Biomimetic Adhesive Micropatterned Hydrogel Patches for Drug Release

The optimized physical adhesion between bees' leg hairs and pollen grains-whereby the latter's diameter aligns with the spacing between the hairs-has previously inspired the development of a biomimetic drug dressing. Combining this optimized process with the improved natural mussels' adhesion in wet environments in a dual biomimetic process, it is herein proposed the fabrication of a natural-derived micropatterned hydrogel patch of methacrylated laminarin (LAM-MET), with enriched drug content and improved adhesiveness, suitable for applications like wound healing. Enhanced adhesion is accomplished by modifying LAM-MET with hydroxypyridinone groups, following the patch microfabrication by soft lithography and UV/vis-irradiation, resulting in a membrane with micropillars with a high aspect ratio. Following the biomimetics rational, a drug patch is engineered by combining the microfabricated dressing with drug particles milled to fit the spaces between pillars. Controlled drug release is achieved, together with inherent antibacterial activity against Escherichia coli and Pseudomonas aeruginosa, and enhanced biocompatibility using the bare micropatterned patches. This new class of biomimetic dressings overcomes the challenges of current patches, like poor mechanical properties and biocompatibility, limited adhesiveness and drug dosage, and lack of prolonged antimicrobial activity, opening new insights for the development of high drug-loaded dressings with improved patient compliance.

Multi-layer pre-vascularized magnetic cell sheets for bone regeneration

The lack of effective strategies to produce vascularized 3D bone transplants in vitro, hampers the development of thick-constructed bone, limiting the translational of lab-based engineered system to clinical practices. Cell sheet (CS) engineering techniques provide an excellent microenvironment for vascularization since the technique can maintain the intact cell matrix, crucial for angiogenesis. In an attempt to develop hierarchical vascularized 3D cellular constructs, we herein propose the construction of stratified magnetic responsive heterotypic CSs by making use of iron oxide nanoparticles previously internalized within cells. Magnetic force-based CS engineering allows for the construction of thick cellular multilayers. Results show that osteogenesis is achieved due to a synergic effect of human umbilical vein endothelial cells (HUVECs) and adipose-derived stromal cells (ASCs), even in the absence of osteogenic differentiating factors. Increased ALP activity, matrix mineralization, osteopontin and osteocalcin detection were achieved over a period of 21 days for the heterotypic CS conformation (ASCs/HUVECs/ASCs), over the homotypic one (ASCs/ASCs), corroborating our findings. Moreover, the validated crosstalk between BMP-2 and VEGF releases triggers not only the recruitment of blood vessels, as demonstrated in an in vivo CAM assay, as well as the osteogenesis of the 3D cell construct. The in vivo angiogenic profile also demonstrated preserved human vascular structures and human cells showed the ability to migrate and integrate within the chick vasculature.

Applicability of in vitro bioassays for the diagnosis of ivermectin resistance in Rhipicephalus microplus (Acari: Ixodidae)

The applicability of laboratory bioassays to diagnose ivermectin (IVM) resistance in Rhipicephalus microplus was evaluated. Adult immersion tests (AITs), larval immersion tests (LITs) and larval packet tests (LPTs) were performed to characterise the effects of ivermectin toxicity on adults and larvae of a susceptible reference strain. The AIT was determined to be a reasonable assay but requires a large number of individuals to attain interpretable results. The LIT and LPT were validated with an IVM resistant strain, revealing resistance ratios (RRs) of 6.73 and 1.49, respectively. In a field survey, nine different populations of cattle tick from the states of São Paulo and Mato Grosso do Sul, Brazil, were analysed with the LIT. Populations without previous exposure to ivermectin exhibited RRs between 0.87 and 1.01. Populations previously exposed to IVM showed RRs between 1.83 and 4.62. The LIT was more effective at discriminating between resistant and susceptible populations than the LPT. The use of the LIT is recommended for the diagnosis of ivermectin resistance in R. microplus.

Estradiol and testosterone concentrations in follicular fluid as criteria to discriminate between mature and immature oocytes

The objective of the present study was to examine the association between follicular fluid (FF) steroid concentration and oocyte maturity and fertilization rates. Seventeen infertile patients were submitted to ovulation induction with urinary human follicle-stimulating hormone, human menopausal gonadotropin and human chorionic gonadotropin (hCG). A total of 107 follicles were aspirated after hCG administration, the oocytes were analyzed for maturity and 81 of them were incubated and inseminated in vitro. Progesterone, estradiol (E2), estrone, androstenedione, and testosterone were measured in the FF. E2 and testosterone levels were significantly higher in FF containing immature oocytes (median = 618.2 and 16 ng/ml, respectively) than in FF containing mature oocytes (median = 368 and 5.7 ng/ml, respectively; P < 0.05). Progesterone, androstenedione and estrone levels were not significantly different between mature and immature oocytes. The application of the receiver-operating characteristic curve statistical approach to determine the best cut-off point for the discrimination between mature and immature oocytes indicated levels of 505.8 ng/ml for E2 (81.0% sensitivity and 81.8% specificity) and of 10.4 ng/ml for testosterone (90.9% sensitivity and 82.4% specificity). Follicular diameter was associated negatively with E2 and testosterone levels in FF. There was a significant increase in progesterone/testosterone, progesterone/E2 and E2/testosterone ratios in FF containing mature oocytes, suggesting a reduction in conversion of C21 to C19, but not in aromatase activity. The overall fertility rate was 61% but there was no correlation between the steroid levels or their ratios and the fertilization rates. E2 and testosterone levels in FF may be used as a predictive parameter of oocyte maturity, but not for the in vitro fertilization rate.

Doppler study of the uterine arteries and ovarian stroma in patients with polycystic ovary syndrome

Doppler analysis of the uterine arteries and ovarian stroma was performed by transvaginal ultrasound in 24 patients with polycystic ovary syndrome (PCOS) and 22 ovulatory women. Vascularization of the ovarian stroma was more abundant in patients with PCOS than in control women, but no significant difference in the mean pulsatility index (PI) was observed between groups (1.14 +/- 0.28 for the PCOS group and 1.05 +/- 0.19 for the control group). The mean PI of the uterine arteries was significantly higher in the PCOS group (PI = 3.7 +/- 0.8) than in the control group (PI = 2.9 +/- 0.4). In the patients with PCOS, no correlation was observed between PI and luteinizing hormone, testosterone or androstenedione levels. Obesity had no effect on uterine artery PI, with no significant differences in this index when the 3 groups were subdivided into obese and non-obese groups.

Effect of transitory hyperprolactinemia on in vitro fertilization of human oocytes

OBJECTIVE

To examine the changes in plasma prolactin (PRL) during ovarian hyperstimulation (OH) and the influence of hyperprolactinemia on folliculogenesis, oocyte retrieval and in vitro fertilization (IVF) success rates and the usefulness of the metoclopramide (MCP) test in predicting the onset of hyperprolactinemia.

STUDY DESIGN

Forty-nine cycles of OH were induced in 32 infertile women using follicle-stimulating hormone, human menopausal gonadotropin and human chorionic gonadotropin (GI) (n = 36), also in association with gonadotropin-releasing hormone (GII) (n = 13). The MCP test (10 mg, intravenously) was performed on fertile control women (control group, n = 9) and in GI (n = 21) and GII (n = 8) patients.

RESULTS

Plasma PRL and estradiol levels increased during OH, reaching maximum levels on the day preceding oocyte retrieval in GI and GII. Since these two groups exhibited similar PRL curves, they were evaluated as a single group. Patients showing an increase in PRL of > 200% presented a greater number of follicles with a mean diameter > or = 12 mm and more mature oocytes and better IVF success rates than patients with a PRL increase < or = 200%. Oocyte retrieval did not differ between the groups. The MCP test showed hyperresponsiveness in the three groups studied, but no correlation was found between the PRL increase in this test and that during OH.

CONCLUSION

Plasma PRL and estradiol levels increase during OH, while the MCP test cannot predict the onset of hyperprolactinemia. Transitory hyperprolactinemia seems to be associated with an increase in the numbers of follicles with a mean diameter > or = 12 mm and with more mature oocytes and better IVF success rates.

Incidência de cesáreas segundo fonte de financiamento da assistência ao parto

OBJETIVO: Estudar os tipos de partos de acordo com a categoria de internação da paciente, bem como as indicações de cesarianas mais freqüentemente referidas. MÉTODOS: A partir dos dados de um sistema de informações hospitalares, foi feita uma análise retrospectiva dos partos ocorridos no município de Ribeirão Preto, São Paulo, Brasil, no período de 1986-1995. Foram estudados: tipo de parto, categoria de admissão e diagnósticos referidos. RESULTADOS: Ocorreram 86.120 partos no período estudado, sendo 5,4% na categoria privada, 28,7% na categoria de pré-pagamento e 65,9% no sistema público (Sistema Único de Saúde -- SUS), observando-se uma diminuição nas categorias privada e SUS e aumento na categoria de pré-pagamento. A percentagem de cesáreas aumentou de 68,3% para 81,8% na categoria privada e de 69,1% para 77,9% na categoria pré-pagamento e diminuiu de 38,7% para 32,1% na categoria SUS. As principais indicações cesarianas referidas foram o sofrimento fetal, cujas incidências foram 9,5%, 10,9% e 9,0%, respectivamente, nas categorias particular, pré-pagamento e SUS; e distócia céfalo-pélvica cujas taxas foram 5,8%, 6,5% e 3,9%, respectivamente, nas mesmas categorias mencionadas. CONCLUSÃO: A incidência de cesariana variou segundo a categoria de internação, observando-se um gradiente crescente à medida que se elevou o padrão social das gestantes, não havendo correspondência com o risco obstétrico.

Prenatal diagnosis of fetal ovarian hyperstimulation

A case of prenatal diagnosis of fetal ovarian hyperstimulation in a pregnancy of 35 weeks is reported. Two large cystic septate ovaries with no internal vegetations were observed in the fetal abdomen. The fetus was macrosomic and the remaining morphology was normal. Polyhydramnios and placental thickening were present, with no other macro- or microscopic alterations. The only significant maternal change detected was elevation of blood beta-human chorionic gonadotropin (beta-hCG) levels. Evaluation of the newborn confirmed the prenatal diagnosis, with progressive and spontaneous regression of fetal ovarian volume and of maternal serum beta-hCG occurring after delivery.

Induction of ovulation with clomiphene citrate in combination with metoclopramide in patients with amenorrhea of hypothalamic origin

Literature data have demonstrated that the chronic use of metoclopramide (MCP), a dopamine antagonist, causes increased gonadotropin secretion in patients with hypothalamic amenorrhea but without triggering ovulation. It has also been observed that women with hypothalamic amenorrhea respond poorly to ovulation induction with clomiphene citrate (CC). On this basis, the objective of the present study was to determine the effect of MCP on the response to CC in patients with hypothalamic amenorrhea in order to evaluate the validity of the simultaneous use of these drugs as ovulation inducers in this type of chronic anovulation. Twenty-two patients with amenorrhea of hypothalamic origin were submitted to a randomized double blind study in which one tablet of 5 mg MCP or placebo was administered every 8 hours for 2 months. After the 30th day of medication (MCP or placebo), CC, 100 mg orally, was additionally administered to both groups for 5 days. Blood samples were collected on days 1, 15 and 30 during the first month of the study and on days 7, 14 and 21 after the last CC tablet during the second month, for later measurement of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, estradiol and progesterone by radioimmunoassay. The group that received MCP showed a significant increase in LH and FSH during the first month of the study, as well as a slighter increase in estradiol. Prolactin increased only during the second stage of treatment. No significant increases in gonadotropins, prolactin or estradiol occurred in the placebo group. In the group treated with MCP, 40% of the patients ovulated after CC, with menstruation occurring in 60% of them. In the placebo group, 33.3% of the women ovulated after CC and 44.4% menstruated at the end of the study. We conclude that MCP increases the circulating levels of LH, FSH, estradiol and prolactin in patients with hypothalamic amenorrhea and low estrogen levels, supporting the hypothesis that an increase in hypothalamic dopaminergic tonus occurs in these patients. On the other hand, the combination of MCP and CC does not improve the rate of ovulation compared to placebo.

Cortisol levels alter the response to metoclopramide in patients with hypothalamic amenorrhea

The reduction in frequency and/or amplitude of gonadotropin-releasing hormone (GnRH) pulses in patients with amenorrhea of hypothalamic origin has been attributed to increased dopamine activity. The objective of the present study was to determine the role of dopamine in the pathogenesis of hypothalamic amenorrhea. Fourteen patients with hypothalamic amenorrhea, nine of whom had psychogenic amenorrhea and five anorexia nervosa, were studied and compared with nine normal women during the early follicular phase. Metoclopramide (10 mg), a dopamine antagonist, was infused intravenously and blood samples were collected at 15-min intervals for 2 h for follicle-stimulating hormone (FSH) and luteinizing hormone (LH) measurement by radioimmunoassay. Both the hypothalamic amenorrhea (psychogenic amenorrhea and anorexia nervosa) and control groups were unresponsive to FSH, suggesting that dopamine may have little or no effect on FSH secretion. Five patients of the psychogenic amenorrhea group responded to LH (responsive psychogenic amenorrhea) and four did not (non-responsive psychogenic amenorrhea). No anorexia nervosa or control patient responded to the stimulus. Responsive psychogenic amenorrhea patients showed decreased basal cortisol levels compared to the non-responsive psychogenic amenorrhea and anorexia nervosa groups. It is possible that patients with exclusive alterations in the dopaminergic system are those who respond to metoclopramide (responsive psychogenic amenorrhea group), whereas patients who also have involvement of the hypothalamic-adrenal axis like the women with anorexia nervosa, are not responsive to metoclopramide and tend to have elevated cortisol levels. The non-responsive psychogenic amenorrhea group, with elevated cortisol levels, probably represents an intermediate step between the responsive psychogenic amenorrhea and anorexia nervosa patients.

Heart murmur in pediatrics: innocent or pathologic?

In a sample of 256 children referred to the São Paulo Hospital for consultation because of heart murmurs the incidence of innocent murmur was 41%. A clinical history and physical examination was performed in every child. The diagnosis was confirmed without the use of laboratory tests in only 5.5% of the cases: 32% of the children were submitted to chest x-ray and electrocardiogram; an echocardiogram had to be performed in 61% of the children and in 1.1% the catheterism was necessary to make the diagnosis. In the great majority of children with high suspicion of innocent murmur a good history and physical examination will suffice to confirm the diagnosis. If heart disease is suspected, laboratory tests should be performed for further evaluation. Any physician should be able to distinguish between pathologic and innocent murmurs based on their clinic features. The authors present a short review about the subject.