Deep-learning-based, computer-aided classifier developed with a small dataset of clinical images surpasses board-certified dermatologists in skin tumour diagnosis

BACKGROUND

Application of deep-learning technology to skin cancer classification can potentially improve the sensitivity and specificity of skin cancer screening, but the number of training images required for such a system is thought to be extremely large.

OBJECTIVES

To determine whether deep-learning technology could be used to develop an efficient skin cancer classification system with a relatively small dataset of clinical images.

METHODS

A deep convolutional neural network (DCNN) was trained using a dataset of 4867 clinical images obtained from 1842 patients diagnosed with skin tumours at the University of Tsukuba Hospital from 2003 to 2016. The images consisted of 14 diagnoses, including both malignant and benign conditions. Its performance was tested against 13 board-certified dermatologists and nine dermatology trainees.

RESULTS

The overall classification accuracy of the trained DCNN was 76·5%. The DCNN achieved 96·3% sensitivity (correctly classified malignant as malignant) and 89·5% specificity (correctly classified benign as benign). Although the accuracy of malignant or benign classification by the board-certified dermatologists was statistically higher than that of the dermatology trainees (85·3% ± 3·7% and 74·4% ± 6·8%, P < 0·01), the DCNN achieved even greater accuracy, as high as 92·4% ± 2·1% (P < 0·001).

CONCLUSIONS

We have developed an efficient skin tumour classifier using a DCNN trained on a relatively small dataset. The DCNN classified images of skin tumours more accurately than board-certified dermatologists. Collectively, the current system may have capabilities for screening purposes in general medical practice, particularly because it requires only a single clinical image for classification.

Outcomes of patients receiving a massive transfusion for major trauma

BACKGROUND

The benefits of high transfusion ratios (plasma to red blood cells and platelets to red blood cells) on survival in injured patients who receive massive transfusions remain uncertain. This study aimed to assess the association between transfusion ratios and adverse events and survival in patients undergoing massive transfusion for major trauma.

METHODS

A retrospective observational study was conducted on patients who had major trauma using a Japanese national administrative database. The associations between transfusion ratios and outcomes (in-hospital mortality and incidence of adverse events) were analysed using a non-linear logistic generalized additive model (GAM). In a logistic generalized estimating equation model, adjusted for patient and hospital-level confounders, transfusion ratios were included as continuous or categorical variables (low, transfusion ratio 0·75 or less; intermediate, over 0·75 to 1·25; high, over 1·25).

RESULTS

Some 1777 patients were included in the analysis, of whom 602 died in hospital. GAM plots of the transfusion ratios for in-hospital mortality demonstrated a downward convex unimodal curve. In-hospital mortality was similar with increasing transfusion ratios for plasma (adjusted odds ratio (OR) 1·13, 95 per cent c.i. 0·82 to 1·55; P = 0·446) and platelets (adjusted OR 0·84, 0·66 to 1·08; P = 0·171). Both plasma to red blood cell ratio (adjusted OR 1·77, 1·32 to 2·37; P < 0·001) and platelet to red blood cell ratio (adjusted OR 1·71, 1·35 to 2·15; P < 0·001) were significantly associated with a higher incidence of adverse events. No significant differences in in-hospital mortality were observed between the three transfusion categories (low, medium and high).

CONCLUSION

In this study, transfusion strategies with high plasma to red blood cell and platelet to red blood cell ratios did not have survival benefits, but were associated with an increase in adverse events.

Effectiveness of early administration of tranexamic acid in patients with severe trauma

BACKGROUND

A reduction in mortality with the early use of tranexamic acid has been demonstrated in severely injured patients who are bleeding. However, the modest treatment effect with no reduction in blood transfusion has raised concerns. The aim of the present study was to estimate the effectiveness of regular use of tranexamic acid in severely injured patients.

METHODS

This multicentre observational study used retrospectively collected data from consecutive injured patients (Injury Severity Score at least 16) treated in 15 Japanese academic institutions in 2012. A propensity score-matched analysis compared patients who did or did not receive tranexamic acid administration within 3 h of injury. Study outcomes included 28-day all-cause and cause-specific mortality, and need for blood transfusion.

RESULTS

Of 796 eligible subjects, 281 were treated with tranexamic acid. Propensity score matching selected a total of 500 matched subjects (250 in each group). Tranexamic acid administration was associated with lower 28-day mortality (10·0 versus 18·4 per cent; difference -8·4 (95 per cent c.i. -14·5 to -2·3) per cent) and lower 28-day mortality from primary brain injury (6·0 versus 13·2 per cent; difference -7·2 (-12·3 to -2·1) per cent). However, there was no significant difference between groups in the need for blood transfusion (33·2 versus 34·8 per cent; difference -1·6 (-9·9 to 6·7) per cent).

CONCLUSION

Early tranexamic acid use was associated with reduced mortality in severely injured patients, in particular those with a primary brain injury.

Roles of short-chain fatty acids receptors, GPR41 and GPR43 on colonic functions

Short chain fatty acids (SCFAs) are the major anions in the large intestine. They are produced by a bacterial fermentation of dietary fiber. SCFAs are known to have a variety of physiological and pathphysiological effects on intestine. However, the mechanisms by which intraluminal SCFAs are sensed are not known. In 2003, two orphan G protein coupled receptors (GPRs), GPR41 and GPR43, have been cloned and demonstrated to be receptors for SCFAs. Thus, we had attempted to make antibodies raised against GPR43 and GPR41 to elucidate the roles of SCFAs on colonic functions. We have also evaluated the effects of SCFAs on colonic motility to define the physiological roles on luminal SCFAs. In rat and human colon, GPR43 protein was detected by Western blot analysis in extracts of whole wall and separated mucosa, but not in muscle plus submucosa extract. By immunohistochemistry, GPR43 immunoreactivity was localized with enteroendocrine cells expressing peptide YY, whereas 5-HT immunoreactive enteroendocrine cells were not immunoreactive for GPR43. GPR41 immunoreactivity was also found in human colon. In functional studies, propionate and butyrate concentration-dependently (10 microM - 10 mM) induced phasic and tonic contractions in rat colonic circular muscle. The propionate-induced phasic contraction was attenuated by atropine, tetrodotoxin and the 5-HT(4) receptor antagonists SB204070. However, acetate did not induce phasic or tonic contractions. Propionate-induced responses were not observed in mucosal free preparations. The present results suggest that the SCFA-induced physiological effects on colonic functions might be attributable to the activation of SCFA receptors on epithelial cells in the colon.

Detection of Salmonella in Spent Hens and Eggs Associated with Foodborne Infections

About 16,000 spent hens from 23 farms in the northern area of Japan were purchased in 1996, 1997, 1998, and 1999 to isolate Salmonella in two poultry processing plants. Salmonella was detected in 12 of 23 farms (52.2%). In particular, the serotypes Enteritidis and Infantis were detected in four and three farms, respectively. The prevalence rates in the hens' ceca, immature eggs, and the yolk of mature eggs in oviducts were 14%, 7.2%, and 6.8%, respectively. A total of 23 serotypes were detected. The major serotypes of the strains were Enteritidis, Corvallis, Typhimurium, and Infantis, but most of the strains were untypable. In the same area during 1992 to 1996, Salmonella was detected in eggs associated with four outbreaks of Salmonella Enteritidis infection and one outbreak of Salmonella Infantis infection. The ratio of contamination was approximately 1%, and the level was estimated to be 93 MPN(most probable number)/100 g in one outbreak. In farms that produced the eggs associated with all of the five outbreaks of Salmonella, the serotype Enteritidis or Infantis was isolated from hens. Farms where Salmonella was not detected were not related to any of the outbreaks.

Salmonella prevalence and total microbial and spore populations in spices imported to Japan

A total of 259 samples of 40 types of spices were tested for Salmonella prevalence and total microbial and spore populations. Salmonella enterica serotypes Weltevreden and Senftenberg were isolated from a black- and red-pepper sample, respectively. Because Salmonella was not detected by the most-probable-number method, it indicated that at least one cell of the microorganism was present in 25 g of sample. The mean aerobic bacterial count was greater than 5.39 log CFU/g in turmeric, garam masala, curry powder, and paprika. The mean bacterial spore counts were greater than 4.33 log CFU/g in turmeric and curry powder. The mean aerobic bacterial count in the two Salmonella-isolated samples was 6.93 log CFU/g. These results indicate that spices can be a source of contamination in the products where they are used as ingredients, and methods to reduce the microbial load in spices should be used.

New diagnostic peritoneal lavage criteria for diagnosis of intestinal injury

BACKGROUND

Although diagnostic peritoneal lavage (DPL) is a well-established, reliably objective method of diagnosis of intraperitoneal injury, it is too sensitive to be used as an indicator for emergency celiotomy. Therefore, since the development of ultrasonography and advanced computed tomographic scanners, the role of DPL has been markedly reduced. Despite such remarkable advances, however, radiologic diagnosis of intestinal injury cannot always provide definitive results, and DPL may still be valuable in such instances. We have developed a new DPL criteria specifically designed to aid in the diagnosis of intestinal injury and have evaluated its effectiveness.

METHODS

From August 1988 to December 1995, we performed DPL in 250 patients with blunt abdominal trauma and analyzed the diagnostic accuracy of our new criteria. We used the standard quantitative white blood cell (WBC) criterion for detection of intestinal injury supplemented by a positive-negative borderline adjusted to WBC > or = red blood cell (RBC)/150, where RBC > or = 10 x 10(4)/mm3.

RESULTS

Our criteria had a diagnostic sensitivity of 96.6% and a specificity of 99.4% for intestinal injury after exclusion of 57 patients in whom DPL was performed within 3 hours or after 18 hours from the time of injury. In 133 patients with hemoperitoneum, emergency celiotomy was performed in only 48; the remaining 85 patients with negative DPL based on the WBC criterion avoided surgery, and conservative management resulted in no complications.

CONCLUSION

With the proposed criteria, DPL can be used to diagnose or exclude intestinal injury even in the presence of hemoperitoneum.

[Is tacrolimus effective for ongoing renal allograft rejection?]

Tacrolimus has already gained a high reputation as an induction-maintenance immunosuppressive therapy after kidney transplantation. Recently, it is being used as rescue therapy against rejection, and its effectiveness also appears to have been established to some extent. In this study, we evaluated the efficacy of Tacrolimus rescue therapy at 4 institutions in the Kinki District. The subjects were 19 patients treated with Tacrolimus against rejection observed during immunosuppressive therapy using cyclosporin. Evaluation was made by classifying the patients into 6 with acute rejection that occurred within 3 months after transplantation (AR), 4 with late onset acute rejection that developed more than 3 months after operation (LAR), and 9 patients with chronic rejection (CR). In the AR group, many patients received combination therapy at the introduction of Tacrolimus, and the long-term outcome was satisfactory. Tacrolimus was effective in 2 (50%) of the 4 patients in the LAR group. The trough levels of Tacrolimus at its introduction were 10-15 ng/ml in the AR and LAR groups. Deterioration of the transplanted kidney function was prevented in 3 (50%) out of 6 patients in the CR group observed for less than 1 year, but it deteriorated in all 3 patients observed for 1 year or longer. The trough levels of tacrolimus at its introduction were 5-10 ng/ml in many patients in the CR group. The rescue therapy using Tacrolimus was effective against acute rejection but further follow-up is considered to be needed to evaluate its efficacy against chronic rejection.

Role of laparoscopic cholecystectomy in treating gallbladder polyps

Since the application of laparoscopic cholecystectomy (Lap C) to gallbladder polyps has not yet been fully evaluated, we performed Lap C on 26 patients with gallbladder polyps. Pathological examinations showed adenocarcinoma in three patients, adenoma in two, and cholesterol polyp in 21. Preoperative diagnoses of the cases with adenocarcinoma were a cholesterol polyp in one patient and an adenoma in two. Adenocarcinoma was confirmed to reside in the mucosa without any invasion of lymphatic ducts or small vessels in the three patients. This procedure was considered to be sufficient for this grade of cancer, and, therefore, no additional operations were performed. At present, our policy is to resect by Lap C a gallbladder polyp having a maximum size larger than 10 mm and a tendency to grow or presenting with suspicion of adenoma. When cancer is suspected by preoperative examinations, however, traditional surgery may be recommended.

[Production of leukotrienes in rat Kupffer cells and hepatocytes by various inducers]

In order to verify whether rat hepatocytes are capable of producing leukotrienes, Percoll density gradient centrifugation to fractionize rat hepatocytes and a radioimmunoassay of leukotrienes in the reacting solution have been performed. Also, investigated was effect of retinol (Vitamin A) on inducing the production of leukotrienes in rat Kupffer cells and hepatocytes. Incubation with endotoxin (10 micrograms/ml) for 30-60 minutes induced the production of leukotrienes in rat Kupffer cells but did not induce any such production in rat hepatocytes. On the other hand, arachidonic acid (2-20 microM) or linoleic acid (10-50 microns) did induce hepatocytes to produce leukotrienes in a dose-dependent manner. Fifteen minutes of pre-incubation with 10(-8) M of retinol inhibited an endotoxic induction of leukotrienes production in rat Kupffer cells, whereas it did not inhibit an arachidonic acid induction in rat hepatocytes. Based on these results, we have concluded that a hepatic tissue injury during sepsis is probably mediated by leukotrienes produced by the Kupffer cells and its inhibition is the mechanism of tissue protective effect of retinol. However, in further severe state even the hepatocytes may produce leukotrienes and as a consequence, a widespread destruction of hepatic tissue will occur.

Experimental transcatheter hepatic subsegmentectomy using absolute ethanol in dogs

In this study, we evaluate the effect of an intraportal injection of absolute ethanol in the canine liver and discuss how to introduce it in clinical application. The intraportal injection of ten milliliters of ethanol using a balloon occlusion catheter created an evident and well-demarcated necrotic lesion in the right central lobe. Histological examination showed a typical coagulation necrosis with fibrous bands, which became thicker day by day. The weight of the necroses ranged from 5 to 55 grams with an average of 26.0 +/- 5.5 grams (mean +/- SE), which was approximately 20 to 40 per cent of the right central lobe. Complications resulting from the ethanol injection were minimal and although more studies need to be done to clearly establish its safety for cirrhotic patients with hepatoma, this technique may be an easier and less invasive substitute for operative hepatic subsegmentectomy.

[Usefulness and problems of peritoneal tap & lavage on the diagnosis of blunt abdominal trauma--efficacy for diagnosis of intestinal injury]

It is difficult to diagnose blunt intestinal injury, despite of the progress of radiological diagnostic procedures, if patient has an altered mental status or an associated injury which hampers abdominal physical findings. So we conducted a prostective study about usefulness of peritoneal tap and lavage on the diagnosis of blunt abdominal injury. From September 1987 to August 1988 we performed peritoneal lavage in 36 patients and investigated the diagnostic accuracy of this method for detecting each organ injuries. We adopted conventional criteria "RBC greater than or equal to 100000/mm3, WBC greater than or equal to 500/mm3" and also employed new supplementary criteria "WBC greater than or equal to RBC/150 (if RBC/is positive), Amylase or Alkaline phosphatase greater than or equal to RBC/10000, GOT or GPT greater than or equal to RBC/40000". The diagnostic accuracy rates were 1) intestinal injury: WBC-sensitivdty (se) 75%, Specificity (sp) 100% 2) small intestinal injury; AMY-se 100%, sp 90%, Alp-se 100%, sp 100% 3) hepatic injury; GOT or GPT-se 100%, sp 91%. These satisfactory results can be obtained by employment of the new supplementary criteria. Peritoneal tap and lavage is easy to perform but is sometimes found to have poor fluid return. So we recommend to adopt the authentic method of peritoneal lavage. We concluded from this study that if these new supplementary criteria are employed peritoneal lavage can be useful to diagnose blunt intestinal injury.