Sputtered ZnO film on aluminium foils for flexible ultrasonic transducers.

Nanocrystalline ZnO films with both C-axis vertical grown and inclined angled grown were sputter-deposited onto aluminium foils (50 µm thick) and characterised for using as flexible ultrasonic transducers. As-deposited C-axis grown ZnO films were annealed at different temperatures up to 600 °C to enhance film crystallinity and reduce film stress. The C-axis grown ZnO film on the Al foil were bonded onto steel plates, and the pulse-echo tests verified a good performance (with dominant longitudinal waves) of the ultrasonic transducers made from both as-deposited and post-annealed films. Inclined angled ZnO films on the Al foil glued onto steel plates generated mixed shear and longitudinal waves in the pulse-echo test.

Annealing effect on the generation of dual mode acoustic waves in inclined ZnO films.

ZnO films with different inclined angles on steel substrates were sputter-deposited by changing the substrate tilt angle during deposition and then used to fabricate ZnO film ultrasonic transducers. The ultrasonic performance of those devices was characterized using a standard pulse-echo method. A dual mode wave with both longitudinal and shear wave components was detected from the ZnO device at 0° inclined angle. At a columnar inclined angle of 31°, longitudinal wave excitation was suppressed with a nearly pure shear wave detected. Post annealing of the ZnO film improved the crystallinity and decreased the film stress. The dispersion of the received echoes was observed when the grain sizes of ZnO films were increased after annealing. The frequency components of the waveforms were analyzed and identified using a short time Fourier transform. Post-annealing of the ZnO films changed the primary frequency and enhanced the propagation of the relative high-frequency acoustic wave.

Analysis of the proepicardium-epicardium transition during the malformation of the RXRalpha-/- epicardium.

The epicardium of the heart originates from a cluster of mesothelial-derived cells that develop beneath the sinus venosus in the embryonic day (E) 9.0-9.5 mouse. The subsequent proepicardium-epicardium transition that forms the epicardial layer of epithelial cells covering the myocardial surface is nearly complete by E10.0-E10.5 and results in a fully covered heart by E11.0. In this study, we show that an established model of congenital heart disease, the retinoid X receptor alpha knockout (RXRalpha-/-) embryo, displays a malformed epicardium. At E10.0-E10.5, the RXRalpha-/- has several large regions of myocardium that remain bare. Furthermore, by E11.5-E12.5, when a complete epithelial layer is formed in the mutant, large regions of the epicardium become distended from the underlying myocardium. Close examination of the E9.5 mutant revealed an elevated apoptosis level within the proepicardial cluster of mesothelial cells. Additionally, among the extracellular matrix proteins analyzed, expression of fibronectin was elevated in the RXRalpha-/- as assessed by immunostaining in paraffin-embedded sections and proepicardial explants. We propose that these events contribute to a developmental delay in the formation of the epicardium, which leads to an abnormal epicardium and ultimately contributes to the cardiac malformations seen in the RXRalpha-/-.

Elevated transforming growth factor beta2 enhances apoptosis and contributes to abnormal outflow tract and aortic sac development in retinoic X receptor alpha knockout embryos.

Septation of the single tubular embryonic outflow tract into two outlet segments in the heart requires the precise integration of proliferation, differentiation and apoptosis during remodeling. Lack of proper coordination between these processes would result in a variety of congenital cardiac defects such as those seen in the retinoid X receptor alpha knockout (Rxra(-/-)) mouse. Rxra(-/-) embryos exhibit lethality between embryonic day (E) 13.5 and 15.5 and harbor a variety of conotruncal and aortic sac defects making it an excellent system to investigate the molecular and morphogenic causes of these cardiac malformations. At E12.5, before the embryonic lethality, we found no qualitative difference between wild type and Rxra(-/-) proliferation (BrdU incorporation) in outflow tract cushion tissue but a significant increase in apoptosis as assessed by both TUNEL labeling in paraffin sections and caspase activity in trypsin-dispersed hearts. Additionally, E12.5 embryos demonstrated elevated levels of transforming growth factor beta2 (TGFbeta2) protein in multiple cell lineages in the heart. Using a whole-mouse-embryo culture system, wild-type E11.5 embryos treated with TGFbeta2 protein for 24 hours displayed enhanced apoptosis in both the sinistroventralconal cushion and dextrodorsalconal cushion in a manner analogous to that observed in the Rxra(-/-). TGFbeta2 protein treatment also led to malformations in both the outflow tract and aortic sac. Importantly, Rxra(-/-) embryos that were heterozygous for a null mutation in the Tgfb2 allele exhibited a partial restoration of the elevated apoptosis and of the malformations. This was evident at both E12.5 and E13.5. The data suggests that elevated levels of TGFbeta2 can (1) contribute to abnormal outflow tract morphogenesis by enhancing apoptosis in the endocardial cushions and (2) promote aortic sac malformations by interfering with the normal development of the aorticopulmonary septum.

Dilatation of biliary strictures through the afferent limb of a Roux-en-Y choledochojejunostomy in patients with sclerosing cholangitis.

Repeated dilatation of biliary strictures in patients with sclerosing cholangitis through a subcutaneously placed afferent limb of a choledochojejunostomy is technically feasible and safe. This study is a prospective 15-year evaluation of 36 patients treated by repeat dilatation through this jejunal limb. There was one operative death and one major complication of dilatation. The 5-year survival of all patients was 74%. If patients with cirrhosis or unproven cholangiocarcinoma at the time of operation are not included, the 5-year survival is 86%. The 15-year survival of all patients was 30%; it was 64% if those with cirrhosis and unproven cholangiocarcinoma at the time of operation are not included. Six patients are presently alive with an average survival of 159 months. The study suggests that a combination of repeated dilatations combined with transplantation is the approach of choice in selected patients.

A subcutaneous or subfascial jejunostomy is beneficial in the surgical management of extrahepatic bile duct cancers.

BACKGROUND: Extrahepatic bile duct cancers are rare tumors with a dismal prognosis. Even after a resection, obstructive cholestasis and other biliary complications are the rule. To facilitate retrograde access to the biliary tree for treatment of such biliary complications, a modified Roux-en-Y hepaticojejunostomy is constructed such that the afferent limb is brought up as a subcutaneous or subfascial jejunostomy (SJ). The safety and utility of construction of an SJ was evaluated in patients with extrahepatic cholangiocarcinoma. METHODS: From 1985 to 1997, 24 patients with extrahepatic bile duct cancers received an SJ as part of their management. Demographic data, operative data, tumor characteristics, and postoperative courses were retrospectively reviewed. All but 3 patients were followed to the time of death. RESULTS: The average age of the patients was 62 +/- 9 years. The tumor was resected in 17 patients. Major complications occurred in 5 patients (21%). There was 1 operative death (4%). None of the complications could be attributed to construction of the SJ, although 1 patient had a soft tissue infection at the site of the percutaneous access of the SJ. Frequent dilatations of biliary strictures were required in 5 patients, and 1 patient eventually required insertion of an internal biliary stent. These procedures could all be accomplished through the SJ. CONCLUSIONS: The SJ is a technically simple and safe addition to the management of resectable and unresectable extrahepatic bile duct cancers, particularly proximal lesions. The procedure facilitates brachytherapy if indicated, and it allows convenient management of postoperative biliary complications, including recurrent strictures.

Radical resection of periampullary tumors in the elderly: evaluation of long-term results.

Increasingly, patients of advanced age are coming for evaluation of periampullary tumors. Although several studies have demonstrated the safety of resecting periampullary tumors in older patients, few long-term survival data have been reported. Between 1983 and 1992 various periampullary masses were resected in 70 patients over age 65 (range 65-87 years). Total pancreatectomy was performed in 11 patients, and 59 patients underwent pancreaticoduodenectomy. The mean duration of hospitalization was 17 +/- 15 days. Major complications occurred in 27 patients (39%), and operative mortality rate was 8.5%. Overall median survival was 24 months; and 5-year survival was 25%. Perioperative outcome was compared in patients aged 65 to 74 years and in patients > or =75 years old. The older age group required longer periods in the surgical intensive care unit postoperatively, but the long-term survival was similar in the two age groups. Radical resection with the intent to cure periampullary tumors is safe in selected patients of advanced age, and long-term survival is in the range of expected survival for younger patients with the same tumors.

Percutaneous dilatation of biliary strictures through the afferent limb of a modified Roux-en-Y choledochojejunostomy or hepaticojejunostomy.

BACKGROUND: This report is a 13-year prospective evaluation of percutaneous balloon dilatation of benign biliary strictures through the subcutaneous or subfascially positioned afferent limb of a choledocho or hepaticojejunostomy in 30 patients. DATA SOURCE: Twenty-seven strictures developed after a common duct injury sustained at the time of cholecystectomy, two after hepatectomy reconstruction for trauma and one following a gastrectomy. Twelve injuries (40%) were recognized at operation. Of the 18 patients where the injury was unrecognized at the time of operation, 8 had not been reoperated at the time of referral, 7 had late repairs by the referring physician, and 3 had late repairs at our institution. The follow-up is 1 to 13 years. RESULTS: There has been 1 late death and 6 patients are lost alive. The jejunal-limb was accessed 50 times with two minor and no major complications. There have been two parajejunal hernia repairs, but there have not been any reoperations for recurrent biliary strictures. CONCLUSIONS: Benign biliary strictures can be effectively managed by repeat balloon dilatations thru the afferent limb of a choledocho or hepaticojejunostomy, thus eliminating the need for repeat surgical interventions.

The metabolism of 3-phenoxybenzoic acid-containing xenobiotic triacylglycerols in vitro by pancreatic, hormone-sensitive and lipoprotein lipases.

Two model substrates, rac-1-(3-phenoxy-[ring-14C]benzoyl)-2,3-dipalmitoyl glycerol (1(3PBA)DPG) and sn-2-(3-phenoxy-[ring-14C]benzoyl)-1,3-dipalmitoyl glycerol (2(3PBA)DPG), were compared with tri[1-14C]palmitoylglycerol or tri[9,10(n)-3H]oleoylglycerol as substrates for pancreatic lipase, lipoprotein lipase, and hormone-sensitive lipase. The loss of 3PBA from the sn-2 position was always low because of the positional specificity of the lipases. The loss of 3PBA from the rac-1 position was similarly low with hormone-sensitive lipase (about 7% of the loss of oleate), but higher with pancreatic lipase (about 35% that of oleate) and lipoprotein lipase (about 23% that of oleate). With one exception, more than 50% and up to 80% of the 14C-3PBA was still in the form of a diacylglycerol after incubation with a lipase, whereas free acid or monoacylglycerol forms would have been expected. Lipoprotein lipase acting on 1-(14C-3PBA)DPG produced nearly 70% of its product as nonesterified 3PBA and only 25% as the diacylglycerol. The results suggest that 3PBA-containing xenobiotic triacylglycerols, and the 3PBA-glycerol ester bond in particular, are poorer substrates for lipases than are their natural counterparts, with the result that high proportions of partially digested xenobiotic acylglycerols are produced. The three lipases performed differently with the xenobiotic substrates; this could have consequences for the relative rates of storage and clearance of the xenobiotic triacylglycerols from the body.

The metabolism of the xenobiotic triacylglycerols, rac-1- and sn-2- (3-phenoxybenzoyl)-dipalmitoylglycerol, following intravenous administration to the rat.

The metabolism of 3-phenoxybenzoic acid (3PBA) in the form of triacylglycerol conjugates was compared with that of non-esterified 3PBA. Three radiolabeled triacylglycerols (rac-1-(3-phenoxy-[ring-14C]-benzoyl)-2,3-dipalmitoylglycerol (1(3PBA)DPG), sn-2-(3-phenoxy-[ring-14C]benzoyl)-1,3-dipalmitoylglycerol (2(3PBA)DPG) and the "natural" tri-[1-14C]oleoylglycerol) were incorporated into rat VLDL. Nonesterified 3PBA was prepared in rat serum albumin solution. Each preparation was administered i.v. to rats and serial blood samples were taken during the subsequent 6 hr. Urine and faeces were collected and tissue residues determined at 6 hr and 48 hr after administration. Biphasic elimination of 3PBA was observed with half-lives of 18 min and 2 hr. The triacylglycerols showed a rapid first phase and a longer second phase half-life: trioleoylglycerol 26 hr, 1(3PBA)DPG 7.6 hr and 2(3PBA)DPG 17.3 hr. The majority (63-76%) of 3PBA (whether esterified or not) was eliminated within 24 hr in urine, which contained similar profiles of metabolites. The triacylglycerols gave rise to higher tissue residues than did non-esterified 3PBA, particularly in adipose tissue which alone was not significantly depleted of radioactivity between 6 and 48 hr. The results accord with the rapid association of the VLDL-(3PBA)DPG complexes with lipoprotein lipase of the capillary epithelium, followed by hydrolysis to 3PBA, metabolism and elimination but with a proportion being redistributed into adipose tissue, re-esterified and then eliminated relatively slowly.

A technique for prolonged arterial infusions of fibrinolytic agents in the immediate postoperative period through a cutaneous venostomy.

Prolonged use of fibrinolytic agents post thrombectomy is limited by present techniques that require arterial puncture and indwelling arterial catheters. This limitation can be avoided by attaching a short segment of saphenous vein to the arteriotomy used for the thrombectomy and bringing this out to the skin as a "venostomy"; thus providing ready access to the vascular tree for arteriography, prolonged infusion of thrombolytic agents, or selective catheter placement. In delayed thrombectomies (Categories 2 & 3 as described by the Ad Hoc Committee on Reporting Standards, J Vasc Surg 1986;4:80-94), extending the use of these agents may represent the only hope for limb salvage.

Trends in resident experience in open and laparoscopic cholecystectomy.

Laparoscopic cholecystectomy (LC) has replaced open cholecystectomy (OC) as the most common operation for gallbladder disease. Our goal was to determine the effect of this phenomenon on resident training in biliary surgery. The numbers of all cholecystectomies (ACs), OCs, LCs, and advanced procedures (common bile duct exploration and choledochoscopy, (CBDE) performed by residents during academic years 1989 to 1994 were examined. Trends for the residency as a whole and for each cohort of residents completing the program were studied. The number of LCs performed by the residency as a whole per academic year over the 1989 to 1994 period has increased, whereas the number of OCs decreased. The net effect of these trends was an increase in the number of ACs. Although the percentage of LCs performed by postgraduate year 1, 2, and 3 residents (juniors) increased over the study period, the proportion of OCs and ACs performed by this group decreased. For each cohort of residents completing training in the years 1989 through 1994, the number of ACs and LCs performed increased, whereas the number of OCs decreased. Experience in CBDE for the residency as a whole and for the cohort was stable. In conclusion, experience in ACs and LCs has increased, and experience in OCs has decreased. Also, experience in biliary surgery has shifted to the senior level.

Neonatal predictors of infection status and early death among 332 infants at risk of HIV-1 infection monitored prospectively from birth. New York City Perinatal HIV Transmission Collaborative Study Group.

BACKGROUND AND METHODS: Differences in newborn outcome measures for human immunodeficiency virus (HIV)-1-infected and HIV-1-exposed but uninfected infants have been found in several studies, but not in others. Eighty-four infected and 248 uninfected children born to HIV-1-seropositive mothers followed prospectively in a multicenter, perinatal HIV-1 transmission cohort study were compared for differences in maternal demographics, health status, and newborn outcome measures, including delivery complications, physical examination findings, neonatal complications, and laboratory results. RESULTS: Mothers of HIV-1-infected infants were more likely than those of uninfected infants to have acquired immunodeficiency syndrome (AIDS) diagnosed through 2 weeks postpartum (21% vs 11%, P = .04); the transmission rate for the 38 women with AIDs was 37% compared with 22% for the 245 women without AIDS. Two of 27 (7%) women receiving zidovudine during pregnancy had infected infants compared with 73 (27%) of 275 women who did not receive zidovudine (P = .033). Mean gestational age was significantly lower among HIV-1-infected (37 weeks) than among uninfected infants (38 weeks; P < .001). Infected infants had significantly higher rates of prematurity (gestational age less than 37 weeks) (33% vs 19%, P = .01) and extreme prematurity (gestational age less than 34 weeks) (18% vs 6%, P = .001) than uninfected infants. Infection was associated with lower birth weight (2533 g vs 2862 g, P < .001) and smaller head circumference (32.0 cm vs 33.1 cm, P = .001). HIV-1-infected infants were significantly more likely to be small for gestational age (26% vs 16%, P = .04) and low birth weight (less than 2500 g) (45% vs 29%, P = .006) than infants who were uninfected. Twenty-two (26%) HIV-1-infected children died during a median follow-up of 27.6 months (range 1.9 to 98.3 months). Prematurity was predictive of survival: by Kaplan-Meier, an estimated 55% (95% confidence interval, 31% to 72%) of preterm infected children survived to 24 months compared with 84% (95% confidence interval, 70% to 92%) of full-term infected children (P = .005). CONCLUSION: Infants born to women with AIDS are at higher risk for HIV-1 infection than are infants born to HIV-1-infected women with AIDS not yet diagnosed. Women receiving zidovudine appear less likely to transmit HIV-1 to their infants. Significantly higher rates of prematurity and intrauterine growth retardation were found among HIV-1-infected infants than among those in the uninfected, HIV-1-exposed control group. Prematurity was associated with shortened survival in HIV-1-infected infants. Measures of intrauterine growth and gestation appear to be important predictors of HIV-1 infection status for seropositive infants and of prognosis for the infected infant.

Balloon dilatation through the subcutaneously placed afferent limb of a hepaticojejunostomy in patients with resected Klatskin tumors.

It is generally conceded that palliation for proximal bile duct tumors (Klatskin) is exceptional if obstruction and the resultant infections can be prevented. Our experience with balloon dilatations thru the subcutaneously placed afferent limb of a choledocho or hepatico jejunostomy in patients with benign strictures suggests that this approach will be effective in patients with malignancies and thus provide long-term control of the obstruction without the need for external tubes. This is a report on one patient who, following a resected Klatskin tumor with positive margins, was treated with transhepatic internal external stents and was converted to a subcutaneous limb following numerous bouts of cholangitis. A schedule for repeat dilatations thru the jejunal limb was established. The patient has remained afebrile with a normal bilirubin and a moderately elevated alkaline phosphatase. Recurrent tumors or postirradiation strictures in patients with resected Klatskin tumors can be effectively controlled by repeated balloon dilatation without the need for external stents.

Maternal predictors of perinatal human immunodeficiency virus transmission. The New York City Perinatal HIV Transmission Collaborative Study Group.

This analysis sought to identify characteristics of pregnant human immunodeficiency virus type 1 (HIV-1)-infected women that predict mother-to-child HIV-1 transmission. Pregnant and immediately postpartum women at risk for HIV were enrolled at obstetric and pediatric care settings in New York City from 1986 to 1992. Demographic and behavioral characteristics, clinical illness, T lymphocyte subsets, immunoglobulin concentration and syphilis serology were collected on the women. Infants were followed to determine HIV infection classification according to Centers for Disease Control and Prevention criteria for HIV-1 in children. Transmission rates were calculated for women who gave birth more than 15 months before the analysis. Of 172 HIV-1-infected women with known outcome 49 (28%) had infected infants. The transmission rate (TR) was significantly higher among women with < 280 CD4+ cells/microliters (lowest CD4+ quartile) than with CD4+ counts > 280 (48% vs. 22%; P = 0.004; odds ratio, 3.4; 95% confidence interval (1.5, 7.8)); a similar trend was seen by CD4+% quartile. No difference in TR was seen comparing women by CD8+ count quartile but marginally higher TR was seen among women with CD8+% > or = 51% than with CD8+% < 51% (TR = 41% vs. 24%; P = 0.076; odds ratio, 2.2; confidence interval (1.0, 5.1)). The highest TR, 62% was seen in women with both CD8+ count above the median and CD4+ count in the lowest quartile. No significant difference in TR was seen between women with and without HIV-related illness, although the TR was 53% among women hospitalized in the previous year for pneumonia compared with 25% in others (P = 0.03). TR was somewhat lower in women who delivered by cesarean section than vaginally (entire cohort: 18% vs. 32%, P = 0.11; prenatal enrollees only, 17% vs. 38%, P = 0.045). No factor or combination of factors was both highly sensitive and specific for predicting mother-to-child HIV transmission. A possible relationship between transmission and mode of delivery deserves further investigation.

Pulseless (Takayasu) disease with ophthalmic manifestations.

Pulseless disease (PD) is a rare disorder in which inflammation of the aorta and its major branches leads to stenosis or occlusion of these arteries. It mainly affects young Oriental women, who suffer chronic ischemic injury to tissues of the brain, orbits, upper limbs, myocardium, and kidneys. The ophthalmologic features of pulseless disease tend to be late manifestations, and can include ischemia of the retina, choroid, and anterior segment. The inflammatory process may be reversed in early stages with systemic corticosteroids, but, more frequently, significant arterial stenosis necessitates arterial bypass surgery. A 59-year-old Caucasian woman with stenosis of all four major cervical arteries presented with recurrent blurred vision, syncope, mental obtundation, and a remarkable funduscopic appearance due to bilateral orbital hypoperfusion. Her acute symptoms improved slightly on high-dose systemic corticosteroids, and then resolved completely following arterial bypass surgery.

Human immunodeficiency virus 1-specific IgA capture enzyme immunoassay for early diagnosis of human immunodeficiency virus 1 infection in infants. NYC Perinatal HIV Transmission Study Group.

A simplified human immunodeficiency virus 1 (HIV-1)-specific IgA capture enzyme immunoassay (IgA-CEIA) was evaluated and compared with IgA-Western blot assay for early diagnosis of HIV-1 infection in infants born to seropositive women. A total of 232 coded sera collected prospectively from 70 infants were tested. All 25 sera from 10 HIV-1-negative infants born to seronegative mothers (negative controls) were negative by both assays. All 111 sera from 37 seroreverting, uninfected infants were negative by IgA-CEIA (specificity, 100%), whereas 110 of 111 sera were negative by IgA-Western blot assay (specificity, > 99%). Overall IgA-CEIA detected HIV-IgA in 20 (87%) of 23 infected infants, and IgA-Western blot assay detected HIV-IgA in 21 (91.3%) of 23 infants; specimen-wise agreement between the 2 assays was > 80%. Analysis of results by age group indicated that after 2 months of age both assays were equivalent with sensitivity ranging from 60 to 80%. Quantitative data provided by IgA-CEIA suggests that the bulk of HIV-1 IgA synthesis in most HIV-1-infected infants occurs after 2 months of age.

Dynamics of maternal IgG antibody decay and HIV-specific antibody synthesis in infants born to seropositive mothers. The NYC Perinatal HIV Transmission Study Group.

We have used a human immunodeficiency virus type 1 (HIV-1)-specific IgG-Fc capture enzyme immunoassay (IgG-CEIA) to elucidate the dynamics of HIV-1 maternal antibody decay and de novo synthesis of HIV-1 antibodies in infants. Two hundred and thirty-nine serum specimens from 77 infants were analyzed by the IgG-CEIA and by two different conventional EIAs. With the IgG-CEIA, IgG was captured by an anti-human IgG monoclonal antibody (3C8) that reacts with all subclasses and was detected by recombinant HIV-1 envelope protein (CBre3)-peroxidase conjugate. Unlike the conventional EIAs, the IgG-CEIA showed a rapid decay of HIV-1-specific antibody in uninfected infants, with decline to background levels by 6 months (T1/2 [half-life] = 28-30 days). All 69 specimens collected from 39 uninfected infants between 6 and 15 months of age were negative by IgG-CEIA. However, HIV-1 antibodies remained high in infected infants; 20/22 infants (90.9%) with specimens between the ages of 6 to 23 months were positive by IgG-CEIA. Subtracting mean IgG-CEIA optical density values of seroreverting infants from those of HIV-1-infected infants in corresponding age groups provided a model for seroconversion in infected infants, with detectable IgG antibody synthesis starting about 3 months after birth. The IgG-CEIA may be a simple and important tool for early diagnosis of HIV-1 infection in infants at 6 months of age.