scholarly journals Lactitol, a new hydrogenated lactose derivative: intestinal absorption and laxative threshold in normal human subjects

1987 ◽  
Vol 57 (2) ◽  
pp. 195-199 ◽  
Author(s):  
Dharmaraj H. Patil ◽  
George K. Grimble ◽  
David B. A. Silk
Keyword(s):  
Side Effects ◽  
Maximum Dose ◽  
Human Subjects ◽  
Normal Subjects ◽  
Perfusion Technique ◽  
Double Blind ◽  
Gastrointestinal Side Effects ◽  
Normal Human ◽  
Jejunal Perfusion

1. In the first part of the study, the absorption of lactitol, a new disaccharide analogue of lactose, was studied using an in vivo jejunal perfusion technique in man. Intestinal uptake of lactitol from isotonic solutions containing 10, 30, 60, and 100 mmol lactitol/l was insignificant.2. In the second part of the study the laxative threshold of lactitol was determined and compared with that of sorbitol in a double-blind, randomized, cross-over study on twenty-one normal subjects. Laxative threshold was considered to be either the maximum dose tolerated without unacceptable diarrhoea or gastrointestinal side effects, or when the maximum dose in the study was reached. Increasing amounts of lactitol, sorbitol or placebo were administered in two divided doses each day until subjects developed diarrhoea or severe gastrointestinal side effects. The laxative threshold of lactitol (74 (SE 5) g/d) was similar to that of sorbitol (71 (SE 5) g/d).3. These findings indicate that lactitol is not absorbed by the human small intestine. Although diarrhoea or other gastrointestinal side effects occurred as the dose was increased, 40 g lactitol/d was well tolerated.

Platelet catecholamines and platelet function in normal human subjects

1987 ◽  
Vol 73 (1) ◽  
pp. 99-103 ◽  
Author(s):  
A. P. Wilson ◽  
C. C. T. Smith ◽  
B. N. C. Prichard ◽  
D. J. Betteridge
Keyword(s):  
Platelet Function ◽  
High Performance ◽  
Human Subjects ◽  
Normal Subjects ◽  
Noradrenaline Content ◽  
Collagen Concentration ◽  
Normal Human ◽  
Wall Interaction ◽  
Local Release

1. We have used high-performance liquid chromatography with electrochemical detection to measure plasma and platelet catecholamines in 24 normal subjects. 2. In the same subjects platelet function was assessed by measuring platelet aggregation in response to adenosine 5′-pyrophosphate, thrombin, adrenaline and collagen. Platelet sensitivity to prostacyclin was also examined. 3. Platelet noradrenaline showed a positive correlation with extent of aggregation induced by ‘low-dose’ collagen (1 μg/ml). No correlation was seen at the higher collagen concentration. 4. Platelet noradrenaline content also correlated with sensitivity of platelets to prostacyclin. High platelet noradrenaline concentrations appeared to result in decreased sensitivity to prostacyclin. 5. No other correlations were observed. 6. These data suggest that platelet noradrenaline rather than plasma levels may be involved in modifying platelet function in vivo. Local release of platelet catecholamines may affect the platelet/vessel wall interaction, the primary physiological step in platelet activation.

Intestinal Absorption of Cystine and Cysteine in Normal Human Subjects and Patients with Cystinuria

1974 ◽  
Vol 47 (4) ◽  
pp. 393-397 ◽  
Author(s):  
D. B. A. Silk ◽  
D. Perrett ◽  
A. D. Stephens ◽  
M. L. Clark ◽  
E. F. Scowen
Keyword(s):  
Intestinal Absorption ◽  
Human Subjects ◽  
Transport Processes ◽  
Intestinal Perfusion ◽  
Perfusion Technique ◽  
Normal Human

1. An intestinal perfusion technique has been used to study absorption in vivo of l-cystine and l-cysteine in six normal human subjects and three patients with homozygous cystinuria. 2. No significant absorption of l-cystine was detected during perfusion of the cystinuric patients, whereas l-cysteine absorption was normal. These results imply that l-cystine and l-cysteine are normally absorbed by different transport processes. 3. No significant reduction of l-cystine to l-cysteine occurred in the gut lumen during the perfusion experiments. No more oxidation of l-cysteine to l-cystine occurred in the gut lumen during the perfusion experiments than in the test solutions which were simultaneously incubated in vitro.

Nonadrenergic bronchodilator mechanisms in normal human subjects in vivo

1988 ◽  
Vol 64 (5) ◽  
pp. 1817-1822 ◽  
Author(s):  
J. W. Lammers ◽  
P. Minette ◽  
M. T. McCusker ◽  
K. F. Chung ◽  
P. J. Barnes
Keyword(s):  
Nervous System ◽  
Local Anesthesia ◽  
Ipratropium Bromide ◽  
Human Subjects ◽  
Normal Subjects ◽  
Respiratory Resistance ◽  
Leukotriene D4 ◽  
Normal Human ◽  
Oral Propranolol

In seven normal subjects we investigated whether a nonadrenergic bronchodilator nervous system is demonstrable in humans in vivo. After inhalation of leukotriene D4 (LTD4), respiratory resistance (Rrs) increased by 115 +/- 11% (SE). Subsequent inhalation of 2 nmol of capsaicin induced coughing and a fall in Rrs of 22.1 +/- 2% (P less than 0.01). However, inhalation of the diluent of capsaicin, 10% saline-ethanol, decreased Rrs similarly. These bronchodilator responses were not altered by inhaled ipratropium bromide (120 micrograms) and oral propranolol (80 mg). After ipratropium and propranolol, voluntary coughing alone decreased Rrs by 25 +/- 3% (P less than 0.05). We next investigated whether these bronchodilator responses could be blocked by anesthesia of the airways with inhaled lidocaine. After inhalation of lidocaine and LTD4, capsaicin aerosol induced coughing and a transient increase in Rrs of 18 +/- 6% (P less than 0.05) but no bronchodilation. Inhalation of saline-ethanol (n = 4) and a deep inhalation (n = 6) decreased Rrs by 18 +/- 4% (P less than 0.05) and 34 +/- 3% (P less than 0.001), respectively. We conclude that in normal subjects a nonadrenergic, noncholinergic bronchodilator mechanism exists, which can be activated by inhalation of capsaicin and inhibited by local anesthesia.

Pomegranate, its Components and Modern Deliverable Formulations as Potential Botanicals in the Prevention and Treatment of Various Cancers

2021 ◽  
Vol 18 ◽  
Author(s):  
Laila Hussein ◽  
Mostafa Gouda ◽  
Harpal S. Buttar
Keyword(s):  
Side Effects ◽  
Biological Tissues ◽  
Pomegranate Juice ◽  
In Vivo Studies ◽  
Lifestyle Modifications ◽  
Cellular Mechanisms ◽  
Double Blind ◽  
Prevention And Treatment

Abstract: Cancer is a global multifactorial disease consisting of over 200 types of cancers. It is well recognized that primary prevention is an effective way to fight cancers by using natural polyphenolic anticancer foods, vegetables and fruits, avoiding exposure to carcinogenic environment, smoking cessation, and through lifestyle modifications. The present review provides up to date information on the effects and functions of pomegranate juice and its bioactive components on the most widespread six cancer types. Pomegranate contains important polyphenolic compounds such as ellagitannins and punicalagin, with strong antioxidant ability for scavenging free radicals and producing metal-chelates in the biological tissues. The in vitro and in vivo studies suggests that antioxidant and anti-inflammation properties of pomegranate constitute have major antimutagenic and antiproliferative activities for regulating gene expression, modulating cellular mechanisms, and limiting the ability of cancers to metastasize. A limited number of clinical studies have suggested that pomegranate ingredients have the potential for the prevention and treatment of cancer, especially colorectal and prostate cancer. In cancer therapy, it remains a clinical dilemma to hit the right target without inducing side effects. The costly anticancer chemotherapies are often associated with drug resistance and serious side effects in vital organs, and noncancerous neighboring cells. It appears that the pomegranate based phytotherapies would be affordable and cost-effective for next generation non-pharmacologic anticancer remedies with lesser side effects. However, well-designed, randomized, double-blind, and multi-center studies are needed to establish the long-term safety, efficacy and dose schedules for orally deliverable pomegranate formulations.

Bronchoprotective and bronchodilatory effects of deep inspiration in rabbits subjected to bronchial challenge

2001 ◽  
Vol 91 (6) ◽  
pp. 2511-2516 ◽  
Author(s):  
S. J. Gunst ◽  
X. Shen ◽  
R. Ramchandani ◽  
R. S. Tepper
Keyword(s):  
Human Subjects ◽  
Inhibitory Effect ◽  
Airway Responsiveness ◽  
Deep Inspiration ◽  
Contractile Apparatus ◽  
Airway Reactivity ◽  
Airway Response ◽  
Normal Human ◽  
Airway Responses

The effect of deep inspiration (DI) on airway responsiveness differs in asthmatic and normal human subjects. The mechanism for the effects of DI on airway responsiveness in vivo has not been identified. To elucidate potential mechanisms, we compared the effects of DI imposed before or during induced bronchoconstriction on the airway response to methacholine (MCh) in rabbits. The changes in airway resistance in response to intravenous MCh were continuously monitored. DI depressed the maximum response to MCh when imposed before or during the MCh challenge; however, the inhibitory effect of DI was greater when imposed during bronchoconstriction. Because immature rabbits have greater airway reactivity than mature rabbits, we compared the effects of DI on their airway responses. No differences were observed. Our results suggest that the mechanisms by which DI inhibits airway responsiveness do not depend on prior activation of airway smooth muscle (ASM). These results are consistent with the possibility that reorganization of the contractile apparatus caused by stretch of ASM during DI contributes to depression of the airway response.

scholarly journals Noninvasive Measurements of Human Brain Temperature Using Volume-Localized Proton Magnetic Resonance Spectroscopy

1997 ◽  
Vol 17 (4) ◽  
pp. 363-369 ◽  
Author(s):  
Ron Corbett ◽  
Abbot Laptook ◽  
Paul Weatherall
Keyword(s):  
Magnetic Resonance ◽  
Frontal Lobe ◽  
Mr Spectroscopy ◽  
Brain Temperature ◽  
Human Subjects ◽  
Normal Subjects ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
Noninvasive Measurements

Elucidation of the role of cerebral hyperthermia as a secondary factor that worsens outcome after brain injury, and the therapeutic application of modest brain hypothermia would benefit from noninvasive measurements of absolute brain temperature. The present study was performed to evaluate the feasibility of using 1H magnetic resonance (MR) spectroscopy to measure absolute brain temperature in human subjects on a clinical imaging spectroscopy system operating at a field strength of 1.5 T. In vivo calibration results were obtained from swine brain during whole-body heating and cooling, with concurrent measurements of brain temperature via implanted probes. Plots of the frequency differences between the in vivo MR peaks of water and N-acetyl-aspartate and related compounds (NAX), or water and choline and other trimethylamines versus brain temperature were linear over the temperature range studied (28–40°C). These relationships were used to estimate brain temperature from 1H MR spectra obtained from 10 adult human volunteers from 4 cm3-volumes selected from the frontal lobe and thalamus. Oral and forehead temperatures were monitored concurrently with MR data collection to verify normothermia in all the subjects studied. Temperatures determined using N-acetyl-aspartate or choline as the chemical shift reference did not differ significantly, and therefore results from these estimates were averaged. The brain temperature (mean ± SD) measured from the frontal lobe (37.2 = 0.6°C) and thalamus (37.7 ± 0.6°C) were significantly different from each other (paired t-test, p = 0.035). We conclude that 1H MR spectroscopy provides a viable noninvasive means of measuring regional brain temperatures in normal subjects and is a promising approach for measuring temperatures in brain-injured subjects.

Catechol O-Methyltransferase in Red Blood Cells of Schizophrenic, Depressed, and Normal Human Subjects

1976 ◽  
Vol 128 (2) ◽  
pp. 184-187 ◽  
Author(s):  
Helen L. White ◽  
Malcolm N. McLeod ◽  
Jonathan R. T. Davidson
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Human Subjects ◽  
Normal Subjects ◽  
Enzyme Preparations ◽  
Human Red Blood Cells ◽  
Schizophrenic Patients ◽  
Normal Human ◽  
The Mean ◽  
Isoelectric Ph

SummaryCatechol O-methyltransferase of lysed human red blood cells was assayed under optimal conditions, using saturating concentrations of the substrates, S-adenosyl-L-methionine and 3,4-dihydroxybenzoic acid. The mean enzyme activity found in 24 normal subjects was 29.2 nmol/hr/ml RBC. The mean activity in blood of 33 female unipolar depressives was not significantly different from normal. However, higher enzyme activities were observed in the blood of 11 schizophrenic patients (38.9 nmol/hr/ml RBC). Partially purified enzyme preparations from blood of normal and schizophrenic individuals were indistinguishable with respect to substrate specificities, isoelectric pH values, and ratios of the two O-methylated products. Therefore it is unlikely that any defect in O-methylation which may occur in schizophrenia can be attributed to a change in the intrinsic properties of erythrocyte catechol O-methyltransferase.

Lithium and erythrocyte membrane cation carrier studies in normal and manic depressive subjects

1977 ◽  
Vol 7 (2) ◽  
pp. 229-233 ◽  
Author(s):  
G. J. Naylor ◽  
A. Smith ◽  
L. J. Boardman ◽  
D. A. T. Dick ◽  
E. G. Dick ◽  
...  
Keyword(s):  
Erythrocyte Membrane ◽  
Human Subjects ◽  
Normal Subjects ◽  
Sodium Concentration ◽  
Manic Depressive Psychosis ◽  
Manic Depressive ◽  
Normal Human ◽  
Potassium Influx ◽  
Erythrocyte Sodium

synopsisChanges in the erythrocyte membrane cation carrier following lithium ingestion in normal human subjects were studied; ouabain sensitive potassium influx fell significantly during the lithium treated phase. Lithium was fed to rats and no change in erythrocyte Na-K ATPase was shown. These findings contrast with studies of lithium in manic depressive psychosis. The fluctuations in the erythrocyte membrane cation carrier were studied in 5 normal subjects over 12 weeks and the correlations between the parameters calculated. The erythrocyte sodium concentration correlated positively with the ouabain sensitive potassium influx. This too contrasts with findings in manic depressive psychosis.

Aminophylline and human diaphragm strength in vivo

1990 ◽  
Vol 68 (6) ◽  
pp. 2591-2596 ◽  
Author(s):  
R. D. Levy ◽  
S. Nava ◽  
L. Gibbons ◽  
F. Bellemare
Keyword(s):  
Motor Units ◽  
Normal Subjects ◽  
Acute Administration ◽  
Transdiaphragmatic Pressure ◽  
Gastric Pressure ◽  
Significant Difference ◽  
Before And After ◽  
Normal Human ◽  
Twitch Characteristics

The transdiaphragmatic pressure (Pdi) twitch response to single shocks from supramaximal bilateral phrenic nerve stimulation was studied before and after acute intravenous infusions of aminophylline [14.9 +/- 3.1 (SD) micrograms/ml] in nine normal subjects. Stimulation was performed with subjects in the sitting position against an occluded airway from end expiration. Baseline gastric pressure and abdominal and rib cage configuration were kept constant. There was no significant difference in peak twitch Pdi from the relaxed diaphragm between control (38.8 +/- 3.3 cmH2O) and aminophylline (40.2 +/- 5.2 cmH2O) experiments. Other twitch characteristics including contraction time, half-relaxation time, and maximum relaxation rate were also unchanged. The Pdi-twitch amplitude at different levels of voluntary Pdi was measured with the twitch occlusion technique, and this relationship was found to be similar under control conditions and after aminophylline. With this technique, maximum Pdi (Pdimax) was calculated as the Pdi at which stimulation would result in no Pdi twitch because all motor units are already maximally activated. No significant change was found in mean calculated Pdimax between control (146.9 +/- 27.0 cmH2O) and aminophylline (149.2 +/- 26.0 cmH2O) experiments. We conclude from this study that the acute administration of aminophylline at therapeutic concentrations does not significantly affect contractility or maximum strength of the normal human diaphragm in vivo.

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