Rapid screening of genetic polymorphisms using buccal cell DNA with detection by matrix-assisted laser desorption/ionization mass spectrometry

A new approach is developed for the rapid and cost-effective detection of human genetic polymorphisms based on matrix-assisted laser description/ionization mass spectrometric (MALDI MS) detection using a nitrocellulose film substrate. This method employs polymerase chain reaction (PCR) amplification using DNA extracted from buccal cells as templates, followed by direct digestion with restriction enzymes and subsequent analysis by MALDI MS. The extraction of DNA from buccal cells provides a rapid and convenient means for sampling PCR-based diagnostic analysis. The amount of DNA was sufficient as the template for both normal PCR amplifications, and amplifications involving the use of mismatched primers and multiple primers. The MALDI MS methodology has been successfully used for the analysis of such PCR products where restriction fragments generated directly in PCR reactions have been used for detection of carbonic anhydrase and cystic fibrosis transmembrane conductance regulator as model genes. The detection of genetic polymorphisms following routine biological and clinical procedures with the MALDI MS method is demonstrated. The results from MALDI MS analysis are shown to be comparable to those obtained from gel electrophoresis but the MALDI MS method is several orders of magnitude faster than gel electrophoretic techniques. The method described herein should also be readily extended to other areas involving DNA screening and testing.

Matrix-assisted laser desorption/ionization using an active perfluorosulfonated ionomer film substrate

The use of an active Nafion substrate is shown to enhance the performance of MALDI MS. The use of a Nafion substrate with certain matrices can significantly enhance the signals obtained over those observed with a stainless steel probe substrate. Analytes can often be observed with the use of the Nafion substrate that cannot be easily observed with the standard MALDI procedure, and usually a much wider range of peaks can be observed using MALDI from the Nafion substrate than with any single matrix on a stainless steel substrate. This enhancement of signal from the Nafion substrate is observed only with the sequential deposition of the sample and the matrix onto the Nafion film. If the analyte and matrix are premixed, then the effect is not observed. The use of the Nafion substrate has been shown to be particularly effective in analyzing real biological mixtures without prepurification. This has been demonstrated for various samples including the analysis of the products of chemical digests of proteins, protein profiling in milk and egg white samples, cell lysate analysis, and oligonucleotide detection.

A study of optimal configuration and control of a multi-chamber balloon for intraaortic balloon pumping

Balloon configuration and control scheme are important for the optimization of assistance of the failing heart with an intraaortic balloon pumping device. In this work, the configuration of a multi-chamber balloon and control schemes have been investigated by using a hemodynamic model and computer simulation methods. Following the simulation study, physical testing and animal experiments were performed to demonstrate the simulation results. Results show that the optimal configuration and controlled multi-chamber balloon can provide better assistance to the failing heart. Based on the simulation and experimental results, it was found that the shape of the rear chamber of a multi-chamber balloon is critical. The optimal control scheme was to inflate the rear chamber first and deflate it last.

Matrix-assisted laser desorption/ionization mass spectrometry of restriction enzyme-digested plasmid DNA using an active Nafion substrate

Matrix-assisted laser desorption/ionization using a 3-hydroxypicolinic acid matrix from an active Nafion substrate has been used for detection of restriction enzyme-digested double-stranded plasmid DNA using time-of-flight mass spectrometry. DNA strands of up to 267 base pairs were detected with minimal sample purification, although only as species corresponding to single-stranded DNA.

A simulation study of external counterpulsation

To study the haemodynamic effect of external counterpulsation, a computer model has been extended based on our previous work. Using this model, computer simulations have been performed on following aspects: the relationship between blood flow distributions and the control scheme; counterpulsation with and without buttock balloons; effects of duration and time intervals for sequential pulsing; and the potential to use a performance index for the optimal control of this assist device to the failing heart. The results indicate that effective assistance can be achieved by a proper setting of the control scheme. The results also show that this device is effective to improve the circulation status of other organs in addition to the heart. Simulation results agree well with the clinical data.

Ultrastructural observations of the anterior chamber angle tissues in congenital glaucoma

Eighteen trabeculectomy specimens of congenital glaucoma were examined by light and transmission electron microscopy. The results showed that the primary anomalies in congenital glaucoma included the developmental defects of trabecular meshwork, excessive collagen fibrils in the trabecular matrix, shifting forward of ciliary muscle fibres and persistent mesenchymal tissues in the anterior-chamber angle. The authors also pointed out the importance of the secondary lesions of the trabecular meshwork in the pathogenesis of congenital glaucoma.

Chromosome instability in lymphocytes from patients with celiac disease

Cytogenetic studies were performed in celiac disease (CD) patients to determine if the presence of chromosome instability is related to the predisposition to cancer. Chromosome aberrations (CA) and sister chromatid exchange (SCE) frequencies in peripheral blood lymphocyte cultures from untreated CD patients and healthy controls were analyzed. Patients showed aberrations in 23% of cells, while only 3% were detected in the control group (p < 0.0001). The mean frequencies of gaps, breaks and total CA were found to be higher in CD patients compared to controls (p < 0.0001). Breakpoint distribution was nonrandom among chromosomes from celiac patients (p = 0.01), but not among controls (p = 0.04). The frequency of SCE/cell showed a mean value of 6.9 +/- 0.6 in CD patients and 7.3 +/- 0.2 in controls. No statistical differences were found. Breakpoints involved in CD patients presented a strong coincidence with the location of fragile sites (78.6%) and sites of cancer chromosome rearrangements (57.1%), most of them (75%) associated with malignant non-Hodgkin lymphomas. These results suggest that CD is a condition with increased chromosome instability characterized by a high level of CA and normal SCE frequencies, probably related to the increased incidence of cancer.

Cardiovascular responses to external counterpulsation: a computer simulation

A mathematical model of the human cardiovascular system is presented which includes a simulation of cardiac assistance by external counterpulsation. The model was established to study the effects of external counterpulsation on cardiovascular haemodynamics. The closed simulation includes both the left and the right heart and the pulmonary circulation. The model is able to provide data for the behaviour of the system under varying modes of assistance. Our results suggest that control of external counterpulsation is more difficult than control of the intra-aortic balloon pump and requires regulation of a larger number of variables. The results also suggest that a tradeoff exists between improved oxygen delivery to the heart and reduction in the oxygen consumption of the myocardium, an observation similar to that reported for the intra-aortic balloon pump.

Increased rDNA transcriptional activity in celiac disease

The activity of nucleolar organizer regions (NORs) in chromosomes of peripheral blood lymphocyte cultures from 20 healthy subjects and 32 patients with celiac disease (CD) (nine untreated patients, nine treated but with dietary lapses, and 14 treated with gluten-free diet (GFD) and normal small bowel histology) was studied. Furthermore, three female patients diagnosed with small bowel non-Hodgkin's lymphoma (NHL) complicating CD were studied. Silver (Ag)-staining technique was used to visualize positive NORs. In each individual, 20 metaphases were analyzed to determine the number of NORs per cell. The average of Ag-NOR+ per cell, expressed as mean +/- SD, was found to be higher in the CD group (6.62 +/- 0.65) compared with controls (5.70 +/- 0.81) (p less than 0.001). This increase was evident in both groups of chromosomes analyzed (D and G). No differences were found among the three groups, but all of them were found to be statistically different compared to controls (p less than 0.001). The NHL complicating CD patients showed a statistically increased frequency of Ag-NORs (7.20 +/- 0.39) with respect to CD patients (p less than 0.02) and controls (p less than 0.001). These findings show an increase of the transcriptional activity of rDNA in CD that could be related to the high incidence of malignancy in this pathology. Longitudinal studies of CD patients should be performed to confirm this evidence.

Celiac sprue after surgery of the upper gastrointestinal tract. Report of 10 patients with special attention to diagnosis, clinical behavior, and follow-up

The clinical onset of celiac sprue (CS) may be precipitated by upper digestive tract surgery. We report a series of 10 patients who developed CS after diverse types of peptic ulcer surgery. Six were male and 4 female. Gastrectomy with Billroth II anastomosis was performed in 5 patients, truncal vagotomy and pyloroplasty in 2, parietal cell vagotomy and pyloroplasty in 1, and vagotomy with gastrojejunal anastomosis in 2. We found that eight patients had had previous symptoms that suggested CS. Symptoms occurred early in the postoperative period. Severe diarrhea and striking weight loss were the most prominent clinical findings. The response to gluten-free diet was independent of the type of surgical procedure performed and was similar to that observed in the general celiac population.

Keshan disease-an endemic cardiomyopathy in China

Keshan disease, an endemic cardiomyopathy in China, was prevalent in rural areas located in a long belt region where the selenium content was low in foods. Intervention studies with well controlled subjects revealed a prophylactic effect of sodium selenite. Multifocal necrosis and fibrous replacement of the myocardium characterized the histopathological features and myocytolysis was present in most cases. Ultrastructural observations on twelve postmortem cases revealed remarkable changes in many organelles of which mitochondria appeared to be most important in the development of myocardial lesions. Three kinds of specific granules, which have not been found in other reports on cardiomyopathies, were represented and other factors which might also contribute to the aetiology are discussed.

Pregnancy complicated by heroin addiction

During a 5-year time span, 118 addicted women gave birth to viable infants. These patients were subject to an increased incidence of complicating medical problems as well as many obstetric problems leading to maternal or fetal risk. The obstetrician should be aware of the possibility of addiction and its effects on pregnancy, and when possible, appropriate management should be initiated. Intensive care of the neonate must be begun as soon as possible.