Stress distribution in a tooth treated through minimally invasive access compared to one treated through traditional access: A finite element analysis study

Introduction

The purpose of this study was to compare the stress distributions in the teeth treated through minimally invasive access (MIA) designs to those of the teeth treated through traditional straight-line access and their relationship to the final restoration using three-dimensional finite element analysis (FEA).

Materials and Methods

Four FEA models of an extracted mandibular first molar were constructed. An intact model served as the control, whereas the other three were prepared with either an MIA or traditional straight-line access. Simulated composite access fillings with or without a simulated gold crown were applied to the models, followed by application of an occlusal load of 100 N. Von Mises stresses in the teeth were then calculated and analyzed.

Results

Stress values within the dentin for baseline, MIA with composite filling, MIA with composite filling and crown, and traditional access with composite filling and crown were 10.14 MPa, 6.98 MPa, 11.79 MPa, and 16.81 MPa, respectively. Higher stress values indicate that the tooth is more prone to fracture.

Conclusions

A traditional endodontic access cavity may render a tooth more susceptible to fracture compared with an MIA design.

First Report of Tomato chlorosis virus Infecting Sweet Pepper in Costa Rica

In September 2008, a survey of whiteflies and whitefly-borne viruses was performed in 11 pepper-growing greenhouses in the province of Cartago, Costa Rica. During this survey, the vast majority of sweet pepper (Capsicum annuum cv. Nataly) plants showed interveinal chlorosis, enations, necrosis, and mild upward leaf curling. Large populations of whiteflies were present and they were found to be composed only of Trialeurodes vaporariorum. Total RNA from frozen plant samples was extracted with TRI Reagent (Molecular Research Inc., Cincinnati, OH). RevertAid H Minus Reverse Transcriptase Kit (Fermentas, Hanover, MD) was used for reverse transcription of the total RNA extract, with cDNA synthesis directed using random primers. A real-time PCR assay was performed to detect Tomato chlorosis virus (ToCV) (genus Crinivirus, family Closteroviridae) using the SYBR Green PCR Master Mix (Applied Biosystems, Carlsbad, CA). Three sets of primers were used to confirm the presence of ToCV in the samples: TocQ875F/TocQ998R primer set directed to a fragment of 123 bp of the HSP gene (3); ToCVp22RQF (5'-TGGATCTCACTGGTTGCTTG-3')-ToCVp22RQR (5'-TAGTGTTTCAGCGCCAACAG-3') primer pair that amplifies a 198-bp segment of the ToCV p22 gene (R. Hammond, E. Hernandez, J. Guevara, J. A. Vargas, A. Solorzano, R. Castro, N. Barboza, F. Mora, and P. Ramirez, unpublished) and the ToCVCPmRQF (5'-CATTGGTTGGGGATTACGTC-3')-ToCVCPmRQR (5'-TCTCAGCCTTGACTTGAGCA-3') primer pair designed to amplify a 170-bp portion of the ToCV CPm gene (R. Hammond, E. Hernandez, J. Guevara, J. A. Vargas, A. Solorzano, R. Castro, N. Barboza, F. Mora and P. Ramirez, unpublished). Fifteen symptomatic samples per greenhouse were tested for a total of 165 sweet pepper plants. From this total, seven samples from four different greenhouses produced amplification of PCR products with all three sets of primers. One of the seven samples showed mild chlorosis, but others were highly chlorotic with different levels of upward leaf curling. None of the other samples showed amplification with any of the primer sets; the symptoms on these plants could have been due to nutritional deficiencies or infection by viruses. Sequence analysis of the 460-bp HSP PCR products, produced using previously reported primers (3), and 150-bp fragment of the P22 revealed 100% sequence identity with a tomato isolate of ToCV from the United States (GenBank Accession No. AY903448). Because of the low number of samples infected with ToCV and the high incidence of symptoms, DNA extraction and a begomovirus PCR detection assay was performed using primer pair AV494/AC1048 (4). Negative results were obtained for all samples. To our knowledge, this is the first report of ToCV infecting sweet pepper plants in Costa Rica and the third one worldwide. ToCV has also been found to be infecting tomato in open field and greenhouses (1) and other weeds in greenhouses including Ruta chalepensis (Rutaceae), Phytolacca icosandra (Phytolaccaceae), Plantago major (Plantaginaceae), and Brassica sp. (Brassicaceae) (2) in the same region of Costa Rica, suggesting that it has adapted to the conditions of the area and poses an important threat to the vegetable production. References: (1) R. M. Castro et al. Plant Dis. 93:970, 2009. (2) A. Solorzano-Morales et al. Plant Dis. 95:497, 2011. (3) W. M. Wintermantel et al. Phytopathology 98:1340, 2008. (4) S. Wyatt and J. Brown. Phytopathology 86:1288, 1996.

[Prevalence and clinical characteristics of the IBS subtypes according to the Rome III criteria in patients from a clinical, multicentric trial. A report from the Mexican IBS Working Group]

BACKGROUND

In Mexico the prevalence of irritable bowel síndrome (IBS) using Rome II criteria varies between 16 and 35%.

OBJECTIVE

To analyze the relative frequency of the IBS subtypes according to the Rome III criteria.

METHODS

A multicentric study in 1677 IBS-Rome III patients that consulted private medical clinics. They all answered a structured interview by their physicians to determine the IBS subtype and to evaluate their symptoms intensity (Likert Scales). Patients self-evaluated their symptoms as well by using 10 cm visual analog scales for each one.

RESULTS

Women represented 76.8% of the patients for a F:M ratio of 3.3:1. The relative frequencies of the IBS subtypes were IBS-M: 48.4%, IBS-E: 43.0%, IBS-D: 5.6% and IBS-U: 2.8% with females predominating among all. However, IBS-D included 1.7 to 2.4 times more men than any of the other subtypes. The IBS-M reported a higher frequency and intensity of halitosis and vomiting and a higher intensity of burping; while those with IBS-E reported a higher frequency and intensity of straining and the IBS-D more urgency for a bowel movement, fecal incontinence and mucous in the stools.

CONCLUSIONS

In IBS-Rome III patients in Mexico, IBS-M is the most common subtype and is more commonly associated with dyspeptic symptoms while the IBS-E reported more outlet symptoms and the IBS-D fecal incontinence. There is a higher female predominance amongst all, however men are more likely to be in IBS-D.

Interleukin-10 promoter polymorphisms in patients with systemic lupus erythematosus from the Canary Islands

The purpose of this study was to examine whether several allelic variants in the polymorphic interleukin (IL)-10 promoter region were related with an increased risk of developing systemic lupus erythematosus (SLE) in Spanish patients from Canary Islands. Microsatellites (MS) at positions -4000 and -1200 (IL10R and IL10G, respectively) and single nucleotide polymorphisms (SNPs) (MS) at positions -1082G/A, -819C/T and -592C/A of the IL-10 promoter were analysed in patients with SLE and healthy controls from Canary Islands (Spain). We found that SNPs but not MS were associated with SLE. The GCC haplotype frequency was significantly higher in SLE patients (0.43) than in healthy donors (0.33) [P = 0.02; OR = 1.50 (95% CI = 1.06-2.14)], whereas the ACC haplotype was less represented in patients (0.28 vs. 0.37) [P = 0.02; OR = 0.64 (95% CI = 0.44-0.92)]. To assess the functional role of genotypes, serum IL-10 levels from patients and controls were quantified by ELISA. Also, the lipopolysaccharide-induced IL-10 secretion by monocytes from healthy controls was evaluated in vitro. Serum IL-10 levels were higher in patients [median (interquartile range) = 2.8 pg/mL (1.8-4.2)] than in controls [0.9 pg/mL (0-3.5)] (P = 0.02), but no association was observed between serum IL-10 levels or lipopolysaccharide-induced IL-10 secretion and the IL-10 promoter haplotypes. These data suggest that the IL-10 promoter haplotype that produces higher levels of cytokine is associated with SLE in patients from Canary Islands.

Prognostic irrelevance of HLA-G in B-cell chronic lymphocytic leukemia

In the last few years, it has been suggested that the involvement of human leukocyte antigen-G (HLA-G) in several tumoral processes and its likely participation as a factor of immune tolerance in malignant cells. Recently, positive HLA-G surface expression has been associated with a poor prognosis in a small group of patients with B-cell chronic lymphocytic leukemia (B-CLL), a lymphoproliferative disorder characterized by a heterogeneous clinical course. In the present work, 169 patients suffering from B-CLL were analyzed for the expression of HLA-G by flow cytometry in order to verify its prognostic value in a larger cohort. We observed a low expression of this molecule on leukemic B cells and no significant relation to clinical data or progression-free survival time, indicating that this molecule is not as good immunologic prognostic marker for B-CLL as suggested.

HSP-70 as a nonspecific early marker in cisplatin ototoxicity

CONCLUSION

The great variety of pathological entities related to the presence of circulating HSP-70 suggests a nonspecific cellular damage. As the present study shows, positive results decrease with respect to the time elapsed after the injection of the ototoxic agent. HSP-70 appears as an early and transient marker that could permit early detection of inner ear damage.

OBJECTIVES

The aim of this study was to determine the presence of HSP-70 at different time points by means of Western blot immunoassay in the sera of rats treated with cisplatin.

MATERIALS AND METHODS

Thirty-six Wistar rats were intraperitoneally injected with cisplatin at a dose of 5 mg/kg and blood samples were collected at 7 and 90 days. Determination of HSP-70 was made by means of a modified Western blot immunoassay kit originally used for human HSP-70 antigen detection. A control group of 18 animals was used for comparison.

RESULTS

Western blot was positive in 77.8% of the animals in the 7 days group, decreasing to a 44.4% in the 90 days group. In the control group, Western blot was positive in 5.5%.

A sustained activation of PI3K/NF-kappaB pathway is critical for the survival of chronic lymphocytic leukemia B cells

The progressive rise of mature CD5+ B lymphocytes, despite the low proportion of proliferating cells, has led to the notion that B cell chronic lymphocytic leukemia (B-CLL) is primarily related to defective apoptosis. The microenvironment likely plays a prominent role because the malignant cells progressively accumulate in vivo, whereas they rapidly undergo spontaneous apoptosis when cultured in vitro. To assess microenvironment-mediated survival signals, B-CLL cells were cultured with a murine fibroblast cell line, Ltk-, with and without an agonistic antibody to CD40. Spontaneous apoptosis was associated with the loss of Akt and NF-kappaB activities. Interactions with fibroblasts sustained a basal level of Akt and NF-kappaB activities, which was dependent on phosphatidylinositol-3 kinase (PI3K). Constitutive activity of the PI3K pathway in B-CLL cells when cultured with fibroblasts prevented the downregulation of the prosurvival Bcl-2 family protein Bcl-xL and the caspase inhibitor proteins FLIPL and XIAP, and consequently caspase-3 activation and apoptosis. CD40 crosslinking in B-CLL cells did not further prevent murine fibroblasts-mediated apoptosis but induced cell proliferation, which was associated with an increase of Akt and NF-kappaB activation compared with cells cultured with fibroblasts alone. The PI3K pathway seems to play a pivotal role in B-CLL cell survival and growth.

Fenticonazole nitrate for treatment of vulvovaginitis: efficacy, safety, and tolerability of 1-gram ovules, administered as ultra-short 2-day regimen

Because of its potential as a low cost first-line monotherapy for the most common vulvovaginal infections, we evaluated fenticonazole nitrate in a prospective, open-label, multicenter pilot study with 101 sexually active women (per-protocol; 16 to 61 years of age) with vulvovaginitis involving single or mixed infections with Candida albicans, Trichomonas vaginalis, and/or Gardnerella vaginalis. Fenticonazole nitrate (1 g) was administered as vaginal ovules, once daily on days 1 and 3. Eradication (direct phase-contrast microscopy of vaginal swabs and/or microbiological culture) on day 8 was 90% (C. albicans, 26/29, p < 0.001), 70% (T. vaginalis, 7/10, p = 0.161), 67% (G. vaginalis, 22/33, p < 0.009), and 45% (mixed infection, 13/29, p = 0.001). After 28 days, relapse was 0% for candidiasis and trichomoniasis, 27% (6/22) for G. vaginalis, and 23% (3/13) for mixed infection. Overall, eradication of all offending pathogens was achieved in 67% of the total per-protocol population, with a relapse rate of only 16%. Score sums for symptoms improved from 7.0 (baseline) to 1.7 (day 8), and 0.71 (day 28), (p < 0.001). Treatment was safe and well tolerated. The results of our pilot study suggest that application of fenticonazole nitrate 1 g intravaginal ovules on 2 alternate days is a suitable first-line treatment of vulvovaginitis with acceptable broad-spectrum efficacy against the most commonly involved pathogens and with a low rate of early relapse, reserving antibiotics for patients with treatment failure or relapse of infection. Our results should encourage further examination of this approach in larger and well controlled clinical trials.

Host gender in parasitic infections of mammals: an evaluation of the female host supremacy paradigm

A review of current literature on mammalian hosts' sexual dimorphism (SD) in parasitic infections revealed that (1) it is a scarcely and superficially studied biological phenomenon of considerable significance for individual health, behavior, and lifestyles and for the evolution of species; (2) there are many notable exceptions to the rule of a favorable female bias in susceptibility to infection; (3) a complex network of molecular and cellular reactions connecting the host's immuno-neuroendocrine systems with those of the parasite is responsible for the host-parasite relationship rather than just an adaptive immune response and sex hormones; (4) a lack of gender-specific immune profiles in response to different infections; (5) the direct effects of the host hormones on parasite physiology may significantly contribute to SD in parasitism; and (6) the need to enrich the reductionist approach to complex biological issues, like SD, with more penetrating approaches to the study of cause-effect relationships, i.e., network theory. The review concludes by advising against generalization regarding SD and parasitism and by pointing to some of the most promising lines of research.

The dinucleotide repeat polymorphism in the 3'UTR of the CD154 gene has a functional role on protein expression and is associated with systemic lupus erythematosus

OBJECTIVE

To investigate the association of the (CA)n dinucleotide repeat in the 3' untranslated region (3'UTR) of the CD154 gene with systemic lupus erythematosus (SLE), and its functional role in protein expression.

METHODS

The allelic and genotypic distributions of the polymorphism were compared in 80 patients with SLE and 80 controls. A complete clinical and analytical database was recorded in each patient in order to correlate the clinical manifestations in SLE with different alleles. To investigate the functional role of the polymorphism, the CD154 protein expression on activated lymphocytes from healthy homozygous controls was evaluated by flow cytometry.

RESULTS

The 24 CA allele was the most represented in controls (p = 0.029), whereas the alleles containing >24 CA repeats were found in patients (p = 0.0043). Furthermore, when only homozygous women were considered, most controls carried two 24 CA alleles (p = 0.041), whereas most patients carried two alleles containing >24 CA repeats (p = 0.032). Also, patients carrying at least one 24 CA allele had less neurological involvement (p = 0.034), and carriers of at least one allele with fewer than 24 CA repeats presented more livedo reticularis (p = 0.006) and anti-Sm (p = 0.01) and anti-RNP (p = 0.038) autoantibodies. CD154 maximum expression in activated lymphocytes from all controls was reached after 54 hours, but it was more prolonged in controls carrying two alleles with >24 CA repeats (p = 0.0068).

CONCLUSION

The CD154 3'UTR microsatellite is associated with SLE, and the most represented alleles in patients were accompanied by a more prolonged protein expression in activated lymphocytes from controls.

Production of intracellular IL-2, TNF-alpha, and IFN-gamma by T cells in B-CLL

BACKGROUND

Recent evidence indicates that the slowly expanding population of CD5(+) B cells that characterizes B-cell chronic lymphocytic leukemia (B-CLL) could be related to defects in the response to cytokine produced by T cells that regulate apoptosis. We studied the intracellular expressions of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) in T-helper 1 cells (Th1 response) of B-CLL.

METHODS

Peripheral blood mononuclear cells from 21 healthy individuals and purified T cells from 21 early-stage and 15 late-stage B-CLL patients were activated with phorbol myristate acetate and ionomycin. The Th1 cytoplasmic cytokines were evaluated in CD4(+) and CD8(+) T cells by flow cytometry.

RESULTS

The percentages of CD4(+) and CD8(+) T cells positive for IL-2 were significantly lower in B-CLL patients than in healthy individuals (P = 0.030 and 0.049, respectively). No significant differences in TNF-alpha or IFN-gamma intracellular expressions were found between patients and healthy individuals. TNF-alpha- and IFN-gamma-expressing CD8 T cells were disease stage dependent, being significantly higher in late-stage patients (P < 0.001 for both cytokines).

CONCLUSIONS

Our present observations suggested that Th1 cytokines may be of major importance in the pathogenesis of B-CLL.

Nuclear androdioecy and gynodioecy

We formulate two single-locus Mendelian models, one for androdioecy and the other one for gynodioecy, each with 3 parameters: t the male (female) fertility rate of males (females) to hermaphrodites, s the fraction of the progeny derived from selfing; and g the fitness of inbreeders. Each model is expressed as a transformation of a 3 dimensional zygotic algebra, which we interpret as a rational map of the projective plane. We then study the dynamics for the evolution of each reproductive system; and compare our results with similar published models. In this process, we introduce a general concept of fitness and list some of its properties, obtaining a relative measure of population growth, computable as an eigenvalue of a mixed mating transformation for a population in equilibrium. Our results concur with previous models of the evolution of androdioecy and gynodioecy regarding the threshold values above which the sexual polymophism is stable, although the previous models assume constant the fraction of ovules from hermaphrodites that are self pollinated, while we assume constant the fraction of the progeny derived from selfing. A stable androdioecy requires more stringent conditions than a stable gynodioecy if the amount of pollen used for selfing is negligible in comparison with the total amount of pollen produced by hermaphrodites. Otherwise, both models are identical. We show explicitly that the genotype fitnesses depend linearly on their frequencies. Simulations show that any population not at equilibrium always converges to the equilibrium point of higher fitness. However, at intermediate steps, the fitness function occasionally decreases.

Flow-cytometric assessment of lymphocyte cytokine production in tuberculosis

We assessed by flow-cytometry the Th1/Th2 profiles in peripheral blood lymphocytes (PBL) from patients with active tuberculosis (TB), before and after antituberculous therapy, and from healthy tuberculin-positive and -negative reactors. PBL from patients showed a reduced potential for Th1-cytokine (notably IFN- gamma) production after culture with a policlonal stimulus. When these PBL from patients were cultured with a M. tuberculosis (MTB)-specific antigen such as PPD (10 microg/ml), there was no detectable production of Th1 cytokines. Only the Th2 cytokine IL10 was detected in PBL from patients but not from controls. However, at the site of the tuberculosis disease, T lymphocytes from bronchoalveolar lavage, after culture with PPD, produced IFN- gamma. After completion of tuberculosis therapy, PBL did not produce IL10. These data indicate that the immunosuppression observed in PBL during active tuberculosis infection may be related to IL10 production, and to the compartmentalization of the antigen-Th1 response to sites of active MTB infection.

[Study of pulmonary lesions with (99m)Tc-Tetrafosmin and chest spect. Determination of uptake related factors, diagnostic value and prognosis]

One hundred fifteen patients with 119 pulmonary lesions in which malignancy was suspected underwent a SPECT study with 99mTc-Tetrofosmin (TTF) to assess the possible factors involved in the uptake of the radiopharmaceutical. The TTF uptake rate in the lung tumor with respect to that of healthy tissue (TTF index) was evaluated in terms of: benignity and malignancy, histological type, stage, cell differentiation, size, necrosis, survival and the influence of P-glycoprotein (Pgp), detected by immunohistochemistry, on the TTF uptake. The mean TTF index in the 18 benign lesions studied was 1.01 0.05, while that of the 101 malignant lesions was 1.59 0.45 (p < 0.001), with a positive predictive value of 97.7% and a negative predictive value of 50%. The comparison of the histological types, degree of cell differentiation, necrosis and stage revealed no statistically significant differences. With respect to size, those tumors measuring > 3 cm showed greater uptake than smaller lesions. In patients with non-small cell lung cancer, a positive relationship was observed between the TTF index and survival, a circumstance that did not occur in patients with small cell lung cancer. In the cases in which the presence of Pgp was assessed, there was an inverse relationship between the TTF ratio and Pgp expression. In conclusion, thoracic SPECT with 99mTc-TTF has a high positive predictive value for the presence of lung cancer, although a negative study does not rule out the existence of the disease. The reason for this is the inverse relationship between 99mTc-TTF uptake and the density of Pgp expression.

Does the serological testing really play a role in the diagnosis immune-mediated inner ear disease?

In order to analyse the clinical presentation and laboratory tests used for the diagnosis of immune-mediated sensorineural hearing loss (IMSNHL) a prospective study was conducted involving 125 patients affected by diverse clinical forms of the disease. The following methods were used: analysis of clinical evolution, pure-tone audiometry, determination of the immunophenotype of peripheral blood lymphocytes, immunoglobulins, complement factors C3 and C4, erythrocyte sedimentation rate, antinuclear autoantibodies (ANA) and heat shock protein 70 and the response to therapy. Levels CD4 (p = 0.03) and CD4CD45RA (p = 0.002) T cells were significantly reduced in patients with sudden sensorineural hearing loss. ANA were found in 34.4% of patients and the incidence of antibodies to HSP-70 was similar in both patients and control subjects. Diagnosis of IMSNHL is still based on clinical impressions as laboratory testing is not sufficiently diagnostic. However, the long-term evolution of IMSNHL presented by the patients included in this study may explain the negative results obtained in the tests. The existence of a typical profile patient, including the clinical course, immunological changes (presence of ANA and detection of abnormalities in T-cell subpopulations) and the response to steroid therapy can facilitate diagnosis. Further investigation to help identify a specific marker characteristic of IMSNHL is required.

Genetic associations under mixed mating systems: the Bennett-Binet effect

Using elementary algebraic geometry and computational commutative algebra, supported by the program Macaulay2, we studied and developed operators that define the zygotic and gametic evolution under a mixed-mating system with parameters s selfing rate, r recombination rate, and g relative fitness of inbreeders, for any possible combination of initial zygotic or gametic frequencies with two alleles at each of two loci. We found that (i) the allelic frequencies are preserved in every generation; (ii) the gametic frequencies converge to values that depend exclusively on the allelic frequencies; (iii) every zygotic population converges to a population in equilibrium with double heterozygotes equally frequent; (iv) the rate of convergence decreases to arbitrary small values with sufficiently small values of r or with sufficiently large values of s and (v) as g decreases, the maximal 'association between the two loci' occurs with higher values of selfing. We also found generalizations for the case of several alleles at each locus.

Aminoguanidine reduces apoptosis of circulating V Beta 8.2 T lymphocytes in Lewis rats with actively induced experimental autoimmune encephalomyelitis. Association with persistent inflammation of the central nervous system and lack of recovery

Aminoguanidine therapy delayed the onset of actively induced EAE in Lewis rats, but recovery was impaired in most animals. In the central nervous system this was correlated with persistent inflammation and production of proinflammatory cytokines. In the periphery of aminoguanidine-treated animals, T lymphocytes showed increased proliferation against myelin basic protein, and the percentage of Vbeta 8.2(+) T lymphocytes undergoing early apoptosis was markedly decreased, although it was unchanged in Vbeta 8.2(+) T cells isolated from the spinal cord. These results suggest that the prolonged survival of circulating encephalitogenic cells achieved by aminoguanidine would favor a longer lasting entry of these cells into the nervous system resulting in persistent inflammation and lack of recovery.

Role of viral and Mycoplasma pneumoniae infection in idiopathic sudden sensorineural hearing loss

Sudden deafness constitutes a challenge in terms of the etiopathogenic diagnosis. The causative origin of sudden deafness usually remains unknown. However, available evidence suggests that viral and Mycoplasma pneumoniae infection could be one factor involved. In order to analyze the incidence of these infectious agents, a microbiology study was carried out during the acute phase of the disease, and during convalescence, in 24 patients (17 men and 7 women; mean age 39.7 years; range 17-63 years) with idiopathic sudden hearing loss (SHL) according to previously published criteria. In the acute phase most of the patients presented IgG antibodies to Epstein-Barr virus (n = 23), herpes simplex virus (n = 24), parainfluenza virus (n = 24), varicella-zoster virus (n = 24) and cytomegalovirus (n = 20). Results obtained from 3 patients suggested the existence of a recent infectious process caused by Mycoplasma pneumoniae (IgM+) in 1 patient, Mycoplasma (IgM+) and influenza A virus (complement fixation titer > 1/64) in another and parainfluenza virus seroconversion (a fourfold higher titer between the acute phase and convalescence) in the third. In conclusion, the low incidence of documented positive serological tests in our series (12.5%) may be due to the presence of pathological situations other than acute infection and does not justify routine serological studies in patients with SHL.

Candida infection of cerebrospinal fluid shunt devices: report of two cases and review of the literature

Use of CSF shunt devices is a common practice in neurosurgery, and infection of the shunt is the most frequent complication. In spite of the fact that bacteria are the most widely implicated pathogens, reports of fungal infections, especially due to Candida sp., have increased in recent years. Their reported frequency ranges between 6% and 17%. Many factors have been implicated in the pathogenesis of Candida meningitis, such as broad spectrum antibiotics used in the treatment of a bacterial meningitis, steroids and indwelling bladder and intravenous catheters. The treatment of Candida meningitis still consists of systemic antifungal agents and removal of the shunt.

Modulation of apoptosis by cytokines in B-cell chronic lymphocytic leukemia

B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the slow and progressive accumulation of monoclonal apparently mature, CD5(+) B lymphocytes. The majority of circulating cells appear to be nondividing, and it has been suggested that a prolonged life span is mainly responsible for the accumulation of the leukemic cells. However, spontaneous programmed cell death by apoptosis occurs when B chronic lymphocytic leukemia cells are cultured in vitro. This may be because of the lack of an unidentified essential cytokine present in vivo. Thus, we investigate interleukin-2 (IL-2), IL-4, IL-6 and IL-10 in vitro effects on apoptosis of B cells from 32 previously untreated patients with B-CLL in initial clinical stages. B cells were isolated from peripheral blood, and apoptosis was measured in these cells immediately after isolation and following incubation in vitro, without and with the different cytokines, for 24 and 48 h. Distribution of cellular DNA content and quantitative analysis of apoptosis were determined by standard propidium iodide staining and flow cytometry. Spontaneous apoptosis occurred in B-CLL cells incubated in vitro in the absence of cytokines. Our results indicate that both IL-2 and IL-4, but not IL-6, inhibit in vitro apoptosis in a large percentage of B-CLL patients. IL-10 increases in vitro apoptotic cell number in stage 0 patients, but not in stage I and II. These data support the hypothesis that IL-2 or IL-4, may be cell survival factors in vivo and that IL-10 might be a candidate for immune therapy of early B-CLL.

Characterization of adrenal medullary chromaffin cells by flow cytometry

BACKGROUND

Adrenomedullary chromaffin cells are neural crest derivatives widely used as a model system to study neurosecretory mechanisms. Morphological, immunohistochemical, and functional data indicate that chromaffin cells are heterogeneous and support the distinction between adrenaline (A)- and noradrenaline (NA)-producing and secreting cells. The aim of this study was to characterize by flow cytometry the two main chromaffin cell subtypes in suspensions of cultured bovine chromaffin cells.

METHODS

An indirect immunofluorescence method was used for the specific labeling of two intracellular enzymes, dopamine beta-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT), involved in the synthesis of NA and A, respectively. Flow cytometry analysis of fluorescence labeling was performed in two chromaffin cell fractions differentially enriched in A-containing cells by centrifugation through density gradients. PNMT and DBH-related fluorescence was also correlated with the A and NA content of the cells assayed by HPLC measurements.

RESULTS

No significant differences were found in forward-side scatter plots between the two cell fractions (A-enriched cells and mixed cells); however, the degree of labeling of the enzymes and the corresponding PNMT/DBH-related fluorescence ratio was significantly greater in the A-enriched cell fraction. The existence of changes in DBH and PNMT content of chromaffin cells over time (1 week) in culture was also examined. No significant variation in enzyme related fluorescence values was detected in any of the two cell fractions, and this result correlated well with HPLC determinations of the catecholamine content (A and NA) of the cells.

CONCLUSIONS

Flow cytometry appears to be a useful technique to characterize chromaffin cell subtypes and to follow their phenotypic changes in response to growth factors.

[Preliminary study by flow cytometry of the cell cycle and DNA quantification in cytokeratin-positive cells in tumors of the head and neck]

DNA ploidy and cell-cycle distribution were determined by flow cytometry in fresh tumor tissue of 27 epithelial head and neck carcinomas. Epithelial cells were labeled with a fluorescein-isothiocyanate-conjugated cytokeratin antibody to study the possible influence of contaminating stromal and inflammatory cells on the results of cell-cycle analysis of tumor cells. The patient sample included 26 men and 1 women with a mean age of 60 years. Without cytokeratin gating, 11/27 tumors (40.74%) were aneuploid. After selecting the cytokeratin population, 10 more aneuploid tumors were found that had not been detected when considering the total population. Therefore, aneuploid tumors increased from 40.74% to 77.74%. The remaining 6/27 (22.26%) tumors were diploid. In the tumors that were either aneuploid without cytokeratin gating or diploid, the S-phase and G2M phase were significantly higher after cytokeratin staining, specially in diploid tumors (24.2% versus 10% and 6.8% versus 3.2%, respectively, p < 0.01). Therefore, in head and neck tumors cytokeratin staining optimizes both the determination of DNA ploidy and cell-cycle analysis, which is advantageous for tumor staging and prognosis assessment in these patients.

Cogan's syndrome: an oculo-audiovestibular disease

Typical Cogan's syndrome is a rare disease of young adults consisting of flares of interstitial keratitis and sudden onset of Ménière-like attacks (nausea, vomiting, tinnitus, vertigo and hearing loss). Life-threatening aortic insufficiency develops in 10% of reported cases. Atypical Cogan's syndrome (audiovestibular dysfunction with other types of inflammatory eye disease) is associated with vasculitis in 20% of cases and has a less favourable prognosis than typical Cogan's syndrome.

[Inflammatory pseudotumor of the larynx]

Inflammatory pseudotumors are rare and usually located in lung, although they can develop in any organ. They are unusual in head and neck and very rare in the larynx. A case of laryngeal pseudotumor in a patient with odinophagia and neck pain is reported. After diagnosis, the patient was treated with steroids, which produced complete resolution. These lesions can simulate malignant neoplasms and must be considered in the differential diagnosis.

[Correlation between 99m Tc-tetrofosmin uptake and P-glycoprotein expression in non-small-cell lung cancer]

We used thoracic SPECT to study the 99mTc-tetrofosmin (TF) uptake in patients with non-small-cell-lung-carcinoma (NSCLC). The results were compared with the percentage of P-glycoprotein (Pgp) found in flow cytometric analysis (FC) of samples of surgically-resected tumor tissue.

MATERIAL AND METHODS

A total of 21 patients with NSCLC were studied by means 99mTC-TF and thoracic SPECT. Image analysis included the determination of the TF uptake rate in the lung mass with respect to that of healthy tissue of the contralateral lung. These rates were compared with the percentage of Pgp expression according to FC. FC analysis was also carried out in 16 samples of healthy lung tissue obtained from the patients.

RESULTS

In healthy lung tissue, the mean Pgp expression according to FC was 4.58 +/- 1.87%. The cutoff value used to differentiate between Pgp positive and Pgp negative tumors was considered to be the mean plus two standard deviations (8.32). The Pgp-positive tumors (> 8.32%) presented significantly lower uptake levels (1.28 +/- 0.39) than the Pgp-negative lesions (1.66 +/- 0.33) (p = 0.029).

CONCLUSIONS

There is a inverse correlation between the Pgp expression as determined by FC analysis and 99mTc-TF in NSCLC. Thus, this radiopharmaceutical provides rapid and non-invasive information on Pgp expression in these lesions.

[Sudden hearing loss and uveitis as a form of presentation of neurosarcoidosis]

Sarcoidosis is a multisystem granulomatous disease of unknown cause with frequent pulmonary, ocular, and lymphatic system manifestations. Central nervous system involvement, although rare (1 to 5%), most commonly affects the cranial nerves. Cranial nerve VIII abnormalities occur in 20% of these patients and are associated with other neuropathies and organ or system involvement. We report a case of neurosarcoidosis that presented as isolated sudden sensorineural hearing loss and uveitis.

Effect of dehydroepiandrosterone (DHEA) on intestinal mucosal immunity in young adult and aging rats

The present study assesses the effectiveness of oral DHEA on the intestinal mucosal immune response in aging rats. Young adult (6 months) and aging (21 months) female rats received powdered rat chow with or without 0.2% DHEA for 23 days. The animals were immunized intraduodenally with either cholera toxin (CTx) or vehicle alone and boosted two weeks later. Seven days after boosting, serum, bile, small intestinal tissue, and liver were collected for analysis. Anti-CTx IgA antibody titers were measured in serum and bile and the concentration of anti-CTx antibody containing cells (ACCs) in the small intestinal lamina propria and liver were determined by quantitative immunohistochemistry. Intergroup comparisons indicated that there was only one significant difference in serum and none in bile anti-CTx IgA titers between CTx-immunized animals fed DHEA or the diet alone. Immunohistochemical analysis determined that the density and distribution patterns of ACCs within the lamina propria were unaffected by DHEA. Both DHEA-treated and control young immunized animals exhibited similar numbers of ACCs. Only 40% of the aging rats responded to intraduodenal immunization with CTx, as determined by the presence of ACCs in the intestine, regardless of the presence or absence of DHEA in the diet. These data suggest that DHEA in the diet does not enhance the intestinal mucosal immune response to intraduodenal CTx in either young adult or aging rats.

Prognostic significance of natural killer cell activity in patients with laryngeal carcinoma

BACKGROUND

For laryngeal carcinoma, the present TNM clinical staging system does not seem completely satisfactory as a guide for providing a prognosis for survival. We believe that natural killer cell activity would probably have a role in a more reliable system. Therefore, we analyzed the disease outcome with previously untreated epidermoid carcinoma of the larynx, evaluating classic clinical and pathologic factors, as well as natural killer cell activity in peripheral blood samples of the patients.

OBJECTIVES

To determine the level of natural killer cell activity in patients with laryngeal carcinoma and to analyze the prognostic value of this finding when associated with other clinical and pathologic variables.

DESIGN

Prospective cohort study of surveillance of laryngeal cancer. Mean follow-up of 42.8 months.

SETTINGS

Tertiary care referral center and ambulatory and hospitalized care.

PARTICIPANTS

We compared 81 men (mean age, 62.4 years; range, 35-89 years) with laryngeal carcinoma with 44 healthy men serving as control subjects (mean age, 57.6 years; range, 37-82 years).

RESULTS

Natural killer cell activity was significantly reduced in patients who had died of cancer-related causes in comparison with tumor-free survivors. Overall actuarial survival differed significantly in histologically assessed nodal involvement and low natural killer cell activity. Use of the Cox proportional hazards regression model showed that the factors that seem to have a prognostic effect on survival are histologically determined nodal involvement and low natural killer cell activity.

CONCLUSIONS

These results support the prognostic significance of the determination of pretreatment natural killer cell activity in peripheral blood samples from patients with laryngeal carcinoma and suggest that assessment of adding such a determination to the current tumor staging system is advisable.

In vitro transplantation of fetal human retinal pigment epithelial cells onto human cadaver Bruch's membrane

Retinal pigment epithelium transplantation has been proposed as adjunctive treatment for age-related macular degeneration following surgical excision of choroidal neovascular membranes. The goal of this study was to develop a model to evaluate retinal pigment epithelium transplantation onto human Bruch's membrane in vitro. We investigated the ability of cultured fetal human retinal pigment epithelium to colonize human cadaver Bruch's membrane, determined the incubation time needed to form a monolayer and to exhibit apical microvilli and tight junctions, and assessed the production of basement membrane. Freshly enucleated (less than 48 hours old) human eyes were cut through the pars plana, and the anterior segment, vitreous, and retina were removed. The native retinal pigment epithelium was debrided with a surgical sponge. Bruch's membrane and choroid at the macula were trephined with a 7.0 mm diameter trephine and then incubated with 1/2 ml of Dulbecco's modified Eagle's medium +15% fetal calf serum+basic fibroblast growth factor (1 ng ml-1), and fetal human retinal pigment epithelium at a concentration of 242,000 cells ml-1. Specimens were incubated for 1, 4, 6, 8, 12, or 24 hours. The specimens were fixed in half strength Karnovsky's fixative, processed, and analysed with scanning and transmission electron microscopy. The retinal pigment epithelium covered the debrided macular specimens to different degrees at different incubation times. After 1 hour, the cells started to attach and flatten (median percent coverage: 78%). The extent of Bruch's membrane coverage by fetal retinal pigment epithelium varied greatly between specimens. After 4-6 hours, the cells covered the entire debrided surface in a monolayer (median percent coverage: 97.2% at 4 hours, 99.8% at 6 hours). Tight junctions were observed, and the cells had few apical microvilli. The lateral cell borders were obliquely oriented with respect to Bruch's membrane, and the nuclei were elongated, exhibited prominent nucleoli, and were oriented parallel to Bruch's membrane. After 6-8 hours, cells started to become hexagonal (median percent coverage at 8 hours: 99.97%). Cells attached to the inner collagenous layer tended to be flatter than cells attached to residual native basement membrane. At 12 and 24 hours, expression of hexagonal shape, tight junctions, and apical microvilli were observed more frequently (median percent coverage: 99.87% at 12 and 100% at 24 hours). No newly formed basement membrane was observed at these time points. In separate experiments comparing attachment in the presence and absence of native RPE basement membrane, the presence of native retinal pigment epithelial basement membrane promoted the early attachment of the cells and more rapid expression of normal morphology. This in vitro system provides a reproducible way to study the adherence of retinal pigment epithelium to normal and diseased human Bruch's membrane.

[Immune-mediated inner ear disease: report of clinical cases]

Many clinical and experimental studies have obtained evidence of immune-mediated inner ear disease. Discrepancies between theories of the mechanisms of injury to the inner ear and the laboratory tests that identify it mean that the diagnosis is based on clinical symptoms and a positive response to treatment. We report four cases of immune-mediated inner ear disease characterized by endolymphatic hydrops, fluctuating hearing loss, sudden deafness (first symptom of primary Sjögren's syndrome), and rapidly progressive sensorineural hearing loss.

Association of sarcoidosis, low-grade B-lymphoma and epidermoid carcinoma

We report on a case of the so-called sarcoidosis-lymphoma syndrome in a 65-years-old man diagnosed as having sarcoidosis and, four years later, neurosarcoidosis. The diagnoses of epidermoid carcinoma of the skin and of stage IV monocytoid, small cell lymphocytic lymphoma were made five and seven years, respectively, after the initial diagnosis of sarcoidosis. It has been suggested that the increased mitotic activity of lymphocytes observed in sarcoidosis, favours their malignant transformation. Hypothetically, sarcoidosis might also influence the development of epidermoid carcinomas by depletion of circulating T4 lymphocytes and decreased resistance to oncogenic viruses that could lead to decreased tumour rejection in the epithelia exposed to carcinogenic stimuli.

Induction of apoptosis by 2-chlorodeoxyadenosine in B cell chronic lymphocytic leukemia

We investigated whether 2-chlorodexoyadenosine could induce apoptosis in B cell chronic lymphocytic leukemia (B-CLL) cells in vitro using clinically achievable drug doses, measuring apoptosis ratio by flow cytometry. B cells were isolated from previously untreated patients and apoptosis was measured in these cells immediately after isolation and following incubation in vitro, without and with 2-chlorodeoxyadenosine at different concentrations, for 24 and 48 h. Distribution of cellular DNA content and quantitative analysis of apoptosis were determined by standard propidium iodide staining and flow cytometry. Spontaneous apoptosis occurred in B-CLL cells incubated in vitro in the absence of drug, but the level of apoptosis was greater in cells treated with 2-chlorodeoxyadenosine after the second day of culture. The present in vitro study of B-CLL cells from previously untreated patients suggests this chemotherapeutic agent activates a program of cell death by apoptosis using a drug dose equivalent to the physiological concentration used in patients in vivo. These data reveal an interesting possibility in the 2-chlorodeoxyadenosine treatment of untreated patients by neoplastic B cell apoptosis induction.

Deficiency of naive T cells in patients with sudden deafness

BACKGROUND

Although there are a number of reports concerned with the role of immunity in the sudden onset of progressive sensorineural hearing loss, there are few references dealing with the involvement of immune-mediated mechanisms in sudden deafness.

OBJECTIVES

To study the phenotype of peripheral blood lymphocytes in a group of patients with sudden deafness by use of 3-color flow cytometry.

DESIGN

The study was carried out prior to the start of steroid therapy. Fourteen patients underwent a follow-up study once steroid therapy had been completed. Prospective analysis, case-control.

SETTING

Tertiary case referral center, ambulatory and hospitalized care.

PATIENTS

Twenty-two patients (13 men and 9 women; mean age, 45.3 years) were compared with 14 healthy control subjects (9 men and 5 women; mean age, 36 years). Patients were divided in 2 groups according to their response to steroid therapy.

RESULTS

Decreased numbers of both CD4+ helper cells (38.4% vs 45.5%; P = .04) and CD8+ cytotoxic cells (17.5% vs 22.3%; P = .02) were observed in patients and compared with those in the control subjects, as well as reduced numbers of CD4+CD45RA+ cells (14.4% vs 29.3%; P = .01) and CD8+CD45RA+ naive cells (18.2% vs 25.4%; P = .04). In the group of patients with a good response to steroid therapy (group 1), a tendency toward normalization of the CD4+ (pretreatment, 38.6%; posttreatment, 44.6%), CD4+CD45RA+ (pretreatment, 15.2%; posttreatment, 21.7%), and CD4+CD45RO+ (pretreatment, 21.1%; posttreatment, 18.2%) cell counts was observed, with a slight decrease in the CD8+ population (pretreatment, 18%; posttreatment, 15.7%). However, in patients with a poorer response (group 2), while there were increases in the CD4+ (pretreatment, 38%, posttreatment, 50%) and CD4+CD45RA+ (pretreatment, 12.8%; posttreatment, 16.7%) cell counts after steroid therapy, there was a significant increment in the CD4+CD45RO+ memory cell count (pretreatment, 14.1%; posttreatment, 28.5%) and low CD8+CD45RA+ counts (pretreatment, 14.6%; posttreatment, 15.5%). No differences were observed in the numbers of B or natural killer cells or in the presence of activation antigens CD25 and HLA-DR when pretreatment and posttreatment levels were compared.

CONCLUSION

These results demonstrate significant abnormalities in the subpopulations of lymphocytes in patients with sudden hearing loss, suggesting the existence of immune-mediated responses in the inner ear as possible etiopathogenic factors in this entity.

Natural killer cell proliferation and renal disease: a functional and phenotypic study

We describe a 57-year-old woman who presented with a constitutional syndrome, glomerulonephritis, and lymphocytosis. The phenotypic study, using flow cytometry, showed an expansion of natural killer (NK) cells (CD2+, CD3-, CD16+, CD56+, and CD7+). We performed a functional study of peripheral blood mononuclear cells (PBMCs) and of purified CD16+ cells (NK cells) and CD3+ cells (normal T cells). The expanded NK cell population, CD16+, did not proliferate with phytohemagglutinin (PHA) or anti-CD3 but showed a dose-dependent proliferation with recombinant interleukin-2 (rIL-2) and also proliferated with phorbol dibutyrate. This population showed very strong NK and lymphokine-activated killer cell (LAK) activities. The patient's symptoms resolved spontaneously without treatment. Three years later, however, there is still abnormal renal function, and the expansion of NK cells persists, although with no indication of malignancy. We review the features of the different large granular lymphocyte proliferations and their seldom described relationship with renal disease.

[Study of spontaneous cytotoxic activity in laryngeal carcinoma: prognostic value]

The status of natural killer (NK) cell activity in peripheral blood, based on number and functional state, was studied in relation to the clinical and histopathologic stage of 52 patients with laryngeal carcinoma and in 23 healthy controls. The number of NK cells, estimated using CD16 and CD56 monoclonal antibodies, was similar in patients and controls and showed no relation to tumor size and nodal involvement. NK cell function did not show significant differences in spontaneous cytotoxic activity either overall or in relation to tumor size and the presence of palpable lymph nodes. However, cytotoxic activity was significantly lower in patients who had histologically confirmed nodal involvement. NK activity under 36% (the percentage of specific lysis at an effector:target dilution of 50:1) was suggested the probable presence of nodal metastases and was a highly sensitive and specific test. In patients with laryngeal carcinoma, NK-cell cytotoxic activity may be an independent prognostic parameter for evaluating cervical lymph node involvement.

Acquired pure red cell aplasia: a study of six cases

Persistent infection by parvovirus B19 associated with pure red cell aplasia (PRCA) has been documented in immunocompromised patients. Bone marrow failure is associated with conditions in which immune surveillance is impaired, and in these instances occult parvovirus infection may be suspected. In this study we have assessed by serological and molecular methods whether parvovirus B19 infection may be a more frequent cause of PRCA than hitherto suspected and whether it may be present in the absence of a typical bone marrow picture. Six patients with PRCA--two with isolated PRCA and no apparent underlying disease, two with a lymphoproliferative disease, one with thymoma, and one with chronic myelomonocytic leukemia--have been studied. Four of the six patients had overt PCRA and were clearly immunocompromised. Parvovirus B19 was not detected in any of the six patients by PCR analysis and serology investigating the presence of IgM or IgG antibodies. Although parvovirus B19 infection needs to be ruled out in PRCA it represents only one, and probably not the most frequent, etiological factor of PRCA.

Natural killer cell activity in patients with pernicious anemia

Patients with pernicious anemia have an estimated risk of gastric adenocarcinoma that ranges from three- to fivefold greater than that of the general population. It has been reported that NK cells may be involved in immunosurveillance against tumor spread. The natural killer cell activity of peripheral blood mononuclear cells was analyzed in 22 patients with pernicious anemia and in 19 healthy controls. Levels of natural killer cell activity against K-562 target cells were similar in control subjects and patients, regardless of gastrin levels and time elapsed since diagnosis. According to quantitative flow cytometry analysis, similar percentages of phenotypically defined NK cells (CD16+) were found in peripheral blood mononuclear cells from patients and healthy controls. Our results show that in pernicious anemia patients, the percentage of NK cells present in peripheral blood mononuclear cells and their lytic activity are normal.

Functional defect of T cells in autoimmune gastritis

The functional response and phenotypic characterisation of peripheral blood T cells were studied in 41 patients with autoimmune gastritis--nine patients with autoimmune gastritis alone, 11 with untreated pernicious anaemia, and 21 with resolved pernicious anaemia who were taking vitamin B-12. Phenotypic analysis showed no changes in the CD4/CD8 ratio in any group of patients. CD3+ cells were significantly decreased and CD16+ cells were significantly increased in patients with autoimmune gastritis alone. Phytohaemagglutinin induced T cell proliferation, with or without interleukin 2, was reduced in the three groups. T cell proliferation induced by phorbol myristate acetate was normal. Interleukin 2 production of phytohaemagglutinin-stimulated lymphocytes was normal in the three groups. Five patients with pernicious anaemia treated with vitamin B-12 were followed and persistent hypoproliferation of T cells in response to phytohaemagglutinin was observed. The follow up study of the phenotype of these patients showed a significant increase of the CD2+ CD3- lymphocyte population after six months' treatment. In conclusion, the three groups of autoimmune gastritis patients studied have a functional defect in T cells that is independent of B-12 treatment and of the presence of pernicious anaemia.

Impaired natural killer cytotoxicity in peripheral blood mononuclear cells in Graves' disease

We studied the natural killer (NK) activity of peripheral blood mononuclear cells (PBMC) in patients with Graves' disease (GD). Peripheral blood mononuclear cells from 20 untreated hyperthyroid patients with GD showed a significantly reduced NK activity against 51 Cr-labeled K562 cells (33.9 +/- 15.9%), while in 32 euthyroid patients under antithyroid drug therapy. NK activity was similar to that of controls (46.9 +/- 17.3 and 49.9 +/- 20.2%, respectively). Furthermore, normalization of thyroid function with antithyroid drugs was associated with a significant increase and normalization of NK activity during the follow-up of nine GD patients (from 29.2 +/- 17.9 to 48.1 +/- 16.5%). This phenomenon could not be ascribed to a defective number of NK cells because the amounts of CD56+ and CD16+ cells in PBMC from both hyperthyroid and euthyroid GD patients were within normal ranges. Natural killer activity of PBMC from patients with toxic multinodular goiter was similar to that of normal controls (45 +/- 12.8 to 49.9 +/- 20%). No correlation was found between natural killer activity and serum levels of free thyroxine, TSH-inhibitory immunoglobulins, thyroidal antibodies to thryoglobulin and thyroidal microsomal antigen, dose or duration of antithyroid drug therapy. Natural killer activity from both controls and GD patients was enhanced in vitro by addition of recombinant interleukin 2 (IL-2), reaching control levels in hyperthyroid patients. These abnormalities were not associated with a defective IL-2 production by T cells, nor with a decreased IL-2R expression. We conclude that in untreated Graves' disease there is a decrease in NK cell activity in PBMC, probably dependent on the autoimmune process.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of cellular chemoresistance in keratinocytes by activation of different oncogenes

Response to chemotherapeutic agents in malignant tumors depends on many factors, most of which are as yet unknown. We investigated the correlation between the activation of different oncogenes and protein-kinase-C (PKC) modulation, and the cytotoxicity of some of the most widely used anti-cancer drugs. We transformed the murine keratinocyte cell line PAM 212, with different oncogenes (v-H-ras, v-myc and adenovirus E1a) and a mutant p53 suppressor gene (mp53). The cytotoxic effect of cisplatin (CDDP), doxorubicin (DOX) and vincristine (VCR), together with the concomitant action of modulators of PKC, TPA and staurosporine were evaluated by the crystal-violet method, thymidine incorporation and flow cytometry. We report that (a) the oncogene v-H-ras induces resistance to CDDP (> 50%), DOX (> 25%) and VCR (> 20%); (b) the E1a oncogene induces only resistance to VCR (> 40%) and marked sensitivity to CDDP and DOX; (c) the mp53 oncogene induces more resistance to VCR and insignificant resistance to the other drugs; and (d) activation of PKC by TPA increases the resistance to VCR and DOX in cells transformed by the v-H-ras, while it significantly increases the lethality with CDDP of the E1a-transformed cells. Staurosporine increases the cytoxicity of all the drugs, especially in the E1a-transformed keratinocytes. In the flow-cytometry analysis, the percentage of BUdR incorporation was related to sensitivity to anti-cancer drugs.

Functional and phenotypic analysis of T-lymphocytes in laryngeal carcinoma

We studied the functional response and phenotypic characterization of peripheral blood T cells and their correlation with the clinical stage of disease in 29 males with previously untreated carcinoma of the larynx and 24 healthy male controls. Peripheral blood T cells, phenotypically CD2+ CD3+, were significantly decreased in the patients relative to the controls. Patients with advanced locoregional extension (T4 and N1, 2, 3) also showed a diminution of the CD4+ subpopulation of T cells. DNA synthesis by purified T cells showed similar blastogenic responses in patients and controls; the interleukin-2 production of phytohemagglutinin stimulated lymphocytes was also normal. We conclude that in patients with laryngeal carcinoma there is a phenotypic alteration of the T cells that is variable according to tumor stage, without functional alterations in blastogenic capacity or IL-2 production.