Transplanting teeth successfully: autografts and allografts that work

This article suggests tooth transplantation as an alternative to other restorative options. The 10-year success rates for autografts--teeth moved from one location to another in a patient's mouth--range from 60 percent to 95 percent. Allografts, teeth moved from one person to another, are less successful. The authors report on one case of each type of transplant.

Quantitative analysis of phosphorothioate oligonucleotides in biological fluids using direct injection fast anion-exchange chromatography and capillary gel electrophoresis

The analysis of antisense phosphorothioate DNA (SODN) in human plasma via direct injection using anion-exchange high-performance liquid chromatography (AE-HPLC) is presented. The method relies on the ability to selectively extract phosphorothioate DNA from undigested serum, plasma and urine on anion-exchange resins. The automated HPLC method can analyze a sample every 5 min with a limit of detection of 50 ng/ml (ppb). The DNA was collected, desalted and analyzed by capillary gel electrophoresis. Due to the high resolving power of this technique, a qualitative assessment of enzymatic degradation of the antisense oligonucleotide can be made.

Combined treatment with terbutaline and aminophylline inhibits experimental amyloidosis in mice

OBJECTIVE

To investigate the effects of drugs known to elevate adenosine 3':5'-cyclic monophosphate (cAMP) on experimental amyloidosis.

METHODS

A beta 2-agonist, terbutaline, and a phosphodiesterase inhibitor, aminophylline, were administered in combination in a mouse model of amyloidosis induced by inflammatory stimulation with silver nitrate. Amyloidosis was quantitated by radioimmunoassay for splenic amyloid A (AA) protein.

RESULTS

At the doses selected, aminophylline/terbutaline inhibited splenic amyloid deposition more potently than did colchicine, a known inhibitor of amyloidosis.

CONCLUSION

Drugs known to elevate cAMP inhibit experimental mouse AA amyloidosis.

The epidemiology of AL and AA amyloidosis

The limited available epidemiological information on AL amyloidosis suggests that there may be differences between population-based studies and case series data with respect to variables such as age and racial patterns. Much more work in this area is required before specific aetiologic hypotheses can be tested. Most available data to approximate the epidemiology of AA amyloidosis are derived from autopsies. Most patients with AA amyloidosis die from causes other than amyloidosis, therefore mortality data based on death certificates is of limited value in AA amyloidosis. Case ascertainment in autopsy studies may be difficult due to the frequent lack of adequate histological controls. Establishment of registries for both AL and AA amyloidosis would facilitate epidemiological research in these disorders.

Nitric oxide regulates spike frequency accommodation in nodose neurons of the rabbit

A Ca(2+)-dependent slow spike after hyperpolarization (AHPslow) is present in about 35% of the neurons in the nodose ganglion. Although the AHPslow profoundly affects spike frequency accommodation of these neurons, the mechanisms that control the generation and the duration of the AHPslow are unclarified. N omega-Nitro-L-arginine methyl ester (L-NAME; 10 microM), a specific inhibitor of nitric oxide synthase (NOS), reduced the AHPslow by more than 92%. The L-NAME block of the AHPslow was antagonized by application of 50 microM S-nitroso-N-acetylpenicillamine (SNAP), a nitric oxide donor. The fast, Ca(2+)-dependent, spike after hyperpolarization preceding the AHPslow and the elevation of intracellular Ca2+ accompanying the AHPslow were unaffected by L-NAME treatment. These findings indicate that products of NOS activity might directly or indirectly activate the AHPslow K+ channels at a step beyond Ca2+ influx or intracellular Ca2+ mobilization.

Orthotopic liver transplantation for familial amyloidotic polyneuropathy

Orthotopic liver transplantation for inborn errors of metabolism has become a standard indication for transplantation in pediatric and adult patients with alpha-1 antitrypsin deficiency, Wilson's disease and tyrosinemia, amongst several less common diseases. Familial amyloidotic polyneuropathy (FAP) is a rare autosomal dominant disease whose metabolic origin lies in an abnormal protein synthesized primarily in the liver. FAP, also discussed as the autosomal dominant form of amyloidosis, is characterized as a hereditary form of amyloidosis. It is the rarest form of amyloidosis affecting kindreds of specific ethnic backgrounds. The true incidence of this disease in the United States is not known. The mutant protein, called transthyretin or prealbumin, forms amyloid fibrils which accumulate in vital tissues ultimately leading to the patient's death. Liver transplantation for this inherited disease leads to the production of normal transthyretin protein. This theoretically should arrest the disease process. The first 5 patients in the United States with FAP who have undergone transplantation are presented.

Proteins of the systemic amyloidoses

Significant advances were made this year in the understanding of serum amyloid A isotypes and in the definition of different amyloid light-chain proteins. Increasing numbers of hereditary amyloid-related transthyretin mutations have been reported (more than 30 to date). Two new hereditary amyloid proteins in several different kinships have appeared, ie, fibrinogen A alpha and lysozyme, each with a single point mutation. Both were found in patients with non-neurogenic hereditary amyloidosis with severe nephropathy. In islet amyloid polypeptide, the amyloid of adult-onset diabetes, the amino-acid sequence Ala-Ile-Leu-Ser at positions 25 to 28 appears to be critical for fibrillogenesis.

Clinical aspects of amyloidosis, including related proteins and central nervous system amyloid

In the beta/A4 protein of Alzheimer's disease, on chromosome 21, three mutations at the same locus have been described (Val 717 Ile, Val 171 Phe, and Val 171 Gly). The heterogeneity of the disease was indicated in individuals with mutations involving chromosomes 19 and 14 as well. beta Protein has also been demonstrated in the rimmed vacuoles of inclusion-body myositis. Therapeutic advances include orthotopic liver transplantation to remove the site of synthesis of the mutant transthyretin molecule. Clinical manifestations of the various forms of amyloidosis involve virtually every system in the body; the breadth of the curious series of proteins called amyloid has been extended considerably in the past year.

DNA sequencing by capillary electrophoresis: use of a two-laser-two-window intensified diode array detection system

This paper presents the principles of an instrument designed for DNA sequencing using the standard four-dye-labeled primer approach. The method is based on capillary electrophoresis with laser-induced fluorescence and an intensified diode array detector. An important goal of the instrument design has been a detection system that possesses high sensitivity and high spectral resolution. Based on an analysis of the spectral characteristics of the four standard dye-labeled primers, FAM, JOE, ROX, and TAMRA, the strategy has been to use a two-laser-two-window approach, in which a 488-nm argon ion laser illuminates one window, followed by a 543-nm helium-neon laser illuminating the second window. The two-window approach has no moving parts and permits continuous illumination. Spectral resolution is provided by a grating spectrograph and a cooled intensified diode array. The estimated limit of detection for the standard four dye-labeled primers was found to be in the sample concentration range of 1 x 10(-12) M. To achieve these low levels, complete free-radical polymerization of polyacrylamide has been found to be necessary in order to reduce background noise. In addition, reduction in background noise was accomplished by continual purging of the anodic reservoir in order to prevent electrolysis products from entering the capillary. Separation of DNA sequencing reaction products is demonstrated on a 9% T linear polyacrylamide column.

Localized amyloidosis of the larynx: evidence for light chain composition

We report the biochemical characterization of amyloid fibrils from a patient with localized amyloidosis of the epiglottis and larynx. Biopsy specimens showed amorphous material consistent with amyloid deposits with a plasmacytic infiltrate. Both plasma cells and amyloid deposits stained positively by immunohistochemistry for kappa light chains. Amyloid fibrils were isolated. The major constituent resolved as a 13 kd band was sequenced and found to be consistent with a kappa 1 light chain. A tryptic digest was carried out and 3 tryptic peptides were sequenced defining the first 45 residues of the protein and residues 110 through 119. Four amino acid substitutions were found, 3 of which have not been described previously. This study defines the immunoglobulin origin of amyloid deposits in localized amyloidosis. The benign nature of localized amyloidosis suggests that a localized clone of plasma cells producing an amyloidogenic light chain may represent the pathogenetic mechanism of this disease, which appears to be a form of plasma cell dyscrasia.

Separation of DNA fragments by capillary electrophoresis using replaceable linear polyacrylamide matrices

The use of low percent (1.5-6% T) replaceable linear polyacrylamide (LPA) network matrices for rapid separation of double-stranded DNA fragments was explored. Separations of fragments ranging from 20 to 23,000 base pairs were readily achieved. Typically, 4 x 10(6) theoretical plates/m were obtained in less than 30 min. Short separation times under 2 min were also possible, using the DNA intercalating dye, ethidium bromide, along with high electric fields. The high resolving power of linear polyacrylamide was demonstrated in the separation of two fragments which differ by a single base pair (123/124 base pairs) using 6% T LPA and ethidium bromide intercalation. This LPA composition allowed for the possible single base-pair resolution of dsDNA fragments up to 300 base pairs in length. Several concentrations of the linear polyacrylamide for different ranges of fragment lengths have been employed. In addition, replaceable LPA offers the advantage of a fresh separation matrix for each run, thus overcoming column stability problems and minimizing needs for sample cleanup. Electro-osmotic flow was substantially reduced using stable capillary coatings, which were required for obtaining high efficiencies and good reproducibility.

Quantitative analysis of phosphorothioate oligonucleotides in biological fluids using fast anion-exchange chromatography

Phosphorothioate oligonucleotides are potentially useful as anti-viral drugs. Classical DNA extraction methods are not as effective on short single-stranded DNA as with longer double-stranced chains. The classical method of phenol-chloroform extraction followed by ethanol precipitation is difficult to quantify, thus monitoring of the pharmacological disposition of these compounds is subject to error. A method has been devised and validated for extraction and analysis of modified oligonucleotides from biological fluids such as urine and serum based on protein kinase digestion and phenol-chloroform extraction. Due to the high native ultraviolet absorbance of the oligomers, detection limits in the low ppb range were obtained without derivatization.

Advances in amyloidosis

Major advances of the past year in the amyloidoses include a better understanding of the polymorphism of the acute-phase reactant serum amyloid A protein and the appearance of a new mouse model for primary amyloidosis. The list of single point mutations in transthyretin in different families with slightly varied clinical manifestations of the disease continues to grow. Gelsolin, with its asparagine 187 mutation, was found to cause amyloidosis beyond the borders of Finland, where it has been extensively evaluated. The incredible range of osteoarticular lesions due to beta 2-microglobulin in hemodialysis amyloidosis continues to expand and includes severe manifestations of spondyloarthropathy. The greatest number of papers in the amyloid literature have involved amyloid beta protein, amyloid beta protein precursor associated with Alzheimer's disease, and prion protein associated with the spongiform encephalopathies. The widespread systemic involvement of amyloidosis has led to the appearance of a host of manifestations, some common and some rare. Treatment advances focus on the use of liver transplantation in familial amyloid polyneuropathy to remove the source of mutant protein synthesis.

Intraperitoneal amyloid formation by amyloid enhancing factor — rich macrophages in ascitic fluid

Although resident peritoneal cells from amyloidotic mice (amyloidotic peritoneal cells) are capable of processing the precursor protein of secondary amyloidosis, serum amyloid A (SAA) to amyloid fibrils, the peritoneum is a rare site for amyloid deposition. This is considered to be due to a deficiency of SAA in the peritoneum. To increase the supply of SAA to the peritoneum, ascitic fluid containing about the same protein constituents as in the serum was induced in mice. Amyloidotic peritoneal cells were packed in a microchamber which was shielded with filter membranes, and cultured in ascitic fluid supplemented with additional inflammatory factors. On the 7th day, Congo red-positive structures which showed green birefringence under polarized light were found inside and occasionally outside the chamber. By anti-AA or -SAA immunostaining, amyloid deposits and the cell surfaces of macrophages were positive. Immunologic depletion of T- and B-lymphocytes from the amyloidotic peritoneal cells did not adversely effect the amyloid formation in microchambers. These results suggest that either ascitic fluid containing sufficient amounts of SAA, or peritoneal macrophages with a high amyloid enhancing factor (AEF) activity are indispensable for AA amyloid fibrillogenesis in the peritoneum.

High-performance capillary electrophoresis of SDS-protein complexes using UV-transparent polymer networks

This paper demonstrates the use of UV-transparent replaceable polymer networks for the separation of SDS-protein complexes on the basis of molecular weight. First, the use of linear (i.e. non-cross-linked) polyacrylamide is shown to provide molecular separation of SDS-protein complexes. A study reveals such columns to yield significantly greater lifetime than cross-linked gels because of the flexibility of the noncovalently attached polymer chains. However, column lifetime was still found to be limited (approximately 20-40 injections), and detection at 214 nm was problematical because of the absorbance of polyacrylamide. UV-transparent polymer networks of dextran and PEG were substituted for polyacrylamide with successful molecular weight sieving of SDS-protein complexes at 214 nm. Due to their low to moderate viscosities, these networks could be routinely replaced leading to the possibility of hundreds of injections with a single column. Migration time reproducibilities of 0.5% RSD or less were found with replacement of the network. Using dextran, calibration plots of peak area vs concentration of standard protein were linear over the range of 0.5 microgram/mL up to at least 0.25 mg/mL. Furthermore, plasma samples could be directly utilized because of the strong solvating power of SDS. Rapid separation of protein mixtures are demonstrated with these UV-transparent polymer networks.

Demonstration of plasma proteinase inhibitors in beta 2-microglobulin amyloid deposits

beta 2-microglobulin-related amyloidosis (A beta 2M) represents a frequent complication in long-term dialysis patients. Although the pathogenetic mechanism has yet to be fully understood, it is known that amyloid fibrils usually consist of intact molecules of beta 2-microglobulin (beta 2m). Plasma proteinase inhibitors (PPI) are a broad family of glycoproteins with the function of eliminating unwanted proteolysis of serine proteases. Their role in amyloidogenesis has become a subject of intense discussion, especially since the recent identification of alpha 1-antichymotrypsin in the beta-protein amyloid deposits of Alzheimer's disease. We evaluated immunohistochemically and biochemically the presence and distribution of several PPIs (alpha 1-proteinase inhibitor, alpha 1-antichymotrypsin, antithrombin III, alpha 2-macroglobulin and tissue inhibitor metalloproteinase) and amyloid P component in A beta 2M deposits in osteo-articular and visceral tissues from dialysis patients with amyloidosis, as well as two carpal tunnel synovia from non-dialysis patients and one Alzheimer's brain as controls. The immunohistochemical study demonstrated that all but one (anti-alpha 1-antichymotrypsin) of the PPI antibodies tested showed varying degrees of positive reaction against A beta 2M deposits. All the antibodies (including anti-alpha 1-antichymotrypsin) also reacted to some extent with other non-amyloid visceral and connective tissue elements diffusely and/or selectively. Among them, only the reaction of anti-amyloid P component had significantly distinctive localization to A beta 2M deposits, which were identified in adjacent serial sections by Congo red staining and immunohistochemical reaction against anti-beta 2m.(ABSTRACT TRUNCATED AT 250 WORDS)

A New Transthyretin Mutation Associated with Amyloidotic Vitreous Opacities

An inherited type of amyloidosis was suspected in an individual of Italian descent who presented with vitreous opacities. Although no family history of amyloidosis was apparent, the patient's transthyretin gene was examined and found not to possess any of the known transthyretin mutations. Complete DNA sequencing revealed a substitution of adenine for thymine in the second base of codon 84 causing an amino acid change of asparagine for isoleucine. The mutation was confirmed by demonstrating the loss of an Sfa N1 restriction endonuclease site. Allele-specific DNA amplification by polymerase chain reaction also was used to confirm the mutation. Either of these tests can be used for diagnosis. Asparagine 84 represents the second mutation associated with amyloidosis to occur at codon 84.

Amyloid and amyloidosis

Discovery of the different proteins that constitute the multiple types of amyloid has led to an increasing variety of studies in the literature of diverse medical subspecialties. In fact, in this review, the editors have chosen to review the beta 2-microglobulin amyloid of long-term hemodialysis in the section on renal disease. The current review focuses on the rapidly advancing basic studies of familial, amyloid A protein amyloid and the relevant clinical studies, although the research on amyloid light-chain protein and other forms of amyloidosis is also noted.

Familial amyloidotic polyneuropathy: a new transthyretin position 30 mutation (alanine for valine) in a family of German descent

Familial amyloidotic polyneuropathy (FAP) is a dominantly inherited form of amyloidosis usually associated with an abnormal transthyretin (TTR), previously known as prealbumin. Several disease-related variants of the protein, each with a different amino acid substitution and correlating DNA point mutation, have been identified. The TTR gene from a patient suffering from this disorder was asymmetrically amplified and directly sequenced, revealing a cytosine for thymine substitution in the second base of codon 30 and the creation of a novel Cfo I restriction endonuclease site in exon 2. This mutation results in a previously undescribed substitution of an alanine for valine in the final TTR protein. Analysis of the amino acid mutation reveals it to be a hydrophilic substitution at a hydrophobic core position. Alanine at position 30 represents the second FAP-associated mutation at position 30 in TTR.