scholarly journals Effect of Rectal Levodopa Administration: A Case Report

2015 ◽  
Vol 7 (3) ◽  
pp. 209-212 ◽  
Author(s):  
Jolanda M.J. Vogelzang ◽  
Marianne Luinstra ◽  
A. Wijnand F. Rutgers
Keyword(s):  
Treatment Options ◽  
Oral Intake ◽  
Rectal Administration ◽  
Oral Medication ◽  
Acid Transport ◽  
Rectal Absorption ◽  
Amino Acid Transport System ◽  
Specific Amino Acid ◽  
Once Daily ◽  
Full Control

Objective: The aim of this report is to discuss whether or not rectal levodopa administration is useful in some situations. Background: In situations where oral intake of levodopa formulations is not possible, the treatment options of Parkinson's disease patients are limited. The literature describes no or low rectal absorption of levodopa. Case Description: A patient with an ileus was unable to take oral medication. After consulting the neurologist and pharmacist, the surgeon decided to describe a rectal formulation of levodopa/carbidopa (100/25 mg) once daily. On day 3 of the therapy, 1 h after administration of the rectal formulation of levodopa/carbidopa, a blood sample was drawn. The patient was unable to take his other Parkinson medication; therefore the dose of the rectal levodopa/carbidopa was increased to 5 times a day. Results: Full control of the symptoms was not achieved, but alleviation of the most severe tremor and rigidity was seen, which was confirmed by the neurologist, nurses and patient. The levodopa concentration detected was 17 nmol/l. Compared to levodopa concentrations described in the literature (1,400-12,000 nmol/l), the concentration is very low. There are some possible explanations for the low concentration detected. The presence of a specific amino acid transport system in the rectum is not known, which could lead to no or reduced absorption. The poor rectal absorption of carbidopa leads to a higher conversion of levodopa to dopamine peripherally. Conclusions: In situations where patients are unable to take oral medication, rectal administration of levodopa/carbidopa is worth considering.

scholarly journals Substrate specificity of amino acid transport in sheep erythrocytes

1977 ◽  
Vol 162 (1) ◽  
pp. 33-38 ◽  
Author(s):  
J D Young ◽  
J C Ellory
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Transport ◽  
Acid Transport ◽  
Inhibitory Potency ◽  
Amino Acid Transport System ◽  
Specific Amino Acid ◽  
Sheep Erythrocytes ◽  
Alpha Beta ◽  
Dibasic Amino Acids

The specificity of amino acid transport in normal (high-glutathione) sheep erythrocytes was investigated by studying the interaction of various neutral and dibasic amino acids in both competition and exchange experiments. Apparent Ki values were obtained for amino acids as inhibitors of L-alanine influx. Amino acids previously found to be transported by high-glutathione cells at fast rates (L-cysteine, L-alpha-amino-n-butyrate) were the most effective inhibitors. D-Alanine and D-alpha-amino-n-butyrate were without effect. Of the remaining amino acids studied, only L-norvaline, L-valine, L-norleucine, L-serine and L-2,4-diamino-n-butyrate significantly inhibited L-alanine uptake. L-Alanine efflux from pre-loaded cells was markedly stimulated by extracellular L-alanine. Those amino acids that inhibited L-alanine influx also stimulated L-alanine efflux. In addition, D-alanine, D-alpha-amino-n-biutyrate, L-threonine, L-asparagine, L-alpha, beta-diaminoproprionate, L-ornithine, L-lysine and S-2-aminoethyl-L-cysteine also significantly stimulated L-alanine efflux. L-Lysine uptake was inhibited by L-alanine but not by D-alanine, and the inhibitory potency of L-alanine was not influenced by the replacement of Na+ in the incubation medium with choline. L-Lysine efflux from pre-loaded cells was stimulated by L-alanine but not by D-alanine. It is concluded that these cells possess a highly selective stero-specific amino acid-transport system. Although the optimum substrates are small neutral amino acids, this system also has a significant affinity for dibasic amino acids.

The vacuolar amino acid transport system is a novel, direct target of GATA transcription factors

2021 ◽  
Vol 85 (3) ◽  
pp. 587-599
Author(s):  
Akane Sato ◽  
Takumi Kimura ◽  
Kana Hondo ◽  
Miyuki Kawano-Kawada ◽  
Takayuki Sekito
Keyword(s):  
Transcription Factors ◽  
Amino Acid ◽  
Amino Acid Transport ◽  
Amino Acid Transporters ◽  
Acid Transport ◽  
Amino Acid Transport System ◽  
Gata Transcription Factor ◽  
Gata Transcription Factors ◽  
Acid Status ◽  
Direct Target

ABSTRACT In Saccharomyces cerevisiae, Avt4 exports neutral and basic amino acids from vacuoles. Previous studies have suggested that the GATA transcription factors, Gln3 and Gat1, which are key regulators that adapt cells in response to changes in amino acid status, are involved in the AVT4 transcription. Here, we show that mutations in the putative GATA-binding sites of the AVT4 promoter reduced AVT4 expression. Consistently, a chromatin immunoprecipitation (ChIP) assay revealed that Gat1-Myc13 binds to the AVT4 promoter. Previous microarray results were confirmed that gln3∆gat1∆ cells showed a decrease in expression of AVT1 and AVT7, which also encode vacuolar amino acid transporters. Additionally, ChIP analysis revealed that the AVT6 encoding vacuolar acidic amino acid exporter represents a new direct target of the GATA transcription factor. The broad effect of the GATA transcription factors on the expression of AVT transporters suggests that vacuolar amino acid transport is integrated into cellular amino acid homeostasis.

Osmotic Regulation of ATA2 mRNA Expression and Amino Acid Transport System A Activity

2001 ◽  
Vol 283 (1) ◽  
pp. 174-178 ◽  
Author(s):  
Roberta R. Alfieri ◽  
Pier-Giorgio Petronini ◽  
Mara A. Bonelli ◽  
Alessandro E. Caccamo ◽  
Andrea Cavazzoni ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mrna Expression ◽  
Transport System ◽  
Amino Acid Transport ◽  
Osmotic Regulation ◽  
Acid Transport ◽  
Amino Acid Transport System ◽  
System A

scholarly journals 662 MICROVASCULAR MYOCUTANEOUS AND CUTANEOUS FREE FLAP RECONSTRUCTION FOR PATIENTS WITH TERMINAL ESOPHAGOSTOMY AFTER COMPLICATED ONCOLOGICAL ESOPHAGUS RESECTION

2021 ◽  
Vol 34 (Supplement_1) ◽  
Author(s):  
Lukas Pölsler ◽  
Jaroslav Presl ◽  
Christian Brandtner ◽  
Alexander Gaggl ◽  
Jörg Hutter ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Free Flap ◽  
Treatment Options ◽  
Graft Function ◽  
Oral Intake ◽  
Artificial Nutrition ◽  
Severe Problem ◽  
Promising Alternative ◽  
Number Of Patients

Abstract   Persisting anastomotic leak after oncological esophagectomy is a severe problem associated with high mortality and morbidity. Unfortunately, treatment options with promising results are scarce especially when conventional operative and endoscopic methods have failed. Due to limitation of oral intake and need for artificial nutrition quality of life is reduced. Microvascular myocutaneous and cutaneous free flap (MFF) reconstruction could be a promising alternative. Methods This retrospective cohort study presents seven patients treated between March 2017 and November 2020 at our surgical department, with terminal esophagostomy after complicated oncological esophagus resection without further feasible treatment options. All Patients received anastomotic MFF reconstruction. We have examined postoperative outcomes, complications according to Clavien-Dindo-Classification and patient contentment with a questionnaire. Additionally, we described important procedure related facts. Results The included seven male patients had median age of 65.15 years (range: 48–75). MFF function was adequate in six out of seven patients, graft rejection appeared in one patient. Five patients initially had good results, surgical revision was performed in one patient to ensure graft function. Postoperative complications appeared in 6/7 patients (Table 1). Mean duration of inpatient care was 63 days (Range: 24–156). At time of evaluation, one patient has died cancer related. No more additional nutrition was needed in 3/6 patients with adequate graft function. The majority of patients reported an improved quality of life compared to preoperatively. Conclusion MFF free flap can be a safe and feasible treatment option for patients with terminal esophagostomy after complicated oncological esophagus resection without further treatment options or in patients with complicated postoperative course with complex combined defects. The renewed ability of oral food intake results in a significant improvement of quality of life for the patients. No procedure related mortality was observed. Number of patients with regained ability of oral intake is encouraging.

Expression and regulation of 4F2hc and hLAT1 in human trophoblasts

2002 ◽  
Vol 282 (1) ◽  
pp. C196-C204 ◽  
Author(s):  
Yoko Okamoto ◽  
Masahiro Sakata ◽  
Kazuhiro Ogura ◽  
Toshiya Yamamoto ◽  
Masaaki Yamaguchi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Line ◽  
Transport System ◽  
Human Placenta ◽  
Amino Acid Transport ◽  
Calcium Ionophore ◽  
Acid Transport ◽  
Amino Acid Transport System ◽  
System L ◽  
Choriocarcinoma Cell Line

The neutral amino acid transport system L is a sodium-independent transport system in human placenta and choriocarcinoma cells. Recently, it was found that the heterodimer composed of hLAT1 (a light-chain protein) and 4F2 heavy chain (4F2hc), a type II transmembrane glycoprotein, is responsible for system L amino acid transport. We found that the mRNAs of 4F2hc and hLAT1 were expressed in the human placenta and a human choriocarcinoma cell line. The levels of the 4F2hc and hLAT1 proteins in the human placenta increased at full term compared with those at midtrimester. Immunohistochemical data showed that these proteins were localized mainly in the placental apical membrane. Data from leucine uptake experiments, Northern blot analysis, and immunoblot analysis showed that this transport system was partially regulated by protein kinase C and calcium ionophore in the human choriocarcinoma cell line. Our results suggest that the heterodimer of 4F2hc and hLAT1 may play an important role in placental amino acid transport system L.

Effect of structural analogues on intestinal accumulation of glycine

1962 ◽  
Vol 203 (4) ◽  
pp. 634-636 ◽  
Author(s):  
Richard P. Spencer ◽  
Janet Weinstein ◽  
Arthur Sussman ◽  
Ted M. Bow ◽  
Mary Anne Markulis
Keyword(s):  
Glutaric Acid ◽  
Succinic Dehydrogenase ◽  
Acid Transport ◽  
Depressant Effect ◽  
Amino Acid Transport System ◽  
Glycine Uptake ◽  
Hydrocinnamic Acid ◽  
Structural Analogues ◽  
Intestinal Segments

Glycine uptake (1 x 10–3 m) by hamster intestinal segments in vitro was studied after 20 min of incubation both in the absence and presence of various analogues (5 x 10–3 m). A variety of chemical relatives of glycine with modifications of the —COOH, —NH2, or α-hydrogen groups or with double modifications (such as ethanol) were without effect on glycine accumulation. Thus under these conditions glycine could not be displaced by its analogues. Three compounds, however, all α-amino acids, were effective in depressing glycine uptake (allylglycine, α-phenylglycine, l-alanine). Data are presented showing that two of these inhibitors are themselves transported and hence likely competed with the amino acid transport system. α-Aminoisobutyric acid and N-methylglycine, both known to be transported by the gut, did not interfere with glycine accumulation. In addition to oxalic acid, other succinic dehydrogenase inhibitors (hydrocinnamic acid, glutaric acid, malonic acid at 5 x 10–3 m) were without major depressant effect on glycine accumulation by this system.

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