Damage localization in piezo-ceramic using ultrasonic waves excited by dual point contact excitation and detection scheme.

A novel experimental technique based on point contact and Coulomb coupling is devised and optimized for ultrasonic imaging of bulk and guided waves propagation in piezo-ceramics. The Coulomb coupling technique exploits the coupling and transfer of electric field to mechanical vibrations by excitation of phonons. The point contact excitation and detection technique facilitates the spatial-temporal imaging of ultrasonic waves. The motivation of this research is the diagnosis and localization of surface cracks in the piezoelectric sensors and actuators. The underlying principle of the detection scheme is that any discontinuity on the surface causes high localization of electric gradient. The localized electric field at the defect boundaries enables then to behave as secondary passive ultrasonic sources resulting in strong back reflections. However, due to the interference between transmitted and reflected wave components from rigid boundaries and defect, the resolution on the localization of the damage is challenging. Therefore, an algorithm based on the two-dimensional spectral decomposition is utilized for selective suppression of the transmitted wave. The algorithm includes data transformation and vectorization in polar coordinates for efficient spectral decomposition. In the spectral domain, the complex wave component (phase and amplitude) are suppressed for the transmitted wave field. The reflected wave component in the spectral domain is retained and retrieved back using inverse spectral transformation. The algorithm is successful in retaining and exemplifying only the reflected wave sources arising from the strong scattering of ultrasonic waves from the surface and sub-surface defects. In summary, a novel experimental technique based on Coulomb coupling and spectral decomposition technique has been implemented for localization of surface defect in piezo-ceramic structures.

Traumatic and spontaneous carotid and vertebral artery dissection in a level 1 trauma center.

This study aimed to compare traumatic and spontaneous carotid artery dissection (CAD) and vertebral artery dissection (VAD) with respect to age, pre-morbid risk factors, and site of dissection. Chart review was performed for 49 patients with CAD and VAD admitted to Westchester Medical Center, a level 1 trauma center, from 1999 to 2007. Presentation was categorized into traumatic (n=28, 57%) or spontaneous dissection (n=21, 43%). Pre-morbid risk factors were analyzed. Location of dissection was identified and categorized into four possible segments. Patients with spontaneous dissection were likely to be over the age of 50 years (p<0.05), and had significantly higher proportions of coronary artery disease (33% compared to 7%, p<0.05), hypertension (57% compared to 18%; p<0.01), and hypercholesterolemia (29% compared to 0%; p<0.01). Of the 49 patients, 42 had imaging studies available for segmental analysis. In both traumatic CAD and VAD, dissection at Segment III (corresponds with the first and second cervical vertebrae), was the most common site (37.5% and 50%, respectively, p<0.05). In contrast, Segment I (origin of the vessel to the fifth cervical vertebrae) was the most common site for spontaneous CAD and VAD (55% and 77%, respectively, p<0.05). This cross-sectional study suggests that etiology plays an important role in the location of dissection. Traumatic CAD and VAD occur most commonly in Segment III. Spontaneous CAD and VAD occur most commonly in Segment I and are associated with increasing age and premorbid cerebrovascular risk factors.

Selective generation of high-order optical vortices from a single phase wedge.

We demonstrate that it is possible to generate high-order optical vortices from a single phase wedge by applying an incident beam with an annular intensity distribution. Various topological charges of optical vortices are realized by a static phase wedge when the position and radius of the annular illumination are changed accordingly.

Design and fabrication of a double-axicon for generation of tailorable self-imaged three-dimensional intensity voids.

We propose a new design for fabrication of a highly power-efficient double axicon to generate self-imaged three-dimensional intensity voids along the propagation of a beam. The conventional conical structure of an axicon is modified and shaped like an axiconlike structure with a double-gradient surface profile. The gradient conical surfaces generate Bessel beams with varying radial wave vectors that are superimposed and interfere to generate a sequence of three-dimensional intensity voids. The proposed element was fabricated using electron-beam lithography, and experimental verification of the design is reported.

High-power efficient multiple optical vortices in a single beam generated by a kinoform-type spiral phase plate.

We propose using a solitary kinoform-type spiral phase plate structure to generate an array of vortices located in a single beam. Kinoform-type spiral surfaces allow each wavelength component of the phase modulation value to be wrapped back to its 2 pi equivalent for optical vortices of high charge. This allows the surface-relief profiles of high-charge vortices to be microfabricated with the same physical height as spiral phase plates of unity-charged optical vortices. The m-charged optical vortex obtained interacts with the inherent coherent background, which changes the propagation dynamics of the optical vortex and splits the initial m charge into /m/ unity-charged optical vortices within the same beam. Compared to a hologram, a multistart spiral phase plate is more efficient in the use of available spatial frequencies and beam energy and also is computationally less demanding. Furthermore, using microfabrication techniques will allow for greater achievable tolerances in terms of smaller feature sizes.

Giant petrous carotid aneurysm treated by submandibular carotid-saphenous vein bypass. Case report.

Petrous and cavernous sinus carotid artery (CA) aneurysms that are not amenable to clip ligation or endovascular therapy may be successfully treated by a saphenous vein bypass, thereby preserving the patency of the CA. The authors report the unique case of a 47-year-old man with a giant fusiform aneurysm of the petrous CA, who presented with a rapid onset of a lateral rectus palsy and diplopia. The lesion was treated by trapping the aneurysm and performing a saphenous vein bypass from the cervical to the intracranial CA. The saphenous vein graft was routed beneath the condyle of the mandible to reduce the overall length of the graft, thereby increasing the likelihood of long-term patency and offering protection to the graft by the mandible, temporal muscle zygomatic process, and masseter and temporal muscles. The presentation and technical aspects of the bypass graft in this unique case are discussed.

Constitutive expression of the steroid sulfatase gene supports the growth of MCF-7 human breast cancer cells in vitro and in vivo.

Many human breast tumors are driven by high intratumor concentrations of 17beta-estradiol that appear to be locally synthesized. The role of aromatase is well established, but the possible contribution of the steroid sulfatase (STS), which liberates estrogens from their biologically inactive sulfates, has been inadequately assessed and remains unclear. To evaluate the role of STS further, we transduced estrogen-dependent MCF-7 human breast cancer cells with a retroviral vector directing the constitutive expression of the human STS gene. Gene integration was confirmed by Southern hybridization, production of the appropriately sized messenger RNA by Northern hybridization, and expression of functional protein by metabolism of [(3)H]estrone sulfate to [(3)H]estrone. Maximum velocity estimates of estrone formation are 64.2 pmol estrone/mg protein.h in STS-transduced cells (STS Clone 20), levels comparable to those seen in some human breast tumors. Lower levels of endogenous activity are seen in MCF-7 cells (13.0 pmol estrone/mg protein.h) and in cells transduced with vector lacking the STS gene (Vector 3 cells; 12.0 pmol estrone/mg protein.h). 17beta-Estradiol sulfate induces expression of the progesterone receptor messenger RNA only in STS Clone 20 cells, whereas estrone sulfate produces the greatest stimulation of anchorage-independent growth in these cells. STS Clone 20 cells retain responsiveness to antiestrogens, which block the ability of estrogen sulfate to increase the proportion of cells in both the S and G(2)/M phases of the cell cycle. Consistent with these in vitro observations, only STS Clone 20 cells exhibit a significant increase in the proportion of proliferating tumors in nude ovariectomized mice supplemented with 17beta-estradiol sulfate. The primary activity in vivo appears to be from intratumor STS, rather than hepatic STS. Surprisingly, 17beta-estradiol sulfate appears more effective than 17beta-estradiol when both are administered at comparable concentrations. This effect, which is seen only in STS Clone 20 cells, may reflect differences in the cellular pharmacology of exogenous estrogens compared with those released by the activity of intracellular STS. These studies directly demonstrate that intratumor STS activity can support estrogen-dependent tumorigenicity in an experimental model and may contribute to the promotion of human breast tumors.

Alcohol modulates cytokine secretion and synthesis in human fetus: an in vivo and in vitro study.

It is well recognized that alcohol passes through the placenta and affects the fetal immune system. The underlying mechanism accounting for immune suppression is not clear. Cytokines are recognized as the principal mediators of a variety of immunologic and pathophysiologic events. The study was designed to examine whether alcohol use during pregnancy affects cytokine synthesis and secretion in the human fetus. Fetal (cord blood) and mother's blood were used for the study. Studies were conducted in vivo and in vitro. For the in vivo study, cytokine levels were measured in cord blood in mothers who drank moderate to heavy (chronic) amounts of alcohol during pregnancy. For the in vitro study, cord blood was obtained from mothers who were drug-free throughout pregnancy. Lymphocytes were isolated and stimulated with lipopolysaccharide (LPS; Escherichia coli, 26:B6). The capacity of lymphocytes to synthesize cytokines was examined in the presence of 20, 50, and 100 mM alcohol. Among the cytokines examined were the tumor necrosis factor (TNF alpha) and interleukins (IL-1 alpha and beta and IL-6). The selection of cytokines was based on their presumptive role in the pathophysiology of alcoholism. Cytokines were measured by using a specific immunoassay. When data obtained from moderate alcohol users were compared with those obtained from nonusers, no significant differences were observed in any of the cytokines examined (p>0.05). In chronic alcohol users, levels for all cytokines increased significantly (p<0.001) in both the fetus and the mother. Among the cytokines, IL-1beta, IL-6, and TNFalpha were the predominant cytokines affected by chronic use of alcohol during pregnancy. The order of stimulation was IL-6, IL-1 beta, TNFalpha, and IL-1 alpha in descending order. In the in vitro study, alcohol blunted LPS stimulation of cytokines, and the alcohol-induced decrease in cytokine synthesis was proportional to the level of alcohol in the media, suggesting a direct effect of alcohol on cytokine synthesis. In general, the blunting effect of alcohol on LPS stimulation was more prominent in the fetus compared with that in mother. We conclude that chronic alcohol use during pregnancy stimulated the fetal cytokine synthesis and secretion, and IL-1beta, IL-6, and TNF alpha were the predominant cytokines affected by alcohol. The in vitro data suggest a direct effect of alcohol on cytokine synthesis.

Low levels of ethanol stimulate and high levels decrease phosphorylation in microtubule-associated proteins in rat brain: an in vitro study.

Phosphorylation and dephosphorylation of proteins associated with microtubules (MAPs) modulate the functional properties of microtubules (MT). A study was designed to test the hypothesis that ethanol at pharmacologically relevant levels affects phosphorylation of MAPs. Low (6, 12, 24, and 48 mM) and high (96, 384, and 768 mM) levels of ethanol were used in the study. MT prepared from rat brain by successive cycles of assembly-disassembly were found to contain two high molecular weight proteins (MAP2 and MAP1), tubulin, and 70-kDa neurofilament. The kinase activity was determined using [gamma(32)P]ATP as a phosphate donor. The results showed that ethanol primarily stimulated MAP2 phosphorylation. Low levels of ethanol stimulated, whereas high levels decreased, the kinase activity. MAP1 was phosphorylated to a lesser extent. 70-kDa neurofilament and tubulin were phosphorylated, however, the dose-dependent biphasic effect of ethanol on phosphorylation was not found in these cytoskeleton proteins. To determine whether the ethanol-induced kinase activity was cAMP-dependent, the catalytic subunit of cAMP-dependent protein kinase was isolated, purified, and kinase activity was determined with and without ethanol. The results showed that cAMP was not involved in ethanol-induced kinase activity. We conclude that ethanol predominantly stimulates phosphorylation of MAP2 in a dose-dependent manner.

Alcohol inhibits cell mitosis in G2-M phase in cell cycle in a human lymphocytes in vitro study.

Alcohol abuse is associated with the loss of immunocompetence, which leads to decreasing resistance to infections. No single mechanism can be accountable for the detrimental effects of alcohol on the body's defense mechanism. We present data demonstrating that, in cultured lymphocytes, 10-40 mM alcohol in the media caused 18-90% decrease in cell mitosis (p < 0.001). There was a linear decrease in cell mitosis upto 40 mM alcohol; at 100 mM cell mitosis virtually ceased. This study aimed to determine in which phase of the cell cycle did alcohol mediate its effects. The results showed that DNA synthesis was not affected with up to 50 mM alcohol, suggesting that G1-S phase in the cell cycle remained unaffected. At 100 mM alcohol, DNA synthesis decreased significantly (p < 0.01). From the results of this study, we conclude that a subpharmacological dose level of alcohol (10 mM) significantly inhibited cell mitosis and the inhibitory effect of alcohol was mediated in the G2-M phase in the cell cycle. The G1-S phase was unaffected.

Evaluation of subconjunctival anaesthesia vs peribulbar anaesthesia in cataract surgery.

A comparative study was carried out to evaluate peribulbar anaesthesia (group A) vs subconjunctival anaesthesia (group B). The results proved peribulbar anaesthesia to be more effective than subconjunctival anaesthesia as regards orbicularis akinesia (p < 0.05) and ocular akinesia (p < 0.05). There was no significant difference in the sensory anaesthesia, analgesia and intraocular pressure changes in the two groups (p > 0.05). Block assessment was ideal in 80% of patients in group A in comparison to 51% in group B (p < 0.05), and unsatisfactory in 14% in group A and 30% in group B (p < 0.05). Further, no significant complications were observed with peribulbar anaesthesia. Therefore, we conclude that peribulbar anaesthesia should be preferred over subconjunctival anaesthesia for conventional extracapsular cataract extraction with or without intraocular lens implantation.

Total bone mineral content and body composition by x-ray densitometry in newborns.

Measurement of total body bone mineral content and body composition has not previously been convenient in the newborn. X-ray densitometry, otherwise known as dual-energy x-ray absorptiometry (DEXA), has been used in adults to assess with accuracy and precision the total body mineral content, lean mass, and fat. Body composition measurements were determined in vivo by DEXA in term newborns, and they were compared with values reported by chemical analysis of the cadaver, with skin-fold thickness measurements, and with bone mineral content measured by single photon absorptiometry. The intermeasurement coefficient of variation was < or = 2.5% for bone mineral content, and < or = 1% for fat and lean mass. The values for bone mineral content, fat, and lean mass fall within the ranges expected based on the reported values measured by chemical analysis of the infant cadaver. Triceps and quadriceps skin-fold measurements were best correlated with total body fat as measured by DEXA. The bone mineral content of the distal third radius site as measured by single photon absorptiometry in newborns showed significant correlation with total body bone mineral content. DEXA provides a reproducible and convenient method for the determination of body composition in newborns.

Ethanol decreases progesterone synthesis in human placental cells: mechanism of ethanol effect.

Fetal alcohol syndrome (FAS) is a set of signs and symptoms in offsprings born to mothers who abuse alcohol during pregnancy. We postulated that impairment in the placental endocrine function contribute to FAS. In this study, we examined in vitro effects of ethanol on the placental cells' (cytotrophoblast cells) capacity to synthesize progesterone. Cytotrophoblast cells were isolated from normal term placenta and were incubated (2 x 10(6)) with 20-, 30-, and 40-mM doses of ethanol for 6 h. Progesterone was measured in the incubate by RIA. The results showed that, at the 20-mM dose of ethanol, progesterone synthesis was significantly decreased (p less than 0.01), at the 30-mM dose level there was a further decrease of 20%. The differences between 30- and 40-mM ethanol dose levels were not significant. To determine the mechanism of ethanol effects on progesterone synthesis, cytotrophoblast cells were preincubated with 30 mM ethanol followed by 10 microliters of LDL (10 microliters LDL = 80 micrograms cholesterol) and vice versa. The results showed that ethanol effects on progesterone synthesis was dependent on whether ethanol was added prior to or following the addition of LDL in the medium. If ethanol was added in the medium prior to LDL, progesterone synthesis was decreased significantly (p greater than 0.01); however, when ethanol was added after the LDL, ethanol had no effect on progesterone synthesis. In the experiment where ethanol and LDL were added simultaneously in the medium, ethanol blunted the stimulatory effect of LDL on progesterone synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Biphasic protein kinase C translocation in PC12 cells in response to short-term and long-term ethanol exposure.

Short-term and long-term effects of ethanol on protein kinase C (PKC) activity and PKC translocation from cytosol to membrane were examined in PC12 cells, a clonal cell line of neural crest origin. Treatment of PC12 cells with ethanol (30-100 mM) for 2 hr had no effect on PKC activity and PKC translocation. When PC12 cells were treated with 100 mM ethanol for 18, 44 and 74 hr, there was a biphasic effect on PKC translocation. At 18 and 44 hr ethanol treatment, PKC translocation was significantly (P < 0.001) increased, at 74 hr ethanol treatment, there was a significant decrease (P < 0.05). Less than 100 mM of ethanol had no effect on PKC activity and PKC translocation. Cyclic AMP and cyclic GMP-dependent protein kinase had no effect on PKC translocation. These findings indicate that biphasic PKC translocation from cytosol to membrane forms the basis of acute and chronic effects of ethanol on neurotransmission.

Tear film profile in Graves' ophthalmopathy.

Tear film profile was studied in 30 patients with Graves' ophthalmopathy. Tear film pH, fluorescein staining, marginal tear strip and Schimer test values in patients with Graves' ophthalmopathy were comparable with controls, indicating normal tear secretion. Tear film break-up-time (BUT) in late Graves' ophthalmopathy was significantly low suggesting unstable tear film. Rose bengal as well as lissamine green staining intensity scores were significantly high, indicating presence of drying epithelial cells in early as well as late Graves' ophthalmopathy patients.

A clinico-investigative profile in Graves' ophthalmopathy.

A clinico-investigative profile was studied in 30 patients with Graves' Ophthalmopathy (GO) (15 each with early and late). In accordance to the thyroid status 63.3% of patients were hyperthyroid and 36.7% euthyroid. There was slight female preponderence, with ratio being 1.5:1. Exophthalmometric readings were significantly high in GO patients as compared to controls. However, no significant diagnostic role of postural exophthalmometry was seen. Positional tonometery may have respectable place among the tests for early diagnosis of GO; however, it could not differentiate between hyperthyroid and euthyroid cases. Further the role of ultrasonography, if available could not be overemphasized.

An experimental model of oculorespiratory reflex.

An experimental study of the oculorespiratory reflex (ORR) was conducted on 20 albino rabbits using a square wave (SW) type of stimulus. The ORR could be elicited in 100% of animals. The medial rectus was observed to be most reflexogenic for ORR. The frequency and pattern of ORR was not affected by bilateral vagotomy, intravenous atropine or glycopyrrolate, but could be completely abolished by retrobular block.

Amniotic fluid and umbilical artery levels of sex hormones and prostaglandins in human cocaine users.

Biochemical evaluation of amniotic fluid contents is often used to monitor fetal secretory and excretory functions. To determine whether cocaine use during pregnancy affects fetal endocrine secretions, amniotic fluid and umbilical artery samples were collected at term, and selected gonadal hormones and prostaglandins were assayed. Gestational age, birth weights, and placental weights were recorded. The data showed that birth weights were significantly decreased (P less than 0.001) in cocaine users, but gestational age and placental weights were unaffected. Amniotic fluid levels of androstenedione and testosterone were decreased (P less than 0.05) in males born to cocaine users; females were not affected. Prostaglandins (PGF2 alpha and PGE2) were significantly increased (P less than 0.01) in cocaine users. In the umbilical artery, follicle-stimulating hormone was increased (P less than 0.01) in males and females, while luteinizing hormone was increased (P less than 0.01) only in males. We conclude that cocaine passes through the placenta and affects the fetal testes-hypophyseal endocrine system.

Bilateral proptosis due to metastatic Ewing's sarcoma of the orbit: fine needle aspiration cytology (FNAC) and histopathology of a case.

Bilateral proptosis due to metastatic Ewing's sarcoma is an extremely rare presentation and thus merits reporting. The role of fine needle aspiration cytology in the diagnosis is highlighted.