Influence of multi-walled carbon nanotubes on the physico-chemical and biological responses of chitosan-based hybrid hydrogels.

Photoresponsive membranes were successfully obtained by combining chitosan (CS), poly(vinyl alcohol) (PVA) crosslinked with genipin (GEN) and filled with multi-walled carbon nanotubes (MWCNTs). It was demonstrated that adding a small quantity (0.01% w/v) of MWCNTs conferred to those nanocomposite hybrid hydrogels an outstanding photomechanical response under infrared irradiation. Moreover, it was observed that MWCNTs enhanced the crystallinity, increased the elastic modulus but did not contribute to the thermal stability of the nanocomposite hybrid hydrogels. The swelling capacity and contact angle values of these materials were modified through the addition of MWCNTs, and the offered free OH and NH2 functional groups in their current chemical structures. These functional groups - on hybrid hydrogels' surfaces - also enhanced the adhesion and proliferation of human dermal fibroblast cells, showing typical morphologies and sizes. Additionally, non-cytotoxic effects were observed for these nanocomposite hybrid hydrogels, suggesting their potential use in tissue engineering and biomedical applications. Chemical compounds studied in this article: Chitosan (PubChem CID: 71853); Polyvinyl alcohol (PubChem CID: 11199); Genipin (PubChem CID: 442424).

Anorectal malformations: definitive surgery during adulthood.

BACKGROUND: Anorectal malformations (ARMs) are rarely seen in adults, since majority of cases are corrected in infancy or childhood. The aim of this study was to describe the profile of patients who underwent definitive surgery to correct their ARM in adulthood, and to discuss the outcomes of surgery (morbidity, mortality, and function). METHODS: This retrospective study included patients 18 years old and above, managed surgically by the Division of Colorectal Surgery at the Philippine General Hospital, University of the Philippines, Manila, from January 1, 2004, to December 31, 2012. Data from the Integrated Surgical Information System and the patients' hospital records were used to fill out a Data Collection Form. Frequencies and percentages were then computed. RESULTS: Eight patients were included in the study. The most common reason for consult was recurrent urinary tract infection (UTI, 25%). One patient had an imperforate anus (IA) without a fistula, and 1 patient had IA with rectal atresia, and the 6 had an IA with a fistula. All but one (87.5%) of the patients had undergone a prior diversion in infancy or childhood. Definitive surgical procedures included posterior sagittal anorectoplasty (PSARP) in 3 patients, anal transposition in 2 patients, laparotomy with colocutaneous anastomosis in two patients, and laparotomy and PSARP in 1 patient. There were 3 cases (37.5%) of postoperative complications. These complications included ureteral injury, enterocutaneous fistula, anal stricture, rectal stricture, rectovesical fistula, and recurrent rectourethral fistula. There was no reported mortality. Five patients already had their stomas reversed at the time of this writing. CONCLUSION: Our results showed that the rarity of the disease, limited surgical experience, and a technically challenging anatomy make the management of ARMs that persist into adulthood a formidable undertaking.

A randomized controlled clinical trial comparing the outcomes of circumferential subcuticular wound approximation (CSWA) with conventional wound closure after stoma reversal.

BACKGROUND: The creation of a stoma is commonplace in colorectal surgery. Circumferential subcuticular wound approximation (CSWA) is a method of wound closure following stoma reversal that has been reported to result in decreased wound infection rates and more desirable aesthetic outcomes. The aim of the present study was to determine the effectiveness of the CSWA method, in terms of wound infection and cosmesis by comparing the technique to the conventional method of wound closure. METHODS: All adult patients who presented for stoma reversal at the outpatient clinic of the Division of Colorectal Surgery at the Philippine General Hospital were randomized into two groups, CSWA and conventional. Patients were followed up for up to 30 days postoperatively, photographic documentation of wound appearance was obtained, and wound infections and complications were documented. Patients were asked to complete a satisfaction survey at the end of the follow-up period. RESULTS: A total of 121 patients were included in the study. One (1.6%) patient in the CSWA group developed wound infection, while six (10%) patients in the conventional group had a wound infection (p = 0.061). The CSWA group had a higher total satisfaction score than the conventional group (25 and 24, respectively, p = 0.012). CONCLUSIONS: With regard to wound infection rates, the CSWA method was better than the conventional method, although this was found to be borderline significant. With regard to patient satisfaction, the CSWA method proved to be superior to the conventional method, and this was found to be statistically significant. In addition, the technique is applicable to all forms of stoma regardless of the bowel segment involved, trephine size, and indication for diversion.

Swine trichinellosis in slaughterhouses of the metropolitan area of Toluca.

In order to determine the prevalence of Trichinella spiralis infections in abattoirs of the metropolitan area of Toluca where pigs from commercial farms as well as backyard pigs are slaughtered, 539 swine diaphragm tissue samples were collected and examined by trichinoscopy and artificial digestion. Serum samples from the same animals were analyzed by ELISA using somatic and excretory/secretory antigens, and by Western blot analysis. T. spiralis muscle larvae were not found by trichinoscopy or artificial digestion. However, specific antibodies were detected by ELISA and confirmed by Western blotting in 12.4% of the serum samples examined. Analysis of risk factors showed no association of seropositive results with sex. However, significant higher risk was observed in swine seven to 12 months old and in backyard pigs, compared with pigs from commercial farms.

Ultrastructure and motility of the caudal epididymis spermatozoa from the volcano mouse (Neotomodon alstoni alstoni Merriam, 1898).

The volcano mouse Neotomodon alstoni alstoni is a genus endemic to the higher elevations of the Mexican transvolcanic belt. In the present study we examined for the first time the morphological features of the spermatozoa taken from the caudal epididymis of this species by transmission and scanning electron microscopy. Spermatozoan motility was studied in sucrose and bicarbonate solutions; vitality and morphology were observed by light microscopy. Transmission electron microscopy shows that the head of spermatozoon is asymmetric and possesses a large and curved hook. The axoneme of the spermatozoan tail is highly developed at fibers 1, 5, and 6. Absolute and relative measurements of the length of the head, the midpiece, and the rest of the tail were also obtained. N. alstoni alstoni spermatozoa were hyperactive in the presence of 290 mM sucrose and 10 and 20 nM bicarbonate solutions exhibited high motility (180-190 microm/sec), and high flagellum beating frequency (10-12 Hz). In contrast, the spermatozoa in 310 mM sucrose solution showed scarce motility (13.5 +/- 3.8 microm/sec) and low beating frequency (1.5 +/- 0.4 Hz). It is proposed that the volcano mouse spermatozoa possess some features very similar to other mammalian spermatozoa and that bicarbonate triggers caudal epididymal sperm motility of this species. J. Exp. Zool. 287:316-326, 2000.

The P450 aromatase (P450 arom) gene is asymmetrically expressed in a critical period for gonadal sexual differentiation in the chick.

Steroid hormones appear to play an important role in gonadal sex differentiation of birds. Here we studied the steady-state level of the P450 arom mRNA by reverse transcriptase polymerase chain reaction (RT-PCR) in the left and the right presumptive ovary and testis of developing chicken embryos. The gonads were evaluated every hour during the undifferentiated period, at 144-156 h of incubation (h/i), and every 24 h after sexual differentiation at 168 and 192 h/i. Activity of P450 arom was determined by estrone production from [3H]androstenedione at 144-192 h/i. Moreover, morphological development of the gonad was also examined by light microscopy. Results show that onset of P450 arom mRNA and its protein activity were simultaneously detected in the left and the right ovaries at 147 h/i. Asymmetric function of P450 arom gene expression was observed at 156 h/i when morphological gonadal differentiation is first recognized. Biotransformation of [3H]androstenedione to estrone was also asymmetrically detected between the left and right gonad at 156 h/i and asymmetry was maintained throughout the analyzed stages. It is proposed that there is a gene in birds that is asymmetrically expressed in the undifferentiated stage of the female and the male gonad. In the female this gene could promote P450 arom gene expression, increasing estrogen production, which in turn could induce ovarian cortex proliferation and expression of other structural estrogen-regulated genes involved in ovarian sexual determination.

Delayed expression of the insulin-like growth factor I (IGF-I) gene in the XY sex-reversed female mouse ovary.

When the Y chromosome of Mus musculus domesticus (YDOM) mouse strain from Tirano (Italy) or Mus musculus poschiavinus (YPOS) from Poschiavo (Switzerland), is placed onto the C57BL/6J (B6) inbred background, the YDOM chromosome fails to induce normal testicular differentiation and instead allows development of ovaries and ovotestes in embryonic life. During postnatal development some hermaphroditic males become fertile whereas the XY females lack normal estrus cyclicity, produce low levels of gonadal steroids and cannot carry pregnancy to term. Here we studied the transcription of the IGF-I gene known to be involved in steroidogenesis. RNA was isolated from the XX and the XY ovaries at 1 to 40 d.p.p. and subjected to RT-PCR analysis. Immunocytochemical staining for IGF-I was performed to identify the cell type of IGF-I peptide localization, and protein expression was examined by Western blot analysis. The present results indicate that the IGF-I transcript was expressed at 1 d.p.p. in the XX ovary throughout the studied stages whereas in the XY ovary mRNA IGF-I was not detected until 15 d.p.p. IGF-I protein was identified in theca cells in the whole XX control ovary, while in the XY ovary, strong staining for IGF-I was found in the theca cells of the cortex. Faint staining was also seen around the medullary sterile cords. Western blot analysis showed normal onset in the XX and the XY ovary, but a different staining pattern for IGF-I in the XY ovary at 11 and 26 d.p.p. compared to the XX control ovary. We propose that delayed expression of IGF-I in the XY mouse ovary may be responsible for low steroid production and fertility problems in the XY sex-reversed adult female mouse.