Accuracy of the Minicardio system for heart rate variability analysis compared to ECG.

AIM: The purpose of this investigation was twofold: firstly, to assess the accuracy of heart rate (HR) measurements from Minicardio compared to a standard electrocardiogram (ECG) and secondly, to compare the heart rate variability analysis carried out for each set of data. METHODS: Fifteen young participants volunteered for this study and were instrumented for the simultaneous recording of HR via ECG and Minicardio. HR was recorded continuously during 10 minutes of supine rest and 2 consecutive exercise bouts (target HR at 130 bpm and 150 bpm). R-R intervals were determined in order to compare the number and type of artifacts in each data set. The device were then compared by determining the type and number of artifacts, correlations between HRV analysis parameters and Bland-Altman limits of agreement. RESULTS: No artifact was produced from ECG. With Minicardio, no artifact was produced during supine rest, during exercise there were 2 type 1 (long R-R interval) and 7 type 2 artifacts (short R-R interval). For time domain analysis, Pearson coefficients were 1 for SDNN and mean R-R interval and 0.99 for RMSSD and pNN50. For frequency domain analysis, Pearson coefficients were 0.99 for high frequency and low frequency power, and 0.99 for Poincaré plots SD1 and SD2. Limits of agreement from Bland-Altman analysis showed an excellent agreement between all devices CONCLUSION: The similarity between ECG and Minicardio encourages us to use Minicardio as a portable HR recorder for subjects at rest and during moderate cycling exercise.

Immunosuppression-mediated hepatitis B reactivation diagnosed following an investigation into suspected transfusion-transmitted hepatitis B.

In August 2006, the regional unit for nosocomial infection control (ARLIN) was notified of a case of symptomatic acute hepatitis B (HBV) infection in an immunosuppressed 87-year-old patient who had received a blood transfusion five months previously. Immunosuppression for the treatment of a variety of conditions is increasing. Immunosuppressed patients should be investigated for previous HBV infection and given pre-emptive therapy where indicated. We report our experience investigating a case of HBV reactivation in an immunosuppressed patient. We describe the investigation and highlight the continued need for vigilance for HBV reactivation in immunosuppressed patients who may present to a range of clinicians.

Do irrelevant sounds impair the maintenance of all characteristics of speech in memory?

Several studies have shown that maintaining in memory some attributes of speech, such as the content or pitch of an interlocutor's message, is markedly reduced in the presence of background sounds made of spectrotemporal variations. However, experimental paradigms showing this interference have only focused on one attribute of speech at a time, and thus differ from real-life situations in which several attributes have to be memorized and maintained simultaneously. It is possible that the interference is even greater in such a case and can occur for a broader range of background sounds. We developed a paradigm in which participants had to maintain the content, pitch and speaker size of auditorily presented speech information and used various auditory distractors to generate interference. We found that only distractors with spectrotemporal variations impaired the detection, which shows that similar interference mechanisms occur whether there are one or more speech attributes to maintain in memory. A high percentage of false alarms was observed with these distractors, suggesting that spectrotemporal variations not only weaken but also modify the information maintained in memory. Lastly, we found that participants were unaware of the interference. These results are similar to those observed in the visual modality.

Laparoscopic repair of a large interstitially incarcerated inguinal hernia.

A 68 year old female presented for elective repair of an abdominal wall hernia. Preoperative CT imaging revealed a right inguinal hernia defect with hernia contents coursing cephalad between the external and internal abdominal oblique muscles. This was consistent with an interstitial inguinal hernia, a rare entity outside of post- traumatic hernias. At operation the hernia contents were reduced laparoscopically. The hernia was then repaired by transitioning to the totally extraperitoneal (TEP) approach using a 15cm X 15cm piece of polyester mesh. The patient had an uneventful recovery. Interstitial hernias are rare, difficult to diagnose and potentially dangerous if left untreated. There is no consensus on the ideal repair of these unique hernias. This represents a minimally invasive repair of an unusual hernia, with a novel approach to diagnose and manage the hernia and its redundant sac.

Evaluation of lyophilized platelets as an infusible hemostatic agent in experimental non-compressible hemorrhage in swine.

INTRODUCTION: Human lyophilized platelets hold promise as a novel hemostatic infusion agent for the control of traumatic hemorrhage. Rehydrated, lyophilized platelets (Stasix) were investigated as an infusible hemostatic agent in experimental non-compressible hemorrhage, using a porcine liver injury model. METHODS: Yorkshire swine underwent a grade III liver injury and uncontrolled bleeding. After 15 min, animals were infused with Stasix (n = 10) or normal saline vehicle (n = 10). At 2 h, the liver was repaired, and the animals were monitored for another4 h. Resuscitation, including blood transfusion, was administered during the hospital phase. Laboratory data, including arterial blood gas, complete blood count, thromboelastography (TEG), and coagulation parameters, were collected. All animals underwent necropsy with complete histopathologic examination. RESULTS: Overall survival in the Stasix group [8/10 (80%)] was significantly higher than in the control group [2/10 (20%)] (P = 0.023). Mean total blood loss index (g kg(-1)) was lower in Stasix-treated animals (22.2 +/- 3.5) than in control animals (34.7 +/- 3.4) (P = 0.019). Hemodynamic parameters were improved in the Stasix group, and a trend towards higher hemoglobin and lower lactate was observed. Coagulation and TEG parameters were not different between the groups. One surviving animal in the Stasix group had evidence of thrombi on necropsy. CONCLUSIONS: This is the first reported study to evaluate rehydrated, lyophilized platelets as an infusible hemostatic agent for non-compressible hemorrhage. Stasix improved survival and reduced blood loss in a liver injury porcine model. However, evidence of thrombotic complications warrants further investigation prior to human use in the setting of traumatic hemorrhage.

Organisation of the mouse and human 5T4 oncofoetal leucine-rich glycoprotein genes and expression in foetal and adult murine tissues.

The human 5T4 oncotrophoblast leucine-rich glycoprotein may contribute to the process of placentation or metastasis by modulating cell adhesion, shape and motility. To understand better the role of 5T4 in development and cancer, the gene structure has been elucidated from both human and mouse genomic clones and mRNA expression has been studied in foetal and adult mouse tissues. The protein coding region is located within the second of two exons, the first exon comprising solely of 5'-untranslated region. Upstream there are no TATA or CAAT boxes, but there are a number of potential Sp1 binding sites. The murine and human proteins show a homologous domain organisation of the leucine rich repeats (LRR) and associated N- and C-terminal flanking regions, although the hydrophilic sequence which intervenes between the two LRR domains contains six additional amino acids in the mouse. The signal peptide, transmembrane region and cytoplasmic tail sequences are identical as are 6 out of the 7 potential N-linked glycosylation sites. Mouse 5T4 transcripts are abundant in placenta and also highly expressed in embryos while in adult tissues transcripts are restricted to brain and ovary. These patterns of expression and the genomic organisation are discussed in relation to possible function and other recently described LRR containing proteins.

A temporal analysis of the effects of pressurized oxygen (HBO) on the pH of amputated muscle tissue.

The effect of hyperbaric oxygen (HBO) on ischemic muscle tissue pH was evaluated continuously. The hind limbs of male Sprague-Dawley rats (N=11, both groups) were amputated and stored in room air (20.1% oxygen [O2], 1.0 ATM, 24 degrees C) or in HBO (100% O2, 2.9 ATM, 24 degrees C) for 240 minutes. Rat muscle tissue pH was continuously monitored with a micro-pH electrode following amputation. There was no significant difference between the average starting tissue pH of control and treated limbs (p=0.45). At 240 minutes of ischemia the control group tissue pH decreased 0.80 pH units whereas the treatment group decreased 0.68 pH units (p < 0.05). The tissue pH of control limbs declined 30.7 times faster than treated limbs during the first 36 minutes of ischemia (p < 0.05). From 36 to 240 minutes the rates of acidosis were similar and did not differ significantly (p=0.46). In a separate study, male Sprague-Dawley rats were anesthetized with pentobarbital and ketamine. Aortic arterial blood gases were obtained at 5 minutes (N=8) and 15 minutes (N=8) postanesthesia. The average serum pH, carbon dioxide, oxygen, and bicarbonate levels remained within normal limits in both groups and did not differ significantly (p > 0.05 for all parameters). Anesthesia produced no serum respiratory or metabolic acidosis and did not contribute to the initial ischemic tissue pH. These results suggest that HBO delays the progression of metabolic acidosis in this amputated limb model. This is further supporting evidence for the tissue-preserving effect of oxygen when delivered in hyperbaric conditions. However, the clinical application of this technique may be limited due to the difference in the volume of tissue presented for major limb replantation and the short window of beneficial effects.

Flow cytometric analysis of chlorhexidine action.

The mechanism by which chlorhexidine kills bacteria is still ill defined. We have investigated the action of chlorhexidine on Escherichia coli JM101/psb311 using a combination of flow cytometry and traditional methods. Chlorhexidine-induced uptake by E. coli cells of bis-(1,3-dibutylbarturic acid) trimethine oxonol and propidium iodide, which monitor membrane potential and membrane integrity respectively, was shown to be concentration dependent for the range 0.003-0.3 mmol-1. In addition, cells in log phase growth were more susceptible to 0.03 mmol-1 chlorhexidine than those in stationary phase. There was, however, no direct correlation between dye uptake and decline in colony forming units.

Detection of occult gallbladder disease by duodenal drainage collected endoscopically. A clinical and pathologic correlation.

The bile of 100 patients with abdominal pain (suspected of having gallbladder disease) was collected from the duodenum at the time of esophagogastroduodenoscopy and examined for cholesterol and calcium bilirubinate crystals. Sixty of these patients had both negative oral cholecystograms and negative gallbladder sonograms, as well as no other objective evidence of gallbladder pathology. These patients are the subject of this report. Thirty-eight per cent of the 60 patients demonstrated crystals in bile collected at the time of endoscopy. None of the patients treated medically showed any improvement. Eight of the patients (35%) underwent cholecystectomy with 75 per cent of the gallbladders showing histologic pathology, and the remainder showing no pathology. However, all patients undergoing surgery who responded to a questionnaire improved whether or not pathology was found in the gallbladder. In contradistinction, of the patients undergoing surgery in whom no crystals were seen in the bile collected from the duodenum, pathology was found in only one third of the gallbladders and these patients' symptoms improved with surgery. Two thirds of the remaining patients had no pathologic changes in their gallbladder and only 50 per cent of these patients showed any improvement following surgery. However, patients who did not have crystals in their bile and were treated without surgery had a 58 per cent improvement rate with medical treatment alone. Duodenal drainage collected at the time of endoscopy and examination of the bile for cholesterol and bilirubinate crystals is a valuable adjunct in predicting which patients will respond favorably to cholecystectomy when there is no radiographic evidence of gallbladder disease.

Home health care for the elderly.

Home health services must be expanded and must include ongoing social work services. In addition to the provision of direct service, social workers are encouraged to advocate for quality home health services, to develop effective techniques for providing social services to home-care patients, to incorporate these techniques into social work education, and to become involved in the education of their medical colleagues. In this way, the home health field can begin to fulfill its goals by providing patients with quality care in the home setting, thus allowing them to remain independent and at the same time meeting their health and social needs.