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We studied the respiratory output in five subjects exposed to parabolic flights [gravity vector 1, 1.8 and 0 gravity vector in the craniocaudal direction (Gz)] and when switching from sitting to supine (legs bent at the knees). Despite differences in total respiratory compliance (highest at 0 Gz and in supine and minimum at 1.8 Gz), no significant changes in elastic inspiratory work were observed in the various conditions, except when comparing 1.8 Gz with 1 Gz (subjects were in the seated position in all circumstances), although the elastic work had an inverse relationship with total respiratory compliance that was highest at 0 Gz and in supine posture and minimum at 1.8 Gz. Relative to 1 Gz, lung resistance (airways plus lung tissue) increased significantly by 52% in the supine but slightly decreased at 0 Gz. We calculated, for each condition, the tidal volume changes based on the energy available in the preceding phase and concluded that an increase in inspiratory muscle output occurs when respiratory load increases (e.g., going from 0 to 1.8 Gz), whereas a decrease occurs in the opposite case (e.g., from 1.8 to 0 Gz). Despite these immediate changes, ventilation increased, going to 1.8 and 0 Gz (up to ≈23%), reflecting an increase in mean inspiratory flow rate, tidal volume, and respiratory frequency, while ventilation decreased (approximately -14%), shifting to supine posture (transition time ∼15 s). These data suggest a remarkable feature in the mechanical arrangement of the respiratory system such that it can maintain the ventilatory output with small changes in inspiratory muscle work in face of considerable changes in configuration and mechanical properties. [ABSTRACT FROM AUTHOR]

High-frequency ventilation was investigated in a model of the central airways of a human lung cast enclosed in a spherical cavity (alveolí). The experiments were performed at high frequencies (5, 10, 15 and 20 Hz) and tidal volumes (50, 90 and 120 cm) less than the anatomical dead space volume. The efficiency of gas mixing in the model was assessed by measuring the decay of carbon dioxide concentration in the sphere during high-frequency mechanical ventilation. The experimental results were then compared with those obtained from simulations on a theoretical model based on a diffusional resistance concept which could take account of either turbulent, steady laminar or oscillatory laminar dispersion coefficients. Our results showed that the Taylor turbulent dispersion mechanism had a significant effect and could be the principal factor for the efficiency of gas mixing during high-frequency ventilation at small tidal volumes. [ABSTRACT FROM AUTHOR]

Introduction: Ischemic Priapism is defined as an abnormally prolonged state of erection, exceeding 6 h, often and irreducible, occurring without any sexual stimulation. Ischemic priapism has a fatal consequence on the sexual function of men if it's not promptly managed. This pathology can cause erectile dysfunction and this can alter the quality of life of patients., Objective: The aim of our study was to determine the factors influencing erectile function after treatment of ischemic priapism., Patients and Methods: This is a ten-year retrospective, descriptive and analytic study of 40 patients who consulted the urology department at the university hospital center for treatment of ischemic priapism (2010-2019)., Results: We included 40 patients in our study. The mean age was 35.2 [18-62]. Duration of priapism varied from 20 to 360 h (mean 76.6). The most common etiology of priapism was sickle cell disease in 65% of cases. The mean preoperative IIEF-5 score was 23 [21-26]. All patients underwent corporal aspiration with an injection of ephedrine, but detumescence was observed in only 10% of cases. Thirty-six patients had a distal shunt with detumescence in approximately 70% of cases. Eleven patients underwent a distal shunt but seven patients had definitive fibrosis. After the episode of priapism, only eight patients retained normal erectile function. The mean postoperative IIEF-5 score was 14 [ 7-26]. We noted an improvement in erectile function in 8 patients treated with tadalafil. In multivariate analysis, we have demonstrated that a treatment delay exceeding 48 h, fibrosis and the necessity of a distal shunt significantly affects postoperative erectile function (p = 0.001; p = 0.002; p = 0.002 respectively)., Conclusion: According to our study, delayed management exceeding 48 h, fibrosis and the necessity of a surgical distal shunt are three independent factors affecting erectile function after treatment of ischemic priapism., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

Membrane conductance (Dm) and capillary lung volume (Vc) derived from NO and CO lung transfer measurements in humans depend on the blood conductance (θ) values of both gases. Many θ values have been proposed in the literature. In the present study, measurements of CO and NO transfer while breathing 15% or 21% O2 allowed the estimation of θNO and the calculation of the optimal equation relating 1/θCO to pulmonary capillary oxygen pressure (PcapO2). In 10 healthy subjects, the mean calculated θNO value was similar to the θNO value previously reported in the literature (4.5mmHgmin(-1)) provided that one among three θCO equations from the literature was chosen. Setting 1/θCO=a·PcapO2+b, optimal values of a and b could be chosen using two methods: 1) by minimizing the difference between Dm/Vc ratios for any PcapO2, 2) by establishing a linear equation relating a and b. Using these methods, we are proposing the equation 1/θCO=0.0062·PcapO2+1.16, which is similar to two equations previously reported in the literature. With this set of θ values, DmCO reached the morphometric range., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objectives: To examine the outcomes of 2 commonly performed urologic office procedures as a part of a process to align these with the Joint Commission standards to ensure patient safety. We determined whether cystoscopy and transrectal ultrasound-guided prostate biopsy performed in the office setting pose minimal risk to patients., Methods: An evaluation of urologic office procedures in the office clinic setting of an academic medical center was prospectively performed during 3 different periods to document patient and system events. The patients included those undergoing cystoscopy for workup of hematuria, history of bladder cancer, or other indicated conditions (n = 554) and patients undergoing transrectal ultrasound-guided prostate biopsy for suspicion of prostate cancer (n = 367). All consecutive patients were evaluated., Results: A total of 7 patient events (0.76%) and 101 system events (10.97%) were documented. The most significant adverse patient event was 1 case of acute bacterial prostatitis due to quinolone-resistant Escherichia coli. In most cases, the system event rate reflected a delay of >15 minutes in the initiation of the procedure. No patient experienced significant bleeding, perforation, or a major cardiopulmonary event., Conclusions: The results of our study have shown that cystoscopy and transrectal ultrasound-guided prostate biopsy procedures performed in the office setting pose a minimal risk to patients. This information could be useful for hospitals and practices that are undergoing efforts to align their individual policies with current Joint Commission standards.

Objective: This work was carried out to study induction with sevoflurane in adult patients with predictive signs of difficult intubation., Study Design: Randomised prospective study., Patients and Methods: The study had two parts. Part I: 15 patients without predictive signs of difficult intubation but with a cervical collar. Eight patients were anaesthetised with propofol 3 mg.kg-1 and fentanyl 2 micrograms.kg-1, seven with sevoflurane 8%. Part II: 20 patients with predictive signs of difficult intubation anaesthetised with sevoflurane 8%., Results: In part I, all patients were intubated, the time for intubation was longer with sevoflurane, 6 vs 4 min. They were apneic only in the propofol group. After intubation, 7 cases of coughing (4 severe) occurred in the propofol group and 3 moderate coughing in the sevoflurane group. In part II, one patient experienced considerable agitation after oral airway insertion and was excluded. Other patients were intubated with sevoflurane. Seven patients were intubated with a bougie, three patients through an intubating LMA and one patient with a rigid bronchoscope. The other patients were intubated with a Macintosh blade. The mean time for intubation was 10 +/- 7 min and end tidal sevoflurane concentration after intubation was 4 +/- 0.6%. After intubation, 7 cases of coughing (3 severe) occurred but no desaturation < 95%. No significant haemodynamic variations occurred., Conclusion: Induction with sevoflurane 8% allowed tracheal intubation without major incidents. All patients breathed spontaneously. Sevoflurane can be recommended for induction in cases of predictive difficult intubation.

Variations in gravity [head-to-foot acceleration (Gz)] induce hemodynamic alterations as a consequence of changes in hydrostatic pressure gradients. To estimate the contribution of the lower limbs to blood pooling or shifting during the different gravity phases of a parabolic flight, we measured instantaneous thigh and calf girths by using strain-gauge plethysmography in five healthy volunteers. From these circumferential measurements, segmental leg volumes were calculated at 1, 1.7, and 0 Gz. During hypergravity, leg segment volumes increased by 0.9% for the thigh (P < 0.001) and 0.5% for the calf (P < 0.001) relative to 1-Gz conditions. After sudden exposure to microgravity following hypergravity, leg segment volumes were reduced by 3.5% for the thigh (P < 0.001) and 2.5% for the calf (P < 0.001) relative to 1.7-Gz conditions. Changes were more pronounced at the upper part of the leg. Extrapolation to the whole lower limb yielded an estimated 60-ml increase in leg volume at the end of the hypergravity phase and a subsequent 225-ml decrease during microgravity. Although quantitatively less than previous estimations, these blood shifts may participate in the hemodynamic alterations observed during hypergravity and weightlessness.

Data from the Spacelab Life Sciences-1 (SLS-1) mission have shown sustained but moderate increase in pulmonary diffusing capacity (DL). Because of the occupational constraints of the mission, data were only obtained after 24 h of exposure to microgravity. Parabolic flights are often used to study some effects of microgravity, and we measured changes in DL occurring at the very onset of weightlessness. Measurements of DL, membrane diffusing capacity, and pulmonary capillary blood volume were made in 10 male subjects during the 20-s 0-G phases of parabolic flights performed by the "zero-G" Caravelle aircraft. Using the standardized single-breath technique, we measured DL for CO and nitric oxide simultaneously. We found significant increases in DL for CO (62%), in membrane diffusing capacity for CO (47%), in DL for nitric oxide (47%), and in pulmonary capillary blood volume (71%). We conclude that major changes in the alveolar membrane gas transfers and in the pulmonary capillary bed occur at the very onset of microgravity. Because these changes are much greater than those reported during sustained microgravity, the effects of rapid transition from hypergravity to microgravity during parabolic flights remain questionable.

The goal of regeneration in oral maxillofacial reconstruction is replacing the previous goal of repair. Many advances in treatment and diagnosis have taken place in medicine and dentistry with the advent of DNA technology. The purpose of this paper is to provide the dental practitioner an overview of some of the medical research using recombinant DNA technology and its potential use in dentistry.

A successful laparoendoscopic excision of a 3-cm leiomyoma of the stomach is reported. Review of related literature and suggested technique and methods for this procedure are described.

The electromyograms of the rectus abdominis (EMGra) and of the diaphragm (EMGdi) have been recorded on human subjects immersed at two bath temperatures (TW), 25 and 40 degrees C. The recordings were obtained during a calibrated isometric contraction sustained for 20 s against a closed stopcock at functional residual capacity (FRC) level for EMGra (expiratory effort) and at pulmonary volume greater than 90% vital capacity for EMGdi and EMGra (inspiratory effort). After eliminating the electrocardiographic artifact, the EMG signal was processed to obtain its root-mean-square (rms) value and three parameters of its frequency spectrum, total energy (Etot), centroid frequency (fc), and high-to-low ratio (H/L). The results show that EMGdi is not modified by TW. On the other hand rms and Etot of EMGra are always increased at TW = 25 degrees C compared with TW = 40 degrees C, whereas fc and H/L decrease with temperature during the expiratory effort at FRC level but do not vary during inspiratory effort at high pulmonary volume. These results, compared with those previously published for cooled limb muscles, show that TW can elicit EMG alterations on the superficial respiratory muscles through two mechanisms, an intrinsic mechanism due to the local variation in muscle temperature and an extrinsic mechanism acting upon the control system of the muscle contraction. Linked alterations of the muscular mechanical activity probably account for the observed effects of TW on the statics and the dynamics of the pulmonary volumes.

A new graphic representation of respiratory heat exchange is proposed using the concept of equivalent temperatures directly related to enthalpy values. On such a diagram it is possible to 1) compute the value of the heat exchange (delta H) knowing the inspired temperature (TI) and the partial pressure of water vapor (PIH2O) [or the relative humidity (rhI)] of inspired gas; 2) estimate the variation in delta H following a given variation in TI and PIH2O or, inversely, to choose the variation in TI and PIH2O necessary to obtain a given variation in delta H; 3) dissociate inspiratory and expiratory exchanges and to evaluate the efficiency of the respiratory heat exchange process in different environmental situations; and 4) easily compare the results of different studies published on respiratory heat exchanges in humans or other animal species.

A method allowing the measurement of mean alveolar pressure (Palv) during forced vital capacity is described. The basis of the method is the calculation of the difference between mouth and chest flows, which are measured with a Fleisch pneumotachograph (PTG) and a volumetric plethysmograph respectively. Metrologic conditions of the calculation are discussed. During the forced expiration, the estimation of Palv is realized in good metrological conditions. During inspiration, the thermal condition of the PTG varies and the measured flow is not accurate; thus, the calculated Palv is only an estimation. Some examples of Palv vs mouth flow loops are shown. The simultaneous recordings of this loop and the usual V/V loop allow us to know if a low mouth flow is due to a high pulmonary impedance with high Palv or to a low Palv. For a given impedance, Palv measurement seems to be a good test of the respiratory muscle function.

In order to throw more light on the mechanisms governing the efficiency of intrapulmonary gas mixing during high-frequency oscillatory ventilation, an experimental, and theoretical, study was carried out on a model casting of the airways of a human lung that closely resembled the respiratory tract. The experiments were carried out under various conditions during high-frequency oscillation (HFO), by using alveolor resident gas mixtures of different densities. The efficiency of gas mixing was assessed by measuring the time constants of the CO2 alveolar washout which were compared to those obtained from simulations on a theoretical model based on a turbulent diffusional resistance concept. Our results showed that the decay in CO2 concentration was highly dependent on both frequency (f) and tidal volume (VT). Tidal volume was found to have a greater effect on efficiency of gas mixing than frequency. Moreover, even though there were statistically significant differences in the time courses of CO2 washout between N2 and He, N2 and SF6 or between He and SF6, this could not imply that gas mixing was limited by diffusion. Agreement between the experimental time constants of CO2 elimination during HFO and the predicted mixing time constants was satisfactory. It is concluded that turbulent augmented diffusion is the main factor responsible for effective gas transport during high-frequency oscillatory ventilation.

Pulmonary volumes and capacities have been measured at three water temperatures (Tw = 25, 34, 40 degrees C) in standing subjects immersed up to the shoulders. The comparison of data obtained in air with those obtained in thermoneutral immersion (Tw = 34 degrees C) confirms the results previously published in several studies. The comparison of data obtained in immersion at different Tw shows: 1. A significant decrease in vital capacity (VC) with bath temperature (VC 40 degrees C greater than VC 34 degrees C greater than VC 25 degrees C). The same decrease is observed in the inspiratory reserve volume (IRV) while the expiratory reserve volume (ERV), the residual volume (RV) and the functional residual capacity (FRC) do not vary. 2. A significant decrease in maximum breathing capacity (MBC) with bath temperature (MBC 40 degrees C greater than MBC 25 degrees C). 3. A significant increase in tidal volume (VT) in cold or hot water compared to thermoneutral water (VT40 degrees C greater than VT34 degrees C; VT34 degrees C less than VT25 degrees C) during quiet breathing. Breathing frequency does not change, thus ventilation (V) follows the same evolution as VT. The relative abdominal (ABD) contribution to VT, estimated by a double belt inductance plethysmograph, is reduced at Tw = 25 degrees C but unchanged at Tw = 40 degrees C compared to thermoneutral bath. Beside variations in the metabolic state, the variations of the pulmonary volumes as a function of Tw are estimated to be mainly due to alterations in respiratory muscles functioning.