Characterization of two new matrices for matrix-assisted laser desorption/ionization mass spectrometry

Three structurally related compounds, 4-hydroxy-33-methoxyphenylpyruvic acid (HMPPA), indole-3 pyruvic acid (IPA), and indole-3-glyoxylic acid have been evaluated as matrix-assisted laser desorption/ionization (MALDI) matrices. HMPPA and IPA were found to be effective matrices for MALDI-MS analysis of proteins and peptides and have been characterized in this work. HMPPA was found to be a particularly good matrix for the analysis of proteins and peptides because of its tolerance towards impurities and the resulting sensitivity in MALDI-MS experiments. Analysis of model proteins and peptides, including those in biological fluid, are demonstrated.

Use of a nitrocellulose film substrate in matrix-assisted laser desorption/ionization mass spectrometry for DNA mapping and screening

A nitrocellulose film is used as a substrate in matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) studies of DNA. PCR products and DNA fragment digests obtained from biochemical procedures can be analyzed with the use of a nitrocellulose substrate in MALDI MS whereas no signal is observed with the use of a stainless steel substrate. In this method, on-probe purification allows for effective elimination of the interfering effects of salts, buffers, and other contaminants that are usually present in DNA samples, which serve as important limiting factors in the DNA molecular ion yield in the MALDI process. The use of the nitrocellulose film substrate also appears to improve the shot-to-shot and sample-to-sample reproducibility of the ion yield due to the more homogeneous coverage of matrix/analyte over the sample surface. With the use of the nitrocellulose substrate, DNA fragments of up to 622 base pairs in complex mixtures provide mass spectra with minimal sample purification. Although only species corresponding to single-stranded DNA were detected, a mass calibration scheme was established allowing an accuracy of within one base pair for fragments of < 250 bp under the experimental conditions. Despite the low mass resolution of the spectra obtained, the method has been successfully used for rapid DNA screening for sample disease genes and PCR products.

[Correlation study of allelic gene deletion of nm23-H1 and human colorectal carcinoma metastasis]

In recent years, a tumor suppressor gene nm23 has been found to be associated with decreased tumor metastatic potential. Allelic deletion, mutation and low expression of this gene has been correlated with tumor metastatic potential in a number of tumors. There are two known isotypes of human nm23 gene, named nm23-H1 and nm23-H2. We examined DNA from 23 cases of colorectal carcinomas and their corresponding normal mucosa using Southern blot hybridization with nm23-H1 cDNA probe. Five cases with allelic deletion of nm23-H1 gene were found, with allelic deletion rate of 57. 1% (4/7) in cases with metastasis to lymph node, liver or other organs, and 6.2% (1/16) in cases without metastases (P < 0.005). There is no correlation between allelic deletion and tumor size, location or differentiation. This result indicates that nm23-H1 gene plays an important role in the metastasis of colorectal carcinoma.

Experimental renal artery stenosis and angioplasty. The mechanism of the angioplasty

The mechanism of percutaneous transluminal renal angioplasty (PTRA) was studied in 18 dogs. The dogs were divided into two groups. Seven dogs were in the early group and eleven were within 1-3 weeks after PTRA. A 4/0 resorbable chronic catgut was used to ligate subtotally the renal artery to create fibromuscular dysplasia. PTRA was performed after renal artery stenosis for 6-8 weeks. The changes of ultrastructure of renal artery were studied. A contrary orientation balance hypothesis was proposed to explain the mechanism of PTRA.

Body composition and bone mineral density in untreated and treated patients with celiac disease

Body composition and bone mineral density (BMD) were studied by X-ray absorptiometry in 20 untreated and 12 treated women with celiac disease, as well as in 85 age-matched control women. Untreated patients had a significantly lower body weight, fat mass, lean tissue mass and BMD at the lumbar spine and total skeleton compared to controls (p < 0.001 for all parameters). Treated patients had also a significantly lower body weight (p < 0.01) fat mass (p < 0.05) and bone mineral density at lumbar spine and total skeleton (p < 0.05) compared with controls, but lean tissue mass was not diminished. However, treated patients had a significantly higher body weight, fat mass and BMD of the total skeleton compared with untreated celiac patients (p < 0.01 for all parameters). Serum alkaline phosphatase levels were increased in untreated patients but serum 250HD was normal. In conclusion, celiac disease causes a global and almost universal reduction of fat mass and BMD. The results of this cross-sectional study suggest that osteopenia does not seem to be completely restored by adequate treatment. Alteration of vitamin D metabolism was not the cause of osteopenia in the majority of patients.

HPRS-103 (exogenous avian leukosis virus, subgroup J) has an env gene related to those of endogenous elements EAV-0 and E51 and an E element found previously only in sarcoma viruses

The avian leukosis and sarcoma virus (ALSV) group comprises eight subgroups based on envelope properties. HPRS-103, an exogenous retrovirus recently isolated from meat-type chicken lines, is similar to the viruses of these subgroups in group antigen but differs from them in envelope properties and has been assigned to a new subgroup, J. HPRS-103 has a wide host range in birds, and unlike other nontransforming ALSVs which cause late-onset B-cell lymphomas, HPRS-103 causes late-onset myelocytomas. Analysis of the sequence of an infectious clone of the complete proviral genome indicates that HPRS-103 is a multiple recombinant of at least five ALSV sequences and one EAV (endogenous avian retroviral) sequence. The HPRS-103 env is most closely related to the env gene of the defective EAV-E51 but divergent from those of other ALSV subgroups. Probing of restriction digests of line 0 chicken genomic DNA has identified a novel group of endogenous sequences (EAV-HP) homologous to that of the HPRS-103 env gene but different from sequences homologous to EAV and E51. Unlike other replication-competent nontransforming ALSVs, HPRS-103 has an E element in its 3' noncoding region, as found in many transforming ALSVs. A deletion found in the HPRS-103 U3 EFII enhancer factor-binding site is also found in all replication-defective transforming ALSVs (including MC29, which causes rapid-onset myelocytomas).

Faecal alpha 1-antitrypsin concentration in the diagnosis and management of patients with pouchitis

OBJECTIVE

To investigate the role of faecal alpha 1-antitrypsin concentration in the diagnosis and management of patients with ileal pouch-anal anastomosis.

DESIGN

Prospective study.

METHODS

Fifty-two measurements of faecal alpha 1-antitrypsin concentration were taken from 33 patients operated on for ulcerative colitis.

RESULTS

Patients with active pouchitis (44.4 +/- 7.1 mg%) had a three-fold higher mean faecal alpha 1-antitrypsin concentration than patients in remission (13.7 +/- 1.3 mg%; P < 0.0001), than patients who had never had pouchitis (14.4 +/- 2.3 mg%; P < 0.003) and than patients with incontinent ileostomies (12.7 +/- 1.3 mg%; P < 0.004). Faecal alpha 1-antitrypsin measurements were 80% sensitive and 97% specific for active pouchitis. A significant positive correlation between the pouchitis disease activity index and faecal protein loss was observed (r = 0.702; P < 0.0001). The correlations between protein loss and other parameters were weaker (protein loss versus clinical score, r = 0.309; versus endoscopic score, r = 0.583; and versus histologic score, r = 0.558).

CONCLUSION

Faecal alpha 1-antitrypsin concentration is a good indicator of the degree of intestinal inflammation in pouchitis and may be useful as a quantitative index of disease activity in prospective studies.

Sequence of host-range determinants in the env gene of a full-length, infectious proviral clone of exogenous avian leukosis virus HPRS-103 confirms that it represents a new subgroup (designated J)

A genomic DNA library was constructed, in a bacteriophage lambda vector, from line 0 chick embryo fibroblasts (CEFs) infected with HPRS-103, an exogenous avian leukosis virus (ALV; envelope subgroup J) recently isolated from meat-type chickens. The library was screened at high stringency using a full length RAV-1 (subgroup A) proviral probe. From 10(6) plaques, two clones which hybridized strongly to the RAV-1 probe were isolated; one contained a full-length copy of the proviral genome of HPRS-103 and the other contained a copy lacking the 5'-long terminal repeat (LTR) and part of gag. The relative strength of hybridization of RAV-1 and HPRS-103 clones, to RAV-1 probes representing different parts of the proviral genome, indicated that the gag and pol genes of HPRS-103 share a high level of identity with those of RAV-1 but that the env gene and the LTRs are considerably less well conserved. Infectious virus was recovered from CEFs transfected with the full-length clone, as detected by ELISA. The recovered virus appeared to be identical to HPRS-103 by electron microscopy and by Southern blotting of proviral DNA. The recovered virus was shown to be of the same subgroup as HPRS-103 by serum neutralization and receptor interference assays. Sequence analysis of the env gene of HPRS-103 shows that it differs considerably from the env genes of other ALV subgroups, particularly in the host range determinants, consistent with the finding that HPRS-103 represents a new subgroup (designated J).

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.