Comparison of body fluid distribution between chronic haemodialysis and peritoneal dialysis patients as assessed by biophysical and biochemical methods.

BACKGROUND: The control of extracellular volume is a key parameter for reducing hypertension and the incidence of cardiovascular mortality in dialysis patients. In recent years bioimpedance measurement (BIA) has been proven as a non-invasive and accurate method for measuring intracellular and extracellular fluid spaces in man. In addition, plasma atrial natriuretic peptide (ANP) and cyclic guanosine monophosphatase (cGMP) concentrations have been shown to reflect central venous filling. Using these methods, we compared body fluid status between stable patients on haemodialysis and peritoneal dialysis. METHODS: Thirty-nine chronic haemodialysis patients, 43 chronic peritoneal dialysis patients and 22 healthy controls were included in the study. Multifrequency BIA was performed using the Xitron BIS4000B device (frequencies from 5 to 500 kHz were scanned and fitted) in patients before and after haemodialysis. Peritoneal dialysis patients were measured after drainage of the dialysate. Plasma ANP and cGMP levels were measured in plasma using a (125)I solid phase RIA. Serum albumin concentrations and serum osmolality were measured in all patients. The body fluid data were analysed in relation with the clinical findings. RESULTS: Total body water (TBW) was 0.471+/-0.066 l/kg before haemodialysis and 0.466+/-0.054 l/kg after haemodialysis. Peritoneal dialysis patients had a TBW (0.498+/-0.063 l/kg) that was greater than the before and after dialysis values of haemodialysis patients. The extracellular body fluid (V(ecf)) was increased pre-haemodialysis. It was even greater in peritoneal dialysis patients compared with patients both pre- and post-haemodialysis (pre 0.276+/-0.037 l/kg; post 0.254+/-0.034 l/kg; peritoneal dialysis 0.293+/-0.042 l/kg, P<0.05). However, plasma ANP concentrations (representing intravascular filling) in peritoneal dialysis patients were comparable with post-haemodialysis values (284+/-191 pg/ml vs 286+/-144 pg/ml). The correlation coefficient between sysRR and V(ecf) was r=0.257 in haemodialysis (P=0.057) and r=0.258 in peritoneal dialysis (P<0.05). A significant negative correlation was found between serum albumin and V(ecf)/TBW in peritoneal dialysis patients (r= -0.624). CONCLUSION: Body fluid analysis by BIA demonstrated that TBW and V(ecf) were increased in peritoneal dialysis patients, and were comparable or even greater than values found before haemodialysis. However, plasma ANP levels indicated that intravascular filling was not increased in peritoneal dialysis. The ratio of V(ecf) to TBW was correlated to systolic pressure and negatively to serum albumin in peritoneal dialysis patients.     

The trigeminocardiac reflex: Does the activation pathway of its efferent arc affect the intensity of the hemodynamic drop during the management of maxillofacial fractures?

The study aimed to correlate between the stimulated nerve, intensity of trigeminovagal reflex (TVR), and neuropathophysiological pathway by which the efferent arc is activated. Material and methods: A retrospective study included patients who developed TVR during the surgical management of mandibular, midface, and orbital fractures. The reflex was divided into type I, II, III, and IV-TVR according to the following nerves: ophthalmic, maxillary, mandibular, and non-trigeminal nerves, respectively. The magnitude of hemodynamic drops was identified at the intraoperative baseline, during reflex, and postoperatively. The needed time to elicit the reflex, frequency and duration, need for medical intervention, and sequence of the drop were also recorded. P - values < 0.05 was considered significant.Out of 260 patients’ files were reviewed, the TVR was observed in only 30 (11.55 %) patients. The ophthalmic nerve activation significantly caused the greatest intensity and magnitude of hemodynamic drop, followed by maxillary nerve, then mandibular division, and the lowest one was non-trigeminal nerves. The highest mean of drops in the mean arterial blood pressure (MABP) was 62.92 ± 2.39 with the type ITVR, whereas those of the type II, III, and IV were 75.5 ±3.98, 81.02±1.31, and 82.22±1.85, respectively. Also, the type I-TVR led to the greatest decrease in the heart rate (HR) with the mean equaled to 52.31± 3.91. The drop percentage in the MABP was -30.5, -17.5, -12, -10.08 for type I, II, III, and IV, whereas those of the HR were - 33.9, -27.13, -26.6, and -25 with type I, II, III, and IV, respectively. All results showed highly significant differences with p-values less than 0.001 when comparing between the baseline and intraoperative values of each TVR type.There is a positive correlation between the activated pathway of the TVR and the intensity of its efferent arc response due to the neural pathway of each division in the brainstem circuitry. Understanding of the pathophysiology and mechanism of the TVR, together with the rapid recognition and treatment could prevent serious negative outcomes, especially when the ophthalmic nerve is stimulated.1Introduction     

Swimming exercise with l-arginine coated nanoparticles supplementation upregulated HAND2 and TBX5 expression in the cardiomyocytes of aging male rats

Biogerontology - We investigated possible cardioprotective mechanisms of l-arginine coated nanoparticles (L-ACN) combined with swimming exercise (SE) in aging male rats considering heart and neural...     

Endoscopic Orientation of the Parasellar Region in Sphenoid Sinus with Ill-Defined Bony Landmarks: An Anatomic Study

The sphenoid bony landmarks are important for endoscopic orientation in skull base surgery but show a wide range of variations. We aimed to describe an instructional model for the endoscopic parasellar anatomy in sphenoid sinuses with ill-defined bony landmarks. Five preserved injected cadaveric heads and four sides of dry skulls were studied endoscopically via transethmoid, transsphenoidal approach. The parasellar region was exposed by drilling along the maxillary nerve (V2) canal [the length of the foramen rotundum (FR) between the middle cranial fossa and the pterygopalatine fossa]. This was achieved by drilling in the inferior part of the lateral wall of posterior ethmoids immediately above the sphenopalatine foramen. Cavernous V2 was traced to the paraclival internal carotid artery (ICA). Cavernous sinus (CS) apex was exposed by drilling a triangle bounded by V2 and its canal inferiorly, bone between FR and superior orbital fissure (SOF) anteriorly, and ophthalmic nerve (V1) superiorly. Drilling was continued toward the annulus of Zinn (AZ) and optic nerve superiorly and over the intracavernous ICA posteriorly. Endoscopic measurements between V2, SOF, AZ, and opticocarotid recess were obtained. Endoscopic systematic orientation of parasellar anatomy is presented that can be helpful for approaching sphenoid sinus with ill-defined bony landmarks.     

Identification of Placebo Responsive Participants in 40km Laboratory Cycling Performance

The placebo effect, a positive outcome resulting from the belief that a beneficial treatment has been received, is widely acknowledged but little understood. It has been suggested that placebo responsiveness, the degree to which an individual will respond to a placebo, might vary in the population. The study aimed to identify placebo-responsive participants from a previously published paper that examined the effects of caffeine and placebos on cycling performance. A quantitative model of placebo responsiveness was defined. 14 male participants were subsequently classified as either placebo responsive or non-responsive. Interviews were conducted to corroborate these classifications. Secondary quantitative analyses of performance data were conducted to identify further placebo responses. Finally, the five factor model of personality was used to explore relationships between personality and placebo responsiveness. Overall, 5 of 14 participants were classified as placebo responsive. Performance data suggested that 2 participants were placebo responsive whilst 12 were not. Interview data corroborated experimental data for these participants and for 9 of the remainder, however it suggested that the remaining 3 had experienced placebo effects. Secondary quantitative analysis revealed that performance for these 3 participants, whilst no better than for non-responsive participants, was associated with substantially increased oxygen uptake in the 2 conditions in which participants believed caffeine had been administered (7.0% ± 15.1; 95% confidence intervals -2.6 to 16.7, and 6.0% ± 15.4; -3.9 to 15.9 respectively). Finally, data suggested that the personality factors of extroversion, agreeableness, openness and neuroticism may relate to placebo responding. Placebo effects such as pain tolerance and fatigue resistance might be experienced by a percentage of participants but might not always be manifest in objective measures of performance.

Key points

• Beliefs can have both positive (placebo) and negative (nocebo) effects
• Placebo effects may be experienced both objectively and subjectively
• Certain personality traits may be related to placebo responding
• A multi-method approach may best elucidate placebo effects in sport.

Key words: Caffeine, personality, placebo effect, nocebo effect, qualitative     

First live birth following IVF–embryo transfer and use of GnRHa alone for ovarian stimulation

Several case reports have shown that some patients may develop ovarian cysts or ovarian hyperstimulation syndrome following the administration of gonadotrophin-releasing hormone agonist (GnRHa). This is the first report of a live birth following ovarian stimulation and IVF–embryo transfer using sole administration of GnRHa as part of the short protocol. The 31-year-old woman was referred to IVF because of severe male factor. Following spontaneous menses, ovulation induction was started by administering a conventional flare-up regimen (triptorelin 0.1 mg) on day 1 of the cycle. On day 3, the oestradiol concentration was 444 pg/ml and the progesterone concentration was 0.3 ng/ml. On day 4, about 10 follicles, 8–10 mm in size, were detected in each ovary, and the oestradiol concentration rose to 704 pg/ml (progesterone was unchanged). Surprisingly, on day 9, the follicles were 18–19 mm in diameter, oestradiol had increased to 3678 pg/ml and progesterone was now 2.88 ng/ml. Informed consent was obtained for administering human chorionic gonadotrophin and for performing ovum retrieval 36 h later. Nineteen MII oocytes were retrieved, and all were fertilized, yielding high-quality embryos. Two embryos were transferred, and the patient conceived and recently gave birth to a healthy singleton.     

Prognosis following neonatal brachial plexus palsy: an evidence-based review

Purpose  

The spontaneous recovery rate of neonatal brachial plexus palsy (NBPP) is often cited as 75–95%. However, recent reports have found the recovery rate to be much lower. The purpose of this study was to perform an evidence-based review aimed at summarizing the available English language information regarding prognosis following NBPP based on the Narakas classification.