Object-based three-dimensional X-ray imaging

A form of three-dimensional X-ray imaging, called Object 3-D, is introduced, where the relevant subject material is represented as discrete ‘objects’. The surface of each such object is derived accurately from the projections of its outline, and of its other discontinuities, in about ten conventional X-ray views, distributed in solid angle. This technique is suitable for many applications, and permits dramatic savings in radiation exposure and in data acquisition and manipulation. It is well matched to user-friendly interactive displays.     

Soluble and membrane-bound forms of brain acetylcholinesterase in Alzheimer''s disease

In order to determine the effect of Alzheimer's disease on the relative distribution of soluble and membrane-bound molecular forms of acetylcholinesterase (AChE) in the brain, postmortem samples (delay interval less than 12 h) were obtained from parietal cortex (Brodmann area 40) and hippocampus as well as the areas containing their respective projection nuclei, i.e., substantia innominata and septal nucleus, in 9 patients with Alzheimer's disease (AD) and 4 normal controls. The monomer (G₁), dimer (G₂), and tetramer (G₄) forms of AChE were examined. In AD compared to controls, significant changes occurred in area 40 and hippocampus but not in the areas containing projection nuclei, and included loss of mean total AChE activity, decrease in the relative percentage of membrane-bound G₄, and increase in the relative percentage of soluble G₁---G₂. Percent of soluble G₄ was unaffected in AD brain. In area 40 but not hippocampus a large increase in percent membrane-bound G₁-G₂ occurred. Thus, these results emphasize that the selective decrease in membrane-bound G₄ accounts for the decrease in total G₄ activity in AD brain.     

Microvasculature of the buffalo epididymis

The microvasculature of the water buffalo (Bubalus bubalis) epididymis was investigated using light (LM), scanning electron (SEM), and transmission electron (TEM) microscopy techniques. SEM analysis of the buffalo epididymis showed fenestrations that occupied ovoid inside the endothelium of the postcapillary venules located in the caput, corpus, and cauda. They varied in shape and dimension, but more importantly, they connected the venules of the blood vascular system to the capillaries of the peripheral lymphatic vascular system. Morphofunctional analysis of these connections suggests that the microvasculature of the buffalo epididymis plays a role in facilitating the circulation of biologically active substances, and the absorption and secretion processes necessary for the survival and maturation of spermatozoa. The lymphatic capillaries at the connection points formed a network of variously sized polygonal links. These capillaries then converged to form the precollector lymphatic vessels, which in turn converged with the larger vessels originating from the testis. It was further noted that in the capillary endothelium there were no fenestrations, and in the large veins there were many diverticula. These diverticula appear to play a role in the regulation of the seasonal variations of the blood reflux. In general, the microvascular architecture of the buffalo epididymis, particularly its connection to the lymphatic vascular system, appears to play an important role in the absorption and secretion processes of the epididymal epithelium. Anat Rec 266:58–68, 2002. © 2002 Wiley‐Liss, Inc.     

De novo 13q partial duplication identified by cytogenetic, biochemical and molecular approaches

A 3.5-month-old female infant manifesting dysmorphic facies, developmental delay and failure to thrive was referred for cytogenetic evaluation. Peripheral lymphocytes revealed three chromosomally distinct cell lines: 46,XX/46,XX,10p+/47,XX,10p+,+mar. Dermal fibroblasts revealed only the 46,XX,10p+cell line. High resolution G-, R-, and Q-banding suggested that the extra chromosomal material (10p+) represented a duplication of the segment 13q14----13qter. Parental karyotypes were normal. As absolute identification of de novo chromosomal abnormalities, based solely on cytogenetic studies, is sometimes difficult, both biochemical and molecular approaches were undertaken to elucidate this abnormality in more detail. Dosage effects were examined using esterase D (localized to 13q14.1) and the DNA probes p1E8 and p9A7 (localized to 13q22 and 13q31/32, respectively). These studies suggested the presence of only 2 copies of esterase D, but 3 copies of both DNA probes, allowing identification of the breakpoint at 13q14.2.     

An immunoblotting procedure for screening glycophorins and band 3 protein in the same blots: Identification of glycophorin and band 3 variant forms

An immunoblotting procedure is described which makes it possible to screen multiple blood samples for the presence of glycophorin and band 3 variant forms with altered electrophoretic mobility. The procedure can be simplified by using whole red blood cell hemolysates instead of membranes for SDS-polyacrylamide gel electrophoresis. The use of hemolysates also has the advantage that antigens sensitive to proteolysis are not degraded in vitro. The same nitrocellulose blots were used for immunoenzymatic detection of glycophorins with a set of anti-glycophorin monoclonal antibodies, and for autoradiographic detection of band 3-derived bands with ¹²⁵I-labeled anti-band 3 monoclonal antibody. The screening of 157 Caucasian blood samples revealed the presence of a slower-migrating form of band 3 in seven cases and variant glycophorin in one case. The variant glycophorin exhibited the features of hybrid glycophorin of B-A type.     

Regulation of the trehalose-6-phosphate synthase complex in Saccharomyces

Summary Trehalose-6-phosphate synthase is another example of an enzyme of carbohydrate metabolism, in Saccharomyces, which could be regulated by interconversion of forms. Deactivation was mediated both in vivo and in vitro by a cyclic AMP-dependent protein kinase. Reversibility of this process was obtained by a phosphatase treatment leading to an increase in activity. The phosphorylated, less active form of the enzyme proved to be more susceptible to activation by ATP.Mg. Mutants with well defined lesions in the cyclic AMP-dependent protein kinase system were used to corroborate our findings of a possible regulatory mechanism of trehalose-6-phosphate synthase activity by interconversion of forms.Abbreviations PMSF phenyl-methyl-sulfonyl fluoride - G-6-P glucose-6-phosphate - UDPG uridine-5-diphosphoglucose - PEP phosphoenol pyruvate - NAD⁺ -nicotinamine adenine dinueleotide - ATP adenonise 5-triphosphate - cAMP adenosine 2:3-cyclic monophosphate - MOPS 3 (N-morpholino) propanesulfonic acid     

Einsparung von Diclofenac durch B-Vitamine: Ergebnisse einer randomisierten Doppelblindprüfung mit reduzierten Tagesdosierungen von Diclofenac (75 mg Diclofenac versus 75 mg Diclofenac plus B-Vitamine) bei akuten Lendenwirbelsäulensyndromen

Summary Pain syndromes of the lumbar spine are one of the main problems in orthopedic practice. The therapeutic effect of NSAIDs is not subject to doubt in this connection.But considering that the application of NSAIDs is frequently associated with side effects, a reduction of dosage would be to the patient's benefit. Clinical studies have shown that concomitant treatment with vitamins B₁, B₆, B₁₂ and diclofenac leads to a more efficient pain relief than treatment using diclofenac alone and thus provides the possibility of saving NSAIDs.This clinical trial was carried out in order to determine whether these results can also be achieved when a reduced dosage of diclofenac (75 mg daily) is used.123 patients with acute pain syndromes of the lumbar spine were treated with either B-vitamins and diclofenac or diclofenac alone for a maximum of 7 days. There was the option to terminate therapy in the trial after 3–4 days in the case of total pain relief.45 patients could stop the treatment due to remission of symptoms. 30 patients belonged to the combination therapy group, the other 15 took diclofenac alone; this difference is statistically significant (p< 0.05).All parameters concerning pain relief and movement of the vertebral column showed statistically significant differences in favour of the B-vitamin-diclofenac-combination, too.The results document the positive influence of B-vitamins on painful vertebral syndromes and indicate that B-vitamins contribute to saving of NSAIDs by shortening the treatment time and reducing daily NSAID-dosage.

     

A polyexponential deconvolution method. Evaluation of the “gastrointestinal bioavailability” and meanin vivo dissolution time of some ibuprofen dosage forms

A new deconvolution algorithm (DCON) suitable for pharmacokinetic applications is presented. It requires that both the impulse and input responses, typically systemic drug levels, be well described by polyexponential equations. DCON has a wider range of applications than an earlier method (DECONV) from which it is derived. A FORTRAN program is provided, making implementation of the technique a simple matter. DCON is demonstrated to evaluate the GI bioavailability, defined as the rate and the extent of gastrointestinal drug release, of various ibuprofen dosage forms. The GI drug release kinetics exemplifies a pharmacokinetic system which cannot be evaluated using the previous deconvolution algorithm (DECONV) because of an initial zero drug level response. This limitation is not found in DCON. It is also demonstrated how the mean in vivo dissolution time MDT can be evaluated by deconvolution.     

Serum digoxin concentrations in a representative digoxin — Consuming adult population

Summary As part of health examination of a representative sample of an adult population (n=8000) serum digoxin concentration was measured in 661 patients on continuous digoxin therapy. The prescribed mean daily dose of digoxin was significantly higher in men (223 µg) than in women (201 µg); the dose significantly decreased with increasing age. The mean serum digoxin concentration was the same in men and women and it differed insignificantly between age groups, although older persons tended to have a higher concentration. The age — adjusted mean steady state digoxin concentration was 1.02 ng/ml in men and 0.98 ng/ml in women; in about 60% the concentration was within the therapeutic range (0.80–2.00 ng/ml). The concentrations were clearly related to daily dose of digoxin. At equal dose levels old persons tended to have higher concentrations than younger persons. The interindividual variation in serum digoxin concentrations was very wide. However, when digoxin measurements in the same subjects were repeated about three months later, a good correlation between the two measurements was found. The interval between the last dose of digoxin and the collection of blood (up to 41 h) had relatively little effect on individual serum digoxin concentrations. Patients on concomitant thiazide or loop diuretic therapy had the same mean serum digoxin concentration as those not-receiving a diuretic. The mean concentration was significantly higher in patients taking a thiazide or loop diuretic combined with triamterene. The difference may have been due to an interaction between triamterene and digoxin.