Use of HSI to measure oxygen saturation in the lower limb and its correlation with healing of foot ulcers in diabetes.

AIM: To explore the use of hyperspectral imaging (HSI) to predict healing of diabetic foot ulcers in patients with diabetes. METHODS: We used a HSI technique that incorporated novel software to account for tissue scattering of light, and was validated using blood samples of varying oxygen saturation assessed by blood gas analysis. HSI was then performed on a population newly presenting with diabetic foot ulcers to a specialist clinic, and associations were sought with healing at 12 and 24 weeks. RESULTS: The correlation between the results of HSI and blood gas analysis was strong (r = 0.994). A total of 43 patients (mean ± sd age 62.7 ± 12.2 years; 31 men, 12 women; 37 with Type 2 diabetes, six with Type 1 diabetes) with foot ulcers were included in the prospective clinical study and underwent HSI within 16 days of presentation. In all, 26 ulcers healed within 12 weeks and 28 within 24 weeks. There was a negative association between tissue oxygenation assessed by HSI at baseline and healing by 12 weeks (P = 0.009), and this was observed in both infected and non-infected ulcers. There was a significant positive correlation between oxygenation assessed by HSI and time to healing (P = 0.03). No correlations were observed at 24 weeks. CONCLUSIONS: These findings suggest that HSI may predict healing in routine practice. The fact that the correlation between HSI and healing was negative could be explained by HSI being a measure of oxygenation of haemoglobin and there may be an inverse relationship between this and the oxygenation of extravascular tissue in people with neuropathy and/or microvascular disease.

Measuring pharmacovigilance knowledge and attitudes among healthcare sciences students: development and validation of a universal questionnaire.

OBJECTIVE: Pharmacovigilance education and reporting of adverse drug reactions (ADRs) are important competencies that healthcare sciences students should develop before completing their studies and entering clinical practice. Since students frequently lack adequate knowledge in this area and fail to recognize the importance of ADRs monitoring and reporting, the aim of this study was to develop and validate a unique and reliable instrument for assessing health sciences students' knowledge and attitudes toward pharmacovigilance and ADRs reporting. SUBJECTS AND METHODS: A cross-sectional observational study was conducted from February to July 2021 to examine students' knowledge and attitudes toward pharmacovigilance activities. Students of medicine, dentistry, pharmacy, and nursing science of three faculties in the Autonomous Province of Vojvodina, Serbia were examined. A total of 211 of them completed the specially designed, three-section questionnaire (Demographic data section, Pharmacovigilance Knowledge test, PVKT, and Pharmacovigilance Attitude Questionnaire, PVAQ). The questionnaire was posted on the Google Forms platform, and the link was distributed to respondents via the official websites and social networks of all three faculties. RESULTS: Findings demonstrated good psychometric properties and reliability of the questionnaire. Six questions were removed from the PVKT after item analyses. After excluding these items, the calculated ordinal alpha of the final version of the PVKT, which included 14 items, was good (αord = 0.83), as were other statistical indicators. PVAQ reliability testing also revealed great performance of this questionnaire-calculated ordinal alpha for two PVAQ subscales was excellent (αord = 0.91, for both scales). CONCLUSIONS: This questionnaire has favorable validity and reliability in assessing healthcare sciences students' knowledge and attitudes toward pharmacovigilance and ADRs reporting.

COVID-19 associated pulmonary embolism with D-dimer values within the referent range: a case report and review of the literature.

OBJECTIVE: COVID-19 is associated with an increased incidence of pulmonary embolism (PE). Elevated D-dimer levels are linked to an increased risk of PE and poor clinical outcome. We reported a case of PE in a COVID-19 patient with normal D-dimer levels and conducted a review of the literature on the subject. CASE REPORT: A 38-year-old man with no prior comorbidities returned to the COVID-19 outpatient clinic 36 hours after being discharged from the hospital, where he had been treated for COVID-19 pneumonia. He reported a sudden feeling of dyspnea and chest pain. The physical examination was unremarkable. No new changes were detected on the chest X-ray. D-dimer and cardiac-specific markers values were within the referent range. The patient underwent an urgent computerized tomography pulmonary angiography which revealed signs of bilateral arterial thrombosis. He was treated with a therapeutic dose of low molecular weight heparin and discharged after 15 days, with a recommendation to use a direct oral anticoagulant. CONCLUSIONS: Healthcare professionals should be aware that PE can occur as a late complication of COVID-19. Clinical suspicion of PE should lead physicians to use additional diagnostic methods to confirm or rule out PE, even if D-dimer levels are within the referent range.

Effects of bright light and melatonin on sleep propensity, temperature, and cardiac activity at night.

Melatonin increases sleepiness, decreases core temperature, and increases peripheral temperature in humans. Melatonin may produce these effects by activating peripheral receptors or altering autonomic activity. The latter hypothesis was investigated in 16 supine subjects. Three conditions were created by using bright light and exogenous melatonin: normal endogenous, suppressed, and pharmacological melatonin levels. Data during wakefulness from 1.5 h before to 2.5 h after each subject's estimated melatonin onset (wake time + 14 h) were analyzed. Respiratory sinus arrhythmia (cardiac parasympathetic activity) and preejection period (cardiac sympathetic activity) did not vary among conditions. Pharmacological melatonin levels significantly decreased systolic blood pressure [5.75 +/- 1.65 (SE) mmHg] but did not significantly change heart rate. Suppressed melatonin significantly increased rectal temperature (0.27 +/- 0.06 degrees C), decreased foot temperature (1.98 +/- 0.70 degrees C), and increased sleep onset latency (5.53 +/- 1.87 min). Thus melatonin does not significantly alter cardiac autonomic activity and instead may bind to peripheral receptors in the vasculature and heart. Furthermore, increases in cardiac parasympathetic activity before normal nighttime sleep cannot be attributed to the concomitant increase in endogenous melatonin.

Reduced customary activity in chronic heart failure: assessment with a new shoe-mounted pedometer.

Although many methods exist to assess the degree of incapacity of patients with chronic heart failure during normal daily activities, all have their limitations. In this study we describe a new shoe-mounted pedometer and compare it with body worn pedometers in normal volunteers and in patients with chronic heart failure. Ten young normal healthy volunteers participated in a comparison of the new shoe-mounted device with body born pedometers and counting a direct footfall. Seventeen patients with chronic heart failure and 10 aged-matched healthy elderly subjects participated in a comparison of both pedometers over 7 days. In the young volunteers the shoe-mounted pedometers were more accurate than the body-borne devices. With both pedometers the patients with chronic heart failure had a reduced level of activity compared with the normal volunteers over the 1 week period (P = 0.01). In both the patients and volunteers the shoe-mounted device recorded a higher score than the body borne pedometers (P < 0.01). The electronic shoe mounted pedometers are a more accurate way of assessing customary activity. In patients with chronic heart failure customary activity is substantially reduced compared with fit healthy elderly subjects.

Novel H1N1 influenza in neonates: from mild to fatal disease.

Analysis of pediatric deaths associated with pandemic A H1N1 influenza shows that fatal outcome is more likely in young children, under the age of 5. Neonates, because of the immaturity of their immune system, could represent a high-risk group for severe disease and fatal outcome. We present a group of five neonates with confirmed novel influenza A H1N1 infection. This report indicates that the full spectrum of influenza A H1N1 infection ranging from mild febrile illness with spontaneous recovery to severe disease with fatal outcome may be expected even in neonates.

Delayed hemolytic transfusion reaction due to anti-Jk(a).

BACKGROUND: Kidd antibodies are very heterogeneous and difficult to detect. They have been frequently implicated in delayed hemolytic transfusion reactions (DHTRs). CASE REPORT: A 64 year old female (6 pregnancies, 2 deliveries, 4 abortions) with none red cell (RBC) transfusions in the history was admitted to hospital due to pneumonia and severe anemia. On admittance hemoglobin (Hb) level was 63g/L and hematocrit (Ht) 0.21 L/L. The blood sample of the patient was sent to laboratory for serologic testing since RBC transfusions were required. Patient appeared to beO Rh(D)+ with negative both direct antiglobulin (DAT) and routine antibody screen (ID-DiaCell I+II+III-P). Three units of packed RBCs with negative crossmatch (tube method) were prepared. Patient received two units on Day 2 and one more on Day 3 without any discomfort. Hematological values after the third unit were: Hb 116g/L and Ht 0.37 L/L. On Day 6 she started to feel week, tired, with nausea and mild jaundice. Her Hb and Ht had dropped to 99 g/L and 0.33 L/L respectively, with tendency of dropping further (Day 7: Hb 83 g/L, Ht 0.26 L/L). Total serum bilirubin was 58.9 umol/L (normal range 20.5 umol/L) and direct fraction was 14.9 umol/L (normal range 7 umol/L). DTHR was suspected. Antibody identification performed by ID-DiaMed Gel Techique (GT) showed the presence of anti-Jk(a) with dosage phenomenon. All three previously transfused units were typed Jk(a) and the patient s RBCs were Jk(a-b+). She received two units of Jk(a) negative packed RBCs and was well enough to be discharged on Day 14. CONCLUSION: It is important to monitor clinical effect of transfusion regularly and to provide good team work between specialists of transfusion medicine and related medical staff. The policy of transfusion practice is to keep pretransfusion sample for three weeks and to perform cross-match tests on the samples no older then 24h and 48h respectively.

[Early results in the surgical treatment of Crawford type IV thoracoabdominal aneurysms].

OBJECTIVE: The aim of the study was to present the outcome of surgical treatment of patients with thoracoabdominal aortic aneurysm Crawford type IV, operated on between January 2001 and April 2004. METHODS: This study included 42 subsequent patients (40 males, 2 females, age 41-76 years). All patients underwent ultrasonography, angiography, computed tomography or magnetic resonance imaging (MRI). Surgical treatment was performed under combined anaesthesia (continuous thoracic epidural analgesia and general endotracheal anaesthesia). In two patients thoracophrenolumbotomy was performed at the level of X rib, while others were operated through left lumbotomy after the extra pleural resection of XI rib. We did not perform any spinal cord protection procedures in this type of aneurysm. Reconstruction included interposition of Dacron graft in 20 patients, aortobiiliac bypass in 18, and aortobifemoral bypass in 4 patients with different varieties of visceral branches reimplantation. RESULTS: Thirty-days mortality was 31% (13 patients, two of them intraoperatively). Causes of death were: pulmonary embolism--in 1 patient; haemorrhage--in 2; myocardial infarction--in 4 (two intraoperative); acute renal failure--in 2; multisystem organ failure (MSOF)--in 4 patients. Respiratory failure dominated in all cases of MSOF. One patient with acute renal failure had paraplegia also, and that was the only case of neurological complication in whole group. All female patients (2), all patients with ruptured aneurysm (4), acute myocardial infarction (4) and acute renal failure (2) have died. Advanced age (over 70 years) and the need for extensive operative procedure with bifurcated graft use significantly influenced their mortality (p < 0.01 and p < 0.05 respectively). CONCLUSIONS: Surgical treatment of thoracoabdominal aortic aneurysm Crawford IV type was successful in 69% of our patients. There was no need for spinal cord protection measures, and extra peritoneal approach with XI rib resection under the combined anaesthesia was preferred.

Electrophysiological characterization of "giant" cells in stratum radiatum of the CA3 hippocampal region.

Whole cell patch-clamp recording and intracellular staining with biocytin allowed the morphological and electrophysiological characterization of "giant" cells, studied in stratum (st.) radiatum of the CA3 region in 17- to 21-day-old rat hippocampal slices. These neurons had extensive dendritic arborization, a triangular soma, and a bipolar vertical orientation with axons directed to the pyramidal layer or extended into the st. oriens. Giant cells had significantly higher input resistance and shorter action potentials compared with CA3 pyramidal cells. Evoked action potentials were typically followed by an afterdepolarizing potential (ADP). During depolarizing current injection, most (80%) of recorded giant cells displayed a regular firing pattern (maximum steady-state firing rate, approximately 30 Hz) characterized by a modest early accommodation, whereas irregular firing was observed in the remaining 20% of giant cells. Hyperpolarizing current pulses induced a slow inward rectification of the electrotonic voltage responses, blocked by 2 mM external Cs(+). N-methyl-D-aspartate (NMDA) and non-NMDA-mediated excitatory postsynaptic currents (EPSCs) measured under voltage clamp were distinguished on the basis of their voltage dependence and sensitivity to specific NMDA and non-NMDA glutamate receptor blockers. Non-NMDA EPSCs possessed a linear current-voltage relationship. EPSCs elicited by st. lucidum stimulation were reversibly reduced (mean, 23%) by the group II metabotropic glutamate receptor agonist (2S, 1'R, 2'R, 3'R)-2-(2,3-dicarboxyl-cyclopropyl)-glycine (DCG-IV, 1 microM). GABA(A)-mediated postsynaptic currents were subject to paired-pulse depression that was inhibited by the GABA(B) antagonist CGP 55845A (5 microM). We conclude that CA3 giant cells represent a particular class of hippocampal neuron located in st. radiatum that shares only some morphological and physiological properties with principal cells.

Intracellular calcium stores modulate miniature GABA-mediated synaptic currents in neonatal rat hippocampal neurons.

The whole-cell configuration of the patch clamp technique was used to record miniature gamma-aminobutyric acidA (GABAA) receptor-mediated currents (in tetrodotoxin, 1 microM and kynurenic acid 1 mM) from CA3 pyramidal cells in thin hippocampal slices obtained from postnatal (P) day (P6-9) old rats. Switching from a Ca2+-containing to a nominally Ca2+-free medium (in which Ca2+ was substituted with Mg2+, in the presence or in the absence of 100 microM EGTA) did not change significantly the frequency or amplitude of miniature events. Superfusion of thapsigargin induced a concentration-dependent increase in frequency but not in amplitude of tetrodotoxin-resistant currents that lasted for the entire period of drug application. Mean frequency ratio (thapsigargin 10 microM over control) was 1.8+/-0.5, (n = 9). In nominally Ca2+-free solutions thapsigargin was ineffective. When bath applied, caffeine (10 mM), reversibly reduced the amplitude of miniature postsynaptic currents whereas, if applied by brief pressure pulses, it produced an increase in frequency but not in amplitude of spontaneous GABAergic currents. Superfusion of caffeine (10 mM) reversibly reduced the amplitude of the current induced by GABA (100 microM) indicating a clear postsynaptic effect on GABAA receptor. Superfusion of ryanodine (30 microM), in the majority of the cells (n = 7) did not significantly modify the amplitude or frequency of miniature events. In two of nine cells it induced a transient increase in frequency of miniature postsynaptic currents. These results indicate that in neonatal hippocampal neurons, mobilization of calcium from caffeine-ryanodine-sensitive stores facilitates GABA release.

Medium afterhyperpolarization and firing pattern modulation in interneurons of stratum radiatum in the CA3 hippocampal region.

Stratum (st.) radiatum interneurons represent a heterogeneous class of hippocampal cells with as yet poorly characterized physiological properties. Intracellular staining with biocytin, in situ hybridization, and patch-clamp recording have been combined to investigate the morphological and electrophysiological properties of these cells in the CA3 hippocampal region in young rats [postnatal days 10 to 21 (P10-21)]. Labeled cells presented a heterogeneous morphology with various soma shapes, often found multipolar, and dendritic arborizations confined to st. radiatum. The passive membrane properties of these st. radiatum interneurons showed instead no significant differences between P10 and P21. Low resting potential, high-input resistance, and short time constants characterized CA3 st. radiatum interneurons, which were silent at rest. Action potentials, elicited by brief current pulses, were lower and shorter than in pyramidal cells and followed by a Ca(2+)-dependent medium-duration afterhyperpolarizing potential (mAHP). Prolonged depolarizing current injection generated trains of action potentials that fired at constant frequency after a slight accommodation. The maximum steady-state firing rate was 31 +/- 4 (SD) Hz. Hyperpolarizing current pulses revealed a prominent inward rectification characterized by a "sag," followed by a depolarizing rebound that triggered action potentials. Sag and anodal brake excitation were blocked by Cs(+), suggesting that they were mediated by a hyperpolarization-activated cation conductance (I(h)). In the presence of tetrodotoxin and tetraethylammonium, biphasic tail currents were elicited in voltage clamp after a depolarizing step inducing Ca(2+) influx. Tail currents presented a fast Ca(2+)-activated and apamin-sensitive component (I(AHP)) and were further reduced by carbachol. The presence of I(AHP) was consistent with the high expression level of the apamin-sensitive SK2 subunit transcript in CA3 st. radiatum interneurons as detected by in situ hybridization. Different pharmacological agents were shown to affect the afterhyperpolarizing potential as well as the firing properties of st. radiatum interneurons. Exposure to Ca(2+)-free solutions mainly affected the late phase of repolarization and strongly reduced the mAHP. The mAHP was also attenuated by carbachol and by apamin, suggesting it to be partly mediated by I(AHP). Reduction of the mAHP increased the interneuron firing frequency. In conclusion, st. radiatum interneurons of CA3 hippocampal region represent a class of nonpyramidal cells with action potentials followed by an AHP of relatively short duration, partially generated by apamin and carbachol-sensitive conductances involved in the regulation of the cell firing rate.

Facilitation of miniature GABAergic currents by ruthenium red in neonatal rat hippocampal neurons.

The whole cell configuration of the patch-clamp technique was used to study the modulation gamma-aminobutyric acid (GABA)-mediated postsynaptic currents by ruthenium red in CA3 hippocampal neurons in slices obtained from postnatal (P) days P6-P10 old rats. In the presence of kynurenic acid (1 mM), ruthenium red (100 microM) completely blocked stimulus-elicited GABA-mediated postsynaptic currents and reduced by 50% the amplitude of the spontaneous ones. Ruthenium red (100 microM) increased the frequency but not the amplitude of miniature GABAergic currents recorded in the presence of tetrodotoxin (1 microM) and kynurenic acid (1 mM), an effect that was prevented by heparin (100 microM). Ruthenium red did not modify the kinetics of miniature postsynaptic currents and the currents induced by exogenous application of GABA (10 microM) in the presence of tetrodotoxin, suggesting that its action was presynaptic in origin. The effects of ruthenium red on quantal GABA release was independent of external calcium. In a nominally Ca2+-free solution the potentiating effect induced by this polyvalent cation on miniature postsynaptic currents was still present. Intracellular calcium stores were not involved in ruthenium red action, because this polyvalent cation was able to facilitate miniature currents also in the presence of thapsigargin (10-20 microM). These results indicate that ruthenium red has a dual action on GABA release from GABAergic interneurons: it reduces the amplitude of spontaneous events and increases the frequency of miniature currents. The former effect is calcium-dependent, whereas the latter is calcium independent.

[Acute hemolytic transfusion reaction]. / Akutna transfuziona hemolizna reakcija.

Alloogenous blood and/or corresponding haemoproduct transfusion is an efficient and relatively safe supportive treatment. Despite the fact that pre transfusion investigation of both patients and donors ensure high degree of safety of this type of treatment, occurrence of adverse haemotherapy effects is possible and often unpredictable. Acute haemolytic transfusion reaction occur as a consequence of immune conflict between red blood cell membrane agents and specific antibodies present in plasma. Since it is impossible to completely avoid the occurrence of transfusion reactions, wherein acute transfusion haemolytic reaction present a serious, possibly life threatening complication, it is an imperative to continue to improve the knowledge on pathogenesis mechanisms leading to complications associated with these reaction and to define the most efficient therapeutical modalities.

[Acute transfusion-related lung injury]. / Akutno ostecenje pluca izazvano transfuzijom (transfusion related acute lung injury--TRALI).

Transfusion Related Acute Lung Injury (TRALI) is the most serious, potentially lethal, transfusion reaction caused by anti leukocyte antibodies carried passively into recipient's circulation by transfused haemoproduct. It is manifested most frequently within first four hours after transfusion of allogenous haemoproduct containing anti leukocyte antibodies. It is characterized with symptoms and signs of acute respiratory distress syndrome. This rare, but severe transfusion reaction with mortality rate of around 10% is often misdiagnosed, since TRALI signs are assigned to other clinical conditions. Thus, an education for timely recognition and urgent care of TRALI should be initiated.

The effects of bright light and nighttime melatonin administration on cardiac activity.

Although melatonin has an important physiological role in the facilitation of sleep, its precise mechanism of action is not clear. To investigate the potential contribution of melatonin to influence cardiac autonomic activity in the evening, 16 young healthy subjects participated in a repeated measures design where cardiac autonomic activity, heart rate and blood pressure were examined during three experimental conditions. An initial baseline condition involved dim light exposure (< 10 lux), permitting the normal nocturnal rise in endogenous melatonin. In other sessions, subjects were exposed to bright light (> 3000 lux) to suppress melatonin secretion and administered a placebo or melatonin (5 mg) capsule at the estimated time of increase in endogenous melatonin (wake time + 14 hours). Heart rate, pre-ejection period (a measure of cardiac sympathetic activity) and respiratory sinus arrhythmia (a measure of parasympathetic activity) were not significantly altered in response to the three melatonin levels. While melatonin had no effect on diastolic blood pressure, systolic blood pressure was maximally decreased by 6 +/- 1.93 mmHg (mean +/- SEM, p < 0.005) 150 minutes after exogenous melatonin. The results indicate that melatonin does not directly modulate cardiac autonomic activity, but may rather act directly on the cardiovascular system.

Role of autologous fibrin tissue adhesive in abdominal surgery.

Fibrin tissue adhesive (FTA) is an agent developed for achieving better hemostasis and adhesion of living tissue. FTA appears to have no tissue toxicity, promotes a firm seal in seconds to minutes, is reabsorbed in days to weeks following application, and appears to promote local tissue growth and repair. It can be used in various surgical procedures. It has been used preoperatively, perioperatively and postoperatively in abdominal surgical procedures. There were no side effects. Improvement of surgical hemostasis was obvious in all patients. Anastomotic leakages were closed in a shorter time without surgical intervention. Sero-lymphatic drainage after surgical procedures that include extensive lymph node dissections was less. Use of FTA in treatment of fistula in ano was successful. The data would indicate that use of FTA may be a good alternative in solving various conditions in every day clinical practice, although a bigger randomized series, and longer follow up is needed.