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PubMed1996

Effect of different experimental parameters on the potentiometric evaluation of blood electrolytes using K+ as a test cation.

Potentiometric evaluation of ionic concentrations in physiological media has been reported to be significantly affected by the albumin containing matrix. Previous studies have attempted to clarify the origin of different patterns of variation of E versus albumin concentration at a constant 0.01 mol dm-3 KCl, depending on the experimental methodologies. This paper reports on measurements of K+ in albumin (BSA) containing KCl solutions, which have been pursued following different methodologies concerning the sequence of measurements, i.e., starting either from the most concentrated solution (100 g dm-3) (A) or from the most dilute solution (20 g dm-3) (B), and solution preparation, (a) dilution of an initial 100 g dm-3 albumin solution by successive addition of 0.01 mol dm-3 KCl, (b) concentration of an initial 20 g dm-3 albumin solution by addition of solid substance, (c) independent preparation of each albumin solution (20, 40, 60, 80 and 100 g dm-3) or (d) preparation of each albumin solution from direct dilution of a 100 g dm-3 stock solution with 0.01 mol dm-3 KCl. Convenient calculations were made and showed a significant contribution of albumin to the liquid-liquid junction potential. The variation of potential with albumin concentration is smaller for hypertonic than for isotonic bridge solutions, both for the dilution series (A,a and A,d) and for the concentration series (B,c and B,d). When the method for increasing the concentration is performed by addition of a solid substance to an initially diluted albumin (B,b), the slope of the E versus albumin concentration plot is larger for hypertonic than for isotonic reference electrolytes. This latter finding is in agreement with Payne's results when ultrafiltration was used to concentrate a protein solution. These observations are a clear indication that the method of preparation of concentrated protein solutions may significantly affect the results.

Electrodes↗
PubMed1976

Electrophoretic analysis of multiple forms of myosin in fast-twitch and slow-twitch muscles of the chick.

1. A method is described for the electrophoretic analysis of intact myosin in polyacrylamide gel in a buffer system containing 0.02 M-pyrophosphate and 10% (v/v) glycerol, pH 8.8. 2. In this system chicken skeletal-muscle myosins reveal five distinct electrophoretic components, three components from the fast-twitch posterior latissimus dorsi muscle and two slower-migrating components from the slow-twitch anterior latissimus dorsi muscle. 3. The Ca2+-activated ATPase (adenosine triphosphatase) activity of myosin components was measured by densitometric scanning of the gel for the Ca3(PO4)2 precipitate formed during the ATPase reaction and subsequently for stained protein. Each component from the same muscle appears to have identical ATPase activity, but components from the fast-twitch muscle had an activity 2.2 times higher than those from the slow-twitch muscle. 4. On re-electrophoresis in the same buffer system, individual fractions of fast-twitch myosin did not reproduce the three-band pattern of the original myosin, but migrated at rates consistent with their original mobility. 5. Analysis of the mobility of the three fast-twitch myosin components in gels of different concentrations suggests that they are not stable oligomers of each other. 6. It is suggested that these components of fast-twitch myosin and slow-twitch myosin are isoenzymes of myosin.

Adenosine Triphosphatases↗
PubMed2000

The arterial supply to the digits of the forelimb in the Bactrian camel (Camelus bactrianus).

The arterial supply of the digits of the forelimb of the Bactrian camel is described. The arteries supplying the digits were the palmar metacarpal and common palmar digital arteries III. The palmar metacarpal artery III was the continuation of the deep medial proximal metacarpal branch which was derived from the medial branch of the radial artery. It gave rise to a nutrient branch, medial branch, lateral branch and distal perforating palmar branch at the proximal end of the distal sixth of the cannon bone (fused third and fourth metacarpal bones). The common palmar digital artery III was the continuation of the median artery, which divided into medial and lateral branches. The medial branch of common palmar digital artery III which occasionally arose from the axial palmar proper digital artery III, after giving rise to the axial proximal proximal phalangeal branch, divided into the axial and abaxial palmar proper digital arteries III. The axial palmar proper digital artery III gave off the dorsoaxial distal proximal phalangeal, dorsoaxial proximal middle phalangeal, dorsoaxial distal middle phalangeal, palmoaxial middle phalangeal, palmoaxial distal phalangeal, dorsoaxial distal phalangeal branches, coronal artery and some digital tori branches. The abaxial palmar proper digital artery III gave rise to the abaxial proximal proximal phalangeal, dorsoabaxial distal proximal phalangeal, dorsoabaxial middle phalangeal, palmoabaxial middle phalangeal, palmoabaxial distal phalangeal, dorsoabaxial distal phalangeal branches, coronal artery and some digital tori branches. The lateral branch of the common palmar digital artery III in its origin, course, branching pattern and supply in the fourth digit was similar to the medial branch of common palmar digital artery III in the third digit.

Adaptation, Physiological↗
PubMed2003

Use of finasteride in the treatment of men with androgenetic alopecia (male pattern hair loss).

Finasteride, a type 2-selective 5alpha-reductase inhibitor, was approved in 1997 as the first oral pharmacologic therapy for the treatment of men with androgenetic alopecia (AGA; male pattern hair loss). Originally developed for the treatment of men with benign prostatic hyperplasia (BPH) at a dose of 5 mg/day, finasteride has a well-established, excellent safety profile. Subsequent studies demonstrated that finasteride was an effective treatment for men with AGA at an optimal dose of 1 mg/day. This report summarizes the published peer-reviewed literature on the use of finasteride in the treatment of men with AGA, including the data on long-term (5 years) use of finasteride in a placebo-controlled clinical trial environment.

Alopecia↗
PubMedDate not supplied

Evolution of male sexual characters in the oriental Drosophila melanogaster species group.

Understanding the genetic and molecular mechanisms of morphological evolution is one of the greatest challenges in evolutionary biology. Sexually dimorphic traits, which often evolve at a high rate due to their involvement in mate choice and sexual selection, present unique opportunities for investigating changes in development over short evolutionary distances. Phylogenetic analysis is essential to provide a historical framework for comparative studies of development by establishing the order and polarity of morphological changes. In this report, we apply a new molecular phylogeny to reconstruct the evolution of male sexual characters in a group of species closely related to the model species Drosophila melanogaster. These highly variable traits include wing melanin patterns, the sex comb, and the structure of external genitalia and analia. We show that sexually dimorphic characters can diverge very rapidly among closely related species. More surprisingly, we also find a pervasive pattern of independent origin and secondary loss of male sexual traits in different evolutionary lineages.

Animals↗
PubMed2002

Anti-HCV confirmatory testing of voluntary blood donors: comparison of the sensitivity of two immunoblot assays.

BACKGROUND: In this study, the sensitivity of two commercially available anti-HCV immunoblot assays (HCV Western blot (Wellcozyme] and RIBA 3.0 SIA [RIBA-3, Chiron]) was compared in a voluntary blood donor population. STUDY DESIGN AND METHODS: Four groups of donor samples were retrospectively tested in this study. Groups 1 and 2 were donor samples that gave positive or indeterminate band patterns, respectively, when originally tested on the HCV Western blot between 1994 and 1998. These samples were tested on the RIBA 3.0. Donor samples in Groups 3 and 4 were originally tested on RIBA-3 during 1998 and 1999 and gave positive or indeterminate blot results, respectively. In this study these two groups were tested on the HCV Western blot. Samples with discrepant results on the two immunoblot assays were selected for genotyping or serotyping. RESULTS: The two immunoblots showed similar sensitivity to the core and NS5 proteins. However, of 35 samples positive on Western blot or RIBA-3, the Western blot failed to detect NS4 in 14 samples compared with only 5 for RIBA-3. As well, the Western blot failed to detect NS3 in 6 samples compared to 2 for RIBA-3. Five (27.8%) of 18 samples that were Western blot indeterminate due to core reactivity showed an additional NS3 band on RIBA-3. Of the samples with additional NS3 and/or NS4 reactivity on RIBA-3 that were genotyped or serotyped, all were HCV type 3. CONCLUSIONS: Western blot and RIBA-3 showed similar sensitivity to the HCV core and NS5 proteins. However, RIBA-3 showed greater sensitivity to both NS3 and NS4 compared to the Western blot. The reduced sensitivity of the Western blot to the NS3 and NS4 proteins was observed with HCV type 3 samples.

Blood Donors↗
PubMed1981

[Neurotoxic side effects of cytostatic therapy (author's transl)].

As the advances in the field of cytostatic substances gain ground, more and more side effects and complications become manifest in the nervous system. Although the neurotoxic effects produced by different cytostatics present a different appearance and are partly of only sporadic or slight clinical importance, there is hardly a cytostatic which does not exercise a side effect on the nervous system. Definition of the side effects in the nervous system which are caused by cytostatics, is often difficult, because the neurotoxic syndromes are similar to disease patterns of different origin, especially those of the neoplastic and paraneoplastic type, both topically and clinico-phenomenologically. However, it is often of vital importance to arrive at the correct diagnosis well in time, because this will help the physician to decide whether the cytostatic should be discontinued or administered as before. For this reason, it may be necessary to employ, besides the neuropsychiatric examination, additional electrophysiological, CSF-diagnostic, CT and bioptic methods.

Antineoplastic Agents↗
PubMed1991

A case of an intramural coronary artery associated with transposition of the great arteries.

One case of an intramural coronary artery in association with transposition of the great arteries is presented. A 16-month-old infant was admitted for the second-stage operation of complete transposition after a subclavian patch plasty for the aortic isthmus stenosis, division of the persisting arterial duct, and pulmonary artery banding had been performed in the first-stage operation soon after birth. The primarily planned arterial switch operation was, however, not performed because of an unusual coronary artery morphology and pattern--a separated origin of both coronary arteries from the posterior, "facing" sinus of Valsalva and an intramural course of the left anterior descending artery. This very rare case of coronary artery variation is presented from the surgical point of view.

Abnormalities, Multiple↗
PubMed1996

[Epidurography: comparison with CT, spiral CT and MR epidurography].

PURPOSE: The purpose of this study was to explain the origin of image patterns demonstrated by conventional epidurography, which is a controversially discussed topic in recent literature. MATERIAL AND METHODS: After introduction of thoracic epidural catheters and iopamidol injection, conventional epidurography and CT-epidurography were performed on 25 preoperative patients. After injection of Gadolinium-DTPA MR-epidurography was performed in two patients treated for chronic pain with already introduced epidural catheters. Three volunteers also underwent identical imaging after introduction of thoracic epidural catheters and in addition helical-CT epidurography using twin-beam technology. RESULTS: 40% of the patients demonstrated the railroad track phenomenon. We were able to prove that it is a sign of a rhythmically variable filling of segments of the lateral epidural space with contrast medium 76% of the patients demonstrated no ventral epidural space at the thoracic level. 56% of the patients showed a medial area of translucence combined with a band-shaped contrasting of the epidural space in the standard ap view. This was proven in all cases to be a plica mediana dorsalis by CT. In all volunteers who underwent helical-CT and MR epidurography we observed the railroad track phenomenon and the filling defect of the anterior thoracic epidural space. CONCLUSION: CT epidurography is well suited for obtaining new insights into the interpretation of findings obtained by conventional epidurography.

Analgesia, Epidural↗
PubMed1984

A correlative synopsis of the leukodystrophies.

Leukodystrophies are disorders affecting primarily oligodendroglial cells or myelin. Another necessary criteria for defining a leukodystrophy is that the disorder has to be of endogenous origin with a pattern compatible with genetic transfer of a metabolic defect. The clinical criterion of a steadily progressive deterioration of function must also be included. Much of the material presented during the conference related to three leukodystrophies from which subclasses with a relatively uniform clinical presentation can be distinguished and about which a considerable body of consistent biochemical information is available. These disorders are metachromatic leukodystrophy (MLD), globoid leukodystrophy (GLD, also referred to as Krabbe's disease) and adrenoleukodystrophy (ALD). Discussion was focused to the pathophysiology of the more prevalent "classical" subclass of each of these disorders; discussion of clinical variants was in the context of what we could learn about the more prevalent form. Finally, because of time restraints, most of the discussion on the final day was centered around MLD. This clinical disorder was used as a starting point for discussion of questions both specific to MLD as well as those questions common to all leukodystrophies. The discussion of GLD and ALD was more restricted and only points relevant to those specific leukodystrophies were discussed. Information from the presentation not dealing directly with these human disorders is also summarized.

Adrenoleukodystrophy↗
PubMed1974

Interaction between mendelian and non-mendelian genes. Regulation of the transmission of non-mendelian genes by a mendelian gene in Chlamydomonas reinhardtii.

The non-Mendelian genetic element of a given mating type of Chlamydomonas reinhardtii was first doubly marked by succesive mutageneses and then transferred into a number of offspring cells of the opposite mating type. In subsequent crosses of these offspring clones, the transmission pattern of the original non-Mendelian markers was analyzed. The results indicate that the mating-type gene of a given cell regulates the transmission and perhaps the recombination of the non-Mendelian genes regardless of whether the non-Mendelian markers were isolated originally in the same cell or obtained from another cell of the opposite mating type through genetic transmission. The regulation of the transmission of non-Mendelian genes in C. reinhardtii is thus apparently different from the autonomous control of the transmission of non-Mendelian mitochondrial genes in yeast by a genetic factor located on the mitochondrial genome.

Chlamydomonas↗
PubMed1980

Integrated and free viral DNA in hamster tumors induced by BK virus.

BK virus (BKV)-induced tumors in hamsters were investigated for the presence of viral DNA by the blot-transfer hybridization technique. Several viral genomes per cell were found in tumor tissues and in their derived cell lines and clones. Most of the detected viral genomes were integrated into the cellular DNA, but some tumors also contained free viral DNA sequences. Integration patterns were different from each other, and many different integration sites were available on the cellular or on the viral DNA or on both. Typical features of integration patterns were found in ependymomas, which were the most frequent (72%) among BKV-induced tumors. Readily detectable viral DNA sequences were only found in neoplastic tissues, but traces of BKV DNA were also present in the apparently normal portion of the brain of an animal that had developed an ependymoma and in the brain (but not in the liver) of another animal 15 days after virus inoculation. A cell line and a single-cell clone derived from a tumor had hybridization patterns considerably simpler that the pattern of the original tumor, lacking several integrated viral genomes and all free viral sequences.

Adenoma, Islet Cell↗
PubMed1982

Distribution of ribosomal gene length variants among mouse chromosomes.

The ribosomal genes (rDNA) in mouse inbred strains have a multichromosomal distribution. Using a structural feature of rDNA [variable length rDNA segment (VrDNA)] that shows length polymorphism within and among inbred strains, we studied the chromosomal distribution of the variant ribosomal gene type through genetic analysis. Our results show that five of the length variant classes can be divided into three discrete linkage groups. The variants present on a particular chromosome pair appear to be unique to that pair and absent from nonhomologous chromosomes. The chromosomal location of particular variants appears to be the same in two unrelated inbred strains suggesting that the observed linkage patterns predate the origin of inbred mice. The nonrandom chromosomal distribution of these rDNA classes suggests that only a limited degree of genetic exchange occurs among nucleolus organizer regions on nonhomologous chromosomes. We have localized one particular VrDNA linkage group to chromosome 12. These and other restriction fragment polymorphisms can be used in the construction of detailed mouse linkage maps.

Animals↗
PubMed2000

Quantitative assessment of Hox complex expression in the indirect development of the polychaete annelid Chaetopterus sp.

A prediction from the set-aside theory of bilaterian origins is that pattern formation processes such as those controlled by the Hox cluster genes are required specifically for adult body plan formation. This prediction can be tested in animals that use maximal indirect development, in which the embryonic formation of the larva and the postembryonic formation of the adult body plan are temporally and spatially distinct. To this end, we quantitatively measured the amount of transcripts for five Hox genes in embryos of a lophotrochozoan, the polychaete annelid Chaetopterus sp. The polychaete Hox complex is shown not to be expressed during embryogenesis, but transcripts of all measured Hox complex genes are detected at significant levels during the initial stages of adult body plan formation. Temporal colinearity in the sequence of their activation is observed, so that activation follows the 3'-5' arrangement of the genes. Moreover, Hox gene expression is spatially localized to the region of teloblastic set-aside cells of the later-stage embryos. This study shows that an indirectly developing lophotrochozoan shares with an indirectly developing deuterostome, the sea urchin, a common mode of Hox complex utilization: construction of the larva, whether a trochophore or dipleurula, does not involve Hox cluster expression, but in both forms the complex is expressed in the set-aside cells from which the adult body plan derives.

Animals↗
PubMed2005

Collisional activation by MALDI tandem time-of-flight mass spectrometry induces intramolecular migration of amide hydrogens in protonated peptides.

Considerable controversy exists in the literature as to the occurrence of intramolecular migration of amide hydrogens upon collisional activation of protonated peptides and proteins. This phenomenon has important implications for the application of CID as an experimental tool to obtain site-specific information about the incorporation of deuterium into peptides and proteins in solution. Using a unique set of peptides with their carboxyl-terminal half labeled with deuterium we have shown unambiguously that hydrogen (1H/2H) scrambling is such a dominating factor during low energy collisional activation of doubly protonated peptides that the original regioselective deuterium pattern of these peptides is completely erased (Jørgensen, T. J. D., Gårdsvoll, H., Ploug, M., and Roepstorff, P. (2005) Intramolecular migration of amide hydrogens in protonated peptides upon collisional activation. J. Am. Chem. Soc.127, 2785-2793). Taking further advantage of this unique test system we have now investigated the influence of the charge state and collision energy on the occurrence of scrambling in protonated peptides. Our MALDI tandem time-of-flight experiments clearly demonstrate that complete positional randomization among all exchangeable sites (i.e. all N- and O-linked hydrogens) also occurs upon high energy collisional activation of singly protonated peptides. This intense proton/deuteron traffic precludes the use of MALDI tandem time-of-flight mass spectrometry to obtain reliable information on the specific incorporation pattern of deuterons obtained during exchange experiments in solution.

Amides↗
PubMed2001

Species- and sex-specific renal cytotoxicity of ochratoxin A and B in vitro.

Four different cell models were chosen for comparison of OTA and OTB toxicity: primary porcine (PKC), rat (RPTC) and human renal proximal epithelial cells (HKC) from both sexes and a porcine renal cell line: LLC-PK1. Culture conditions were tested and optimized for each respective cell type (species/sex and origin). All cell types were characterized for epithelial origin and growth patterns and following optimization of dosing strategies and assay procedures, a strict study design was implemented to avoid systemic variations. Due to possible sensitivity differences, three simple endpoints were chosen to provide basic data for interspecies comparison: neutral red uptake, MTT reduction and cell number. Of the endpoints tested neutral red appeared the most sensitive, although all three parameters yielded comparable EC50's. Sex-differences were observed between male and female HKC cells following 96 h exposure to OTA, with HKC(m) being more sensitive than HKC(f). No sex-difference was observed in PKC cells, however, the PKC were approximately 3 and 10 times more sensitive than HKC(m) and HKC(f), respectively, to OTA and OTB. Interestingly, the CI95 of the EC50 values obtained for OTA (15.5-16.5 microM) and OTB (17.0-2 1.0 microM) were comparable in the PKC cells. In contrast, OTB had lower cytotoxicity than OTA in HKC and LLC-PK1 (approx. 2-fold) and no effects in RPTC. Overall, HKC(m) were nearly as sensitive as PKC towards OTA, followed by RPTC, LLC-PK1 and HKC(f), thus suggesting a sex specific sensitivity in humans towards OTA induced cytotoxicity.

Animals↗
PubMed1991

Diabetic neuropathy. Helping patients cope with their pain.

Diabetic neuropathy may have a metabolic or an ischemic origin, and the pattern of nerve damage varies by cause. Treatment should address the underlying cause. Patient reassurance, relaxation techniques, glucose control, use of tricyclic antidepressants or anticonvulsants, and surgical decompression for entrapment neuropathy are currently the mainstays of treatment. Physicians must reassure these patients that neuropathic pain is temporary.

Analgesics, Opioid↗
PubMedDate not supplied

Wrinkles induced by the use of smoothing procedures applied to serial growth data.

This paper elucidates the effects of moving average filters when applied to serial growth measurements. This is a question of interest because smoothing procedures are inherently part of a number of analytical methods presently employed in auxological analyses. Particular attention is paid to sequential growth data analysed to identify what has been described as pulsatile, saltation and stasis patterns or mini-growth spurts. When applied to pulsatile, or saltatory, time series data the process of smoothing itself creates artifactual temporal patterns in the time series data similar to previously described mini growth spurts while removing the actual pulsatile characteristics of the data. These observations illustrate that smoothing approaches add noise to time series data while removing meaningful patterns in the original data sequence. Analyses employing such approaches produce results that include waveforms or other fluctuations compatible with an underlying pulsatile driving mechanism, but do not necessarily reflect the temporal characteristics of the original biological process.

Biometry↗