Skin biological responses to urban pollution in an ex vivo model.

The skin epidermis is continuously exposed to external aggressions, including environmental pollution. The cosmetic industry must be able to offer dedicated products to fight the effects of pollutants on the skin. We set up an experimental model that exposed skin explants maintained in culture to a pollutant mixture. This mixture P representing urban pollution was designed on the basis of the French organization 'Air Parif' database. A chamber, called Pollubox®, was built to allow a controlled nebulization of P on the cultured human skin explants. We investigated ultrastructural morphology by transmission electron microscopy of high pressure frozen skin explants. A global transcriptomic analysis indicated that the pollutant mixture was able to induce relevant xenobiotic and antioxidant responses. Modulated detoxifying genes were further investigated by laser micro-dissection coupled to qPCR, and immunochemistry. Both approaches showed that P exposure correlated with overexpression of detoxifying genes and provoked skin physiological alterations down to the stratum basale. The model developed herein might be an efficient tool to study the effects of pollutants on skin as well as a powerful testing method to evaluate the efficacy of cosmetic products against pollution.

Vitamin C-squalene bioconjugate promotes epidermal thickening and collagen production in human skin.

Vitamin C (Vit C) benefits to human skin physiology notably by stimulating the biosynthesis of collagen. The main cutaneous collagens are types I and III, which are less synthesized with aging. Vit C is one of the main promotors of collagen formation but it poorly bypasses the epidermis stratum corneum barrier. To address this challenge, we developed a lipophilic version of Vit C for improving skin diffusion and delivery. Vit C was covalently conjugated to squalene (SQ), a natural lipid of the skin, forming a novel Vit C-SQ derivative suitable for cream formulation. Its biological activity was investigated on human whole skin explants in an ex vivo model, through histology and protein and gene expression analyses. Results were compared to Vit C coupled to the reference lipophilic compound palmitic acid, (Vit C-Palmitate). It was observed that Vit C-SQ significantly increased epidermal thickness and preferentially favored collagen III production in human skin after application for 10 days. It also promoted glycosaminoglycans production in a higher extent comparatively to Vit C-Palmitate and free Vit C. Microdissection of the explants to separate dermis and epidermis allowed to measure higher transcriptional effects either in epidermis or in dermis. Among the formulations studied, the strongest effects were observed with Vit C-SQ.

Reverse engineering techniques applied to a human skull, for CAD 3D reconstruction and physical replication by rapid prototyping.

The production of a copy of an existing object of complex shape is one of the typical applications of the integration between two modern computer-based technologies, reverse engineering (RE) and rapid prototyping (RP). The method is extremely versatile and can be used in various applicative domains (e.g. replacement of anatomical parts with artificial prostheses, replication of skeletal remains). Two different acquisition techniques of images of a skull, by laser and by CT scan, were compared to ascertain which enabled more accurate reproduction of the original specimen. The skull was chosen due to it being the body part most often used in medico-legal investigations (for personal identification, skull-photo superimposition techniques, forensic art, etc). Comparison between the copy and the original yielded satisfactory results for both techniques. However, CT scanning demonstrated some advantages over the laser technique, as it provided a cleaner point cloud, enabling shorter pre-reproduction processing times, as well as data on the internal parts, which resulted in the reproduction of a more faithful copy.

Oxidative stress during myocardial ischaemia and heart failure.

Oxidative stress is a condition in which oxidant metabolites exert their toxic effect because of an increased production or an altered cellular mechanism of protection. The heart needs oxygen avidly and, although it has powerful defence mechanisms, it is susceptible to oxidative stress, which occurs, for instance, during post-ischaemic reperfusion. Ischaemia causes alterations in the defence mechanisms against oxygen free radicals, mainly a reduction in the activity of mitochondrial superoxide dismutase and a depauperation of tissue content of reduced glutathione. At the same time, production of oxygen free radicals increases in the mitochondria and leukocytes and toxic oxygen metabolite production is exacerbated by re-admission of oxygen during reperfusion. Oxidative stress, in turn, causes oxidation of thiol groups and lipid peroxidation leading first to reversible damage, and eventually to necrosis. In man, there is evidence of oxidative stress (determined by release of oxidised glutathione in the coronary sinus) during surgical reperfusion of the whole heart, or after thrombolysis, and it is related to transient left ventricular dysfunction or stunning. Data on oxidative stress in the failing heart are scant. It is not clear whether the defence mechanisms of the myocyte are altered or whether the production of oxygen free radicals is increased, or both. Recent data have shown a close link between oxidative stress and apoptosis. Relevant to heart failure is the finding that tumour necrosis factor, which is found increased in failing patients, induces a rapid rise in intracellular reactive oxygen intermediates and apoptosis. This series of events is not confined to the myocytes, but occurs also at the level of endothelium, where tumour necrosis factor causes expression of inducible nitric oxide synthase, production of the reactive radical nitric oxide, oxidative stress and apoptosis. It is therefore, possible that the immunological response to heart failure results in endothelial and myocyte dysfunction through oxidative stress mediated apoptosis. Clarification of these mechanisms may lead to novel therapeutic strategies.

PCR detection of specific Leishmania-DNA in patients with periodontal disease.

This study deals with the detection of Leishmania braziliensis DNA in gingival specimens from 10 individuals who all had suffered from cutaneous leishmaniasis 5-10 years prior to the examination and all had been treated with anti-leishmaniasis drugs. This preliminary study gives an interesting contribution to the oral microbiology of this disease, with the observation that inflamed periodontal tissues can serve as a factor affecting the dispersion of Leishmania parasites in individuals who had suffered from cutaneous leishmaniasis. These finding are corroborated by the results of polymerase chain reaction (PCR) which demonstrated the presence of Leishmania DNA in tissue samples of patients with periodontal diseases.

High risk human papillomavirus in oral squamous carcinoma: evidence of risk factors in a Venezuelan rural population. Preliminary report.

In a search for the presence of human papillomavirus (HPV) and some etiologic cofactors in oral squamous cell carcinoma (OSCC), 50 women diagnosed as OSCC were analyzed by a multiplex polymerase chain reaction (PCR) assay specific for HPV types 6, 11, 16, and 18. This study revealed that 60% (30/50) of the OSCC patients were positive for HPV-DNA sequences. This group was analyzed according to smoking, alcohol consumption, number of pregnancies, poor oral health and low social economic status. The current results indicate an increased incidence of HPV malignant types in the oral cavity in women with OSCC. Also, they support a multifactorial model of oral cancer causation.

Myocardial parasite persistence in chronic chagasic patients.

The persistence of Trypanosoma cruzi tissue forms was detected in the myocardium of seropositive individuals clinically diagnosed as chronic chagasic patients following endomyocardial biopsies (EMBs) processed by immunohistochemical (peroxidase-anti-peroxidase [PAP] staining) and molecular (polymerase chain reaction [PCR]) techniques. An indirect immunofluorescent technique revealed antigenic deposits in the cardiac tissue in 24 (88.9%) of 27 patients. Persistent T. cruzi amastigotes were detected by PAP staining in the myocardium of 22 (84.6%) of 26 patients. This finding was confirmed with a PCR assay specific for T. cruzi in 21 (91.3%) of 23 biopsy specimens from the same patients. Statistical analysis revealed substantial agreement between PCR and PAP techniques (k = 0.68) and the PCR and any serologic test (k = 0.77). The histopathologic study of EMB specimens from these patients revealed necrosis, inflammatory infiltrates, and fibrosis, and made it possible to detect heart abnormalities not detected by electrocardiogram and/or cineventriculogram. These indications of myocarditis were supported by the detection of T. cruzi amastigotes by the PAP technique or its genome by PCR. They suggest that although the number of parasites is low in patients with chronic Chagas' disease, their potential for heart damage may be comparable with those present during the acute phase. The urgent necessity for testing new drugs with long-term effects on T. cruzi is discussed in the context of the present results.

Correlation between HPV types associated with oral squamous cell carcinoma and cervicovaginal cytology: An in situ hybridization study.

Epidemiologic and clinical evidence suggests a possible relationship between the human papillomavirus types found in oral squamous cell carcinoma and cervicovaginal cancer. To try to address this question, we analyzed by in situ hybridization 50 paraffin-embedded biopsies of oral squamous cell carcinomas and their corresponding Papanicolaou smears using nonradioactive DNA probes for human papillomavirus type 6/11 and 16/18. This analysis revealed that 70% (35 of 50) of oral squamous cell carcinomas and 56% (28 of 50) of Papanicolaou smears were positive for one or both of these human papillomavirus DNA probes. In 23 of the 28 patients who were positive for human papillomavirus sequences in the cervicovaginal tract, we found the same human papillomavirus type in the oral cavity. Five of the positive in situ hybridization Papanicolaou smears were associated with negative in situ hybridization oral squamous cell carcinomas. Our data suggest that after a primary infection by human papillomavirus, other mucosal sites may eventually become infected. Local environmental factors may contribute to the pathogenesis of lesions such as oral squamous cell carcinoma.

a 49-year-old woman with dyspnoea, palpitations and syncope.

Pulmonary hypertension is rarely described in association with Sjögren's syndrome. The authors report the case of a patient in which pulmonary hypertension was the inaugural clinical manifestation of primary Sjögren's syndrome. Clinical assessment, differential diagnosis, etiopathological implications, and therapeutic approach are discussed.

Long-term reliability of single lead atrial synchronous pacing systems using closely spaced atrial dipoles: five-year experience.

To assess the long-term capability of single atrioventricular (AV) lead VDD pacing systems using close atrial dipoles to assure reliable atrial guided pacing, the safety and efficacy of 86 VDD units implanted in 73 patients at a single center since November 1988 was reviewed. All patients suffered from advanced AV block with normal sinoatrial function. Sixty five patients received a LEM/CCS Twinal 30/30S system, four patients received a Vitatron-Saphir system, and four patients received a Medtronic Thera VDR 8348 system. All patients underwent provocative tests in search of myopotential interference, and Holter recordings; in a group of patients who underwent pacemaker replacement a comparison was made between implant and replacement measurements. The mean follow-up duration was 27.3 months. A high percentage of successfully VDD paced patients and a low incidence of pacemaker malfunction, regularly solved by pacemaker reprogramming, was reported. Atrial signal amplitudes comparable to those measured at implant were found at replacement in all patients. These data support the long-term reliability of single AV lead VDD pacing systems with closely spaced atrial dipoles, as well as stable atrial sensing by floating bipolar atrial electrodes and effective atrial synchronous ventricular pacing over time.

AV delay optimization and management of DDD paced patients with dilated cardiomyopathy.

Ten DDD paced patients, suffering from dilated cardiomyopathy in the NYHA functional classes III or IV were studied by means of Doppler echocardiography at different programmed values of atrioventricular (AV) delay (200, 150, 120, 100, and 80 msec). The following variables were evaluated: LV diameter, ejection fraction, mitral and aortic flow velocity integrals, and stroke volume. During VDD pacing, a resting AV delay associated with the best diastolic filling and systolic function was identified and programmed individually. Shortening of the AV delay to about 100 msec was associated with a gradual and progressive improvement. Further decrease caused an impairment of systolic function. The patients were clinically and hemodynamically reevaluated after 2 months of follow-up. A reduction of NYHA class and an improvement of LV function were consistently found. The reported data suggest that programming of an optimal AV delay may improve myocardial function in DDD paced patients with congestive heart failure. This result may be the consequence of an optimization of left ventricular filling and a better use of the Frank-Starling law.

Focal epithelial hyperplasia: human-papillomavirus-induced disease with a genetic predisposition in a Venezuelan family.

A study on the presence of human papillomavirus (HPV) DNA sequences and focal epithelial hyperplasia (FEH) in a family of Venezuelan ancestry has revealed that FEH is an HPV-induced disease presenting familial aggregation. The genealogical evidence indicates a genetic predisposition to the disease.

Detection of human papillomavirus-related oral verruca vulgaris among Venezuelans.

A sensitive in situ hybridization test under low stringency conditions (LCS) with a set of digoxigenin-labeled human papillomavirus mixed probes (D-L HPV MP) revealed a positive reaction in 8 of 10 cases of oral verruca vulgaris (OVV). Ages ranged from 5 to 37 years with a mean of 14.5 years. 50% of all cases were located intraorally on the hard palate, followed in frequency by the commissures. These preliminary findings provide evidence of the role of HPV in OVV from a sample of the Venezuelan population. We show that in situ hybridization conducted under LSC is useful in HPV detection (regardless of the type) and the digoxigenin-labeling system is a rapid, relatively easy and specific method. In addition, this technique permits the retrospective evaluation of routinely processed material, thus widening the investigative spectrum for HPV.

Italian multicenter study on a single lead VDD pacing system using a narrow atrial dipole spacing.

Since November 1988, 514 patients with advanced atrioventricular (AV) block and normal sinoatrial function have received the single lead VDD pacing system Twinal 30 Lem/CCS in 30 Italian centers. At implantation, particular attention was paid to the correct positioning of the atrial dipole in the mid- to mid-high right atrium and to the atrial electrogram characteristics. The follow-up included a chest X ray, to be performed before discharge of the patient from the hospital, telemetric evaluations of the endoatrial potential, provocative tests for interferences by myopotentials, 24-hour ambulatory EGG recordings, and where possible, exercise stress tests. The mean follow-up duration was 15.2 months, ranging from 1 to 42 months. A very low percentage of chronic atrial fibrillation, loss of atrial sensing, and system replacement was reported, most of the patients (93.5%) being paced in VDD mode. All investigations indicated an excellent overall system performance, stable AV synchrony, and infrequent myopotential interference, and a low complication rate throughout the follow-up period.

Human papillomavirus in oral verrucal-papillary lesions. A comparative histological, clinical and immunohistochemical study.

The purpose of this study was to determine the presence of Human Papillomavirus (HPV) virions in the verrucal-papillary (OVP) lesions by clinical, histological and immunohistochemical [peroxidase-antiperoxidase (PAP) features]. Thirty seven positive cases were compared with 47 negative cases. Considerable overlapping of clinical and histological features can be seen among all these lesions. The study provides evidence that there are no clinical or histologic features with taken alone are strongly correlated with the presence of virions in oral lesions.

In situ hybridization with digoxigenin-labelled DNA probes for the detection of human papillomavirus-induced focal epithelial hyperplasia among Venezuelans.

An in situ hybridization assay with digoxigenin-labelled probes was used to detect the presence of human papillomavirus (HPV) sequences in ten related Venezuelan patients with the diagnosis of focal epithelial hyperplasia. The samples displayed HPV sequences in all cases. Further restriction analysis in four of the patients suggested the presence of HPV-13 in oral lesions.

Role of sinus node artery disease in sick sinus syndrome in inferior wall acute myocardial infarction.

This study was undertaken to evaluate a possible role of sinus node (SN) artery disease in the pathogenesis of sick sinus syndrome (SSS) in patients with an inferior wall acute myocardial infarction (AMI). Coronary angiography and electrophysiologic studies of the SN, both in the basal state and after pharmacologic autonomic blockade, were performed in 23 study patients (mean age 60 years) with SSS and a previous inferior wall AMI and in another 23 control patients (mean age 57 years) with normal sinus rate and a previous inferior AMI. Stenosis of the SN artery (or that proximal to its origin) greater than 50% was present in 13 study patients (56%) and in 8 control patients (34%) (p less than 0.05). In the study group, the intrinsic heart rate was abnormal in 5 of the 6 patients (83%) with severe SN artery stenosis (greater than or equal to 75% narrowing), in 3 of the 7 (43%) with moderate stenosis (50 to 75% narrowing) and in 3 of the 10 (30%) with insignificant stenosis (less than 50% narrowing). In the study group, the correlation between the SN measures (heart rate, corrected SN recovery time and sinoatrial conduction time) and the severity of SN artery stenosis was good after autonomic blockade (r between 0.59 and 0.64) and poor in the basal state. These data provide evidence for a role of SN artery disease in the pathogenesis of SSS in patients with an inferior wall AMI.