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Biomedical subjects

B Weber

Publications and source records attributed to B Weber.

At least 343 records · Page 19Linked to original sources
PubMed1988

Modulation by palmitoyl-carnitine of calcium activated, phospholipid-dependent protein kinase activity and inhibition of melanoma cell growth.

Phospholipid-sensitive, Ca++-dependent protein kinase activity was investigated in the cytosol of melanoma cells. A protein kinase system was partially purified, and enzyme activity was found to be modulated by palmitoyl-carnitine. In order to link the actions of palmitoyl-carnitine on phospholipid-sensitive protein kinase activity and the already reported role of protein kinase C in cell division, we studied the action of palmitoyl-carnitine on melanoma cell growth by measuring colony forming ability in a soft agar culture system. Palmitoyl-carnitine was found to inhibit cell growth in a dose-dependent manner. These findings suggest that palmitoyl-carnitine (or long-chain acylcarnitine), a naturally occurring metabolite, may play a key role in the onset of cell division. We suggest that the action of palmitoyl-carnitine on phospholipid-dependent protein kinase activity is in part related to the molecular events linking protein kinase C activity and the ionic events in the initiation of cell growth.

Adult↗
PubMed1988

Long-term monitoring of treatment with recombinant human growth hormone by serial determinations of type III procollagen-related antigens in serum.

Inasmuch as recombinant human growth hormone is now more generally available for the treatment of different types of short stature, there is a need for better short-term indicators of treatment success. In healthy children, serum concentrations of antigens related to the aminoterminal propeptide of type III procollagen (P-III-NP) closely follow the growth velocity curve. P-III-NP was measured longitudinally in 20 children with growth hormone deficiency during 6 months of human growth hormone substitution therapy. Two different radioimmunoassay systems were used; one recognizes predominantly the intact propeptide showing a lesser affinity to a smaller monomeric peptide (RIAgnost assay), while the other assay detects both forms equally (FAB assay). These results were compared to the growth response [median 5.6 (0.4 to 13.9) cm in 6 months] and to other established growth correlated parameters (somatomedin C, alkaline phosphatase). A relatively better growth response correlated significantly with high pretreatment P-III-NP (RIAgnost assay) values (r = 0.56) and delayed bone age (r = -0.70). A combination of these parameters in multiple regression analysis increased the cumulative prediction value to above 60% (r2 = 0.61). On the other hand, P-III-NP (FAB assay) values proved to be best in monitoring treatment, correlating with the individual growth rate during the first 3 months (r = 0.40; p less than 0.05), during the consecutive 3 months (r = 0.66; p less than 0.001), and during the total 6-month period (r = 0.46; p less than 0.05). All other parameters showed associations to growth only during some treatment periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Compliance--a joint effort of the patient and his doctor.

Non-compliance is the reason why in 25-50% of cases treatment of seizures is only partially successful. We have tried to throw some light on the reasons for noncompliance in the behaviour of the doctor as well as the patient. It is not possible simply to prescribe compliance - even though the result is a decrease in attacks; reliability must be learnt. Responsible patients and compassionate doctors are a pre-condition for reliability. Both doctor and patient are committed to treating and healing. This can only be achieved by mutual trust and understanding. A doctor who can make clear to his patient that he is dependent on the patient's co-operation will be more successful than a doctor who does not. Self-help groups can help the patient to recognise his difficulties and take responsibility for himself by coming to terms with his illness. Self-help groups cannot produce compliance; compliance is a result of group work. The doctor - patient relationship has been the subject of much thought, discussion and theorizing recently. In all of this compliance is the key factor.

Anticonvulsants↗
PubMed1988

Amphetamine injection into the ventral mesencephalon sensitizes rats to peripheral amphetamine and cocaine.

The daily administration of indirect dopamine agonists, including amphetamine and cocaine, results in a progressive increase in the behavioral stimulant effect of these drugs. Behavioral augmentation also has been shown with opioids such as morphine, and it is known that a stimulant action on dopaminergic perikarya in the ventromedial mesencephalon is critical to the development of behavioral sensitization to morphine. To determine if amphetamine-induced behavioral sensitization might also involve the mesencephalic dopamine neurons, amphetamine was microinjected daily for 2 days into regions of the rat brain containing dopamine cell bodies (A10 and A9 dopamine regions), or dopamine terminals (nucleus accumbens and striatum), and 6 days later amphetamine was given peripherally. It was found that daily amphetamine injection into the A10 or A9 dopamine region, but not into the dopamine terminal fields, significantly potentiated the motor stimulant effect of peripherally administered amphetamine. The behavioral sensitization produced by intracranial injection of amphetamine was found to be dose-dependent. Intra-A10 injection of amphetamine also was found to potentiate the motor stimulant effect of peripheral cocaine. These data indicate that an action by amphetamine in the A10 and A9 dopamine regions may play a critical role in the development of behavioral sensitization.

Amphetamine↗
PubMed1987

Sensitive and selective determination of picogram amounts of ciprofloxacin and its metabolites in biological samples using high-performance liquid chromatography and photothermal post-column derivatization.

An analytical method for the detection and quantification of ciprofloxacin and its known metabolites M1, M2, M3 and M4 in urine, serum/plasma, bile, faeces and tissue is described. For the liquid matrices the only sample preparation that is required is dilution. The assay consists of reversed-phase high-performance liquid chromatography and fluorescence detection. For the metabolites M2, M3 and M4 an additional post-column derivatization by successive thermolysis and photolysis is needed. A suitable simple post-column reactor has been constructed. Detection limits for all compounds are between 0.2 and 2.2 ng/ml (absolute detection limits 2-22 pg). Compared with fluorescence detection alone, the derivatization increases the selectivity of detection significantly. The linearity, precision and accuracy of the method were determined.

Bile↗
PubMed1987

A Y/5 translocation in a 45,X male with cri du chat syndrome.

In a patient described as a 45,X male with cri du chat syndrome, combined cytogenetic and molecular methods revealed Y euchromatic material to be translocated onto the short arm of one chromosome 5, resulting in a chromosome der(5)(5qter----5p14::Yp11.31----Ypter). The translocated Y euchromatin comprised only the distal short arm including the pseudoautosomal region and the so-called deletion intervals 1 and 2. A review of 45,X males from the literature showed that; most of them carry a paternally transmitted Y/autosome translocations; resulting in various autosomal deletions. Depending on the segment concerned, the deletion led to congenital malformations.

Chromosome Banding↗
PubMed1987

Conservation of human-derived pseudoautosomal sequences on the sex chromosomes of the great apes.

In situ hybridization using a repeated element specific for the human pseudoautosomal region, DXYZ2, revealed the presence of this repeat in the early replicating portion of the sex chromosomes of the great apes. This segment, as well as the DXYZ2 repeats, are located in band Xp22.3 and in a telomeric or subtelomeric region of the Y chromosome. These segments may therefore represent pseudoautosomal regions, as in man.

Animals↗
PubMed1987

Iodine in contrast agents and skin disinfectants is the major cause for hypothyroidism in premature infants during intensive care.

In 51 sick newborns the influence of two different nonionic, iodine-containing contrast agents, Amipaque (group 1) and Omnipaque (group 2) and of long-term treatment with polyvinylpyrrolidone-iodine (PVP-I) (group 3) on thyroid function was studied. In the dose given, freshly dissolved Amipaque releases roughly 100 micrograms 'free' iodide/kg body weight; this release may be even higher in the solubilized agent Omnipaque because of increased breakdown. Urinary iodine excretion was elevated in all groups on day 5 after iodine exposure. In group 1, which included 17 term newborns, the median TSH level was normal after 5 days and 2 weeks, only 1 case of transient hypothyrotropinemia was observed; T4 and T3 median levels were in the lower range of normal. In groups 2 and 3, which included 8 preterm infants of 15 newborns and 9 preterm infants of 19 newborns, respectively, the median TSH values were elevated and T4 and T3 levels were very low. Hypothyroidism was diagnosed in 6 of the 8 preterm and in 1 of the 7 term newborns of group 2. In group 3, 7 of the 9 preterm and 3 of the 10 term newborns reacted with hypothyroidism. Eight preterm and 3 term newborns had to be substituted with thyroxine. The thyroid function of term newborns was less affected by Amipaque or Omnipaque than by PVP-I. The data show that preterm infants are very sensitive to an iodine load.

Contrast Media↗
PubMed1987

Single-dose investigation of possible interactions between the components of the antimalarial combination Fansimef.

Fansimef is a new oral schizonticide which contains pyrimethamine (P), sulfadoxine (S) and mefloquine (M) in a weight ratio of 1:20:10. This antimalarial combination is highly active against multi-resistant Plasmodium falciparum and in vitro studies showed that the resistance development by plasmodia against this combination is considerably delayed. The single-dose pharmacokinetics of the three Fansimef components were investigated in 10 Caucasian volunteers with special emphasis on possible mutual kinetic interactions. For this reason the same subjects received successively tablets of Fansimef (P + S + M), Fansidar (P + S) and mefloquine alone. Following administration of Fansimef all three components revealed long elimination half-lives (P = 88 h, S = 183 h, M = 437 h) and high binding to plasma proteins (P = 92.5%, S = 87.6%, M = 97.6%). The apparent volume of distribution in the postdistributive phase (VD beta/F) was small for S (0.13 l/kg) but amounted to 2.1 l/kg for P and reached even 11.8 l/kg in the case of M. The systemic clearance (ClTS/F) showed almost identical values for P and M, namely approximately equal to 19 ml/h/kg, while sulfadoxine reached only a value of 0.5 ml/h/kg. Almost identical pharmacokinetic parameters (p greater than 0.05) were found after administration of Fansidar or M alone. Therefore one can exclude any significant interaction between the single components of the Fansimef combination. In addition, animal studies showed that synergism of the toxicity of the three combination partners can be excluded.

Adult↗
PubMed1987

[Pseudolinitis plastica of breast origin].

The most common type of gastric metastases secondary to carcinoma of the breast is the one showing a linitis plastica appearance. The roentgenologic aspect when performing an upper gastrointestinal examination with barium contrast is typical and allows the differential diagnosis with the primitive linitis. The linitis plastica type of metastatic breast carcinoma results from transmural infiltration of the stomach wall with initial deposit of tumor cells in the submucosal or subserosal regions. CT provide valuable information concerning the metastatic spread.

Adenocarcinoma, Scirrhous↗