Hybrid titanium dioxide/PS-b-PEO block copolymer nanocomposites based on sol-gel synthesis

The poly(styrene)-b-poly(ethylene oxide) (SEO) amphiphilic block copolymer, with two different molecular weights, has been used as a structure directing agent for generating nanocomposites of TiO(2)/SEO via the sol-gel process. SEO amphiphilic block copolymers are designed with a hydrophilic PEO-block which can interact with inorganic molecules, as well as a hydrophobic PS-block which builds the matrix. The addition of different amounts of sol-gel provokes strong variations in the self-assembled morphology of TiO(2)/SEO nanocomposites with respect to the neat block copolymer. As confirmed by atomic force microscopy (AFM), TiO(2)/PEO-block micelles get closer, forming well-ordered spherical domains, in which TiO(2) nanoparticles constitute the core surrounded by a corona of PEO-blocks. Moreover, for 20 vol% sol-gel the generated morphology changes to a hexagonally ordered structure for both block copolymers. The cylindrical structure of these nanocomposites has been confirmed by the two-dimensional Fourier transform power spectrum of the corresponding AFM height images. Affinity between titanium dioxide precursor and PEO-block of SEO allows us to generate hybrid inorganic/organic nanocomposites, which retain the optical properties of TiO(2), as evaluated by UV-vis spectroscopy.

Quantitative estimation of permeability surface-area product in astroglial brain tumors using perfusion CT and correlation with histopathologic grade

BACKGROUND AND PURPOSE

Glioma angiogenesis and its different hemodynamic features, which can be evaluated by using perfusion CT (PCT) imaging of the brain, have been correlated with the grade and the aggressiveness of gliomas. Our hypothesis was that quantitative estimation of permeability surface area product (PS), cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) in astroglial brain tumors by using PCT will correlate with glioma grade. High-grade gliomas will show higher PS and CBV as compared with low-grade gliomas.

MATERIALS AND METHODS

PCT was performed in 32 patients with previously untreated astroglial tumors (24 high-grade gliomas and 8 low-grade gliomas) by using a total acquisition time of 170 seconds. World Health Organization (WHO) glioma grades were compared with PCT parameter absolute values by using Student or nonparametric Wilcoxon 2-sample tests. Receiver operating characteristic (ROC) analyses were also done for each of the parameters.

RESULTS

The differences in PS, CBV, and CBF between the low- and high-grade tumor groups were statistically significant, with the low-grade group showing lower mean values than the high-grade group. ROC analyses showed that both CBV (C-statistic 0.930) and PS (C-statistic 0.927) were very similar to each other in differentiating low- and high-grade gliomas and had higher predictability compared with CBF and MTT. Within the high-grade group, differentiation of WHO grade III and IV gliomas was also possible by using PCT parameters, and PS showed the highest C-statistic value (0.926) for the ROC analyses in this regard.

CONCLUSIONS

Both PS and CBV showed strong association with glioma grading, high-grade gliomas showing higher PS and CBV as compared with low-grade gliomas. Perfusion parameters, especially PS, can also be used to differentiate WHO grade III from grade IV in the high-grade tumor group.

Kidney graft survival in patients with hepatitis C: a single center experience

Hepatitis C virus (HCV) infection is highly prevalent in renal transplant candidates; however, its effect on the transplant outcome is still controversial. The aim of the present study was to determine the effect of HCV infection in the outcome of kidney transplantation in a single transplant center. The study population 144 HCV- randomized selected patients and 64 HCV+ patients transplanted from 1973 to 2000, followed for up to 60 months post-transplantation. This retrospective study included the following variables: type of dialysis, time on renal replacement therapy, number of transfusions before and after transplantation, number of transplants, type of donor, immunosuppression, and rejection episodes. The Kaplan-Meier method was used to estimate graft and patient survival. Log-rank test was used to assess the difference in survival between HCV+ and HCV-. A multivariate Cox proportional hazards model was used to analyze the relation between graft and patient survival. HCV+ and HCV- patients had similar demographic and clinical characteristics; however, a higher number of HCV+ patients received blood transfusions after transplantation. Patient survival was not significantly different in 39 HCV+ and 96 HCV- patients transplanted with living-related donors (71% and 77% at five yr, respectively). Similarly, there was not significant difference in 25 HCV+ and 48 HCV- patients transplanted with kidneys from deceased donors, although there was a tendency to better outcome in HCV- patients (55% and 72% at five yr respectively). Regarding graft survival, there was also no differences in HCV+ and HCV- recipients of living-related grafts (61% and 66% at five yr post-transplant, respectively) and recipients of kidneys from deceased donors (44% and 41%, respectively). The results show that HCV+ patients can be transplanted with the same success than HCV- patients.

32 FIRST SHEEP CLONES BORN IN SOUTH AMERICA

Since the birth of the first animal produced by nuclear transfer using adult somatic cells (Wilmut et al. 1997 Nature 385, 810–813), cloning has been used in many species. Although sheep were the first species to be cloned, the limited data available from different research groups indicate sheep to be among the lowest in terms of efficiency (0.5–2%), mainly due to high losses during pregnancy and the postnatal period. Since there were no previous reports on cloning of small ruminants in South America, the aims of the present study were to perform a larger scale sheep cloning program to evaluate the efficiency under local conditions in Argentina and describe the main postmortem findings observed in fetuses and extraembrionary membranes. Male adult fibroblast cell lines from different animals were used. Matured oocytes were recovered by flushing the oviducts of synchronized and superovulated donor ewes. From 437 ewes, 4720 oocytes were recovered (10.8 oocytes/ewe). Enucleation and nuclear transfer were performed as described previously, with modifications. Cell fusion was induced by a double electrical pulse in sorbitol medium (1.20 kV cm–1, 30 μs). Fused couplets were activated using ionomycin for 5 min and then cycloheximide and cytochalasin B for 5 h. Embryo culture was performed at 38.5°C in a 5% O2, 5% CO2, 90% N2 atmosphere, in KSOM supplemented with 2% FCS and 0.2 mm glucose on Day 3 of culture. After 6 to 7 days in culture, embryos were graded and then surgically transferred into synchronized recipients. Pregnancy rate was checked 23 days after embryo transfer and then weekly until 60 days, using a transrectal 5-MHz probe (Toshiba, Tokyo, Japan). From 70 to 150 days, a 3-MHz convex probe was used to perform monthly transabdominal scans. Most of the losses (70%) occurred within the first 90 days of pregnancy, and 15% of the fetuses were aborted late in gestation. Main ultrasound findings were fetal and placental hydrops and bilateral hydronefrosis. In addition, 6 of the ewes developed hydrallantois. Ewes beyond 148 days of gestation were induced for parturition using four IM injections of betamethasone 12 h apart (3.96 mg each). If labor did not commence, a C-section was performed (9/11). Eleven cloned lambs were born; two of them are still alive (6 months). All newborns were clinically evaluated after birth and their health assessed. Of the newborns, 80% died in the first 24 h after birth; they were depressed, with severe respiratory distress that developed into acidosis. At necropsy, fetuses were found with: collapsed lungs (9/9), fatty liver (6/9), ascitis (7/9), hydronefrosis (6/9), and placental edema with partial degeneration of placentomes (8/9). The final efficiency obtained in this large-scale cloning program (0.6%) was very similar to that reported by others in a smaller trials. Many studies on gene expression of cloned embryos and placental development have partially explained why this technique has a particular low efficiency in the sheep species; therefore further studies should be done in order to improve the outcome. Table 1. Efficiency of sheep cloning

Down-regulation of bbc3, flt1 and gstm3 is associated with lymph node metastases in breast carcinoma

21171

Background: Background: Axillary lymph node metastasis is the most significant marker for the pathologic staging of breast cancer. However a proportion of lymph node-negative breast cancer will develop metastatic disease. Therefore, molecular markers of invasion in these patients are needed Methods: We selected 10 primary breast cancer cases, 5 lymph node-negative (T1N0) and 4 lymph node-positive (T1N1). In these cases we searched for gene expression of 8 genes (bbc3, cegp1, fgf18, flt1, cffm4, gstm3, hec, tgfb3) selected from previous studies as a good candidates for metastasis prediction. A quantitative Real-Time PCR was performed using beta-2- microglobulin gene expression to normalized gene expression of each gene. The expression average of beta-2-microglobulin was 303,291 among T1N0 and 342,533 among T1N1 cases (ratio 0.88). The expression average of these 8 genes was 2.11 and 0.002 at T1N0 and T1N1 respectively (ratio 1,055). At least 3 genes were significantly down-regulated in T1N1 (bbc3, flt1, gstm3) in comparison with T1N1 breast carcinomas Results: Computational analysis reveals that these 3 genes (bbc3, flt1, gstm3) contain CpG islands in their promoter regions. Although preliminary data, we found group of genes that are down-regulated in T1N1 tumor Conclusions: The finding that these genes are epigenetically regulated, suggest that could be a good candidates for metastasis prediction, by methylation approach (MethyLight System). Since this down-regulation occurs in primary tumor, the analysis of these genes might be useful to predict metastasis in lymph node-negative breast cancer.

No significant financial relationships to disclose.

365 COMPARISON OF IN VITRO FERTILIZING CAPACITY OF FROZEN - THAWED SEX-SORTED AND SEX-SORTED FROZEN - THAWED BULL SPERMATOZOA

Sperm sexing has become a world-wide technology, now available in many countries. The method has been incorporated into many reproductive technologies such as embryo production (Zhang et al. 2003 Theriogenology 60, 1657–1663), but sex-sorting is limited when bulls are located far from sorters or when only frozen semen is available. Previous studies on sexing frozen–thawed spermatozoa have been done in rams, which resulted in retention of the spermatozoan functional capacities (Hollinshead et al. 2004 Reproduction 127, 557–568). In vitro characteristics were assessed in bulls after sexing of thawed sperm (Hollinshead et al. 2004 Theriogenology 62, 958–968); however, the fertilizing capacity of frozen–thawed sex-sorted (FTSS) spermatozoa was not tested. The aim of the present study was to compare cleavage and embryo development rate among frozen–thawed (FT), sex-sorted frozen–thawed (SSFT), and FTSS bull spermatozoa. For FT, sperm were diluted to a final concentration of 60 × 106 sperm/mL, packaged in 0.5-mL straws, and frozen. In SSFT, spermatozoa were sex-sorted by flow cytometry following Schenk protocols (1999 Theriogenology 52, 1375–1391). Three × 106 spermatozoa were packaged into 0.25-mL straws and frozen. The final treatment (FTSS) consisted of thawing 6 to 10 frozen straws of 4 different bulls containing an average of 25 × 106 spermatozoa and centrifuging at 600g for 15 min at 21°C to extract cryodiluent. Spermatozoa were diluted and stained with Hoechst 33342 (stain concentration of 112.5 µM, the same used for SSFT treatment) following Schenk sexed-semen protocols (1999), sex-sorted by a flow cytometer, and collected in Tris-base extender containing 20% egg yolk. For each ejaculate frozen–thawed, SSFT and FTSS spermatozoa were prepared for oocyte in vitro fertilization. Also, semen from a bull routinely used as a control in the laboratory was added for a better comparison of results. Oocytes from a slaughterhouse were processed following standard in vitro fertilization procedures (Ferré 2002 Theriogenology 57, 664) 4 times for each bull, and comparison was made between treatments. Results were analyzed by ANOVA. No significant differences were observed among bulls (data not shown) (P > 0.05). Although embryo development rate was statistically different between sexed and non-sexed groups (P < 0.05), results showed that frozen–thawed bull spermatozoa can be sex-sorted and used for in vitro fertilization with comparable developmental rates comparable to those when frozen sexed semen is used (Table 1). This opens a new commercial window for cases where pre-selected sexed embryos from bulls that are not in AI centers are desired, also giving an opportunity for dead bulls. Nevertheless, since a large number of straws are necessary, further studies must be carried out to make this procedure more efficient and economically profitable. Table 1. Results of cleavage and embryo development rates between spermatozoa treatments

Docetaxel (T) given concurrently with or sequentially to anthracycline-based (A) adjuvant therapy (adjRx) for patients (pts) with node-positive (N+) breast cancer (BrCa), in comparison with non-T adjRx: First results of the BIG 2–98 Trial at 5 years median follow-up (MFU)

LBA519

Background: The activity of T in metastatic BrCa mandated evaluation as adjRx. We compared the efficacy of T with, or after A, both followed by CMF (cyclophosphamide/ methotrexate/ 5-fluorouracil), versus non-T adjRx. Methods: Random assignment trial in resected N+ pts, 18–70 yrs, stratified by: center, 1–3 vs >3 nodes and age <50 vs ≥50. The treatment arms were (mg/m2, intravenously unless otherwise stated): Ia: A 75 q 3 weeks × 4 ⋄ CMF ×3 (oral C 100 day 1–14, F 600 + M 40 d 1+8; q 28 days). Arm Ib; AC 60/600 × 4⋄CMF × 3. Arm II: A75 × 3 ⋄T100 ×3 ⋄CMF ×3. Arm III: AT 50/75 ×4 ⋄ CMF × 3. Pts subsequently received hormono-(receptor+), and radiotherapy per local guidelines. Randomization was in the ratio (1:1:2:2). The trial was designed to have 80% power to detect a 78% hazard ratio (HR) for relapse in II+III v I, with final analysis at 1215, and interim at 405 and 810 events. The primary comparison between the II+III and I would be done at a one-tailed significance level of 0.025. Secondary comparisons of II vs Ia and III vs Ib would be done using a closed testing procedure at a one-tailed significance level of 0.025. The 95% confidence limits of the HR of III v II would be calculated. Due to a low relapse rate, the plan was amended with main analysis after 810 events or 5 years MFU. Results: 2887 pts were enrolled (6/1998–6/2001). Characteristics were well-balanced, 46% had >3N+. Grade 3/4 toxicity occurred in 22.9, 24.7, 35.3 and 28.6 % of pts in Ia, Ib, II and III respectively. At 62.2 months MFU (3/2006), 732 pts (25%) had events. Planned event-free survival (EFS) comparisons were: Conclusion: In this study, the HR for T v non-T adjRx was of borderline significance. There were possibly important differences related to schedule, sequential but not concurrent appearing superior to non-T adjRx. Overall survival analysis will require longer follow-up. Translational studies are underway.

[Table: see text] [Table: see text]

Nonesophageal side-effects after antireflux surgery plus acid-suppression duodenal diversion surgery in patients with long-segment Barrett's esophagus*

During the last years we have employed acid-suppression duodenal diversion procedures (truncal vagotomy-partial gastrectomy plus Roux-en-Y gastrojejunostomy) in addition to antireflux surgery in order to treat all the pathophysiological factors involved in the genesis of Barrett's esophagus. We have observed very good results concerning the clinical and objective control of GERD at the long-term follow up after this procedure. However, it could be associated with other nonesophageal symptoms or side-effects. This study was conducted to evaluate the presence of gastrointestinal symptoms (diarrhea, vomiting, dumping, weight loss and anastomotic ulcers) after this operation. In this prospective study 73 patients were assessed using a careful clinical questionnaire asking regarding these complications at the early (< 6 months) and late (> 6 months) follow-up (average of 32.4 months). In the early postoperative period, diarrhea was present in 64% (19% considered severe 10-90 days after surgery), dumping in 41% and loss of weight in 71% of cases. Diarrhea occurred daily in 47.7% in the early postoperative period, but only in 16% of cases after 1 year. Shortly after surgery, steatorrea was observed in 9% of cases and responded well to medical treatment. Severe diarrhea or dumping was rare (5% of cases). These symptoms improved significantly after 1 year with medical management (45%, 20% and 30%, respectively) and 42% of patients regained their normal body weight. Only two patients presented anastomotic ulcers and were treated satisfactory with proton pump inhibitors. Revisional surgery was indicated in two patients with severe dumping syndrome. Most side-effects identified by this study were mild and diminished 1 year after operation.

49 EFFECT OF REPEATED CELL FREEZINGS ON PREGNANCY RATE OF BOVINE NUCLEAR TRANSFER DERIVED EMBRYOS

Cell line cryopreservation is nowadays one of the most useful tools in somatic cell nuclear transfer. Although this technique guarantees the genetic storage for an unlimited period of time, many studies have shown that it produces different kinds of cellular damage such as DNA fragmentation (Men et al. 2003 Mol. Reprod. Dev. 64, 245–250) and ultrastructural cell anomalies (Taddei et al. 2001 Cryobiology 42, 244–555; Nardid et al. 1997 Cryobiology 34, 107–113). The aim of the present study was to evaluate how repeated cell freezing/thawing processes could affect the pregnancy rate of bovine nuclear transfer-derived embryos. Two adult fibroblast cell lines from different animals were separated into two groups according to the number of freezing/thawing processes they went through (1 vs. 3). For both groups, the first freezing process was performed with cells from passage 1. Cells from passages 3 and 4 were used for the second and third freezings, respectively. The time interval between thawing and next freezing was 20 days. Cells were harvested at 80% confluence using trypsin, and cryopreservation was performed in D-MEM with 35% FCS and 10% DMSO. Enucleation and nuclear transfer (NT) were performed as described by Cibelli et al. (1998 Science 280, 1256–1258) with modifications. For both groups, cells from the same number of passages were used for the NT assays (between passages 2 and 7). Cytoplasts were activated using 5 μM ionomycin for 4 min and the couplets were subsequently fused. The fused units were cultured in 10 μg/mL cycloheximide and 5 μg/mL cytochalasin B for 6 h. Embryo culture was performed at 38.5°C in a 5% O2, 5% CO2, 90% N2 atmosphere, in 50-μL drops of KSOM. On Day 3 of culture, the KSOM was supplemented with 2% FCS and 0.2 mM glucose. After 6–7 days, the embryos were non surgically transferred to synchronized recipients. Pregnancy at 30 and 60 days was recorded by ultrasonography using an Aloka 500® scanner (Aloka Co., Tokyo, Japan). Data were analyzed by ANOVA (InfoStat, Austin, TX, USA) (Table 1). The results show an association between the number of cell freezing/thawing processes and a higher pregnancy loss at 60 days. This could be related to the cellular damages caused by multiple cryopreservation procedures, which could lead to chromosomal abnormalities in the donor cells and thus in the nuclear transfer (NT) embryos and pregnancies derived from them. Further studies should be done in order to evaluate the chromosomal status of the cell lines used in this work. Table 1. Numbers of cell freezings/thawings and their effect on pregnancy rate of bovine NT-derived embryos

161 PREGNANCY RATES OBTAINED AFTER EMBRYO TRANSFER AT FIXED TIME OF IN VIVO-, IVF- AND CLONED-DERIVED EMBRYOS

The most important factor in bovine embryo transfer programs is the low efficiency in the utilization of the recipients; this low efficiency is associated with low response to synchronization protocols and failures in estrus detection. It has been shown that cows transferred at fixed time with in vivo-derived embryos resulted in high rates of recipients selected for transfer and high overall pregnancy rates (recipients pregnant/recipients treated) (Tribulo et al. 2002 Theriogenology 57, 563). An experiment was designed to evaluate the pregnancy rate in recipients transferred with in vivo (fresh and frozen), IVF, and cloned-derived embryos without estrus detection. A total of 1555 non-lactating Bos Taurus crossbred beef cows was divided into two groups. Cows from group 1 (n = 421) were synchronized with a progesterone intravaginal releasing device (1 g P4; DIB, Syntex®, Buenos Aires, Argentina) plus 2 mg of estradiol benzoate (EB) i.m. (Syntex®) on Day 0. On Day 5, they received 400 IU of eCG (Novormon 5000, Syntex®) i.m. and 150 μg of D-Cloprostenol (PGF2α) (Bioprost-D, Biotay®, Buenos Aires, Argentina). The DIB devices were removed on Day 8 and on Day 9, 1 mg of EB was injected. Day 10 was arbitrarily considered as the day of estrus. Cows from group 2 (n = 1134) received 2 doses of PGF2α 14 days apart and were checked for heat during 5 days after the second PGF2α dose. Cows of both groups were examined 7 days after estrus by ultrasonography (Pie Medical Scanner 200®) and those with a corpus luteum >10 mm of diameter were transferred nonsurgically with in vivo (fresh and frozen), IVF, and cloned-derived embryos. In group 1, 360 cows were transferred, and in group 2, 726 cows were transferred (Table 1). Pregnancy was diagnosed 23 days later by ultrasonography (Pie Medical Scanner 200®). The pregnancy rates were compared statistically between groups 1 and 2 by analysis of variance (Infostat, LSD Fisher). There was no significant statistic difference (P > 0.05) between pregnancy rate in group 1 and 2 with in vivo (fresh), IVF, and cloned-derived embryos. However, pregnancy rate of frozen in vivo-derived embryos was lower in group 1 than in group 2 (P < 0.05). Results showed that treatment using DIB combined with EB, PGF2α, and eCG associated with embryo transfer without estrus detection (group 1) had no difference in pregnancy rate when compared with the treatment where synchronization with PGF2α and heat detection were used (group 2). Another important advantage is the use the group 1 treatment for increasing the flexibility and efficiency in the management of the recipients of in vivo, IVF, and cloned-derived embryo transfer programs. Table 1. Comparison of pregnancy rates between group 1 (embryo transfer at fixed time) and group 2 (embryo transfer 7 days after estrus detection)

Activity of rifampin against Mycobacterium tuberculosis in a reference center

Rifampin is a bactericidal antibiotic that acts both on extra- and intracellular bacilli. It inhibits RNA synthesis by binding to the beta-subunit in the RNA polymerase. A study was conducted on rifampin resistance from 1993 to 2002 with 1,794 Mycobacterium tuberculosis strains submitted to Mycobacteria Reference Center, Córdoba, Spain. A total of 1,460 of these strains came from pulmonary specimens and 235 from extrapulmonary specimens. All strains were identified by conventional morphological, bacteriological, biochemical, genetic, and chromatographic methods. For 99 strains, the source was not indicated. Initially, the BACTEC 460 TB system was used for antibiotic sensitivity testing. Since 1996, the ESP II system was also used. The strains ATCC27294 (sensitive to streptomycin, rifampin, ethambutol, and isoniazid) and ATCC38838 (resistant to rifampin) were used as controls. The resistance degree detected was 10.03%, of which 1.2% and 8.7% corresponded to primary and secondary resistances, respectively. A total of 137 strains showed multiresistance. The surveillance of resistance and of the potential factors that may lead to an increase in resistance is thus warranted.

Chromosomal abnormalities in fetuses with open neural tube defects: prenatal identification with ultrasound

OBJECTIVES

To determine the prevalence of chromosomal abnormalities in fetuses with open neural tube defects (NTD) undergoing prenatal chromosome analysis. The role of prenatal ultrasound in detecting those with an underlying chromosomal abnormality was also investigated.

METHODS

Over a 6-year period, 144 fetuses with open NTD underwent prenatal chromosome analysis between 12 and 37 weeks of gestation, as part of a prospective, multicenter prenatal diagnosis and counseling program in Chile. This population included 66 fetuses with spina bifida, 46 with acrania/anencephaly, 21 with cephalocele and 11 with iniencephaly. A confident prenatal diagnosis was made in 143 fetuses (99%) and confirmed postnatally in all cases.

RESULTS

An underlying chromosomal abnormality was diagnosed in 10 fetuses (7%), six with spina bifida, three with cephalocele and one with craniorachischisis. The prevalence of chromosomal abnormality varied according to the defect present in the fetus, with a 14% (3/21) prevalence among those with cephalocele, 9% (6/66) among those with spina bifida and 2% (1/57) among those with lethal defects such as acrania, anencephaly or iniencephaly. Karyotype results revealed trisomy 18 in seven cases, trisomy 13 in two and mosaicism for a marker chromosome in one. Prenatal ultrasound before the procedure showed that all chromosomally abnormal fetuses had additional findings. The prevalence of chromosomal abnormality in fetuses with spina bifida and cephalocele was higher when chromosome analysis was performed at or before 24 weeks of gestation in comparison to those performed after 24 weeks (5/31 (16%) vs. 4/56 (7%), respectively). However, this difference did not reach statistical significance, probably due to the small number of cases.

CONCLUSIONS

A significant number of fetuses with open NTD are chromosomally abnormal. Although prenatal chromosome analysis should be considered in all cases, prenatal ultrasound seems effective in identifying those fetuses with an underlying chromosomal abnormality.

GenoType mycobacterium assay for identification of mycobacterial species isolated from human clinical samples by using liquid medium

The GenoType Mycobacterium assay was used to identify 98 mycobacteria isolates by using liquid cultures from positive BACTEC, MGIT, and ESP bottles. This system identifies 16 mycobacteria. There was complete agreement between the GenoType results and the laboratory identifications for Mycobacterium tuberculosis complex and other Mycobacterium spp. GenoType also identified mixed mycobacterial infections.

High blood pressure and decreased heart rate variability in the Cuban epidemic neuropathy

Autonomic cardiovascular reflexes were investigated in patients with an epidemic optic and peripheral neuropathy, which affected more than 50 000 people in Cuba between 1991 and 1994 and was probably caused by nutritional deficiency. Affected patients had significantly higher blood pressure than age matched controls, both while supine and standing, and significantly lower heart rate variability during paced breathing, suggesting reduced cardiac parasympathetic innervation.

Epstein-Barr virus latent membrane protein-1 (LMP-1) expression in oral squamous cell carcinoma

OBJECTIVES

Epstein-Barr virus (EBV) is frequently associated with malignant cell transformation through the action of the oncoprotein latent membrane protein-1 (LMP-1). The present study aimed to determine the presence of EBV in oral squamous cell carcinomas (OSCCs) and the expression of LMP-1 in neoplastic cells of EBV-positive OSCCs.

STUDY DESIGN/METHODS

In a retrospective study of 78 OSCCs, we investigated the presence of the DNA of EBV by polymerase chain reaction, the expression of the oncoprotein LMP-1 by immunohistochemistry, and the presence of EBV-encoded RNA (EBER) by in situ hybridization.

RESULTS

EBV DNA was detected in 19.2% of the cases. Expression of LMP-1 in neoplastic cells was found in 85.7% of the EBV-positive OSCCs. EBV presence was significantly more frequent (P <.05) in OSCCs localized on the lateral tongue. EBV-positive OSCCs more frequently presented (P <.05) greater nuclear atypia.

CONCLUSION

EBV can appear in latent form in OSCC and express its main oncoprotein, LMP-1.

Higher risk of preterm birth and low birth weight in women with periodontal disease

Pregnant women with periodontal disease (PD) may be at increased risk for having preterm low-birth-weight (PLBW) children. We investigated whether the maintenance of the mothers' periodontal health after 28 weeks' gestation reduces the risk of PLBW. Of the 639 women studied, 406 had gingivitis and received treatment before 28 weeks' gestation, and 233 had PD and were treated after delivery. Data about previous and current pregnancies and known risk factors were obtained from patients' medical records. Primary outcomes were delivery before 37 weeks' gestation or an infant with birth weight below 2500 g. The incidence of PLBW was 2.5% in periodontally healthy women, and 8.6% in women with PD (p = 0.0004, relative risk = 3.5, 95% CI, 1.7 to 7.3). Risk factors significantly associated with PLBW were previous PLBW, PD, fewer than 6 pre-natal visits, and low maternal weight gain. PD was associated with both preterm birth and low birth weight, independent of other risk factors.