Biomedical subjects

J Roth

Publications and source records attributed to J Roth.

At least 127 records · Page 7Linked to original sources

PubMed1995

Uterine vascularity during stimulation and its correlation with implantation in in-vitro fertilization.

The changes in uterine artery blood flow in women undergoing in-vitro fertilization cycles were studied throughout stimulation after gonadotrophin-releasing hormone (GnRH) desensitization. The data obtained showed that the uterine vascularity was related to hormonal changes. The GnRH agonist effect was seen only after the third week of administration, and the uterine perfusion was significantly (P = 0.002) improved by the oestradiol secretion. Human chorionic gonadotrophins increased the resistance index (RI) significantly (P = 0.0001) for a period of 48 h. Then the progesterone secretion modified the curve with a significant improvement in the uterine blood flow (P = 0.03). Comparison of the RI value 2 days before human menopausal gonadotrophin (HMG) commencement, in patients with and without pregnancy, showed a higher RI in patients who did not conceive but no difference was observed on the day of embryo transfer. The pregnancy rates were similar whatever the range of the RI observed. The data available so far suggest that haemodynamic parameters alone, detected by Doppler sonography, do not provide full information on endometrial receptivity on the day of embryo transfer. A resistance index > 0.79 before HMG commencement seems to indicate poor uterine vascularity and may necessitate an increase in the HMG doses to prevent endometrial immaturity.

Adult↗

PubMed1995

Five promoters integrate control of the cob/pdu regulon in Salmonella typhimurium.

Propanediol is degraded by a B12-dependent pathway in Salmonella typhimurium. The enzymes for this pathway are encoded in a small region (minute 41) that includes the pdu operon (controlling B12-dependent degradation of propanediol) and the divergent cob operon (controlling synthesis of cobalamin, B12). Expression of both operons is induced by propanediol and globally controlled by the ArcA and Crp systems. The region between the two operons encodes two proteins, PduF, a transporter of propanediol, and PocR, which mediates the induction of the regulon by propanediol. Insertion mutations between the pdu and cob operons have been characterized, and their exact positions have been correlated with mutant phenotypes. The region includes five promoters, four of which are controlled by the PocR protein and induced by propanediol. The cob and pdu operons each have one regulated promoter; the pduF gene is expressed from two regulated promoters (P1 and P2). The P1 and P2 transcripts extend beyond pduF to include the pocR gene; thus the PocR protein autoregulates its expression from these promoters. The fifth promoter, PPoc, is adjacent to the pocR gene and associated with a Crp binding site. We suggest that all global control of the regulon is exerted by regulating the level of PocR protein at the P1, P2, and PPoc promoters. A putative binding site for the PocR protein has been identified by computer analysis. Eight close matches to this proposed site were found in regions near the four promoters known to be regulated by PocR protein: PPdu, P1, P2, and PCob. A three-state model is proposed in which the regulon uses all five of its promoters to control expression.

Bacterial Outer Membrane Proteins↗

PubMed1995

Isolation of NAD cycle mutants defective in nicotinamide mononucleotide deamidase in Salmonella typhimurium.

The NAD or pyridine nucleotide cycle is the sequence of reactions involved in the breakdown of NAD to nicotinamide mononucleotide (NMN) and regeneration of NAD. This cycle is fivefold more active during aerobic growth of Salmonella typhimurium and under this condition breaks down half of the NAD pool every 90 min. DNA ligase is known to convert NAD to NMN but is only a minor contributor to the NAD cycle during aerobic growth. The dominant aerobic route of NMN formation is otherwise uncharacterized. Accumulated NMN generated by either of these routes is potentially dangerous in that it can inhibit the essential enzyme DNA ligase. The reactions which recycle NMN to NAD may serve to minimize the inhibition of ligase and other enzymes by accumulated NMN. The predominant recycling reaction in S. typhimurium appears to be NMN deamidase, which converts NMN directly to the biosynthetic intermediate nicotinic acid mononucleotide. Mutants defective in this recycling step were isolated and characterized. By starting with a ligase-deficient (lig mutant) parent strain that requires deamidase to assimilate exogenous NMN, two classes of mutants that are unable to grow on minimal NMN media were isolated. One class (pncC) maps at 83.7 min and shows only 2% of the wild-type levels of NMN deamidase. Under aerobic conditions, a lig+ allele allows a pncC mutant to grow on NMN and restores some deamidase activity. This growth ability and enzyme activity are not found in lig+ strains grown without oxygen. This suggests that the existence of a second NMN deamidase (pncL) dependent on ligase and stimulated during aerobic growth. The second class of mutants (pncD) gains a requirement for isoleucine plus valine with growth in the presence of exogenous NMN. We propose that pncD mutations reduce the activity of an ilv biosynthetic enzyme that is naturally sensitive to inhibition by NMN.

Amidohydrolases↗

PubMed1995

The end of the cob operon: evidence that the last gene (cobT) catalyzes synthesis of the lower ligand of vitamin B12, dimethylbenzimidazole.

The cob operon of Salmonella typhimurium includes 20 genes devoted to the synthesis of adenosyl-cobalamin (coenzyme B12). Mutants with lesions in the promoter-distal end of the operon synthesize vitamin B12 only if provided with 5,6-dimethylbenzimidazole (DMB), the lower ligand of vitamin B12. In the hope of identifying a gene(s) involved in synthesis of DMB, the DNA base sequence of the end of the operon has been determined; this completes the sequence of the cob operon. The cobT gene is the last gene in the operon. Four CobII (DMB-) mutations mapping to different deletion intervals of the CobII region were sequenced; all affect the cobT open reading frame. Both the CobT protein of S. typhimurium and its Pseudomonas homolog have been shown in vitro to catalyze the transfer of ribose phosphate from nicotinate mononucleotide to DMB. This reaction does not contribute to DMB synthesis but rather is the first step in joining DMB to the corrin ring compound cobinamide. Thus, the phenotype of Salmonella cobT mutants conflicts with the reported activity of the affected enzyme, while Pseudomonas mutants have the expected phenotype. J. R. Trzebiatowski, G. A. O'Toole, and J. C. Escalante Semerena have suggested (J. Bacteriol. 176:3568-3575, 1994) that S. typhimurium possesses a second phosphoribosyltransferase activity (CobB) that requires a high concentration of DMB for its activity. We support that suggestion and, in addition, provide evidence that the CobT protein catalyzes both the synthesis of DMB and transfer of ribose phosphate. Some cobT mutants appear defective only in DMB synthesis, since they grow on low levels of DMB and retain their CobII phenotype in the presence of a cobB mutation. Other mutants including those with deletions, appear defective in transferase, since they require a high level of DMB (to activate CobB) and, in combination with a cobB mutation, they eliminate the ability to join DMB and cobinamide. Immediately downstream of the cob operon is a gene (called ORF in this study) of unknown function whose mutants have no detected phenotype. Just counterclockwise of ORF is an asparagine tRNA gene (probably asnU). Farther counterclockwise, a serine tRNA gene (serU or supD) is weakly cotransducible with the cobT gene.

Amino Acid Sequence↗

PubMed1995

Endotoxin tolerance alters thermal response of guinea pigs to systemic infusions of tumor necrosis factor-alpha.

In guinea pigs, intra-arterial infusions of 5 micrograms/kg tumor necrosis factor-alpha (TNF; specific activity 20,000 U/micrograms; duration of infusion 45-50 min) evoked a biphasic elevation of abdominal temperature lasting approximately 6 h. One week after systemic infusion of TNF, the animals started to receive either five intramuscular injections of bacterial lipopolysaccharide (LPS from Escherichia coli; 20 micrograms/kg) or equivalent volumes of solvent (0.9% NaCl) in intervals of 3 days. Fever in response to repeated injections of LPS was progressively attenuated; the animals developed endotoxin tolerance. Repeated injections with solvent did not cause any measurable changes in abdominal temperature. Three days after the fifth injection of LPS or solvent, all animals again received an intra-arterial infusion of 5 micrograms/kg TNF. In guinea pigs injected five times with solvent, the biphasic elevation of abdominal temperature could again be observed in response to systemic infusions of TNF. In endotoxin-tolerant animals, however, only the first peak of the biphasic thermal response lasting approximately 60 min could be monitored after infusions with TNF. The second phase of the thermal response to administration of TNF, which normally lasts > 5 h, was abrogated almost completely. The significant suppression of the febrile response to TNF infusions did not seem to be caused by a more rapid elimination of TNF from the circulation of endotoxin-tolerant guinea pigs. Circulating levels of TNF, measured 60 and 180 min after the start of TNF infusions, were not different before and after development of endotoxin tolerance. In conclusion, the development of endotoxin tolerance in guinea pigs is accompanied by a reduced responsiveness to TNF administered exogenously.

Animals↗

PubMed1995

Production of systemic and hypothalamic cytokines during the early phase of endotoxin fever.

Changes in concentrations of cytokines in plasma and in hypothalamic push-pull perfusates of guinea pigs were measured within the 1st hour after intramuscular injections of bacterial lipopolysaccharide (LPS; Escherichia coli, 20 micrograms/kg) or solvent (0.9% saline). In control animals injected with solvent, interleukin (IL)-1 and tumor necrosis factor alpha (TNF-alpha) were not detectable in plasma. Only IL-6 was present in picogram quantities. Within 45 min after injection of LPS, the concentrations of IL-1, TNF-alpha, and IL-6 increased in the plasma: by several orders of magnitude for TNF-alpha and about tenfold for IL-G. Picogram amounts of biologically active IL-1 were detected in plasma after injection of LPS. No steady state levels of systemic cytokines were reached during the experimental period. In hypothalamic perfusates of animals injected with the solvent, no IL-1 was detectable. TNF-alpha could be detected at higher concentrations than IL-6. IL-6 was detectable at tenfold lower concentrations than in the plasma. In animals injected with LPS, the hypothalamic concentration of IL-6 started to increase during the period 15-30 min and the concentrations of TNF-alpha during the period 30-45 min after LPS injection. The concentrations of IL-6 increased by 300-400% and did not exceed picogram values. No progressive increase of hypothalamic levels of these cytokines was observed during the time course of the experiment. The method used did not detect any changes in the amount of biologically active IL-1 in hypothalamic perfusates of LPS-treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Glucagon-like peptide-1 affects gene transcription and messenger ribonucleic acid stability of components of the insulin secretory system in RIN 1046-38 cells.

It has been previously demonstrated that the enteric hormone glucagon-like peptide-1 (7-36 amide) (GLP-1) has acute effects on glucose-induced insulin secretion by RIN 1046-38 cells. In this study, we investigated the effects of extended exposure of RIN 1046-38 cells to GLP-1 and examine the mechanism by which GLP-1 synergizes with glucose in stimulating insulin secretion. Compared with cells cultured with glucose alone, incubation of cells with glucose plus 1 or 10 nM GLP-1 for 12 or 24 h significantly increased insulin release by about 3-fold, intracellular insulin content by 1.5-fold, and insulin messenger RNA (mRNA) by almost 2.5-fold. The insulinotropic effects of GLP-1 on RIN 1046-38 cells were accompanied by an up-regulation of both glucose transporter-1 (GLUT-1) and hexokinase I mRNA by about 2-fold. mRNA levels of GLUT-2 and glucokinase, which were low in controls, were unchanged by GLP-1 treatment. Treatment of cells with a transcription inhibitor, actinomycin D, demonstrated that elevated insulin mRNA levels after a GLP-1 exposure are mainly due to stabilization of the mRNA. In contrast, the elevated mRNA levels of GLUT-1 and hexokinase I are the result of increased transcription stimulated by GLP-1 exposure. Actinomycin D blunted the GLP-1 effect on insulin release but did not affect GLP-1 mediated elevation of insulin mRNA. This suggests that actinomycin D inhibits the transcription of the proteins necessary for insulin biosynthesis and insulin release, such as GLUT-1 and hexokinase I. Our study suggests that the mechanisms by which extended exposure of RIN 1046-38 cells to GLP-1 increases glucose-stimulated insulin secretion include significant up-regulation of glucose-sensing elements.

Animals↗

PubMed1995

Patterns of evoked otoacoustic emissions associated with acoustic neuromas.

Evoked otoacoustic emissions (OAEs) are assumed to reflect healthy outer hair cell function. Over the past few years, evoked OAEs have been shown to be useful as indicators of cochlear hearing loss. Because basic studies have shown that OAEs are extremely sensitive to cochlear anoxia and hypoxia, as well as to the adverse effects of many inner ear diseases, it is possible that these objective tests can provide some insight into the fundamental basis of the hearing loss exhibited by patients with acoustic neuromas. The primary aim of the present study was to examine the effects of acoustic neuromas on the amplitudes of evoked OAEs and to compare these findings with tumor-induced hearing levels. To this end, tests of behavioral audiometry, distortion-product otoacoustic emissions and transiently evoked otoacoustic emissions were performed on 44 patients with verified acoustic neuromas. The results demonstrated that the majority of ears with acoustic neuromas displayed one of two distinct patterns of evoked OAEs: a cochlear pattern or a noncochlear pattern. Although behavioral hearing thresholds were higher with larger tumors, OAE levels exhibited no clear relationship to tumor size. The present findings support the notion that acoustic neuromas may cause hearing impairment according to two types of influence that act at different levels of the peripheral auditory system. The tumor's cochlear effect on evoked OAE activity is most likely caused by an indirectly mediated compromise of the organ of Corti's vascular supply. It is probable that the direct pressure of the tumor on the eighth cranial nerve is responsible for the observed noncochlear effects.

Audiometry↗

PubMed1995

Absence of RET proto-oncogene point mutations in sporadic hyperplastic and neoplastic lesions of the parathyroid gland.

We investigated the possible role of RET proto-oncogene mutations in the development of sporadic hyperplastic, benign, and malignant parathyroid lesions. DNA extracted from paraffin-embedded specimens of forty parathyroid lesions was screened for RET proto-oncogene point mutations in exons 10, 11, and 16 by nonisotopic polymerase chain reaction-based single-strand conformation polymorphism and heteroduplex gel electrophoresis. The nucleotide sequence of samples with aberrant band patterns was identified by nonisotopic direct sequencing of polymerase chain reaction-amplified DNA. Parathyroids of seven patients with multiple endocrine neoplasia type 2A (MEN 2A) and MEN 2B served as positive controls. None of the eight hyperplastic lesions, three cases of parathyromatosis, ten parathyroid adenomas, eleven carcinomas or one normal parathyroid gland contained mutations in each of the three RET exons tested. Six MEN-2A-associated hyperplastic glands exhibited identical band shifts in the polymerase chain reaction single-strand conformation polymorphism analysis of exon 11, which corresponded to a Cys 634-->Arg substitution in the nucleotide sequence analysis (TGC-->CGC), whereas in the MEN 2B parathyroid specimen a point mutation was found at codon 918 of exon 16 (ATG-->ACG), causing a Met 918-->Thr substitution. Our data indicate that RET mutations of the MEN 2 loci in exons 10, 11, and 16 are not involved in the development of sporadically occurring benign or malignant parathyroid lesions. Furthermore, our results are in accordance with the observation that MEN 2A patients with Cys 634-->Arg (germline) mutations have a higher risk of developing parathyroid disease than those with other mutations at codon 634.

Adenoma↗

PubMed1995

Topographic abnormalities of proinsulin to insulin conversion in functioning human insulinomas. Comparison of immunoelectron microscopic and clinical data.

It has been proposed that the major defect in human insulinomas is a decreased hormone storage capacity resulting in uncontrolled release of proinsulin and insulin. By immunoelectron microscopy with monoclonal antibodies we studied the subcellular distribution of proinsulin and insulin in benign and malignant functioning insulinomas of different histology and compared the findings with various clinical and pathohistological parameters. We found that, in contrast to normal B cells, the proinsulin to insulin conversion in insulinomas occurs already in the trans Golgi apparatus but remains incomplete, resulting in the formation of secretory granules containing both proinsulin and insulin. Thus, in functioning insulinomas, sorting into secretory granules is not a prerequisite for hormone conversion. Furthermore, proinsulin and insulin storage and most probably subsequent secretion occurs through the secretory granules via the regulated pathway. A substantial variability for both proinsulin and insulin immunolabeling in secretory granules was found not only in individual tumor cells but also among the insulinomas studied. This observed variability may account for the lack of correlation between pathohistological, immunohistochemical, and clinical parameters in functioning insulinomas.

Adult↗

PubMed1995

[Dose-volume histograms for optimization of radiotherapy planning based on the example of esophageal carcinoma].

PURPOSE: The tissue tolerance of a small radiation dose to a large tissue volume applied in small fractions is expected to be different from the tolerance of a high dose to a small volume given in large fractions. Corresponding criteria for judgment have to be worked out. METHODS: Using the example of oesophagus carcinoma, dose-volume histograms for diverse treatment techniques are calculated and judged by means of multiplanar isodose representations. RESULTS: The selected treatment plans are ranked with the aid of the dose-volume histograms. We distinguish the tissue inside and outside of the target volume. CONCLUSIONS: The description of the spatial dose distribution in dependence of the different volumes and the respective fractions of the tumor dose therein with the help of dose-volume histograms brings about a correlation between the physical parameters and the biological effects. In addition one has to bear in mind the consequences of measures that influence the reaction and the side-effects of radiotherapy (e.g. chemotherapy), i.e. the recuperation of the tissues that were irradiated intentionally or inevitably. Taking all that into account it is evident that the dose-volume histograms are a powerful tool for assessing the quality of treatment plans.

Esophageal Neoplasms↗

PubMed1995

Overlapping expression of immunohistochemical markers and synaptophysin mRNA in pheochromocytomas and adrenocortical carcinomas. Implications for the differential diagnosis of adrenal gland tumors.

BACKGROUND: The differential diagnosis of cortical versus medullary tumors of the adrenal gland may be a problem in diagnostic pathology. Conflicting results have been reported about the distribution of various immunohistochemical markers in the normal as well as neoplastic adrenal cortex and medulla. EXPERIMENTAL DESIGN: Archival, formaldehyde-fixed, and paraffin-embedded material comprising 27 adrenocortical carcinomas (ACC, meeting Weiss' histologic criteria), 28 pheochromocytomas (PCC), and adjacent nontumorous tissue (13 glands) were analyzed by immunogold-silver staining for the expression of polysialic acid (poly Sia), cytokeratins (CK), synaptophysin (SYN), chromogranin A (CrgA), somatostatin (SOM), calcitonin (CT), and the "adrenocortical marker" D11. Further, SYN mRNA expression was studied by nonradioactive in situ hybridization using digoxigenin-labeled oligonucleotide probes. RESULTS: In the normal adrenal gland, poly Sia was exclusively detected in the medulla and in cortical nerves. In ACCs, SYN immunoreactivity was present in 23 of 27 tumors (85%), D11 was present in 22 of 27 (81%), poly Sia was present focally in 8 of 27 (29%), and CK was present in 7 of 27 (25%). Synthesis of SYN in ACCS was demonstrated by mRNA in situ hybridization. Immunoreactivity for CrgA, SOM, or CT was not detectable. No difference of the marker profiles was seen in the nine clinically hormone-producing (three androgen, five corticosteroid, one mineralocorticoid) ACCs compared with the clinically silent tumors. In PCCs, all 28 tumors were immunoreactive for poly Sia and SYN; CrgA was detectable in 26 of 28 (93%), CT was detectable in 6 of 28 (21%), and SOM was detectable in 2 of 28 (7%) tumors. Staining for D11 or CK was undetectable. By immunohistochemistry, no distinction was possible between the 4 clinically malignant, the 6 multiple endocrine neoplasia type 2A-associated, and the 18 sporadic benign PCCs. CONCLUSIONS: Poly Sia of the neural cell adhesion molecule is consistently detected in normal adrenal medullary cells as well as in PCCs, and is occasionally focally expressed in ACCs. CrgA, CK, and D11 are reliable markers to immunohistochemically distinguish ACC from PCC. Immunoreactivity for SYN and detection of its mRNA in the majority of ACCs indicates the existence of tumor cells sharing both cortical and medullary features. Such focal neuroendocrine differentiation in ACCs can lead to confusion with PCCs.

Adrenal Cortex Neoplasms↗

PubMed1995

[Expression of CD44 isoforms in normal human liver and also in regenerative and neoplastic liver changes].

CD44 is a transmembrane glycoprotein of which a large number of isoforms exist. There is evidence, mostly from experimental systems, that isoforms of CD44 generated by alternative splicing of ten variant exons are involved in tumor invasion and metastasis formation. We have evaluated the expression of CD44 standard (CD44s) and variant exons (CD44v) encoded gene products in formalin-fixed and paraffin-embedded human liver specimens, using an immunohistochemical protocol with microwave-based antigen-retrieval and signal amplification. Tissue sections from normal, regenerative and neoplastic liver were studied. Our results indicate that: 1. in normal liver, both, hepatocytes and bile duct epithelia lacked detectable CD44s and CD44v containing isoforms; 2. most cirrhotic liver specimens were unreactive. Some regenerative nodules showed a focal weak positivity for CD44v5 and v9. Most proliferating bile ductules were weakly stained for CD44v9 and some of them also for v5 and v6; 3. most hepatocellular carcinomas displayed a heterogeneous staining of varying intensity for CD44v5, v6, v9 and CD44s. In a few tumors a weak staining for CD44v3 and v4 was also present. Furthermore, there was a tendency to an increased staining intensity of CD44 isoforms with decreasing differentiation; 4. cholangiocarcinomas showed a high expression of CD44s, v3, v5, v6 and v9 containing isoforms. We conclude that neoplastic transformation of hepatocytes and bile duct epithelia is associated with qualitative and quantitative changes in the expression of some CD44 variant exons encoded products. The clinical implications of these findings remain to be determined in a large series of patients.

Adenoma↗

PubMed1995

Expression of murine VCAM-1 in vitro and in different models of inflammation in vivo: correlation with immigration of monocytes.

VCAM-1 (vascular cell adhesion molecule-1) is a cytokine-inducible adhesion molecule which is known to mediate adhesion of mononuclear cells to endothelial cells in vitro via binding to the integrin VLA-4 (very late antigen-4). To further elucidate the role and regulation of VCAM-1 in vitro, we compared in vitro and in vivo expression of VCAM-1 in response to cytokines and investigated immunohistochemically the expression of VCAM-1 in three murine models of experimental inflammation. These models differed with regard to the pathogenetic mechanism, and the subsesquent infiltrate: allergic contact dermatitis (ACD) to DNFB as a T cell-controlled, DTH type of inflammation, cutaneous infection with Leishmania major as a chronic granulomatous inflammation and the cauterized cornea as a model for acute inflammation. VCAM-1 was found to be markedly enhanced on vascular endothelia in all types of inflammation and after subcutaneous administration of LPS and TNF-alpha. Administration of IL-4, however, failed to induce VCAM-1 both in vivo and in vitro. The increased VCAM-1 expression in the inflammatory models correlated with the appearance of infiltrating monocytes/macrophages. A concomitant influx of CD4-positive/CD8-positive lymphocytes was only observed in ACD and Leishmaniasis.

Animals↗

PubMed1994

Differential expression of cell surface sialoglycoconjugates on wild-type and cultured Ehrlich tumor cells as revealed by quantitative lectin-gold ultrastructural cytochemistry.

Three variants of the classical Ehrlich ascites tumor (EAT) cell have been studied by quantitative, sialic acid-specific, lectin-gold ultrastructural cytochemistry. Electron microscopic examination revealed pronounced differences in the surface morphology of the three cell variants. The wild-type Ehrlich cells (EAT-wt), grown in the peritoneal cavity of mice, exhibited a smooth surface profile. A variant form selected for growth as monolayer on basement membrane (EAT-c) showed a complex surface profile with numerous microvilli. The third variant (EAT-c/m), the cultured cells reinoculated into mice and passaged 20-25 times as ascites, presented a smooth surface profile similar to the EAT-wt cells. Quantitative single as well as double lectin-gold labeling revealed significant differences in the nature of cell surface sialoglycoproteins. The most significant finding was the presence of cell surface Neu5Ac alpha 2-6Gal residues as detected with the Sambucus nigra lectin on EAT-c and EAT-c/m cells, whereas EAT-wt cells contained little or none of such carbohydrate sequences. On the contrary, labeling by Maackia amurensis lectin, which recognizes the Neu5Ac alpha 2-3Gal beta 1-4GlcNAc sequence, was intense on all three Ehrlich cell variants; it was 20-60 times greater than alpha-2,6-linked sialic acid-containing glycoconjugates. Specific cell surface lectin binding combined with morphologic study appears to have identified a small subpopulation of cells within the ascites tumor that are capable of attaching to and growing on a basement membrane.

Animals↗

PubMed1994

[The apomorphine test in the differential diagnosis of Parkinsonism. Initial experience].

BACKGROUND: The reactivity of postsynaptic dopamine receptors in the striatum is preserved in Parkinson's disease (PD) but not in parkinsonian syndromes of various origin (PS). Hence, the effect of dopaminergic stimulation can serve as one of the diagnostic criteria allowing to distinguish between PD and PS. The present study aimed to ascertain the clinical utility of Apomorphine (APO), a powerful short acting direct D1 and D2 receptors agonist drug, in the differential diagnosis of PD and PS. METHODS AND RESULTS: We studied 39 patients presenting parkinsonian signs. Based on clinical examination, 23 subjects (7 f, 16 m, mean age (SD) 59.2 (7.8) years were diagnosed as having probable PD, and 16 patients (5 f, 11 m, mean age 72 (7.6) yrs, p < 0.001) as having probable PS. In the PD group, mean Hoehn and Yahr degree of severity was 2.7 (1.1), mean duration of the disease 9.5 (6.2) yrs, mean duration of L-DOPA treatment (20 patients) 6.7 (5.5) yrs. In the PS group, the respective values of Hoehn and Yahr were 3.3 (0.9), mean duration of the disease 6.2 (4.1) yrs and mean duration of L-DOPA treatment (10 patients) 1.6 (1.1) yrs. After an overnight withdrawal of all other dopaminergic medication, a single subcutaneous dose of Apomorphine hydrochloride solution corresponding to 0.05 mg per kg of weight was administered. Domperidone was given 60 mg daily prior to the testing to avoid undesirable peripheral effects of APO. 20 minutes after APO administration, we noted a marked clinical improvement i.e. at least 30% decrease of pre-treatment motor score values on Columbina University Rating Scale (CURS) in 19 of 23 PD and in one of 16 PS patients. In the PD group, the difference between mean CURS values, 30.7 (19.5) before and 14.7 (10.3) after APO was highly significant (p < 0.001). In the PS group, only a slight posttreatment CURS decrease was found, 39.8 (17.5) before and 37.8 (17.5) after APO (p < 0.05). CONCLUSIONS: In individual patients, these results mostly confirm the presumed diagnosis of PD or PS. Even in the most serious cases from the PD group, the testing showed that the function of dopamine receptors in the striatum was still preserved. Thus, the Apomorphine test appears to be a helpful tool for differential diagnosis of PD and PS.

Aged↗

PubMed1994

Cellular site of synthesis and dynamics of cell surface re-expression of polysialic acid of the neural cell adhesion molecule.

Homopolymers of alpha-2,8-ketosidically linked sialic acid (polysialic acid) represent a posttranslational modification which, in mammals, appears to be unique for the neural cell adhesion molecule and the alpha subunit of sodium channels in brain. Under steady-state conditions, polysialic acid is detectable in the plasma membrane of different cell types but not in the cytoplasm. We have studied the site of synthesis and the cell surface re-expression of polysialic acid in a clonal subline of small cell lung carcinoma using the monoclonal antibody 735 and bacteriophage endosialidase, both specific reagents for polysialic acid. After enzymic removal, cell surface polysialic acid re-expression reached control levels only after 5 days. When Golgi to plasma membrane transport of endosialidase-treated cells was blocked by culture at 20 degrees C or in the presence of monensin at 37 degrees C, de-novo-synthesized polysialic acid became detectable in the Golgi apparatus. Our data show that synthesis of polysialic acid of the neural cell adhesion molecule with a degree of polymerization of at least nine occurs intracellular in the Golgi apparatus of a human small cell lung carcinoma cell line.

Animals↗

PubMed1994

A synthetic tris-sulfotyrosyl dodecapeptide analogue of the insulin receptor 1146-kinase domain inhibits tyrosine dephosphorylation of the insulin receptor in situ.

A synthetic tris-sulfotyrosyl dodecapeptide (TRDIY(S)ETDY(S)Y(S)RK-amide), whose primary sequence is identical to the 1142-1153 sequence of the insulin proreceptor, inhibited insulin receptor dephosphorylation in solubilized membranes, and digitonin-permeabilized cells derived from Chinese hamster ovary (CHO) cells expressing high levels of human insulin receptors (CHO/HIRc). It also inhibited the dephosphorylation of a synthetic tyrosine phosphorylated substrate by recombinant PTP-1B, a protein tyrosine phosphatase (PTPase), indicating that it acted via interaction with PTPase(s). A N-stearyl derivative of the peptide caused an approximately 4.5-fold increase in insulin-stimulated receptor autophosphorylaction in intact CHO/HIRc cells. The peptide displayed specificity toward tyrosine-class phosphatases only, as it had no effect on the activities of the serine/threonine phosphatases PP-1 and PP-2A, or alkaline phosphatase. The tyrosine sulfate ester bonds of the peptide were stable when incubated with PTP-1B (1 h, 30 degrees C). These data suggest that the sulfotyrosyl peptide functions as a nonhydrolyzable phosphotyrosyl peptide analogue capable of direct interaction with PTPase catalytic domain.

Alkaline Phosphatase↗