An alternatively spliced form of CD79b gene may account for altered B-cell receptor expression in B-chronic lymphocytic leukemia

Several functional anomalies of B-chronic lymphocytic leukemia (B-CLL) cells may be explained by abnormalities of the B-cell receptor (BCR), a multimeric complex formed by the sIg homodimer and the noncovalently bound heterodimer Igalpha/Igbeta (CD79a/CD79b). Because the expression of the extracellular Ig-like domain of CD79b has been reported to be absent in the cells of most CLL cases, we have investigated the molecular mechanisms that may account for this defect. Peripheral blood lymphocytes (PBL) from 50 patients and two cell lines (MEC1, MEC2) obtained from the PBL of one of them were studied. MEC1, MEC2, and 75% of CLL cases did not express detectable levels of the extracellular Ig-like domain of CD79b, which was nevertheless present in greater than 80% CD19(+) cells from normal donors. In healthy subjects the expression of CD79b was equally distributed in CD5(+) and CD5(-) B-cell subsets. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of CD79b RNA from all patients and from MEC1 and MEC2 cell lines consistently yielded two fragments of different size (709 bp and 397 bp). The 709-bp band corresponds to CD79b entire transcript; the 397-bp band corresponds to an alternatively spliced form lacking exon 3 that encodes the extracellular Ig-like domain. Both fragments were also visible in normal PBL. The expression of the 397-bp fragment was increased in normal activated B cells, while no difference was seen between CD5(+) and CD5(-) B cells. To obtain a more accurate estimate of the relative proportions of the two spliced forms, a radioactive PCR was performed in 13 normal and 22 B-CLL samples and the results analyzed using a digital imager. The mean value of the CD79b to the CD79b internally deleted ratio was 0.64 +/- 0.20 SD in normal donors and 0.44 +/- 0.27 SD in B-CLL (P =.01). Direct sequencing of 397-bp RT-PCR products and of genomic DNA corresponding to exon 3 from MEC1, MEC2, their parental cells, and five fresh B-CLL samples did not show any causal mutation. Single-strand conformation polymorphism analysis of exon 3 performed in 18 additional B-CLL cases showed a single abnormal shift corresponding to a TGT --> TGC polymorphic change at amino acid 122. We propose a role for the alternative splicing of CD79b gene in causing the reduced expression of BCR on the surface of B-CLL cells. As normal B cells also present this variant, the mechanism of CD79b posttranscriptional regulation might reflect the activation stage of the normal B cell from which B-CLL derives.

Frequency of a mutated CCR-5 allele (delta32) among Italian healthy donors and individuals at risk of parenteral HIV infection

The aim of this study was to assess the frequency of a truncated allele of the CCR-5 gene (delta32) in Italy, and address its possible role in parenteral HIV transmission, as well as its influence in HIV-associated disease progression. In 371 unrelated seronegative healthy blood donors the delta32 allele frequency was 0.047; this figure was significantly different from those reported in northern America and northern Europe populations. However, delta32 allele frequency in healthy individuals did not differ significantly from that found in 54 seronegative drug users (0.065), 98 seronegative hemophiliacs (0.051), and 81 seropositive hemophiliacs (0.049). Although in seropositive hemophiliacs the wt/delta32 heterozygous genotype was associated with a trend to a slower decline in CD4+ cell counts, its presence did not seem to influence disease progression, as comparable delta32 allele frequency frequencies were found among progressing (0.042) and nonprogressing (0.111) patients. These data do not seem to support a protective role of the delta32 allele in preventing HIV infection through the parenteral route, or in influencing the natural history of the disease in this particular risk category, although the delta32 heterozygous state was associated with lower plasma viremia levels. On the other hand, the finding of non-syncytium-inducing HIV strains in the majority of delta32 heterozygous seropositive patients suggests that its presence could not be a major factor in driving a switch toward more cytopathic, T-tropic HIV strains through selective pressure in coreceptor usage.

Accuracy comparison between PAPNET diagnoses and conventional diagnoses in an Italian cervical cytology laboratory

In a population-based cervical screening laboratory with a controlled workload, a retrospective PAPNET review of 1,654 Pap smears was performed. The series included a random sample of smears originally and conventionally classified as negative (no. 1,309) and unsatisfactory (no. 43), and 299 consecutive smears originally classified as abnormal. The PAPNET diagnoses and the original diagnoses were compared for accuracy. For smears with discordant classification, a majority diagnosis as obtained on manual review was used as a gold standard. The PAPNET testing showed a greater proportion of negative smears classified as unsatisfactory (3.7% vs. 0.2%; ratio, 16.7; 95% CI 12.4-22.0); a reduced proportion of ASCUS/LGSIL cases correctly identified as positive (i.e., a reduced sensitivity for such lesions) (76.3% vs. 97.9%; ratio, 0.78; 95% CI 0.66-0.91); an equal proportion (96.2%) of AGUS/HGSIL cases correctly identified as positive (i.e., an equal sensitivity for such lesions); and an equal proportion of negative smears correctly identified as such (i.e., an equal specificity). In conclusion, the PAPNET testing did not improve the diagnostic performance of the manual screening.

Differential effect on TCR:CD3 stimulation of a 90-kD glycoprotein (gp90/Mac-2BP), a member of the scavenger receptor cysteine-rich domain protein family

We studied the effects of a 90-kD glycoprotein (gp90/Mac-2BP) belonging to the scavenger receptor family, present in normal serum and at increased levels in inflammatory disease and cancer patients, on some T cell function parameters. Whereas the lymphocyte proliferative response to non-specific mitogens such as phytohaemagglutinin (PHA) and concanavalin A (Con A), but not pokeweed mitogen (PWM), was strongly reduced, probably due to the lectin-binding properties of gp90/Mac-2BP, the response to T cell receptor (TCR) agonists such as superantigens and allogeneic cells was potentiated. When lymphocytes were stimulated with different anti-TCR:CD3 MoAbs, both in soluble and solid-phase form, gp90/Mac-2BP was able to down-regulate the proliferative response to anti-CD3 MoAb, whereas the response to anti-TCR alphabeta MoAb was enhanced. A similar differential effect was observed when a MoAb against CD5 (another member of the scavenger receptor superfamily) was added to anti-CD3 or anti-TCR-stimulated cells; anti-CD5 MoAb strongly down-modulated the CD3-mediated response, whereas its presence in culture was associated with potentiation of the response to TCR alphabeta agonists. gp90/Mac-2BP was able per se to up-regulate Ca2+ levels in freshly isolated lymphocytes; moreover, its presence in culture was associated with increased Ca2+ mobilization following stimulation with anti-TCR alphabeta, but not anti-CD3 MoAb. These data indicate that gp90/Mac-2BP could be able to influence some immune responses, possibly through multiple homologous interactions with other members of the scavenger receptor family; moreover, our findings suggest that signalling through the different components of the TCR:CD3 complex may follow distinct activation pathways into the cells.

[The PAPNET system in the rescreening of negative cervical/vaginal smears. A study from the Imola cytology laboratory]

The rescreening of negative cervical/vaginal smears is one of the potential areas of utilization of the systems for computer-assisted cytology diagnosis. In the Imola cytology laboratory, a random sample of 1309 conventionally prepared smears that had been originally reported as negative was rescreened with the PAPNET System (Neuromedical Systems, Inc., Suffern, NY). Smears with a PAPNET diagnosis other than negative were further and independently evaluated by the staff of the laboratory and classified according to the majority report. The PAPNET rescreening confirmed the original negative diagnosis for 1188 smears (907.6/1000) and led to the detection of 46 ASCUS/LGSIL cases (35.1/1000) and 2 AGUS/HGSIL cases (1.5/1000). Seventy-three smears (55.8/1000) were interpreted as unsatisfactory. The majority report confirmed the original negative diagnosis for 42 (91%) of the 46 PAPNET diagnoses of ASCUS/LGSIL and 50 (68%) of the 73 smears interpreted as unsatisfactory. The 2 cases of AGUS/HGSIL diagnosed by PAPNET were confirmed. The detection rate of ASCUS/LGSIL decreased from 35.1/1000 to 3.1/1000 (rate ratio 0.09, 95% confidence interval [95% CI] 0.02-0.22). The rate of unsatisfactory smears decreased from 55.8/1000 to 17.6/1000 (rate ratio 0.31, 95% CI 0.20-0.47). The rate of negative smears increased from 907.6/1000 to 977.9/1000 (rate ratio 1.08, 95% CI 1.02-1.14). In conclusion, the PAPNET rescreening of negative smears brought about a low detection rate of severe cellular changes. Though greater, the detection rate of low grade changes was substantially and significantly reduced by the majority reports. At our laboratory, the PAPNET rescreening does not appear to improve the performance of conventional cytodiagnosis.

[Analysis of the intralaboratory diagnostic variability in the Imola cervical screening program]

The value of the assessment of intralaboratory variability as a method for quality control of cervical screening is an ill-defined one. This model has been advocated and utilized by some Authors and only indirectly addressed by others. In Italy, only occasional studies have been published. The present analysis is part of a series of studies for the evaluation and quality control of the population cervical screening programme in the area of Imola. The agreement between the 5 cytologists was tested over a series of 150 smears selected from the routine material. The data were analyzed with the k statistic and the degree and direction of discrepancies were assessed by the percent distribution of paired diagnoses. The k values for agreement between the 10 possible pairs of cytologists varied between 0.25 and 0.49 (average value, 0.37). The indexes for agreement as based on three classes ('Negative'/ASCUS + LGSIL + HGSIL/'Unsatisfactory') varied from 0.35 to 0.56 (average value, 0.46). The cytologist-specific k values (as based on five classes) ranged from 0.29 to 0.43. For the observer with the lowest specific coefficient (designated as C4), the excess disagreement was restricted to the ASCUS class and the 'Unsatisfactory' notation. In particular, C4 diagnosed more often 'Negative' smears (74% vs. 44-55%) and less frequently ASCUS (11% vs. 22-31%) and 'Unsatisfactory' smears (3% vs. 6-11%). ASCUS was the least reproducible diagnosis (k = 0.22). The evaluation of the degree and direction of the diagnostic discrepancies between the five cytologists showed that the frequency of concordant diagnoses of ASCUS was as low as 39.7%. However, the discrepancies were almost always of one degree and were directed towards the 'Negative' class. Conversely, ASCUS was associated with considerable proportions of the 'Negative' diagnoses (17.3%) and those of LGSIL (31.8%). In the occasions when one observer interpreted a smear as 'Unsatisfactory' the paired diagnoses were almost evenly distributed among 'Unsatisfactory' (49.2%) and 'Negative' (43.0%). In absolute terms, the k coefficients in this study were compatible with moderate agreement. However, they were unfavourably influenced by the modalities for smear selection. The study specimens were selected by all cytologists from the routine material over a short time period and did not include smears interpretable as showing carcinoma. A comprehensive evaluation of the diagnostic performance of C4 showed that the disagreement with other cytologists was restricted to the diagnosis of ASCUS and the 'Unsatisfactory' notation and was accounted for by a lower frequency of such reports coupled with a greater frequency of the 'Negative' diagnoses. A conservative approach to lesions of minor significance is the most likely explanation for that pattern of disagreement. Although characterized by the poorest k value, the ASCUS diagnosis proved to be generally matched with reports of minor cytology changes. This was consistent with the formal definition for ASCUS in the original Bethesda System. The observation that the ASCUS diagnosis is applied to those changes is a prerequisite for a more conservative utilization of such report. In conclusion, the study revealed important correlates of the k coefficients and provided an encouraging picture of the cytologic substrates of the diagnosis of ASCUS.

Lymphoproliferative disease in human peripheral blood mononuclear cell-injected SCID mice. IV. Differential activation of human Th1 and Th2 lymphocytes and influence of the atopic status on lymphoma development

Intraperitoneal transfer of PBMC from EBV+ donors into SCID mice leads to high human Ig levels in mouse serum and B cell lymphoproliferative disease. As these events depend on the activation of coinjected human T cells, we addressed the behavior of the Th1 and Th2 subsets in this model. Production of IFN-gamma, but not of Th2 cytokines such as IL-4, was detected in culture supernatants of PBMC stimulated in vitro with mouse splenocytes. Moreover, anti-CD3 stimulation of the human cells recovered from mice brought about IFN-gamma, but not IL-4, synthesis; on the other hand, PCR and in situ hybridization analysis of ex vivo-recovered cells disclosed the presence of mRNA for both cytokines following in vitro restimulation, thus suggesting posttranscriptional regulation of IL-4 gene expression. When SCID mice were inoculated with PBMC from atopic donors, whose Th1/Th2 profile displays an imbalance toward Th2 cells, tumor development rates were lower, and tumor latency was higher, compared with those in mice injected with PBMC from normal donors. Isotypic analysis of human Ig in mouse serum showed the exclusive presence of IFN-gamma-driven IgG subclasses; in addition, human IgE were low or undetectable in most cases. These findings indicate that following transfer into SCID mice, human Th1 lymphocytes undergo preferential activation, whereas Th2 function is down-regulated. Th1 lymphocytes probably are a major component in promoting EBV+ B cell expansion and tumor development; the individual Th1/Th2 profile could in part account for the as yet unexplained donor variability in tumor generation in this experimental model.

New therapeutic perspectives for demyelinating retrobulbar optic neuritis

In patients with demyelinating retrobulbar optic neuritis (RON), a spontaneous or corticosteroid-induced improvement is generally observed within the first month, but this is clinically insignificant in 5%-7% of patients. We report the case histories of four patients who were considered to be "non-responders" to corticosteroids because their visus remained unchanged or had improved by only 1/10 after one month from intravenous corticoid therapy begun 2-7 days after disease onset, and who were therefore subsequently administered high intravenous doses of immunoglobulin. Three of these patients completely recovered in a period of 3-9 months; the fourth showed only a partial improvement, but this was consolidated after long-term continuation of the same therapy. These cases suggest the possible efficacy of early administration of intravenous immunoglobulin in RON patients who fail to respond to cortisone therapy. As recently demonstrated in animal models, it can be hypothesised that the result is due to immuno-mediated mechanisms of action that reduce autoimmune responses in the short- and medium-term, and in the long-term favour remyelination.

The cancer registry in the monitoring of cervical screening practice: the neglected value of the Pap smear in patients diagnosed with CIN3 on biopsy

Patients diagnosed with CIN3 on biopsy without a Pap smear are an inevitable correlate of the extensive utilization of colposcopy as a basic screening test. In a series of 248 CIN3 cases diagnosed on biopsy and notified to the Romagna Cancer Registry between 1986 and 1993, we evaluated the independent association between the Pap smear result and (1) the final histology diagnosis, (2) the first choice treatment, and (3) the appropriateness of hysterectomy. The patients were grouped into the following categories: (1) no smear, ie colposcopy only (n = 40 or 16%), (2) CIN1, CIN2, LGSIL, and minor changes, (3) CIN3 and HGSIL, and (4) carcinoma. In multiple logistic regression analysis, patients without a Pap smear were used as a reference category. Patients with smears reported as CIN1-2/LGSIL or less as well as CIN3/HGSIL had a significantly lower probability of invasive squamous carcinoma (odds ratio = 0.26 for both categories) compared with those not undergoing cytology. The Pap smear result was not a determinant of the first choice treatment. Hysterectomy had a greater probability of being unnecessary if performed in patients with smears reported as showing CIN3/HGSIL (odds ratio = 5.05) or less. In conclusion, this registry-based study demonstrated that the Pap smear had an independent but neglected value in the assessment of cases reported as CIN3 on colposcopy-guided biopsy.

Pseudotyping of Moloney leukemia virus-based retroviral vectors with simian immunodeficiency virus envelope leads to targeted infection of human CD4+ lymphoid cells

In view of our recent findings that a truncated form of the envelope (Env) glycoprotein of human immunodeficiency virus type 1 (HIV-1) was efficiently incorporated into MoMLV particles, we studied the generation of Moloney murine leukemia virus (MoMLV)/simian immunodeficiency virus (SIV) pseudotypes. Unlike HIV-1, both the wild-type SIV Env and a truncated form, which lacks most of the cytoplasmic domain of the transmembrane glycoprotein, were incorporated into MoMLV particles and generated infectious retroviral vectors which could transduce CD4+ sMAGI macaque cells. The infection depended on target cell CD4 expression, and was neutralized by both soluble CD4 and sera from SIV-infected macaques. We also observed pseudotype-mediated gene transfer of a green fluorescent protein marker into the CD4+ CEMX174 and C8166 lymphoid cell lines. More importantly, primary human lymphocytes were also successfully transduced ex vivo by MoMLV/SIV pseudotypes, albeit at lower efficiency, and gene transfer was specifically restricted to the CD4+ subset. These findings demonstrate that MoMLV/SIV pseudotypes can be used to transduce cells which are susceptible to SIV infection, and thus might be advantageously employed in animal models for direct in vivo delivery of gene therapy-based approaches.

DNA immunization of mice against SIVmac239 Gag and Env using Rev-independent expression plasmids

Simian immunodeficiency virus (SIV) structural gene expression, including gag and env, strictly depends on the interaction of the viral posttranscriptional regulator Rev with its target RNA, the Rev-responsive element (RRE). A small RNA element, termed the constitutive transport element (CTE), located in the 3' portion of simian retrovirus 1 (SRV-1) mRNA, can efficiently substitute for the human immunodeficiency virus (HIV) Rev-RRE interaction, and thus render HIV expression and replication Rev independent. We tested the ability of the SRV-1 CTE to drive the expression of SIVmac239 env and gag from subgenomic constructs designed for possible use in vaccine trials. In vitro expression studies showed that when the SRV-1 sequence is coupled to the SIV gag and env mRNAs, it functions in an orientation-dependent fashion, and leads to strong expression of SIV Gag and Env in human and monkey cell lines; levels of CTE-mediated protein expression were similar to those obtained with a functional Rev-RRE system. On the other hand, in murine fibroblast-like cells, SIV Gag and Env were expressed from constructs at relatively high levels even in the absence of Rev-RRE; nevertheless, their expression was increased by the presence of the SRV-1 CTE. As reported previously for HIV, the murine cell lines appeared to be defective for Rev-RRE activity, and required overexpression of Rev to induce a Rev response. Intramuscular injection of the gag-CTE and env-CTE constructs in BALB/c mice resulted in the expression of the corresponding mRNAs, and the production of anti-Gag and anti-Env antibodies, thus suggesting that these vectors might be used for genetic immunization approaches.

Rapid identification of viable retrovirus-transduced cells using the green fluorescent protein as a marker

Various methods for determining the expression of the beta-galactosidase (beta-gal) gene after retroviral transduction were compared as a means to assess retroviral titre. To allow better comparison, different retroviral vectors were constructed carrying two mutants of the green fluorescent protein and assessed as sensitive markers of retroviral gene transfer. It could be demonstrated that GFP is generally superior to beta-gal in terms of sensitivity, speed and non-invasiveness of assay, allowing easy direct FACS sorting of populations of transduced cells. This opens the possibility of enrichment by sorting of ex vivo transduced cells in gene therapy protocols.

Live attenuated simian immunodeficiency virus prevents super-infection by cloned SIVmac251 in cynomolgus monkeys

The ability of a live attenuated simian immunodeficiency virus (SIV) to protect against challenge with cloned SIVmac251/BK28 was evaluated in four cynomolgus macaques. The intravenous infection of the C8 variant of the SIVmac251/32H virus, carrying an in-frame 12 bp deletion in the nef gene, did not affect the CD4+ and CD8+ cell counts, and a persistent infection associated with an extremely low virus burden in peripheral blood mononuclear cells (PBMCs) was established. After 40 weeks, these monkeys were challenged intravenously with a 50 MID50 dose of SIVmac251/BK28 virus grown on macaque cells. Four naive monkeys were infected as controls. Monkeys were monitored for 62 weeks following challenge. Attempts to rescue virus from either PBMCs or bone marrow from the C8-vaccinated monkeys were unsuccessful, but in two cases virus was re-isolated from lymph node cells. The presence of the SIV provirus with the C8 variant genotype maintaining its original nef deletion was shown by differential PCR in PBMCs, lymph nodes and bone marrow. Furthermore, in contrast to the control monkeys, the vaccinated monkeys showed normal levels for CD4+ and CD8+ cells, minimal lymphoid hyperplasia and no clinical signs of infection. Our results confirm that vaccination with live attenuated virus can confer protection. This appears to be dependent on the ability of the C8 variant to establish a persistent but attenuated infection which is necessary for inducing an immune response, as suggested by the persistence of a strong immune B cell memory and by the over-expression of interleukin (IL)-2, interferon-gamma and IL-15 mRNAs in PBMCs of C8-vaccinated monkeys but not in those of control monkeys.

TCR expression and clonality analysis in peripheral blood and lymph nodes of HIV-infected patients

We compared the T cell receptor (TCR) V beta gene family repertoire in peripheral blood mononuclear cells (PBMC) and lymph node (LN) cells from 7 human immunodeficiency virus (HIV)-infected patients and 3 seronegative healthy controls. Virtually all the V beta family specificities were represented in patient PBMC and LN cells, and mean values for each specificity were comparable to figures in seronegative controls. In 4 patients, however, some V beta gene segment transcripts were overrepresented in the LN compartment, compared to the peripheral blood counterpart. To ascertain whether this phenomenon was due to polyclonal or oligoclonal expansion of T cells bearing the relevant V beta gene product, we sequenced the entire CDR3 region of a panel of 238 PCR clones corresponding to the V beta transcripts expanded in LN; as control, the same regions were cloned and sequenced in patient's PBMC, and in PBMC and LN cells from seronegative individuals. This analysis disclosed preferential usage of J beta 2 genes in PBMC and LN cells from both seropositive patients and controls, regardless of the V beta gene segment considered, thus indicating that this skewness in the V beta-J beta repertoire could be a consistent feature of at least a part of the V beta repertoire in different lymphoid compartments, regardless of the pathologic conditions. In addition, in LN from HIV seropositive patients we found the presence of recurrent TCR rearrangements, accounting for 8-23% of the generated clones, in each of the 4 V beta specificities analyzed; recurrent sequences were not found in PBMC from patients nor in PBMC and LN cells from seronegative controls. These findings suggest that antigen-driven oligoclonal T cell expansions may occur in vivo in lymphoid organs of HIV seropositive patients.

Cell proliferation as a predictor of response to chemotherapy in metastatic breast cancer: a prospective study

Many biologic prognostic markers are available for patients with breast cancer, and considerable interest has been devoted to confirm preliminary evidence of their role as indicators of treatment response. It remains to be assessed whether such markers are predictors of response only to first-line or also to successive therapies. Proliferative activity, defined by the 3H-thymidine labeling index (TLI), was determined on the primary lesion from 76 patients at time of first diagnosis. At relapse, patients underwent chemotherapy as absolute (48 cases) or relative (28 cases) first-line treatment, and their clinical response was analyzed in relation to the TLI of the primary lesion. The objective clinical response was significantly higher for rapidly (47%; CL, 33-61%) than for slowly proliferating tumors (15%; CL, 1-29%). These findings held true also when adjusted for metastatic site, previous treatment, chemotherapy regimen administered, and hormone receptor status. However, the direct relation between cell proliferation and benefit from chemotherapy held true only when such a treatment was used as an absolute first-line approach. Cell proliferation of primary lesions represents a consistent indicator of response to chemotherapy over time. Previously administered regimens, at least hormone therapy, could alter the proliferation-related chemosensitivity profile of individual tumors.

Effect of rIL-2 treatment on anti-tetanus toxoid response in the elderly

To explore the effects of interleukin-2 (IL-2) treatment in a vaccination protocol in the elderly, we administered low-dose rIL-2 to a group of aged subjects before primary tetanus toxoid immunization. A specific antibody response was detectable in the serum of 6/8 treated individuals after primary immunization, but in only 2/6 untreated controls; following antigenic boosting, specific antibody levels remained relatively unchanged in all the seroconverters. The data were confirmed by studying the ability to produce tetanus-specific antibodies in vitro, and by isoelectrofocusing analysis of serum anti-tetanus antibodies; this latter study showed a more restricted clonal response to the immunogen in untreated individuals. On the other hand, the study of the in vitro proliferative response to tetanus toxoid did not evidence clear differences between the two groups. On the whole, these data seem to indicate that a short-term rIL-2 treatment is able to potentiate the antibody response to tetanus toxoid, and may be a useful tool to improve humoral responses to vaccines in aged subjects.

Ovarian cancer: natural history and metastatic pattern

Ovarian cancer begins at a molecular level, however to date, our knowledge of genetic changes and mechanisms of ovarian tumorigenesis is limited. The natural history of ovarian cancer may depend on different anatomo-clinical and biological factors. In the life history of ovarian cancers the stage, histology, tumor grade, age of the patient and gene abnormalities, both oncogenes (c-myc, H-ra, new) and oncosuppressor genes (p53, in particular), DNA ploidy and steroid receptor status have important prognostic significance. Residual disease, when less than 1 cm, is another important prognostic factor, being significantly associated to the survival and, progression free, improvement in the survival. In the low stage ovarian cancer (Stage IA, IB, IAII,IBII,IC,IIA,IIB,IIC), adjuvant treatment seems not to influence Disease Free Survival (DFS) or Overall Survival (OS) The exception to this rule is when cisplatin regimen is assessed, as it can highly reduce the relapse rate while the survival is not significantly influenced. Ovarian cancers disseminate, primarily by continuity. Lymphatic dissemination to the pelvic and para-aortic lymph nodes (40% of patients at stage III-IV disease) as well as to the peritoneum is common. At the time of diagnosis, bone or brain metastases are rarely present and their presence is not related to the histology or grading of the tumor.

Analysis of Epstein-Barr virus (EBV) type and variant in spontaneous lymphoblastoid cells and Hu-SCID mouse tumours

Epstein-Barr virus (EBV) type and strain variations were examined using both lymphoblastoid cell lines (LCLs), spontaneously derived in vitro from peripheral blood mononuclear cells (PBMC) of 15 HIV-1-seropositive individuals; and SCID mouse tumours induced by inoculation of PBMC from 11 healthy human donors (Hu-SCID tumours). Polymerase chain reaction (PCR) analysis disclosed that all but one of the 26 EBV + samples harboured EBV nuclear antigen (EBNA) 2 and 3C type A virus. On the other hand, single strand conformation polymorphism (SSCP) analysis using Epstein-Barr encoded RNA (EBER) specific primers detected an AG876-like (type B) band pattern in 21 of the 26 EBV + samples. Three Hu-SCID tumours scored as B95.8-like (type A), and two showed neither a type A nor a type B SSCP migration pattern. Sequence analysis of the amplified EBER fragments confirmed the PCR-SSCP findings; moreover, additional mutations were present not only in the two EBV + samples with anomalous SSCP pattern, but also in two other samples with a standard SSCP profile. Thus, EBER analysis did not correlate with EBNA typing, and appeared to be unsuitable for EBV type assessment. Latent membrane protein (LMP) analysis disclosed, on the whole, sever size variants: as expected, the differences were due to the variable numbers of a 33-bp repeat in the amplified fragment, as assessed by direct sequencing. The broader variability detected by LMP analysis should prove more useful than typing for assessing the presence of single and/or mixed variants resulting from EBV reactivation and/or reinfection.

Potential role of growth factors in ovarian cancer

As with many other tumors, the origin and development of ovarian cancer is constituted by several molecular mechanisms, many of which are still unknown. Furthermore, data in the literature are incomplete and often contradictory, and they are mainly founded on results obtained on cell lines and not on observations based on the in vivo study of ovarian cancer. Despite this situation, the study of control mechanisms of proliferation and differentiation in normal ovarian functioning has enabled clinicians to identify certain growth factors and oncogenes which seem to have an important role in the neoplastic transformation of ovarian tissue. In this review, our aim is to summarise the most important data regarding function of growth factors and oncogene in normal and neoplastic epithelial ovarian cells.

The hu-PBL-SCID mouse in human lymphocyte function and lymphomagenesis studies: achievements and caveats

The chance isolation of a mouse strain mutant that shows a complete deficiency in both the humoral and cellular immunity compartments has opened new perspectives in numerous fields of medicine and biology, including oncology, hematology and immunology. However, the original concept that the severe combined immunodeficiency mouse might behave as a 'living vessel', and allow experimental approaches that are precluded in man by technical and ethical constraints, has not fully withstood the test of time. At present, despite the body of important results achieved in the past few years, the use of this model in some areas is somewhat deregulated; no standard protocols are available, and some critical variables that could affect experimental results are not always under control. In this article, we have focused on the use of the SCID mouse reconstituted with human mature lymphoid cells in immunological studies, and tried to enucleate, in the array of existing experimental work, some basic concepts that might favor more judicious and appropriate approaches to the use of this important experimental model.