Biotin deficiency and biotin excess: Effects on the female reproductive system

Biotin deficiency and biotin excess have both been found to affect reproduction and cause teratogenic effects. In the reproductive tract, however, the effects of biotin have not been well established yet. We investigated the effects of varying biotin content diets on the oestrus cycle, ovarian morphology, estradiol and progesterone serum levels, and the uterine mRNA abundance of their nuclear receptors, as well as on the activity of the estradiol-degrading group of enzymes cytochrome P450 (CYP) in the liver. Three-week-old female BALB/cAnN Hsd mice were fed a biotin-deficient, a biotin-control, or a biotin-supplemented diet (0, 7.2 or 400 μmol of free biotin/kg diet, respectively) over a period of nine weeks. Striking effects were observed in the biotin-deficient group: mice showed arrested estrous cycle on the day of diestrus and changes in ovary morphology. Estradiol serum concentration increased 49.2% in biotin-deficient mice compared to the control group, while the enzymatic activities of CYP1A2 and CYP2B2 increased (P < 0.05). The mRNA abundance of nuclear estrogen and progesterone receptors decreased in the biotin-deficient mice. In the biotin-supplemented group we found that, in spite of a significant (P < 0.05) decrease in the number of primary and Graafian follicles and in CYP1A2 activities, mice exhibited 105.4% higher serum estradiol concentration than the control group. No changes in the expression of the nuclear receptors were observed. No significant differences were observed in serum progesterone among the groups. Our results indicate that both the deficiency and the excess of biotin have significant effects on the female mouse reproductive system.     

Opposing roles for superoxide and nitric oxide in the NaCl stress-induced upregulation of antioxidant enzyme activity in cotton callus tissue

The roles of superoxide and NO in the NaCl-induced upregulation on antioxidant enzyme activity were investigated in NaCl-tolerant cotton calli. Both NaCl and paraquat treatments resulted in significant increases in superoxide production. The activities of ascorbate peroxidase (APX), catalase, glutathione reductase (GR), and peroxidase also increased significantly within 2 h after applying the stress. Pre-treatment with the superoxide scavenger, N-acetyl l-cysteine (NAC), completely removed the superoxide and inhibited the upregulation of antioxidant enzyme activity in the tissue treated with either NaCl or paraquat. NaCl stress also resulted in a significant increase in the NO level. Experiments were also carried out to measure antioxidant enzyme activity in cotton calli exposed to NO, the NO producer sodium nitroprusside (SNP), and the NO scavenger 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide (PTIO) under different salt stress conditions. The direct addition of NO gas produced no change in the activities of catalase and GR and caused a significant decrease in APX activity when compared to the controls. When the calli was treated with SNP in the absence of NaCl stress, APX and GR activities decreased significantly and catalase activity was only slightly higher than the control. Treatment with SNP in the presence of NaCl stress resulted in a significant decrease in APX activity, and GR and APX activities were not significantly different from those observed in the NaCl treatment alone. In the presence of PTIO, the activities of all three enzymes increased in the presence or absence of NaCl stress. These results suggest that reactive oxygen species (ROS) such as superoxide radicals may serve as signal transduction molecules to switch “on” the early NaCl-induced up-regulation of antioxidant enzyme activity, while NO may play a role in switching “off” the response after other mechanisms in the cascade of events responsible for NaCl tolerance have been activated.     

Sleep-dependent changes in the coupling between heart period and blood pressure in human subjects

We investigated whether in human subjects, the pattern of coupling between the spontaneous fluctuations of heart period (HP) and those of systolic blood pressure (SBP) differs among wake-sleep states. Polysomnographic recordings and finger blood pressure measurements were performed for 48 h in 15 nonobese adults without sleep-disordered breathing. The cross-correlation function (CCF) between the fluctuations of HP and SBP at frequencies <0.15 Hz was computed during quiet wakefulness (QW), light (stages 1 and 2) and deep (stages 3 and 4) nonrapid-eye-movement sleep (NREMS), and rapid-eye-movement sleep (REMS). A positive correlation between HP and the previous SBP values, which is the expected result of baroreflex feedback control, was observed in the sleep states but not in QW. In deep NREMS, the maximum CCF value was significantly higher than in any other state, suggesting the greatest baroreflex contribution to the coupling between HP and SBP. A negative correlation between HP and the subsequent SBP values was also observed in each state, consistent with the mechanical feed-forward action of HP on SBP and with central autonomic commands. The contribution of these mechanisms to the coupling between HP and SBP, estimated from the minimum CCF value, was significantly lower in deep NREMS than either in light NREMS or QW. These results indicate that the pattern of coupling between HP and SBP at low frequencies differs among wake-sleep states in human subjects, with deep NREMS entailing the highest feedback contribution of the baroreflex and a low effectiveness of feed-forward mechanisms.     

From the "charretera" to the supraclavicular fascial island flap: revisitation and further evolution of a controversial flap

Wide tissue defects located on the face and neck area often require distant flaps or free flaps to achieve a tension-free reconstruction together with an acceptable aesthetic result. The supraclavicular island flap surely represents a versatile and useful flap that can be used in case of large tissue losses. Because of its wide arc of rotation, which ensures a 180-degree mobilization anteriorly and posteriorly, the flap can reach distant sites when harvested as a pure island flap. The main vascular supply of the flap, the supraclavicular artery, a branch of the transverse cervical artery or, less frequently, of the suprascapular artery, though reliable, is not a very large vessel. In some particular cases, when too much tension or angles that are too tight are present, the vascular supply of the flap can be difficult and special care must be taken to avoid flap failure. To avoid this problem, the authors started harvesting the flap not as a pure island flap but with a fascial pedicle, thin and resistant, which ensures good reliability; also, when a higher tension rate is present, it avoids the risk of excessive traction or kinking of the vessels. Twenty-five consecutive patients with various defects located on the head, neck, and thorax area were treated in the past 2 years using the modified supraclavicular island flap. There was no flap loss or distant necrosis of the flap, and there was marginal skin deepithelialization in only two cases, which only required minor surgery. Postoperative morbidity was low, similar to the classic supraclavicular island flap, with primarily closed donor sites, except for one case, and tension-free scars. The authors show how the modified supraclavicular island flap is a reliable and safe flap that gives a good aesthetic result with low risk concerning the viability of the transferred skin. The technique, similar to supraclavicular island flap harvesting, is easy to perform and is attractive in patients at risk for poor or delayed healing such as smokers or patients with complex medical histories.     

The Sensitizers Nickel Sulfate and 2,4-dinitrofluorobenzene Increase CD40 and IL-12 Receptor Expression in a Fetal Skin Dendritic Cell Line

Dendritic cells (DCs) are antigen-presenting cells (APCs) capable of capturing haptens and to process and present them to T lymphocytes. In order to sensitize T cells for contact hypersensitivity (CHS), skin DCs suffer a maturation process with modifications on their surface molecules. The aim of this work was to evaluate changes induced by two contact sensitizers, 2,4-dinitrofluorobenzene (DNFB) and nickel sulfate (NiSO₄), and a non-sensitizer 2,4-dichloronitrobenzene (DCNB), on the protein levels of two activation markers, CD40 and IL-12 receptor (IL-12R), in a mouse skin dendritic cell line (FSDC). The expression of CD40 and IL-12R proteins was evaluated by western blot assay and direct immunofluorescence microscopy. The results showed that CD40 and IL-12R expression increased significantly after cell exposure to NiSO₄ and DNFB, although DNFB exhibited a stronger activity. There was no effect with DCNB. The epidermal cytokine granulocyte–macrophage colony-stimulating factor (GM-CSF), also used in the experiments, slightly increased the expression of both CD40 and IL-12R and when tested together with the sensitizers the effect was partially additive. The results suggest that the sensitizers DNFB and NiSO₄ are directly involved on the changes of the surface markers CD40 and IL-12R in skin DCs, during the sensitization phase of CHS, and this effect may be enhanced by GM-CSF. In contrast, no effect was observed with DCNB.     

Identification of human papilloma viruses in male dysplastic genital lesions

The association of Human Papillomaviruses (HPV) DNA with female genital lesions has been widely documented whereas little has been reported about male genital pathologies. The aim of this work was to investigate the presence of HPV DNA and the genotype involved in male dysplastic genital lesions. All samples were analysed by polymerase chain reaction (PCR) to amplify HPV E1 and L1 genes. The PCR products were subjected to restriction fragment length polymorphism (RFLP) to determine the HPV genotype. We analysed 209 male genital biopsies from different lesions: mostly from acuminate condylomata and from Buschke-Lowenstein tumours, Bowen papulosis, leukoplakia of the glans, scrotal lymphangioma, penile horn and penile/perianal verrucous carcinoma. Our results revealed the constant presence of viral DNA in genital condylomata, mainly associated with low risk HPV; the presence of the same genotypes was also detected in some of the examined rare pathologies.     

Estrogen Receptor-α Correlates with Higher Fungal Cell Number in Oral Paracoccidioidomycosis in Women

Background

Paracoccidioidomycosis is a neglected tropical fungal infection with great predilection for adult men, indicating the participation of female hormone estrogen in preventing paracoccidioidomycosis development in women. Estrogen has an immunologic effect leading to polarization toward the Th2 immune response, which favors the disease evolution.

Objectives

To evaluate estrogen and progesterone receptors in oral paracoccidioidomycosis lesions and to verify any association with tissue fungi counting in women and men.

Methods

Thirty-two cases of chronic oral paracoccidioidomycosis were included. Immunohistochemical analyses for anti-estrogen receptor-α, anti-progesterone receptor and anti-Paracoccidioides brasiliensis antibodies were performed. The differences between women and men and the relations among the immunomarkers for each gender were also evaluated.

Results

A significant positive correlation was observed between estrogen receptor-α and the amount of fungi in women. In addition, estrogen receptor-α was mildly expressed in the inflammatory cells of female patients, while progesterone receptor was expressed in both genders, with similar expression between women and men. Moreover, fungi counting revealed no differences between genders.

Conclusions

Estrogen receptor-α was expressed only in women and showed a positive correlation with the amount of fungi in oral paracoccidioidomycosis, while progesterone receptor was observed in both genders and exhibited no correlation with estrogen receptor-α or fungi counting.

     

Feeding strategy of silverside species in eutrophic Lake Pátzcuaro,Mexico

The trophic guild, niche breadth, and trophic position of two different ontogenetic phases were measured according to the size of Chirostoma spp. captured in different zones of Lake Pátzcuaro, Mexico. Analyses were carried out at the genus level due the difficulties to find diagnostic characters to separate the three small silverside species accurately, since even the molecular analyses of mitochondrial DNA for a subsample of the most morphologically differentiated specimens were conducted without success. Fish were captured with a seine net during the wet (September and November 2009) and dry (February and June 2010) seasons at four environmentally different sites. Gut contents of 480 Chirostoma specimens were divided into size‐class intervals of 38–51 mm and 66–71 mm for analyses. The contribution of each food item was quantified using the frequency of occurrence and area percentage. Fish were categorized by size, and diets were compared between fish sizes and sites. Dorsal muscle tissue and zooplankton were obtained for nitrogen isotope signature (δ¹⁵N) analyses. The trophic guild was determined using a modified quadrant method for gut content analysis; the importance of each prey item was estimated according to a modified index of relative importance. Niche breadth was calculated by the Levins’ Index. The trophic position was assessed using the TrophLab Program and stable isotope analysis. The index of relative importance among study sites and fish size classes was determined by a multivariate approach. Silversides represent a secondary and tertiary consumer in Lake Pátzcuaro that feed mainly on evasive prey, such as copepods (55%) and on non‐evasive prey, such as cladocerans (25%) at sites with the lowest transparency in the water column (from 350 mm to 150 mm). Fish scales (11%) and insects (6%) were secondary food items. Ingestion of juvenile silversides was rare (1%). Chirostoma spp. prey on insects on the lake bottom and on water hyacinth roots. Based on δ¹⁵N analysis, the trophic position of silversides changes between wet and dry seasons. Their opportunistic and specialized predatory feeding strategy indicates the capability of silversides to resist anthropic changes in the lake.