Galectin-1 binds oncogenic H-Ras to mediate Ras membrane anchorage and cell transformation

Ras genes, frequently mutated in human tumors, promote malignant transformation. Ras transformation requires membrane anchorage, which is promoted by Ras farnesylcysteine carboxymethylester and by a second signal. Previously we showed that the farnesylcysteine mimetic, farnesylthiosalicylic acid (FTS) disrupts Ras membrane anchorage. To understand how this disruption contributes to inhibition of cell transformation we searched for new Ras-interacting proteins and identified galectin-1, a lectin implicated in human tumors, as a selective binding partner of oncogenic H-Ras(12V). The observed size of H-Ras(12V)-galectin-1 complex, which is equal to the sum of the molecular weights of Ras and galectin-1 indicates a direct binding interaction between the two proteins. FTS disrupted H-Ras(12V)-galectin-1 interactions. Overexpression of galectin-1 increased membrane-associated Ras, Ras-GTP, and active ERK resulting in cell transformation, which was blocked by dominant negative Ras. Galectin-1 antisense RNA inhibited transformation by H-Ras(12V) and abolished membrane anchorage of green fluorescent protein (GFP)-H-Ras(12V) but not of GFP-H-Ras wild-type (wt), GFP-K-Ras(12V), or GFP-N-Ras(13V). H-Ras(12V)-galectin-1 interactions establish an essential link between two proteins associated with cell transformation and human malignancies that can be exploited to selectively target oncogenic Ras proteins.

Patterns of protein kinase C isoenzyme expression in transitional cell carcinoma of bladder. Relation to degree of malignancy

We determined the pattern of protein kinase C (PKC) isoform expression in human cell lines by Western blotting and immunofluorescent staining techniques. In addition, we examined PKC isoform expression in tissue samples of transitional cell carcinoma (TCC) of the bladder. PKC delta, PKC beta II, and PKC eta were found primarily in the RT4 cell line (low-grade tumor), and PKC zeta was expressed most strongly in the SUP cell line (invasive tumor). In tissue samples of urinary bladder cancer, PKC isoenzymes were expressed differentially as a function of tumor stage and grade; expression of PKC beta II and PKC delta was high in normal tissue and in low-grade tumors and decreased with increasing stage and grade of TCC. The opposite pattern was seen with PKC zeta. The differences in expression of specific isoenzymes as related to levels of malignancy of the cell lines and tissue samples suggest that the PKC family has an important role in normal and neoplastic urothelium.

Psychiatric problems in returning travelers: features and associations

BACKGROUND

Travelers may return from the tropics with psychological problems. The literature regarding features and associations of these psychological problems is limited.

METHODS

Case histories of 15 consecutive returning travelers seen at our psychiatric service during the last 8 years.

RESULTS

The median age of this group was 25 years, 10 were males, and the length of trip ranged from 10 days to 8.5 months. None of these travelers had prior psychopathology. The most common presentation was anxiety (with or without depression, n = 11), 3 suffered from acute psychosis, and 1 had pure depression. Eight of the travelers have used illicit drugs, which in 5 cases probably served as a trigger. Antimalarials may have played a role in 3 travelers. Six travelers needed antidepressants and supportive therapy, 3 neuroleptics, and 1 psychotherapy. These treatments lasted for 6 months and over in 6 of the travelers.

CONCLUSION

Psychiatric problems among travelers to the tropics are multifarious in nature, multifactorial, have a strong relation to drug abuse, and may require a long and intensive therapy. Travelers should be better educated about the risks of using illicit drugs.

Dynamics of the antibody response in cattle infested by Hypoderma (Diptera: Oestridae) after a treatment with injectable and pour-on ivermectin

The dynamics of the anti-Hypoderma antibody response after a treatment with injectable and pour-on ivermectin against first instars of Hypoderma sp. were determined in naturally infested cows. Cattle were randomly assigned to three groups: group 1, which served as an untreated control; group 2, treated with pour-on ivermectin at a dose of 500 microg/kg of body weight, and group 3, which received 200 microg/kg of body weight of ivermectin by subcutaneous injection. Both ivermectins showed total efficacy against L-1 of Hypoderma sp. In untreated control animals, grubs became detectable in the 2 mo after treatment. Indirect enzyme-linked immunosorbent assay (ELISA) showed a significant increase in group 3 antibody levels 1 mo after treatment, whereas in group 2 the increase was not significant. Following the peak of anitibody activity in group 3, antibody levels declined at a faster rate than in those treated topically. In both treated groups, cattle remained serologically positive for 4 mo after ivermectin treatment. Thus, serological surveillance programs for cattle grubs conducted during this posttreatment period will not be influenced by treatment with ivermectin. The persistence of antibody levels after larval destruction makes the indirect ELISA unsuitable for the prediction of the efficacy of treatment.

Optimization of nucleated red blood cell (NRBC) recovery from maternal blood collected using both layers of a double density gradient

The isolation of fetal nucleated red blood cells (NRBC) from maternal blood represents a promising approach to non-invasive prenatal diagnosis. However, the number of fetal NRBC in maternal circulation is quite low and therefore difficult to isolate. An enrichment procedure in which both layers from a double density 1.077/1.107 g/ml gradient are collected was optimized, followed by MACS selection using non-commercial monoclonal antibodies. The influence of the delay in processing maternal blood on the NRBC distribution in both interfaces of the gradient was also studied in cord blood and peripheral maternal blood samples. A significant increase in the number of NRBC isolated from maternal blood was achieved by collecting both layers of the double density gradient compared with the previous protocol in which only the lower layer was recovered. Cord blood samples showed significant differences in the number of NRBC recovered when processed at 24 instead of within 3 h. This effect was also observed in the number of NRBC collected only from the upper layer of peripheral maternal blood samples. Therefore, in order to minimize the target cell losses, it is advisable to process the maternal blood samples as soon as possible.

99mTc-MIBI scintigraphy of parathyroid adenomas and its relation to tumour size and oxyphil cell abundance

The aim of this study was to assess the correlation between technetium-99m methoxyisobutylisonitrile (MIBI) uptake by parathyroid adenomas, oxyphil cell content and volume of the lesions. Thirty-one patients with parathyroid adenomas were evaluated prospectively. Preoperative double-phase 99mTc-MIBI scintigraphy was performed in all patients and tracer uptake by parathyroid lesions was assessed semi-quantitatively employing region of interest ratios to normal adjacent neck areas. Surgical specimens underwent histological evaluation and oxyphil cell content was determined. The intensity of tracer uptake was compared with oxyphil cell content, volume of the lesions and serum levels of calcium and parathormone. 99mTc-MIBI tracer uptake was correlated with oxyphil cell content, volume of parathyroid lesions and the functional status of the parathyroid adenomas. Tracer accumulation in oxyphil cells might partially explain the preferential 99mTc-MIBI retention in parathyroid lesions.

Nonhepatosplenic gamma delta T-cell lymphoma with initial testicular compromise

We report here a case of nonhepatosplenic gammadelta T-cell lymphoma with undescribed initial localization in testis, without hepatosplenomegaly or adenopathies, and subsequent development in the maxillary sinus. The maxillar mass biopsy revealed a T-cell infiltration, and its immunologic characterization by flow cytometry showed a gammadelta T-cell phenotype (CD45+, CD3+, CD2+, TCR gammadelta+), without expression of CD7, CD5, CD1a, TdT, CD4, CD8, TCR alphabeta, or NK antigens (CD16, CD56, and CD57). Clonal gamma-chain gene rearrangement by polymerase chain reaction (PCR) was detected in testicular and maxillar biopsies. Epstein-Barr virus type 1 (EBV) sequences were detected by molecular biology in the biopsy material, suggesting that this oncogenic virus may play a role in the genesis of the clonal expansion of gammadelta T-cells. The patient was initially treated with standard chemotherapeutic protocols, with poor response and aggressive course.

Protein kinase C (PKC) isoenzymes immunohistochemistry in lymph node revealing solution-fixed, paraffin-embedded bladder tumors

Protein kinase C (PKC) plays an important role in cellular differentiation and in the malignant process. In an earlier study, it was shown that the expression pattern of PKC isoenzymes is altered in some tumors compared to their corresponding normal tissue. In this study, we evaluated the pattern of PKC isoenzyme immunostaining in bladder transitional cell carcinoma (TCC) of different grades and stages and normal tissue. Twenty-seven TCC samples and six areas of normal bladder mucosa were stained with antibodies specific for the PKC isoenzymes: alpha, beta 1, beta 2, delta, and zeta. The sections were scored for intensity of staining, and the correlation with grade and stage of the tumors was computed. The PKC alpha and beta 2 immunostains were intense in normal urothelium and in all evaluated tumors. PKC beta 1 and delta stains were intense in normal and low-grade and -stage tumors and weak in high-grade and -stage tumors. The opposite trend was found for PKC zeta. PKC isoenzyme expression differs in invasive TCC compared to low-grade, low-stage TCC and normal urothelium. The value of these findings as a marker of tumor aggressiveness should be further assessed.

The value of early and double phase 99Tcm-sestamibi scintimammography in the diagnosis of breast cancer

The aim of this study was to assess the additional value of early and double phase scintimammography (SMM) with 99Tcm-sestamibi in the detection of breast cancer following initial evaluation by palpation and mammography. Altogether, 322 women with breast lesions evaluated prospectively by palpation, fine-needle aspiration and mammography were assigned a malignancy risk according to the results. Scintimammography was performed in all patients in the prone breast dependent position. Immediate and delayed views were obtained. Acquisition of immediate tracer uptake was termed 'early phase' SMM, whereas a combination of both immediate and delayed phase images was termed 'double phase' SMM. All patients underwent breast biopsy. Both early phase and double phase SMM detected eight of nine tumours in the low-risk group (88.8% sensitivity). In the uncertain cases (moderate-risk group), early phase SMM detected all malignant tumours, but double phase SMM missed one (92.3% sensitivity). In the high-risk group, early phase SMM missed two breast cancers (94.6% sensitivity) and double phase SMM missed four (89.2% sensitivity). Overall, early phase SMM had a sensitivity of 94.9% and a specificity of 80.2% in detecting breast cancer, whereas double phase SMM had a sensitivity of 89.8% and a specificity of 94.3%. Both methods had 100% sensitivity for tumours larger than 1 cm. In conclusion, SMM detected additional breast cancers following an initial evaluation by palpation, fine-needle aspiration and mammography. Our results suggest that double phase SMM is more specific than early phase SMM, although early phase SMM is more sensitive. Whether the interpretation of SMM results should rely on both early and delayed images, or early images alone, should be based on the relative risk of malignancy of the breast lesion as estimated by the initial evaluation.

Novel breast-tumor-associated MUC1-derived peptides: characterization in Db-/- x beta2 microglobulin (beta2m) null mice transgenic for a chimeric HLA-A2.1/Db-beta2 microglobulin single chain

The MUC1 protein was found to be up-regulated in a spectrum of malignant tumors. T-cell responses to the MUC1 extracellular tandem repeat array (TRA) were observed in murine models as well as in breast-carcinoma patients. In the present study, we evaluated the anti-tumor potential of HLA-A2.1-motif-selected peptides from non-TRA domains of the molecule. Peptide immunogenicity was examined in the Db-/- x beta2 microglobulin (beta2m) null mice transgenic for a modified HLA-A2.1/Db-beta2 microglobulin single chain (HHD mice). Our results show the existence of 3 novel HLA-A2.1-restricted MUC1-derived cytotoxic T-lymphocyte (CTL) epitopes. These peptides are processed and presented by the HHD-transfected breast-tumor cell line MDA-MB-157. Moreover, CTL induced by these 3 peptides show higher lysis of target cells pulsed with breast-carcinoma-derived peptides than of targets pulsed with normal breast-tissue-derived peptides. These data suggest an important role for non-TRA MUC1-derived peptides as inducers of a MHC-restricted CTL reaction to a breast-carcinoma cell line and patient-derived tumor extracts.

Influence of internal and environmental factors on the distribution and occurrence of Hypoderma (Diptera: Oestridae) in cattle in Galicia (northwest of Spain)

This study establishes the seroprevalence of Hypoderma spp in cattle and the influence of some internal and environmental factors in the distribution of this myiasis in Galicia (northwest of Spain). Humoral antibody levels were measured by means of an indirect enzyme-linked immunosorbet assay, using as the antigen hypodermin C obtained from 1st-instar Hypoderma lineatum (De Villers). The percentage of positive sera in the total sample of 1,473 animals was 78.4%. Considering the different climatic areas in Galicia, the seroprevalence was lower in coastal areas; whereas, in the inland the percentages of positive sera were higher. The study revealed significant differences in seroprevalence between breeds; the autochthonous Rubia Gallega breed was the most prevalent, followed by the crossbreeds Brown Swiss and Friesian. The breeding system was an important factor affecting the occurrence of hypodermosis.

Assessment of a recombinant antigen versus natural hypodermin C for the serodiagnosis of hypodermosis in cattle

An indirect ELISA test using as antigen a recombinant parasite protein, hypodermin C, was developed to measure Hypoderma-specific antibodies in cattle sera and compared with natural hypodermin C. To evaluate the field efficacy of the ELISA test, 334 serum samples were collected from cows raised at farms in Galicia for a serological survey. Compared with an ELISA based on natural parasite antigen, the recombinant hypodermin C gave excellent results, with a sensitivity of 95.8% and a specificity of 95.7%. Considering the cut-off point, with the recombinant hypodermin C, 70.9% of the animals had positive levels of antibodies to Hypoderma and with natural hypodermin C, 73.6%. Recombinant hypodermin C appears to be a useful alternative to the natural parasite antigen for the serodiagnosis of Hypoderma sp in cattle.

Targeting of K-Ras 4B by S-trans,trans-farnesyl thiosalicylic acid

Ras proteins regulate cell growth, differentiation and apoptosis. Their activities depend on their anchorage to the inner surface of the plasma membrane, which is promoted by their common carboxy-terminal S-farnesylcysteine and either a stretch of lysine residues (K-Ras 4B) or S-palmitoyl moieties (H-Ras, N-Ras and K-Ras 4A). We previously demonstrated dislodgment of H-Ras from EJ cell membranes by S-trans,trans-farnesylthiosalicylic acid (FTS), and proposed that FTS disrupts the interactions between the S-prenyl moiety of Ras and the membrane anchorage domains. In support of this hypothesis, we now show that FTS, which is not a farnesyltransferase inhibitor, inhibits growth of NIH3T3 cells transformed by the non-palmitoylated K-Ras 4B(12V) or by its farnesylated, but unmethylated, K-Ras 4B(12) CVYM mutant. The growth-inhibitory effects of FTS followed the dislodgment and accelerated degradation of K-Ras 4B(12V), leading in turn to a decrease in its amount in the cells and inhibition of MAPK activity. FTS did not affect the rate of degradation of the K-Ras 4B, SVIM mutant which is not modified post-translationally, suggesting that only farnesylated Ras isoforms are substrates for facilitated degradation. The putative Ras-recognition sites (within domains in the cell membrane) appear to tolerate both C(15) and C(20) S-prenyl moeities, since geranylgeranyl thiosalicylic acid mimicked the growth-inhibitory effects of FTS in K-Ras 4B(12V)-transformed cells and FTS inhibited the growth of cells transformed by the geranylgeranylated K-Ras 4B(12V) CVIL isoform. The results suggest that FTS acts as a domain-targeted compound that disrupts Ras-membrane interactions. The fact that FTS can target K-Ras 4B(12V), which is insensitive to inhibition by farnesyltransfarase inhibitors, suggests that FTS may target Ras (and other prenylated proteins important for transformed cell growth) in an efficient manner that speaks well for its potential as an anticancer therapeutic agent.

Development, characterization, and use of monoclonal antibodies made to antigens expressed on the surface of fetal nucleated red blood cells

BACKGROUND

Current methods for obtaining fetal cells for prenatal diagnosis are invasive and carry a small (0.5-1.0%) but definite risk of miscarriage. An attractive alternative would be isolation of fetal cells from peripheral maternal blood using antibodies with high specificity and avidity.

METHODS

To generate antibodies, we purified nucleated red blood cells (NRBCs) from fetal livers and used them as the immunogen to generate monoclonal antibodies (mAbs) directed against surface antigens.

RESULTS

The four antibodies recognized at least two conformationally sensitive epitopes of the transferrin receptor. Isolation of NRBCs from 252 maternal blood samples using these antibodies in magnetic activated cell sorting after an initial density gradient centrifugation yielded 0-419 NRBCs per 25 mL of maternal blood. One antibody, 2B7.4, not only isolated the highest number of NRBCs (>10 in 90% of the samples) but also isolated these NRBCs in 78 consecutive maternal samples.

CONCLUSION

Antibody 2B7.4 shows promise for the isolation of NRBCs from maternal blood and should allow studies concerning the source of these cells, fetal vs maternal, and the factors controlling their prevalence.

Subclass profile of specific IgG antibodies in rats challenged during acute and chronic primary infection with Fasciola hepatica

The influence of a previous infection (acute and chronic) on the kinetics of the immune humoral response in rats challenged with Fasciola hepatica was studied. Two infected groups were reinfected at different times--one, at 4 weeks after primary infection (w.a.p.i.); and the other, at 11 w.a.p.i. Signs of reinfection were observed in the two challenged groups as evidenced by an increment in glutamate dehydrogenase and gamma-glutamyl transpeptidase activity after secondary infection. IgG subclass (IgG1, IgG2a, IgG2b, IgG2c) responses to F. hepatica excretory/secretory products (FhESP) differed, depending on the time of challenge infection, but no difference was observed between the reinfected groups. A predominance of the IgG1 subclass was noted in the group challenged at 4 w.a.p.i., and IgG2b and IgG2c were prominent in the group reinfected at 11 w.a.p.i. These results indicate that the presence of juvenile or adult flukes in the liver at the time of challenge seems to influence the immune response to a secondary infection.

Molecular cloning and structural and functional characterization of human cathepsin F, a new cysteine proteinase of the papain family with a long propeptide domain

A cDNA encoding a new cysteine proteinase belonging to the papain family and called cathepsin F has been cloned from a human prostate cDNA library. This cDNA encodes a polypeptide of 484 amino acids, with the same domain organization as other cysteine proteinases, including a hydrophobic signal sequence, a prodomain, and a catalytic region. However, this propeptide domain is unusually long and distinguishes cathepsin F from other proteinases of the papain family. Cathepsin F also shows all structural motifs characteristic of these proteinases, including the essential cysteine residue of the active site. Consistent with these structural features, cathepsin F produced in Escherichia coli as a fusion protein with glutathione S-transferase degrades the synthetic peptide benzyloxycarbonyl-Phe-Arg-7-amido-4-methylcoumarin, a substrate commonly used for functional characterization of cysteine proteinases. Furthermore, this proteolytic activity is blocked by trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane, an inhibitor of cysteine proteinases. The gene encoding cathepsin F maps to chromosome 11q13, close to that encoding cathepsin W. Cathepsin F is widely expressed in human tissues, suggesting a role in normal protein catabolism. Northern blot analysis also revealed a significant level of expression in some cancer cell lines opening the possibility that this enzyme could be involved in degradative processes occurring during tumor progression.

Twenty-four-hour oscillations of facial electroneurography parameters and their relationship to body temperature

The purpose of the present study was to assess the temporal variation of the facial electroneurography (ENoG) parameters recorded from the nasolabial crease and to compare it to the temporal oscillations of oral and facial cutaneous temperatures. Twelve healthy individuals were examined at 4-hour intervals for 2 consecutive days. Twenty-four-hour rhythms of oral and facial cutaneous temperatures were found in all subjects (troughs on average at 4:20 and 4:00 AM, respectively). Significant 24-hour oscillations of ENoG amplitude were found in all subjects, which were positively correlated to the oscillations of oral and facial cutaneous temperatures (trough on average at 2:40 AM). The compound action potential (CAP) latency fluctuated during the day and was negatively correlated with local temperatures. However, these fluctuations and correlations did not reach statistical significance. We also found a significant reduction of ENoG amplitude in 5 patients with artificial cooling of the face near the facial nerve. Also, there was a small increase in CAP latency with facial cooling. Interpreting ENoG recordings in accordance with oral temperature and recording time of day reduce the intertest variation.

Lymph node revealing solution: a rapid method for the fixation of cystectomy specimens

The objective of this study was to describe the use of the lymph node revealing solution (LNRS) for rapid fixation of total cystectomy specimens, and to compare it with formalin fixation. LNRS is a mixture of 95% ethanol, diethyl ether, glacial acetic acid and buffered formalin (65:20:5:10 v/v) prepared under a fume-hood. Sixteen consecutive cystectomy specimens were fixed for two hours either in LNRS or in buffered formalin. Representative sections were embedded in paraffin, sectioned and stained with H&E, periodic acid Schiff, alcian-blue, and immunostained for cytokeratins 20, high and low molecular weight cytokeratins, prostatic specific antigen, Factor VIII related antigen, s-100 protein, and protein kinase C isoenzymes. Results showed that the tissues were well fixed after 2 hours in LNRS, and were not fixed after 2 hours in formalin. Processing and sectioning of the paraffin blocks of the LNRS fixed tissue was excellent; it was impossible in the sections fixed for 2 hours in formalin. All the stains were excellent after LNRS fixation. We conclude that fixation of cystectomy specimens in LNRS requires only two hours and results in excellent stained slides. It is therefore recommended for cystectomy specimens.

Double-phase 99mTc-sestamibi scintimammography and trans-scan in diagnosing breast cancer

The goal of our study was to assess the value of both scintimammography with 99mTc-sestamibi (SMM) and trans-scan (T-scan) in detecting breast cancer.

METHODS

A total of 121 women were evaluated by palpation, mammography, SMM and T-scan. SMM was performed in the prone, breast dependent position. Immediate and delayed views (double-phase) were obtained. T-scan is a new breast imaging method that maps noninvasively the distribution of tissue electrical impedance and capacitance.

RESULTS

SMM had 88.9% sensitivity, 88.4% specificity and 88.4% accuracy in detecting breast cancer. SMM had 100% sensitivity in detecting breast tumors >1 cm and only 66% sensitivity in detecting tumors <1 cm. T-scan had 72.2% sensitivity and 67% specificity in detecting breast cancer. It detected one more breast cancer than SMM, at the expense of 27 additional false-positive results.

CONCLUSION

Double-phase SMM was sensitive and specific in detecting breast cancer. This method may reduce the rate of negative breast biopsies in tumors >1 cm. T-scan was only moderately accurate in detecting breast cancer. Its addition to SMM did not improve significantly the rate of breast cancer detection. However, because of its complete noninvasiveness, large-scale applicability and low cost, T-scan deserves further refining.

IgG isotype specific immune response in rats infected with Fasciola hepatica

Antibody responses (IgG1, IgG2a, IgG2b, and IgG2c subclasses) against Fasciola hepatica L. in rats infected with metacercariae were analysed by ELISA. Animals of group 1 (R-1) remained infected throughout 21 weeks, and rats of group 2 (R-2) received a single oral dose of triclabendazole (Fasinex 10%, Ciba-Geigy) at 4 weeks after infection. Group C (R-C) consisted of rats left intact which served as uninfected controls. All IgG subclasses increased during the first weeks after infection, but when triclabendazole was administered IgG1 and IgG2b diminished markedly. IgG2c showed a different profile to the other antibodies evaluated, increasing earliest and decreasing profoundly from the 9-11th week after infection (w.a.i). The infected-untreated rats produced higher titres of antibodies than the rats of R-2, and these differences were statistically significant (p < 0.05) in all subclasses evaluated except in IgG2a titres.

Nucleolar organizer regions in conjunctival nevi and melanomata

The objective of this study was to compare the argyrophil nucleolar organizer region (Ag-NOR) counts of conjunctival nevi and melanomata and to compare the efficacy of this method in their differential diagnosis. Nine histologically diagnosed conjunctival nevi and three conjunctival malignant melanomas were studied. Representative sections were stained using the AgNOR technique. Fifty cells of each melanocytic lesion were randomly selected without knowing their histologic diagnosis. The AgNORs were visualized at a magnification of x1000. They consisted of clusters >1 micron in diameter and of satellites <1 micron in diameter, which were counted and recorded for each cell separately. The mean AgNOR count for the nevi was 1.12 clusters and 1.72 satellites per cell, while the count for the melanomas was 1.6 clusters and 6.8 satellites per cell. These results are statistically significant. There was no overlap between the number of AgNOR clusters and satellites in conjunctival nevi and melanomas, indicating that the AgNOR count might be a useful tool in distinguishing benign from malignant conjunctival melanocytic lesions.