Membrane protein structure: the contribution and potential of novel solid state NMR approaches.

Alternative methods for describing molecular detail for large integral membrane proteins are required in the absence of routine crystallographic approaches. Novel solid state NMR methods, devised for the study of large molecular assemblies, are now finding applications in biological systems, including integral membrane proteins. Wild-type and genetically engineered proteins can be investigated and detailed information about side chains, prosthetic groups, ligands (e.

Correlation between high-field T2-weighted MR imaging and histology of ischemic lesions in gerbil brain.

Global forebrain ischemia in the Mongolian gerbil is a common animal model for use in stroke research. We produced lesions of graded severity in gerbil brains (after prescreening by MR imaging) by performing 6-minute bilateral carotid artery occlusions while monitoring pericranial temperature with a temporalis muscle thermocouple probe and maintaining the temperature at 32 degrees C, 36 degrees C, or 40 degrees C. Lesion severity was scored 4 days after occlusion from findings on spin-echo images acquired at 7 T and from histologic scores.

The conformations of a functional spin-labeled derivative of gastric H/K-ATPase investigated by EPR spectroscopy.

A spin-labeled derivative of porcine gastric H/K-ATPase with high ATP hydrolyzing activity (77 mumol of Pi/(mg.h)) has been prepared. Over 65% of initial ATPase activity (115 mumol of Pi/(mg.

Genetic diversity in the non-structural gene of parvovirus B19 detected by single-stranded conformational polymorphism assay (SSCP) and partial nucleotide sequencing.

A homologous region in the parvovirus B19 non-structural gene (B19 nt 1399-1682) was examined in 50 samples from patients with a wide variety of B19-related disease from various countries by PCR amplification, single-stranded conformational polymorphism (SSCP) assay and nucleotide sequencing. Five SSCP types were confirmed by nucleotide sequence analysis. Of a total of 6 mutations, all were silent.

Image directed proton spectroscopy of gerbil brain at 7 tesla.

Image directed localized 1H NMR spectra were obtained at 7 T (300 MHz) from cubic volumes of less than 40 microL in the gerbil brain. Signals from cerebral metabolites commonly detected in other rodent species were easily assigned, and high resolution spectroscopy (360 MHz) of aqueous brain extracts assisted the tentative identification of partially overlapping resonances from lower concentration compounds like alanine, lysine, gamma-aminobutyrate, valine, leucine and isoleucine. Weak coupling at 7 T was manifest in the resolution of signals from the gamma-CH2 groups of glutamine and glutamate.

Modification of an HLA-B PCR-SSOP typing system leading to improved allele determination.

Modifications have been introduced to a previously reported HLA-B PCR-SSOP typing system. This has enabled further definition of alleles, determination of the probe pattern of some alleles not previously examined and identification of patterns of possible new alleles. However there are still some alleles that cannot be differentiated and there are several alleles which when present as a homozygote have the same pattern as in combination with another allele.

Alternate pre-mRNA processing pathways in the production of membrane IgM heavy chains in holostean fish.

A single gene encodes two forms of the IgM heavy chain (mu) in vertebrates: one (microseconds) present in serum as secreted IgM and the other (microns) as the antigen receptor form of IgM present on the B-lymphocyte membrane. The mRNAs encoding microseconds and microns are derived from a single primary transcript by alternate pathways of RNA processing. In all vertebrates so far examined, with the exception of teleosts, microns mRNA is produced by splicing the transmembrane (TM) encoding exon 1 into a cryptic donor site near the 3' end of the C mu 4 exon.

cDNA sequences and organization of IgM heavy chain genes in two holostean fish.

Immunoglobulin M heavy chain (mu) sequences of two holostean fish, the bowfin, Amia calva, and the longnose gar, Lepisosteus osseus, were amplified from spleen mRNA by RACE-PCR, cloned, and sequenced. Each mu chain showed the conserved four constant domain structure typical of a secreted mu chain. Southern blot analyses with specific heavy chain variable (VH) and constant (CH) region probes suggest that both fish possess an IgH locus that resembles that of the teleosts, amphibians, and mammals in its organization.

An Ig heavy chain enhancer of the channel catfish Ictalurus punctatus: evolutionary conservation of function but not structure.

The teleost fishes are among the earliest evolutionary lineages to have an Ig heavy chain (IgH) locus whose organization approximates that of mammals. To understand transcriptional control of the IgH locus in a teleost fish and to gain insight into the evolution of the control elements, the enhancer activity in the IgH locus of the channel catfish, Ictalurus punctatus, was investigated. Segments of the locus extending from upstream of the proximal JH gene to 2.

One gene encodes the heavy chains for three different forms of IgY in the duck.

IgY, the major Ab of the duck (Anas platyrhynchos), exists in two secreted forms and a transmembrane (TM) form. To investigate the genetic relationships of the multiple IgY we cloned the gene encoding the IgY (upsilon) heavy chains. The heavy chain of the smaller (5.

cDNA sequence and organization of the immunoglobulin light chain gene of the duck, Anas platyrhynchos.

A cDNA was cloned which encoded an immunoglobulin (Ig) light (L) chain of the White Pekin duck. The organization of the variable (V) and constant (C) domains was analyzed by genomic Southern blotting. The duck L chain gene has a similar chromosomal organization to that of the chicken, with a single lambda-like C region and multiple VL, hybridizing elements.

Transfusion of one HLA-DR antigen-matched blood to potential recipients of a renal allograft.

Patients awaiting a renal transplant were given 1 HLA-DR antigen-matched blood in order to compare the sensitization and graft outcome of these patients with those of control patients, who had been given random blood before transplantation. No differences in sensitization, measured by the formation of HLA antibodies, or in graft survival were found between the 2 groups. However, the incidence of rejection episodes was significantly reduced in the patients who received blood matched for 1 HLA-DR antigen compared with the patients who received random blood.

Alopecia Universalis in a Horse.

Abstract- Alopecia universalis was diagnosed in a 3-year-old brown Percheron mare. Clinical and histo-pathologic findings in this previously unreported condition in the horse are described.

Is the phenotypic combination A1B8Cw7DR3 a marker for male longevity?

Objective: To study whether individual Human Leucocyte Antigens (HLA) at the HLA 1 or 11 loci or the phenotypic combination A1B8Cw7DR3 were associated with longevity.

Design: Direct comparison of the > 90-year-old subjects with a control group.

Setting: Northern Ireland population with little migratory mobility.

Lesions caused by natural infection with Streptococcus suis type 9 in weaned pigs.

In this paper we report on the spectrum and frequency of lesions observed in a prospective study of naturally occurring infections with Streptococcus suis type 9 (SS-9) in weaned pigs. SS-9 produced arthritis, meningitis, interstitial pneumonia, and endocarditis in 100%, 91%, 73%, and 42%, respectively, of pigs dying from the disease. The lesions were similar to those caused by S.

Identification of MHC--molecular biology.

Many of the molecular methods currently in use in the histocompatibility laboratory have been described. The use of a specific technique will depend on the laboratory's requirements. Obviously those laboratories involved in cadaver transplantation will use techniques suitable for single sample analysis which give results within six hours.

TAP1 and TAP2 polymorphism in multiple sclerosis patients.

The frequency of TAP1 and TAP2 gene polymorphisms in MS patients was compared with that of a normal population. A significant increase in TAP2-379-VAL homozygosity and TAP2-565-ALA homozygosity was found in HLA-DRB1*1501-DQB1*0602-negative patients.

Tick-borne infections.

Preview Is it because people are traveling more often or to more remote locations or because exposure to ticks is becoming more common? Whatever the reason, diseases spread by tick bites are being reported more often than in the past. Some of these, such as Rocky Mountain spotted fever and ehrlichiosis, can have very severe, even fatal, consequences. Dr Middleton describes findings that suggest tick-borne disease and summarizes effective treatment and prevention methods.

Tick-borne infections. What starts as a tiny bite may have a serious outcome.

Tick-borne illnesses are being reported increasingly often. Unlike Lyme disease, which tends to be indolent, Rocky Mountain spotted fever and ehrlichiosis can kill and so must be recognized and treated promptly. These diseases require clinical diagnosis, because laboratory confirmation with antibody tests takes too long.

Effects of proligestone and megestrol on plasma adrenocorticotrophic hormone, insulin and insulin-like growth factor-1 concentrations in cats.

This paper reports changes in adrenocorticotrophic hormone (ACTH), insulin and insulin-like growth factor-1 (IGF-1) concentrations in cats from a previously published study. The cats were given oral megestrol acetate (MA, 5 mg once daily for 14 days), subcutaneous proligestone (PRG, 100 mg on two occasions one week apart) or subcutaneous saline (1 ml as for PRG). In the cats given saline (n = 6), basal ACTH, insulin and IGF-1 did not change significantly throughout the following seven weeks.