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PubMed1980

A computer analysis of specific and aspecific interictal epileptic activity in man.

The preliminary results are reported for a systematic computerized analysis of interictal EEG recordings from patients with different epileptic syndromes. Both interical specific epileptic activity and non-specific background EEG signals are processed by special programs. Specific achievement are: a) Automatic recognition of spikes and quantification in every channel of their temporal incidence; b) definition of morphology and temporal relationship among spikes simultaneously recorded from different cortical and subcortical structures. Non-specific achievement: a) Characterization of background pattern; b) identification, quantification and localization of pathological frequencies. The study of changes in the described parameters induced by pharmacological therapies and measured drug plasma levels, has supplied additional criteria for the evaluation of epileptic dynamics and the monitoring of optimal treatment modes.

Computers↗

PubMed2005

Preoperative serum squamous cell carcinoma antigen levels in clinical decision making for patients with early-stage cervical cancer.

PURPOSE: To prevent morbidity associated with double modality treatment, early-stage cervical cancer patients should only be offered surgery when there is a low likelihood for adjuvant radiotherapy. We analyzed whether serum squamous cell carcinoma antigen (SCC-ag) analysis allows better preoperative identification of patients with a low likelihood for adjuvant radiotherapy than currently used clinical parameters. PATIENTS AND METHODS: In a cohort study, International Federation of Gynecology and Obstetrics (FIGO) stage, tumor size, and preoperative serum SCC-ag levels, as determined by enzyme immunoassay, were related to the frequency of postoperative indications for adjuvant radiotherapy in 337 surgically treated, FIGO stage IB/IIA, squamous cell cervical cancer patients. RESULTS: In patients with normal preoperative SCC-ag, 16% of IB1 and 29% of IB2/IIA had postoperative indications for adjuvant radiotherapy, in contrast to 57% of IB1 and 74% of IB2/IIA patients with elevated (> 1.9 ng/mL) serum SCC-ag (P < .001). Serum SCC-ag was the only independent predictor for a postoperative indication for radiotherapy (odds ratio, 7.1; P < .001). Furthermore, in IB1 patients that did not have indications for adjuvant radiotherapy, 15% of patients with elevated preoperative serum SCC-ag levels recurred within 2 years, compared with 1.6% of patients with normal serum SCC-ag levels (P = .02). CONCLUSION: In early-stage cervical cancer, determination of serum SCC-ag levels allows more refined preoperative estimation of the likelihood for adjuvant radiotherapy than current clinical parameters, and simultaneously identifies patients at high risk for recurrence when treated with surgery only. The role of preoperative serum SCC-ag in the management of patients with early-stage cervical cancer deserves further investigation.

Adult↗

PubMed1980

Age-related abnormalities of circulating polyamines and diamine oxidase activity in cystic fibrosis heterozygotes and homozygotes.

Serum putrescine (Pu), spermidine (Sd), spermine (Sp), and plasma diamine oxidase ativity (DAO) were determined in cystic fibrosis (CF) homozygotes and heterozygotes plus age-matched controls. Mean (+/- S.E.) levels of Pu (0.51 +/- 0.06 nmoles/ml), Sd (0.63 +/- 0.07 nmoles/ml), and Sp (0.33 +/- 0.08 nmoles/ml) were higher (P < 0.001) in 17 control children versus 16 healthy adults (Pu = 0.15 +/- 0.04; Sd = 0.14 +/- 0.03; Sp = 0 in all). All 4 CF adults tested, but only 3 of 24 CF children, had increased polyamines relative to age-matched controls. Pu (0.33 +/- 0.04), Sd (0.33 +/- 0.05) and Sp (0.16 +/- 0.12) were increased (P < 0.001) in 11 adult heterozygotes; in turn, Pu (0.56 +/- 0.11; P < 0.025) and Sd (0.86 +/- 0.22; P < 0.005) were higher in the adult CF patients than in the heterozygotes. Plasma DAO was higher (P < 0.001) in 45 control children (9.3 +/- 0.7 units/ml) versus 61 healthy adults (5.7 +/- 0.07). Levels greater than or equal to +2 S.D. for controls occurred in 8 (21%) of 39 CF patients. Plasma DAO (19 +/- 4.8) was increased (P < 0.001) in 27 adult heterozygotes; 10 (37%) had values greater than or equal to +2 S.D. for normal adults. One or more polyamines and/or DAO were increased in each of 11 heterozygotes in whom all parameters were measured. These composite abnormalities might be considered as a potential means for identification of asymptomatic CF heterozygotes.

Adolescent↗

PubMed2006

Relative levels of semen platelet activating factor-receptor (PAFr) and ubiquitin in yearling bulls with high content of semen white blood cells: implications for breeding soundness evaluation.

High content of the platelet activating factor (PAF) and its plasma membrane receptor (PAFr) in semen is thought to benefit fertility in farm animals and humans. We used flow cytometric, biochemical, and immunocytochemical analysis to examine PAFr levels alone (Trial 1, n = 156 bulls) or in a dual assay with sperm defect marker ubiquitin (UBI; Trial 2, n = 88 bulls), in semen samples from 160 yearling bulls undergoing Breeding Soundness Evaluations (BSE). In both trials, we observed increased PAFr levels in semen samples with high content of white blood cells (WBC). Consequently, PAFr levels within such semen samples correlated negatively with several subjective parameters of BSE, including palpation, satisfaction of evaluation, and scrotal circumference. Due to a high WBC content, increased semen sample dilution had to be applied for microscopic evaluation. There was a negative correlation between semen PAFr and conventional sperm morphology, while the increased levels of PAFr correlated positively with sperm UBI content. Immunofluorescence microcopy revealed high expression of PAFr on the surface of leukocytes and morphologically normal spermatozoa, while reduced immunoreactivity was observed in defective spermatozoa immunoreactive to anti-UBI antibodies. A single PAFr band of appropriate mass was observed in Western blots of ejaculated spermatozoa, while testicular and epididymal spermatozoa also displayed several larger bands indicative of posttranslational processing or modification. Collectively, these data suggest that high levels of semen PAFr in young bulls are indicative of semen contamination with WBC. In the future, objective protein marker-based semen analyses in young bulls will likely require additional parameters distinguishing between marker expression in the spermatozoa and in the contaminating WBC. While identification of high sperm PAFr levels may support fertility, this assay alone is not reliable, due to the expression of PAFr in WBC that contaminate semen samples.

Animals↗

PubMed1979

[Cryoglobulin analysis by ultracentrifugation in density stabilized gradient followed by immunodiffusion (author's transl)].

A technique is described which combines ultracentrifugation in a density gradient stabilized by gelification, with agar gel immunodiffusion. The use of this procedure to determine sedimentation parameters and antigenic determinations is presented and illustrated with the diagramms obtained in the identification of various cryoglobulins.

Centrifugation, Density Gradient↗

PubMed2002

[Determination of eight trichothecene mycotoxins using GCMSMS methods. I. elaboration of MS/MS conditions].

Trichothecene mycotoxins are commonly distributed in cereals in the world. Rapid and accurate methods for the determination of these toxins are required to prevent the intoxication of human and to contribute to the supply of safe foods and feed. MSMS mode was applied for identification of eight trichothecene mycotoxins with Finnigan/Mat GCQ GC/MS system. We describe here optimal parameters of CID and to obtain best pairs of ions (precursor ions and daughter ions) for all analysed toxins.

Edible Grain↗

PubMed1999

[Study on chromatographic peak identification by means of peak shape analysis].

A new method for chromatographic peak identification by means of peak shape analysis is presented in this paper. Directly measurable parameters, i.e. peak width and asymmetry factor are first utilized for peak shape analysis. It is showed from theoretical and experimental results that for a component having almost the same retention time with the standard, an overlapped peak can be obtained by injecting the mixture of analyte and standard. In comparing the peak shape of overlapped peak with the standard one, the component can be identified whether it is the same with the standard or not.

Chromatography↗

PubMed1992

[The isolation of highly purified bacillary ribonucleases from recombinant strains of Escherichia coli].

Active and inactive highly purified extracellular alkaline ribonucleases (barnase) from recombinant Escherichia coli have been prepared according to the industrial technology of Bacillus intermedius ribonuclease purification. Electrophoretic parameters and ultraviolet spectra characterize these preparations as homogeneous proteins. Immunochemical test system of identification of inactive RNAse for its purification has been worked out.

Animals↗

PubMed2003

[Quantitative pathologic technique in prognostic identification of breast carcinoma with negative lymph node].

OBJECTIVE: To study the prognostic identification of lymph node negative breast carcinoma by quantitative pathologic technique. METHODS: Several morphometrical parameters, DNA content of cell nuclei were detected by means of a quantitative pathologic technique on 102 patients with lymph node negative invasive breast duct carcinoma. The effects of potential prognostic factors of lymph node negative breast cancer patients were assessed by Cox's proportional hazards regression model. RESULTS: DNA index, minimal diameter of nuclei, area of nuclei, maximal diameter of nuclei, and the perimeter of nuclei are important factors to influence the prognosis. CONCLUSION: Quantitative pathologic technique combined with valid statistical methods, as an objective means of assessing prognosis, may reliably improve the outcome in lymph node negative breast cancer.

Adult↗

PubMed2004

Evolutive algorithms for beat-by-beat estimation of left ventricular mechanics.

Traditional methods to evaluate the ventricular mechanics need intraventricular pressure and volume recordings for multiple variably loaded beats. To do this, a complex and invasive procedure must be applied, that may decrease the clinical use. To overcome this limitation, a method to estimate the ventricular mechanics beat-by-beat is presented, modeling the ventricular pressure-volume relationship with a time-varying elastance function. The ability of the genetic algorithms (GAs) as identification technique is exploited. Applying GAs on surrogated data simulating variably loading conditions, the parameters of the time-varying elastance function, considered a measure of the contractility of the myocardial fibers are identified. These single-beat estimates are highly correlated with the end systolic pressure-volume relationship slope obtained by conventional multiple-beat analysis. The main advantage in using GAs for single beat analysis may lie, in the perspective of an use for in vivo investigations, both in their stochastic nature, and in the guaranteed better performance with respect to other search techniques on problems involving noisy signals. Future studies will approach the reduction in GAs computational costs, for a real time in vivo application.

Algorithms↗

PubMed2005

Acute sleep responses in a normobaric hypoxic tent.

PURPOSE: Sleeping in a hypoxic environment is becoming increasingly popular among athletes attempting to simulate a "live high, train low" training regime. The purpose of this study was to investigate the acute effects (one night) of sleeping in a normobaric hypoxic tent (NH) (PO(2) = 110 mm Hg approximately 2500 m) upon markers of sleep physiology and quality, compared with sleep in a normal ambient environment (BL) (PO(2) = 159 mm Hg approximately sea level) and sleep in a normobaric normoxic tent (NN) (PO(2) = 159 mm Hg). METHODS: Eight male recreational athletes (age 34.5 +/- 6.9 yr; stature 169.1 +/- 8.7 cm; mass 69.3 +/- 8.2 kg; VO(2max) 56.4 +/- 8.3 mL.kg(-1).min(-1)) participated in the study using a randomized, double-blind crossover design. Polysomnographic studies were undertaken to measure sleep stages, arterial oxygen saturation (SpO(2)), heart rate (HR), and the Respiratory Disturbance Index (RDI). The Leeds Sleep Evaluation Questionnaire (LSEQ) was used to measure subjective sleep quality. RESULTS: NH (89.9 +/- 4.8%) resulted in a significantly lower (P < 0.05) SpO(2) compared with both BL (95.7 +/- 1.5%) and NN (93.5 +/- 4.0%). Heart rate was significantly higher (P < 0.05) in NH (51.5 +/- 7.6 beats.min(-1)) compared with NN (48.3 +/- 6.9 beats.min(-1)) but was similar versus BL (50.3 +/- 4.3 beats.min(-1)). RDI (counts.h) and RDI (total counts) were lowest in BL (3.5 +/- 2.5; 18.1 +/- 7.9) and highest in NH (36.8 +/- 42.7; 221.9 +/- 254.5). The difference in RDI (counts.h(-1) and total counts) between NH and BL was significant (P < 0.05). The LSEQ revealed that subjects' "behavior following waking" score was significantly (P < 0.05) lower in NH (40.9 +/- 9.2) compared with BL (52.3 +/- 8.3). CONCLUSION: This study presents evidence that sleep in a normobaric hypoxic tent at a simulated altitude of 2500 m may affect sleep parameters in some individuals. This type of analysis may be useful in the early identification of poorly responding individuals to simulated altitude environments.

Adult↗

PubMed1990

Monoclonal antibody B-ly7: a sensitive marker for detection of minimal residual disease in hairy cell leukemia.

The new monoclonal antibody (MoAb) B-ly7 was tested for its value in bone marrow diagnosis in patients with hairy cell leukemia (HCL). Cryostat sections of bone marrow biopsies were examined by an indirect immunoperoxidase technique. Lymphoma cells from all of 26 HCL cases investigated displayed strong surface membrane staining with the MoAb B-ly7, whereas tumor cells from only one of 63 patients with other lymphoproliferative disorders of B cell type reacted with this antibody. The strong reactivity of hairy cells (HCs) with this marker was not altered after therapy as demonstrated on control biopsies taken from patients treated with interferon(IFN)-alpha-2 or 2'deoxycoformycin(DCF) six-64 weeks after start of treatment. This fact as well as the very low number of B-ly7 positive cells found in a series of 13 normal bone marrow biopsies (mean: 0.3% of bone marrow cells, range: 0.0%-1.0%), which could easily be distinguished from HCs by their lower staining intensity and their morphological appearance, provided the basis for the detection of even single HCs. In our hands, in terms of sensitivity the immunohistological detection of HCs using the MoAb B-ly7 was not only superior to classical morphological techniques but also to other immunohistological parameters usually applied for this purpose. Therefore, this MoAb provides a marker for the identification of HCs, hence monitoring disease activity in HCL, and particularly for a critical response evaluation in patients undergoing treatment with IFN-alpha or DCF.

Antibodies, Monoclonal↗

PubMed1995

Effect of structured postgraduate medical education on the care of patients with diabetes.

BACKGROUND: Diabetes can be effectively treated and monitored in general practice. Postgraduate medical education at a local level is required to support this strategic shift of medical care from hospital to general practice. AIM: This study set out to determine whether a structured educational programme initiated by and led by general practitioners, but involving all health professionals, leads to improved care for diabetic patients. METHOD: The primary health care teams from 12 of the general practices in Tynedale, Northumberland who attend the local postgraduate centre and refer patients to the local general hospital were involved in the educational initiative which led to a locally agreed protocol for diabetic care. A comparison was made of data for all diabetic patients, registered with the general practitioners in 1991, in the years 1986 and 1991 (before and after the educational initiative) in order to determine the prevalence of diabetes, place of care and treatment received, and to collect clinical information. RESULTS: More patients received general practice care only or shared care in 1991 than in 1986. There was a reduction in the use of oral hypoglycaemic agents among non-insulin dependent diabetic patients and more patients were maintained on diet alone. A greater proportion of patients were referred to dietitians, ophthalmologists and chiropodists in 1991 than 1986, and there was increased recording of, examination of, and identification of, diabetic complications. Little change was found in the mean values for clinical parameters between the two years. CONCLUSION: Structured educational programmes involving all professionals are an effective way of producing protocols that are adhered to by all concerned, and lead to improved clinical care for diabetic patients.

Clinical Protocols↗

PubMed1993

Noncontact photoacoustic spectroscopy during photoablation with a 193-nm excimer laser.

Photoablation with the 193-nm excimer laser in organic and inorganic material generates an audible sound wave; in a clinical context, this helps to determine when effective photoablation is taking place. We investigated whether the acoustic phenomenon would qualify as a quantitative parameter of photoablation during non-contact photoacoustic spectroscopy (NCPAS). Photoablation was performed with a 193-nm excimer laser at a fluence of 80-330 mJ/cm2 and ablation-zone diameters ranging between 1.2 and 5.13 mm. A capacitor microphone (Broel & Kjaer) emitted a time signal that was processed for Fourier transformation (FT, spectrum of frequency). The following elements of the FT-signal were studied: the integral, the amplitude, the half-value, and the location of the center frequency. The integral and the amplitude were correlated linearly with the fluence. Variation of the ablation-zone diameter between 1.2 and 5.13 mm was found to produce a squared increase of the integral and the amplitude (fluence, 180 mJ/cm2). The half-value and the center of frequency of the FT signal were constant for the same target material but varied between materials. NCPAS may qualify for the future control of various photoablation and laser parameters such as incision depth, ablation-zone diameter, fluence, and target-material identification and discrimination. Its advantage over competing optical methods is its independence from optical target properties (e.g., fluorescence, surface roughness, reflectivity).

Acoustics↗

PubMed1996

Prognostic significance of bcl-2 protein expression in aggressive non-Hodgkin's lymphoma. Groupe d'Etude des Lymphomes de l'Adulte (GELA).

Little is known about the expression of bcl-2 protein in intermediate and high grade non-Hodgkin's lymphoma (NHL) and its clinical and prognostic significance. We performed immunohistochemical analysis of bcl-2 expression in tumoral tissue sections of 348 patients with high or intermediate grade NHL. These patients were uniformly treated with adriamycin, cyclophosphamide, vindesine, bleomycin, and prednisone (ACVBP) in the induction phase of the LNH87 protocol. Fifty eight cases were excluded due to inadequate staining. Of the 290 remaining patients, 131 (45%) disclosed homogeneous positivity (high bcl-2 expression) in virtually all tumor cells, whereas 65 (23%) were negative and 94 (32%) exhibited intermediate staining. High bcl-2 expression was more frequent in B-cell NHL (109 of 214, 51%) than in T-cell NHL (6 of 35, 17%) (P = .0004), and was heterogeneously distributed among the different histological subtypes. Further analysis was performed on the 151 patients with diffuse large B-cell lymphoma (centroblastic and immunoblastic) to assess the clinical significance and potential prognostic value of bcl-2 expression in the most frequent and homogeneous immunohistological subgroup. High bcl-2 expression, found in 44% of these patients (67 of 151), was more frequently associated with III-IV stage disease (P = .002). Reduced disease-free survival (DFS) (P < .01) and overall survival (P < .05) were demonstrated in the patients with high bcl-2 expression. Indeed, the 3-year estimates of DFS and overall survival were 60% and 61%, respectively (high bcl-2 expression) versus 82% and 78%, respectively (negative/intermediate bcl-2 expression). A multivariate regression analysis confirmed the independent effect of bcl-2 protein expression on DFS. Thus bcl-2 protein expression, as demonstrated in routinely paraffin-embedded tissue, appears to be predictive of poor DFS, in agreement with the role of bcl-2 in chemotherapy-induced apoptosis. It might be considered as a new independent biologic prognostic parameter, which, especially in diffuse large B-cell NHL, could aid in the identification of patient risk groups.

Adult↗

PubMed2006

The use of carbon dioxide wedged hepatic venography to identify the portal vein: comparison with direct catheter portography with iodinated contrast medium and analysis of predictive factors influencing level of opacification.

PURPOSE: This study was conducted to assess the value of wedged hepatic venography (WHV) with CO(2) as a contrast agent for identification of the portal venous system in patients with cirrhosis. Additionally, the predictive value of several parameters that potentially influence the level of portal vein opacification by CO(2) WHV was analyzed. MATERIALS AND METHODS: In 163 patients, CO(2) WHV was performed before transjugular intrahepatic portosystemic shunt creation to opacify and map the portal vein for subsequent targeting by intrahepatic puncture technique. Concordance between CO(2) WHV and direct catheter portography with iodinated contrast medium was assessed by analysis of sensitivity parameters. Additionally, analysis of factors potentially influencing the opacification of the portal vein with use of CO(2) WHV was assessed. RESULTS: CO(2) WHV was successfully performed in all 163 patients. In three patients (1.8%), CO(2) extravasation was noted, but without any clinical consequence. Sensitivity rates of CO(2) WHV for opacification of the right and left portal veins and the portal main trunk were 93.83% and 68.52%, respectively. Positive predictive factors (P < .05, Wilcoxon two-sample test) were high portosystemic gradient, spontaneous splenorenal shunt, esophageal varices, and reversed portal flow. One negative predictive factor was a patent umbilical vein. CONCLUSIONS: CO(2) WHV is safe, highly efficient, and reliable in the identification of the right and left portal veins. CO(2) WHV is clearly less effective in opacifying the entire portal main trunk. With use of CO(2) WHV, the portal venous system is most distinctly opacified in patients presenting with a high portosystemic gradient, a spontaneous splenorenal shunt, esophageal varices, and reversed portal flow.

Adult↗

PubMed2001

Alternative analysis of BOD removal in subsurface flow constructed wetlands employing Monod kinetics.

A new, mechanistic approach for design and analysis of subsurface flow (SSF) constructed wetlands is presented. The model is based on the assumption that the biological processes in wetlands, like other biological systems, exhibit Monod kinetics. A Monod approach fits well with observed wetland performance. It predicts first-order behaviour at low concentrations, that is, pollutant removal rates which increase with increasing pollutant concentration; and zero-order or saturated behaviour at high pollutant concentrations, that is, a maximum pollutant removal rate. A kinetic analysis of subsurface flow constructed wetlands exhibiting Monod kinetics reveals that loading rate, as well as the zero-order degradation rate constant, are essential parameters for efficient wetlands design for the removal of organic carbon. In particular, Monod kinetics enables the identification of an absolute maximum removal rate which is necessary to prevent undersizing in design. This is significant because it represents a theoretical upper bound on loading rate for wetlands design. The analysis is applied to wetlands data collected in North America by the US EPA in order to extract design criteria for BOD removal. It reveals that maximum loadings for SSF wetlands are at least 80 kg ha-1 d-1 for BOD. In addition, a new dimensionless performance efficiency parameter, omega, is presented as a more effective means of comparing wetland performance.

Biodegradation, Environmental↗

PubMed2003

Laser diffraction: A new tool for identification and studies of physiological effectors involved in aggregation-coagulation of the rubber particles from Hevea latex.

Latex coagulation is the main limiting factor of rubber yield in Hevea brasiliensis (rubber tree). Using laser diffraction, we set up and optimized a new method for monitoring the kinetics of rubber particle (RP) aggregation, a prerequisite for latex coagulation. In contrast to any previous method used, laser diffraction allows continuous monitoring changes in size of RP aggregates, thereby allowing characterization and quantification of the processes involved in latex coagulation. Using this technique, we confirm that RP aggregating factors are proteins compartmentalized within latex cell vacuoles (lutoids), which, especially at relatively acidic physiological pH, can induce formation of RP aggregates large enough to induce plugging of severed latex vessel extremities. Conversely, latex cytosol was found to harbor anti-aggregating proteins. Further, we were able to titrate the RP-aggregating efficiency of the intralutoidic serum and the anti-aggregating efficiency of the cytosol. Preliminary assays showed that these two parameters were correlated with the yield potential of the tested rubber clones. This method will allow identification and characterization of proteins involved in latex coagulation, hence in rubber yield. We suggest that laser diffraction could be used to monitor the kinetics and characterize the physiological processes involved in aggregation of any particles, organelles or cells.

Chemical Precipitation↗