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Biomedical subjects

G Just

Publications and source records attributed to G Just.

At least 19 recordsLinked to original sources
PubMed2002

Radon progeny activity on skin and hair after speleotherapeutic radon exposure.

The objective of present investigation was to measure radon progeny activity on hair and skin (forehead, paraumbilical, paravertebral) and its decrease after speleotherapeutic radon exposure in the gallery of the Gasteiner Heilstollen. Radon progeny activity was measured by means of a halogen-quenched Geiger-Mueller tube with a mica window (density 1.5-2.0 mg/cm2) and an effective diameter of 45 mm; beta efficiency 32% (210Bi), alpha efficiency 18% (241Am). Results are in counts per minute (cpm). All 17 patients were being treated for rheumatic disease in the galleries of the Gasteiner Heilstollen Hospital. The following activity (mean +/- standard error of the mean) was measured 25 (+/- 5) min after leaving the treatment area: on hair of the head, 1235+/-141 cpm; forehead, 503+/-78 cpm; paraumbilical 460+/-85 cpm; paravertebral, 270+/-39 cpm. Taking a shower did not significantly reduce radon progeny activity. Speleotherapeutic radon exposure causes a considerable increase in radon progeny activity on skin. The large surface of hair causes much greater activity on hair than on skin. Owing to their high adhesive properties, radon progenies are not reduced by taking a shower.

Hair↗
PubMed2000

Spanning or looping? The order and conformation of bipolar phospholipids in lipid membranes using 2H NMR spectroscopy.

Solid-state 2H NMR spectroscopy was used to study and characterize the conformation and order of bolaform lipid membranes. A series of 2H-labeled bolaform phosphatidylcholines has been synthesized and their properties compared to a [D4]dimyristoylphosphatidylcholine (DMPC) and a [D8]-32 macrocyclic phosphatidylcholine. 31P NMR measurements establish that the aqueous dispersions of these lipids adopt lamellar phases. Computational dePakeing was used to extract the spectrum of the oriented system from spectra consisting of a superposition of randomly oriented domains in an unoriented sample. A large (> 90 %) and constant value for the normalized segmental order parameter (Smol) was observed for all positions along the diacyl chain of the bolaform lipids and only a small population (< 10%) of a less ordered conformer was observed. The less ordered conformer is assigned to the looping conformation on the basis of comparison with the deuterated macrocyclic phospholipid which has an enforced loop in its diacyl chain. The predominant population(> 90%) of the bolaform lipids is assigned to a highly ordered, spanning conformer.

Deuterium↗
PubMed2000

Allyl group as a protecting group for internucleotide phosphate and thiophosphate linkages in oligonucleotide synthesis: facile oxidation and deprotection conditions.

[reaction: see text] The allyl group, which serves as a protecting group for an internucleotide bond for both phosphates and phosphorothioates, can be easily removed by good nucleophiles under weakly basic or neutral conditions. For a practical synthesis on solid support, camphorsulfonyloxaziridine was used as the oxidizing agent for synthesizing DNA, while the Beaucage reagent was used for preparing phosphorothioate oligomers. Both types of oligonucleotides were easily deprotected by concentrated ammonium hydroxide containing 2% mercaptoethanol.

Acetylene↗
PubMed2000

Radon progeny activity in sweat following radon exposure in a warm and humid environment.

The objective was to evaluate whether activity of radon progenies can be detected in sweat following speleotherapeutic radon exposure (40 kBq/m3) in a warm (38 degrees C) and humid (relative humidity > 70%) environment. A group of 11 male patients with spondyloarthropathy (n = 6) or non-inflammatory rheumatic diseases (n = 5) underwent a 1-h treatment in the gallery of the Gasteiner Heilstollen, and 20 min after leaving the treatment area radon progeny activity was measured in sweat by utilizing a special filter set. The results suggest that radon is discharged with sweat, causing a significant activity of radon and radon progenies on the skin. This finding may be important from a clinical point of view, since specialists experienced in radon therapy have repeatedly emphasized the importance of the degree of radioactivity on the skin for the effectiveness of treatment. It has even been claimed that the skin is the major target for radon therapy, possibly because of the influence on Langerhans' cell function.

Fever↗
PubMed2000

[Dynamics of radon decay product activity in saliva following therapeutic radon exposure].

Radon decay product activity was measured in saliva of 10 male patients 20-30 min after a 1-hour radon exposure in the gallery of the Gasteiner Heilstollen (radon activity 36.2 kBq/m(3), radon progeny activity 20.3 kBq/m(3)). In 1 patient showing relatively high activity (75th percentile) measurements were continued until 65 min after exposure. Patients were asked to collect about 2 ml of saliva in the mouth and produce it on a filter. After drying the filter at 300 degrees C, radon progeny activity was measured. Activity (median) at 20-30 min after leaving the treatment area was 4.5 Bq (25th percentile 1 Bq; 75th percentile 21 Bq). In the patient who underwent additional measurements the activity showed a further increase up to 29 Bq (35 min after radon exposure) before it continuously decreased to a very low activity (1-3 Bq) at 65 min after exposure. The results show that a significantly increased radon decay product activity is found in saliva after speleotherapeutic radon exposure. Maximum values were observed 35 min after radon exposure. Radon decay product activity almost disappeared after about 1 h.

Complementary Therapies↗
PubMed1996

Susceptibilities of Candida spp. to antifungal agents visualized by two-dimensional scatterplots of relative growth.

The growth of 811 clinical yeast isolates in the presence of single concentrations of antifungal agents was measured spectrophotometrically and expressed as a percentage of growth in inhibitor-free control cultures. Two-dimensional scatterplots of the relative growth data allowed for the simple visual determination of some susceptibility trends, including correlations in relative growth between different agents and in relative susceptibilities between different yeast species. A positive susceptibility correlation was found for relative growth results with the azole antifungal agents fluconazole, itraconazole, and ketoconazole for 504 Candida albicans isolates. The relative growth scatterplots for fluconazole versus itraconazole showed that 50 (9.9%) of 504 C. albicans isolates were outliers with respect to the 95% confidence limits for a line of correlated relative growth established with an initial test panel of 59 isolates of this species. The outlying isolates were relatively less susceptible to fluconazole than to itraconazole under the conditions of the test. Most of the outliers were received in 1993 and 1994; only 3.9% of the isolates received in 1991 and 1992 and 1.7% of the isolates received before 1991 showed this differential susceptibility. In addition, most of the outliers came from patients with human immunodeficiency virus infections. The relative growth scatterplots confirmed the known high susceptibility of most Candida parapsilosis isolates to both fluconazole and itraconazole and the specifically low susceptibility of Candida krusei isolates to fluconazole. The scatterplots also illustrated a tendency towards lower (and correlative) relative growth among oral isolates obtained from AIDS patients who responded to azole antifungal treatment than among isolates from clinical nonresponders.

AIDS-Related Opportunistic Infections↗
PubMed1996

Visceral leishmaniasis emerging as an important opportunistic infection in HIV-infected persons living in areas nonendemic for Leishmania donovani.

BACKGROUND: Visceral leishmaniasis is an important infection in patients infected with human immunodeficiency virus and living in areas endemic for Leishmania sp. Leishmaniasis, however, is rarely suspected in patients residing in nonendemic countries. METHODS: Retrospective case analysis of 15 patients with human immunodeficiency virus infection and leishmaniasis treated at seven German clinics. The clinicopathological features and the diagnostic role of biopsy and/or cytology as compared to serology were evaluated. RESULTS: All patients were severely immunocompromised. One patient was first diagnosed at autopsy. One patient with mucocutaneous disease was diagnosed by nasal biopsy. All others had amastigotes detected in bone marrow (13/13), liver (3/3), and gastrointestinal mucosa (4/4). Serology was positive in only 6 or 13. CONCLUSION: Visceral leishmaniasis is an important opportunistic infection in patients with acquired immunodeficiency syndrome and it must be ruled out in every patient with fever and/or pancytopenia and an appropriate travel history. Because serological diagnosis is often insufficient, pathologists must be aware of the association between human immunodeficiency virus infection and leishmaniasis. Diagnosis depends on detection of the parasite in submitted specimens.

AIDS-Related Opportunistic Infections↗
PubMed1995

Structural basis for the RNA binding selectivity of oligonucleotide analogues containing alkylsulfide internucleoside linkages and 2'-substituted 3'-deoxyribonucleosides.

In this report we describe the synthesis of oligonucleotides containing sulfide-linked dinucleoside units, namely rT(2'OH)sdT, rT(2'OMe)sdT, dTsrU(2'OMe) and dT(2'OMe)srU(2'OMe). We also describe the interactions of such oligomers with complementary DNA and RNA targets, and provide the structural basis for their remarkable RNA binding selectivity. In all cases, the Tm values of the S/P-chimera duplexes were lower than those of the corresponding unmodified duplexes. We attribute this to steric interactions between the 5'sulfur and the atoms of the nearby base/sugar residues. The 2'-substituents (i.e., 2'OH or 2'OMe) vicinal to the alkylsulfide internucleoside linkage significantly perturb the structure and stability of the duplexes formed with DNA, and more so than with RNA. The introduction of three rT(2'OH)sdTp (or rT(2'OMe)sdTp) units into an oligodeoxynucleotide sequence was sufficient to abolish binding to complementary DNA but not RNA. The same three substitutions with dTsrU(2'OMe)p and dT(2'OMe)srU(2'OMe)p did not abolish binding to DNA but the resulting complexes had poor thermal stability. The RNA-binding 'selectivity' exhibited by these oligomers is attributed to the tendency of the 2'-substituted (branched) furanoses to adopt the C3'-endo pucker, a conformation that is inconsistent with the B-form structure of helical DNA. The preference of these sugars to exist often exclusively in the C3'-endo form is attributed to stereoelectronic effects, namely gauche and anomeric effects. Our findings support the hypothesis that nucleoside analogues puckered exclusively in the C3'-endo form may result in them being especially good binders of targeted mRNA [S.H. Kawai (1991), Ph.D. Thesis, McGill University; Kawasaki et al. (1993) J. Med. Chem. 36, 831-841].

Base Sequence↗
PubMed1993

Solid-phase synthesis and hybridization properties of DNA containing sulfide-linked dinucleosides.

Oligodeoxyribonucleotides incorporating non-hydrolyzable dialkyl sulfide linked thymidine dimers (TsT) were synthesized chemically by the solid-phase approach. The sulfide dimer TsT was stable to degradation by snake-venom phosphodiesterase, calf spleen phosphodiesterase, Nuclease P1 and Nuclease S1. Thermal denaturation analysis indicated that the incorporation of TsT dimers into DNA weakened, but did not prevent, binding to complementary DNA and RNA over a wide range of salt concentrations (10 mM to 2 M NaCl).

Base Sequence↗
PubMed1993

Organ donation: comparison of nurses' participation in two states.

BACKGROUND: The number of organs available for transplantation in the United States is insufficient, and the donor rate in New Jersey is particularly low. OBJECTIVES: To explore reasons nurses do or do not refer organ donors and to identify factors that contribute to differences in referral rates in New Jersey and Pennsylvania. METHODS: Registered nurses (N = 976) in 57 nongovernmental acute care hospitals, primarily in emergency departments and intensive care units, completed a questionnaire that focused on their knowledge and participation in the organ procurement process. RESULTS: Two-thirds of the subjects said they had participated in organ procurement. Pennsylvania nurses had a significantly higher involvement rate than New Jersey nurses. Pennsylvania nurses were also slightly more knowledgeable about the process. A higher proportion of nurses in both states who attended continuing education programs participated. CONCLUSIONS: Nurses need more inservice education regarding policies and procedures for organ donation.

Adult↗
PubMed1992

Studies on anabolic steroids. 9. Tertiary sulfates of anabolic 17 alpha-methyl steroids: synthesis and rearrangement.

A simple and convenient method has been developed to prepare sulfates of anabolic 17 beta-hydroxy-17 alpha-methyl steroids. The sulfates of methandienone, 17 alpha-methyltestosterone, mestanolone, oxandrolone, and stanozolol were prepared. Different A-ring functions were not affected under the sulfation condition. The buffered hydrolyses of these sulfates provided the 17-epimers of the original steroids and 17,17-dimethyl-18-nor-13(14)-ene steroids, presumably via the 17-carbocations.

Anabolic Agents↗
PubMed1992

Studies on anabolic steroids. 10. Synthesis and identification of acidic urinary metabolites of oxymetholone in a human.

Two major unconjugated acidic metabolites of oxymetholone (17 beta-hydroxy-2-hydroxymethylene-17 alpha-methyl-5 alpha-androstan-3-one, 1), namely, 17 beta-hydroxy-17 alpha-methyl-2,3-seco-5 alpha-androstane-2,3-dioic acid (2) and 3 alpha,17 beta-dihydroxy-17 alpha-methyl-5 alpha-androstane-2 beta-carboxylic acid (6a), were detected by gas chromatography/mass spectrometry in urine samples collected after oral administration of 1 to a human volunteer. Reference steroid 2 was synthesized and identified. The identification of urinary metabolite 6a was based on the synthesis of its stereoisomers and the isomerization of the methyl ester 6b to its 2-epimer, 3 alpha,17 beta-dihydroxy-17 alpha-methyl-5 alpha-androstane-2 alpha-carboxylic acid methyl ester (9b). The mechanisms accounting for the formation of these acidic metabolites are discussed.

Acids↗
PubMed1991

Enhanced levels of cyclic AMP, adenosine(5')tetraphospho(5')adenosine and nucleoside 5'-triphosphates in mouse leukemia P388/D1 after treatment with cis-diamminedichloroplatinum(II).

As part of the exploration of the mechanism of platinum(II) complex-induced growth inhibition and/or cytotoxicity, we studied the intracellular levels of several nucleotides during treatment of mouse leukemia P388/D1 at selected concentrations of 1 microM cis-diamminedichloroplatinum(II) (cis-DDP) and 20 microM of its trans-isomer (trans-DDP). The effects and their time-dependences are correlated with those on cell growth parameters previously published (Just G and Holler E, Cancer Res 49: 7072-7078, 1989). The effects of cis-DDP are strong and irreversible, whereas those of trans-DDP are marginal and reversible, in parallel with similar effects on cell growth parameters. Concentrations of nucleoside 5'-di- and 5'-triphosphates increase in parallel with cellular DNA and protein content by three- to four-fold after 60 hr of treatment. The nucleoside monophosphates dAMP, dGMP and dTMP reveal concentration maxima during exponential cell growth that are two- to six-fold higher than in the control cultures. Levels of cyclic AMP, adenosine(5')tetraphospho(5')adenosine (Ap4A) and CDP rise three- to five-fold above those in the control cultures within a few hours of the start of treatment. The level of coenzyme NAD+ falls below that of the control, concomitantly with an arrest of cells in the G2 phase of the cell cycle and with the appearance of giant cells. Due to the high reactivity of cis-DDP and the continuous concentration increase during the treatment, purine nucleoside 5'-triphosphates provide a possibility for the acquisition of resistance to cis-DDP. The correlation of responses of metabolically and regulatory active nucleotides with biological effects suggests their function in antitumorigenesis.

Adenosine Triphosphate↗
PubMed1989

Platinum incorporation and differential effects of cis- and trans-diamminedichloroplatinum(II) on the growth of mouse leukemia P388/D1.

The parallel effects of cis-diamminedichloroplatinum(II) (1 microM) or trans-diamminedichloroplatinum(II) (20 microM) on the growth of mouse leukemia P388/D1 in culture, on the cellular content of protein/DNA, on the average cell volume, and on the distribution in different phases of the cell cycle were measured over a period of 70 h and compared with the amount of platinum residing in the cells. Despite different concentrations in the culture medium, similar amounts of cis- and trans-diamminedichloroplatinum(II) were incorporated. The platinum content of cells passed through an early concentration maximum in the millimolar range and decreased during prolonged times of incubation. Effects of cis-diamminedichloroplatinum(II) were marked and irreversible whereas those of trans-diamminedichloroplatinum(II) were small and transient. Proliferation was inhibited, while synthesis of protein and DNA continued almost unaffected. Cells were arrested in G2-phase of the cell cycle, and their volume increased correspondingly. The results suggested an inhibition of mitotic events, rather than of DNA replication, that caused cell arrest.

Animals↗
PubMed1989

Change of causative organisms under antifungal treatment in immunosuppressed patients with HIV-infections.

Oral and esophageal candidosis are very common in HIV-infected patients. Due to the lack of efficacy of topical antimycotics in advanced stages of HIV-infection oral azoles are mainly used for treatment. Azoles most often used are ketoconazole and fluconazole. While Candida albicans clearly is the most frequently encountered yeast before and after treatment other species can be found somewhat less frequently after treatment. This especially applies to Candida glabrata. Candida spp. other than C. albicans obviously may cause manifest oral candidosis. This shift of microbes deserves the more interest as they are less susceptible to azole drugs.

Antifungal Agents↗