Peri-operative ventricular bigeminy and cardiomyopathy in elective surgery

Premature ventricular contractions are common in the general population and are often seen during general anaesthesia. A high frequency of premature ventricular contractions may be associated with underlying left ventricular dysfunction. Premature ventricular contraction-induced cardiomyopathy is a rare disease and requires cardiologist input into peri-operative management. Medical and interventional management strategies may completely reverse the disease process. A 19-year-old man was scheduled for removal of tibial metalwork, due to chronic pain, and ventricular bigeminy was noted in the anaesthetic room before induction of anaesthesia. Surgery was postponed and he was later diagnosed with premature ventricular contraction-induced cardiomyopathy. Ventricular bigeminy noted before induction of anaesthesia may not always be benign.

Psychiatric Referrals within the Hospital – the Communication Process

This two part study examined the written communication between psychiatrists and other hospital doctors. In the first part a set of sample letters from a psychiatrist, who had seen a ward referral, was sent to 110 physicians and surgeons. Nearly half expressed a preference for a psychiatrist's letter that was one page long with main points underlined. Clarity of psychiatric diagnosis and opinion and clear treatment/follow-up arrangements were the key items of content. In the second part 100 consecutive referral letters and their replies were assessed; 20% of referral letters did not express the precise reason why psychiatric opinion was sought and many of the psychiatrists' replies did not describe adequately the follow-up arrangements and prognosis. In general the psychiatrist found the referral letters short and lacking in information whereas referring doctors found the brief replies from the psychiatrists preferable because the brief letters contained the key items mentioned in the first part of the study. In addition to these recommendations regarding written communications, this study emphasizes the need for personal discussion between psychiatrists and other hospital doctors; nearly half the doctors in the first part of the study thought this would be essential for good management of the patient.

Sensitive test for sea mine identification based on polarization-aided image processing

Techniques are widely sought to detect and identify sea mines. This issue is characterized by complicated mine shapes and underwater light propagation dependencies. In a preliminary study we use a preprocessing step for denoising underwater images before applying the algorithm for mine detection. Once a mine is detected, the protocol for identifying it is activated. Among many correlation filters, we have focused our attention on the asymmetric segmented phase-only filter for quantifying the recognition rate because it allows us to significantly increase the number of reference images in the fabrication of this filter. Yet they are not entirely satisfactory in terms of recognition rate and the obtained images revealed to be of low quality. In this report, we propose a way to improve upon this preliminary study by using a single wavelength polarimetric camera in order to denoise the images. This permits us to enhance images and improve depth visibility. We present illustrative results using in situ polarization imaging of a target through a milk-water mixture and demonstrate that our challenging objective of increasing the detection rate and decreasing the false alarm rate has been achieved.

Exploring underwater target detection by imaging polarimetry and correlation techniques

Underwater target detection is investigated by combining active polarization imaging and optical correlation-based approaches. Experiments were conducted in a glass tank filled with tap water with diluted milk or seawater and containing targets of arbitrary polarimetric responses. We found that target estimation obtained by imaging with two orthogonal polarization states always improves detection performances when correlation is used as detection criterion. This experimental study illustrates the potential of polarization imaging for underwater target detection and opens interesting perspectives for the development of underwater imaging systems.

Spectral optimized asymmetric segmented phase-only correlation filter

We suggest a new type of optimized composite filter, i.e., the asymmetric segmented phase-only filter (ASPOF), for improving the effectiveness of a VanderLugt correlator (VLC) when used for face identification. Basically, it consists in merging several reference images after application of a specific spectral optimization method. After segmentation of the spectral filter plane to several areas, each area is assigned to a single winner reference according to a new optimized criterion. The point of the paper is to show that this method offers a significant performance improvement on standard composite filters for face identification. We first briefly revisit composite filters [adapted, phase-only, inverse, compromise optimal, segmented, minimum average correlation energy, optimal trade-off maximum average correlation, and amplitude-modulated phase-only (AMPOF)], which are tools of choice for face recognition based on correlation techniques, and compare their performances with those of the ASPOF. We illustrate some of the drawbacks of current filters for several binary and grayscale image identifications. Next, we describe the optimization steps and introduce the ASPOF that can overcome these technical issues to improve the quality and the reliability of the correlation-based decision. We derive performance measures, i.e., PCE values and receiver operating characteristic curves, to confirm consistency of the results. We numerically find that this filter increases the recognition rate and decreases the false alarm rate. The results show that the discrimination of the ASPOF is comparable to that of the AMPOF, but the ASPOF is more robust than the trade-off maximum average correlation height against rotation and various types of noise sources. Our method has several features that make it amenable to experimental implementation using a VLC.

[Cancer patient's satisfaction assessment using the EORTC QLQ-SAT32: comparison between self-assessment and interview response]

BACKGROUND

For pertinent investigation of patient satisfaction it is important to know what type of data collection procedure yields optimal results. In this study, we compared a self- versus interview administration of the European Organisation for Research and Treatment of Cancer (EORTC) patient satisfaction questionnaire (QLQ-SAT32), noting response and item omission rates. We also assessed the correlation and agreement between responses according to these modalities of questionnaire administration.

METHODS

123 patients recruited in two anti-cancer Centers in France were asked to complete the QLQ-SAT32 at home within 2 weeks of hospital discharge and were randomly allocated to participate in a telephone interview-administration of the QLQ-SAT32, either before or after self-completing the QLQ-SAT32.

RESULTS

104 patients completed both modalities of questionnaire administration. Agreement proved excellent for the doctors' and nurses' subscales and satisfactory for the services' subscale and the general satisfaction single item. However, a significant difference in response rate showed up between Centers (different interviewers) and the interview modality revealed an item omission rate higher than for the self-administration modality.

CONCLUSION

Self- and interview-administration of the QLQ-SAT32 provided similar responses however different response rate between interviewers and higher item omission rate in interviews suggests a biasing effect of that modality of data collection.

A combination of lidocaine and nitrous oxide in oxygen is more effective in preventing pain on propofol injection than either treatment alone

BACKGROUND AND OBJECTIVE

Propofol is an intravenous (i.v.) anaesthetic agent that possesses many of the qualities of an ideal anaesthetic agent. The most significant side-effect associated with propofol is pain on injection. Despite optimal therapy, the incidence of pain on propofol injection remains a problem. This prospective, randomized, double blinded study evaluated the effect of three different treatment strategies in decreasing pain on propofol injection.

METHODS

We studied 102 adult, ASA I-II patients, scheduled for elective surgical procedures. Combination of i.v. lidocaine and nitrous oxide (N2O) in oxygen (O2) inhalation pre-treatment was compared with either treatment alone in the prevention of pain on propofol injection. A standard propofol injection technique and scoring system, to measure the pain on injection was used.

RESULTS

Demographic variables were similar between the groups. The incidence of no pain on propofol injection was similar in the lidocaine and N2O groups (63.6% vs. 57.5%) (95% confidence interval (CI): 0.17-0.29, P = 0.61). Combination therapy was associated with a greater incidence of no pain on injection (84% vs. 63.6%) (95% CI: 0.06-0.48, P = 0.04).

CONCLUSION

Combination of i.v. lidocaine and N2O in O2 inhalation pre-treatment is more effective than either treatment alone in decreasing pain on propofol injection.

In vitro demonstration of a mitogenic activity in renal tissue extracts during regenerative hyperplasia

Normal rat kidney (NRK-52E) cells, an established cell line of renal origin, were used as a bioassay system to reveal a possible mitogenic activity in tissue extracts prepared from kidneys undergoing tubular regeneration. Acute tubular injury was induced in female Wistar rats by a 4-day treatment with gentamicin at daily doses of 50 or 100 mg/kg twice daily. Animals were killed either 1 or 4 days after cessation of gentamicin administration. Proximal tubule regeneration in treated animals was confirmed by morphological examination after proliferating cell nuclear antigen staining. Tissue extracts from regenerating kidneys stimulated DNA synthesis in growth-arrested cells to a higher extent than extracts from intact kidneys. Sera from treated and control animals showed no difference with respect to mitogenic activity. The mitogenic effect of tissue extracts was sensitive to the tyrosine kinase inhibitor tyrphostin A46. The cell proliferative response to regenerating kidney extracts, but not that to intact kidney extracts, was partly suppressed by the addition of anti-insulin-like growth factor I (anti-IGF-I) antiserum. These data indicate that nephrogenic repair entails an elevation of biologically active IGF-I in kidney tissue.

Modification of immunoreactive EGF and EGF receptor after acute tubular necrosis induced by tobramycin or cisplatin

Acute tubular necrosis induced by aminoglycoside antibiotics and various other nephrotoxins is followed by a regenerative process which leads to the restoration of damaged tubules. Several lines of evidence indicate that tubular regeneration is mediated by polypeptide growth factors such as epidermal growth factor (EGF). Previous studies devoted to cisplatin nephrotoxicity have shown that this agent causes tubular cystic degeneration possibly related to an impairment of renal tissue repair. Thus, we examined on a comparative basis the time course of the regenerative response subsequent to tubular damage induced by tobramycin or cisplatin, particular attention being paid to renal EGF and its receptor. Female Sprague-Dawley rats (160-180 g body weight) were treated during 4 consecutive days with daily doses of 200 mg/kg tobramycin i.p. (BID) or 2 mg/kg cisplatin (once a day). Sham-treated rats were given 0.9% NaCl i.p. following the same protocol. Groups of experimental animals (n = 5-10) were terminated at increasing time intervals (1, 4, 7, 14, 21, 60 days) after cessation of treatment. One hour prior to sacrifice, each individual received i.p. 200 mg/kg 5-bromo-2'-deoxyuridine (BrdU) for the immunohistochemical demonstration of cell proliferation. Blood was collected at the time of sacrifice in order to assess glomerular filtration rate by measuring serum creatinine and BUN levels. Kidneys were analyzed with respect to total EGF determined by RIA in renal tissue homogenates, and soluble EGF was assayed in extracts prepared by centrifugation. Renal tissue was processed for the immunohistochemical detection of S-phase cells, of EGF, of EGF receptors, and of the intermediate filament vimentin, the latter being used as a marker of epithelium dedifferentiation. In absence of nephrotoxic alterations, EGF was immunolocalized in distal tubules, whereas EGF receptor immunostaining was seen in proximal tubules cells. Vimentin immunostaining was confined to glomeruli and blood vessels. Tobramycin and cisplatin caused acute tubular necrosis in proximal convoluted tubules and proximal straight tubules, respectively. Tissue damage was accompanied by renal dysfunction reflected by an elevation of serum creatinine and BUN levels. Tubular necrosis was followed by a proliferative response indicative of tubular regeneration. Regenerative hyperplasia was associated with a reduction of total immunoreactive EGF due to a decrease of tissue-bound proEGF. Tubules undergoing regenerative repair were characterized by a disappearance of EGF receptors and the presence of immunoreactive vimentin. In tobramycin-treated rats, renal dysfunction lasted for 4-7 days and was fully reversible, as indicated by the return of serum markers to normal values.

Five-hour oral glucose tolerance test in obese children

Concentrations of blood glucose, plasma free fatty acids, and plasma glycerol during a 5-hour oral glucose tolerance test on 46 obese children are reported. Seven children had unequivocally impaired glucose tolerance. However in the group as a whole, there was a delay in return of blood glucose to baseline levels after oral glucose, 27 children (60%) having a blood glucose concentration greater than 110 mg/100 ml at 2 hours. It was concluded that some degree of glucose intolerance is common in childhood obesity. No relation was seen among the following: impairment of glucose tolerance and age, degree or duration of obesity, or family history of diabetes. Fasting plasma free fatty acids and glycerol concentrations were high (mean ± 1SD, 1030 ± 221 μEq/litre FFA and 121 ± 44 μmol/l. glycerol). For all children, concentrations of FFA and glycerol decreased during the first hour after glucose, though minimal levels were not reached until 90-120 minutes (mean ± 1SD, 395 ± 170 μEq/litre FFA, 77 ± 24 μmol/l. glycerol). For those children (27) who had raised blood glucose at 2 hours, there was a positive correlation between fasting plasma glycerol concentration and glucose tolerance sum, suggesting that impaired glucose tolerance was associated with increased basal lipolysis.