Effect of blood pressure on cognitive functions in elderly persons

BACKGROUND: Little is known about what specific cognitive functions are affected by elevated blood pressure (BP) and how orthostatic BP change is related to cognitive impairment. The aim of this study was to determine the effect of BP and its postural change on cognitive functions in otherwise healthy elders. METHODS: In 70 healthy persons (mean age, 72 +/- 4 years), supine systolic BP (SBP) was assessed 3 times using a sphygmomanometer, and the average values were obtained for the analysis. After 1, 3, and 5 minutes of standing, 3 BP measurements were obtained and the orthostatic SBP changes were determined by subtracting these values from the supine average. Neuropsychological tests were administered to assess short-term and long-term verbal and visual memory, visuospatial skills, and frontal-executive functions. Participants were considered impaired in the specific cognitive performance if their scores fell below the 25th percentile of the study population. Multiple logistic regression models were used to evaluate the relation of SBP and the magnitude of orthostatic SBP decline to risk for impairment in each of the cognitive tests. RESULTS: Controlling for potential confounders, each 10 mmHg increase in supine SBP was associated with a 2.31-fold increase (95% confidence interval, 1.14 to 4.66) in risk for impairment in psychomotor speed and set shifting as measured using the Trailmaking Part-B test. There was no significant association between cognitive functions and orthostatic SBP decline at 1, 3, and 5 minutes of standing. CONCLUSION: Elevation of BP is associated with a selective impairment in executive function in otherwise healthy community-dwelling elders.     

Colon Interposition Graft for Corrosive Esophageal Stricture: Midterm Functional Outcome

Background

Corrosive esophageal stricture is a major cause of morbidity among Nigerians. In most cases, this follows accidental or parasuicidal ingestion of caustic sodium hydroxide solution (NaOH) often used in the local production of soaps. Various treatment modalities have been advocated for the treatment of esophageal stricture. In this study, we review the results of our adopted technique in the past 10 years for pedicled colonic interposition.

Methods

This is a retrospective study of 21 patients who underwent substernal isoperistaltic pedicled colonic interposition graft for management of corrosive esophageal stricture. The right colon was pulled up into the neck in all the patients without resecting the strictured esophagus.

Results

Long segment strictures and multiple strictures were the main indications for the procedure. The mean duration of the procedure was 339.6 ± 71.1 min. The average intraoperative blood loss was 673.1 ± 398.1 mL. There were two (9.5 %) hospital mortalities. Graft infarction (9.5 %), cervical fistulae (19.0 %), and reflux neo-esophagitis (14.3 %) were the main non-fatal complications. In the mid-term, dysphagia was completely relieved in a little over 84 % (16/19) of patients, while one patient (4.8 %) still experienced reflux neo-esophagitis requiring treatment. There was no case of gross regurgitation or nocturnal aspiration in the mid-term.

Conclusions

Although the use of pedicled colonic interposition graft offers a good mid-term functional outcome with relief of dysphagia, early postoperative morbidity is high. Graft infarction is the single most important factor for poor functional outcome and every effort must be made to prevent its occurrence.     

FLS tasks can be used as an ergonomic discriminator between laparoscopic and robotic surgery

Introduction

Robotic surgery may result in ergonomic benefits to surgeons. In this pilot study, we utilize surface electromyography (sEMG) to describe a method for identifying ergonomic differences between laparoscopic and robotic platforms using validated Fundamentals of Laparoscopic Surgery (FLS) tasks. We hypothesize that FLS task performance on laparoscopic and robotic surgical platforms will produce significant differences in mean muscle activation, as quantified by sEMG.

Methods

Six right-hand-dominant subjects with varying experience performed FLS peg transfer (PT), pattern cutting (PC), and intracorporeal suturing (IS) tasks on laparoscopic and robotic platforms. sEMG measurements were obtained from each subject’s bilateral bicep, tricep, deltoid, and trapezius muscles. EMG measurements were normalized to the maximum voluntary contraction (MVC) of each muscle of each subject. Subjects repeated each task three times per platform, and mean values used for pooled analysis. Average normalized muscle activation (%MVC) was calculated for each muscle group in all subjects for each FLS task. We compared mean %MVC values with paired t tests and considered differences with a p value less than 0.05 to be statistically significant.

Results

Mean activation of right bicep (2.7 %MVC lap, 1.3 %MVC robotic, p = 0.019) and right deltoid muscles (2.4 %MVC lap, 1.0 %MVC robotic, p = 0.019) were significantly elevated during the laparoscopic compared to the robotic IS task. The mean activation of the right trapezius muscle was significantly elevated during robotic compared to the laparoscopic PT (1.6 %MVC lap, 3.5 %MVC robotic, p = 0.040) and PC (1.3 %MVC lap, 3.6 %MVC robotic, p = 0.0018) tasks.

Conclusions

FLS tasks are validated, readily available instruments that are feasible for use in demonstrating ergonomic differences between surgical platforms. In this study, we used FLS tasks to compare mean muscle activation of four muscle groups during laparoscopic and robotic task performance. FLS tasks can serve as the basis for larger studies to further describe ergonomic differences between laparoscopic and robotic surgery.     

Changes in the pathogenicity of relapsed diminazene aceturate (DA)-resistant Trypanosoma brucei brucei as the trypanosomes are transmitted from DA-treated hosts to another set of animals

This study investigated the changes in pathogenicity of relapsed diminazene aceturate (DA)-resistant Trypanosoma brucei brucei (TBB) as the trypanosomes are transmitted from DA-treated hosts to another set of animals. The Federe strain of T. brucei brucei which was known to be DA resistant was used to infect two groups of rats, one of which was treated at the peak of infection. There was temporary clearance of the trypanosomes from blood of the treated group and subsequent relapse of the infection. The relapsed trypanosomes were used to infect a group of rats (group A1), and the pathogenicity of the relapsed T. brucei brucei in this rat group was compared to that of a group infected with primary T. brucei brucei stock that was not treated with DA (group B1). Results showed that when compared with the B1 rats, the A1 group had a slower onset of parasitaemia, significantly lower (p < 0.01) level of parasitaemia all through the study, significantly longer (p < 0.01) time period to reach peak parasitaemia, significantly longer (p < 0.01) post-infection survival time and significantly higher (p < 0.05) packed cell volume from day 6 post-infection. Further sequential transmission of this same T. brucei brucei infection to another group of rats (A2 and B2) produced the same effects on the above parameters used to assess pathogenicity. It was concluded that beyond temporarily clearing trypanosomes from blood of treated animals, treatment with DA reduces the pathogenicity of DA-resistant T. brucei brucei, and this reduced pathogenicity is carried on as the T. brucei brucei is further sequentially transmitted to another set of animals.     

Spleen morphology and hematological changes in rats following withdrawal of Nigerian Qua Iboe Brent crude oil

Possible amelioration of splenic damage and hematological changes in Nigerian Qua Iboe Brent crude oil-exposed rats following its withdrawal was investigated. A total of 56 male albino rats weighing between 200–250 g were used for this study. The rats received oral administration of 165 mg/kg body weight (low-dose), 330 mg/kg body weight (medium-dose) and 660 mg/kg body weight (high-dose) of Nigerian Quo Iboe Brent crude oil every 48 h for 28 days. Later, the crude oil was withdrawn from some rats for a period of 8 weeks. Hematological parameters and spleen morphology of rats that received crude oil and the rats from which the crude oil was withdrawn were compared with the controls that did not receive crude oil treatment. Administration of Nigerian Qua Iboe Brent crude oil significantly (p < 0.05) reduced the PCV levels in low-dose, low-dose crude oil-withdrawn, medium-dose crude oil-withdrawn, high-dose, and high-dose crude oil-withdrawn groups of rats. The EC was also reduced significantly (p < 0.05) in the medium- and high-dose groups of rats. In the same manner, TWBC was significantly (p < 0.05) reduced in the medium-dose crude oil-withdrawn, high-dose, and high-dose crude oil-withdrawn rats. It was only at low-dose level, after 8 weeks of crude oil withdrawal that there was a reduction in splenic weight. Splenic section (histopathology) of rats exposed to different doses of crude oil over 28-day period showed reticuloendothelial hyperpasia of the red pulp and variable degree of haemosiderin deposits. These changes were not completely ameliorated after 8 weeks of crude oil withdrawal. This study has shown that withdrawal of Nigerian Qua Iboe Brent crude oil from exposed rats did not reverse the splenic damage and the haematologic changes associated with this environmental pollutant.     

Responses of pulmonary platelet-derived growth factor peptides and receptors to hyperoxia and nitric oxide in piglet lungs

The peptides platelet-derived growth factor-A (PDGF-A) and especially -B have important roles in lung development. The effect of hyperoxic exposure with and without inhaled nitric oxide (iNO) on lung expression of PDGF and its receptors is unknown. We hypothesized that hyperoxia exposure would suppress mRNA expression and protein production of these ligands and their receptors. The addition of iNO to hyperoxia may further aggravate the effects of hyperoxia. Thirteen-day-old piglets were randomized to breathe 1) room air (RA); 2) 0.96 fraction of inspired oxygen (O2), or 3) 0.96 fraction of inspired oxygen plus 50 ppm of NO (O2+NO), for 5 d. Lungs were preserved for mRNA, Western immunoblot, and immunohistochemical analyses for PDGF-A and -B and their receptors PDGFR-alpha and -beta. PDGF-B mRNA expression was greater than that of PDGF-A or PDGFR-alpha and -beta in RA piglet lungs (p<0.05). Hyperoxia with or without iNO reduced lung PDGF-B mRNA and protein expression relative to the RA group lungs (p<0.01). PDGF-B immunostain intensity was significantly increased in the alveolar macrophages, which were present in greater numbers in the hyperoxia-exposed piglet lungs, with or without NO (p<0.01). PDGFR-beta immunostaining was significantly increased in airway epithelial cells in O2- and O2+NO-exposed piglets. PDGF-A and PDGFR-alpha immunostain intensity and distribution pattern were unchanged relative to the RA group. Sublethal hyperoxia decreases PDGF-B mRNA and protein expression but not PDGF-A or their receptors in piglet lungs. iNO neither aggravates nor ameliorates this effect.     

Endostatin and vascular endothelial cell growth factor (VEGF) in piglet lungs: effect of inhaled nitric oxide and hyperoxia

Pulmonary hyperoxic injury manifests as widespread alveolar-epithelial and microvascular endothelial cell necrosis, resolution of which requires angiogenesis. We investigated the hypothesis that inhaled nitric oxide (iNO) and hyperoxia each decreases lung vascular endothelial growth factor (VEGF) expression but increases endostatin and that concurrent administration of both gases will show a greater effect. Piglets were randomized to breathe for 5 d room air (RA); RA + NO (RA + 50 ppm NO), O(2) (hyperoxia, F(I)O(2) >0.96), O(2) + NO, or O(2) + NO + REC (O(2) + NO plus recovery in 50% O(2) for 72 h. After the piglets were killed, we measured lung capillary leak, VEGF mRNA, VEGF, and endostatin protein in homogenates, plasma, and lavage. VEGF mRNA decreased significantly with O(2) and O(2) + NO compared with breathing RA (p < or = 0.05). VEGF protein declined in the experimental groups with a significant reduction in the recovery group compared with the RA group (p < or = 0.05). Similar but more dramatic, endostatin declined in all groups relative to the RA group (p < 0.001). Lavage fluid VEGF protein and lung capillary leak rose significantly with O(2) and O(2) + NO compared with RA, but endostatin was unchanged. At 72 h of recovery from hyperoxia, VEGF mRNA and lavage fluid VEGF but not lung VEGF protein had normalized. Hyperoxia and iNO suppresses lung endostatin expression, but iNO unlike hyperoxia alone does not alter lung VEGF production. Hyperoxia paradoxically raises lavageable VEGF levels. This latter effect and that on VEGF mRNA level but not protein is abrogated by recovery in reduced F(I)O(2) for 72 h.     

Effect of experimental feeding of Codiaeum variegatum leaves on growth, hematology, gonadal, and extra-gonadal sperm reserves of adult albino rats

Twenty-four male adult albino rats, weighing between 130 and 239 g, were randomly divided into four groups of six rats per group (A to D). The rats were fed either normal pelleted commercial feed containing 14.5% crude protein alone (group A) or feed supplemented with pulverized dry leaves of Codiaeum variegatum (garden croton) at the levels of 0.25% (B), 0.5% (C), and 1.0% (D). All four groups of rats were fed for 12 weeks, during which period clean water was provided ad libitum. Every 2 weeks, body weights of individual rats were taken and blood collected for hematology (packed cell volume (PCV), total and differential leukocyte counts). Hemoglobin concentration was determined at 4-week intervals. At the end of the 12-week study period, all rats were sacrificed; testes and epididymes of individual rats were weighed separately to calculate the organosomatic index for both organs. Thereafter, testicular and epididymal sperm counts were performed. Supplementing rat feed with C. variegatum leaves in treated groups (B, C, and D) resulted in reduced weight gain such that by the 12th week of study, the mean body weight of group D rats was significantly lower than that of the unsupplemented control (group A) rats. The testicular and epididymal organosomatic index for the different treatment groups were not significantly (P?>?0. 05) different from the mean values for group A rats. The hematological evaluation of the rats showed that supplementation at any of the level used did not significantly (P?>?0. 05) alter the mean PCV values. The mean total leukocyte and the mean absolute neutrophil counts (by the fourth week) for the treated groups were significantly (P?<?0. 05) higher than the corresponding values for the control groups. Likewise, the mean hemoglobin concentration for the treated groups was only slightly lower than the mean values for the control group for the greater part of the study period. The mean testicular sperm counts for the treated rat groups were generally lower in a dose-dependent manner, but was not significantly different (P?>?0.05) from the mean values for the control group. On the other hand, the mean epididymal sperm counts for the treated rat groups were significantly (P?<?0. 05) lower than the mean values for the control in a dose-dependent pattern. This study has shown that feeding male rats in particular and probably other animals in general on the leaves of garden croton at a level as low as 0.25% level of supplementation has the tendency to stimulate the immune function of animals but could severely reduce the testicular and epididymal sperm reserve counts, thereby reducing the reproductive efficiency of male animals. These results recommend further studies in respect to the immunostimulating and spermatotoxic properties of the leaves of this plant.