Reduction In Fluid Volume Research Articles

Artificial Collapse of Blastocysts Before Vitrification: Mechanical vs. Laser Technique and Effect on Survival, Cell Number, and Cell Death in Early and Expanded Blastocysts

The purpose of this study was to systematically examine blastocoelic fluid reduction prior to vitrification and its potential benefits. In addition, we compared artificial collapse (AC) by laser pulse to a mechanical method. Mouse and dicarded human blastocysts were used in this study. Blastocysts were collapsed using either a 10 ms pulse with a laser (LAC) or else mechanical puncture with a microneedle (MAC). Blastocysts were vitrified on cryoloops using a two-step ethylene glycol/dimethyl sulfoxide protocol. We examined the effects of AC on specific outcome parameters such as overall survival, reexpansion, cell proliferation, and DNA damage. Unlike others, we report overall high survival rates with expanded blastocysts even without fluid reduction. We did detect a significant increase in blastomeres showing signs of DNA damage in the control group (13%) in comparison to blastocysts AC prior to vitrification (LAC 3%, MAC 5%; p < 0.001). Control blastocysts exhibited a lower rate of reexpansion. Within 3 h of warming, 73% and 81%, respectively of mechanically or laser collapsed blastocysts were fully reexpanded as compared to only 53% of control blastocysts (p < 0.001). Overall blastomere count was also significantly lower in control blastocysts (CT 103+32, MAC 121 + 37, LAC 134 + 35; p < 0.0001). Early blastocysts with smaller blastocoelic volumes did not benefit from any further reduction of fluid volume. AC can reduce DNA damage and enhance postwarming reexpansion and cell proliferation in expanding blastocysts. The laser method also appeared to be effective and may offer some advantages over mechanical collapse.

Lower body positive pressure increases upper airway collapsibility in healthy subjects

We previously showed that rostral fluid displacement by lower body positive pressure (LBPP) narrows the upper airway (UA) and increases UA resistance, but effects on UA collapsibility remained unknown. To test if LBPP increases UA collapsibility, 13 healthy men were randomized into a control or LBPP arm then crossed over into the other arm with a 30-min washout in between. LBPP was applied by inflating anti-shock trousers wrapped around both legs to 40 mmHg. UA collapsibility was assessed by determining UA critical closing pressure (P crit) during application of different negative airway pressures. P crit and leg fluid volume were measured at baseline and after 5 min during both periods. LBPP caused a significant increase in P crit associated with a reduction in leg fluid volume. We conclude that rostral fluid displacement by LBPP increases UA collapsibility in healthy men, suggesting that fluid shift into the neck could increase UA collapsibility during sleep and thereby predispose patients with fluid overload states to obstructive sleep apnea.

Poster 59: Clinical Improvements in a Patient With Normal Pressure Hydrocephalus Status Post Lumbar Puncture and Ventriculoperitoneal Shunt Placement

Objectives: To describe, in a patient with normal pressure hydrocephalus (NPH), the clinical response to a diagnostic lumbar puncture, and to report on the stability of this response over time, after permanent ventriculoperitoneal (VP) shunt placement. Design: Single-case study: within-subject, repeated measures at 3 time points: preintervention, postintervention, and long-term follow-up. Setting: Outpatient physical therapy (PT) and medical clinics at a spinal cord injury center. Participant: A 74-year-old white man, presented with bradykinesia and flat affect. He complained of balance impairments, gait disturbance, and memory loss, and was diagnosed with NPH. He had a VP shunt placed on April 11, 2005, then fell on April 13, 2005, while still an inpatient, and fractured his right femoral neck, requiring internal stabilization with hardware. He also developed a VP shunt infection, requiring its removal on August 23, 2005. During this period post-shunt removal, he received PT intervention 3 times a week at this clinic, from September 12, 2005 until December 13, 2005, to address endurance, functional skills (eg, bed mobility, transfers), and gait training. At this time, he was using a manual wheelchair, with caregiver assistance, for all functional mobility tasks. The subject had a permanent VP shunt placed in February 2006. His history was also remarkable for pneumonia, infections, congestive heart failure, myocardial infarction, history of pacemaker placement, and chronic atrial fibrillation. Intervention: Lumbar puncture (LP) with resulting reduction of cerebrospinal fluid volume on November 10, 2005. Main Outcome Measures: Gait analysis (temporospatial) using GAITRite system, Berg Balance Scale (BBS), video of ambulation, Mini-Mental State Examination (MMSE), and the Minnesota Test of Hand Function. These outcome measures were performed the day before the LP, and within hours after the procedure. For long-term follow-up, the measures were to be repeated 14 months after he underwent permanent VP shunt placement. Results: Comparing pre- and post-lumbar puncture measures, the subject’s cadence increased from 85.1 to 110.7 steps/min (30% increase) (age norm, 104 steps/min). Velocity increased from 21.2 to 41.9cm/s (a 98% increase) (age norm, 108.7cm/s). Step length of the left leg increased from 23.2 to 27.8cm (a 20% increase) and step length of the right leg increased from 7.4 to 18.6 (a 148% increase) (age norm, 60cm). Stride lengths of the right and left legs increased from 31.2 to 47.3cm (a 53% increase) and from 31.6 to 48.3cm (a 52% increase), respectively. Age norm for stride length is 119cm. BBS score increased from 18/56 (pre-LP) to 32/56 (post-LP) (age norm, 56/56). Interpretation of BBS: 0 to 20 is wheelchair bound; 21 to 40 is walking with assistance; and 41 to 56 is independent. These results of the study are ongoing; long-term follow-up data on gait analysis and balance will be discussed. The MMSE score increased from 22/30 (pre-LP) to 24/30 (post-LP) (age norm, 28/30). On the Minnesota Test of Hand Function, his time pre-LP was 2:20.87 and his post-LP was 1:42.69. Conclusions: Preliminary results show meaningful changes in gait, including velocity, cadence, step and stride lengths, as well as standard measures of balance and cognitive function. In this case, LP had an immediate impact on his function, and may be useful in predicting outcomes of permanent VP shunt placement.

Prediction and Prevention of Abnormal Antenatal Lung Growth

Pulmonary hypoplasia, the result of abnormal antenatal lung growth, occurs as a primary anomaly or more usually the consequence of disorders resulting in reduction of amniotic fluid volume, intra-thoracic space or fetal breathing movements. Two dimensional (2D) ultrasound examination yields useful information on amniotic fluid volume and the presence of congenital abnormalities associated with pulmonary hypoplasia. Assessment of the thoracic or lung size by 2D ultrasound examination, is insufficiently specific, but a very low lung to head ratio predicts a fatal outcome in fetuses with congenital diaphragmatic hernia (CDH). Three-D ultrasound examination provides information on fetal lung volume prior to 34 weeks of gestation but can be inaccurate if there is oligohydramnios. Magnetic resonance imaging is expensive and has limited patient acceptability. Antenatal interventions attempted to prevent pulmonary hypoplasia include amnioinfusion, which can facilitate ultrasound examination, but only temporarily relieves oligohydramnios. Thoraco-amniotic shunting results in effective drainage of pleural effusions, facilitating resuscitation, but is usually performed too late in pregnancy to influence lung growth. In utero surgical repair of CDH has been attempted, but a more promising technique is obstruction of the normal egress of fetal lung fluid by placing a balloon in the trachea. Keywords: Pulmonary hypoplasia, lung growth, congenital diaphragmatic hernia, oligohydramnios, ultrasound, magnetic resonance imaging

A population based study of intracranial arachnoid cysts: clinical and neuroimaging outcomes following surgical cyst decompression in adults

Background:We have gradually adopted a liberal attitude towards surgical decompression of arachnoid cysts. This study describes the results from our institution.Methods:Long term clinical and neuroimaging results of 156 adult patients...

Vasopressin administration facilitates fluid removal during hemodialysis

Inadequate secretion of vasopressin during fluid removal by hemodialysis may contribute to the cardiovascular instability that complicates this therapy and administration of exogenous hormone, by supporting arterial pressure, may facilitate volume removal. To test this, we measured plasma vasopressin in patients with end-stage renal disease (ESRD) during hemodialysis and found that despite significant fluid removal, plasma vasopressin concentration did not increase. We further found that ESRD did not alter the endogenous removal rate of plasma vasopressin and that plasma hormone is not dialyzed. Finally, in a randomized, double-blinded, placebo-controlled trial in 22 hypertensive patients, we examined the effect of a constant infusion of a non-pressor dose of vasopressin on the arterial pressure response during a hemodialysis in which the target fluid loss was increased by 0.5 kg over the baseline prescription. We found that arterial pressure was more stable in the patients receiving vasopressin and that while only one patient (9%) in the vasopressin group had a symptomatic hypotensive episode, 64% of the patients receiving placebo had such an episode (P=0.024). Moreover, increased fluid removal was achieved only in the vasopressin group (520+/-90 ml vs 64+/-130 ml, P=0.01). Thus, administration of non-pressor doses of vasopressin to hypertensive subjects improves cardiovascular stability during hemodialysis and allows increased removal of excess extracellular fluid. Inadequate vasopressin secretion during hemodialysis-induced fluid removal is a likely contributor to the intradialytic hypotension that limits fluid removal.

Mechanism and Rate of Middle Ear Fluid Absorption

Several mechanisms have been suggested to explain the clearance of fluids from the middle ear. These include a pumping action through the eustachian tube, mucociliary beating through the tube, outflow of water to the blood due to osmotic gradients and an active Na⁺ transport driving water absorption. In order to assess these mechanisms, the middle ear cavity of paralyzed, ventilated (eustachian tube occluded) guinea pigs was filled with fluids varying in osmotic pressure (hypotonic, isotonic, hypertonic) to which a vertical tube was attached. The change in height of fluid in the tube was taken as a measure of changes in middle ear fluid volume. A greater fluid volume reduction was seen with the hypotonic (1/5 saline) solution. A small volume increase was observed with the hypertonic solution. These results provide evidence that in these experimental conditions, water absorption due to osmotic gradients can contribute to middle ear fluid clearance.

Effect of Various Diuretic Treatments on Rosiglitazone-Induced Fluid Retention

The efficacy of diuretics in the management of rosiglitazone (RSG)-induced fluid retention was evaluated in a multicenter, randomized, open-label, parallel-group, proof-of-concept study. Of 381 patients who had type 2 diabetes and were on treatment with sulfonylurea or sulfonylurea plus metformin, 260 (63% male, 37% female) showed evidence of volume expansion as defined by an absolute reduction in hematocrit (Hct) of > or =0.5% after 12 wk of rosiglitazone 4 mg twice daily. They were randomly assigned to five treatments for 7 d: (1) Continuation of RSG (RSG-C), (2) RSG + furosemide (RSG+FRUS), (3) RSG + hydrochlorothiazide (RSG+HCTZ), (4) RSG + spironolactone (RSG+SPIRO), and (5) discontinuation of RSG. The primary end point was change in Hct at day 7 of diuretic treatment phase, powered to compare each diuretic group and the RSG discontinuation with the control group of RSG-C, with adjustments for multiple testing. After 12 wk on RSG, Hct fell by mean of 2.92% (95% confidence interval [CI] -3.10 to -2.63%; P < 0.001) and extracellular fluid volume increased by 0.62 L/1.73 m(2) (95% CI 0.26 to 0.90 L/1.73 m(2); P < 0.001). After treatment, the RSG+SPIRO group only showed a mean increase in Hct of 0.24%. The estimated mean difference in Hct reduction was significant: 1.14% (95% CI 0.29 to 1.98%) for RSG+SPIRO (P = 0.004) and 0.87% (95% CI 0.03 to 1.71%) for RSG+HCTZ (P = 0.041) only. In additional analyses of between-diuretic treatment effects SPIRO induced a greater Hct rescue at 0.88% (95% CI -0.12 to 1.87%; P = 0.095) and extracellular fluid volume reduction of -0.75 L/1.73 m(2) (95% CI -1.52 to 0.03 L/1.73 m(2); P = 0.06) compared with FRUS, suggesting superiority in the management of RSG-associated fluid retention. There were no significant differences between SPIRO and HCTZ. These findings are consistent with peroxisome proliferator-activated receptor-gamma agonist activation of the epithelial sodium channel in the distal collecting duct, a site of action of SPIRO and a potential target for thiazide diuretics.

Antiulcer and in vitro antioxidant activities of Jasminum grandiflorum L.

The study was aimed at evaluating the antiulcer and antioxidant activities of 70% ethanolic axtract of leaves of Jasminum grandiflorum L. (JGLE). The leaves of Jasminum grandiflorum L. (Family: Oleaceae) is used in folk medicine for treating ulcerative stomatitis, skin diseases, ulcers, wounds, corns—a hard or soft hyperkeratosis of the sole of the human foot secondary to friction and pressure (Stedman's Medical Dictionary, 28th ed. Lippincott Williams & Wilkins, Philadelphia. p. 443), etc., Antiulcerogenic activity of JGLE (100 and 200 mg/kg, b.w., orally) was evaluated employing aspirin + pylorus ligation (APL) and alcohol (AL) induced acute gastric ulcer models and ulcer-healing activity using acetic acid-induced (AC) chronic ulcer model in rats. Both the antisecretory and cytoprotection hypothesis were evaluated. The antioxidant activity of JGLE has been assayed by using in vitro methods like 2,2-diphenyl-1-picrylhydrazylhydrate (DPPH) assay, reductive ability, superoxide anion scavenging activity, nitric oxide scavenging activity and total phenolic content, in order to explain the role of antioxidant principles in the antiulcerogenic activity of the extract. There was a significant ( P < 0.01) dose-dependent decrease in the ulcerative lesion index produced by all the three models in rats as compared to the standard drug famotidine (20 mg/kg, b.w. orally). The reduction in gastric fluid volume, total acidity and an increase in the pH of the gastric fluid in APL rats proved the antisecretory activity of JGLE. Additionally, JGLE completely healed the ulcer within 20 days of treatment in AC model as evidenced by histopathological studies. Like antiulcer activity, the free radical scavenging activities of JGLE depends on concentration and increased with increasing amount of the extract. These results suggest that leaves of Jasminum grandiflorum possess potential antiulcer activity, which may be attributed to its antioxidant mechanism of action.

Fluid Shift by Lower Body Positive Pressure Increases Pharyngeal Resistance in Healthy Subjects

Fluid displacement into nuchal and peripharyngeal soft tissues while recumbent may contribute to narrowing and increased airflow resistance of the pharynx (Rph), and predispose to pharyngeal collapse in patients at risk for obstructive sleep apnea. To determine whether displacement of fluid from the lower body to the neck will increase both neck circumference and Rph in healthy subjects. In 11 healthy, nonobese subjects, studied while awake and supine, leg fluid volume, neck circumference, and Rph were measured at baseline. Subjects were then randomized to a control period or to application of lower body positive pressure (LBPP) of 40 mm Hg via antishock trousers to displace fluid from the legs, after which they crossed over to the other arm. Baseline measurements were repeated at 1 and 5 min during the control and LBPP periods. Compared with the control period, application of LBPP caused a significant reduction in leg fluid volume (p < 0.001) and a significant increase in neck circumference (p = 0.004). Rph remained stable during the control period, but increased significantly from baseline after 1 and 5 min of LBPP (from 0.43 +/- 0.10 to 0.60 +/- 0.11 cm H(2)O/L/s, p = 0.034, and to 0.87 +/- 0.19 cm H(2)O/L/s, p < 0.001, compared with baseline, respectively). Fluid displacement from the legs by LBPP increases neck circumference and Rph in healthy subjects. These findings suggest the hypothesis that fluid displacement to the upper body during recumbency may predispose to pharyngeal obstruction during sleep, especially in fluid overload states, such as heart and renal failure.

P05.04: Vascular resistance changes during amnioreduction in TTTS

Our purpose was to investigate whether acute alterations of amniotic fluid volume affect fetal circulation in twin-to-twin transfusion syndrome (TTTS). The study group included 7 pairs of twin pregnancies complicated by TTTS. The alterations of pulsatility index (PI) in the umbilical artery and in the middle cerebral artery during 25 amnioreductions were evaluated. Color Doppler imaging was used to measure the changes of vascular resistance before and after the procedure. The PI values before and after amnioreduction were compared. The duration of procedure depended on the amniotic fluid volume removed during amnioreduction. Amniotic fluid volume reduction was carried out as long as normal value of maximal amniotic packet (MAP 2.0–8.0 cm) was achieved. The table presents the comparison of PI values in certain fetal vessels (UA and MCA) in the larger and smaller twin, as well as PI differences between twins before and after amnioreduction. Amnioreduction causes significant changes of blood flow resistance altering fetal circulation. In twin to twin transfusion syndrome the reduction of blood flow resistance in the umbilical artery may improve fetal condition and partially explain the success of serial amnioreduction therapy. Moreover, the assessment of blood flow changes in the MCA helps to choose optimal treatment. Supported by KBN 2 PO5E03027.

Reduction of amniotic and allantoic fluid volume in an ovine model of fetal growth restriction

Reduction of amniotic and allantoic fluid volume in an ovine model of fetal growth restriction

An Observational Study On The Spectrum Of Heat-Related Illness, With A Proposal On Classification

During operations in subtropical areas over the summer months of 2001 and 2003 the authors audited 80 patients with heat-related illness, with the intention of defining the nature and distribution...

Regulation of amniotic fluid volume: Intramembranous solute and volume fluxes in late gestation fetal sheep

Objective Recent studies suggest that amniotic fluid volume is regulated by the rate of intramembranous absorption of amniotic fluid into fetal blood. The purpose of the present study was to determine the simultaneous intramembranous solute and water fluxes to gain insight into the intramembranous transport and amniotic fluid volume regulatory mechanisms. Study design All major amniotic inflows and outflows, except intramembranous flow, were eliminated in 10 fetal sheep over 8 hours by occlusion of the fetal trachea and esophagus; the fetal urine was drained to the exterior. Amniotic fluid composition and volume were measured before and at the end of the 8 hours. Solute and volume fluxes through the intramembranous pathway were calculated from amniotic fluid concentration and volume changes. Statistical analyses included t-tests, linear regression, and analyses of variance. Results Amniotic fluid volume decreased by 128 ± 24 (SE) mL over 8 hours ( P < .001), which was correlated only marginally with the fetal to amniotic fluid osmotic gradient (r = 0.59; P >= >.072). Amniotic fluid sodium, chloride, calcium, and bicarbonate concentrations increased ( P < .0001), even though there were net outward fluxes of these solutes; these outward fluxes occurred against concentration gradients; and the clearances of these solutes were the same despite widely differing amniotic fluid concentrations and fetal blood to amniotic fluid concentration gradients. With the use of multivariate regression, intramembranous solute fluxes separated into 2 components, which were a primary outward flux that correlated with the volume flux and a minor inward component that correlated with the fetal plasma to amniotic fluid concentration gradient for sodium, chloride, calcium ( P < .001), and bicarbonate ( P < .02). The concentration-dependent fluxes averaged approximately one third of the bulk fluxes and were in the opposite direction. Conclusion The poor correlation of amniotic fluid volume reduction with the fetal-to-amniotic fluid osmotic gradient shows that the primary mechanism that mediates intramembranous volume flow is not passive osmosis in the normal fetus under basal conditions. The strong correlations of solute fluxes simultaneously with volume flux and concentration gradients suggest that intramembranous solute fluxes are mediated by both bulk flow and passive diffusion. The small size of the passive component relative to the size of the bulk component suggests that intramembranous solute transfer is mediated primarily by bulk flow with a smaller and usually oppositely directed contribution by diffusion down concentration gradients. Bulk flow by vesicular transport is the only known physiologic transport mechanism that is compatible with these data, but it is not known whether this occurs in the amnion or intramembranous blood vessels or both.

Serial assessment of amniotic fluid index in uncomplicated term pregnancies: prognostic value of amniotic fluid reduction

Objective: Assessment of amniotic fluid volume in association with a non-stress test is a commonly used method to monitor fetal well-being in high-risk pregnancies. The aims of our study were to determine whether oligohydramnios and the trend in amniotic fluid volume have prognostic significance in low-risk pregnancies between 40.0 and 41.6 weeks' gestation.Methods: Between January 1997 and December 2000, all uncomplicated gestations with a singleton non-anomalous fetus reaching 40.0 weeks' gestation underwent semi-weekly monitoring of amniotic fluid index (AFI) until delivery. Oligohydramnios was defined as an AFI of ⩽ 5 cm. Changes in AFI were expressed as centimeters per day, and were calculated as: [(last AFI before delivery minus first AFI at 40.0 weeks) / interval in days between the two scans]. Adverse outcome was considered the occurrence of 5-min Apgar score < 7; umbilical artery pH < 7.0; Cesarean section for fetal distress; or fetal death. Comparisons between the groups with favorable and adverse outcomes was performed with χ2 or Fisher's exact test for categorical variables, and Student's t test for continuous variables. A two-tailed p value < 0.05 was considered significant.Results: A total of 3050 women met the study criteria, and underwent a median number of two (range 1–7) sonographic assessments of AFI after 40.0 weeks, with oligohydramnios detected in 341 women. In 1466 women at least two serial AFI determinations were obtained, allowing computation of an AFI trend. Gestations resulting in adverse perinatal outcome (n = 167, 5.5%) had a significantly higher rate of oligohydramnios (33/167, 19.8% vs. 308/2883, 10.7%, p = 0.001), but a similar rate of reduction in AFI ( − 0.65 ± 0.64 vs. – 0.66 ± 0.66 cm/day; p = 0.85) than those with favorable outcome. The difference in rate of reduction of AFI between the two groups was not significant, even in the subset of gestations that developed oligohydramnios ( − 1.08 ± 0.87 vs. – 1.26 ± 0.89 cm/day; p = 0.27).Conclusion: A sonographic diagnosis of oligohydramnios carries an increased risk of adverse perinatal outcome, even in low-risk pregnancies after 40 weeks. The trend in amniotic fluid volume reduction does not seem to have prognostic significance.

Effects of weight loss induced by gastric surgery on left ventricular mass and blood pressure in severe obese patients

To assess the effects of weight loss induced by bariatric surgery on left ventricular mass (LVM), 24-hour blood pressure profile, and metabolic parameters in obese patients. Before and 6 months after a bariatric surgery for weight loss, echocardiography to assess the LVM and 24-hour ambulatory blood pressure monitoring (ABPM) were performed in 27 obese patients, 24 females / 3 males, body mass index (BMI) = 50,7 ± 6,1 Kg/ m2. Hemoglobin, serum albumin, glucose, lipid profile and liver enzymes levels were determined before and 6 months after surgery. BMI was significantly reduced from 50,7 ± 6,1 Kg/ m2 to 38,1 ± 3,3 Kg/ m2 (31,5% of the initial weight; p < 0.001). Left ventricular mass reduced from 201 ± 58,2 to 176 ± 60,6 g or 12,5 %; p < 0,01. Also the mean systolic blood pressure (SBP) (from 124 ± 10,2 to 113 ± 12,6 mmHg; p<0,001) and the mean diastolic blood pressure (DBP) (from 72,5 ± 7,7 to 68,9 ± 8,41mmHg; p< 0,03) were reduced. The percentage SBP fall during sleep did not change (-8.0±5.0 to -8.7±4.2%). There were no correlations between the changes in LVM and the changes in weight loss, SBP and DBP. Significant reductions were observed in blood glucose (from 96.8±26.3 to 78.1± 12.5 mg/dl; p<0,01), total- cholesterol (from 217.2±55.2 to 201.2± 55.0 mg/dl; p<0,01), and LDL-cholesterol (from 165.3±9 8.0 to 125.7± 46.5 mg/dl; p<0,02) but not in triglycerides levels (from 142.6± 99.7 to 124.2±80.2; p>0,05). HDL-cholesterol was significantly increased (from 42.8±8.3 to 50.6±12.7; p<0,01). Serum hemoglobin (13.2±1.7 vs 12.8±1.9 g/dl; p>0,05) and serum albumin (3.8± 0.3 vs 3.9± 0.3 g/dl; p>0,05) were not changed while alkaline phosphatase, but no other liver enzymes, increased significantly after surgery from144.0± 84.3 to 213 ± 57,9 g/dl; p=0,02.Concluding, bariatric surgery induced significant weight loss, decreases in LVM and 24h-ABPM, glucose, total-cholesterol and LDL-cholesterol levels and increases in HDL-cholesterol without changes in hemoglobin or albumin levels. The increase in alkaline phosphatase levels is probably caused by the higher lipolisis rate after surgery. The absence of correlations between weight loss or BP levels and LVM reduction suggests that other factors, possibly reductions in body fluid volume may account for LV changes.

GABAergic modulation of noradrenaline release in the median preoptic nucleus area in the rat

Microdialysis was employed to investigate whether γ-aminobutyric acid (GABA) receptor mechanisms are involved in the regulation of noradrenaline (NA) release in the median preoptic nucleus (MnPO) in awake, freely moving rats. Perfusion with the GABA receptor antagonists as well as agonists was performed in the region of the MnPO through a microdialysis probe and dialysate levels of NA were measured. Perfusion with either bicuculline (10 and 50 μM), a GABA A receptor antagonist, or phaclofen (10 and 50 μM), a GABA B receptor antagonist, enhanced the release of NA in the MnPO area. Higher-dose perfusion with the GABA A agonist muscimol (50 μM) or the GABA B agonist baclofen (250 μM) decreased dialysate NA in the MnPO area. An iso-osmotic reduction of fluid volume following subcutaneous treatment with polyethylene glycol (PEG, 30%, 5 ml) significantly increased the NA level in the MnPO area. The increased levels of NA caused by the PEG treatment were attenuated by perfusion with muscimol (10 μM), but not by baclofen (50 μM). These results show the participation of both GABA A and GABA B receptors in the modulation of the release of NA in the MnPO area, and imply that the GABA A receptor mechanism may play an important role in the noradrenergic regulatory system of body fluid balance.

Amnionic infusion therapy in conditions with low amnionic fluid levels

Amniotic fluid volume reduction can have serious consequences: prior to 24 gestational weeks hypoplasia of fetal lungs and later in pregnancy cord compression and fetal hypoxia as well as contractions of extremities. Diagnosis of oligohydramnios is made either after a subjective estimation of amniotic fluid reduction or if the biggest amniotic fluid pocket is less than 1 cm. Amnioinfusion is a procedure during which a crystalloid solution, most often saline, is instilled into the amniotic cavity substituting amniotic fluid. To estimate the efficacy and safety of amnioinsfusion using our results and literature review. Up to 800 ml of sterile saline solution was instilled intraamniotically (10-15 ml/min) in cases where the amniotic fluid index was less than 10 and intraamniotic infection was excluded. After that, 1 g of Longaceph was given intraamniotically. Infusion was stopped immediately when 800 ml was instilled, if a subjective estimation showed that there was enough fluid or if contractions occurred. During a six-month period there were five amnioinfusions--four therapeutical and one diagnostic; in four cases the procedure was successful and in one preterm rupture of membranes occurred 20 hours after the procedure. The procedure was most often done in the first half of the third trimester and continuation of pregnancy in successful cases was between 4 and 5 weeks, with average fetal weight gain of about 1200 gr. No complications occurred in cases where pregnancy continued. In our preliminary study amnioinfusion led to prolongation of pregnancy in majority of cases providing better maturation of fetal lungs and higher birth weight, without any complications. Further studies are necessary to reach definite conclusions about the efficacy and safety of amnioinfusion.

Amniotic fluid and fetal urinary responses to severe placental insufficiency in sheep

Objective: Our purpose was to test the hypothesis that severe placental insufficiency leads to reductions in fetal urine production and amniotic fluid volume in late-gestation fetal sheep. Study Design: At 0.85 of gestation, chronically catheterized fetal sheep with ligated urachus were either embolized for 5 days by repeated injection of boluses of 15-μm microspheres into the common fetal umbilical artery until fetal arterial oxygen content was reduced by 50% (n = 6) or were infused with saline solution (n = 6). Amniotic fluid volume was measured daily before embolization by means of an indicator dilution technique and by drainage at autopsy. Fetal urine production, heart rate, and mean arterial blood pressure were measured continuously for 1 hour before embolization and 1 hour after embolization each day. Fetal arterial blood gases, oxygen content, electrolytes, and osmolality were also monitored. Results: Five days of placental insufficiency, which reduced fetal arterial oxygen content by 50% and arrested fetal growth, resulted in a reduced amniotic fluid volume without a reduction in fetal urine production. Compared with that of controls, amniotic fluid volume was reduced over the 5-day period by 547 ± 144 mL (−62%, P <.01). Amniotic fluid composition was also altered, with a significant increase in lactate and sodium concentrations and osmolality on days 4 to 5. On days 2 to 5, there was a progressive increase in amniotic fluid osmolality above that of controls, which paralleled the changes in amniotic fluid sodium concentration (P <.05). Fetuses became hypertensive on days 2 to 4 of embolization, although this response was attenuated by day 5. Conclusions: Chronic severe placental insufficiency caused a reduction in amniotic fluid volume not attributable to reduced fetal urine production. Changes in amniotic fluid composition induced by placental insufficiency suggest an excess intramembranous absorption of amniotic fluid water, in relation to solutes, into the fetal and maternal compartments, which may lead to the development of oligohydramnios. (Am J Obstet Gynecol 2002;186:1076-84)

Can a reduction in extracellular fluid volume result in increased serum albumin in peritoneal dialysis patients?

Serum albumin predicts survival in end-stage renal failure. The literature has emphasized the dependence of albumin on inflammation. We previously proposed an independent relationship with overhydration. To date, there is no proven therapy that increases serum albumin in dialysis patients. We investigated whether decreasing dry weight increases serum albumin in peritoneal dialysis patients. Twenty-one subjects (15 continuous ambulatory peritoneal dialysis patients and 6 continuous cycled peritoneal dialysis patients) were assessed at 0 and 4 weeks. Body weight, blood pressure, 4-site skin-fold thickness, subjective global assessment score, and use of antihypertensive medication were recorded. Fluid samples were collected for estimation of serum albumin, C-reactive protein, and 24-hour dialysate and urine volume. The extracellular fluid volume was estimated by multiple-frequency bioelectric impedance. Between the 0- and 4-week assessments, dialysis prescription was altered to increase the daily ultrafiltrate volume (1.00 ± 0.71 L to 1.29 ± 0.75 L; P = 0.04). Significant decreases were seen in body weight (70.7 ± 12.1 kg to 69.9 ± 12.2 kg; P = 0.0002), extracellular fluid volume (16.2 ± 3.3 L to 15.5 ± 3.2 L; P = 0.0006), systolic blood pressure (147.7 ± 26.3 mm Hg to 124.2 ± 20.9 mm Hg; P < 0.0001), diastolic blood pressure (84.2 ± 14.5 mm Hg to 76.6 ± 11.7 mm Hg; P = 0.01), and number of antihypertensive drugs (1.9 ± 1.0 to 1.6 ± 1.1; P = 0.02). Serum albumin increased (34.6 ± 4.1 g/L to 35.9 ± 3.6 g/L; P = 0.01). C-reactive protein did not change. Decreasing dry weight in peritoneal dialysis by an increase in ultrafiltration volume results in a decreased extracellular fluid volume, which is reflected by an improvement in blood pressure control. This improvement in blood pressure was associated with an increase in serum albumin. This finding strengthens the argument that overhydration is a cause of hypoalbuminemia in peritoneal dialysis and offers a therapeutic option in management of this patient group. © 2002 by the National Kidney Foundation, Inc.