Tuberous sclerosis complex without tubers and subependymal nodules: a phenotype-genotype study.

Tuberous sclerosis complex (TSC) is caused by a mutation in the TSC1 or TSC2 genes. However, 15% of patients have no mutation identified. Tubers and subependymal nodules (SENs) are the typical brain lesions in TSC and are present in 90-95% of patients. The objective of this study is to characterize the specific genotype-phenotype of patients without these lesions. We analyzed the features of 11 patients without typical TSC neuroanatomic features. Ten had TSC1/TSC2 mutational analysis, which was negative. Clinically they had lesions thought to be of neural crest (NC) origin, such as hypomelanotic macules, facial angiofibromas, cardiac rhabdomyomas, angiomyolipomas, and lymphangioleiomyomatosis. We hypothesize that patients without tubers and SENs reflect mosaicism caused by a mutation in TSC1 or TSC2 in a NC cell during embryonic development. This may explain the negative results in TSC1 and TSC2 testing in DNA from peripheral leukocytes.

Tuning microcavities in thermally rearranged polymer membranes for CO2 capture.

Microporous materials have a great importance in catalysis, delivery, storage and separation in terms of their performance and efficiency. Most microporous materials are comprised of inorganic frameworks, while thermally rearranged (TR) polymers are a microporous organic polymer which is tuned to optimize the cavity sizes and distribution for difficult separation applications. The sub-nano sized microcavities are controlled by in situ thermal treatment conditions which have been investigated by positron annihilation lifetime spectroscopy (PALS). The size and relative number of cavities increased from room temperature to 230 °C resulting in improvements in both permeabilities and selectivities for H(2)/CO(2) separation due to the significant increase of gas diffusion and decrease of CO(2) solubility. The highest performance of the well-tuned TR-polymer membrane was 206 Barrer for H(2) permeability and 6.2 of H(2)/CO(2) selectivity, exceeding the polymeric upper bound for gas separation membranes.

A quest for cytocompatible metal organic frameworks in non-viral gene therapy: Relevance of zeolitic imidazolate framework-8.

Metal-organic frameworks (MOFs) are an emerging group of nanomaterials for successful biomedical applications in gene therapy. The most commonly biocompatible MOFs are zinc-based ZIFs, zirconium-based UiOs, and iron-based MILs. However, despite increasing applications, a comparative study to underscore the critical factors for determining effective gene delivery by such MOFs is lacking. Herein, we evaluate the potential of UiO-66 and MIL-88B and ZIF-8 for gene therapeutics delivery; revealing the comparative importance of ZIF-8. Cytotoxicity assays proved insufficient for selecting the ideal gene delivery MOF vehicle. Synthesis conditions such as ability of the MOF scaffold to envelop the gene during in-situ synthesis, post-treatment such as washing, and gene loading efficiency proved to be the critical factors in determining the favourable MOF from the material selection perspective. Rapid in-situ synthesis under physiological conditions, successful gene loading, and low concentration requirements favour ZIF MOFs as gene delivery vehicles. Impact on cellular physiology, metabolism, and architecture revealed neutrality of the delivery system; and relative effects on pro-inflammatory and anti-inflammatory cytokines suggest immunomodulatory impact.

Porosity in metal-organic framework glasses.

The porosity of a glass formed by melt-quenching a metal-organic framework, has been characterized by positron annihilation lifetime spectroscopy. The results reveal porosity intermediate between the related open and dense crystalline frameworks ZIF-4 and ZIF-zni. A structural model for the glass was constructed using an amorphous polymerization algorithm, providing additional insight into the gas-inaccessible nature of porosity and the possible applications of hybrid glasses.

Characterization of two second messenger pathways and their interactions in eliciting the human sperm acrosome reaction.

The human sperm acrosome reaction (AR) occurs via the activation of at least two signal transduction pathways. The purpose of this investigation was to characterize two of the pathways, the protein kinase A (PKA) and C (PKC) pathways, and determine whether pathway "crosstalk" occurs between them in eliciting the AR in capacitated spermatozoa. Stimulators of each pathway were tested in a dose-dependent manner. ARmax, ED50, and delta ARmax (%ARmax-%ARcontrol) values were calculated. The PKA pathway stimulators forskolin and dibutyryl cyclic AMP (dbcAMP) induced an ARmax at 1.0 microM and 1.0 mM, respectively. The ED50 and delta ARmax values were: 0.01 microM and 17% for forskolin and 0.069 mM and 13% for dbcAMP. Two stimulator types of the PKC pathway were tested: synthetic diacylglycerols (DG) and a phorbol diester. 1,2-dioleoyl-sn-glycerol and 1,2-dioctanoyl-sn-glycerol, analogues of the PKC-activating second messenger DG, each induced an ARmax at 50 microM. The ED50 and delta AR max values were: 33 microM and 24% for 1,2-dioleoyl and 34.8 microM and 34% for 1,2-dioctanoyl. 4 beta-Phorbol-12,13-didecanoate, a PKC stimulator, induced an ARmax at 0.1 microM. The ED50 and delta ARmax were 0.021 microM and 26%. An inhibitor of each kinase was added at the end of the capacitation period and prior to stimulation by inducers at their ARmax dose. KT5720, a PKA inhibitor, caused a dose-dependent reduction of the forskolin and dbcAMP-induced AR. Calphostin C, a PKC inhibitor, prevented stimulation of the AR by 1,2-dioleoyl and 4 beta-phorbol-12,13-didecanoate. To investigate pathway "crosstalk," the following experiments were conducted: (1) stimulators of each pathway were combined and tested at the ARmax and ED50 concentrations for each; (2) spermatozoa were pretreated with a kinase inhibitor and then stimulated using an alternative pathway stimulator; and (3) a PKA or PKC inhibitor and a combination of PKA and PKC stimulators, at ED50 concentrations, were tested. The results for (1) indicate an additive AR response of ED50 concentrations but not for ARmax doses. The results for (2) demonstrate that a kinase inhibitor for one pathway prevents induction of the AR by a stimulator of the alternative pathway. Finally, the results for (3) show that a kinase inhibitor for one pathway prevents induction of the AR by the combined use of separate pathway stimulators. When taken collectively, the present results suggest a convergent mechanism of crosstalk between the PKA and PKC pathways leading to the human sperm AR.

Management of thyroid nodules during pregnancy.

Guidelines for the management of thyroid nodules discovered during pregnancy have not yet been established. The authors reviewed the records of 23 patients with thyroid nodules that were first detected during pregnancy. These patients were divided into three groups according to how they were managed. Seven patients who presented early in pregnancy had their work-up completed during pregnancy, 11 patients underwent biopsy after delivery, and 5 patients were managed with observation alone. The incidence of malignancy in the series was 39%. Four patients underwent surgery during pregnancy, and 7 patients were operated on in the postpartum period. No fetal morbidity or mortality occurred. The authors recommend that fine-needle aspiration be performed in patients who present before 20 weeks of gestation with rapidly enlarging thyroid nodules, nodules associated with palpable cervical adenopathy, solid nodules larger than 2 cm, or cystic nodules larger than 4 cm. Growth of a nodule while a patient is receiving thyroid hormone suppression therapy is highly suspicious for malignancy; in this situation, consideration should be given to performing biopsy later in gestation.

Increase in titer of the naturally occurring human antibody to neuraminidase-treated lymphocytes after influenza.

Nine of 25 (36%) humans suffering from naturally acquired influenza A infection developed significant increases in the titer of a "naturally" occurring antibody to neuraminidase-treated human lymphocytes. Only two of 43 normal and noninfluenza respiratory infection controls showed titer changes of this antibody, p less than 0.001. The antibody was not directed at influenza virus C fixation, hemagglutination inhibition, or neuraminidase antigens. Three of 10 normals given a highly immunogenic, formalin-killed influenza A vaccine developed significant titer rises. These results suggest that influenza virus, live or dead, can provoke an increase in antibody to a cross-reacting antigen present on neuraminidase-treated human lymphocytes.

Transvaginal ultrasonography and the assessment of luteal phase endometrium.

OBJECTIVE: The goal of this study was to determine if ultrasonography of the endometrium could be used to identify in a noninvasive manner patients with luteal phase defects. STUDY DESIGN: Patients underwent midluteal transvaginal ultrasonography with photographing of the endometrial image, an endometrial biopsy, and two serum hormonal profiles. The ultrasonographic images were graded and compared with the histologic results and the serum hormonal profiles. RESULTS: There was a trend toward a higher grade image being associated with normal histologic studies. There was no significant difference between the mean hormonal profiles in patients with normal and those with abnormal biopsy specimens. There was no significant difference between the hormonal values drawn before and those drawn after the biopsies. CONCLUSIONS: Although the endometrial appearance on ultrasonography appears to reflect secretory transformation, it cannot replace endometrial biopsy for full evaluation of luteal endometrial development. Short-term variability in serum concentrations of midluteal hormones was not demonstrated.