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Biomedical subjects

E Cruz

Publications and source records attributed to E Cruz.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Inspiratory muscle training in patients with chronic obstructive pulmonary disease].

We analyze the effect of inspiratory muscle training (IMT) in patients with chronic obstructive pulmonary disease (COPD), with special emphasis on its effects on inspiratory muscle function and clinical outcomes. We reviewed only randomized, controlled studies that have either controlled both the load and the breathing pattern when using resistive training or have employed a threshold trainer in which the load is independent of the pattern of breathing, since methodological aspects may explain inconsistent results in the literature. In these circumstances, most of the studies demonstrated positive effects on inspiratory muscle function. Clinical effects were seldom evaluated; limited available data showed a reduction in dyspnea that was related to an increase in maximal inspiratory pressures (PIMax). When exercise capacity was evaluated through the distance the patients were able to walk in 6 or 12 minutes, most studies demonstrated a significant increase. Other reported positive effects were improvement in nocturnal SaO2, inspiratory muscle power output and maximal inspiratory flow rate. Based in this review, a recommended training regime appears to be an intermediate load (30-40% PIMax) using a threshold device for 30 minutes daily for at least 5 weeks. Although in the literature the criteria for selecting patients are not always well defined, we consider IMT as a helpful procedure for pulmonar rehabilitation in those patients with a moderately severe inspiratory muscle dysfunction presenting dyspnea during daily living activities despite optimal therapy.

Anaerobic Threshold↗
PubMed1997

Comparison of the effects of Zopolrestat and Sorbinil on lens myo-inositol influx.

The effects of two structurally dissimilar aldose reductase inhibitors, Zopolrestat and Sorbinil, were investigated on the sodium-dependent, myo-inositol (MI) cotransporter in rat lenses maintained in either normal (5.5 mmol/l) or high sugar medium (35.5 mmol/l glucose or 30 mmol/l galactose). MI influx was compared to the lens polyol content. The effects of Sorbinil (10, 20 and 40 mumol/l) were determined on normal lens MI influx. At all concentrations, Sorbinil had no effect on normal MI influx; therefore, there was no direct effect on the MI transporter. Acute exposure (4-hour incubation) in either high D- or L-glucose media significantly inhibited lens MI influx, which was attributed to competitive inhibition by either D- or L-glucose with MI cotransporter. Due to the short incubation period and rapid metabolism of D-glucose to fructose, there was a low level of polyol (sorbitol) in these lenses. Thus, concomitant administration of Sorbinil (10, 20 and 40 mumol/l) had no significant effect on MI influx in this short-term experiment. Sorbinil had no effect in the presence of L-glucose because L-glucose was not metabolized; thus the polyol content remained normal. To investigate the effects of large accumulations of polyol, lenses were preincubated for 8, 12 and 16 h in 30 mmol/l galactose medium. Large amounts of polyol (galactitol) rapidly accumulated because galactitol was not metabolized. Galactose served as substrate for aldose reductase, and lens polyol (galactitol) content increased markedly. Inhibition of MI influx directly correlated with the increased lens polyol content. Lens polyol accumulation resulted in noncompetitive inhibition of MI influx. Coadministration of 40 mumol/l Sorbinil inhibited 80% of polyol formation and protected 80% of MI influx. Furthermore, in the presence of Sorbinil, lens galactose increased rapidly and equilibrated with galactose in the medium further indicating that Sorbinil inhibited aldose reductase. The effects of 40 mumol/l Sorbinil were compared to 40 mumol/l Zopolrestat. Zopolrestat was as effective as Sorbinil; both aldose reductase inhibitors maintained MI influx at approximately 80% of control values after 12- and 16-hour incubations in high galactose medium. In conclusion, Sorbinil did not exert a direct effect on the sodium-dependent, MI cotransport system or prevent the direct competitive inhibition of either D- or L-glucose. Sorbinil and Zopolrestat inhibited lens polyol formation, thereby eliminating noncompetitive inhibition of MI influx.

Aldehyde Reductase↗
PubMed1997

Effect of pyruvate on lens myo-inositol transport and polyol formation in diabetic cataract.

In diabetic cataract, sorbitol pathway flux perturbs intracellular metabolism by two putative mechanisms. The osmolyte hypothesis implicates the aldose reductase enzyme, increased rate of reduction of glucose of sorbitol and reciprocal osmoregulatory depletion of organic osmolytes (myo-inositol). Redox hypothesis favors alterations in the ratios (NADP+/NADPH and/or NADH/NAD+ as the primary cause of glucose-induced aldose reductase related defects. Increase in NADH/NAD+ promotes increased oxidation of sorbitol to fructose by polyol dehydrogenase; potential normalization of this ratio by coadministration of pyruvate (which reoxidizes NADH to NAD+ via lactate dehydrogenases reaction) was investigated. Effects of exogenous pyruvate on lens polyol formation and sodium-dependent myo-inositol (MI) cotransporter using two in vitro models of sugar cataract were determined. Rat lenses were incubated for 16 h in either normal (5.5 mM) or high sugar medium, 35.5 mM glucose or 30 mM galactose. Then lens MI influx was compared to polyol, MI and fructose content. Pyruvate did not affect MI influx or sorbitol content in lenses incubated in control medium. In 35.5 mM glucose, coadministration of pyruvate maintained lens MI influx at 76% of control values vs. 43% for lenses without pyruvate. Furthermore, pyruvate treatment diminished lens sorbitol content by 50% and increased lens sugar content (myo-inositol, fructose, lactate) and media lactate levels. Lenses incubated in high galactose medium formed galactitol with a corresponding decreased MI content. Coadministration of pyruvate had no effect on either lens sugar content (galactitol, myo-inositol, fructose) or MI influx, consistent with the fact that galactitol was not metabolized to fructose. In conclusion, pyruvate did not exert a direct effect on the MI co-transporter or prevent galactitol inhibition of MI influx. Coadministration of pyruvate with high glucose altered lens metabolism and promoted reduction of pyruvate to lactate, increased fructose, decreased sorbitol, enhanced MI influx, maintained lens MI content, implicating both osmotic and redox systems.

Animals↗
PubMed1997

Inspiratory muscle training in chronic airflow limitation: effect on exercise performance.

The effect of inspiratory muscle training (IMT) on exercise capacity in patients with chronic airflow limitation (CAL) has been debated. The present study was planned to further investigate the effects of IMT on exercise performance. Twenty patients (aged 62+/-1 yrs; forced expiratory volume in one second/forced vital capacity (FEV1/FVC) 36+/-2%) were trained 30 min daily for 6 days a week during 10 weeks, with either 30% (Group 1) or 10% (Group 2) of peak maximal inspiratory pressure (PI,max) as a training load. Exercise performance was evaluated by the distance walked in 6 min (6MWD) and by changes in oxygen consumption (V'O2) and minute ventilation (V'E) during a progressive exercise test. Changes in PI,max and dyspnoea were also measured. Results showed a significant increment in peak PI,max in both groups, whereas dyspnoea and 6MWD improved only in Group 1 (p<0.05 and p<0.01, respectively). No increment in maximal workload or in peak V'O2 was observed in either group. Patients in Group 1, however, showed a reduction in V'E and V'O2 for the same exercise. A correlation between changes in V'E and V'O2 during a workload of 75 kpm x min(-1) was observed in Group 1 (r=0.92; p<0.001). We conclude that inspiratory muscle training using a load of 30% peak maximal inspiratory pressure, improves dyspnoea, increases walking capacity and reduces the metabolic cost of exercise.

Breathing Exercises↗
PubMed1996

Human immunodeficiency virus infection in children with tuberculosis in Santo Domingo, Dominican Republic: prevalence, clinical findings, and response to antituberculosis treatment.

We studied human immunodeficiency virus (HIV)-seroprevalence among children with clinically diagnosed tuberculosis (TB) and compared the clinical features and response to short-term anti-TB therapy of children with and without HIV infection in Santo Domingo, Dominican Republic. Children aged 18-59 months with new-onset, clinically diagnosed TB were tested for HIV antibodies, their clinical features were recorded and their response to a standard 6-month regimen of daily isoniazid and rifampicin with daily streptomycin and pyrazinamide for the first 2 months was assessed. To increase the number of HIV-infected children with TB available for study, we also included children previously known to be HIV infected who developed new-onset TB. Eleven (5.8%) of 189 consecutively enrolled children with clinically diagnosed TB were HIV infected. Fifteen other children with previously documented HIV infection and new-onset TB were available for study, yielding 26 HIV-positive and 178 HIV-negative children with TB. Of these 204 children with clinically diagnosed TB, 25 HIV-positive and 156 HIV-negative children were successfully followed for 6 months or until death. The proportion of HIV-positive children who failed treatment was 6 (29%) of 21 as compared with only 5 (3%) of 156 HIV-negative children [relative risk = 8.9; 95% confidence interval (CI) 2.9, 26.6; p = 0.0004]. HIV-infected children with clinically diagnosed TB are substantially more likely to fail standard treatment for TB than are HIV-uninfected children. If standard treatment regimens are used in such children, response to treatment must be monitored very closely and appropriate changes in the regimen must be made expeditiously.

AIDS Serodiagnosis↗
PubMed1996

Zopolrestat prevention of proteinuria, albuminuria and cataractogenesis in diabetes mellitus.

The aldose reductase inhibitor, Zopolrestat, reduced proteinuria and albuminuria in streptozocin-induced diabetic rats compared with both untreated diabetic and age-matched controls. Daily administration of Zopolrestat (100 mg/kg) for 4 months decreased 24 h total protein excretion to 15.07 +/- 2.17 mg from 49.97 +/- 7.94 mg/day in untreated diabetic rats. Zopolrestat protected against excretion of any array of urinary proteins with molecular weights between 30 and 100 kD. These effects were sustained throughout the 5th and 6th months of treatment. At the end of 6 months, Zopolrestat-treated diabetic rats excreted 22.77 +/- 4.39 mg/day compared to untreated diabetic rats (67.05 +/- 14.03 mg/day), a 6-fold increase in urinary protein excretion compared to age-matched nondiabetic controls (11.65 +/- 1.71 mg/day). Zopolrestat treatment for 6 months produced therapeutic effects in the lens: transparency and myo-inositol content were maintained and lens sorbitol diminished, despite elevated lens glucose. In contrast, untreated diabetic rats had opaque lenses which exhibited a 40-fold increase in sorbitol and myo-inositol depletion. In opaque lenses, ouabain-sensitive Rb influx, an index of Na-K-ATPase activity, decreased to only 53.8% of mean values in age-matched controls; the ouabain-insensitive component increased by 63.6%. Zopolrestat treatment prevented these diabetic-induced changes and maintained ouabain-sensitive and ouabain-insensitive Rb influx. Collectively, these results suggest that Zopolrestat exerts a protective effect on the slowly developing diabetic cataract, as well as reducing albuminuria and proteinuria.

Albuminuria↗
PubMed1996

Effects of azathioprine withdrawal in kidney recipients with stable function two years after transplant.

To assess the effects of azathioprine withdrawal, renal recipients with grafts > 2 yr function (103 study patients) were tapered off azathioprine over a 1-yr period and compared to 69 patients 2 yr after transplant who were not tapered (controls). Of the 103 study patients, 16 (15%) were living-donor transplants and 87 were cadaveric. Of the 69 control patients, 9 (13%) were living related transplants and 60 were cadaveric. The mean HLA match for those tapered was 3.3 Ag and 3.1 Ag for those remaining on azathioprine. Two study patients restarted azathioprine on their own. Age, sex, and cause of renal failure in both groups was similar. Of the 101 study patients remaining, 9 (8.8%) returned to dialysis due to biopsy proven chronic rejection. There were no acute rejection episodes. Six of the 69 control patients (8.7%) also returned to dialysis for the same reason. Of the 92 patients who have completed the taper, 85 have been off azathioprine for six or more months. There was not a significant difference between the mean 12- and 24-month creatinine levels of the study patients (1.6 mg%, 1.7 mg%) and those of the controls (1.5 mg%, 1.8 mg%). The mean 12- and 24-month hematocritis of patients tapered (41.3%, 40.8%) were comparable with patients not tapered (42.3%, 42.8%). Of interest, the mean hematocritis of both study and control patients rose from 28.9% and 33.5%, respectively, to 41.3% and 42.3% 1 yr following entry into the study. The mean 12- and 24-month white blood counts of those tapered (8.9, 8.7) did not differ significantly from those continued on azathioprine (8.8, 8.8). In stable renal transplant patients on triple drug immunosuppression for at least 2 yr, azathioprine can be discontinued, in a tapered protocol, without an increased risk of graft loss or compromise of renal function.

Azathioprine↗
PubMed1995

Measurement of pleural fluid cholesterol and lactate dehydrogenase. A simple and accurate set of indicators for separating exudates from transudates.

OBJECTIVES: To evaluate the usefulness of diverse combinations of pleural cholesterol concentration, pleural or serum protein, and lactate dehydrogenase (LDH) levels for the differentiation of pleural exudates and transudates. DESIGN: Prospective laboratory study of pleural effusions. SETTING: Medical school hospital. PATIENTS: One hundred eighty consecutive internal medicine ward patients in whom the etiologic diagnosis of their pleural effusion was confirmed. MEASUREMENTS: Cholesterol concentration in pleural fluid and protein and LDH both in pleural fluid and blood serum. RESULTS: According to their etiology, 49 (27.2%) of the effusions were transudates and 131 (72.7%) were exudates. Using a cutoff point of 45 mg for pleural cholesterol and values for protein and LDH of Light et al, the best diagnostic power corresponded to the combination of pleural cholesterol and LDH: cholesterol level over 45 mg/dL and/or LDH over 200 IU/L identified exudates with a sensitivity of 99% and a specificity of 98%. All the other combinations showed inferior values and the criteria of Light et al reached 98 and 82%, respectively. CONCLUSIONS: The measurement of pleural cholesterol and LDH permits the separation of pleural exudates from transudates with an accuracy similar to the original report of Light et al, with the advantage of requiring only two laboratory determinations and no simultaneous blood sample.

Cholesterol↗
PubMed1994

Sclerocornea, hypertelorism, syndactyly, and ambiguous genitalia.

We present a child with an MCA pattern of sclerocornea, hypertelorism, pterygium colli, upper limb syndactyly, ambiguous genitalia, abnormal ears and nose, umbilical hernia, congenital heart disease, and normal chromosomes (46,XX). Although the defects observed in this case follow the diagnostic criteria for Fraser syndrome proposed by Thomas et al. [1986: Am J Med Genet 25:85-98], we think that this is a different entity.

Abnormalities, Multiple↗
PubMed1994

Inspiratory muscle training in chronic airflow limitation: comparison of two different training loads with a threshold device.

The usefulness of inspiratory muscle training (IMT) in chronic airflow limitation (CAL) patients is a controversial issue, mainly due to differences in the training load. To further evaluate this aspect, we studied the effect of the magnitude of the load using a threshold pressure trainer. Ten CAL patients (5 males, 5 females) 67 +/- 2 yrs (mean +/- SEM) and forced expiratory volume in one second (FEV1) 36 +/- 2% pred, were trained for 30 min a day using a load of 30% of their maximal inspiratory mouth pressure (PImax) (Group 1). Another 10 CAL patients (5 males, 5 females), 73 +/- 2 yrs and FEV1 37 +/- 2% pred), were trained using only 12% of their PImax (Group 2). Training was assessed by PImax, inspiratory muscle power output (IMPO), sustainable inspiratory pressure (SIP), maximal inspiratory flow rate (VImax), pattern of breathing during loaded breathing, Mahler's dyspnoea score, and the 6 min walking distance (6MWD). After 5 weeks of training, Group 1 exhibited significant increments in: PImax (34 +/- 11%); IMPO (92 +/- 16%); SIP (36 +/- 9%); and VImax (34 +/- 13%). Dyspnoea was also reduced, and the 6MWD increased by 48 +/- 22 m. We observed no significant changes in Group 2. During loaded breathing, Group 1 showed a significant increment in tidal volume (VT) and mean inspiratory flow (VT/TI), and a reduction in inspiratory time (TI). In Group 2, VT and VT/TI also increased significantly, but the breathing frequency increased with a reduction of expiratory time.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Tetrahydroaminoacridine affects the cholinergic function of blood-brain barrier.

In rat brain microvessels, tetrahydroaminoacridine (THA) caused a significant inhibition of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities, in a dose-dependent manner. THA resulted to be a more potent inhibitor of BuChE than AChE. Lineweaver-Burk plots showed that Km (app) and V were altered by THA, indicating mixed competitive/non-competitive inhibition. The results of the present study also established that the three molecular forms of BuChE (G1, G2 and G4), recently described to be present in brain microvessels, are inhibited after THA treatment.

Acetylcholinesterase↗
PubMed1993

[Treatment of acute lymphoid leukemia (ALL) in the child].

PURPOSE: To analyse the results of the therapy administered to children with ALL in Cuba. PATIENTS AND METHODS: Four-hundred and twenty-five children (aged below 15 years), diagnosed of ALL in 8 different Cuban hospitals between 1973 and 1991, were evaluated. Five different therapeutic regimes were used: three "classic" GLATHEM protocols in the first period (1973-1981) and two intensive BFM-like protocols in the second period (1982-1991). The Kaplan-Meier method was applied for survival analysis, and the differences were evaluated by the log-rank and Mantel-Cox methods. RESULTS: Two-hundred and sixty-five patients were included in the first period, 81 with low-risk disease, 133 with standard risk and 51 with poor-risk leukaemia. The second period comprised 160 cases, 50 of low-risk, 83 with standard risk and 27 with poor-risk leukaemia. The disease-free survival probability at 60 months was 35% for the first group and 55% for the second (p < 0.0001). The 60-month survival (SV) as a whole was 45% for the "classic" treatments and 60% for the BFM-like protocols (p < 0.01). The disease-free survival (DFS) probability for each prognostic group was as follows: 50% for low-risk, 43% for standard risk, and 25% for poor-risk (p < 0.001) and the probability of survival as a whole was, respectively, 65%, 49% and 28% (p < 0.001). as for this compilation, 172 patients were out of any treatment for periods ranging between 14 and 168 months. CONCLUSIONS: 1) The percentage of remissions was similar for both groups of treatments. 2) The results attained with BFM-like protocols were better than those of the "classic" therapy with regard to the SV and DFS differences. 3) Significant differences can be appreciated between good- and poor-prognosis groups for both types of treatment.

Adolescent↗
PubMed1992

HIV-1 infection among non-intravenous drug user female prostitutes in Spain. No evidence of evolution to pattern II.

OBJECTIVES: To assess the prevalence of HIV-1 infection among non-intravenous drug user (IVDU) female prostitutes in Spain and to determine risk factors for HIV-1 infection in this population. DESIGN: Cross-sectional seroepidemiological study of 519 non-IVDU prostitutes. SETTING: Four university hospitals. METHODS: All participants completed a questionnaire and provided a serum sample. Serum samples were tested for antibodies against HIV-1, hepatitis C virus (HCV) and Treponema pallidum. RESULTS: Twelve out of the 519 (2.31%) participants were HIV-1-seropositive. HIV-1 infection was associated with the presence of both HCV and T. pallidum antibodies, multiple sex partners, longer history of prostitution, history of genital ulcers and anal intercourse. Condom use was associated with HIV-1 seronegativity. CONCLUSIONS: The prevalence of HIV-1 infection in non-IVDU prostitutes in Spain remains relatively low. Risk increases with a higher rate of sexual exposure and practices such as anal intercourse and unprotected coitus.

Adolescent↗
PubMed1992

Comparison of sorbinil and ponalrestat (Statil) diminution of proteinuria in the BB rat.

Diabetic nephropathy leading to kidney failure is a major complication of type I (insulin-dependent) diabetes mellitus and is associated with progressive proteinuria. In the present 6-month study, effects of two structurally dissimilar aldose reductase inhibitors (sorbinil and ponalrestat or Statil) were examined on prevention of proteinuria in insulin-dependent spontaneously diabetic BB rats and compared with age-matched BB resistant controls. Prior to aldose reductase inhibitor treatment, all diabetic BB rats exhibited hyperglycemia (> 300 mg/dl), glycosuria (> 2,000 mg/dl) and 24-hour urinary protein excretion ranging from 5.01 to 11.23 mg/day. After daily administration of ponalrestat (20 mg/kg) for 3 months, 24-hour urinary protein excretion was 11.53 +/- 1.76 mg/day in ponalrestat-treated rats, despite persistence of hyperglycemia (444 +/- 31 mg/dl) and glycosuria (> 2,000 mg/dl); by contrast, urinary protein excretion was 17.76 +/- 2.59 mg/day in the control group of untreated BB diabetic rats. Ponalrestat initially protected against excretion of an array of urinary proteins having molecular weights between 30,000 and 100,000 daltons. These effects sustained throughout the 4th month of treatment, tended to change toward valves in control rats by the 5th month. At the end of 6 months, ponalrestat-treated diabetic rats excreted 18.73 +/- 3.20 mg/day of protein, similar to valves in untreated BB diabetic rats; both demonstrated a 4-fold increase in urinary protein excretion when compared to age-matched BB resistant controls. Proteinuria was attributed to an increase in albumin and an array of proteins having molecular weights between 30,000 and 100,000 daltons.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

Myo-inositol transport in the lens of galactose-maintained rats.

Lens myo-inositol (MI) content is regulated by a pump-leak system consisting of an active Na-dependent MI transport and its passive permeability through the membrane. We measured the active MI uptake and membrane permeability in lenses of rats maintained on a 50% galactose diet for 1, 3 and 7 days. After only 1 day of galactose feeding, active MI uptake in the lens was reduced dramatically by 74% compared to age-matched control lenses; by day 3, active MI transport was decreased by 89% and it was undetectable by day 7. The passive membrane permeability was determined by measuring (a) the passive MI influx and (b) the 3H-sorbitol flux. After 1 day of galactose feeding, the membrane permeability increased such that within 3 days it increased to 5-6 fold. Galactose feeding also led to a rapid increase in lens polyol content. After 1 day, lens polyol increased to 53 mumol/g wet wt compared to a control value of 0.35 mumol/g wet wt and increased further to 65 and 72 mumol/g wet wt after 3 and 7 days of galactose feeding respectively. Lens galactose accumulation was low (3 mumol/g wet wt) up to 7 days; however, it was rapidly increased after 7 days. Our results indicate that galactose feeding rapidly interfered with MI homeostasis by a severe depression of active MI transport and a rapid increase in membrane permeability. These interferences of MI homeostasis correlate with the appearance of high polyol levels.

Animals↗
PubMed1992

[Intermittent negative pressure ventilation in patients with chronic air flow limitation: criteria for selection of patients].

To determine clinical and functional predictive criteria for use of intermittent negative pressure ventilation we evaluated 9 patients with severe chronic air flow limitation. Arterial blood gases, lung volumes, maximal inspiratory pressures and transdiaphragmatic pressure during quiet breathing were measured. patients were then ventilated once or twice a week for 3 to 10 weeks and improvement was evaluated through changes in quality of life, dyspnea, PaO2, PaCO2 and maximal inspiratory mouth pressure (PRMAX). Result was considered good when 4 or more of these indices improved. 5 patients benefitted from intermittent negative pressure ventilation. Compared to non responders, patients who improved had significantly lower PRMAX (39.4 +/- 11.6 VS 73.5 +/- 13.8 CMh20, p < 0.025), and higher percentage of their maximal inspiratory pressure during quiet breathing (31.2 +/- 7 vs 12.2 +/- 5%, p < 0.025>). Other indices were not different between groups. We conclude that a severe impairment of inspiratory muscle function characterizes patients with chronic air flow limitation who may benefit from intermittent negative pressure ventilation.

Adult↗
PubMed1991

Ventilatory drive and respiratory muscle function in pregnancy.

It has been demonstrated that during pregnancy expiratory reserve volume (ERV) decreases and minute ventilation (VE) increases initially and then stabilizes. In order to determine the role of thoracoabdominal mechanics, control of breathing, and inspiratory muscle function in these alterations, we studied inspiratory pressures, lung volumes, thoracic configuration, and respiratory drive in 18 normal pregnant women at Weeks 13, 21, 30, and 37 of pregnancy. Ten of them were studied 6 months after delivery. Transdiaphragmatic pressure (Pdi) was measured at Week 37 and 3 months after delivery in an additional group of seven women. VE as well as VT/TI increased early during gestation and remained unchanged thereafter. In contrast, mouth occlusion pressure (P0.1) increased progressively during pregnancy, from 1.53 +/- 0.16 (mean +/- SE) to 2.02 +/- 0.18 cm H2O, and fell significantly to 1.1 +/- 0.15 cm H2O after delivery, indicating that effective respiratory impedance increases during pregnancy. Mean P0.1 correlated with progesterone plasma levels (r = 0.918 p less than 0.05). No changes in Plmax, PEmax, and Pdimax, were observed. End-expiratory gastric pressure (Pga) increases significantly during pregnancy: 11.8 +/- 0.8 versus 8.4 +/- 1.12 cm H2O after delivery (p less than 0.012). This increment was correlated with the fall in ERV observed in late pregnancy (r = 0.74 p less than 0.05). Our results demonstrate that during pregnancy ventilatory drive and respiratory impedance increase with the consequent stabilization of VE, but our data do not permit us to differentiate whether the increment in P0.1 is secondary to the increase in impedance or to the rise in progesterone. Respiratory muscle function remains normal despite the alteration of thoracic configuration.

Adult↗