Putative Mechanisms of Viral Transmission and Molecular Dysregulation of Mammary Epithelial Cells by Human Papillomavirus: Implications for Breast Cancer.

Breast cancer is the most common cancer in women worldwide. Several studies have demonstrated the presence of Human papillomavirus (HPV) DNA in breast cancer samples. However, the role of HPV in breast carcinogenesis is not clear, and the interaction mechanisms between this infectious agent and the breast cancer cell need to be more fully clarified. In this article, we discuss the putative roles of HPV infection in breast carcinogenesis.

Development of a DNA-based vaccine strategy against bovine papillomavirus infection, involving the E5 or L2 gene.

Papillomaviruses are known to cause tumor lesions, generally benign, in epithelial tissues of diverse organisms; these lesions may progress to cancer under suitable conditions. Bovine papillomavirus (BPV) can cause urinary bladder cancer and cancer of the upper gastrointestinal tract. Furthermore, BPV1 and BPV2 are implicated in the development of tumors in equids. Many studies with animal models clearly demonstrate that DNA vaccines are very effective tools in controlling viral infections, providing strong humoral and cellular immune responses. In this study, we have described the development of two vaccine constructs for the control of diseases caused by BPV. The 1st strategy is prophylactic and is based on the L2 gene; the 2nd is therapeutic and is based on the E5 gene. Vaccine constructs were obtained and evaluated in vitro in mammalian cells. The results show the occurrence of E5 and L2 transcription and viral protein production. These results confirm the functionality of the vaccine constructs in mammalian cells. This is the 1st step in the development of a DNA-based vaccine strategy for the control and/or treatment of diseases caused by BPV.

Bonding of Y-TZP to dentin: effects of Y-TZP surface conditioning, resin cement type, and aging.

PURPOSE: To evaluate the effects of two surface treatments, aging, and two resin cements on shear bond strength between dentin and yttrium-stabilized tetragonal zirconia polycrystal ceramic (Y-TZP). MATERIALS AND METHODS: Eighty human molars were embedded in acrylic resin and sectioned 3 mm below the occlusal plane. These teeth and 80 cylindrical Y-TZP specimens (height, 4 mm; diameter, 3.4 mm) were divided into eight groups (n=10) using the following factors: Y-TZP surface treatment (Vi: low-fusing porcelain [vitrification] + hydrofluoric acid etching + silanization or Si: tribochemical silicatization); cementation strategies (PF: Panavia or CC: Clearfil); and storage (nonaging or aging). Bonding surfaces of 40 Y-TZP specimens received Vi treatment, and the rest received Si treatment. Half of the ceramic-tooth assemblies were cemented with Panavia, the rest with Clearfil. Shear tests were executed using 0.4-mm-thick wire at 0.5 mm/min. Data were analyzed by three-way analysis of variance and Tukey test (α=0.05). Fractures were analyzed. RESULTS: Y-TZP surface treatments did not affect bond strength (p=0.762, Vi = Si), while resin cements (p<0.001, Panavia > Clearfil) and aging (p=0.006, nonaging > aging) showed a significant effect. Most failures were in adhesive at dentin-cement interfaces; no failure occurred between zirconia and cement. CONCLUSION: When Y-TZP ceramic is bonded to dentin, the weakest interface is that between dentin and resin cement. The resin cement/Y-TZP interface was less susceptible to failures, owing to Y-TZP surface treatments.

Detection of the dengue non-structural 1 antigen in cerebral spinal fluid samples using a commercially available enzyme-linked immunosorbent assay.

The involvement of the central nervous system in dengue infections has been reported in countries where the disease in endemic. The purpose of this study was to determine whether an enzyme-linked immunosorbent assay kit designed to detect the dengue NS1 antigen in serum was able to detect this antigen in cerebral spinal fluid (CSF) samples from patients with fatal outcomes. To evaluate the sensitivity of the kit, 26 dengue-positive CSF samples were used. The Pan-E Dengue Early kit was able to detect the NS1 antigen in 13 of 26 dengue-positive CSF samples, resulting in a sensitivity of 50% (95% confidence interval, 29.9-70.1%) and specificity of 100% (95% confidence interval, 75.3-100%). The kit was able to detect the NS1 antigen in CSF of individuals who had died of dengue. When used in combination with IgM, the detection rate rose to 92.3%. This study reports a method for rapidly detecting the dengue virus in CSF, thereby increasing the diagnosis of dengue fever cases with unusual neurological manifestations.

Influence of decreasing nutrient path length on the development of engineered cartilage.

OBJECTIVE: Chondrocyte-seeded agarose constructs of 4mm diameter (2.34 mm thickness) develop spatially inhomogeneous material properties with stiffer outer edges and a softer central core suggesting nutrient diffusion limitations to the central construct region [Guilak F, Sah RL, Setton LA. Physical regulation of cartilage metabolism. In: Mow VC, Hayes WC, Eds. Basic Orthopaedic Biomechanics, Philadelphia 1997;179-207.]. The effects of reducing construct thickness and creating channels running through the depth of the thick constructs were examined. METHODS: In Study 1, the properties of engineered cartilage of 0.78 mm (thin) or 2.34 mm (thick) thickness were compared. In Study 2, a single nutrient channel (1 mm diameter) was created in the middle of each thick construct. In Study 3, the effects of channels on larger 10 mm diameter, thick constructs were examined. RESULTS: Thin constructs developed superior mechanical and biochemical properties than thick constructs. The channeled constructs developed significantly higher mechanical properties vs control channel-free constructs while exhibiting similar glycosaminoglycan (GAG) and collagen content. Collagen staining suggested that channels resulted in a more uniform fibrillar network. Improvements in constructs of 10 mm diameter were similarly observed. CONCLUSIONS: This study demonstrated that more homogeneous tissue-engineered cartilage constructs with improved mechanical properties can be achieved by reducing their thickness or incorporating macroscopic nutrient channels. Our data further suggests that these macroscopic channels remain open long enough to promote this enhanced tissue development while exhibiting the potential to refill with cell elaborated matrix with additional culture time. Together with reports that <3 mm defects in cartilage heal in vivo and that irregular holes are associated with clinically used osteochondral graft procedures, we anticipate that a strategy of incorporating macroscopic channels may aid the development of clinically relevant engineered cartilage with functional properties.

Mechanical and biochemical characterization of cartilage explants in serum-free culture.

Allografts of articular cartilage are both used clinically for tissue-transplantation procedures and experimentally as model systems to study the physiological behavior of chondrocytes in their native extracellular matrix. Long-term maintenance of allograft tissue is challenging. Chemical mediators in poorly defined culture media can stimulate cells to quickly degrade their surrounding extracellular matrix. This is particularly true of juvenile cartilage which is generally more responsive to chemical stimuli than mature tissue. By carefully modulating the culture media, however, it may be possible to preserve allograft tissue over the long-term while maintaining its original mechanical and biochemical properties. In this study juvenile bovine cartilage explants (both chondral and osteochondral) were cultured in both chemically defined medium and serum-supplemented medium for up to 6 weeks. The mechanical properties and biochemical content of explants cultured in chemically defined medium were enhanced after 2 weeks in culture and thereafter remained stable with no loss of cell viability. In contrast, the mechanical properties of explants in serum-supplemented medium were degraded by ( approximately 70%) along with a concurrent loss of biochemical content (30-40% GAG). These results suggest that long-term maintenance of allografts can be extended significantly by the use of a chemically defined medium.

The beneficial effect of delayed compressive loading on tissue-engineered cartilage constructs cultured with TGF-beta3.

OBJECTIVE: To determine whether the functional properties of tissue-engineered constructs cultured in a chemically-defined medium supplemented briefly with TGF-beta3 can be enhanced with the application of dynamic deformational loading. METHODS: Primary immature bovine cells (2-3 months old) were encapsulated in agarose hydrogel (2%, 30 x 10(6)cells/ml) and cultured in chemically-defined medium supplemented for the first 2 weeks with transforming growth factor beta 3 (TGF-beta3) (10 microg/ml). Physiologic deformational loading (1 Hz, 3 h/day, 10% unconfined deformation initially and tapering to 2% peak-to-peak deformation by day 42) was applied either concurrent with or after the period of TGF-beta3 supplementation. Mechanical and biochemical properties were evaluated up to day 56. RESULTS: Dynamic deformational loading applied concurrently with TGF-beta3 supplementation yielded significantly lower (-90%) overall mechanical properties when compared to free-swelling controls. In contrast, the same loading protocol applied after the discontinuation of the growth factor resulted in significantly increased (+10%) overall mechanical properties relative to free-swelling controls. Equilibrium modulus values reach 1306+/-79 kPa and glycosaminoglycan levels reach 8.7+/-1.6% w.w. during this 8-week period and are similar to host cartilage properties (994+/-280 kPa, 6.3+/-0.9% w.w.). CONCLUSIONS: An optimal strategy for the functional tissue engineering of articular cartilage, particularly to accelerate construct development, may incorporate sequential application of different growth factors and applied deformational loading.

Renal morphometry of fetuses rats treated with cadmium

El cadmio es un metal pesado que se encuentra en la tierra, aire y alimentos. Está presente en forma coditiana todos los días de la vida y actualmente es catalogado como un tóxico, teratogénico y agente carcinogénico. El cadamio causa numerosas lesiones a los órganos humanos y animales. Este trabajo tiene como objetivo investigar los efectos tóxicos en fetos de ratas expuestas a tratamiento con cloruro de cadmio. 10 ratas pre¤adas fueron divididas en dos grupos. Cinco ratas recibieron por administración intraperitoneal 5 mg/Kg de cloruro de cadmio por peso corporal, durante 10 días de pre¤ez y otras cinco ratas recibieron bajo las mismas condiciones del otro grupo, una solución de cloruro de sodio al 0.85 por ciento . Los fetos fueron extraídos junto con las placentas y funículos umbilicales a los 20 días de pre¤ez. La administración del cloruro de cadmio causó una reducción significativa en los pesos de los fetos y placentas. La longitud del funículo umbilical fue más corta en el grupo experimental que en el grupo control. El estudio evaluó las alteraciones morfológicas causadas en los túbulos proximal, distal, contorneados y colectores renales como también en las células del glomérulo renal. La morfometría evidenció alteraciones significativas en los túbulos proximales y en las células glomerulares y, en menor grado, en los túbulos distales. El borde en cepillo de la membrana celular se observó muy sensible y se visualizaron algunas alteraciones. Los glomérulos se presentaron con edema y la cápsula del glomérulo fue también afectada.

Ambulatory blood pressure and Doppler echocardiographic indexes of borderline hypertensive men presenting an exaggerated blood pressure response during dynamic exercise.

Borderline hypertension (BH) has been associated with an exaggerated blood pressure (BP) response during laboratory stressors. However, the incidence of target organ damage in this condition and its relation to BP hyperreactivity is an unsettled issue. Thus, we assessed the Doppler echocardiographic profile of a group of BH men (N = 36) according to office BP measurements with exaggerated BP in the cycloergometric test. A group of normotensive men (NT, N = 36) with a normal BP response during the cycloergometric test was used as control. To assess vascular function and reactivity, all subjects were submitted to the cold pressor test. Before Doppler echocardiography, the BP profile of all subjects was evaluated by 24-h ambulatory BP monitoring. All subjects from the NT group presented normal monitored levels of BP. In contrast, 19 subjects from the original BH group presented normal monitored BP levels and 17 presented elevated monitored BP levels. In the NT group all Doppler echocardiographic indexes were normal. All subjects from the original BH group presented normal left ventricular mass and geometrical pattern. However, in the subjects with elevated monitored BP levels, fractional shortening was greater, isovolumetric relaxation time longer, and early to late flow velocity ratio was reduced in relation to subjects from the original BH group with normal monitored BP levels (P<0.05). These subjects also presented an exaggerated BP response during the cold pressor test. These results support the notion of an integrated pattern of cardiac and vascular adaptation during the development of hypertension.

Ambulatory blood pressure and Doppler echocardiographic indexes of borderline hypertensive men presenting an exaggerated blood pressure response during dynamic exercise

Borderline hypertension (BH) has been associated with an exaggerated blood pressure (BP) response during laboratory stressors. However, the incidence of target organ damage in this condition and its relation to BP hyperreactivity is an unsettled issue. Thus, we assessed the Doppler echocardiographic profile of a group of BH men (N = 36) according to office BP measurements with exaggerated BP in the cycloergometric test. A group of normotensive men (NT, N = 36) with a normal BP response during the cycloergometric test was used as control. To assess vascular function and reactivity, all subjects were submitted to the cold pressor test. Before Doppler echocardiography, the BP profile of all subjects was evaluated by 24-h ambulatory BP monitoring. All subjects from the NT group presented normal monitored levels of BP. In contrast, 19 subjects from the original BH group presented normal monitored BP levels and 17 presented elevated monitored BP levels. In the NT group all Doppler echocardiographic indexes were normal. All subjects from the original BH group presented normal left ventricular mass and geometrical pattern. However, in the subjects with elevated monitored BP levels, fractional shortening was greater, isovolumetric relaxation time longer, and early to late flow velocity ratio was reduced in relation to subjects from the original BH group with normal monitored BP levels (P<0.05). These subjects also presented an exaggerated BP response during the cold pressor test. These results support the notion of an integrated pattern of cardiac and vascular adaptation during the development of hypertension

Antierythrocyte antibodies in hemodialysis and kidney transplant patients.

Natural antierythrocytic antibodies may be stimulated by bacterial antigens and the immune type may occur as a result of pregnancy or blood transfusions. The prevalence increases with the number of red cell units transfused. Specificity, on the other hand, depends on ethnic backgrounds. The clinical importance of these antibodies is to precipitate hemolytic transfusion reactions and erythroblastosis fetalis. Hemodialysis patients are multitransfused and have a quite variable prevalence of antibodies. Kidney transplant patients with blood group identity do not form antibodies. We studied the presence of both types of antierythrocytic antibodies (natural and immune) in hemodialysis and kidney transplant patients in Brazilian blood transfusion and nephrology services.

[Ambulatory blood pressure monitoring in individuals with exaggerated blood pressure response to exercise. Influence of physical conditioning]. / Monitorização ambulatorial da pressão arterial em indivíduos com resposta exagerada dos Níveis pressóricos em Esforço. Influência do condicionamento físico.

PURPOSE: To evaluate the effects of exercise training on ergometric test and ambulatory blood pressure monitoring (ABPM) in normotensive individuals with exaggerated blood pressure response to exercise. METHODS: We studied 22 sedentary and normotensive subjects (mean 44 +/- 1 years old) showing an exaggerated systolic blood pressure response (SBP > 220mmHg) during a cycloergometric test. These individuals were divided in two groups: sedentary hyperreactive group (SHG) and trained hyperreactive group (THG). The THG was submitted to a 4 month aerobic exercise training program. RESULTS: A program of moderate aerobic exercise did not reduce (P > 0.05) ABPM blood pressure levels. However, in the submaximal loads of dynamic exercise we observed a significant fall in the SBP and heart rate (P < 0.05) CONCLUSION: Normotensive individuals with exaggerated blood pressure response to dynamical exercise submitted to physical training presented a reduction in their systolic blood pressure and heart rate response during the submaximal loads of the cycloergometric test. The ABPM blood pressure values, however, did not change in both groups. These results suggest the involvement of the sympathetic nervous system in the exaggerated blood pressure response observed in these individuals during dynamic exercise and a corresponding reduction of the sympathetic tonus after training. This effect, apparently, did not extend to their daily activities.

Doppler echocardiographic indexes and 24-h ambulatory blood pressure data in sedentary middle-aged men presenting exaggerated blood pressure response during dynamical exercise test.

Previous studies have pointed out that exaggerated blood pressure (BP) response during physical exercise could be an early marker of essential hypertension. Apparently some of the exaggerated BP responders present changes in the heart geometry and function that are usually found in the early course of the hypertensive disease. To evaluate the association between exaggerated BP response and these changes, we submitted 20 normotensive men presenting elevated BP response during bicycle exercise (hyperreactive group, systolic BP > or = 220 mmHg at maximal workload) to 24-h ambulatory blood pressure monitoring (ABPM) and to two-dimensionally guided M-mode echocardiography and pulsed Doppler. The results from this group were contrasted with those of a comparable group, which otherwise, presented normal BP response during the same procedure (control group, systolic BP < or = 210 mmHg at maximal workload). The ABPM measurements were normal and analogous between the two groups: the mean 24-h systolic blood pressure (SBP) was respectively 126 +/- 6 mmHg and 129 +/- 5 mmHg, diastolic blood pressure (DBP) 82 +/- 4 mmHg in both groups, and heart rate (HR), respectively 76 +/- 9 and 74 +/- 7 bpm. The univariate correlation (R) between the maximal BP response during bicycle exercise and BP measurements in the ABPM were in general weak, and as a whole, the hyperreactive group presented the weakest correlation coefficients. M-mode echocardiographic data such as the left ventricular mass index (LVMI, 80 +/- 10 vs. 81 +/- 11 g/m2), posterior wall and interventricular septal thickness (PWT, 8.8 +/- 0.6 vs. 8.6 +/- 0.7 mm; IVST, 9.0 +/- 0.4 vs. 8.8 +/- 0.6) were also normal and comparable between the groups. LV systolic functional indexes such as fractional shortening (LVFS, 39 +/- 2.8 vs. 40 +/- 3.5%) and ejection fraction (LVEF, 70 +/- 3.5 vs. 71 +/- 3.7%) were also normal and similar. Doppler-derived LV diastolic functional indexes such as the peak velocity of early flow divided by the peak velocity of late flow (RE/A) and isovolumetric relaxation time (IVRT) were also equivalent (RE/A, both 1.3 +/- 0.2, IVRT 79 +/- 7 vs. 81 +/- 6 msec). These results support the concept that an exaggerated BP elevation during physical activity, when not accompanied of higher levels of BP during daily activities are not associated with changes in the heart geometry or in the ventricular function, and might represent an hemodynamical behavior of limited pathological and clinical importance. These conclusions must be taken cautiously since personal characteristics such as life style, family history of hypertension, gender, race and also the levels of BP chosen to delimit a normal and an exaggerated BP response might be important factors determining the consequences of the hyperreactive behavior.

Monitoraçäo da leucose enzoótica bovina no gado leiteiro da regiäo de Pitangueiras (SP) / Monitoring of enzootic bovine leukosis in dairy cattle from the Pitangueiras region in Sao Paulo, Brazil

Anticorpos precipitantes contra o antígeno gp51 do vírus da Leucose Enzoótica Bovina foram pesquisados em amostras de soros de vacas leiteiras da regiäo do Município de Pitangueiras, no Estado de Säo Paulo. As amostras sanguíneas eram de animais provenientes de sete propriedades rurais que foram acompanhadas anualmente de 1992 até 1995. Durante o ano de 1992 foram analisados 140 soros, dos quais 24 (17,1 por cento) eram reagentes positivos, 21 (15,0 por cento) suspeitos e 95 (67,9 por cento) negativos. Em 1993, dos 122 soros testados, 25 (20,5 por cento) foram positivos, 8 (6,6 por cento) suspeitos e 89 (72,9 por cento) negativos. No ano de 1994 foram testadas 135 amostras, das quais 45 (33,3 por cento) eram positivas, 19 (14,1 por cento) suspeitas e 71 (52,6 por cento) negativas. Finalmente, em 1995, foram analisadas as amostras de 119 animais sendo que 60 (50,4 por cento) eram positivas, 11 (9,2 por cento) suspeitas e 48 (40,4 por cento) negativas. Os resultados obtidos evidenciam que no decorrer do experimento houve um nítido aumento na prevalência da Leucose Enzoótica Bovina com o passar do tempo. Sob o prisma da Defesa Sanitária Animal, a crescente disseminaçäo da doença na populaçäo estudada serve como alerta sobre o comportamento epidemiológico e sobre a evoluçäo na difusäo da enfermidade em nosso meio

[Blood pressure assessment in normoreactive and hyperreactive patients. A comparative study between casual and ambulatory blood pressure monitoring]. / Avaliação da pressão arterial em indivíduos normais e hiper-reatores. Um estudo comparativo dos métodos de medidas casual e da MAPA.

PURPOSE: To evaluate the levels of blood pressure when measured by casual and ambulatory blood pressure monitoring. METHODS: We studied 16 sedentary and normotensive subjects (mean 43 +/- 3 years old) showing an exaggerated blood pressure response (SBP > 220 mmHg) during a cycloergometric test, hyperreactive group (HG). This group was compared to 15 others with SBP < or = 220 mmHg during exercise, normoreactive group (NG). Casual blood pressure was obtained by the conventional method and the ambulatory blood pressure monitoring (ABPM) was obtained with SpaceLabs 90207 monitor. This procedure (test 1) was repeated after four months (test 2). RESULTS: Both groups showed statistically higher levels of blood pressure when measured by ABPM device, compared to casual measurements. Systolic blood pressure was significantly higher in HG in casual measurement, in test 1 but not in test 2. Diastolic blood pressure was significantly higher in HG only through the ABPM device. The ambulatory blood pressure average values for two or 24 hours was similar in both groups. No significant differences were observed in left ventricular morphology at the echocardiogram. CONCLUSION: These findings indicate that hyperreactive subjects have an exaggerated stress-induced cardiovascular response during the installation of the device.

Noninvasive ambulatory 24-hour blood pressure in patients with high normal blood pressure and exaggerated systolic pressure response to exercise.

Few studies have investigated the significance of abnormal increases in systolic pressure during exercise in patients with high normal blood pressure and its correlation with 24-hour ambulatory blood pressure monitoring and left ventricular structure. This study was performed in 30 sedentary subjects (42 +/- 4 years old) with high normal blood pressure. Fifteen subjects presenting < 220 mm Hg systolic pressure during ergometric exercise were compared with 15 others with systolic pressure > or = 220 mm Hg. Average 24-hour (systolic, 127 +/- 5 versus 142 +/- 4 mm Hg, P < .01; diastolic, 82 +/- 4 versus 92 +/- 3 mm Hg, P < .01), daytime (systolic, 130 +/- 6 versus 144 +/- 4 mm Hg, P < .01; diastolic, 84 +/- 4 versus 92 +/- 4 mm Hg, P < .01), and nighttime (systolic, 116 +/- 7 versus 132 +/- 6 mm Hg, P < .01; diastolic, 72 +/- 6 versus 85 +/- 6 mm Hg, P < .01) ambulatory blood pressure monitoring values were significantly higher in subjects with an exaggerated blood pressure response to exercise. No significant differences were observed in left ventricular morphology. These findings indicate that subjects presenting high normal blood pressure and exaggerated systolic pressure during exercise show significantly high ambulatory blood pressure monitoring values that are not associated with left ventricular hypertrophy.