Human alpha-fetoprotein and its purification by chromatography on immobilized estrogens.

Human alpha-fetoprotein (AFP) was isolated from human abortive tissue by biospecific chromatography on immobilized estrogens. The most effective sorbents were: estrone-0-3-hemisuccinyl-hexamethylenediamine-Sepharose CL 4B and diethylstilbestrol-diasoanisole-sulfonyl-oxyethyl-Sepharose CL 4B. As elution solution the most optimum was 10% buffered aqueous butanol. Taking into consideration the data obtained, one can conclude that AFP in human biological fluids is bound to immobilized estrogens. Butanol extraction deestrogenizes AFP, and as a result human AFP acquires affinity to immobilized estrogens. During rechromatography on immobilized diethylstilbestrol, it was possible to obtain AFP preparations of about 95% purity. The present results provide the opportunity to work out new methodological approaches to human AFP isolation using biospecific chromatography on immobilized estrogens.     

Carcinoma of thyroid--clinical presentation and outcome.

The clinical, biochemical and pathological features of 31 patients with thyroid carcinoma managed at Hospital Universiti Sains Málaysia, Kubang Kerian from 1985 to 1989 were analyzed. There were 25 females and 6 males. The types of carcinoma were: papillary-17 cases; follicular-10 cases; medullary-2 cases and anaplastic-2 cases. For papillary carcinoma the mean age of the patients was 52.9 years. For follicular carcinoma the mean age was 48.3 years, for medullary carcinoma, 48.5 years and for anaplastic, 74.5 years. All patients had pre-existing goitre except for 2 and most presented with advanced disease. The mean duration of symptoms for papillary carcinoma was 3.7 years, follicular carcinoma 1.6 years, medullary carcinoma 13.5 years and anaplastic carcinoma 6 months. 12 patients presented with goitre of increasing size; 9 had compression symptoms; 4 presented with cervical lymph node enlargement and 6 presented with bony pains of whom 2 had paraplegia. None of the patients were ever thyrotoxic or hypothyroid. Treatment in general was unsatisfactory because of patients' non-acceptance of surgery and/or radioactive iodine.     

Assembly, disassembly, and exchange of glial fibrillary acidic protein

The kinetics and dynamics of glial fibrillary acidic protein (GFAP) assembly was explored by a fluorescence energy transfer assay method. Purified GFAP was stoichiometrically labeled at a single cysteine residue with fluorescein-maleimide. Soluble labeled GFAP in a low ionic strength buffer was assembled into 10 nm filaments by rapidly increasing the ionic strength, and the kinetics of GFAP assembly was monitored by the reduction in fluorescence due to self-quenching of fluorescein. The extent of fluorescence quench correlated with both the formation of 10 nm filament morphology and the amount of protein pelleted at 12,000g. The assembly of GFAP is critically dependent upon both protein and magnesium ion concentration, and at the critical concentration for GFAP assembly is approximately 40 micrograms/ml. Disassembly of GFAP filaments was also observed as a relief of fluorescence quenching after dilution of labeled GFAP filaments. When labeled GFAP filaments were mixed with an excess of unlabeled filaments, a rapid increase of fluorescence was observed, which is due to an exchange of subunits between labeled and unlabeled GFAP filaments. These results indicate that GFAP filaments are dynamic structures and that a small pool of kinetically active unassembled GFAP subunits are in a dynamic equilibrium with assembled GFAP filaments. The ability of GFAP to assemble, disassemble, and undergo subunit exchange has important implications for the organization and dynamics of astroglia cell cytoskeleton during development and in response to injury.     

A trial of prophylactic thiotepa or mitomycin C intravesical therapy in patients with recurrent or multiple superficial bladder cancers

There were 40 consecutive patients with recurrent or multiple superficial stage Ta or T1 transitional cell cancer assigned randomly to receive prophylactic thiotepa or mitomycin C intravesical chemotherapy. Patients received 8 weekly instillations followed by 22 monthly treatments of either 60 mg. thiotepa or 40 mg. mitomycin C. Of 25 patients randomized to receive mitomycin C 4 had recurrence in a total of 337 patient-months (1.19 per 100 patient-months), while disease recurred in 1 of 15 patients randomized to receive thiotepa who were followed for a total of 220 patient-months (0.45 per 100 patient-months). No significant difference in recurrence rate was noted for either drug group (p equals 0.18). Toxicity requiring cessation of therapy was observed in 7 patients (28 per cent) on mitomycin C and none on thiotepa.     

Absence of highly homologous sequence to HTLV-I in Japanese multiple sclerosis

We tried to detect HTLV-I-related sequences in Japanese patients with multiple sclerosis with a highly sensitive method that employs the polymerase chain reaction (PCR) of genomic DNA followed by Southern blot hybridization analysis. To amplify HTLV-I sequences, we used primers for LTR, pol, gag, and env coding regions. Fourteen patients with definite MS, 14 disease controls, 12 normal controls, and 3 patients with HTLV-I-associated myelopathy (HAM) were investigated. Results of particle aggregation assay for HTLV-I antibodies were negative in serum from all subjects except for the 3 HAM patients. Neither the 14 MS patients nor the 26 controls showed the presence of any highly homologous sequences to HTLV-I. We did observe faint signals for gag, pol, and env coding regions only at low stringent hybridization in some MS patients as well as some normal controls. The nucleotide sequence analysis of the faint bands was more homologous to major histocompatibility complex molecules than the HTLV-I genome.     

Dental materials in pediatric dentistry.

Dental materials for the restorative armamentarium in pediatric dental care continue to improve in esthetics and function. This review describes the application of some contemporary materials and concepts. Fluoride-releasing glass ionomers are appropriate for use as luting cements and as liners and bases. The glass ionomer cements have minimal solubility in oral fluids and possess the capability of inhibiting secondary caries. Amalgam and composite resin are effective for class II restorations, although amalgam placement is considerably less time consuming and less technique sensitive. Composite resins, particularly more highly filled resins, are appropriate for anterior restorative care. The use of ceramic glass inserts may provide strength and decrease restorative time for composite resin restorations in the future. When planning treatment for pediatric dental patients, each patient and restorative material to be used should be evaluated on an individual basis, in order to provide appropriate care within each material's limitations. Pediatric restorative dentistry involves the use of many materials. As materials improve in durability, strength, esthetics, and anticariogenic properties, the concepts of contemporary pediatric restorative dentistry change. Certainly, the traditional principles of restorative dentistry remain practical and significant in the practice of dentistry. Although these traditional concepts are extremely relevant, newer materials allow for modifications to be made during treatment planning in restorative dentistry. This review presents some newer materials and concepts and their applications in current pediatric restorative dentistry.     

Role of basal insulin in the regulation of protein kinetics and energy metabolism in septic patients.

We have investigated the role of basal insulin concentration on leucine kinetics (determined by means of 1-[13C]leucine) and energy metabolism (determined by indirect calorimetry) in eight septic patients by reducing insulin (and glucagon) secretion by somatostatin infusion. Basal glucagon concentration was elevated (744 +/- 381 pg/mL), and insulin concentration was normal (10 +/- 4 microU/mL). Basal resting energy expenditure (REE) was 151 +/- 8% that of predicted basal energy expenditure, and leucine appearance (Ra), oxidation, and nonoxidative disposal rates were all elevated above the normal ranges. Somatostatin infusion reduced insulin concentration by 52% and glucagon concentration by 64%. This resulted in a significant increase in the rate of leucine oxidation from 0.96 +/- 0.08 to 1.18 +/- 0.14 mumol/kg/min (p less than 0.01), and nonoxidative leucine disposal decreased from 2.95 +/- 0.18 to 2.67 +/- 0.17 mumol/kg/min (p less than 0.01). Somatostatin infusion also caused significant increases in REE and fat oxidation from 1310 +/- 100 to 1505 +/- 128 kcal/m2/day (p less than 0.05) and from 1.72 +/- 0.24 to 2.41 +/- 0.41 mg/kg/min, respectively, and a slight decrease of carbohydrate oxidation from 1.51 +/- 0.49 to 1.31 +/- 0.49 mg/kg/min. These metabolic responses can be attributed to the reduction in insulin concentration, because they are in the opposite direction of changes that would occur as a consequence of a reduction in glucagon concentration. We conclude that the basal insulin plays an important role in attenuating net protein loss and energy expenditure.     

Studies of the human oropharyngeal airspaces using magnetic resonance imaging IV--the oropharyngeal retention effect for four inhalation delivery systems.

Magnetic resonance imaging (MRI) of the oropharyngeal region from 20 adult volunteers using four model inhalation devices (varying mouthpiece diameters, airflow resistances) and tidal breathing was carried out. Statistical analysis (convex hull method) selected 12 scans from 80 data sets representing the extremes of all dimensions in the population. Twelve physical mouth-throat models were made by stereolithography using the exact scan data. The aim was to produce models with varying dimensions to span the adult population, and to investigate if oropharyngeal dimensions affected throat retention for different delivery systems. In an in vitro analysis, the models were used to determine the retention effect of the oropharyngeal airspaces when drug aerosols were administered from four inhalation delivery systems: a pressurised metered dose inhaler (pMDI), two different dry powder inhalers (DPIs A and B), and a nebulizer. The aims of this work were to determine the key parameters governing mouth-throat retention and whether retention was dependent on the delivery system used. Characterizing the throat models by measuring 51 different dimensional variables enabled determination of the most influential variables for dose retention for each inhalation delivery system. Throat model retention was found to be dependent on the delivery system (pMDI approximately DPI(A) > DPI(B) > Neb.). The most influential variable was the total throat model volume. Throat models representing high, median, and low oropharyngeal filtration in healthy adults have been identified.