Nodal assessment in Endometrial Atypical Hyperplasia

OBJECTIVE

Atypical endometrial hyperplasia (AH) is the neoplastic precursor more often associated with endometrial cancer (EC). Nowadays, 25-50% of patients subjected to hysterectomy for preoperative AH are diagnosed with EC at the final pathological analysis. Furthermore, there is no consensus on which preoperative AH patients would benefit from sentinel lymph node mapping. This study aimed to evaluate nodal assessment and preoperative cancer risk factors in preoperative AH patients undergoing nodal surgical staging.

METHODS

Patients undergoing surgical treatment for AH were retrospectively included in the analysis. Patients were divided into two groups (AH and EC groups) based on the final surgical pathology. The ESGO/ESTRO/ESP risk classification was used for EC cases.

DESIGN

Retrospective study.

RESULTS

Of the 207 AH patients treated, 152 cases met the inclusion criteria. Among preoperative AH patients with final EC diagnosis, thirty-nine patients were in the low-risk group (25.7%), 8 in the intermediate-risk group (5.3%), 4 in high-intermediate (2.6%), and 3 patients were allocated in the high-risk group (2.0%). 54 total patients underwent nodal surgical staging. Only one nodal micrometastasis (0.7%) was found at ultrastaging. Multivariate analysis showed abnormal uterine bleeding (AUB) (p = 0.01), hypertension (p <0.01), and endometrial thickness > 20 mm (p = 0.02) statistically more represented in patients with EC at final surgical analysis.EC risk was 2.9 (95% CI 1.29-6.48) in AUB, 2.7 (95% CI 1,06-6,92) in hypertension, and 3.1 (95% CI 1.19-7.97) in endometrial thickness > 20 mm cases.

LIMITATIONS

The present study has limitations inherent in its retrospective nature.

CONCLUSION

The overall risk of nodal metastases in preoperative AH patients was low. Conversely, 9.9% of the preoperative AH patients belonged to the intermediate or high-risk group for EC at the final histological examination. Preoperative cancer risk factors would identify AH patients for whom nodal staging could be suggested.

Peripherally Inserted Central Venous Catheters (PICC) versus totally implantable venous access device (PORT) for chemotherapy administration: a meta-analysis on gynecological cancer patients

Background and aim:

Ninety-four thousand gynecological cancer diagnoses are performed each year in the United States. The majority of these tumors require systemic adjuvant therapy. Sustained venous access was overcome by indwelling long-term central venous catheter (CVC). The best choice of which CVC to use is often arbitrary or dependent on physician confidence. This meta-analysis aims to compare PORT and peripherally inserted central catheter (PICC) outcomes during adjuvant treatment for gynecological cancer.

Methods:

Meta-analysis Of Observational Studies in Epidemiology (MOOSE) and the preferred reporting items for systematic reviews and meta-analyses statement (PRISMA)were used to conduct the meta-analysis.

Results:

1320 patients were included, 794 belonging to the PORT group and 526 to the PICC group. Total complication rates were fewer in the PORT group, p = 0.05. CVC malfunction was less frequent in the PORT group than in the PICC group, p <0.01. Finally, thrombotic events were less expressed in the PORT group than in the PICC group, p = 0.02. No difference was found in operative complication, migration, malposition, extravasation, infection, and complication requiring catheter removal.

Conclusions:

PORT had fewer thrombotic complications and fewer malfunction problems than PICC devices. Unless specific contraindications, PORTs can be preferred for systemic treatment in gynecological cancer patients. (www.actabiomedica.it)

Obesity, an independent predictor of pre and postoperative tumor grading disagreement in endometrial cancer

INTRODUCTION

Obesity is a known independent risk factor for endometrial cancer (EC), and obese patients have a 4.7-fold increased risk compared to the general population to develop the neoplasm. To date, a general pre and postoperative tumor grading agreement from 53 % to 82 % is reported for endometrial analysis, and a consensus on which factors might influence the tumor grading discordance is still absent. Furthermore, although obesity alters the endometrial microenvironment, no studies investigated the role of obesity in the grading agreement of EC patients. This study aims to analyze the role of obesity in the pre and postoperative tumor grading agreement.

MATERIALS AND METHODS

A retrospective analysis was conducted on EC cancer women subjected to surgical treatment. Upgrading discordance was defined as higher tumor grading on final pathological analysis compared to tumor grading on the preoperative examination. Downgrading discordance was defined as a lower tumor grading at the postoperative surgical specimen analysis compared to the preoperative biopsy.

RESULTS

Of the 293 selected patients, 245 were included in the analysis. One hundred and forty nine (60.8 %) patients were tumor grade G1, 52 (21.2 %) G2, and 44 (18.0 %) G3. Grading agreement was 83.9 % for G1 patients, 51.9 % for G2 patients, and 83.3 % for G3 patients. The multivariate analysis showed obesity (BMI > 30 kg/m²) as significant factor influencing pre and postoperative grading agreement (p = 0.014, Odds Ratio 2.036, 95 % Confidence Interval 1.141-3.635).

CONCLUSIONS

Our study for the first time showed obesity as the only factor in the multivariate analysis lowering the pre and postoperative tumor grading concordance. Grade 2 tumor was the factor that most frequently disagreed with the final surgical specimen analysis both in the general and in obese patients.

Transperitoneal versus extraperitoneal laparoscopic aortic lymph nodal staging for locally advanced cervical cancer: A systematic review and meta-analysis

Cervical cancer is the fourth most common neoplasm in women. In locally advanced cervical cancers, the international guidelines recommend nodal aortic assessment. Two techniques have been described to perform laparoscopic aortic lymphadenectomy: transperitoneal laparoscopic lymphadenectomy (TLL) and extraperitoneal laparoscopic lymphadenectomy (ELL). This meta-analysis aims to compare the surgical outcomes of TLL and ELL for staging purposes. The systematic review was carried out in agreement with the preferred reporting items for systematic reviews and meta-analyses statement (PRISMA). Two hundred and twenty studies were analyzed, and 19 studies were included in the review (7 for TLL and 12 for ELL group). 1112 patients were included in the analysis: 390 patients were included in group 1 and 722 patients in group 2.38 patients (9.7%) in the TLL group and 69 (9.5%) patients in the ELL group developed major complications. The analysis of all complications (intraoperative and postoperative) rate through pooled analysis did not show a significant difference between the two groups (p = 0.979), although a significantly higher intraoperative complication rate (p = 0.018) occurred in the TLL group compared to ELL. No significant differences were found between groups for BMI (p = 0.659), estimated blood loss (p = 0.889), length of stay (p = 0.932), intraoperative time (p = 0.932), conversion to laparotomy rate (p = 0.404), number of lymph node excised (p = 0.461) and postoperative complication (p = 0.291). TLL approach shows a higher rate of intraoperative complications, while no significant difference was found between the two techniques when postoperative complications were analyzed.

Intraperitoneal hemorrhage following primary cytoreductive surgery for ovarian cancer: Successful treatment with superior epigastric artery embolization

Hemoperitoneum often occurs due to abdominal trauma, abdominal tumors, gastro-intestinal perforation and more rarely it's spontaneous due to coagulopathies. Superior epigastric artery (SEA) iatrogenic damage is rarer than the Inferior epigastric artery injury, it may occur during laparotomy and, in most cases, it causes a rectus muscle hematoma. We present the case of a caucasian 44 years-old-woman with hemoperitoneum after cytoreductive surgery for ovarian cancer. Active bleeding from the distal branch of the SEA was diagnosed at computed tomography and coil embolization followed by surgical laparotomic drainage of the hemoperitoneum was performed. After initial resolution, active bleeding from the same vessel was observed. Further embolization of the same vessel was necessary to stop bleeding. Ultrasound follow-up showed a complete resolution of the hemoperitoneum.

Obstetrics outcomes after complete and partial molar pregnancy: Review of the literature and meta-analysis

The hydatidiform mole is a rare gynecological disease rising from the trophoblastic. Post-molar pregnancies have an extremely variable course, varying from repeated abortions, stillbirths, preterm births, live births, or recurring in further molar pregnancies. Literature on obstetric outcomes following molar pregnancy is poor, often including monocentric studies, and with data collected from national databases. This review and meta-analysis aim to analyze the obstetric outcomes after conservative management of complete (CHM) and partial (PHM) molar pregnancies. The meta-analysis was performed following the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) and the preferred reporting items for systematic reviews and meta-analyses statement (PRISMA). Six studies met the inclusion. Of the total 25,222 patients, 13,129 complete (52.1 %) and 12,093 partial (47.9 %) molar pregnancies were included. Live births rate after CHM was statistically higher (p = 0.002) compared to the live births after PHM (53.6 % vs. 51.0 %, 3266 vs. 1807 cases, respectively). Studies showed heterogeneity I² = 57.7 %, pooled proportion = 0.2 %, and 95 % Confidence Interval (CI) 0.6 to 0.9. No statistically significant difference was demonstrated for ectopic pregnancies (p = 0.633), miscarriage (p = 0.637), preterm birth (p = 0.865), stillbirth (p = 0.911), termination of pregnancy (p = 0.572), and complete molar recurrence (p = 0.580) after CHM and PHM. Partial molar recurrence occurred more frequently after PHM than CHM (0.4 % vs. 0.3 %, 52 vs. 37 cases, respectively, p = 0.002). Careful counseling on the obstetric subsequent pregnancies outcomes should be provided to patients eager for further pregnancy and further studies are needed to confirm these results.

Endometrial stromal sarcoma: A review of rare mesenchymal uterine neoplasm

OBJECTIVE

This review aims to analyze the pathological aspects, diagnosis and treatment of rare mesenchymal uterine tumors.

METHODS

On August 2019, a systematic review of the literature was done on Pubmed, MEDLINE, Scopus, and Google Scholar search engines. The systematic review was carried out in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes statement (PRISMA). The following words and key phrases have been searched: "endometrial stromal sarcoma", "low-grade endometrial stromal sarcoma", "high-grade endometrial stromal sarcoma", "uterine sarcoma", "mesenchymal uterine tumors" and "uterine stromal sarcoma". Across these platforms and research studies, five main aspects were analyzed: the biological characteristics of the neoplasms, the number of cases, the different therapeutic approaches used, the follow-up and the oncological outcomes.

RESULTS

Of the 94 studies initially identified, 55 were chosen selecting articles focusing on endometrial stromal sarcoma. Of these fifty-five studies, 46 were retrospective in design, 7 were reviews and 2 randomized phases III trials.

CONCLUSION

Endometrial stromal sarcomas are rare mesenchymal uterine neoplasms and surgery represents the standard treatment. For uterus-limited disease, the remove en bloc with an intact resection of the tumor (without the use of morcellation) is strongly recommended. For advanced-stage disease, the standard surgical treatment is adequate cytoreduction with metastatectomy. Pelvic and para-aortic lymphadenectomy is not recommended in patients with Low-grade Endometrial Stromal Sarcoma (ESS), while is not clear whether cytoreduction of advanced tumors improves patient survival in High-grade ESS. Administration of adjuvant radiotherapy or chemotherapy is not routinely used and its role is still debated.

Correlation between low folate levels and hyperhomocysteinemia, but not with vitamin B12 in hypertensive patients

INTRODUCTION

Hypertension is considered to be among the most important risk factors for cardiovascular and cerebrovascular diseases. In recent years, several investigators have reported that high plasma levels of total homocysteine (t-hcy) has a key role in the development of hypertension, and the deficiency of B complex vitamins could increase the risk of hypertension. The purpose of this study was to investigate the relationship between plasma homocysteine, folate and vitamin B12 in hypertensive patients.

MATERIALS AND METHODS

In 116 patients with hypertension and 81 healthy subjects, total plasma homocysteine, vitamin B12 and folate levels were measured.

RESULTS AND DISCUSSION

Homocysteine was significantly higher in patients than in control subjects (22.9±3.5 versus 9.0±2.3 μmol/L respectively, p<0.001); the folate plasma concentrations in hypertensive patients were significantly lower than in control subjects (6.7±5.0 ng/ml and 9.0±4.4 ng/ml respectively, p<0.05). Moreover, no differences in vitamin B12 plasma levels were observed when comparing the levels of hypertensive patients and those of the controls (440±223 pg/ml vs 491±185 pg/ml respectively, p>0.05). Our results confirmed that, as previously observed, elevated t-hcy levels and low folate levels, but not vitamin B12 levels, are significantly associated with hypertension.

Elevated cerebrospinal fluid and plasma homocysteine levels in ALS

BACKGROUND

High cerebrospinal fluid (CSF) and plasma levels of homocysteine (HC) have been reported in certain neurodegenerative disorders, such as Alzheimer's, Parkinson's diseases and, recently, amyotrophic lateral sclerosis (ALS).

OBJECTIVES

To assay the CSF and plasma levels of HC in ALS patients and controls, and to evaluate the relationship between HC levels and clinical variables of the disease.

METHODS

Cerebrospinal fluid from sixty-nine (M/F 1.87) and plasma from sixty-five ALS patients (M/F 1.83) were taken and stored at -80 degrees C until use. Controls (CSF = 55; plasma = 67) were patients admitted to our hospital for neurological disorders with no known relationship to HC changes. CSF and plasma from ALS patients and controls were obtained as a necessary step of the diagnostic workup. HC levels in CSF and plasma were assayed using a high performance liquid chromatograph (HPLC) and a fluorimeter detector.

RESULTS

The median level of total HC in the CSF of ALS patients was 0.46( )microM, significantly higher than that of the controls (0.24 microM, +91.6%, P < 0.001). A similar trend was observed when HC was assayed in plasma (ALS, 12.4 microM vs. controls, 7.26 microM, +70.8%, P < 0.001). The CSF and plasma HC levels showed no relationship with the disease progression, age at onset, and the site of onset.

CONCLUSIONS

Homocysteine is a biochemical marker in ALS, and it might be related to the pathophysiology of the disease.

Kinetics of the lipoperoxyl radical-scavenging activity of indicaxanthin in solution and unilamellar liposomes

The reaction of the phytochemical indicaxanthin with lipoperoxyl radicals generated in methyl linoleate methanol solution by 2,2'-azobis(2,4-dimethylvaleronitrile), and in aqueous soybean phosphatidylcholine unilamellar liposomes by 2,2'-azobis(2-amidinopropane)hydrochloride, was studied. The molecule acts as a chain-terminating lipoperoxyl radical scavenger in solution, with a calculated inhibition constant of 3.63 x 10(5) M(-1) s(-1), and a stoichiometric factor approaching 2. Indicaxanthin incorporated in liposomes prevented lipid oxidation, inducing clear-cut lag periods and decrease of the propagation rate. Both effects were concentration-dependent, but not linearly related to the phytochemical concentration. The consumption of indicaxanthin during liposome oxidation was remarkably delayed, the lower the concentration the longer the time-interval during which it remained in its native state. Indicaxanthin and alpha-tocopherol, simultaneously incorporated in liposomes, exhibited cooperative antioxidant effects and reciprocal protective interactions. The extent of synergism decreased at the increase of the ratio (indicaxanthin)/(alpha-tocopherol). A potential antioxidant mechanism of indicaxanthin is discussed in the context of the chemistry of the molecule, and of the possible reactivity of a short-lived intermediate.

Cytoprotective effects of the antioxidant phytochemical indicaxanthin in β-thalassemia red blood cells

Antioxidant phytochemicals are investigated as novel treatments for supportive therapy in beta-thalassemia. The dietary indicaxanthin was assessed for its protective effects on human beta-thalassemic RBCs submitted in vitro to oxidative haemolysis by cumene hydroperoxide. Indicaxanthin at 1.0-10 microM enhanced the resistance to haemolysis dose-dependently. In addition, it prevented lipid and haemoglobin (Hb) oxidation, and retarded vitamin E and GSH depletion. After ex vivo spiking of blood from thalassemia patients with indicaxanthin, the phytochemical was recovered in the soluble cell compartment of the RBCs. A spectrophotometric study showed that indicaxanthin can reduce perferryl-Hb generated in solution from met-Hb and hydrogen peroxide (H2O2), more effectively than either Trolox or vitamin C. Collectively our results demonstrate that indicaxanthin can be incorporated into the redox machinery of beta-thalassemic RBC and defend the cell from oxidation, possibly interfering with perferryl-Hb, a reactive intermediate in the hydroperoxide-dependent Hb degradation. Opportunities of therapeutic interest for beta-thalassemia may be considered.

Collagen binding is a key factor for the hemorrhagic activity of snake venom metalloproteinases

Snake venom metalloproteinases (SVMPs) are multifunctional enzymes involved in several symptoms following snakebite, such as severe local hemorrhage. Multidomain P-III SVMPs are strongly hemorrhagic, whereas single domain P-I SVMPs are not. This indicates that disintegrin-like and cysteine-rich domains allocate motifs that enable catalytic degradation of ECM components leading to disruption of capillary vessels. Interestingly, some P-III SVMPs are completely devoid of hemorrhagic activity despite their highly conserved disintegrin-like and cysteine-rich domains. This observation was approached in the present study by comparing the effects of jararhagin, a hemorrhagic P-III SVMP, and berythractivase, a pro-coagulant and non-hemorrhagic P-III SVMP. Both toxins inhibited collagen-induced platelet aggregation, but only jararhagin was able to bind to collagen I with high affinity. The monoclonal antibody MAJar 3, that neutralizes the hemorrhagic effect of Bothrops venoms and jararhagin binding to collagen, did not react with berythractivase. The three-dimensional structures of jararhagin and berythractivase were compared to explain the differential binding to collagen and MAJar 3. Thereby, we pinpointed a motif within the Da disintegrin subdomain located opposite to the catalytic domain. Jararhagin binds to both collagen I and IV in a triple helix-dependent manner and inhibited in vitro fibrillogenesis. The jararhagin-collagen complex retained the catalytic activity of the toxin as observed by hydrolysis of fibrin. Thus, we suggest that binding of hemorrhagic SVMPs to collagens I and IV occurs through a motif located in the Da subdomain. This allows accumulation of toxin molecules at the site of injection, close to capillary vessels, where their catalytic activity leads to a local hemorrhage. Toxins devoid of this motif would be more available for vascular internalization leading to systemic pro-coagulant effects. This reveals a novel function of the disintegrin domain in hemorrhage formation.

Bioactive components of caper (Capparis spinosa L.) from Sicily and antioxidant effects in a red meat simulated gastric digestion

An increasing body of evidence on the association between adherence to the Mediterranean diet and healthy status is being accumulated. Floral buds of Capparis spinosa L. are commonly used in the Mediterranean cuisine as flavoring for meat and other foods. The present study evaluated bioactive components and antioxidant activity of Sicilian capers stabilized in salt. Whereas alpha-tocopherol was absent, low levels of gamma-tocopherol and vitamin C were measured. With reference to one serving size (8.6 g of capers), rutin was 13.76 mg, isothiocyanates, recently acknowledged as anticarcinogen phytochemicals, were 42.14 micromol, total phenols were 4.19 mg of gallic acid equivalents (GAE), and the total antioxidant potential measured using the [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)] diammonium salt (ABTS) cation radical decolorization assay was 25.8 micromol of Trolox equivalents. The antioxidative activity of a caper hydrophilic extract was assessed in a number of assays. The extract at 3.5 and 7.0 microM GAE exhibited a dose-dependent peroxyl radical scavenging activity in a methyl linoleate methanol solution oxidized by azo initiator, and reduced hypervalent iron myoglobin species formed from met-Mb an H 2O 2, at 180 microM GAE. The hydrophilic extract, at 70-280 microM GAE, caused a dose-dependent inhibition of lipid autoxidation in heated red meat, incubated with simulated gastric fluid for 180 min. In the same model rutin tested at a concentration corresponding to its content in the extract was ineffective, and alpha-tocopherol at 25 microM was poorly effective. The hydrophilic extract (70 microM GAE) prevented the consumption of the co-incubated alpha-tocopherol, whereas lipid oxidation was inhibited for the experimental time, suggesting cooperative interactions between extract components and the vitamin. The findings encourage the use of caper with foods that contribute oxidizable lipids in view of the association between dietary oxidized lipids and risk of oxidative stress-based diseases.

Diverse hepatitis C virus glycoproteins mediate viral infection in a CD81-dependent manner

We recently reported that retroviral pseudotypes bearing the hepatitis C virus (HCV) strain H and Con1 glycoproteins, genotype 1a and 1b, respectively, require CD81 as a coreceptor for virus-cell entry and infection. Soluble truncated E2 cloned from a number of diverse HCV genotypes fail to interact with CD81, suggesting that viruses of diverse origin may utilize different receptors and display altered cell tropism. We have used the pseudotyping system to study the tropism of viruses bearing diverse HCV glycoproteins. Viruses bearing these glycoproteins showed a 150-fold range in infectivity for hepatoma cells and failed to infect lymphoid cells. The level of glycoprotein incorporation into particles varied considerably between strains, generally reflecting the E2 expression level within transfected cells. However, differences in glycoprotein incorporation were not associated with virus infectivity, suggesting that infectivity is not limited by the absolute level of glycoprotein. All HCV pseudotypes failed to infect HepG2 cells and yet infected the same cells after transduction to express human CD81, confirming the critical role of CD81 in HCV infection. Interestingly, these HCV pseudotypes differed in their ability to infect HepG2 cells expressing a panel of CD81 variants, suggesting subtle differences in the interaction of CD81 residues with diverse viral glycoproteins. Our current model of HCV infection suggests that CD81, together with additional unknown liver specific receptor(s), mediate the virus-cell entry process.

Increased resistance to oxidation of betalain-enriched human low density lipoproteins

Betalains are natural pigments recently considered as compounds with potential antioxidative properties. In this work, ex vivo plasma spiking of pure either betanin or indicaxanthin, followed by isolation of low density lipoprotein (LDL), and measurement of its resistance to copper-induced oxidation, has been used to research if these betalains can bind to LDL and prevent oxidation of LDL lipids. When pooled human plasma from 10 healthy volunteers was incubated in the presence of 25-100 microM either betanin or indicaxanthin, incorporation of both compounds in LDL was observed, with a maximum binding of 0.52 +/- 0.08, and 0.51 +/- 0.06 nmoles of indicaxanthin and betanin, respectively, per mg LDL protein. Indicaxanthin-enriched and betanin-enriched LDL were more resistant than homologous native LDL to copper-induced oxidation, as assessed by the elongation of the induction period. The incorporated indicaxanthin, however, appeared twice as effective as betanin in increasing the length of the lag phase, while both compounds did not affect the propagation rate. Both betalains were consumed during the inhibition period of lipid oxidation, and delayed consumption of LDL-beta carotene. Indicaxanthin, but not betanin, prevented vitamin E consumption at the beginning of LDL oxidation, and prolonged the time of its utilization. The resistance of LDL to oxidation when vitamin E and indicaxanthin acted separately in a sequence, was lower than that measured when they were allowed to act in combination, indicating some synergistic interaction between the two molecules. No prooxidant effect over a large concentration range of either betanin or indicaxanthin was observed, when either betalain was added to the LDL system undergoing a copper-induced oxidation. These results show than indicaxanthin and betanin may bind to LDL, and are highly effective in preventing copper-induced lipid oxidation. Interaction with vitamin E appears to add a remarkable potential to indicaxanthin in the protection of LDL. Although molecular mechanisms remain uncompletely understood, various aspects of the action of betanin and indicaxanthin in preventing LDL lipid oxidation are discussed.

Evidence for heterogeneous forms of the snake venom metalloproteinase jararhagin: a factor contributing to snake venom variability

The reprolysin subfamily of metalloproteinases includes snake venom metalloproteinases (SVMP) and mammalian disintegrin/metalloproteinase. These proteins are synthesized as zymogens and undergo proteolytic processing resulting in a variety of multifunctional proteins. Jararhagin is a P-III SVMP isolated from the venom of Bothrops jararaca. In crude venom, two forms of jararhagin are typically found, full-length jararhagin and jararhagin-C, a proteolytically processed form of jararhagin that is composed of the disintegrin-like and cysteine-rich domains of jararhagin. To better understand the structural and mechanistic bases for these forms of jararhagin in the venom of B. jararaca and the source of venom complexity in general, we have examined the jararhagin forms isolated from venom and the autolysis of isolated jararhagin under the conditions of varying pH, calcium ion concentration, and reducing agents. From our results, jararhagin isolated from venom appears as two forms: a predominant form that is stable to in vitro autolysis and a minor form that is susceptible to autolysis under a variety of conditions including alkaline pH, low calcium ion concentrations, or reducing agent. The autolysis site for production of jararhagin-C from isolated jararhagin was different from that observed for jararhagin-C as isolated from crude venom. Taken together, these data lead us to the conclusion that during the biosynthesis of jararhagin in the venom gland at least three forms are present: one form which is rapidly processed to give rise to jararhagin-C, one form which is resistant to processing in the venom and autolysis in vitro, and one minor form which is susceptible to autolysis under conditions that promote destabilization of its structure. The presence of these different forms of jararhagin contributes to greater structural and functional complexity of the venom and may be a common feature among all snake venoms. The biological and biochemical features in the venom gland responsible for these jararhagin isoforms are currently under investigation.

Reaction of melatonin with hemoglobin-derived oxoferryl radicals and inhibition of the hydroperoxide-induced hemoglobin denaturation in red blood cells

Melatonin has been shown to act as a radical scavenger in various chemical and biological model systems in vitro. Kinetic evidence is now provided showing that melatonin inhibits the irreversible degradation of hemoglobin (Hb), when incubated with red blood cells exposed to the oxidant activity of cumene hydroperoxide (cumOOH). A decrease of heme loss and accumulation of soluble methemoglobin (met-Hb) are explained in terms of the interaction of the indoleamine with perferryl Hb (Hb[Fe(IV)=O]), a highly reactive Hb-derived radical species responsible for the irreversible Hb degradation. A kinetic study, in pure chemical solution, showed that melatonin can effectively reduce the oxoferryl heme group of perferryl-Hb, thus forming met-Hb. The reducing activity of melatonin is of the same order as that of Trolox, the water-soluble vitamin E analog. This novel radical-scavenging activity of melatonin may contribute to the previously observed protective effects of melatonin in ischemia-reperfusion injury.

A novel autocrine pathway of tumor escape from immune recognition: melanoma cell lines produce a soluble protein that diminishes expression of the gene encoding the melanocyte lineage melan-A/MART-1 antigen through down-modulation of its promoter

We have observed that malignant melanoma cells produce a soluble protein factor(s), which down-regulates melanocyte lineage Melan-A/MART-1 Ag expression by melanoma cells with concomitant loss of recognition by Melan-A/MART-1-specific T cells. This down-modulation of Melan-A/MART-1 expression, which we refer to as "Ag silencing," is mediated via its minimal promoter, whereas the promoter for the restricting Ag-presenting HLA-A2 molecule is not affected. Significantly, this Ag silencing is reversible, as removal of factor-containing supernatants from Melan-A/MART-1-expressing cells results in up-regulation of the promoter for the gene encoding this Ag, and renewed expression of the protein. We have evaluated over 20 known factors, none of which accounts for the Ag-silencing activity of the melanoma cell culture supernatants. The existence of this autocrine pathway provides an additional novel explanation for melanoma tumor progression in vivo in the presence of CTL specific for this melanocyte lineage Ag. These observations may have important implications for Melan-A/MART-1-specific CTL-mediated immunotherapy of melanoma tumors.

Oral supplements of vitamin E improve measures of oxidative stress in plasma and reduce oxidative damage to LDL and erythrocytes in beta-thalassemia intermedia patients

Fifteen beta-thalassemia intermedia patients, not requiring chronic transfusional therapy, were monitored in order to check their antioxidant status, and the lipid oxidation products in plasma, LDL, and erythrocytes before and during a 9-month oral treatment with 600 mg/day vitamin E. The low level of vitamin E, and high level of malondialdehyde in plasma clearly tended to normalize after three months (P < .001), and were quite similar to control after six months. The abnormally low level of vitamin E in LDL and the four times higher than control basal level of conjugated dienes (LDL-CD), were not modified after three months of treatment. Significant changes of LDL-VE (P < .05) and of the basal LDL-CD (P < .001) were evident after six months. LDL-VE was within the normal range after nine months, whereas LDL-CD still appeared twice as higher than control. Plasma vitamin A, ascorbate, beta-carotene, and lycopene increased markedly at the end of the trial (P < .005). The level of vitamin E in red blood cells was normalized after six months of supplementation. A decrease of the baseline value of conjugated dienes was observed after nine months, although it remained 1.4-fold higher than control. The RBC count and hematocrit appeared higher at the end of the trial (P < .05 and P < .001, respectively). The hemoglobin value did not show variations. A shift to normal of the resistance of erythrocytes to osmotic lysis was observed. Our findings provide evidence that an oral treatment with vitamin E improves the antioxidant/oxidant balance in plasma, LDL particles, and red blood cells, and counteracts lipid peroxidation processes in beta-thalassemia intermedia patients.