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.

Giant petrous carotid aneurysm treated by submandibular carotid—saphenous vein bypass

✓ 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 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.

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.

Subdural empyema--an unusual presentation. A report on 2 cases

Two cases of subdural empyema with unusual clinical features are described. Both had an undetermined primary source of infection, the onset was insidious and the course was rather indolent, and both cases occurred after steroid therapy. Subdural empyema is a potentially lethal condition if inappropriately managed. A high index of suspicion and prompt definitive treatment remain the cornerstones of successful management. The aetiology and pathogenesis of subdural empyema and the merits and demerits of various investigative procedures are discussed; the factors that influence prognosis are highlighted.

Dexamethasone suppresses sex-hormone binding globulin

Dexamethasone suppression (DEX-S) for 14 days has been used to determine the probable source of androgen excess. The exact mechanism(s) of DEX-S is still unclear. The authors postulated that dexamethasone (DEX) inhibits either the synthesis or secretion of sex-hormone binding globulin (SHBG). To examine this hypothesis, 14 women with polycystic ovarian disease (PCOD) and 3 volunteers were given DEX for 14 days. The PCOD group included obese and nonobese women (+/- 15% ideal body weight). Plasma determinations by radioimmunoassay of total testosterone, free testosterone, androstenedione, dehydroepiandrosterone sulfate, luteinizing hormone; follicle-stimulating hormone; cortisol, and SHBG were made. DEX suppressed SHBG levels (P less than 0.01). SHBG levels were significantly lower in the obese than in the nonobese (P less than 0.01). All androgens were suppressed by DEX, with the exception of androstenedione post-DEX levels, which were significantly greater than pre-DEX levels in 6 of 14 subjects (P greater than 0.05). This observation is consistent with DEX suppression of SHBG.

The effect of delta 9-tetrahydrocannabinol in utero exposure on rat offspring fertility and ventral prostate gland morphology

Male rats exposed in utero to delta 9-tetrahydrocannabinol (delta 9-THC) had lower levels of testosterone (T) and luteinizing hormone (LH) prior to puberty (P less than 0.01). At puberty, the levels returned to within the normal range. Ultrastructural examination of the ventral prostate gland at puberty revealed alterations suggestive of degenerative changes. A drastic reduction in secretory granules and acini reflected depressed androgen production and function during the developmental period. The fertility of the F1 and F2 male offspring was decreased by 30 to 40%. It is concluded that THC exposure in utero caused a permanent reduction in fertility and altered ventral prostate gland morphology.

Cervical mucus peroxidase is a reliable indicator for ovulation in humans

This study was designed to establish whether fluctuation in cervical mucus peroxidase concentration correlates with the cyclic pattern of the menstrual cycle hormones in the human female. Forty healthy, normal-cycling women between the ages of 19 and 29 years were chosen for the study. Blood samples and cervical mucus were collected on days 6, 9 through 15, and 17 through 19 of the menstrual cycle for three consecutive cycles in each volunteer. Blood estrogen, progesterone, follicle-stimulating hormone, and luteinizing hormone levels were quantitated by radioimmunoassay, and cervical mucus peroxidase concentrations were measured spectrophotometrically. The data showed that in the typical menstrual cycle the mucus peroxidase peak was reached immediately prior to the luteinizing hormone/follicle-stimulating hormone surge and coincided with the estrogen peak. Consistent data in three consecutive menstrual cycles in each volunteer led us to postulate that the mucus peroxidase peak during the menstrual cycle precedes the ovulatory period in the normal healthy woman.

Localization of retinol (vitamin A) in rat testes

The purpose of the study was to determine the intracellular location of exogenously injected labeled vitamin A (retinol) in rat testes by light and electron microscopic autoradiography. Tritium-labeled vitamin A mixed in vitamin A-free rat serum was injected intracapsularly in one testis in adult rats. At intervals of 30 minutes, 2 hours, and 4 hours following injection the treated testes were removed the processed for autoradiography. The results show that in the testes vitamin A is localized at three sites: within the macrophages of the interstitial tissue, in the lipid droplets of the Sertoli cells, and in the spermatids in association with Golgi saccules. To confirm the autoradiographic localization of vitamin A, the cellular retinol-binding protein (CRBP) assay demonstrates the presence of CRBP in the interstitial tissue and seminiferous tubules. The results of the study suggest a possible role of vitamin A in spermiogenesis in rat testes.

Methadone blocks dopamine-mediated release of gonadotropins in rat hypothalamus

In the present study the effect of methadone (M) on gonadotropin-releasing hormone in the rat hypothalamus was investigated. The specificity of the M effect was demonstrated by injecting M (100 ng) and the M antagonist, naloxone (5 ng), into the ventromedial hypothalamus. A significant drop in the blood testosterone level (p less than 0.05) 15 min following M injection and reversal following naloxone administration suggest a decrease in synthesis or release of LHRH. To determine whether the LHRH response to dopamine (DA) is altered by M, studies were conducted in vitro and in vivo. For the in vitro study hypothalami were incubated with M (10(-7) M), DA (10(-7) M), DA plus M, and DA plus M plus naloxone. Supernatants from the incubate were used to coincubate pituitaries in order to study the effect on luteinizing hormone release. Treatment of the hypothalamus with M had no effect on basal but inhibited the DA-stimulated release of LHRH. For the in vivo study rats were pretreated with decarboxylase inhibitor (RO4-4602) followed by treatment per kilogram body weight with M (10 mg), L-dopa (1, 10, and 100 mg), L-dopa plus M, LHRH (500 ng), and M plus LHRH. M had no effect on the LHRH-induced increase in testosterone levels, whereas the L-dopa-induced increase in testosterone was blunted by M treatment. It is concluded that M blocks the DA-mediated release of gonadotropin-releasing hormone in the rat hypothalamus.

Blood levels of ethynylestradiol, caffeine, aldosterone and desoxycorticosterone in hypertensive oral contraceptive users

Twenty normotensive and ten hypertensive black women taking oral contraceptive (OC) were studied. Age, body weight, family medical history of hypertension, length of OC use, and type of OC were comparable. At midcycle approximately 10-12 hours following OC intake, blood was drawn and the plasma was used to determine ethynylestradiol (EE2), caffeine, aldosterone (Aldo) and desoxycorticosterone (DOC) levels. The results showed that in hypertensive OC users, EE2 and caffeine levels were significantly higher (P less than .01) compared to normotensive OC users. While no significant differences were found in Aldo and DOC levels between hypertensive and normotensive OC users, OC users had higher levels of Aldo (P less than .01) compared to non-OC users.

Evidence of facilitory effect of growth hormone on tissue vitamin A uptake in rats

The proposed study was designed to investigate the effect of growth hormone (GH) on liver vitamin A release and uptake at the tissue level. Labeled vitamin A (retinol) was injected in hypophysectomized (hypox) rats, and plasma radioactivity was monitored at intervals for up to 6 hours and at 24 hours following injection. Controls (intact sham-operated) received similar treatment. The results showed that the radioactivity reached its maximum levels in both groups between the third and fourth hours following injection and declined thereafter at different rates in each group. At 24 hours following injection, plasma radioactivity in the intact rats was less than 10% of its maximum levels while in the hypox rats for the same time period it remained at 80--90% of its maximum levels. A single injection of GH at the third hour after injection in the hypox rats decreased significantly (P less than 0.01) plasma radioactivity while radioactivity in the testes and kidneys and in urine collected for the 24 hours increased significantly (P less than 0.01). Hypophysectomy had no effect of vitamin A absorption and liver vitamin A release to the blood. Also, hypophysectomy had no significant effect on plasma and tissue retinol-binding protein levels and its binding capacity to retinol. It is concluded that a facilitory effect of GH at the tissue level may be an important factor in vitamin A metabolism.

Characterization of prostatic carcinoma among blacks: a comparison between a low-incidence area, Ibadan, Nigeria, and a high-incidence area, Washington, DC

A comparison of carcinoma of the prostate gland in a low-incidence Nigerian (Ibadan) population and a high-incidence U.S. Afro-American (Washington, D.C.) population was the purpose for this study, initiated in 1973. The frequency of carcinoma (micro- and invasive) was determined in consecutive necropsy cases from hospitals in Ibadan, Nigeria, Accra, Ghana and Washington, D.C. The results of these clinical, epidemiologic and morphologic studies are reported. Clinically, the peak incidence of carcinoma of the prostate in Nigerian males in Ibadan and in American males in Washington, D.C. was in the 65-74 age group. The median age of patients was 66.4 years in Ibadan and 69.2 years in Washington, D.C. Seventy-five percent of Nigerian and 49% of American patients were in stages III and IV. Overall, the distribution by grade of neoplasms in surgical material from Ibadan and Washington, D.C. was similar. Plasma testosterone and estrone levels were significantly higher (p < 0.05 and p < 0.001) in U.S. patients than in U.S. controls and higher (p < 0.001 and p < 0.05) in U.S. patients than in Nigerian patients with prostatic carcinoma. Plasma testosterone levels were significantly lower (p < 0.05) in Nigerian patients than in Nigerian controls. Estrone levels were not significantly different in Nigerian patients than controls. Nigerian patients were more sexually active throughout their lives than American patients; however, they reported a higher incidence of impotence than U.S. patients in the immediate 5 years preceding the diagnosis of prostatic carcinoma. Nigerian respondents (patients and controls) arrived at puberty later than their American counterparts. Within each of the two population groups, the factor with the highest relative risk ratio was lower urinary tract symtoms occurring 10 years or longer before the onset of the present complaints which led to the diagnosis of prostatic carcinoma. Nigerian and U.S. patients were more sexually active than controls. Microcarcinoma (incidental, latent) of the prostate gland occurred with a frequency of 11.8% and at an age-adjusted incidence rate (world standard) of 40.6 per 1000 necropsies in the sampled U.S. black male population. The age-adjusted incidence rate (world standard) for microcarcinoma in the combined West African (Accra and Ibadan) series (36.7/1000) was almost equal to the rate (40.6/1000) in the Washington, D.C. series.

Retinol-binding proteins in human testis cytosol

In the cytosol fraction of human testes a specific binding protein for retinol has been isolated by sephadex column chromatography and by gradient centrifugation. The protein has a sedimentation coefficient of 2S, and its molecular weight is estimated by gel filtration to be approximately 16,000 daltons. Competitive binding studies with labeled retinol and 200-fold molar excess of unlabeled retinal, retinoic acid, retinyl palmitate and retinyl acetate indicate that the isolated protein is specific for retinol. Retinyl esters bind to the protein as effectively as retinol; however retinal binds to a lesser degree than retinol esters. In addition, a lower molecular weight protein of approximately 4,500 daltons was found in the cytosol that has comparatively lower affinity for retinol binding than the 16,000-dalton protein.

Evidence of higher ethynylestradiol blood levels in human hypertensive oral contraceptive users

These studies were designed to investigate the differences in blood plasma levels of ethynylestradiol (EE2) in women who developed hypertension while taking combined estrogen and progesterone oral contraceptives (OCs) and in normotensive OC users. Blood samples were collected in heparinized tubes 10 hours after OC ingestion, the plasma was separated, and EE2 was measured by radioimmunoassay. The results showed significantly higher plasma levels of EE2 in the hypertensive OC users as compared with the levels in normotensive OC users (P less than 0.01). In another study, blood samples from hypertensive and normotensive OC users were obtained for 3 consecutive days at fixed intervals following OC ingestion, and plasma levels of EE2 were measured. The results showed consistently higher EE2 blood levels during this 3-day period in the hypertensive subjects (P less than 0.01). It is postulated that the higher blood levels of EE2 in hypertensive OC users result from either decreased metabolism or excretion of synthetic estrogens.

Characterization of prostatic carcinoma among blacks: a continuation report

A clinical and pathologic comparison of carcinoma of the prostate in a high-risk US (Washington, DC) black population and in a low-risk Nigerian (Ibadan) black population is presented. Fifty-two percent of American patients were in clinical stages I and II, whereas only 10% of Nigerian patients were in the same stages. Testosterone and estradiol blood levels were significantly lower (P less than 0.05) in patients with carcinoma of the prostate from Ibadan compared with American black prostate cancer patients from Washington, DC. Age-standardized incidence rates (world standard) for 1000 autopsies for micro (incidental)-carcinoma were approximately equal in American and African black men. The incidence rate of invasive carcinoma was, however, even after adjustment for age, higher in American black men than in African men.

Vitamin A in bovine sperm acrosomes

Bull semen was collected artifically and vitamin A was determined in the intact spermatozoa, the acrosomes and the sperm tails. The results show that over 90% of the total vitamin A in the spermatozoa was present in the acrosomes and that the sperm tails were completely devoid of vitamin A. The concentration of vitamin A varied from 224 to 364 ng/10-9 spermatozoa.

Characterization of prostatic carcinoma among blacks: a preliminary report

This study was designed to compare United States (Washington, DC) black prostatic carcinoma patients (high-risk group) with Nigerian (Ibadan) black prostatic carcinoma patients (low-risk group). Although the material is meager, preliminary analyses suggest that carcinoma of the prostate is a common disease in both US black men (196 of 1000 autopsies) and in Nigerian black men (67 of 1000 autopsies). The tumor tends to be of a higher histologic grade (less well differentiated) and the carcinomatous foci are more numerous in the Nigerian patients. Fifty-three percent of US patients are in stages I and II when the disease is first discovered. Plasma testosterone, estrone, and estradiol concentrations did not differ significantly between US patients and controls. A statistically significant positive association is indicated between carcinoma of the prostate and the following epidemiologic variables: racial admixture, age of puberty, and age of first coitus. The median age of necropsy cases with carcinoma was 50.0 years in Nigeria and 68.3 years in the US.