Influence of Water Content and Temperature on Molecular Mobility and Intracellular Glasses in Seeds and Pollen

Although the occurrence of intracellular glasses in seeds and pollen has been established, physical properties such as rotational correlation times and viscosity have not been studied extensively. Using electron paramagnetic resonance spectroscopy, we examined changes in the molecular mobility of the hydrophilic nitroxide spin probe 3-carboxy-proxyl during melting of intracellular glasses in axes of pea (Pisum sativum L.) seeds and cattail (Typha latifolia L.) pollen. The rotational correlation time of the spin probe in intracellular glasses of both organisms was approximately 10(−3) s. Using the distance between the outer extrema of the electron paramagnetic resonance spectrum (2A(zz)) as a measure of molecular mobility, we found a sharp increase in mobility at a definite temperature during heating. This temperature increased with decreasing water content of the samples. Differential scanning calorimetry data on these samples indicated that this sharp increase corresponded to melting of the glassy matrix. Molecular mobility was found to be inversely correlated with storage stability. With decreasing water content, the molecular mobility reached a minimum, and increased again at very low water content. Minimum mobility and maximum storage stability occurred at a similar water content. This correlation suggests that storage stability might be at least partially controlled by molecular mobility. At low temperatures, when storage longevity cannot be determined on a realistic time scale, 2A(zz) measurements can provide an estimate of the optimum storage conditions

Prevalence and Predictive Factors of Chronic Postsurgical Pain and Global Surgical Recovery 1 Year After Outpatient Knee Arthroscopy: A Prospective Cohort Study

Outpatient knee arthroscopy is one of the most commonly performed surgical procedures. Previous research has demonstrated that chronic postsurgical pain (CPSP) after outpatient surgery is prevalent. Our objective was to determine the prevalence and predictive factors of CPSP and Global Surgical Recovery (GSR) 1 year after knee arthroscopy.A prospective longitudinal cohort study was performed. Patients were included during an 18-month period. Data were collected by using 3 questionnaires: at 1 week preoperatively, 4 days postoperatively, and 1 year postoperatively. A value of >3 on an 11-point numeric rating scale (NRS) was defined as moderate to severe pain. A score of 80% on the Global Surgical Recovery Index was defined as poor GSR. Stepwise logistic regression analysis was performed to determine which variables were predictors for CPSP and poor GSR.The prevalence of moderate to severe preoperative pain in patients undergoing knee arthroscopy (n=104) was 71.2%, of acute postsurgical pain 37.5%, and of CPSP 32.7%. Risk factors for CPSP were the presence of preoperative pain and preoperative analgesic use, with odds ratios of 6.31 (1.25-31.74) and 4.36 (1.58-12.07), respectively. The prevalence of poor GSR 1 year after outpatient knee arthrosocpy was 50.0%. Poor GSR 4 days after the surgery was a risk factor with an odds ratio of 8.38 (0.92-76.58) and quality of life 4 days after surgery was a protective factor with and odds ratio of 0.10 (0.02-0.64).Both CPSP and poor GSR are common 1 year after knee arthroscopy. Patients at risk for CPSP can be identified during the preoperative phase. Prediction of poor GSR 1 year after surgery is mainly related to early postoperative recovery

Predictive factors of postoperative pain after day-case surgery

Objectives: Despite the growing number of ambulatory operations knowledge of predictive factors of postoperative pain after ambulatory surgery is limited. Therefore, the aim of this study was to identify predictive factors of postoperative pain after ambulatory surgery. Methods: In this cross-sectional study, 648 patients were included. A wide variety of elective ambulatory operations were performed. Pain assessments were made before the operation and during a 4-day period postoperatively, using a 100 mm visual analog scale. Patient characteristics, type of surgery. and type of anesthesia were recorded. In addition, preoperative expectations of postoperative pain by physician and patient were assessed. Finally, several scores about psychologic parameters were measured: pain catastrophizing, surgical anxiety, and optimism. Stepwise logistic regression analysis was performed to identify factors that independently predict the risk of having postoperative pain (defined by a visual analog scale >40 mm) oil days 0 to 4. Results: The most important predictor of postoperative pain was the presence of preoperative pain. Other predictors were anticipated postoperative pain by the clinician, preoperative high expectations of postoperative pain by the patient, younger age, and fear of short-term consequences of the operation. Regional anesthetic technique compared with general anesthesia decreased the risk of acute postoperative pain only oil the day of the operation. Discussion: Several predictive factors of postoperative pain after ambulatory surgery were identified in this study. These factors Should be taken into account when planning postoperative analgesia for ambulatory surgery

Continuous paravertebral block for postoperative pain compared to general anaesthesia and wound infiltration for major oncological breast surgery

We hypothesized that improved acute postoperative pain relief will be achieved using general anaesthesia (GA) either in combination with continuous thoracic paravertebral block (GA-cPVB) or single shot (GA-sPVB) as compared to GA supplemented by local wound infiltration (GA-LWI) after unilateral major breast cancer surgery. A randomised controlled trial was conducted in 46 adult women in a day-care or short-stay hospital setting after major breast cancer surgery. Pain-intensity was measured using an 11-point visual analogue scale (VAS) until postoperative day 2. GA-sPVB was stopped due to slow inclusion. No significant difference in VAS score was noted between GA-LWI (VAS median 0.5 (interquartile range 0.18-2.00)) and GA-cPVB, (VAS 0.3 (0.00-1.55, p = 0.195)) 24 hours after surgery or at any point postoperatively until postoperative day 2. We conclude that both GA-LWI and GA-cPVB anaesthetic techniques are equally effective in treatment of acute postoperative pain after major oncological breast surgery. As GA-LWI is easily to perform with fewer complications and it is more cost-effective it should be preferred over GA-cPVB

Synaptic plasticity in the substantia gelatinosa in a model of chronic neuropathic pain

Chronic neuropathic pain (CNP) is common after peripheral nerve injuries (PNI), but is rather refractory to available anti-pain medication. Advances in neuropathic pain research have identified cellular and molecular cues triggering the onset of neuropathic pain, but the mechanisms responsible for maintenance of chronic pain states are largely unknown. Structural changes such as sprouting of injured A-fibres into the substantia gelatinosa of the dorsal horn in the spinal cord have been proposed to relate to neuropathic pain in partial PNI models. Structural changes in central pain networks may also underlie the more persistent CNP following complete sectioning of a peripheral nerve, because this type of injury results in continuous and spontaneous afferent input to the spinal cord, which can trigger central sensitization. In the present study, the left sciatic nerve was completely sectioned and a 1-cm segment was removed to maintain a chronic pathology, whereas the right sciatic nerve was left intact. Mechanical allodynia was measured up to 84 days after injury, after which synaptic changes were studied in the lumbar substantia gelatinosa. The numbers of larger sized synaptophysin-immunoreactive presynaptic boutons were found to be increased in the substantia gelatinosa ipsilateral to the nerve injury. From these data we conclude that structural synaptic changes within the substantia gelatinosa are present months after complete nerve injury and that this plasticity may be involved in maintaining neuropathic pain states