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PubMed1992

Intestinal water absorption from select carbohydrate solutions in humans.

Eight men positioned a triple-lumen tube in the duodenojejunum. By use of segmental perfusion, 2, 4, 6, or 8% solutions of glucose (111-444 mM), sucrose (55-233 mM), a maltodextrin [17-67 mM, avg. chain length = 7 glucose units (7G)], or a corn syrup solid [40-160 mM, avg. chain length = 3 glucose units (3G)] were perfused at 15 ml/min for 70 min after a 30-min equilibration period. All solutions were made isotonic with NaCl, except 6 and 8% glucose solutions, which were hypertonic. An isotonic NaCl solution was perfused as control. Water absorption (range: 9-15 ml.h-1.cm-1) did not differ for the 2, 4, and 6% CHO solutions but was greater (P < 0.05) than absorption from control (3.0 +/- 2.2 ml.h-1.cm-1). The 8% glucose and 3G solutions reduced (P < 0.05) net water flux compared with their 2, 4, and 6% solutions, but 8% sucrose and 8% 7G solutions promoted water absorption equivalent to lower CHO concentrations. Water absorption was independent of [Na+] in the original solution. In the test segment, 1) Na+ flux correlated with net water flux (r = 0.72, P < 0.01), K+ (r = 0.78, P < 0.01), and [Na+] (r = 0.68, P < 0.001); 2) Na+ absorption occurred at luminal [Na+] as low as 50 mM; 3) glucose transport increased linearly over the luminal concentration range of 40-180 mM; and 4) net water flux was similar over a range of glucose-to-Na+ concentration ratios of 0.4:1 to 3.5:1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Safety of ozonated solution as an antiseptic of the ocular surface prior to ophthalmic surgery.

PURPOSE: To evaluate the safety of an ozonated solution as an antiseptic of the ocular surface prior to ophthalmic surgery. METHODS: In experiment 1, a primary culture of rabbit corneal epithelium was established. Then, 0, 4 and 10 ppm ozonated solution and 1.25% povidone-iodine, respectively, were applied to confluent cells on collagen-coated filter inserts (Millicell-CM) for 10 min followed by replacement with fresh medium. The transepithelial electrical resistance (TER), which is a good indicator of cell barrier function, was sequentially measured for 30 min. In experiment 2, adult pigmented rabbit eyes were washed with 20 ml of 4 ppm ozonated solution, 1.25% povidone-iodine solution or saline. Slitlamp examinations were performed before and after washing. RESULTS: In experiment 1, 4 ppm ozonated solution did not change the TER as compared with the control. 10 ppm ozonated solution and 1.25% povidone-iodine similarly reduced the TER values significantly as compared with those of the control and 4 ppm ozonated solution. In experiment 2, 4 ppm ozonated solution and saline showed mild superficial punctate keratitis (SPK) in 8.3% of eyes. However, 1.25% povidone-iodine resulted in mild SPK in 17% of eyes and moderate SPK in 25% of eyes. The prevalence of SPK between two groups was significantly different (p = 0.03). CONCLUSION: Ozonated solution may be safe and a useful antiseptic of the ocular surface prior to ophthalmic surgery.

Animals↗
PubMed2002

Human pharmacokinetic study of heated intraperitoneal oxaliplatin in increasingly hypotonic solutions after complete resection of peritoneal carcinomatosis.

PURPOSE: We studied the pharmacokinetics of heated intraoperative intraperitoneal (i.p.) oxaliplatin (LOHP) solution and its safety profile in increasingly hypotonic solutions. This is the first clinical study of i.p. chemohyperthermia with hypotonic solutions. METHODS: Patients with peritoneal carcinomatosis (PC) underwent complete cytoreductive surgery followed by intraoperative i.p. chemohyperthermia (IPCH) with successive dextrose solutions of 300, 200, 150 and 100 mosm/l. LOHP (460 mg/m(2)) was administered in 2 liters of solution/m(2) at an i.p. temperature of 42-44 degrees C for 30 min. IPCH was performed using an open procedure (skin pulled upwards) with a continuous closed circuit. Patients received intravenous leucovorin (20 mg/m(2)) and 5-fluorouracil (400 mg/m(2)) just before IPCH to maximize the effect of LOHP. i.p. plasma and tissue samples were analyzed by means of atomic absorption spectrophotometry. Sixteen consecutive patients with PC of either gastrointestinal or peritoneal origin were treated. The safety of the procedure was studied. RESULTS: Pharmacokinetics: The mean duration of the entire procedure was 7.7 +/- 2.6 h. Half the LOHP dose was absorbed within 30 min at all dose levels. Absorption was not higher with hypotonic solutions than with isotonic solutions. The area under the curve of LOHP in plasma did not increase with decreasing osmolarity of the i.p. solutions. Intratumoral LOHP penetration was high; it was similar to that at the peritoneal surface, and about 18 times higher than that in nonbathed tissues. LOHP penetration was not significantly increased by using hypotonic solutions. SAFETY: There was a very high incidence of unexplained postoperative peritoneal bleeding (50%) and unusually severe thrombocytopenia in the 150 and 100 mosm/l groups. CONCLUSION: Contrary to experimental studies, this clinical study showed no increase in tumoral or systemic penetration of LOHP with i.p. hypotonic solutions (200, 150 or 100 mosm/l) during IPCH. A high incidence of i.p. hemorrhage and thrombocytopenia was observed.

Antineoplastic Agents↗
PubMed2005

Mechanism of contraction of rat isolated tail arteries by hyposmotic solutions.

Contraction induced by hyposmotic swelling was examined in rat tail arteries mounted on a myograph containing a modified Krebs physiological saline solution (PSS) containing 50 mM mannitol (300 mosm/l). Hyposmotic swelling was induced by removing mannitol. In arteries having basal tone or arteries precontracted with K(+) or the thromboxane mimetic U-46619, removal of mannitol caused a concentration dependent contraction of rat tail arteries. Concurrent measurement of tension and intracellular calcium [Ca(2+)](i )in arteries loaded with fura-2 showed that both tension and [Ca(2+)](i) increased on exposure to a hyposmotic solution. Removal of endothelium or inhibition of nitric oxide and cyclooxygenase together did not affect contractile responses. Removal of extracellular Ca(2+) abolished the contractile response to hyposmotic solution and NiCl(2), a nonspecific inhibitor of Ca(2+) influx pathways, blocked the rise in [Ca(2+)](i) and tension in response to a hyposmotic solution. Verapamil and nisoldipine, inhibitors of Ca(v)1.2 (L-type) calcium channels significantly reduced the contractile response to a hyposmotic solution. Addition of NiCl(2) to nisoldipine caused an additional inhibition of the response to a hyposmotic solution. Inhibition of calcium release from the sarcoplasmic reticulum by ryanodine or cyclopiazonic acid (CPA) did not cause any change in the tension response to a hyposmotic solution. CPA did not significantly inhibit the response to a hyposmotic solution in the presence of N(G)-methyl-L-arginine, oxyhaemoglobin and indomethacin. We conclude that contraction induced by a hyposmotic solution is largely due to Ca(v)1.2 calcium channels although other Ca(2+) influx pathways also contribute.

Animals↗
PubMed1991

Microcirculatory dysfunction following perfusion with hyperkalemic, hypothermic, cardioplegic solutions and blood reperfusion. Effects of adenosine.

BACKGROUND: Cardioplegic solutions have been used to enhance myocardial preservation during cardiac surgery. The benefits derived from preventing myocardial ischemia with cardioplegic solutions may, however, be countered by tissue damage that occurs when the myocardium is reperfused with oxygenated blood. Furthermore, cardioplegia-induced endothelial dysfunction may contribute to depressed myocardial function postoperatively. The endothelium of coronary arteries and vein grafts is damaged by crystalloid cardioplegic solutions. There is less known about the effects of cardioplegic solutions on the microvasculature. METHODS AND RESULTS: The hypothesis that microvascular damage occurs following perfusion with hyperkalemic, crystalloid, cardioplegic solutions and blood reperfusion, leading to decreased blood flow and increased neutrophil accumulation, was tested in a model system. Intravital microscopic observations were performed during a 20-minute perfusion of the hamster cremaster muscle with cardioplegic solutions (10 degrees C) via the femoral artery with the iliac occluded and during a subsequent 2-hour blood reperfusion period (iliac open). Arteriolar vasoconstriction (27% decrease in diameter, p less than 0.05) and a 25% decrease in the density of perfused capillaries (p less than 0.05) occurred during reperfusion in hamsters receiving crystalloid cardioplegic solution (16 meq K+) compared to control hamsters (no cardioplegic solution given). Neutrophils accumulated on venular endothelium in treated animals (250% increase, p less than 0.05) and extravascularly (myeloperoxidase levels 2.0 +/- 0.4 U/g versus 1.3 +/- 0.3 U/g in control, p less than 0.05). The addition of adenosine (10(-4) M) and albumin (2 g%) to the cardioplegic perfusate, accompanied by the administration of adenosine (10(-4) M) during reperfusion, produced arteriolar vasodilation (34% diameter increase, p less than 0.05) and inhibited extravascular neutrophil accumulation (myeloperoxidase level of 1.5 +/- 0.2 U/g, p greater than 0.05 versus control). Capillary perfusion, however, was still significantly diminished (28% decrease, p less than 0.05.) CONCLUSIONS: We conclude that injury manifest by decreased microvascular blood flow and increased neutrophil accumulation in tissues occurs after perfusion with hypothermic, hyperkalemic, crystalloid cardioplegic solutions and blood reperfusion. Adenosine seems to partially attenuate this injury by dilating arterioles and decreasing extravascular neutrophil accumulation.

Adenosine↗
PubMed1982

Potentiating and depressive effects of ouabain and potassium-free solutions on rat mesenteric resistance vessels.

We have investigated the in vitro effects of ouabain and K-free solutions on some pharmacological and electrophysiological properties of rat mesenteric resistance vessels (internal diameter approximately 190 micrometers). Vessels were mounted as ring preparations on a myograph capable of measuring their isometric wall tension. In normal saline solutions, vessels did not exhibit any tone and had a membrane potential of -54 mV. Both 1 mM ouabain and K-free solutions caused a transient depolarization of 5-8 mV; thereafter the membrane slowly depolarized to about -45 mV after 30 minutes. There was no mechanical response to ouabain, but K-free solutions caused a transient development of tension which could be inhibited by phentolamine (1 microM). In norepinephrine-activated vessels, exposure to ouabain or K-free solutions caused a small depolarization and an increase in tension. Long-term (30-minute) exposure to 1 mM ouabain or K-free solutions reduced the amplitude of norepinephrine responses and, for the lower (but not the higher) norepinephrine concentrations, the membranes were about 14 mV more depolarized than control. The mechanical responses to a cocktail of norepinephrine in a high potassium solution were, however, unaffected. Re-exposure to normal saline solution produced a transient hyperpolarization and transiently eliminated the norepinephrine response, but thereafter the membrane potential and response returned to normal. The results indicate that ouabain and K-free solutions can have both short-term potentiating and long-term depressive effects on the mechanical response of rat mesenteric resistance vessels to norepinephrine.

Animals↗
PubMed1981

Intravenous chlormethiazole- haemolysis with concentrated solutions.

Since the current clinical concentration of chlormethiazole solutions (0.8%) may require the infusion of large volumes of fluid, it was decided to examine the effects on haemolysis of infusing higher concentrations of chlormethiazole into a central vein. Approximately one gram of chlormethiazole was infused into the inferior vena cavae of six anaesthetised greyhounds over each half hour using, successively, 0.8%, 1.2%, 2%, 5%, 10%, and 20% solutions of chlormethiazole. Free plasma haemoglobin levels were measured at five minute intervals, and blood chlormethiazole levels at 15 minute intervals. A rapidly progressive haemolysis occurred when the 5 or 10% solutions were infused. In a further four greyhounds, one gram of chlormethiazole was infused over each half hour using a 0.8% solution, whilst progressively hyperosmolar dextrose solutions were infused at the same rates in succeeding half hours as the concentrated chlormethiazole solutions had been infused in the first six dogs. No haemolysis occurred in these control animals. Chlormethiazole blood levels were similar in each group. Loss of chlormethiazole into the infusion tubing was examined and found to be 20% for the 0.8% solution, and 10% for the 1.2% solution, but was insignificant with the other subsequently infused concentrations of chlormethiazole. It is concluded that rapid progressive haemolysis occurs in association with the infusion of chlormethiazole solutions when concentrations of greater than 5 or 10% are infused into the inferior vena cavae of anaesthetised greyhounds.

Anesthesia↗
PubMed1997

Degradation of a novel tripeptide, tert-butoxycarbonyl-Tyr-Leu-Val-CH2Cl, with inhibitory effect on human leukocyte elastase in aqueous solution and in biological fluids.

The stability of tert-butoxycarbonyl-Tyr-Leu-Val-CH2Cl (YLV) with inhibitory effect on human leukocyte elastase was investigated in aqueous solution, alpha-chymotrypsin solution and biological media. In all cases studied here, the degradation was observed as a pseudo-first order reaction. The half-life for the degradation of YLV in an aqueous solution of pH 7.4 at 37 degrees C was 35.9 h. YLV was most stable at about pH 3.8-5.8 and the effect of temperature was explained by the Arrhenius equation. The activation energies of the degradation in aqueous solutions at pH 2.0, 4.8, and 7.4 were 24.6, 22.1 and 23.4 kcal/mol, respectively. The degradation products in aqueous solution were analyzed by HPLC-MS and were estimated as Boc-Tyr-Leu-Val-CH2OH at pH 7.4 and H2N-Tyr-Leu-Val-CH2Cl at pH 2.0. In a bovine pancreas alpha-chymotrypsin solution at 37 degrees C, the half-life of YLV was 15 min at 25.6 micrograms/ml of alpha-chymotrypsin solution. In the rat plasma, the half-life of YLV was 42.4 min (YLV 26.7 micrograms/ml plasma), and in rat liver, lung and spleen homogenates, the degradation rate constants of YLV were 37.6, 10.3 and 23.5 times larger than that in plasma solution, respectively (all fluids containing 5 mg protein/ml). YLV was less stable than nafarelin acetate, secretin, adrenocorticotropic hormone (ACTH) and gonadorelin in an aqueous solution of pH 7.4.

Animals↗
PubMed2003

Anti-tack action of polyvinylpyrrolidone on hydroxypropylmethylcellulose solution.

The anti-tack action of polyvinylpyrrolidone (PVP) on hydroxypropylmethylcellulose (HPMC) solution was elucidated using a probe test method. The influence of PVP of varying molecular weights at various PVP concentrations and solution temperatures on the tackiness of HPMC solution was studied. The viscosity, surface tension, cloud point and solution spectroscopy of HPMC solutions and glass transition temperature of HPMC films, with and without PVP, were investigated. The tackiness of HPMC solutions in response to the addition of PVP, at different concentrations of HPMC and using HPMC with varying contents of hydroxypropyl/methoxyl substitution, was also evaluated. PVP is a commonly used binder and adhesive. However, it reduced the tack of the HPMC solution when used at low concentrations, without affecting the state of hydration of HPMC. Lower molecular weight PVP was more effective as an anti-tack agent owing to suitable hydrodynamic size to intersperse among the HPMC chains. The degree of reduction in tack values was more pronounced for HPMC that showed a greater extent of interaction between polymer chains such as when high concentration of HPMC or low solution temperature was employed. This indicated that the tack reduction property of PVP relied on its ability to interact with the HPMC chains. The profile of reduction in tack values was affected by the contents of HPMC substitution and was a result of net reduction in the extent of hydrogen bonding between HPMC chains. It was significantly correlated to the changes of viscosity and surface tension of the HPMC solutions but not to the glass transition temperatures of the polymers prepared as solid films. The results suggested that the anti-tack action of PVP was attributed to its ability to interact with HPMC chains in the aqueous medium and consequently to reduce the extent of HPMC-HPMC bonding.

Hypromellose Derivatives↗
PubMed2003

Effect of sodium tetraborate (borax) on the thermal properties of frozen aqueous sugar and polyol solutions.

The effect of sodium tetraborate (Na(2)B(4)O(7), borax) on the thermal property of frozen aqueous sugar and polyol solutions was studied through thermal analysis. Addition of borax raised the thermal transition temperature (glass transition temperature of maximally freeze-concentrated solutes; T(g)') of frozen sucrose solutions depending on the borax/sucrose concentration ratios. Changes in the T(g)' of frozen mono- and disaccharide solutions suggested various forms of complexes, including those of a borate ion and two saccharide molecules. Borax exerted the maximum effect to raise the oligosaccharide and dextran T(g)'s at borax/saccharide molar ratios of approximately 1-2 (maltose and maltooligosaccharides), 2 (dextran 1060), 5 (dextran 4900), and 10 (dextran 10200). Further addition of borax lowered T(g)'s of the saccharide solutions. Borax also raised T(g) and T(g)' temperatures of frozen aqueous glycerol solutions. The decreased solute mobility in frozen solutions by the borate-polyol complexes suggested higher collapse temperature in the freeze-drying process and improved stability of biological systems in frozen solutions.

Borates↗
PubMed2004

Stability of cefepime in icodextrin peritoneal dialysis solution.

BACKGROUND: Icodextrin is a glucose polymer used as an alternative osmotic agent in peritoneal dialysis (PD) solutions. Cefepime may be a suitable antibiotic for the treatment of PD-related peritonitis. The stability of cefepime in icodextrin PD solution has not been examined. OBJECTIVE: To determine the chemical stability of cefepime in icodextrin PD solution over a 7-day period. METHODS: Samples were prepared by adding cefepime HCl 1000 mg to commercially available 2.0-L bags of icodextrin 7.5% PD solution. Nine bags were prepared and stored in the following conditions: 3 under refrigeration (4 degrees C), 3 at room temperature (20 degrees C), and 3 at body temperature (37 degrees C). Study samples were drawn from each bag immediately after preparation and at predetermined intervals over the subsequent 7 days. Solutions were visually inspected for precipitation, cloudiness, or discoloration at each sampling interval. Total concentration of cefepime in dialysate fluid was determined by liquid chromatography-tandem mass spectrometry. RESULTS: Under refrigeration, a mean +/- SD of 95.7 +/-4.2% of the initial cefepime concentration remained at 168 hours (7 days). At room temperature, 92.0 +/- 17.9% remained at 48 hours. At body temperature, 92.2 +/- 4.7% remained at 4 hours. Beyond these respective time points, <90% of the initial cefepime concentrations remained. CONCLUSIONS: Pre-mixed cefepime-icodextrin PD solutions stored at room temperature were stable for up to 48 hours. However, it is recommended that these be kept refrigerated whenever possible. When refrigerated, cefepime-icodextrin solutions were found to be stable for up to 7 days. Solutions stored at body temperature were stable up to 4 hours, permitting the practice of pre-warming solutions prior to administration.

Anti-Bacterial Agents↗
PubMed2006

Stability of vancomycin in icodextrin peritoneal dialysis solution.

BACKGROUND: Icodextrin is a glucose polymer used as an alternative osmotic agent in peritoneal dialysis (PD) solutions. There are few data regarding the long-term stability of vancomycin in icodextrin PD solution. OBJECTIVE: To determine the chemical stability of vancomycin in icodextrin PD solution in polyvinyl chloride containers over a 7 day period at 4, 24, and 37 degrees C. METHODS: Study samples were prepared by adding 2000 mg vancomycin HCl to commercially available 2.0 L bags of icodextrin 7.5% PD solution. Nine bags were prepared and stored in the following conditions: 3 under refrigeration (5 degrees C), 3 at room temperature (24 degrees C), and 3 at body temperature (37 degrees C). Samples were withdrawn from each bag immediately after preparation and at predetermined intervals over the subsequent 7 days. Solutions were visually inspected for precipitation, cloudiness, or discoloration at each sampling interval. Total concentration of vancomycin in dialysate fluid was determined by high performance liquid chromatography. RESULTS: Under refrigeration, a mean +/- SD of 99.7% +/- 0.5% of the initial vancomycin concentration remained at 168 hours (7 days). At room temperature, 97.5% +/- 3.4% remained at 168 hours. At body temperature, 94.3% +/- 3.9% remained at 24 hours. Stability was not assessed beyond these time points. CONCLUSIONS: Premixed vancomycin-icodextrin PD solutions, whether stored refrigerated or at room temperature, were found to be stable for up to 7 days. However, we recommend that these solutions be kept refrigerated whenever possible. Solutions stored at body temperature were stable for up to 24 hours, permitting the practice of prewarming solutions prior to administration.

Dialysis Solutions↗
PubMed1996

Influence of hypertonic saline solution infusion on defibrillation efficacy.

Hypertonic saline solution may enhance cardiac conduction via the fast inward sodium channel and alter transmembrane Ca+2 conductance via the sodium-calcium exchanger. Evidence suggests that both Ca+2 conductance and myocardial conduction velocity may affect ventricular defibrillation. Since hypertonic saline solution solutions (ie, sodium bicarbonate) may be administered to patients who have conditions that often require ventricular defibrillation (ie, cardiac arrest or hypovolemic shock), we studied the effect of hypertonic saline solution on the defibrillation threshold (DFT) in 16 pentobarbital-anesthetized domestic farm swine (20 to 30 kg). Defibrillation was performed using two interfaced epicardial electrode patches. DFTs were determined at baseline and during treatment phase. Pigs were randomly assigned to treatment consisting of either hypertonic saline solution (6 mmol/kg load, 2.0 to 3.0 mmol/kg infusion) to maintain serum sodium concentrations 10 to 15 mmol/L above baseline or control (D5W given in equal volume). DFT values (joules) that predicted 50% success were modeled from a best-fit histogram. Hypertonic saline solution did not change DFT values from baseline values (10.2 +/- 4.3 vs 10.8 +/- 7.0, respectively). Likewise, placebo (D5W) did not change DFT values from baseline values (10.1 +/- 4.5 vs 11.3 +/- 4.3). During treatment phase, DFT values were 99 +/- 28% of baseline values in the hypertonic saline solution group and 116 +/- 23% of baseline values in the D5W groups (p = 0.21). The administration of hypertonic saline solution also did not affect ventricular conduction velocity, right ventricular action potential duration, or right ventricular effective refractory period. These data indicate that hypertonic saline solution does not appreciably affect defibrillation efficacy or electrical treatment of ventricular fibrillation.

Animals↗
PubMed2001

Induced sputum: comparison between isotonic and hypertonic saline solution inhalation in patients with asthma.

BACKGROUND: Sputum induction by hypertonic saline solution inhalation is widely used to study airways secretions in patients with asthma. However, hypertonic saline solution is a potent indirect bronchoconstrictor. STUDY OBJECTIVES: We studied the validity of isotonic saline solution (0.9%) inhalation as a means to induce sputum by comparing it to hypertonic saline solution (4.5%) inhalation. PATIENTS: Sixteen patients with moderate-to-severe asthma reporting a clinical history of mucus hypersecretion. METHODS: Subjects underwent sputum induction twice at 1-week intervals. Saline solution (hypertonic or isotonic) was inhaled for three periods of 5 min. The parameters assessed in sputum samples were cell counts, sodium, eosinophil cationic protein (ECP), and albumin concentrations, osmolality, and pro-matrix metalloproteinase (MMP)-9 activity by zymography. RESULTS: The maximal fall in peak expiratory flow during sputum induction was greater after inhalation of hypertonic saline solution than after inhalation of isotonic saline solution (p < 0.01). Each subject produced analyzable sputum on both visits. There were no statistically significant differences in total and differential sputum cell counts, and the reproducibility coefficients were high for eosinophils and neutrophils when comparing the two methods. Likewise, sputum levels of ECP and albumin as well as sputum pro-MMP-9 activity were not different between the two methods, and were highly reproducible as shown by high intraclass coefficients (Ri) of correlation (0.72, 0.74, and 0.77 for ECP, albumin, and pro-MMP-9, respectively). Sputum sodium concentrations and osmolality were higher after inhalation of hypertonic saline solution (p < 0.05). CONCLUSION: In patients with moderate-to-severe asthma reporting a clinical history of mucus hypersecretion, inducing sputum by isotonic or hypertonic saline solution inhalation leads to comparable results in eosinophil and neutrophil cell counts and fluid phase mediators/proteins.

Administration, Inhalation↗
PubMed2001

Better preservation of peritoneal morphologic features and defense in rats after long-term exposure to a bicarbonate/lactate-buffered solution.

The long-term effects of a standard lactate-buffered dialysis fluid and a new, two-chamber, bicarbonate/lactate-buffered dialysis fluid (with fewer glucose degradation products and a neutral pH) were compared in an in vivo peritoneal exposure model. Rats were given daily injections, via an access port, of 10 ml of standard solution or bicarbonate/lactate-buffered solution for 9 to 10 wk. The omentum, peritoneum, and mesothelial cell layer were screened for morphologic changes. In addition, the bacterial clearing capacity of the peritoneal cells was studied. Significantly more milky spots and blood vessels were observed in the omenta of animals treated with standard solution (P < 0.03 for both parameters). Electron-microscopic analysis demonstrated dramatic changes in the appearance of the vascular endothelial cells of the milky spots and a severely damaged or even absent mesothelium on the peritoneal membrane of the standard solution-treated animals. In contrast, the mesothelium was still present in the bicarbonate/lactate-buffered solution group, although the cells lost microvilli. Both peritoneal dialysis fluids significantly increased the density of mesothelial cells (per square millimeter) on the surface of the liver and the thickness of the submesothelial extracellular matrix of the peritoneum (both P < 0.04 for both fluids versus control). A significantly better ex vivo bacterial clearing capacity was observed with peritoneal cells from the bicarbonate/lactate-buffered solution group, compared with the standard solution group (P < 0.05 in both experiments). These results demonstrate that instillation of bicarbonate/lactate-buffered solution into rats for 9 to 10 wk preserves both morphologic and immune parameters much more effectively, compared with standard solution. These findings may be of considerable clinical importance.

Animals↗
PubMed1992

Modified hemoglobin solution as possible perfusate relevant to organ transplantation.

A modified hemoglobin solution ( - conjugate solution, PHP solution) has very interesting characteristics such as oxygen-carrying property without corpuscular components. Experimental use of the PHP solution has shown promising possibilities as a perfusate relevant to organ transplantations. 1) Elongation of warm ischemic time in canine kidneys: Dogs survived even with the unilateral kidneys which had been exposed up to 4.5 hour warm ischemia and, thereafter, perfused with the PHP solution. 2) Elongation of perfusion preservation period of canine livers: Dogs survived with the transplanted livers which had been perfused for 48 hours with the PHP solution. 3) Successful perfusion of rat small intestine: Lewis rat intestines perfused and preserved for 12 hours with the PHP solution showed a higher survival rate compared with those with Collins or UW solution. 4) Removal of antibodies: By exchange transfusion with a total of 30-60 ml of the PHP solution, a Lewis rat hematocrit lowered to 5% while IgG went down to nil from 8970 mg/dl, IgA to 28 mg/dl from 118 mg/dl and IgM to 190 mg/dl from 897 mg/dl. This technique is expected to be applicable for removal of the naturally existing antibodies in xenotransplantation.

Animals↗
PubMed1995

Experimental studies on the toxicity of lithographic developer solution.

The purpose of this study was to determine whether the toxicity of a lithographic developer solution which contains hydroquinone is caused by hydroquinone or the alkaline lithographic developer solution. Male Wistar rats were divided into seven groups. In four groups, rats were dosed orally with 3% hydroquinone or 3% hydroquinone in 3% lithographic developer solution. Hydroquinone levels were measured after one and 24 hours. In two groups, rats were dosed orally with 6% hydroquinone or 6% hydroquinone in lithographic developer solution. In the seventh group, rats received the alkaline solution only. Hydroquinone measurement was made using gas chromatography-mass spectrometry. Hydroquinone was rapidly absorbed from the gastrointestinal tract and subsequently distributed throughout the body. Nearly all hydroquinone was excreted in the urine as either a glucuronide or a sulfate (78-82%) within 24 hours. All rats administered 6% hydroquinone in non-alkaline vehicle died, but the mortality rate of rats administered 6% hydroquinone in lithographic developer solution was 60%. Tissue hydroquinone was lower at one hour and 24 hours after administration in lithographic developer solution than in equal dose of hydroquinone in non-alkaline vehicle suggesting decreased absorption in an alkaline pH. Hydroquinone was not associated with gross pathologic changes of the intestine but all animals treated with lithographic developer solution or alkaline solution had congestion, hemorrhagic petechiae and purple-brown discoloration throughout the small intestine. The combination of alkaline/formaldehyde diluent with hydroquinone may delay hydroquinone absorption but increase the risk of intestinal necrosis.

Animals↗
PubMed1998

Factors affecting dimensional instability of alginate impressions during immersion in the fixing and disinfectant solutions.

To clarify the factors determining the dimensional stability of alginate impressions during immersion in disinfectant and fixing solution, the weight change of impressions in solutions of glutaraldehyde (GA), NaClO, Na2SO4, K2SO4, CaCl2, and ZnSO4 was measured. In the nonelectrolytic solution, GA, the weight decreased in proportion to concentration, possibly due to the gradient of osmotic pressure between the impression and solution. In monovalent metallic salt solutions the weight change decreased with increased concentration. Especially at lower concentrations the rate of weight loss was high. A chemical action of the solution might also be involved, in addition to the osmotic pressure difference. The weight loss in divalent metallic salt solutions was greater than in monovalent solutions, implicating crosslinking reactions between the impression and solution.

Alginates↗