Visceral obesity and muscle mass determined by CT scan and surgical outcome in patients with advanced ovarian cancer. A retrospective cohort study.

OBJECTIVE: Visceral obesity (VO) is a risk factor for developing postoperative complications in patients undergoing abdominal oncological surgery. However, in ovarian cancer patients this influence of body composition on postoperative morbidity is not well established. The aim of this study is to assess the association between body composition and complications in patients with advanced ovarian cancer undergoing cytoreductive surgery. METHODS: Patients with FIGO stage 3 or 4 ovarian cancer between 2006 and 2017 were included. Visceral fat area, total skeletal mass and total fat area were measured on a single slice on the level of L3-L4 of the preoperative CT-scan. VO was defined as visceral fat ≥100cm2. The perioperative data were extracted retrospectively. A multivariate logistic regression analysis was performed to test the predictive value of multiple variables such as body composition, albumin levels and preoperative morbidity. RESULTS: 298 consecutive patients out of nine referring hospitals were included. VO patients were more likely to be hypertensive (38% vs 17% p < 0.001), and to have an ASA 3 score (21% vs 10% P = 0.012). Complications occurred more often in VO patients (43% vs 21% P < 0.001). Thrombotic events were found in 4.9% of VO patients versus 0.6% of the non-visceral obese patients (p = 0.019). VO(OR: 4.37, p < 0.001), hypertension (OR:1.9, p = 0.046) and duration of surgery (OR: 1.004, p = 0.017) were predictors of post-surgical complications. Muscle mass is not a predictor of complications. CONCLUSION: Visceral obesity is associated with a higher occurrence of complications in patients with advanced ovarian cancer undergoing cytoreductive surgery.

Reasons for (non)participation in supplemental population-based MRI breast screening for women with extremely dense breasts.

AIM: To determine the willingness of women with extremely dense breasts to undergo breast cancer screening with magnetic resonance imaging (MRI) in a research setting, and to examine reasons for women to participate or not. MATERIALS AND METHODS: Between 2011 and 2015, 8,061 women (50-75 years) were invited for supplemental MRI as part of the Dense Tissue and Early Breast Neoplasm Screening (DENSE) trial (ClinicalTrials.gov Identifier: NCT01315015), after a negative screening mammography in the national population-based mammography screening programme. Demographics of participants and non-participants were compared. All invitees were asked to report reasons for (non)participation. Ethical approval was obtained. Participants provided written informed consent. RESULTS: Of the 8,061 invitees, 66% answered that they were interested, and 59% eventually participated. Participants were on average 54-years old (interquartile range: 51-59 years), comparable to women with extremely dense breasts in the population-based screening programme (55 years). Women with higher socio-economic status (SES) were more often interested in participation than women with lower SES (68% versus 59%, p<0.001). The most frequently stated reasons for non-participation were "MRI-related inconveniences and/or self-reported contraindications to MRI" (27%) and "anxiety regarding the result of supplemental screening" (21%). "Expected personal health benefit" (68%) and "contribution to science" (43%) were the most frequent reasons for participation. CONCLUSION: Of women invited for MRI because of extremely dense breasts, 59% participated. Common reasons for non-participation were "MRI-related inconveniences" and "anxiety regarding the result of supplemental screening". In case of future implementation, availability of precise evidence on benefits and harms might reduce this anxiety.

Reducing contrast medium volume and tube voltage in CT angiography of the pulmonary artery.

AIM: To evaluate image quality after contrast medium (CM) and tube voltage reduction in computed tomography angiography (CTA) of the pulmonary artery. MATERIALS AND METHODS: Thirty-three patients referred for CTA of the pulmonary artery for suspected pulmonary embolism were included. Patients were randomly assigned to Protocol I (100 ml of 350 mg iodine/ml iodinated CM; n=16) or Protocol II (50 ml of 350 mg iodine/ml iodinated CM; n=17). Dual-energy CT (80 kV and 140 kV) was performed in all patients. An averaged weighted series equivalent to a 120 kV image acquisition was reconstructed. The mean attenuation value of CM was measured at eight positions in the pulmonary trunk and pulmonary arteries. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Qualitative assessment of the vascular enhancement was performed independently by two experienced radiologists using a three-point scale. Mean attenuation values, image noise, CNR, and SNR of images with 50 ml CM and images with 100 ml CM were compared and mean attenuation values, image noise, CNR, and SNR in 80 kV images and 120 kV images were compared. For qualitative analysis, interobserver variability was analysed using Cohen's kappa statistics. RESULTS: The mean attenuation values in Protocol I and Protocol II were not significantly different at 80 kV (634.6±168.3 versus 537.9±146.7 HU; p=0.088) and 120 kV (482.8±127.7 versus 410.4±106.0 HU; p=0.085). The mean attenuation value at 80 kV was significantly higher than the mean attenuation value at 120 kV in Protocols I and II (p<0.001). The CNR and SNR were higher at 120 kV than at 80 kV in both protocols (p=0.000-0.019); however, there were no significant differences in the CNR and SNR between both protocols (p=0.600-0.952). Qualitative (subjective) analysis showed no statistical significant difference between Protocols I and II (p=0.524-1.000). CONCLUSION: Low tube voltage (80 kV) CTA using 50 ml CM is not inferior to CTA at 120 kV using 100 ml CM.

A non-invasive cardiac output measurement as an alternative to the test bolus technique during CT angiography.

AIM: To investigate the association between a non-invasive cardiac output (CO) measurement and the scan delay, as derived from a test bolus injection protocol. The secondary objective was to determine which factors affect the relationship between the CO and scan delay. MATERIALS AND METHODS: Fifty-five patients referred for a contrast-enhanced (thorax-)abdomen CT examination were included in this feasibility study. A test bolus examination was performed prior to the abdominal CT. During the test bolus injection, the CO of the patient was measured using a non-invasive finger-cuff measurement. Associations were analysed using linear regression analyses. Age, gender, height, weight, and blood pressure were included as potential confounders. RESULTS: Linear regression analysis showed a negative and significant association between CO and delay. The regression formula was as follows: scan delay (seconds) = 26.8-1.6 CO (l/min), with a 95% CI between -2.3 and -1.0 (p<0.001). Weight appeared to be a confounder in this relation, and gender and blood pressure were effect modifiers. There was no interaction between scan delay and age, height and weight. CONCLUSIONS: There is a negative and significant association between the non-invasive CO measurement and the CT scan delay; however, to validate these findings a larger cohort study is needed to investigate whether the non-invasively determined scan delay is as accurate as the use of a test bolus.

Feasibility of a low concentration test bolus in CT angiography.

AIM: To investigate the feasibility of using a low-concentration test bolus in abdominal aorta computed tomography (CT) angiography (CTA). MATERIALS AND METHODS: In 10 patients referred for CTA of the abdominal aorta with a body mass index (BMI) ≤28 kg/m2, a standard test bolus of 10 ml contrast medium (CM; 350 mg iodine/ml) was compared with a low-concentration test bolus (5 ml CM; 350 mg iodine/ml; 1:1 diluted with saline) in terms of time to peak enhancement (tPE) and peak enhancement (PE). RESULTS: No significant differences were found between the standard and low-concentration test bolus in terms of tPE and PE. CONCLUSIONS: A low-concentration test bolus (5 ml, 1:1 diluted with saline) is feasible in patients with a BMI ≤28 kg/m2.

Low-dose CT angiography of the abdominal aorta and reduced contrast medium volume: Assessment of image quality and radiation dose.

AIM: To determine the effect of using 80 kV tube voltage and a reduced amount of contrast medium on the image quality and radiation dose of computed tomography angiography (CTA) of the abdominal aorta. MATERIALS AND METHODS: Patients who were referred for a CTA examination of the abdominal aorta were included in this technical efficacy study. Thirty patients were divided randomly into two groups. Fifteen patients underwent a dual-energy CT (DECT) protocol (Group A). Fifteen patients were scanned with the use of an automated tube potential selection algorithm tool (Group B). In both protocols, a test bolus injection of 10 ml ioversol (350 mg iodine/ml) was used, followed by 20 ml of 1:1 saline-diluted contrast medium. Quantitative analysis comprised determination of the mean attenuation and contrast-to-noise ratio. Qualitative image analysis was performed independently by five radiologists. The estimated radiation dose in terms of CT dose index and effective dose was recorded and compared with a standard 120 kV protocol. RESULTS: In Group B, six patients underwent CTA at 80 kV, seven patients underwent CTA at 100 kV and two patients underwent CTA at 120 kV. The mean contrast-enhancement values of Group A (80 kV) and the 80 kV subgroup of Group B were 16.5% and 27.6% higher compared to the 100 kV subgroup of Group B, these differences were, however, not significant. There were no significant differences in mean image quality between groups. In patients undergoing CTA at 80 kV the effective dose decreased by up to 51.3% compared to a conventional 120 kV CTA protocol. CONCLUSIONS: The findings of this study support the hypothesis that 80 kV in CTA of the abdominal aorta can reliably be used with only 30 ml contrast medium in total and a 50% reduction in radiation dose. The overall image quality was diagnostically adequate; however, it appeared to be suboptimal in patients with a BMI above 28 kg/m(2).

Development and internal validation of a prognostic model for survival after debulking surgery for epithelial ovarian cancer.

OBJECTIVE: Predicting survival of patients with epithelial ovarian cancer (EOC) is based on prognosis of the population. Combining prognostic factors could facilitate survival prediction on the level of the individual patient. The aim of this study was to develop a prognostic model to predict five-year disease specific survival in patients with EOC, and to evaluate whether this would add to prediction based on prognosis of the population. PATIENTS AND METHODS: A retrospective cohort study was performed of all EOC patients treated with primary debulking and adjuvant chemotherapy or neo-adjuvant chemotherapy and interval debulking surgery in three gynaecological-oncologic centres between 1998 and 2010. Primary outcome was 5-year disease-specific survival. We developed a Cox proportional hazard model using the LASSO-method to select the best combination of characteristics from 12 potential predictors and to correct for overfitting. Performance of the model was expressed as calibration and discrimination (c-statistic). A nomogram was developed to increase the clinical applicability of the model. RESULTS: Of 840 patients with EOC 462 (55%) died within 5 years due to the disease. A combination of FIGO stage, residual tumour after surgery, primary or interval surgery, histology, performance status, age, amount of ascites and a family history suggestive of breast/ovarian cancer best predicted 5-year survival. The final model showed accurate calibration and the c-statistic was 0.71 (95% CI 0.69-0.74). CONCLUSIONS: Five-year survival in all stage EOC patients can be predicted accurately using available characteristics. After external validation the model can be used for counselling of patients.

AI-support for the detection of intracranial large vessel occlusions: One-year prospective evaluation.

Purpose: Few studies have evaluated real-world performance of radiological AI-tools in clinical practice. Over one-year, we prospectively evaluated the use of AI software to support the detection of intracranial large vessel occlusions (LVO) on CT angiography (CTA). Method: Quantitative measures (user log-in attempts, AI standalone performance) and qualitative data (user surveys) were reviewed by a key-user group at three timepoints. A total of 491 CTA studies of 460 patients were included for analysis. Results: The overall accuracy of the AI-tool for LVO detection and localization was 87.6%, sensitivity 69.1% and specificity 91.2%. Out of 81 LVOs, 31 of 34 (91%) M1 occlusions were detected correctly, 19 of 38 (50%) M2 occlusions, and 6 of 9 (67%) ICA occlusions. The product was considered user-friendly. The diagnostic confidence of the users for LVO detection remained the same over the year. The last measured net promotor score was -56%. The use of the AI-tool fluctuated over the year with a declining trend. Conclusions: Our pragmatic approach of evaluating the AI-tool used in clinical practice, helped us to monitor the usage, to estimate the perceived added value by the users of the AI-tool, and to make an informed decision about the continuation of the use of the AI-tool.

Prediction of ß-lactoglobulin genotypes based on milk Fourier transform infrared spectra.

ß-Lactoglobulin (ß-LG) genotypes are associated with differences in bovine milk protein composition. Therefore, ß-LG genotypes are of direct relevance for the dairy industry. In this study, we predicted ß-lactoglobulin genotypes based on routinely recorded milk Fourier transform infrared spectra using 500 calibration samples. The results show that 76% of the cows carrying the ß-LG AA genotype, 80% of the cows carrying the ß-LG AB genotype, and 66% of the cows carrying the ß-LG BB genotype were predicted correctly. Furthermore, the prediction of ß-LG genotypes based on Fourier transform infrared spectra showed a repeatability of 0.85. We discuss how the combined use of predicted ß-LG genotypes, pedigree information, and ß-LG genotypes derived using other methods could lead to further improvement in the percentage of correctly predicted ß-LG genotypes. The presented methodology is easy and inexpensive and could ultimately provide ß-LG genotypes at the individual cow level.

Predicting bovine milk protein composition based on Fourier transform infrared spectra.

Phenotypic information on individual protein composition of cows is important for many aspects of dairy processing with cheese production as the center of gravity. However, measuring individual protein composition is expensive and time consuming. In this study, we investigated whether protein composition can be predicted based on inexpensive and routinely measured milk Fourier transform infrared (FTIR) spectra. Based on 900 calibration and 900 validation samples that had both capillary zone electrophoresis (CZE)-determined protein composition and FTIR spectra available, low to moderate validation R(2) were reached (from 0.18 for α(S1)-casein to 0.56 for ß-lactoglobulin). The potential usefulness of this model on the phenotypic level was investigated by means of achieved selection differentials for 25% of the best animals. For α-lactalbumin (R(2)=0.20), the selection differential amounted to 0.18 g/100g and for casein index (R(2)=0.50) to 1.24 g/100g. We concluded that predictions of protein composition were not accurate enough to enable selection of individual animals. However, for specific purposes when, for example, groups of animals that meet a certain threshold are to be selected, the presented model could be useful in practice on the phenotypic level. The potential usefulness of this model on the genetic level was investigated by means of genetic correlations between CZE-determined and FTIR-predicted protein composition traits. The genetic correlations ranged from 0.62 (ß-casein) to 0.97 (whey). Thus, predictions of protein composition, when used as input to estimate breeding values, provide an excellent means for genetic improvement of protein composition. In addition, estimated repeatabilities based on 3 repeated observations of predicted protein composition showed that a considerable amount of prediction error can be removed using repeated observations.

The effect of the number of observations used for Fourier transform infrared model calibration for bovine milk fat composition on the estimated genetic parameters of the predicted data.

Fourier transform infrared spectroscopy is a suitable method to determine bovine milk fat composition. However, the determination of fat composition by gas chromatography, required for calibration of the infrared prediction model, is expensive and labor intensive. It has recently been shown that the number of calibration samples is strongly related to the model's validation r(2) (i.e., accuracy of prediction). However, the effect of the number of calibration samples used, and therefore validation r(2), on the estimated genetic parameters of data predicted using the model needs to be established. To this end, 235 calibration data subsets of different sizes were sampled: n=100, n=250, n=500, and n=1,000 calibration samples. Subsequently, these data subsets were used to calibrate fat composition prediction models for 2 specific fatty acids: C16:0 and C18u (where u=unsaturated). Next, genetic parameters were estimated on predicted fat composition data for these fatty acids. Strong relationships between the number of calibration samples and validation r(2), as well as strong genetic correlations were found. However, the use of n=100 calibration samples resulted in a broad range of validation r(2) values and genetic correlations. Subsequent increases of the number of calibration samples resulted in narrowing patterns for validation r(2) as well as genetic correlations. The use of n=1,000 calibration samples resulted in estimated genetic correlations varying within a range of 0.10 around the average, which seems acceptable. Genetic analyses for the human health-related fatty acids C14:0, C16:0, and C18u, and the ratio of saturated fatty acids to unsaturated fatty acids showed that replacing observations on fat composition determined by gas chromatography by predictions based on infrared spectra reduced the potential genetic gain to 98, 86, 96, and 99% for the 4 fatty acid traits, respectively, in dairy breeding schemes where progeny testing is practiced. We conclude that a relatively large number of calibration samples is required to be able to obtain genetic correlations that lie within a limited range. Considering that the routine recording of infrared spectra is relatively cheap and straightforward, we concluded that this methodology provides an excellent means for the dairy industry to genetically alter milk fat composition.

Predicting bovine milk fat composition using infrared spectroscopy based on milk samples collected in winter and summer.

It has recently been shown that Fourier transform infrared spectroscopy has potential for the prediction of detailed milk fat composition, even based on a limited number of observations. Therefore, there seems to be an opportunity for improvement by means of using more observations. The objective of this study was to verify whether the use of more data would add to the accuracy of predicting milk fat composition. In addition, the effect of season on modeling was quantified because large differences in milk fat composition between winter and summer samples exist. We concluded that the use of 3,622 observations does increase predictability of milk fat composition based on infrared spectroscopy. However, for fatty acids with low concentrations, the use of many observations does not increase predictability to a level at which application of the model becomes obvious. Furthermore, the effect of season on validation r-square was limited but was occasionally large on prediction bias. For fatty acids that show large differences in level and standard deviation between winter and summer, a representative sample that includes observations collected in various seasons is critical for unbiased prediction. This research shows that all major fatty acids, combined groups of fatty acids, and the ratio of saturated to unsaturated fatty acids can be predicted accurately.

[Radio frequency ablation therapy in the elderly breast cancer patient]. / Radiofrequente ablatiebehandeling van de oudere patiënte met een mammacarcinoom.

Breast cancer is an important health care problem, especially in the increasing elderly generation. Treatment of these fragile patients is a challenge for the clinician. Undertreatment has been linked to a higher percentage of recurrence and cancer related morbidity, while overtreatment leads to treatment related morbidity and mortality. Minimally invasive techniques do offer new opportunities for patients, who are no candidates for conventional surgery. The tumor lesion is treated locally and selective with minimal damage to surrounding tissue, yielding an adequate local tumor control. Radio frequency ablation technique seems an effective and safe method for treatment of the elderly patient with small (< 3 cm) breast cancer.

[Dual-energy CT: new diagnostic possibilities]. / 'Dual-energy CT': nieuwe diagnostische mogelijkheden.

Dual-energy CT (DECT) provides more information than a conventional CT scan. This new technique does not only provide morphological information, but also provides information about the chemical composition of tissues and substances, e.g. uric acid or calcium, based on material-specific differences in X-ray attenuation, leading to diagnostic improvement. Other benefits include reduced radiation dose, reduced use of contrast fluids due to better iodine detection and improved image quality. DECT fulfils a need in patients with a hypersensitivity to contrast agents, leads to less kidney damage, and avoids the necessity of more invasive diagnostic methods such as lumbar punctures. There are clinical applications in the fields of cardiovascular and pulmonary medicine, urology and musculoskeletal diagnostics. For example, DECT can display monosodium urate depositions in a non-invasive manner, so that the effectiveness of gout treatment can be monitored. Kidney stones, coronary plaques and pulmonary emboli can also be displayed on the basis of their material-specific X-ray attenuation.

[Characterisation of breast lesions with VTIQ elastography: a new elastography method to evaluate the stiffness of tissues]. / Mammatumoren karakteriseren met VTIQ-elastografie.

B-mode ultrasound is used as an adjunct to mammography to differentiate between benign and malignant breast lesions. An additional ultrasound technique is elastography which can evaluate the stiffness of tissues. It is believed that malignant lesions are generally stiffer than benign lesions. Virtual touch tissue Quantification (VTIQ) is a new elastography method for measuring the stiffness of tissue. Because this method does not depend on the degree of compression, measurements are reliable and reproducible. VTIQ - in combination with ultrasonography - has the potential to characterise abnormalities in more detail. Adding elastography to regular B-mode ultrasound improves the diagnostic specificity without loss of sensitivity. This suggests that VTIQ might change patient management and avoid unnecessary biopsies. However, further research involving a greater variety of abnormalities and larger study populations is indicated.

Venous Thoracic Outlet Syndrome.

BACKGROUND: A 19-year-old woman, Academy of Sport student, noticed a progressive bluish discoloration, swelling and pain of the right hand and axilla during abduction. The symptoms had been progressive for 6 months. During physical examination there was a normal sensibility and motor function, and normal pulsations of the radial and ulnar artery. There was no significant medical history. A thorax aperture radiograph was performed, followed by venography of the right arm in neutral position and with abduction.

Electrical resistance and macromolecular permeability of brain endothelial monolayer cultures.

Electrophysiological measurements were made on endothelial cells initially isolated as individual clones from bovine brain microvessels, and then grown as monolayers on a permeable support of glutaraldehyde-treated collagen gel. When transendothelial cell resistance (R) of the clones was measured, there was a range of values from a low of 157.4 +/- 4.5 omega.cm2 (n = 6) to a high of 783.2 +/- 7.0 omega.cm2 (n = 34). With the high-resistance cells, there was also a small potential difference of -0.46 +/- 0.03 mV luminal-side negative (n = 34). In comparison, endothelial cells from bovine aortas and rat epididymal fat pads cultured on the collagen gels had transendothelial R values of 13.5 +/- 0.2 (n = 62) and 0.45 +/- 0.03 (n = 10) omega.cm2, respectively. Exposure of the high-resistance brain endothelial cell monolayers to a Ca2+-free medium for 10 min decreased the R to 75% of the control values. Addition of Ca2+ back to the medium caused a return of the transendothelial R to control values within 1 h. Endothelial cells were also grown to confluency on microcarrier beads for permeability measurements to Evans blue dye-bovine serum albumin. Microcarriers with no cells (control) and microcarriers with bovine and epididymal endothelial cell monolayers showed no difference in the amount of adsorbed dye. Microcarriers with brain endothelial monolayers excluded up to 80% of the dye. This mammalian brain endothelial culture system will be a useful model for studies of the electrophysiological and permeability properties of the blood-brain barrier.

Prolonged survival of adult rat pancreatic islets transfected with E1A-12S adenovirus.

It has been reported that various mutants of the E1A-adenovirus can activate quiescent differentiated cells to start proliferating. The aim of this study was to determine whether transfection with E1A-12S could extend the life span and functionality of pancreatic islets in culture. Rat pancreatic islets were isolated and transfected with retrovirus containing the adenovirus E1A-12S, E1A-13S, or control vectors. Transfection with the retroviral E1A-13S mutant produced extensive islet necrosis compared with nontransfected islets. Islets transfected with the control E1A mutant Ad5-dl312 vector (containing no E1A-12S or E1A-13S segments) were similar to nontransfected islets in their characteristics. We found that the E1A-12S transfected islets maintained greater viability, insulin granule structure, and glucose-induced insulin responsiveness over a 6-week period compared with mock or control islets. At 6 weeks of culture, the E1A-12S transfected islets also had fewer apoptotic cells compared with nontransfected islets. These data suggest that adenovirus E1A-12S can extend the functional life span of cultured rat pancreatic islets.

The benefit of STent placement and blood pressure and lipid-lowering for the prevention of progression of renal dysfunction caused by Atherosclerotic ostial stenosis of the Renal artery. The STAR-study: rationale and study design.

BACKGROUND: Atherosclerotic renal artery stenosis (ARAS) is associated with progressive loss of renal function and is one of the most important causes of renal failure in the elderly. Current treatment includes restoration of the renal arterial lumen by endovascular stent placement. However, this treatment only affects damage caused by ARAS due to the stenosis and ensuing post-stenotic ischemia. ARAS patients have severe general vascular disease. Atherosclerosis and hypertension can also damage the kidney parenchyma causing renal failure. Medical treatment focuses on the latter. Lipid-lowering drugs (statins) could reduce renal failure progression and could reduce the overall high cardiovascular risk. The additional effect on preserving renal function of stent placement as compared to medical therapy alone is unknown. Therefore, the STAR-study aims to compare the effects of renal artery stent placement together with medication vs. medication alone on renal function in ARAS patients. METHOD: Patients with an ARAS of > or = 50% and renal failure (creatinine (Cr) clearance < 80 mL/min/1.73 m2) are randomly assigned to stent placement with medication or to medication alone. Medication consists of statins, anti-hypertensive drugs and antiplatelet therapy. Patients are followed for 2 yrs with extended follow-up to 5 yrs. The primary outcome of this study is a reduction in Cr clearance > 20% compared to baseline. This trial will include 140 patients.

Rapid repair of injured gastric mucosa.

The morphology of the rat gastric mucosa superficially damaged by a 30-45 sec exposure to 100% ethanol caused over 99% of the luminal surface to be necrotic without extensive hemorrhage or hyperemia. However, this damaged area restituted or rapidly healed and the process was described. These findings were compared with in vitro gastric mucosae of bullfrogs and guinea pigs which were damaged with 1 or 1.25 M NaCl and allowed to restitute. The rat gastric mucosa showed evidence of cell migration within 5 min after ethanol damage and after 15 min as much as 50% of the denuded basement membrane was restituted. After 30 min about 75% of the mucosa was covered with cells and by 1 h there were only minor epithelial discontinuities. The in vitro frog mucosal restitution after hypertonic injury was slower and required 1-2 h to show appreciable cell migration and 4-6 h for completion of the repair process. Using chambered guinea pig gastric mucosa damaged with hypertonic NaCl restituted the necrotic surface almost as rapidly as the intact rat stomach necrotized with absolute ethanol. Since prostaglandin treatment did not prevent ethanol or hypertonic salt injury or affect the restitution process it was proposed that the term cytoprotection as it is generally used is not appropriate.