Injection therapy for stress incontinence in women

Periurethral bulking agents have been used to treat intrinsic sphincter deficiency for decades. Currently available agents include polytetrafluoroethylene, glutaraldehyde cross-linked collagen, autologous fat and silicone microimplants. Polytetrafluoroethylene has never been approved by the United States Food and Drug Administration for periurethral injection because of the risk of particle migration. Early results have reported subjective cure rates of up to 95% with collagen injections. However, collagen may cause allergic reactions and long-term results are still awaited. Periurethral fat injection has a reported success rate ranging from 23% to 65%. It is simple and avoids the use of foreign materials, but the main disadvantage relates to the variability of resorption and connective tissue replacement. Silicone microimplants need further study to evaluate their efficacy and safety. The best material has not yet been defined. Long-term studies are still necessary to define the optimal injectable agent.

Quantitative magnetic resonance imaging in experimental hypercapnia: improvement in the relation between changes in brain R2 and the oxygen saturation of venous blood after correction for changes in cerebral blood volume

Acute hypercapnia simultaneously induces increases in regional cerebral blood volume (rCBV) and the oxygen saturation of cerebral venous blood (Yv). Changes in both physiologic parameters may influence the changes in R2 (deltaR2) that can be measured in the brain with gradient echo magnetic resonance imaging. The authors examined the effect of incorporating independent measurements of the change in rCBV (deltarCBV) on the fidelity of the relation between deltaR2 and deltaYv in the setting of experimental hypercapnia. A two-dimensional T2-weighted gradient echo sequence was used to measure deltaR2 in the brain parenchyma of anesthetized rats in response to hypercapnia with respect to the control state. In parallel, estimates of rCBV were obtained using a three-dimensional steady-state approach in conjunction with a paramagnetic contrast agent during both control and hypercapnic states so that a deltarCBV could be calculated. Regional CBV values of 2.96 +/- 0.82% and 5.74 +/- 1.21% were obtained during the control and hypercapnic states, respectively, and linear relations between rCBV and CO2 tension in both arterial (r = 0.80) and jugular venous (r = 0.76) blood samples were obtained. When correlating deltaR2 directly with deltaYv, no clear relation was apparent, but a strong linear relation (r = 0.76) was observed when correction for deltarCBV was incorporated into the data analysis. These results are consistent with the current understanding of the mechanisms of blood oxygen level-dependent (BOLD) contrast and underscore the potential importance of taking into account deltarCBV when quantitative estimates of deltaYv from the "BOLD effect" are intended.

Post-functional endoscopic sinus surgery methicillin-resistant Staphylococcus aureus sinusitis

Methicillin-resistant Staphylococcus aureus (MRSA) is a highly virulent bacterium that is difficult to eradicate. It has become a common nosocomial pathogen, but it also causes sporadic infections in some outpatients. Among 358 chronic sinusitis patients who received functional endoscopic sinus surgery (FESS) for treatment between July 1995 and June 1997 in our department, 18 were infected postoperatively by MRSA by the end of August 1997. One patient was excluded because she received another nasal surgery, partial turbinectomy, and submucous resection of the nasal septum, after FESS. Most of 17 MRSA infected patients presented themselves with mucopurulent nasal discharge and/or nasal crust. The treatment was generally difficult because MRSAs were resistant to multiple antibiotics. When quinolone antibiotics were used to treat most patients, the improvement rate was 76.5%. We conclude that MRSA infections in post-FESS patients might affect the outcome of FESS.

Pyrithione, a zinc ionophore, inhibits NF-kappaB activation

Pyrrolidine dithiocarbamate (PDTC) suppresses NF-kappaB activity and exhibits cytotoxic effects in bovine cerebral endothelial cells (BCECs), and we have previously reported that these PDTC effects were accompanied by an increase in intracellular zinc levels. To further explore the role of zinc in the modulation of NF-kappaB activation, we studied the effect of pyrithione, a zinc ionophore, on NF-kappaB activation in BCECs. Pyrithione inhibited NF-kappaB activity in a time- and dose-dependent manner. Ca-EDTA, but not Zn-EDTA, prevented pyrithione inhibition of NF-kappaB activity. Pyrithione increased the intracellular zinc level within 15 min. This effect was also abolished by Ca-EDTA, but not by Zn-EDTA. The potency of pyrithione on NF-kappaB inhibition and zinc influx was approximately one order of magnitude more potent than PDTC. These findings establish the regulatory role of intracellular zinc levels on NF-kappaB activity in BCECs.

Berberine-induced apoptosis of human leukemia HL-60 cells is associated with down-regulation of nucleophosmin/B23 and telomerase activity

The steady-state level of nucleophosmin/B23 mRNA decreased during berberine-induced (25 microg/ml, 24 to 96 hr) apoptosis of human leukemia HL-60 cells. A decline in telomerase activity was also observed in HL-60 cells treated with berberine. A stable clone of nucleophosmin/B23 overexpressed in HL-60 cells was selected and found to be less responsive to berberine-induced apoptosis. About 35% to 63% of control vector-transfected cells (pCR3) exhibited morphological characteristics of apoptosis, while about 8% to 45% of nucleophosmin/B23-over-expressed cells (pCR3-B23) became apoptotic after incubation with 15 microg/ml berberine for 48 to 96 hr. DNA extracted from pCR3 cells contained more fragmented DNA than pCR3-B23 cells during treatment with 15 microg/ml berberine for 24 to 48 hr. Our results indicate that berberine-induced apoptosis is associated with down-regulation of nucleophosmin/B23 and telomerase activity. We also suggest that nucleophosmin/B23 may play an important role in the control of the cellular response to apoptosis induction.

Evidence that several conserved histidine residues are required for hydrolytic activity of human paraoxonase/arylesterase

Recent evidence has been acquired that implicates an important role for several histidine residues in the hydrolytic mechanisms of human paraoxonase/arylesterase (PON1). Following titration with diethylpyrocarbonate (DEPC), both human serum and recombinant human type Q PON1 were inhibited in respect to their hydrolytic activity in a dose-responsive manner. Human PON1 treated with varying concentrations lost hydrolytic activity, and with each histidine modified, there was an exponential drop in hydrolytic activity. The reaction was followed spectrophotometrically at 244 nm. Recombinant wild-type and C283A PON1 enzymes inhibited with DEPC and subsequently treated with hydroxylamine had partial restoration of activity. The C283A mutant lacks a free sulfhydryl group, indicating that its inactivation is due to histidine specific modification. The dose response and time course of inactivation as well as the extent of reactivation by hydroxylamine were similar for both the wild-type and mutant recombinant enzymes. Mutants of PON1 containing an asparagine substituted for each of several conserved histidine residues lost hydrolytic activity for each single substitution. The mutants of PON1 constructed and assayed for arylesterase activity were H114N, H133N, and H284N. Each single aminoacid substitution rendered the enzyme catalytically inactive. These two pieces of evidence implicate an important role for several histidine residues in the hydrolytic mechanism of PON1. Although it is unusual for a calcium dependent enzyme to require histidines for its catalytic activity, acquired data suggest such a circumstance.

Properties of the retained N-terminal hydrophobic leader sequence in human serum paraoxonase/arylesterase

Human serum paraoxonase/arylesterase (PON1) is HDL-associated and appears to protect low density lipoproteins (LDL) from oxidation. Mature PON1 retains its N-terminal hydrophobic signal sequence, which may be needed for binding to HDL. By site-directed mutagenesis, we created a mutant PON1 (A19A20) with a cleavable N-terminus to determine if this peptide mediated binding to lipoproteins. As a model system, we studied binding of mutant and wild type PON1s to lipoproteins in fetal bovine serum-containing expression medium and found that the wild type recombinant enzyme associated with lipoproteins whereas the A19A20 mutant did not. These results show that the N-terminus is required for binding to either apolipoproteins or phospholipids. Furthermore, we showed that wild type enzyme can bind to phospholipids directly without apolipoproteins. To determine if lipid binding is a requirement for PON1's protection against LDL oxidation, we used a copper ion-induced oxidation system and found that the wild type enzyme and A19A20 mutant showed similar reductions in both peroxide and aldehyde formation. We conclude that PON1 depends upon its N-terminal hydrophobic peptide for its association with serum lipoproteins.

Zinc is required in pyrrolidine dithiocarbamate inhibition of NF-kappaB activation

Pyrrolidine dithiocarbamate (PDTC) is a potent inhibitor of nuclear factor kappa B (NF-kappaB) activation. PDTC inhibited basal NF-kappaB activity of endothelial cells. PDTC, however, failed to inhibit basal NF-kappaB activity after withdrawal of serum in the media, and the inhibitory effect of PDTC could be restored by addition of zinc. When various preparations of metal ion-EDTA were tested with PDTC in serum-containing media, only Zn-EDTA failed to block the inhibitory effect of PDTC. The dependence on zinc was also noted in PDTC inhibition of NF-kappaB stimulated by TNF alpha. These facts suggest that zinc is required for PDTC inhibition of NF-kappaB activation.

Predictors of acute hospital costs for treatment of ischemic stroke in an academic center

BACKGROUND AND PURPOSE

We sought to determine predictors of acute hospital costs in patients presenting with acute ischemic stroke to an academic center using a stroke management team to coordinate care.

METHODS

Demographic and clinical data were prospectively collected on 191 patients consecutively admitted with acute ischemic stroke. Patients were classified by insurance status, premorbid modified Rankin scale, stroke location, stroke severity (National Institutes of Health Stroke Scale score), and presence of comorbidities. Detailed hospital charge data were converted to cost by application of department-specific cost-to-charge ratios. Physician's fees were not included. A stepwise multiple regression analysis was computed to determine the predictors of total hospital cost.

RESULTS

Median length of stay was 6 days (range, 1 to 63 days), and mortality was 3%. Median hospital cost per discharge was $4408 (range, $1199 to $59 799). Fifty percent of costs were for room charges, 19% for stroke evaluation, 21% for medical management, and 7% for acute rehabilitation therapies. Sixteen percent were admitted to an intensive care unit. Length of stay accounted for 43% of the variance in total cost. Other independent predictors of cost included stroke severity, heparin treatment, atrial fibrillation, male sex, ischemic cardiac disease, and premorbid functional status.

CONCLUSIONS

We conclude that the major predictors of acute hospital costs of stroke in this environment are length of stay, stroke severity, cardiac disease, male sex, and use of heparin. Room charges accounted for the majority of costs, and attempts to reduce the cost of stroke evaluation would be of marginal value. Efforts to reduce acute costs should be monitored for potential cost shifting or a negative impact on quality of care.

High rate of clinical complete response to weekly outpatient neoadjuvant chemotherapy in oral carcinoma patients using a new regimen of cisplatin, 5-fluorouracil, and bleomycin alternating with methotrexate and epirubicin

BACKGROUND

A Phase II trial was initiated to evaluate the response to and toxicity of a new regimen of weekly outpatient neoadjuvant chemotherapy in patients with oral carcinoma.

METHODS

Patients with previously untreated squamous cell carcinoma of the oral cavity were eligible for this trial. The neoadjuvant chemotherapy was comprised of cisplatin, 25 mg/m2, 5-fluorouracil, 1000 mg/m2, and bleomycin, 10 mg/m2, mixed in normal saline as a 24-hour intravenous (i.v.) infusion, alternating with methotrexate, 30 mg/m2, and epirubicin, 30 mg/m2, as an i.v. bolus (PFB/ME) on a weekly schedule for 8-12 weeks. In patients with American Joint Committee on Cancer Stage IV disease who completed neoadjuvant chemotherapy, surgery was preferred to radiotherapy, unless patients refused surgery.

RESULTS

A total of 40 patients (82.5% with Stage IV disease) with previously untreated oral carcinoma were enrolled. The median size of the primary tumor was 7 cm (range, 3-13 cm). Fifty percent of patients had tumor penetrating through the oral mucosa to the cheek skin and 62.5% had bony destruction. Detectable cervical lymph nodes were noted in 77.5% of patients. After neoadjuvant weekly chemotherapy, 22 patients (55%) showed complete response (CR) and 15 patients (37.5%) showed partial response, for an overall response rate of 92.5%. World Health Organization Grade 3/4 toxicity included mucositis (7.5%), leukopenia (25%), anemia (10%), and thrombocytopenia (2.5%). Eleven of 33 patients with Stage IV disease underwent surgery, and pathologic CR (2 patients) or microscopic residual tumor (4 patients) was noted (54.5%).

CONCLUSIONS

The results of the current study indicate that a weekly PFB/ME neoadjuvant chemotherapy regimen is highly effective for the treatment of patients with oral carcinoma. In addition, this regimen has low toxicity. The authors believe that implementation of this regimen into a multimodality therapy protocol deserves further study.

Pyrrolidine dithiocarbamate induces bovine cerebral endothelial cell death by increasing the intracellular zinc level

The antioxidant and metal-chelating effects of pyrrolidine dithiocarbamate (PDTC) have been extensively studied. PDTC prevents cell death induced by various insults. However, PDTC itself may cause cell death in selected experimental paradigms. PDTC induced bovine cerebral endothelial cell death. However, in serum-depleted medium, PDTC did not affect the cell viability, suggesting that certain factors in serum may mediate the cytotoxic effect of PDTC. The metal chelators bathocuproine disulfonic acid, o-phenanthroline, bathophenanthroline disulfonic acid, and N,N,N',N'-tetrakis(2-pyridyl-methyl)ethylenediamine (TPEN) prevented the cell death induced by PDTC. In a serum-deprived condition, addition of exogenous metals, copper or zinc, restored the cytotoxic effect of PDTC. These data indicate that metals such as copper or zinc in serum may mediate the cytotoxic effect of PDTC. The potency of zinc for PDTC-induced endothelial cell death was greater than that of copper. Zn-EDTA did not block PDTC-induced cell death, whereas Ca-EDTA and Cu-EDTA were able to prevent this PDTC effect. PDTC increased the intracellular fluorescence of the zinc probe dye N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide, which was quenched by TPEN or various EDTA preparations but not by Zn-EDTA. Results suggest that an increase in intracellular zinc concentration is required in PDTC-induced cerebral endothelial cell death.

Sex-specific expression of N-methyl D-aspartate receptor (NMDAR) in the preoptic area of neonatal rats

The relationship between the N-methyl-D-aspartate receptor (NMDAR) and the sex-specific neurotoxicity of L-glutamate on the preoptic area (POA) of neonatal rats was studied. The NMDAR were semiquantified by western blot analysis. The kinetic change of intracellular calcium and lactate dehydrogenase (LDH) efflux were monitored as rapid and delayed toxic signals, respectively. The results showed that: (1) the NMDAR expression in POA of male rat is higher than that of females; (2) the L-glutamate (500 microM) induced a more significant elevation of intracellular calcium in neuron derived from male rat than that from female; (3) after glutamate-treatment, the LDH efflux in neuronal culture of male rat is higher than that of females. These results suggest that the quantitative difference in NMDAR between male and female rats may contribute to the sex-specific neurotoxicity of L-glutamate on the POA of neonatal rats.

Allogeneic stem cell transplantation for patients with high-risk myelodysplastic syndrome

Allogeneic stem cell transplantation (allo-SCT) is the only treatment with curative potential for patients with myelodysplastic syndrome (MDS). From June 1986 to April 1997, we treated 12 patients with primary MDS (5 men, 7 women, median age, 36.5 years) by allo-SCT. All patients had one or more of the following poor prognostic factors: intermediate-2 or high-risk categories according to the International Prognostic Scoring System; disease progression during follow-up; heavy transfusion requirements and recurrent infections. The median duration from diagnosis of MDS to allo-SCT was 6 months. The preconditioning regimen included total body irradiation combined with either high-dose cytarabine (n = 6), high-dose cyclophosphamide (n = 4), or other regimens (n = 2). Ten patients received bone marrow transplantations and two patients received peripheral blood stem cell transplantations. Prophylaxis for graft-versus-host disease (GVHD) consisted of standard cyclosporin and short-course methotrexate. Acute GVHD of grade 2 or above occurred in 10 patients, while chronic GVHD occurred in seven of the nine patients who survived longer than 6 months after allo-SCT. With a median follow-up of 50 months, all nine patients with human leukocyte antigen (HLA)-matched sibling donors survived. One patient had a relapse 6 months after transplantation and achieved complete remission again with low-dose cytarabine therapy. The three patients receiving allo-SCT from unrelated or HLA-mismatched donors died of grade 3 to 4 acute GVHD and infection within 5 months after transplantation. The estimated disease-free survival at 4 years was 67% (95% confidence interval, 40-93%), and the overall survival was 75% (95% confidence interval, 50-99%). Our data suggest that allo-SCT should be considered early in the clinical course for young MDS patients with a poor prognosis and a matched sibling donor.

Endoscopic sinus surgery for rhinocerebral mucormycosis

Rhinocerebral mucormycosis is a fulminant, often fatal, disease. Aggressive surgical debridement has been considered an important part of treatment. Traditionally, an external or transantral approach has been the classic method. Recently, endoscopic sinus surgery (ESS) has been tried on several occasions to reach the goal of radical resection. Since 1991, ESS has been used to treat 9 rhinocerebral mucormycosis patients in our department. Among them, ESS was the only surgical procedure in six patients. The other three patients were treated by ESS combined with a transantral procedure. As a result, eight patients (88.9%) have survived the disease. One patient died 5 days after ESS because of an internal carotid artery occlusion. We conclude that ESS can be used to treat rhinocerebral mucormycosis alone or in combination with the traditional surgical procedures. It has the advantage of less operative morbidity and greater operative accuracy.

Suppression of postischemic hippocampal nerve growth factor expression by a c-fos antisense oligodeoxynucleotide

We examined the uptake and distribution of an antisense phosphorothioated oligodeoxynucleotide (s-ODN) to c-fos, rncfosr115, infused into the left cerebral ventricle of male Long-Evans rats and the effect of this s-ODN on subsequent Fos, NGF, neurotrophin-3 (NT-3), and actin expression. To establish the uptake and turnover of s-ODN in the brain, we studied the copurification of the immunoreactivity of biotin with biotinylated s-ODN that was recovered from different regions of the brain. A time-dependent diffusion and the localization of s-ODN were further demonstrated by labeling the 3'-OH terminus of s-ODN in situ with digoxigenin-dUTP using terminal transferase and detection using anti-digoxigenin IgG-FITC. Cellular uptake of the s-ODN was evident in both the hippocampal and cortical regions, consistent with a gradient originating at the ventricular surface. Degradation of the s-ODN was observed beginning 48 hr after delivery. The effectiveness of c-fos antisense s-ODN was demonstrated by its suppression of postischemic Fos expression, which was accompanied by an inhibition of ischemia-induced NGF mRNA expression in the dentate gyrus. Infusion of saline, the sense s-ODN, or a mismatch antisense s-ODN did not suppress Fos expression. That this effect of c-fos antisense s-ODN was specific to NGF was demonstrated by its lack of effect on the postischemic expression of the NT-3 and beta-actin genes. Our results demonstrate that c-fos antisense s-ODN blocks selected downstream events and support the contention that postischemic Fos regulates the subsequent expression of the NGF gene and that Fos expression may have a functional component in neuroregeneration after focal cerebral ischemia-reperfusion.

Renal cell carcinoma: unusual pediatric renal tumors

Renal cell carcinoma (RCC), the most common renal tumor in adults, is rare in childhood, with an incidence much lower than that of Wilms' tumor. It is initially asymptomatic, but clinically overt symptoms such as an abdominal mass or hematuria may indicate late-stage disease and a poor prognosis. In this report, we describe the imaging features of pediatric RCC and emphasize the value of early diagnosis offered by ultrasonographic screening. From 1989 through 1997, we encountered five children (aged 7-15 yr) with RCC. Of these, two presented with symptoms, while the other three were asymptomatic and were identified in a large, school-based urologic ultrasonographic survey, in which more than 800,000 children were screened by our team. Reviewing the imaging features, we found that four tumors exhibited a heterogeneous nature. One patient had bilateral well-defined homogeneous tumors, which proved to be bilateral low-grade RCC. The three asymptomatic patients had smaller tumors than the other two patients. These three were treated with nephrectomy and were well after at least 15 months of follow-up. The two patients who presented with symptoms eventually died of tumor recurrence and pulmonary metastasis, respectively. The findings in these five cases of pediatric RCC add knowledge regarding the imaging features of this disease and highlight the value of ultrasonographic screening for early diagnosis.

Knowledge-mediated retrieval of laboratory observations

Intelligent medical applications including agents, clinical decision support systems, and expert systems can benefit from components that expose the meanings of medical concepts. We have endeavored to create an ontology for laboratory observations and to make the ontology accessible in a distributed environment through a knowledge mediator offering several services. To date we have created two such services, one service to mediate the retrieval of laboratory observations and an auxiliary service to facilitate the mapping of units of measure to LOINC property-types. We report progress and insights on the development of our ontology and related knowledge mediator.

Congenital choanal atresia: computed tomographic and clinical findings

Congenital choanal atresia is a rare developmental anomaly characterized by failure of communication of the posterior nasal cavity with the nasopharynx. It may present as a component of the CHARGE association (C, coloboma; H, heart disease; A, atresia choanae; R, retarded growth and development; G, genital hypoplasia; and E, ear anomalies and/or deafness). The purpose of this study is to evaluate the computed tomographic (CT) appearance of membranous or bony type congenital choanal atresia. Six patients (4 females, 2 males; age range, 1 day to 8 weeks; mean, 13.8 days) with choanal atresia were included in this study and evaluated by CT scan. The CT clearly delineated the full anatomic abnormalities of choanal atresia. Among the 6 patients, three (50%) had bilateral membranous atresia, two (33%) had bilateral bony atresia, and one (17%) had unilateral (left) membranous atresia. Additionally, two (33%) patients (1 bilateral membranous atresia, 1 bilateral bony atresia) fit at least four of the six criteria in the CHARGE association. The CT plays a significant role in the diagnostic and therapeutic approach to congenital choanal atresia and should be the examination method of choice to evaluate neonates with nasal obstruction.

Switching transient analysis of a metal/ferroelectric/semiconductor switch diode with high speed response to infrared light

A thin PbTiO(3)-n-p(+) silicon switch diode has been developed, in which the switching voltage (the turned-on voltage) changes in proportion to the infrared light power. The diode has a rapid response time of 0.65 mus compared with other conventional infrared sensors. It is attributed to the rapid switching device structure and the smaller pyroelectric layer thickness, 50 nm. In this paper, we have analyzed the rapid switching transient response by using heat conduction and switching theory successfully. The experimental results are in agreement with the theoretical analysis.

Sensitive determination of a new antiarrhythmic agent, trecetilide, in plasma by high-performance liquid chromatography with fluorescence detection

Two high-performance liquid chromatography (HPLC) methods were developed for the determination of trecetilide in plasma samples. Differing only in the addition of a derivatization step and different detection wavelengths, the two methods encompassed a wide concentration range. In both methods, plasma samples (0.1 ml) with added internal standard were applied to solid-phase extraction discs containing a non-polar/strong cation mixed-phase, washed and eluted with an acetone-acetonitrile triethylamine mixture. The eluate was evaporated to dryness, and either reconstituted and directly injected onto an HPLC column or first derivatized with 1-naphthyl isocyanate before HPLC analysis. In both methods, the separation was performed isocratically on a cyano analytical column utilizing a mobile phase composed of acetonitrile-pH 7.9 phosphate buffer (70:30, v/v). The column effluent was monitored by fluorescence detection at 290/345 nm (with derivatization) or 235/320 nm (without derivatization). The limits of detection and quantitation of the assay were 0.57 and 1.9 ng/ml, respectively, when derivatization was used, or 4.3 and 14 ng/ml, respectively, without derivatization.

Effects of acute normovolemic hemodilution on T2*-weighted images of rat brain

Acute normovolemic hemodilution (HD) was induced in anesthetized rats to assess the effect of changes in hematocrit (Hct) on signal intensity in T2*-weighted magnetic resonance (MR) images. Other relevant physiological parameters were maintained invariant. Two degrees of HD were induced: mild (Hct reduced from 42.6+/-2.2% to 33.4+/-2.1%) and moderate (Hct reduced from 44.6+/-2.7% to 26.2+/-1.7%). A two-dimensional gradient-echo sequence was used to monitor signal changes with high temporal resolution before, during, and after HD protocols. The time course of signal intensity change was closely related to that of changes in Hct. Corresponding changes in R2* (deltaR2*) with respect to the pre-HD state were calculated for the brain parenchyma. Average deltaR2* values of -0.24+/-0.06 s(-1) and -0.40+/-0.07 s(-1) were obtained for the mild and moderate HD groups, respectively, during the final 2 min of MR imaging (proximal to correlative measurements of Hct). MR measured deltaR2* values were in close agreement with the expected changes in R2* predicted from theory when the measured changes in Hct were used as independent variables. These data are in good agreement with the current understanding of the effects of changes in the intravascular concentration of deoxyhemoglobin on induced magnetic susceptibility and hold promise for quantitative measurement of brain oxygenation in vivo.

Amyloid beta-peptide possesses a transforming growth factor-beta activity

Amyloid beta-peptide (Abeta) of 39-42 amino acid residues is a major constituent of Alzheimer's disease neurite plaques. Abeta aggregates (fibrils) are believed to be responsible for neuronal damage and dysfunction, as well as microglia and astrocyte activation in disease lesions by multiple mechanisms. Since Abeta aggregates possess the multiple valencies of an FAED motif (20th to 23rd amino acid residues), which resembles the putative transforming growth factor-beta (TGF-beta) active site motif, we hypothesize that Abeta monomers and Abeta aggregates may function as TGF-beta antagonists and partial agonists, analogous to previously described monovalent and multivalent TGF-beta peptide antagonists and agonists (Huang, S. S., Liu, Q., Johnson, F. E., Konish, Y., and Huang, J. S. (1997) J. Biol. Chem. 272, 27155-27159). Here, we report that the Abeta monomer, Abeta-(1-40) and its fragment, containing the motif inhibit radiolabeled TGF-beta binding to cell-surface TGF-beta receptors in mink lung epithelial cells (Mv1Lu cells). Abeta-(1-40)-bovine serum albumin conjugate (Abeta-(1-40)-BSA), a multivalent synthetic analogue of Abeta aggregates, exhibited cytotoxicity toward bovine cerebral endothelial cells and rat post-mitotic differentiated hippocampal neuronal cells (H19-7 cells) and inhibitory activities of radiolabeled TGF-beta binding to TGF-beta receptors and TGF-beta-induced plasminogen activator inhibitor-1 expression, that were approximately 100-670 times more potent than those of Abeta-(1-40) monomers. At less than micromolar concentrations, Abeta-(1-40)-BSA but not Abeta-(1-40) monomers inhibited proliferation of Mv1Lu cells. Since TGF-beta is an organizer of responses to neurodegeneration and is also found in neurite plaques, the TGF-beta antagonist and partial agonist activities of Abeta monomers and aggregates may play an important role in the pathogenesis of the disease.

Effect of acetic acid on telomerase activity in cervical intraepithelial neoplasia

OBJECTIVE

To evaluate whether the telomerase activity in CIN lesions can be affected by a chemical solution of acetic acid, which is required to apply to the cervix prior to colposcopy-directed biopsy.

MATERIALS AND METHODS

Thirty-five patients with histologically confirmed high-grade squamous intraepithelial lesions of the cervix entered the study. Two specimens were collected from each patient, one before and one after the cervix was swabbed with 5% acetic acid. The standard telomeric repeat assay protocol (TRAP) was used to examine telomerase activity in these fresh frozen tissue samples. Normal cervical tissues from 10 control individuals were also examined for the presence of telomerase activity. A total of 80 specimens was analyzed.

RESULTS

Telomerase activity was detectable in 27 of 35 (77.1%) fresh tissue samples, 15 of 35 (42.9%) tissue samples swabbed with 5% acetic acid, and 0 of 10 (0%) normal cervical tissue samples, respectively. Twelve samples became telomerase negative after 5% acetic acid applied. Among the 15 telomerase-positive tissue samples swabbed with 5% acetic acid, 12 had relative weak telomerase activity compared to corresponding fresh tissue samples, the other 3 remained the same. Therefore, it is concluded that telomerase activity was affected by 5% acetic acid in 24 of 27 (88.9%) samples. Telomerase activity in HeLa cell line was also inhibited by 5% acetic acid.

CONCLUSION

We reported a relative high percentage of telomerase expression in high-grade CIN lesions when compared with previous reports. If detection of telomerase activity is to become a tool for diagnosis and prognosis of cervical neoplasias, applying acetic acid prior to colposcopy-directed biopsy that is submitted for telomerase assay should be avoided in order to increase the detection rate.