Non-melanoma skin cancer diagnosis: a comparison between dermoscopic and smartphone images by unified visual and sonification deep learning algorithms.

PURPOSE: Non-melanoma skin cancer (NMSC) is the most frequent keratinocyte-origin skin tumor. It is confirmed that dermoscopy of NMSC confers a diagnostic advantage as compared to visual face-to-face assessment. COVID-19 restrictions diagnostics by telemedicine photos, which are analogous to visual inspection, displaced part of in-person visits. This study evaluated by a dual convolutional neural network (CNN) performance metrics in dermoscopic (DI) versus smartphone-captured images (SI) and tested if artificial intelligence narrows the proclaimed gap in diagnostic accuracy. METHODS: A CNN that receives a raw image and predicts malignancy, overlaid by a second independent CNN which processes a sonification (image-to-sound mapping) of the original image, were combined into a unified malignancy classifier. All images were histopathology-verified in a comparison between NMSC and benign skin lesions excised as suspected NMSCs. Study criteria outcomes were sensitivity and specificity for the unified output. RESULTS: Images acquired by DI (n = 132 NMSC, n = 33 benign) were compared to SI (n = 170 NMSC, n = 28 benign). DI and SI analysis metrics resulted in an area under the curve (AUC) of the receiver operator characteristic curve of 0.911 and 0.821, respectively. Accuracy was increased by DI (0.88; CI 81.9-92.4) as compared to SI (0.75; CI 68.1-80.6, p < 0.005). Sensitivity of DI was higher than SI (95.3%, CI 90.4-98.3 vs 75.3%, CI 68.1-81.6, p < 0.001), but not specificity (p = NS). CONCLUSION: Telemedicine use of smartphone images might result in a substantial decrease in diagnostic performance as compared to dermoscopy, which needs to be considered by both healthcare providers and patients.

Skin cancer detection by deep learning and sound analysis algorithms: A prospective clinical study of an elementary dermoscope.

BACKGROUND: Skin cancer (SC), especially melanoma, is a growing public health burden. Experimental studies have indicated a potential diagnostic role for deep learning (DL) algorithms in identifying SC at varying sensitivities. Previously, it was demonstrated that diagnostics by dermoscopy are improved by applying an additional sonification (data to sound waves conversion) layer on DL algorithms. The aim of the study was to determine the impact of image quality on accuracy of diagnosis by sonification employing a rudimentary skin magnifier with polarized light (SMP). METHODS: Dermoscopy images acquired by SMP were processed by a first deep learning algorithm and sonified. Audio output was further analyzed by a different secondary DL. Study criteria outcomes of SMP were specificity and sensitivity, which were further processed by a F2-score, i.e. applying a twice extra weight to sensitivity over positive predictive values. FINDINGS: Patients (n = 73) fulfilling inclusion criteria were referred to biopsy. SMP analysis metrics resulted in a receiver operator characteristic curve AUC's of 0.814 (95% CI, 0.798-0.831). SMP achieved a F2-score sensitivity of 91.7%, specificity of 41.8% and positive predictive value of 57.3%. Diagnosing the same set of patients' lesions by an advanced dermoscope resulted in a F2-score sensitivity of 89.5%, specificity of 57.8% and a positive predictive value of 59.9% (P=NS). INTERPRETATION: DL processing of dermoscopic images followed by sonification results in an accurate diagnostic output for SMP, implying that the quality of the dermoscope is not the major factor influencing DL diagnosis of skin cancer. Present system might assist all healthcare providers as a feasible computer-assisted detection system. FUND: Bostel Technologies. Trial Registration clinicaltrials.gov Identifier: NCT03362138.

Dermoscopy diagnosis of cancerous lesions utilizing dual deep learning algorithms via visual and audio (sonification) outputs: Laboratory and prospective observational studies.

BACKGROUND: Early diagnosis of skin cancer lesions by dermoscopy, the gold standard in dermatological imaging, calls for a diagnostic upscale. The aim of the study was to improve the accuracy of dermoscopic skin cancer diagnosis through use of novel deep learning (DL) algorithms. An additional sonification-derived diagnostic layer was added to the visual classification to increase sensitivity. METHODS: Two parallel studies were conducted: a laboratory retrospective study (LABS, n = 482 biopsies) and a non-interventional prospective observational study (OBS, n = 63 biopsies). A training data set of biopsy-verified reports, normal and cancerous skin lesions (n = 3954), were used to develop a DL classifier exploring visual features (System A). The outputs of the classifier were sonified, i.e. data conversion into sound (System B). Derived sound files were analyzed by a second machine learning classifier, either as raw audio (LABS, OBS) or following conversion into spectrograms (LABS) and by image analysis and human heuristics (OBS). The OBS criteria outcomes were System A specificity and System B sensitivity as raw sounds, spectrogram areas or heuristics. FINDINGS: LABS employed dermoscopies, half benign half malignant, and compared the accuracy of Systems A and B. System A algorithm resulted in a ROC AUC of 0.976 (95% CI, 0.965-0.987). Secondary machine learning analysis of raw sound, FFT and Spectrogram ROC curves resulted in AUC's of 0.931 (95% CI 0.881-0.981), 0.90 (95% CI 0.838-0.963) and 0.988 (CI 95% 0.973-1.001), respectively. OBS analysis of raw sound dermoscopies by the secondary machine learning resulted in a ROC AUC of 0.819 (95% CI, 0.7956 to 0.8406). OBS image analysis of AUC for spectrograms displayed a ROC AUC of 0.808 (CI 95% 0.6945 To 0.9208). By applying a heuristic analysis of Systems A and B a sensitivity of 86% and specificity of 91% were derived in the clinical study. INTERPRETATION: Adding a second stage of processing, which includes a deep learning algorithm of sonification and heuristic inspection with machine learning, significantly improves diagnostic accuracy. A combined two-stage system is expected to assist clinical decisions and de-escalate the current trend of over-diagnosis of skin cancer lesions as pathological. FUND: Bostel Technologies. Trial Registration clinicaltrials.gov Identifier: NCT03362138.

Transfection-capable polycationic nanovectors which include PEGylated-cyclodextrin structural units: a new synthesis pathway.

Efficient tools are still being searched for to substitute the viral vectors in nucleic acid delivery applications. One of the most severe constraints in producing them is related to the strict reproducibility of their molecular characteristics, which is ensured through the synthesis. In this work, we report an original route to obtain polycationic nanoentities with low variability, which are able to act as cooperating carriers for dsDNA complexation and transport. The carriers are synthesized by rigorous conjugation of ß-cyclodextrin (ß-CD) with precise ratios of 2 kDa branched poly(ethyleneimine) (b-PEI) and 0.75 kDa poly(ethylene glycol) (PEG). Low cytotoxicity was the key parameter of the carrier design, besides the highest possible transfection ability, and both of these features were proven by HeLa cell culture assays. A reporter gene which induces the expression of green fluorescent protein (GFP), inserted in a plasmid, was used to perform the necessary quantitative measurements. In silico molecular modelling guided the carrier design and confirmed the functional mimicry of histones in the tight and compact nucleosome-like spiral packaging of dsDNA. The carrier molecules, synthesized with high reproducibility, are expected to be feasible for application in gene transfection.

5 -year complex clinical and histopathological follow-up of a case of early gastric carcinoma (signet ring cells type).

The paper presents the case of a male patient, hospitalized for acute abdomen due to perforated callous ulcer. Though the clinical appearance suggested a benign pathology, the histopathological exam of the resection piece showed multicentric early gastric carcinoma, signet ring cell type. At the patient's request, total gastrectomy was not performed, a conservative solution being chosen instead. Superior digestive endoscopy with biopsy and oncological dispensarization was performed one month after surgery, then at every 6 months. After 2 years of benign results, the histopathological exam revealed the presence of malign singlet ring cells in the bioptic specimen. Respecting the patient's option of preserving a good quality of life, subtotal gastrectomy with Pean type gastroenteroanastomosis was performed followed by postoperatory chemotherapy. Endoscopic and oncological follow-up were performed at every six months for another 3 years (up to present), and the evolution was favorable with no local or metastatic recurrence. Histopathological examination was of great help in the surgical management of this case, allowing a fortunate early diagnosis, a conservative surgical approach, and the preserving of a good quality of life.

Laparoscopic cholecystectomy in patients aged 60 years and over - our experience.

Aim. To analyze the efficiency of laparoscopic cholecystectomy for the population aged 60 years and over admitted with acute cholecystitis, the clinical features and associated pathology presented by these patients and the impact of these factors on the choice of surgical technique. Materials and method. A retrospective study was carried out between February 2010 and February 2015, on patients aged 60 years and over, operated in emergency for acute cholecystitis in our clinic. All data were extracted from the registered medical documents and operatory protocols. Results. A total of 497 surgeries were performed for acute cholecystitis, of which 149 were patients aged 60 years and over (30%). Open surgery is much better represented in the population aged over 60 years (61.75% vs. 29.98%). One major cause is the associated pathology that increases the anesthetic risk and hampers a laparoscopic procedure. The conversion rate in the study group presented a higher percentage, but not more exaggerated than in the general population (6.71% vs. 4.63 %).Patients who underwent laparoscopic surgery had a faster recovery and required lower doses and shorter term pain medication, in contrast to conventional surgery (1,8 days vs. 5.7 days). Bile leak has been of reduced quantity, short-term and stopped spontaneously. Only one case needed reintervention, in which aberrant bile ducts that were clipped were found in the gallbladder bed, was operated by laparoscopy. Wound infections and swelling were also encountered more frequently in patients that underwent classic surgery (3.24%). Conclusions. Performing laparoscopic cholecystectomy, when possible, has produced very good results, reducing the average length of stay of patients and even decreasing the number of postoperative complications, thus allowing a faster reintegration of patients into society. The main concern was related to the associated pathology that increased the anesthetic risk.

Gastrostomy with peritoneal collar versus percutaneous endoscopic gastrostomy.

Aim. The present study aimed to perform a medico-surgical comparative analysis of the 2 most widely used techniques: gastrostomy with peritoneal collar versus percutaneous endoscopic gastrostomy, based on the vast clinical experience in an Upper Digestive Surgery Clinic. Materials and method. A retrospective study was carried out between January 2010 and January 2015 on the patients admitted for a surgical solution for feeding. The indications, preoperative preparation, surgical techniques, and postoperative outcomes were analyzed. Results. Out of the 94 cases admitted for a surgical solution for feeding, 67 underwent gastrostomy with peritoneal collar (GPC) and in 27 cases percutaneous endoscopic gastrostomy (PEG) was performed. The indications for GPC were benign or malign causes of dysphagia, the most frequent being malign tumors of tongue, pharynx and larynx (47.76%), advanced inoperable esophageal or eso-cardiac cancers (26,86%), post-caustic esophageal stenosis (10.44%). PEG was performed in patients with functional difficulties of swallowing: sequelae of cerebral vascular accidents (44.44%), low Glasgow Coma Scale Score (29.62%) of different etiologies, Parkinson disease (18.51%) advanced dementia (7.4%), early nasopharyngeal cancer (2 cases). The intraoperatory and postoperatory complications were few and of minor importance in both techniques, but PEG allowed an immediate retake of alimentation (vs. at least 48 hours wait in GPC), with less gastric stasis, biliary reflux and aspiration related respiratory problems. Conclusions. Both techniques are easy and safe to perform, but an appropriate selection is required according to the cause of the swallowing difficulty. In cases with permeable digestive tube, PEG may be an excellent minimally invasive solution, but the costs and availability of the PEG kit and prehydrolyzed nutritive solution, as well as the co-existence of an upper digestive endoscopy service were limitations that had to be taken into account.

Complex histopathological and surgical aspects in a case of giant malignant gastric perforation.

We present the case of a 52-year-old male patient, hospitalized on an emergency basis in the University Emergency Hospital in Bucharest, after being diagnosed with pneumoperitoneum acute abdomen, for which emergency surgery was mandatory. A 3,5-4 cm malignant gastric perforation, ascitis and peritoneal carcinomatosis were found. The histopathological exam revealed infiltrative mucinous gastric carcinoma with epiploic metastasis. Due to the lack of available gastric material, an atypical surgical solution was performed: gastric packing with epiploic material by means of transgastric traction. The solution proved to be successful for short-term recovery. The underlying condition was not focused on, the patient being directed to the Oncology Department. Acute gastric perforation is a rare complication of gastric cancer, and the association with gastric linitis is uncommon. This specific histopathological condition made the classical surgical repair techniques unsuitable for the presented case and an atypical solution had to be performed.

Inter-test reference height variability--a major error factor in Heidelberg Retina Tomography glaucoma progression analysis based on stereometric parameters changes.

PURPOSE: To investigate the role of reference height inter-test variability upon the variability of the stereometric parameters. MATERIALS AND METHOD: 204 glaucomatous patients underwent a complete ophthalmological exam, including Heidelberg Retina Tomography 3 (HRT-3). The exclusion criteria were optic disc or retinal pathology that might interfere with the detection of glaucoma progression, TSD >30µm. 4 sets of data were taken during the HRT-3 exam for each patient. RESULTS: RH variability ranged between -198 and 187. Correlation analysis revealed a linear dependence between the inter-test variability of RH and stereometric parameters change. The most powerful correlations were observed for: RNFL Thickness (r=0.756, p<0.001), Rim Area (r=0.662, p<0.001), C/D Area Ratio (r=-0.663, p<0.001). The least correlated were Height Variation Contour (r=0.31) and Cup Shape Measure (r=0.07, p=0.3). When RH variability did not exceed 25µm, the correlations with stereometric parameters change were not statistically significant (for Rim Area, r=0.21, p>0.05, for C/D Area Ratio, r=-0.13, p=0.22, for RNFL Thickness r=0.06, p=0.52). CONCLUSIONS: For values >25µm, the variability of the RH is a major factor determining test/retest variability for RNFL Thickness, Rim Area, C/D Area, Rim Volume and Linear C/D. Inter-test variability of RH <25µm is an important criterion for the clinical relevance of stereometric parameters changes.

Oesophageal stenosis dilatation through retrograde trans-gastrostomal approach in a patient with systemic scleroderma.

AIM: The paper presents the surgical solving of an oesophageal stenosis, using a device of pneumatic dilatation with trans-gastrostomal approach, in a patient with multiple disabling handicaps, secondary severe malnutrition and previously diagnosed with scleroderma. MATERIALS AND METHOD: The patient was admitted with severe cachexia (37 kg, 170 cm), characteristic byzantine face with microstomy, distal phalanges resorption in both superior limbs and complete dysphagia, with limitation of mouth opening.The Barium swallow test revealed distal oesophageal stenosis,with an important dilation of the oesophagus above. RESULTS: A gastrostoma was placed to allow nutrition (Gavriliu procedure), under general anaesthesia with trans-tracheostomal intubation. After 3 years, with her metabolic status improved(59 kg), the patient returned to our clinic asking for a solution for natural feeding. The technical difficulties in solving this case were determined by the limited mouth opening, which made anterograde oro-oesophageal balloon dilatation or bougienage impossible, as well as oro-tracheal intubation.Making use of the presence of the gastrostomal orifice,knowing von Hacker's mechanical dilation procedure and using the metallic Key Med kit with balls offered the possibility of the tactics and strategy of guiding a metallic guidewire introduced via the gastrostoma, then trans-stenotic and pulled out through the oral orifice. A modified Foley catheter (personal procedure) was attached to the initial catheter. The trans-stenotic retrograde traction of the Foley balloon was the pneumatic dilator factor that later allowed easy dilatation with the metallic dilator of the Key Med, to the maximum size. The follow-up showed good results, the patient returned to natural nutrition. CONCLUSIONS: The device of oesophageal pneumatic dilatation allows, using the presented surgical technique, a gentle plasty done under radiological supervision and lowers the frequency of accidents. The dilation permits the following use of Key Med kit. The novelty consists in adapting a well-known technique to a new patented device of pneumatic dilation with bidirectional approach under radiological control, for solving this atypical case.

Stereometric parameters change vs. Topographic Change Analysis (TCA) agreement in Heidelberg Retina Tomography III (HRT-3) early detection of clinical significant glaucoma progression.

PURPOSE: to investigate the sensitivity and specificity of the stereometric parameters change analysis vs. Topographic Change Analysis in early detection of glaucoma progression. METHODS: 81 patients with POAG were monitored for 4 years (GAT monthly, SAP at every 6 months, optic disc photographs and HRT3 yearly). The exclusion criteria were other optic disc or retinal pathology; topographic standard deviation (TSD>30; inter-test variation of reference height>25 µm. The criterion for structural progression was the following: at least 20 adjacent super-pixels with a clinically significant decrease in height (>5%). RESULTS: 16 patients of the total 81 presented structural progression on TCA. The most useful stereometric parameters for the early detection of glaucoma progression were the following: Rim Area change (sensitivity 100%, specificity 74.2% for a "cut-off " value of -0.05), C/D Area change (sensitivity 85.7%, specificity 71.5% for a "cut off " value of 0.02), C/D linear change (sensitivity 85.7%, specificity 71.5% for a "cut-off " value of 0.02), Rim Volume change (sensitivity 71.4%, specificity 88.8% for a "cut-off " value of -0.04). RNFL Thickness change (<0) was highly sensitive (82%), but less specific for glaucoma progression (45,2%). Changes of the other stereometric parameters have a limited diagnostic value for the early detection of glaucoma progression. CONCLUSION: TCA is a valuable tool for the assessment of the structural progression in glaucoma patients and its inter-test variability is low. On long-term, the quantitative analysis according to stereometric parameters change is also very important. The most relevant parameters to detect progression are RA, C/D Area, Linear C/D and RV.

Interleukin 6 and lipopolysaccharide binding protein - markers of inflammation in acute appendicitis.

The rate of incidence of acute appendicitis is 12% in the case of male patients and 25% in case of women, which represents about 7% of the world population. The appendectomy rate has remained constant (i.e. 10 out of 10,000 patients per year). Appendicitis most often occurs in patients aged between 11-40 years, on the threshold between the third and fourth decades, the average age being 31.3 years. Since the first appendectomy performed by Claudius Amyand (1681/6 -1740), on December, 6th, 1735 to our days, i.e., 270 years later, time has confirmed the efficiency of both the therapy method and the surgical solution. The surgical cure in case of acute appendicitis has proved to be acceptable within the most widely practised techniques in general surgery. The variety of clinical forms has reached all age ranges, which in its turn has resulted in a large number of semiotic signs. In the case of acute appendicitis, interdisciplinarity has allowed the transfer of concept and methodology transfer among many areas of expertise, aimed at a better, minute understanding of the inflammatory event itself. Acute appendicitis illustrates inflammation development at digestive level and provides for a diagnostic and paraclinical exploration which continually upgrades. The recent inclusion in the studies of the Lipopolysaccharide binding protein (LBP)- type inflammation markers has laid the foundation of the latter's documented presence in the case of acute appendicitis-related inflammation. Proof of the correlation between the histopathological, clinical and evolutive forms can be found by identifying and quantifying these inflammation markers. The importance of studying inflammation markers allows us to conduct studies going beyond the prognosis of the various stages in which these markers were identified. The present article shows the results of a 1-year monitoring of the inflammation markers' values for Interleukin-6 and Lipopolysaccharide binding protein (LBP)-types, both pre-op and 3-days post-op in the case of patients diagnosed with acute appendicitis in the Surgery Clinic IV of the Emergency University Hospital - Bucharest. The data collected have allowed us to correlate them with the selected parameters, and to draw the conclusions presented in this article.

Lipopolysaccharide binding protein (L.B.P.)--an inflammatory marker of prognosis in the acute appendicitis.

LIPOPOLYSACCHARIDE BINDING PROTEIN (LBP) is an important mediator of the inflammatory reaction. A multitude of factors can determine the genic transcription activation and the increase of the LBP in the blood and the human body humours: Il1, Il 6, lipopolysaccharides, Gram-negative bacteria, as well as non-infectious agents. This paper is a prospective study performed on 147 patients admitted for acute appendicitis in 2010-2012 and evaluates the dynamics of LBP in acute appendicitis, by identifying the correlations between the pre- and post-operatory levels of LBP (up to 72 hours after surgery) and the anatomopathological type (i.e. catarrhal, phlegmonous and gangrenous). The mean pre-op LBP values are significantly different as to the histopathological result (p<0,005). Among the biological inflammatory markers measured in this present study, LBP has a dynamics of its own in the catarrhal and phlegmonous appendicitis. Thus, if after the surgical removal of the infectious source, the leukocites and neutrophiles decrease 72 hrs after surgery, LBP continues an ascending curve. The importance of this study consists in the introduction of last generation LBP-type inflammatory markers' dosage in the cecal appendix pathology. This implementation is brand new in the Romanian surgical practice. The good correlation between the LBP pre-op values and the histopathological diagnosis of the appendicits form that we discovered during the present study opens the way to large-scale use of the biochemical dosage of LBP in the management of acute appendicitis.

[Clinical and morphological features in a case of recent gastric carcinoma (the signet ring cell carcinoma type)]. / Particularitati clinico-morfologice într-un caz de carcinom gastric incipient (tipul de carcinom în inel cu pecete).

The article presents the case of a male patient, hospitalized due to severe pain in the upper abdomen area, nausea, and vomiting. The patient was diagnosed with surgical acute abdomen, for which emergency surgery is performed. Upon penetration into the peritoneal cavity, stomach inspection shows at the medio-gastric level, on the greater curvature, a callous gastric ulcer, with a central perforation. A large excision is decided up to the healthy (normal) gastric tissue, and the resulting pieces are sent to the pathological anatomy laboratory. The histopathological exam reveals signet ring cell recent gastric carcinoma. The biopsy performed 1 month after surgery, prelevated from the antropyloric zone, reveals antropyloric gastritis with moderate activity and Helicobacter pylori positive. Due to the fact that such cases when this gastric cancer type is diagnosed in recent stages are extremely rare, we considered it useful to present it and look into its macroscopic and microscopic aspects, as well as into the differentiating diagnosis.

Confocal scanning laser ophthalmoscopy in glaucoma diagnosis and management.

The early diagnosis and detection of progression are two key-elements in the actual management of glaucoma. The current opinion in clinical practice is to quantify the structural damage for a better follow-up of the patient and the standardization of the results. The present review is a concise survey of literature covering the period of 1990-2010, documenting the evidence-based role of confocal scanning laser ophthalmoscopy in glaucoma diagnosis and management.

Heidelberg Retina Tomography analysis in optic disks with anatomic particularities.

Due to its objectivity, reproducibility and predictive value confirmed by many large-scale statistical clinical studies, Heidelberg Retina Tomography has become one of the most used computerized image analysis of the optic disc in glaucoma. It has been signaled, though, that the diagnostic value of Moorfieds Regression Analyses and Glaucoma Probability Score decreases when analyzing optic discs with extreme sizes. The number of false positive results increases in cases of megalopapillae and the number of false negative results increases in cases of small size optic discs. The present paper is a review of the aspects one should take into account when analyzing a HRT result of an optic disc with anatomic particularities.

[A rare cause of pneumoperitoneum]. / Pneumoperitoneu de cauza rara.

We provide the description of a 77 year old patient, admitted into the IC unit, with whom the surgical intervention was required by the presence of a massive pneumoperitoneum observed during abdominal CT. Anamnestic and clinical information was scarce; the patient had been admitted into the gastroenterology unit with the following diagnosis: acute pancreatitis, renal failure, atrioventricular block, while the hemodynamic instability made hospitalisation into the IC unit mandatory. Anatomopathological lesions secondary to a major vascular damage at the level of the celiac trunk and at the superior mesenteric level were noticed intraoperatively: total gastric necrosis with perforation, splenic infarction, entero-mesenteric infarction, abdominal wall necrosis. The patient did not allow for a surgical solution. The anatomopathological examination of the gastric tissue fragment enabled the diagnosis of extensive gangrene of the gastric wall. The relevance of the case consists in the presence of an abdominal vascular damage detected in full development, where the pneumoperitoneum required surgical exploration. The intricacy of the anatomopathological lesions accounts for the acute painful abdominal onset, accompanied by quick hemodynamic, clinical, and biochemical deterioration. Thus, gastric perforation through rupture secondary to total gastric gangrene of vascular origin joins the many causes of pneumoperitoneum.

A hyperosmotic stimulus elevates intracellular calcium and inhibits proliferation of a human keratinocyte cell line.

Occlusion has previously been used to treat psoriatic plaques and was shown to improve the condition. We investigated the consequences of applying a mechanical stress, in vitro, on the HaCaT keratinocyte cell line. A mechanical load applied to cells can be mimicked by a hyperosmotic stimulus. Exposure of HaCaT keratinocytes to different hyperosmotic solutions (final osmolarity in the range 350-600 mOsm, produced by sucrose addition) resulted in an inhibition of cell proliferation after 96 h of treatment. As keratinocyte maturation is regulated by calcium levels, we measured hyperosmotic-stimulus-induced changes of intracellular calcium ([Ca2+]i) by single-cell image analysis employing FURA-2/AM. The hyperosmotic stimulus produced a rapid transient 2.6-fold elevation of [Ca2+]i followed by a gradual decay to the basal level. The transients originated from extracellular as well as from intracellular calcium pools and did not respond to voltage-sensitive calcium channel blockers. The hyperosmotic stimulus was shown to increase the cellular expression of involucrin, a differentiation marker, following 72 h of incubation, as measured by flow cytometry. Treatment of cells with the [Ca2+]i chelator BAPTA/AM almost completely blocked the [Ca2+]i elevation, but did not alter cellular growth or the induction of differentiation observed after hyperosmotic stimulus. It is suggested that treatment of keratinocytes with hyperosmotic stimulus can induce short-time effects (calcium transients) as well as long-term cellular maturation.

Acoustic monitoring of intraoperative neuromuscular block.

Standard methods for accurate intraoperative measurement of neuromuscular block are either expensive or inconvenient and are not used widely. We have evaluated a new method of monitoring neuromuscular block using a low-frequency microphone. The method is based on the phenomenon of low-frequency sound emission by contracting skeletal muscle. Acoustic monitoring (MIC) with an air-coupled microphone was used to evaluate intraoperative neuromuscular block in 25 anaesthetized patients. The MIC recorded the response of the adductor pollicis muscle to supramaximal electrical stimulation of the ulnar nerve with train-of-four stimuli. The ratios of the first response (TI) to control (TC) were used for evaluation. Data obtained from the MIC were compared with simultaneous recordings, from the same hand, of mechanomyography (FDT), electromyography (EMG) and accelerography (ACC). Throughout the operative procedure, TI/TC ratios of the acoustic method correlated with the three reference devices: FDT, 12 patients, 262 data sets, r = 0.86, bias (%MIC-%FDT) = mean -5.3 (SD 19.6)%; EMG, 18 patients, 490 data sets, r = 0.85, bias (%MIC-%EMG) = -0.39 (20.29)%; and ACC, 13 patients, 328 data sets, r = 0.91, bias (%MIC-%ACC) = -3.0 (15.6)%. We conclude that monitoring intraoperative neuromuscular block by a microphone which transduces low-frequency muscle sounds is clinically feasible.

A hyperosmotic stimulus regulates intracellular pH, calcium, and S-100 protein levels in avian chondrocytes.

Cartilage is exposed to mechanical loads, generating at the level of single chondrocytes a hyperosmotic stimulus (HOS). The direct effect of HOS on second messenger pathways in avian chondrocytes was evaluated by fluorimetric and image analysis techniques. HOS caused an immediate intracellular acidification of 0.07 +/- 0.02 pH units (n = 7), followed by an initial pH recovery rate of 0.033 +/- 0.04 pH units/min towards the pre-stimulus baseline values. Concomitantly, the intracellular calcium ([Ca2+]i) responded with a transient rise from baseline value of 84.7 +/- 7.4 nM to peak level of 403.1 +/- 51.0 nM (n = 16, p < 0.001). The calcium response was abolished by two calmodulin inhibitors chlorpromazine and W-7. Since these inhibitors are known to be specific ligands of a S-100 protein, its intracellular staining was determined following HOS. The amount of immunodetectable S-100 protein was significantly increased following exposure to HOS (p < 0.05), and did not require an increase of [Ca2+]i. It appears that compression of cartilage is transduced into HOS of chondrocytes, and further elicits its effects through transient intracellular elevation of protons and calcium ions accompanied by increased staining of S-100 protein.