the role of immune mechanisms in the pathogenesis of pterygium using an immunohistochemical technique. Our material consisted of 35 surgically excised pterygia and 7 samples of normal conjunctiva obtained from an equal number of patients. HLA-DR antigen expression in epithelial cells, B-cells, suppressor and helper lymphocytes, Langerhans' cells, and monocytes/macrophages were studied immunohistochemically in frozen sections using anti-human HLA-DR, anti-CD22, anti-CD8, anti-CD4, anti-CD1a, and anti-LeuM5 monoclonal antibodies. Aberrant HLA-DR antigen expression in epithelial cells was detected in 30 of 35 cases of pterygium. Epithelial cells in samples of normal conjunctiva were found to be negative in HLA-DR antigen expression. HLA-DR antigen expression in pterygium was found to be closely related to the density of T4 cells and, especially, of CD4 lymphocytes. The present findings suggest that an immunopathologic mechanism plays a role in the pathogenesis of pterygium.

Enhancement of the antineoplastic effect of anticarcinogens on benzo[a]pyrene-treated Wistar rats, in relation to their number and biological activity

Naturally occurring anticarcinogens, such as vitamins C and E, and the microelement selenium were found to inhibit the induction of benzo[a]pyrene-induced malignant tumors in Wistar rats to various extends. The antineoplastic effect of the tested anticarcinogens is gradually increased according to the number of inhibitors selected. To date the maximum action against malignancy is manifested by use of the above three inhibitors. In the group of rats receiving vitamins C, E and selenium, the prolongation of life induced by adding more than one anticarcinogen to the treatment regime reached, and in some cases surpassed, the normal life expectancy of the rats. It is expected that by adding even more anticarcinogens, the antineoplastic potency (Ap) of the inhibitors will be further improved. These results encouraged us to conduct a clinical trial in terminal human cancer cases, in conjunction with the usual treatments of surgery or chemotherapy and irradiation.