High throughput parallel analysis of hundreds of patient samples for more than 100 mutations in multiple disease genes

As more mutations are identified in genes of known sequence, there is a crucial need in the areas of medical genetics and genome analysis for rapid, accurate and cost-effective methods of mutation detection. We have developed a multiplex allele-specific diagnostic assay (MASDA) for analysis of large numbers of samples (> 500) simultaneously for a large number of known mutations (> 100) in a single assay. MASDA utilizes oligonucleotide hybridization to interrogate DNA sequences. Multiplex DNA samples are immobilized on a solid support and a single hybridization is performed with a pool of allele-specific oligonucleotide (ASO) probes. Any probes complementary to specific mutations present in a given sample are in effect affinity purified from the pool by the target DNA. Sequence-specific band patterns (fingerprints), generated by chemical or enzymatic sequencing of the bound ASO(s), easily identify the specific mutation(s). Using this design, in a single diagnostic assay, we tested samples for 66 cystic fibrosis (CF) mutations, 14 beta-thalassemia mutations, two sickle cell anemia (SCA) mutations, three Tay-Sachs mutations, eight Gaucher mutations, four mutations in Canavan disease, four mutations in Fanconi anemia, and five mutations in BRCA1. Each mutation was correctly identified. Finally, in a blinded study of 106 of these mutations in > 500 patients, all mutations were properly identified. There were no false positives or false negatives. The MASDA assay is capable of detecting point mutations as well as small insertion or deletion mutations. This technology is amenable to automation and is suitable for immediate utilization for high-throughput genetic diagnostics in clinical and research laboratories.      

Arthus-type nephritis. II. Glomerular clearing system against poorly soluble and insoluble immune complexes

The uptake and transport of immune complexes (IC) in glomeruli were studied in Arthus-type nephritis induced by ferritin anti-ferritin IC. This experimental nephritis was transient in nature, forming electron dense aggregates and deposits in glomeruli, and was considered to be suitable for the analysis of the glomerular defence against immune complex injury. The IC were taken up and removed from the glomerular circulation first by polymorphonuclear leukocytes and later by macrophages. The IC in the glomerular capillary walls and mesangium were seen to shift slowly from the peripheral part of the glomeruli to the more central and juxtaglomerular area. It is speculated that the glomerular integrity is maintained from the immune complex induced tissue injury through the handling and removal of phlogogenic IC by the blood derived phagocytic system and intrinsic glomerular clearing system.     

Histologic transformation in extranodal non-Hodgkin's lymphoma

Histologic transformation in the course of non-Hodgkin's lymphoma (NHL) has been reported to occur in 18 to 30% of the cases. Less favorable prognosis in cases with initial low grade malignancy followed by emergence of high grade malignancy has been previously described. In the previous literature, the histologic transformation has been examined mostly in nodal NHL. In the present study, histologic transformation in the course was investigated on 20 cases with early extranodal NHL. All these 20 cases were diffuse lymphomas, and were composed of 7 cases with low grade malignancy and 13 cases with high grade malignancy. Histologic transformation was not observed in any of these cases. These findings indicate that the frequency of histologic transformation is much lower in extranodal NHL than in nodal NHL. The prognostic significance of these findings is also discussed.     

Immunoreactivity and receptor expression of insulinlike growth factor I and insulin in human adrenal tumors. An immunohistochemical study of 94 cases.

Using immunoperoxidase methods, 94 human adrenal tumors were examined for evidence of immunoreactivity and receptor expression of insulinlike growth factor I (IGF-I) and insulin. The frequency of IGF-I in adrenocortical carcinomas was significantly higher than that in adenomas of the adrenal glands. The adrenocortical carcinomas showed strong intensity of staining for IGF-I, IGF-I receptors, and insulin receptors. A significant correlation between immunoreactivity and receptor expression of both IGF-I and insulin was found only in the adrenocortical carcinomas. The adrenocortical adenomas with Cushing's syndrome and pheochromocytomas, more than adrenocortical adenomas with Conn's syndrome, also stained strongly for insulin receptors. Thus the IGF-I and insulin probably play a role in the growth of adrenocortical carcinoma tissues, possibly through autocrine mechanisms. The expression of insulin receptors in adrenocortical adenomas in the presence of Cushing's syndrome and pheochromocytomas may be associated with functions.     

A novel mis-sense mutation (G1381A) in the G6PD gene identified in a Chinese man

Objective　To detect new mutations among 29 glucose-6-phosphate dehydrogenase (G6PD) deficient individuals from Yunnan province. Methods　The nitroblue tetrazolium (NBT) method was used to screen G6PD deficient individuals. Mutation was identified by single strand conformation polymorphism (SSCP), amplification created restriction site (ACRS), amplification refractory mutation system (ARMS) and DNA sequencing. Results　Among 29 cases, 18 cases of G1388A, 1 case of C1004A, and 1 case of G1381A were identified. Nine cases remained to be defined. The G1381A mutation is a novel mis-sense mutation, with a substitution of threonine for alanine (A461T). The resultant G6PD had reduced enzymatic activity. In addition, G1381A caused a restriction site of Stu I to disappear, providing a rapid method for the detection of this mutation. Conclusion　A novel mis-sense mutation G1381A was found. This mutation results in a substitution of threonine for alanine, producing enzyme with reduced activity. The loss of the Stu I restriction site offers a rapid method for the detection of this mutation.     

Influence of popliteal vein thrombosis on subsequent ambulatory venous function measured by near-infrared spectroscopy

BACKGROUND: To determine the influence of the site affected by thrombi on the subsequent venous physiology, we examined patients with postthrombotic syndrome (PTS) with respect to ambulatory venous function using near-infrared spectroscopy (NIRS). METHODS: Fifty-one limbs of 45 patients, for whom more than 1 year had passed since an acute episode of deep vein thrombosis, were studied. Seventeen limbs were asymptomatic, 27 had mild symptoms (edema only), and 7 showed severe symptoms (skin changes). The mean duration of PTS was 8.2 years. All of the patients underwent a treadmill walking test with simultaneous NIRS. Deoxygenated hemoglobin was continuously measured during exercise. The ambulatory venous retention index (AVRI) obtained from the serial deoxygenated hemoglobin changes was calculated in each patient. The location of thrombi at the onset of deep vein thrombosis was identified by venography. RESULTS: The calculated AVRI was apparently related to the clinical symptoms of PTS. The limbs initially involved with popliteal vein thrombosis showed significantly higher AVRI values than those without popliteal vein thrombosis. CONCLUSIONS: The clinical severity of PTS is correlated well with the degree of venous retention during exercise. Initial involvement of the popliteal vein is an important factor determining subsequent venous hemodynamics in patients with PTS.     

3D TOF turbo MR angiography for intracranial arteries: phantom and clinical studies

This work investigated whether turbo magnetic resonance angiography (MRA) can replace conventional MRA in screening examination of intracranial arteries. A phantom was used to evaluate the effect of the zero-filling interpolation (ZFI) technique on spatial resolution and partial volume effect. Thirty-one consecutive patients underwent both turbo MRA with a slice thickness of 0.7 mm (data were measured as 1.33 mm sections) and conventional MRA with 1.0 mm sections. In the phantom studies, ZFI did not improve the spatial resolution, but the partial volume effect was somewhat reduced. In the clinical evaluation, turbo MRA showed better signal-to-noise and contrast-to-noise ratios of the intracranial major vessels than conventional MRA. The lesions included cerebral aneurysms less than 3 mm in diameter, occlusive vascular disease, arteriovenous malformations, and arteriovenous fistulas. These were all depicted on both turbo MRA and conventional MRA. Turbo MRA is a useful screening procedure because of its capability of delineating lesions in approximately half the usual imaging time. J. Magn. Reson. Imaging 1999;10:939-944.     

Effects of various lidocaine compounds on cuff pressure of a reinforced tracheal tube

Effects of various lidocaine compounds on cuff pressure of a tracheal tube were studied. Thirty reinforced tracheal tubes (Mallinckrodt Medical, Ireland) were divided into five groups and the cuffs were treated with normal saline, 2% lidocaine jelly, plain lubricant jelly, 4% lidocaine solution or 8% lidocaine pump spray. The cuff pressures of each tube was measured with 5, 10, 15, and 20 ml of air at the time of 0, 30, 60, 90, and 120 min after the treatment. The cuff pressures with 20 ml of air (P20) were compared among the groups. Thirty min after the treatment on the cuffs, P20 of the tubes with lidocaine spray significantly decreased than that of the control tubes with normal saline. In 2 of 10 tubes on which lidocaine had been sprayed, the cuffs were damaged 90 min after the treatment. Any jelly or solution on the cuffs did not influence the cuff pressure-volume relationship. We conclude that lidocaine pump spray should not be used as a lubricant on the cuff of a reinforced tracheal tube.     

Conservative management of a methicillin-resistantStaphylococcus aureus (MRSA)-infected aortobifemoral graft: Report of a case

A 63-year-old man was referred to our department for treatment of intermittent claudication in the right lower limb. The preoperative angiogram showed severe stenosis extending from the terminal aorta to the bilateral common femoral arteries, with occlusion of the right superficial femoral artery and the left popliteal artery. He underwent aortobifemoral bypass with thromboendarterectomy of the left common femoral artery, and right graft-popliteal artery bypass. The patient had an uneventful postoperative course; however, 14 days after the operation, a pulsatile mass suddenly appeared in the left groin. Emergency surgery revealed disruption of the left distal anastomosis of the aortobifemoral bypass and therefore, revision, in the form of graft-profunda femoris artery interposition with graft-superficial femoral artery bypass, was performed. Microscopic examination showed colonies of bacteria in the host artery adventitia adjacent to the anastomosis. Culture of the discharge from the right groin operative scar revealed methicillin-resistantStaphylococcus aureus (MRSA). The discharge resolved following the intravenous administration of vancomycin and the local application of vancomycin ointment. There were no operative complications other than the MRSA infection, and the patient was discharged 20 days after revision surgery. In the 14 months since the revision, all grafts have remained patent and there have been no further symptoms of graft infection.