Applications of a copper microparticle-modified carbon fiber microdisk array electrode for the simultaneous determination of aminoglycoside antibiotics by capillary electrophoresis

A copper microparticle-modified carbon fiber microdisk array electrode was fabricated and employed in capillary electrophoresis for the simultaneous determination of the five aminoglycoside antibiotics (AGs) including netilmicin, tobramycin, lincomycin, kanamycin and amikacin. The array electrode exhibited high catalytic activity for AGs, good reproducibility and stability. Under the optimum separation conditions (separation voltage of 6.2 kV, electrophoretic medium of 125 mM NaOH), the five AGs above were baseline separated within 20 min. At a working electrode potential of 0.7 V (versus saturated calomel electrode), the calibration curves were linear over two orders of magnitude of concentration, and the detection limits (SIN=3) were below 2 microM except for lincomycin (6.7 microM). The developed method was successfully employed for the simultaneous determination of the five AGs studied in pharmaceutical injections. The feasibility of this method for the simultaneous determination of lincomycin, kanamycin and amikacin in urine sample was also demonstrated.

Preoperative diagnosis by electron beam computed tomography and perioperative management of primary tracheal anomalies in tetralogy of Fallot

PURPOSE

To investigate the usefulness of electron beam computed tomography (EBCT) in the preoperative detection and perioperative management of insidious concomitant primary tracheobronchial anomalies in patients with tetralogy of Fallot (TF).

METHODS

From July 1995 to October 1999, 88 children (38 girls, 50 boys) with TF were enrolled in this study. EBCT examinations provided information needed to plan management. The final diagnoses of airway abnormalities were correlated with the findings of bronchoscopy in five patients and confirmed during surgery.

RESULTS

Fourteen (16%) of the 88 patients had associated primary tracheobronchial anomalies. Nine patients had tracheal bronchi, which were combined with tracheobronchial stenosis in two patients and with tracheal stenosis in one patient. Two patients had tracheal diverticulum, which was combined with lower tracheal stenosis in one patient. Two patients had congenital tracheal stenosis. Tracheomalasia was found in one patient. Three patients with ventilation difficulties died postoperatively. Special attention was given to the care of the diseased airways perioperatively, and the remaining 11 patients had a smooth course of hospitalization and discharge.

CONCLUSIONS

Our results show that EBCT provides good delineation of both cardiac and tracheobronchial anomalies and suggest that it should be used perioperatively to detect associated airway anomalies in TF, to facilitate the design of an appropriate ventilation care strategy.

Capsaicin and nonivamide as novel skin permeation enhancers for indomethacin

The study was conducted in vitro to investigate the changes of indomethacin transdermal permeation pretreated by capsaicin and nonivamide, two compounds chemically similar to Azone. The combined effect of low frequency ultrasound (20 kHz) and enhancers on the indomethacin permeation was also evaluated. The experimental data demonstrated that capsaicin and nonivamide significantly enhanced the flux of indomethacin across nude mouse skin. Enhancement effects of both analogues were very similar and depended predominantly on the concentration tested. Histological examination coupled with visual scores indicated the safety of capsaicin and nonivamide on skin structure. Simultaneous application of ultrasound and enhancers significantly increased skin permeation of indomethacin compared with either ultrasound or enhancers alone. Better effect was obtained by the combination with capsaicin than nonivamide.

A study on occupational exposure to petrochemicals and smoking on seminal quality

A cross-sectional study of 68 petrochemical workers (23 had never smoked [E/NS], 45 were current smokers [E/S]) and 130 subjects with no known history of exposure to petrochemicals (49 had never smoked [NE/NS], 81 were current smokers [NE/S]) was conducted to assess the effect of occupational exposure to petrochemicals and smoking on semen quality. In-person interviews revealed occupational history, smoking habit, and lifestyle. Semen parameters such as volume, viability, sperm forward progression rate, sperm density, and total sperm count were determined for all subjects. The results show that the E/NS workers had a lower sperm forward progression rate (P < .05) compared with controls (NE/NS). Individuals in the NE/S group showed a significant inverse relationship between years smoked and sperm density (r = -.24, P < .05). The data also revealed that cigarette smokers who had worked in a petrochemical plant had significantly poorer quality semen, including sperm density, total sperm count, and forward progression rate, compared with the control (NE/NS) group (P < .01). Furthermore, there was a significant inverse correlation between combined exposure and smoking years, and sperm density (r = -.28, P < .05). These findings suggest that occupational exposure to petrochemical compounds may aggravate the adverse effect that smoking has on semen quality.

A 2-year clinical study of composite and ceramic inlays

Objective long-term clinical data are necessary to evaluate the performance of dental restorations. This prospective clinical trial evaluated composite and ceramic inlays for clinical acceptability as restorative materials in posterior teeth and provided 2-year results. The study involved 7 student operators placing 47 composite inlays (Tetric, blend-a-lux, Pertac) and 24 ceramic inlays (Empress) under the supervision of an experienced dentist. Clinical assessment of 56 inlays (78.9%) was performed after 2 years with modified USPHS criteria and statistically analyzed using the Mann-Whitney U test and Fisher's exact test. All the ceramic inlays and 90% of the composite inlays were considered clinically excellent or acceptable. During the first year 3 composite inlays failed and during the second evaluation period 1 had to be replaced. Ceramic inlays produced significantly better "anatomic form of the surface" (P = 0.038) and "integrity of the restoration" values (P = 0.043). Inlays in small cavities exhibited superior "marginal integrity" (P = 0.026) and "marginal discoloration" values (P = 0.034). Fisher's test revealed a significantly higher failure rate in molars than in bicuspids (P = 0.034). Posterior tooth-colored inlays exhibited a success rate of 100% for ceramic inlays and 90% for composite inlays even if placed by relatively inexperienced but supervised student operators.

Voltammetric determination of mifepristone at a DNA-modified carbon paste electrode

A new strategy for the preparation of a DNA-modified carbon paste electrode is developed. It is found that the anodic response of mifepristone is greatly enhanced at the dsDNA-modified carbon paste electrode comparing with that obtained at the bare electrode, while the response at a ssDNA-modified electrode is similar to bare electrode. So the dsDNA-modified electrode is employed as a sensitive biosensor for the detection of mifepristone. A linear dependence of the peak currents on the concentration is observed in the range 2.0 x 10(-7) approximately 2.0 x 10(6) mol/L, with a detection limit of 1.0 x 10(-7) mol/L. The relative standard deviation is 4.3% for six successive determinations of 1.0 x 10(6) mol/L mifepristone. The determination of mifepristone tablets is carried out and satisfactory results are obtained.

Laparoscopic subsegmentectomy for hepatocellular carcinoma with cirrhosis: a case report

Laparoscopic liver resection is feasible for both benign and malignant disease with present laparoscopic techniques and technology. Laparoscopic liver tumor resection is indicated instead of the conventional hepatectomy if the tumor is located in the peripheral part of the liver. Here, we reported a case of a 73-year-old woman who accepted laparoscopic subsegmentectomy for hepatocellular carcinoma of segment 6. After traditional laparoscopic trocar was settled down under the low pneumoperitoneal pressure of 8 mm Hg, laparoscopic ultrasound allowed exact localization of lesions first and then transection line was marked. Then, dissection the liver parenchyma was carried out with laparoscopic microwave coagulator and ultrasonic aspirator gradually. After operation, she resumed full diet on the second day and was discharged on the 5th post-operative day with no complications and high patient satisfaction. She had follow-up study regularly in our clinic and was disease free at nine months. With the improvement of laparoscopic techniques and the development of new and dedicated technologies, laparoscopic hepatectomy has become feasible.

Mechanical properties of new composite restorative materials

OBJECTIVE

Determination of flexural strength, flexural modulus, fracture toughness, Vickers hardness, and wear resistance of condensable composites (Solitaire, Surefil, Alert) and an ormocer (Definite) in comparison with a hybrid composite (Tetric Ceram) and an ion-releasing composite (Ariston pHc).

METHODS

Flexural strength, flexural modulus, and fracture toughness were determined in 3-point bending. Single-edge notched-bend specimens were used to evaluate fracture toughness. Microhardness was measured with a Vickers indenter. Wear was determined in a pin-on-block-design with a Degusit antagonist at 50 N load and quantified by a replica technique after 6000, 10000, 30000, and 50000 load cycles using a 3D-laser scanner. All results were statistically analyzed with ANOVA and post hoc Tukey HSD tests.

RESULTS

Alert exhibited the highest flexural modulus, K(IC), and hardness, but lowest wear resistance. Solitaire presented the highest wear resistance, but significantly lower flexural strength, flexural modulus, K(IC), and hardness than all other materials. No significant correlation could be detected between hardness and wear of the tested composites with Pearson's correlation coefficient.

SIGNIFICANCE

The condensable composites differed significantly in their mechanical properties. This study suggested that, besides the filler content level and filler size, other factors like matrix-filler interactions highly influence the fracture and wear behavior of the materials.

Shear instabilities of freely standing thermotropic smectic- A films

In this Letter we discuss theoretically the instabilities of thermotropic freely standing smectic- A films under shear flow [3]. We show that, in Couette geometry, the centrifugal force pushes the liquid crystal toward the outer boundary and induces smectic layer dilation close to the outer boundary. Under strong shear, this effect induces a layer buckling instability. The critical shear rate is proportional to 1/sqrt[d], where d is the thickness of the film.

Clinical correlates of antifungal macrodilution susceptibility test results for non-AIDS patients with severe Candida infections treated with fluconazole

Although the clinical correlates of the reference antifungal susceptibility test results in hematogenous and deep-seated Candida infection are still controversial, we evaluated the clinical correlates of this test in deep-seated Candida infections in non-AIDS patients. Thirty-two non-AIDS patients with hematogenous or deep-seated Candida infections were treated with intravenous fluconazole (400 mg a day), and the clinical outcomes were evaluated. Coexisting bacterial infections were treated with appropriate antibiotics, superinfection or reinfection was excluded, inadequate fluconazole therapy was avoided, and essential surgical intervention was performed. The MICs of fluconazole for these 32 Candida isolates were determined according to the M27-A procedure approved by the National Committee on Clinical Laboratory Standards. MICs were interpreted as susceptible (< or =8 microg/ml), dose-dependent susceptible (16 to 32 microg/ml), and resistant (> or =64 microg/ml) according to the criteria of the M27-A standard. The success rates were 79% (19 of 24; 95% confidence interval [CI], 59 to 93%) in the susceptible category, 66% (4 of 6; 95% CI, 19 to 95%) in the dose-dependent susceptible category, and 0% (0 of 2; 95% CI, 0 to 84%) in the resistant category. We conclude that the clinical correlation of the reference antifungal susceptibility test results is high in hematogenous and deep-seated Candida infections.

Effect of polyclonal anti-TNFalpha antibody on endotoxic shock in suckling rats

The aim of this study was to evaluate the effect of anti-tumor necrosis factor alpha (TNFalpha) antibodies on the TNFalpha gene expression in a neonatal septic shock model. Ten-day-old Sprague-Dawley rats were divided into four groups and given intraperitoneal (ip) injection as follows: group 1: 0.1 ml saline; group 2: 0.1 mg/kg Salmonella enteritidis lipopolysaccharide (LPS); group 3: 1 mg/kg of anti-TNFalpha antibodies (Ab); group 4: 0.1 mg/kg of LPS and 1 mg/kg of Ab. We found that in group 2, LPS induced shock, demonstrating hypoglycemia and lactacidemia (p < 0. 05) and death (81.8%). Ab decreased the mortality significantly (35%) and attenuated the hypoglycemia (35 +/- 8 mg/dl in group 2 vs. 53 +/- 3 mg/dl in group 4) and lactacidemia (5.40 +/- 0.63 vs. 2.35 +/- 0.45 mmol) at 8 h in group 4 when compared to group 2. Northern blot demonstrated a significant decrease in TNFalpha mRNA expression in group 4 as compared to group 2, at 2 h after LPS injection. We conclude that the beneficial effects of anti-TNFalpha antibodies on LPS-induced shock may be due to decreased TNFalpha gene expression.

Esophageal varices in congenital heart disease with total anomalous pulmonary venous connection

Total anomalous pulmonary venous connection (TAPVC) is an uncommon congenital anomaly in which the anatomical presentations vary widely among patients. We hereby present two newborns with TAPVC associated with asplenia syndrome; both had severe esophageal varices due to infradiaphragmatic pulmonary venous drainage. Ultrafast computed tomography (CT) scanning was superior to color Doppler echocardiography and cardiac catheterization as it provided a detailed portrait of the pulmonary drainage. The remarkable radiographic manifestations are presented.

Inactivation of the mouse melanocortin-3 receptor results in increased fat mass and reduced lean body mass

Genetic and pharmacological studies have defined a role for the melanocortin-4 receptor (Mc4r) in the regulation of energy homeostasis. The physiological function of Mc3r, a melanocortin receptor expressed at high levels in the hypothalamus, has remained unknown. We evaluated the potential role of Mc3r in energy homeostasis by studying Mc3r-deficient (Mc3r(-/-)) mice and compared the functions of Mc3r and Mc4r in mice deficient for both genes. The 4-6-month Mc3r-/- mice have increased fat mass, reduced lean mass and higher feed efficiency than wild-type littermates, despite being hypophagic and maintaining normal metabolic rates. (Feed efficiency is the ratio of weight gain to food intake.) Consistent with increased fat mass, Mc3r(-/-) mice are hyperleptinaemic and male Mc3r(-/-) mice develop mild hyperinsulinaemia. Mc3r(-/-) mice did not have significantly altered corticosterone or total thyroxine (T4) levels. Mice lacking both Mc3r and Mc4r become significantly heavier than Mc4r(-/-) mice. We conclude that Mc3r and Mc4r serve non-redundant roles in the regulation of energy homeostasis.

Painful fourth cranial nerve palsy caused by posteriorly-draining dural carotid-cavernous sinus fistula

A 65-year-old man with a dural carotid-cavernous fistula (DCCF) presented with sudden onset of painful trochlear nerve paresis. Typical signs of DCCF including conjunctival arterialization, chemosis, and proptosis did not become manifest until 4 months later. This unusual presentation of DCCF was caused by drainage of the fistula posteriorly into the inferior petrosal sinus with low flow. With this condition, patients may present with trochlear nerve palsy without a red eye. Although rare, DCCF must be considered in patients presenting with isolated painful trochlear palsy.

Laparoscopic subsegmentectomy for hepatocellular carcinoma with cirrhosis

BACKGROUND/AIMS

Laparoscopic liver resection is feasible for both benign and malignant disease with today's laparoscopic techniques and technology. Location of the tumor at the edge of segment 3, 4, 5, or 6 of our patients makes them an ideal candidate for laparoscopic resection.

METHODOLOGY

There were 9 patients who underwent laparoscopic subsegmentectomy for hepatocellular carcinoma with cirrhosis. They were classified as Child A in 6 and B in 3 patients. Hepatitis B was found in 5 and Hepatitis C in 4 cases. Preoperative diagnosis of hepatocellular carcinoma was completed in 7 and definitive histologic diagnosis from frozen section in 2 cases. All 9 patients underwent subsegmentectomy and removal of the tumor with non-tumor cirrhotic liver with a distance of 10 mm at the least margin. Laparoscopic ultrasound allows exact localization of lesions and achievement of adequate resection margin.

RESULTS

Those patients resumed a full diet on the 2nd-3rd day after the operation and were discharged home on day 4-7 with no complications but one had prolonging discharge due to ascitis from a drainage tube. Finally, the ascitis was controlled by medications for 1 week. All patients had high postoperative satisfaction.

CONCLUSIONS

Laparoscopic liver resection is a procedure of significant risk and technically demanding. Therefore, it should be performed only by experienced liver surgeons with a high level of laparoscopic skill and in the carefully selected patient.

Interface and contact line motion in a two phase fluid under shear flow

We use a coarse grained description to study the steady state interfacial configuration of a two phase fluid under steady shear. Dissipative relaxation of the order parameter leads to interfacial slip at the contact line, even with no-slip boundary conditions on the fluid velocity. This relaxation occurs within a characteristic length scale l(0) = sqrt[xiD/V0], with xi the (microscopic) interfacial thickness, D an order parameter diffusivity, and V0 the boundary velocity. The steady state interfacial configuration is shown to satisfy a scaling form involving the ratio l(0)/L, where L is the width of the fluid layer, for a passive interface, and the capillary number as well for an active interface.

Prognostic value of p53 expression in stage IB1 cervical carcinoma

The purpose of this retrospective study was to evaluate the patterns of p53 expression in stage IB1 squamous cell carcinoma of the uterine cervix, to compare p53 expression with clinicopathological findings, and to assess its prognostic value. 27 patients with stage IB1 squamous cell carcinoma of the uterine cervix underwent abdominal radical hysterectomy and pelvic lymph node dissection. Expression of p53 was studied immunohistochemically. Overexpression of p53 was detected in 33.3% of the tumors, low expression was seen in 11.1%, and negative expression was found in 55.6%. Deep cervical stromal invasion (> or = 1/2) was found to be associated with the increased risk of lymph node metastases (odds ratio = 17.5). A significantly lower percentage of patients survived when p53 overexpression was observed (p = 0.0315). Univariate analysis revealed that tumor size (2-3.9 cm), lymph node metastasis, tumor invasion into parametria, tumor invasion into blood/lymph vessels, squamous cell carcinoma antigen (> or = 2 ng/ml), and p53 overexpression had a significantly lower recurrence-free survival rate. None of these above factors obtained significance in the multivariate analysis. This study suggests that expression of p53 may be indicative of an unfavorable prognosis in patients with stage IB1 squamous cell carcinoma of the uterine cervix.

Immunomodulation by dietary beta-1, 3-glucan in the brooders of the black tiger shrimp Penaeus monodon

The present study evaluated the effectiveness of beta-1,3-glucan derived from Schizophyllum commune in enhancing shrimp survival as well as haemocyte phagocytosis and superoxide anion production in brooder Penaeus monodon. Pond-reared P. monodon adults (135 +/- 25 g) stocked in outdoor or indoor tanks were fed either a test diet containing beta-1,3-glucan (2.0 g kg(-1) or a glucan-free control diet for 40 days. Their survival was compared. The brooders reared in indoor tanks were analysed at days 0, 1, 3, 6, 12, 24, 30 and 40 for their haemocyte phagocytic activity and superoxide anion production. The results showed that regardless of indoor or outdoor rearing the survival rate of shrimp fed the glucan diet was significantly higher (P<0.001) than that of the control group. The brooders showed enhanced haemocyte phagocytic activity, cell adhesion and superoxide anion production when glucan was administered in their diets. The immunostimulatory enhancement peaked at day 24 after starting the dietary exposure and subsequently decreased to the pre-feeding level at the end of the 40 days feeding trial.

Assessment of fetal cerebellar volume using three-dimensional ultrasound

The purposes of this study were to assess the fetal cerebellar volume during normal gestation using three-dimensional (3-D) ultrasound (US) and to establish a normal chart of fetal cerebellar volume using Altman's model of statistics. In total, 231 healthy fetuses were studied for assessment of cerebellar volume using a 3-D US volume scanner. The fetuses to be studied were selected to give a cross-sectional series (i.e., each fetus was examined only once). Polynomial regression analysis was calculated to find the best-fit model using gestational age as the independent variable and cerebellar volume as the dependent variable. Altman's model was used to calculate the age-related reference centiles for the variance of cerebellar volume. In addition, common fetal growth indices, such as biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference, femur length and estimated fetal weight, were also measured for the correlation between cerebellar volume and these indices. Our results indicated that the fetal cerebellar volume was highly correlated with gestational age in normal pregnancies with the best-fit polynomial regression equation of a second-order (r = 0.91, p < 0.0001). In addition, fetal cerebellar volume in normal gestation is also highly correlated with common fetal growth indices, such as biparietal diameter, occipitofrontal diameter, head circumference, abdominal circumference, femur length and estimated fetal weight (all p < 0.0001). Following the Altman's model, a normal growth chart of fetal cerebellar volume was established for clinical reference. In conclusion, with 3-D US, the assessment of fetal cerebellar volume becomes feasible. We believe that fetal cerebellar volume assessed by 3-D US may be useful in detecting cerebellar hypoplasia and relevant syndromes prenatally.

Systemic assessment of fetal hemodynamics by Doppler ultrasound

The aim of our study was to investigate the parameters of fetal circulation of normal pregnancies and their relationship to fetal cardiac output. We performed a cross-sectional study of 315 normal singleton pregnancies between 20 and 40 weeks' gestation without fetal chromosomal or structural malformations. After follow-up to delivery, 212 patients who fit all the criteria were enrolled for final analysis. Blood flow velocity waveforms were obtained from the tricuspid and mitral ventricular inflow, ascending aorta (AAO), pulmonary artery (PA), middle cerebral artery (MCA), renal artery (RA), umbilical artery (UA), descending aorta (DAO), inferior vena cava (IVC) and ductus venosus (DV) using duplex (real-time Doppler) ultrasound (US) scanner. The peak velocity of DV, AAO, PA and MCA were also obtained. At the intracardiac level, the ratio of peak flow velocity of E wave to peak flow velocity of A wave (E:A ratio) of mitral valve (MV) increased more rapidly than tricuspid valve (TV) E:A ratio. For the great vessels, aortic peak velocity remained higher than the pulmonary peak velocity with advancing gestation. The cardiac output closely correlated to the cardiac compliance and flow resistance indices at arterial and venous level. The acceleration time in the fetal arteries increased with advancing gestation in AAO, PA, MCA and DAO, but it decreased in RA and kept constant in UA. In addition, the acceleration time of UA was unrelated to cardiac output. The changes of the fetal intracardiac, arterial and venous impedances were remarkable through the gestation and related to cardiac output. Fetal cardiac output correlated well with the changes of arterial resistance, except with the DAO. The ventricular compliance increased with advancing gestation, especially in the left side, and was highly related to the change of cardiac output. The acceleration time in major arteries positively correlated with the gestational age and cardiac output, except in UA and RA; this indicates the difference of the changes of mean arterial pressure in uteroplacental circulation, fetal organs and great vessels. In conclusion, the fetal cardiac output correlated well with the ventricular compliance and was influenced by both hemodynamic changes in peripheral resistance and mean arterial pressure.

Fetal ear assessment and prenatal detection of aneuploidy by the quantitative three-dimensional ultrasonography

The purposes of this study were to use quantitative three-dimensional (3-D) ultrasonography to establish the normal charts of three fetal ear-growth indexes, (ear length, ear width and ear area), and to validate their efficacy in the prenatal diagnosis of fetal trisomies, either separately or as a combination. Using quantitative 3-D ultrasonography, we performed a prospective study to measure the three fetal ear growth indexes (i.e., ear length, ear width and ear area) in 129 singleton pregnancies, including 122 normal fetuses and 7 trisomies. The ear shape was also evaluated in these fetuses using both 2-D and 3-D ultrasonography. Our results showed that: First, 3-D ultrasonography offers better visualization and easier evaluation of fetal ears than 2-D ultrasonography. Second, when using the quantitative assessment of 3-D ultrasonography, the measurements of ear length, ear width and ear area were all correlated significantly with gestational age in normal pregnancies (r = 0.881, 0.848, and 0.890, respectively). In addition, 3 of 7 fetal trisomies had ear length below the tenth percentile, 1 had ear width below the tenth percentile, and 2 had ear area below the tenth percentile. Furthermore, with the combination of these three measurements, (including ear length, ear width and ear area), the sensitivity in detecting fetal trisomies was elevated to 57.1% and the specificity was 83.2%. In conclusion, 3-D ultrasonography reduces the limitations of 2-D ultrasonography in the evaluation of fetal ears. However, fetal ear measurement may not be used as a single ultrasonographic parameter in identifying aneuploid fetuses. We recommend using the combination of these three ear growth indexes to enhance the detection rate of aneuploidy.

Mouse mammary tumor virus-Ki-rasB transgenic mice develop mammary carcinomas that can be growth-inhibited by a farnesyl:protein transferase inhibitor

For Ras oncoproteins to transform mammalian cells, they must be posttranslationally modified with a farnesyl group in a reaction catalyzed by the enzyme farnesyl:protein transferase (FPTase). Inhibitors of FPTase have therefore been developed as potential anticancer agents. These compounds reverse many of the malignant phenotypes of Ras-transformed cells in culture and inhibit the growth of tumor xenografts in nude mice. Furthermore, the FPTase inhibitor (FTI) L-744,832 causes tumor regression in mouse mammary tumor virus (MMTV)-v-Ha-ras transgenic mice and tumor stasis in MMTV-N-ras mice. Although these data support the further development of FTIs, it should be noted that Ki-ras is the ras gene most frequently mutated in human cancers. Moreover, Ki-RasB binds more tightly to FPTase than either Ha- or N-Ras, and thus higher concentrations of FTIs that are competitive with the protein substrate may be required to inhibit Ki-Ras processing. Given the unique biochemical and biological features of Ki-RasB, it is important to evaluate the efficacy of FTIs or any other modulator of oncogenic Ras function in model systems expressing this Ras oncoprotein. We have developed strains of transgenic mice carrying the human Ki-rasB cDNA with an activating mutation (G12V) under the control of the MMTV enhancer/promoter. The predominant pathological feature that develops in these mice is the stochastic appearance of mammary adenocarcinomas. High levels of the Ki-rasB transgene RNA are detected in these tumors. Treatment of MMTV-Ki-rasB mice with L-744,832 caused inhibition of tumor growth in the absence of systemic toxicity. Although FPTase activity was inhibited in tumors from the treated mice, unprocessed Ki-RasB was not detected. These results demonstrate the utility of the MMTV-Ki-rasB transgenic mice for testing potential anticancer agents. Additionally, the data suggest that although the FTI L-744,832 can inhibit tumor growth in this model, Ki-Ras may not be the sole mediator of the biological effects of the FTI.

Matrix metalloproteinase-8 levels and elastase activities in gingival crevicular fluid from chronic adult periodontitis patients

AIM

To make an initial assessment of the periodontal diagnostic potential of immunoreactive matrix metalloproteinase-8 (MMP-8) in gingival crevicular fluid (GCF) by comparison with elastase activity which has previously been associated with disease severity and progression.

METHODS

GCF was collected from molar and premolar sites of 16 chronic adult periodontitis patients before treatment and 13 of this group 2 weeks after scaling and root planing. Samples were analysed for MMP-8 by immunofluorometric assay and for elastase activity with a fluorogenic substrate.

RESULTS

Mean patient clinical parameters and GCF enzyme totals both decreased significantly after treatment. Total MMP-8 levels and elastase activities generally correlated significantly with gingival and bleeding indices. For GCF concentrations, only MMP-8 showed a significant fall after treatment, and some significant correlations with clinical parameters. Amounts of the 2 enzymes correlated significantly with each other.

CONCLUSIONS

Similarities between MMP-8 and elastase probably reflect the fact that both enzymes are associated mainly with neutrophils: MMP-8 levels may have fallen more after treatment because the assay, unlike that for elastase, would most likely not have detected much enzyme bound to alpha-macroglobulin. The immunoassay for MMP-8 is more specific and convenient than functional collagenase assays, and might be suitable for monitoring the periodontal condition.