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Results for “Potassium Ion Level”

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At least 73 records · Page 4Linked to original sources
PubMed1987

Clinical trial of gossypol as a male contraceptive drug. Part II. Hypokalemia study.

A randomized controlled study was designed to evaluate the merit of whether ingesting potassium salt or potassium (K) blocking agent while using gossypol contraceptive drug could alleviate the symptom of hypokalemia. Results indicate that K salt supplementation did not reverse the gossypol-related hypokalemia and that the blocking agent triamterene did not prevent loss of or enhance the retention of serum K.

Blood Pressure↗
PubMed1990

A comparison of rice-based oral rehydration solution and "early feeding" for the treatment of acute diarrhea in infants.

To compare the use of rice-based oral rehydration solution (R-ORS), with the introduction of food immediately after rehydration ("early feeding"), using standard glucose-based oral rehydration solution (G-ORS) in the management of acute diarrhea, we conducted a four-cell randomized, controlled trial among 200 hospitalized Egyptian infants between 3 and 18 months of age. During the rehydration phase (first 4 hours), three groups were given G-ORS and a fourth group was given R-ORS. During the subsequent maintenance phase, the control group was given a soy-based, lactose-free formula (G-ORS + SF), a second group (G-ORS + RF) was given a rice-based formula, and a third group (G-ORS + rice) was given boiled rice. The fourth group (R-ORS + SF) continued to receive R-ORS for the first 24 hours of the maintenance period, followed by a soy-based lactose-free formula. During the first and second 24 hours of the maintenance period, infants in the three treatment groups had a lower mean stool output in comparison with the control group (p = 0.006 and 0.03, respectively). The mean total stool output in the R-ORS + SF group was significantly lower than in the control group (p = 0.02). There were no statistically significant differences among the four groups in the mean duration of diarrhea. We conclude that (1) infants who were given R-ORS had reduced total stool output (by 35%) compared with the control group and (2) feeding of boiled rice or a rice-based formula immediately after rehydration therapy was as efficacious as treatment with R-ORS alone for 24 hours, followed by feeding with a soy-based, lactose-free formula.

Acute Disease↗
PubMed1995

Triplex formation at the rat neu gene utilizing imidazole and 2'-deoxy-6-thioguanosine base substitutions.

Triplex-forming oligodeoxyribonucleotides (TFOs) can be designed so as to form antiparallel triple helices with duplex DNA by means of GGC and TAT or AAT base triplets, and these have been shown to be useful as sequence-specific DNA binding agents. Using TFOs targeted to the promoter region of the rat neu oncogene, it is shown here that substitution of an imidazole-nucleoside chimera at a single site in a neu specific TFO results in an increase in TFO binding affinity and specificity. This effect is discussed in terms of the stabilizing effect of local imidazole-TA triplet formation. It is also found that site-selective substitution of 2'-deoxy-6-thioguanosine for guanosine (S6-dG) in the TFO results in an increase in triplex formation in the presence of physiological levels of potassium ion. The utility and positioning of S6-dG base substitutions is discussed in the context of an intramolecular tetrad model.

Animals↗
PubMedDate not supplied

Local prevention of oxidative stress in the intestinal epithelium of the rat by adhesive liposomes of superoxide dismutase and tempamine.

The purpose of the present study was to investigate whether the local prevention of luminal superoxide-mediated biological damage in the rat jejunal mucosa could be achieved by liposomal superoxide dismutase (SOD) and the SOD mimic tempamine (TMN). Cationic liposomes loaded with either SOD or TMN were perfused in the rat jejunum prior to the induction of oxidative insult. Reactive hydroxyl radicals were generated in situ in a closed circulating intestinal loop of the rat from the reaction between hypoxanthine and xanthine oxidase in the presence of chelated ferrous sulfate. Mucosal activity of lactate dehydrogenase and levels of potassium ions were used to quantify the tissue damage. Intracellular uptake and locality of SOD were examined in HT-29 cells. The intestinal uptake of SOD and TMN was further measured by using rat colon sacs. Entrapment in cationic liposomes was found to significantly enhance the antioxidant effect of SOD and TMN against the induced oxidative damage in the jejunal mucosa, compared with their free forms. The effect was found to be local and was caused by the increased mucosal adhesion of the liposomes. The cationic liposomes also triggered SOD uptake into the HT-29 cell line. It is concluded that the increased residence time of the cationic liposomes of SOD and TMN in the jejunal mucosa resulted in a local effect against oxidative injury. This local protection may be exploited for drug delivery purposes.

Adhesiveness↗
PubMed1998

Effects of oral contraceptives containing different progestogens on sodium-lithium countertransport in normal females.

In view of the lack of unanimity on the effect of long-term intake of combined oral contraceptives (OC) on external sodium-dependent lithium efflux, otherwise known as sodium-lithium countertransport (SLC), we undertook a double-blind study to investigate the possible interaction between SLC and OC in healthy women with regular menstrual cycles. In a group of 17 volunteers, aged 27.0 +/- 1.1 years (mean +/- s.e.m.) and weighing 61.4 +/- 2.0 kg, ingestion of 30 microg ethinyloestradiol + 150 microg desogestrel for 3 months caused an increase in SLC activity from a baseline value of 0.254 +/- 0.017 mmol/lcell x h to 0.274 +/- 0.017 mmol/lcell x h (P = 0.05). The activity of the transport system after 6 months treatment remained higher than at baseline (0.280 +/- 0.016 mmol/lcell x h, P < 0.025) but was comparable to that at 3 months. Blood pressure and weight remained unaltered during the study period. In a comparable group of 16 volunteers of age 26.1 +/- 1.3 years and weight 63.5 +/- 2.1 kg, control SLC activity (0.218 +/- 0.012 mmol/lcell x h) was comparable to that after 3 months (0.215 +/- 0.011 mmol/lcell x h) and 6 months (0.216 +/- 0.011 mmol/lcell x h) intake of 35 microg ethinyloestradiol + 2 mg cyproterone acetate. Body weight and blood pressure remained similarly unchanged. These results not only confirm that long-term intake of OC may cause increased SLC activity, but also suggest that the type of the progesterone in the medication used could be an important determinant of such interaction.

Adolescent↗
PubMed2000

Wernicke's syndrome after bariatric surgery.

Two young females with severe morbid obesity presented with Wernicke's syndrome after Roux-en-Y gastro-jejunum bypass had been performed. The first patient had recurrent vomiting and dyplopia two months post-surgery. Physical examination indicated bilateral ophthalmoparesia with conserved convergence and ataxia. The second patient had frequent vomiting episodes over the previous three months together with lower limb hypotonia, myoclonia and generalised tonicoclonic seizures on two occasions within one year of surgery. In both cases routine blood test, ion levels (sodium, potassium, calcium, phosphates), electroencephalogram and CT scan were normal. Thiamine therapy was instigated on the basis of clinical intuition and the first patient achieved complete remission within 24 hours while the second improved gradually in that two years later only mild lower limb hypotonia and a slight cognitive deficit remains. Erythrocyte transketolase activity determinations were abnormal on two separate occasions for this second patient. Vitamin B1 determinations were not available for the first patient. In conclusion, the restriction in energy intake and the persistent vomiting together with malabsorption induced by the surgical intervention could explain the vitamin deficiency causing Wernicke's encephalopathy. This indicates a need for close monitoring and systematic vitamin supplementation in those patients who undergo bariatric surgery.

Adult↗
PubMed1984

A population study on the relationship between blood pressure and the excretion of urinary cations.

The relationships between blood pressure and the 24-h excretion of three urinary cations (Ca2+, K+, and Na+) were investigated in a random sample of 528 adults (greater than or equal to 20 years) inhabitants of two Belgian towns. In these adults both systolic and diastolic blood pressures were strongly and independently correlated with age and body weight. Systolic pressure in women was significantly and positively related to pulse rate. After adjusting for age and body weight, systolic and diastolic pressures in men were significantly (p less than 0.001 and p less than 0.01, respectively) and negatively correlated with urinary potassium excretion. Diastolic pressure in men was weakly (p less than 0.05 after adjusting for body weight, age, and urinary potassium excretion) but positively correlated with calcium excretion. In a subsample of 162 premenopausal women, blood pressure was higher in current contraceptive pill users than in women not taking oral contraceptives. In 56 current pill users there was a positive association between systolic pressure and 24-h urinary sodium (p less than 0.01 after adjusting for age, body weight, and pulse rate). The present study indicates that urinary potassium is a consistent and negative predictor of both systolic and diastolic pressures in adult men, whose diastolic pressure is weakly and positively associated with urinary calcium. The positive association between systolic pressure and urinary sodium in current users of contraceptive pills may suggest that their blood pressure becomes responsive to their usual salt intake.

Adult↗
PubMed1993

Regulation of expression of mRNAs encoding the nerve growth factor receptors p75 and trkA in developing sensory neurons.

We have used a quantitative reverse transcription/polymerase chain reaction amplification technique to study the regulation of p75 mRNA and trkA mRNA expression in developing NGF-dependent trigeminal neurons. Before becoming NGF dependent, these neurons express low levels of p75 and trkA mRNAs in vivo. At this stage in vitro, the level of p75 mRNA is maintained and up-regulated by BDNF, whereas the level of trkA mRNA is sustained independently of neurotrophins and is down-regulated by BDNF. With the acquisition of NGF dependence, p75 and trkA mRNA levels increase markedly in vivo. At this stage in vitro, the level of p75 mRNA is up-regulated by NGF, but this response is lost at later stages. The level of trkA mRNA is sustained in neurons grown with NGF but is not up-regulated by concentrations of NGF above those required to support survival. At no stage during the early development of trigeminal neurons do depolarising levels of potassium ions affect the expression of either p75 mRNA or trkA mRNA. These findings suggest that the expression of p75 and trkA mRNAs are differentially regulated by BDNF and NGF at successive early stages of neuronal development.

Animals↗
PubMed1998

The effect of surgical treatment on secondary hyperaldosteronism and relative hyperinsulinemia in primary hyperparathyroidism.

OBJECTIVE: To evaluate the renin-aldosterone system and insulin secretion in hyperparathyroidism and their effects on blood pressure regulation. DESIGN: Studies were carried out on patients with primary hyperparathyroidism (PHPT) prior to and following removal of the parathyroid tumor. METHODS: Sixteen normotensive and euglycemic patients with PHPT were studied. The following parameters were measured: basal and stimulated plasma renin activity (PRA) and aldosterone (ALD) secretion: parathormone (PTH) and serum electrolytes. Insulin and glucose levels were measured during an oral glucose tolerance test. RESULTS: Systolic but not diastolic blood pressure showed a decrease following surgery, from 123.3+/-13.0/80+/-8.6 to 116.7+/-13.5/77.3+/-8.8 mmHg. The decrease in the systolic pressure was not clinically significant. After surgery, both the basal and stimulated PRA and ALD values decreased, and the preoperative pathological values returned to normal: PRA basal: 1.79 --> 0.70 ng/ml/h, P=0.0049; PRA stimulated: 7.76 --> 1.90 ng/ml/h, P=0.0031; ALD basal: 111.5 --> 73.0 pg/ml, P=0.0258; ALD stimulated: 392.5 --> 236.0 pg/ml, P=0.0157. The postoperative decrease in the PRA correlated with the changes in PTH levels (r=0.5442, P < 0.05, n=16) but did not correlate with the changes in serum calcium concentrations. Both the fasting and stimulated insulin levels decreased after surgery but remained within the normal range: insulin fasting: 10.2 --> 5.0 mIU/l, P=0.0218; insulin area under the curve: 5555 --> 3296 mIU/l*min, P=0.0218. There was no correlation between the changes in insulin levels and PTH or ion levels. Sodium, potassium and blood glucose levels remained unaffected by parathyroid surgery. CONCLUSIONS: In a population of normotensive hyperparathyroid patients an increased activity of the renin-aldosterone system related to PTH was found and surgery resulted in a small and insignificant decrease in blood pressure. This change was accompanied by a significant decrease in the activity of the renin-aldosterone system indicating the role of the renin-aldosterone system in the regulation of blood pressure in PHPT. Both fasting and stimulated insulin values decreased following removal of the parathyroid tumor, but with no individual correlation with PTH and calcium levels.

Adolescent↗
PubMed1995

The influence of thapsigargin on Na,K-ATPase activity in cultured nonpigmented ciliary epithelial cells.

Experiments were conducted to test the influence of thapsigargin on the NaK-ATPase activity of cultured cells (ODM2) derived from human nonpigmented ciliary epithelium. The rate of ouabain-sensitive ATP hydrolysis (Na,K-ATPase activity) was diminished in cells that had been pretreated with thapsigargin then permeabilized. Following 20 min exposure of intact cells to thapsigargin, the cells were permeabilized with digitonin and the rate of ouabain-sensitive ATP hydrolysis (Na,K-ATPase activity) was measured immediately in a calcium-free buffer. In permeabilized cells that had been pretreated with 1 microM thapsigargin for 20 min, the rate of ouabain-sensitive ATP hydrolysis (Na,K-ATPase activity) was reduced by 38%. Pretreatment with lesser concentrations of thapsigargin caused smaller changes of Na,K-ATPase activity. The decrease of Na,K-ATPase activity was the same whether or not calmodulin antagonists W7 or trifluoperazine were present during the thapsigargin pretreatment period. This inhibitory effect upon the Na,K-ATPase may serve to limit the extent of sodium pump activation that takes place in intact cells when thapsigargin causes sodium pump stimulation by a mechanism that appears to involve changes in cytoplasmic ion levels when potassium channels open.

Adenosine Triphosphate↗