Clinical differentiation of infectious mononucleosis that is caused by Epstein-Barr virus or cytomegalovirus: A single-center case-control study in Japan

Introduction

Infectious mononucleosis (IM) is a common viral infection that typically causes fever, pharyngitis, and lymphadenopathy in young patients. The Epstein-Barr virus (EBV) is the most common cause of IM, followed by cytomegalovirus (CMV). Given that serological testing is associated with limitations regarding its accuracy, availability, and time to receive results, clinical differentiation based on symptoms, signs, and basic tests would be useful. We evaluated whether clinical findings could be used to differentiate EBV-IM from CMV-IM.

Methods

In this single-center retrospective case-control study, we evaluated >14-year-old patients with serologically confirmed EBV-IM or CMV-IM during 2006–2017. We compared the patients’ symptoms, physical findings, blood counts, and serum biomarkers to create three regression models: model 1 (symptoms and signs), model 2 (model 1 plus sonographic hepatosplenomegaly and blood counts), and model 3 (model 2 plus hepatobiliary biomarkers).

Results

Among the 122 patients (72.6%) with EBV-IM and 46 patients (27.4%) with CMV-IM, the median age was 25 years and 82 patients (48.8%) were male. The median age was 10 years older in the CMV-IM group (p < 0.001) and the median interval from onset to visit was 5 days longer in the CMV-IM group (p < 0.001). Logistic regression revealed that EBV-IM was predicted by younger age, short onset-to-visit interval, lymphadenopathy, tonsillar white coat, hepatosplenomegaly, atypical lymphocytosis, and elevations of lactate dehydrogenase and gamma-glutamyl transferase. All regression models had areas under the curve of >0.9.

Conclusion

History and physical findings, especially when used with atypical lymphocytosis and sonographic hepatosplenomegaly, can help physicians differentiate EBV-IM from CMV-IM.

Meningitis associated with strongyloidiasis in an area endemic for strongyloidiasis and human T-lymphotropic virus-1: a single-center experience in Japan between 1990 and 2010

Meningitis caused by enteric flora is a known complication of strongyloidiasis, and human T-lymphotropic virus-1 (HTLV-1) predisposes individuals to severe strongyloidiasis. We reviewed the clinical features of bacterial meningitis associated with strongyloidiasis seen at a single center in subtropical Japan, in an area endemic for both strongyloidiasis and HTLV-1. We found 33 episodes in 21 patients between 1990 and 2010. The results were remarkable for the high incidence of meningitis due to Gram-positive cocci (27.3 %), especially Streptococcus bovis, and culture-negative cases (42.4 %). Given the high incidence of Gram-positive meningitis, a modified approach to corticosteroid use would be advisable in areas where strongyloidiasis is endemic, due to the potentially adverse consequences of glucocorticoid therapy.

Carotid thromboembolism associated with nephrotic syndrome treated with dabigatran

Nephrotic syndrome (NS) may be complicated by thromboembolism, which occasionally manifests as stroke. Although the optimal, standardized approach to the prophylaxis and management of thromboembolic complications associated with NS has not been established, anticoagulation with heparin and subsequent warfarin is the de facto standard of treatment. Dabigatran, a novel direct thrombin inhibitor, has become a substitute for warfarin and heparin for many indications, including the prophylaxis of stroke associated with nonvalvular atrial fibrillation and postoperative thromboprophylaxis in orthopedic patients. We report a 35-year-old male with NS due to membranous nephropathy (MN) that presented with carotid thromboembolism. Because the patient developed drug-induced hepatitis due to warfarin, we attempted treatment with dabigatran and were successful in continuing the medication without any complications. We also reviewed the literature on stroke associated with NS. Twenty-one prior cases have been reported, and the review of these cases revealed some interesting points. The age of onset ranged from 19 to 59 years. Most of the reported cases sustained a stroke at earlier ages than patients with atherosclerosis and atrial fibrillation, which suggests that NS may independently predispose individuals to arterial and venous thromboses. MN was the most common underlying pathology. Given that a standardized approach to the prophylaxis and management of thrombotic complications associated with NS has not been established, our experience suggests that dabigatran is a valid new treatment option for thrombotic complications of NS.

Clinical prediction of complicated appendicitis: A case-control study utilizing logistic regression

BACKGROUND

Since high-quality evidence on conservative treatment of acute appendicitis using antibiotics has increased, differentiation of patients with complicated appendicitis (CA) from those with simple appendicitis (SA) has become increasingly important. Previous studies have revealed that male gender, advanced age, comorbid conditions, prehospital delay, fever, and anorexia are risk factors of perforated appendicitis. Elevated serum C-reactive protein (CRP) level and hyponatremia have also been reported as predictive biomarkers of CA. However, confounding between various factors is problematic because most previous studies were limited to univariate analysis.

AIM

To evaluate non-laboratory and laboratory predictive factors of CA using logistic regression analyses.

METHODS

We performed an exploratory, single-center, retrospective case-control study that evaluated 198 patients (83.9%) with SA and 38 patients (16.1%) with CA. Diagnoses were confirmed by computed tomography images for all cases. We compared age, sex, onset-to-visit interval, epigastric/periumbilical pain, right lower quadrant pain, nausea/vomiting, diarrhea, anorexia, medical history (of previous non-surgically treated appendicitis, diabetes, hypertension, dyslipidemia, liver cirrhosis, hemodialysis, chronic lung diseases, malignant tumors, immunosuppressant use, and antiplatelet use), vital signs, physical findings, and laboratory data to select the explanatory variates for logistic regression. Based on the univariate comparisons, we performed logistic regression for clinical differentiation between CA and SA using only non-laboratory factors and also including both non-laboratory and laboratory factors.

RESULTS

The 236 eligible patients consisted of 198 patients (83.9%) with SA and 38 patients (16.1%) with CA. The median ages were 34 years old [interquartile ranges (IR), 24-45 years] in the SA group and 49 years old (IR, 35-63 years) in the CA group (P < 0.001). The median onset-to-visit interval was 1 d (IR, 0-1) and 1 d (IR, 1-2) in the SA and CA groups, respectively (P < 0.001). Heart rate, body temperature, and serum CRP level in the CA group were significantly higher than in the SA group; glomerular filtration rate and serum sodium were significantly lower in the CA group. Anorexia was significantly more prevalent in the CA group. The regression model including age, onset-to-visit interval, anorexia, tachycardia, and fever as non-laboratory predictive factors of CA (Model 1) showed that age ≥ 65 years old, longer onset-to-visit interval, and anorexia had significantly high odds ratios. The logistic regression for prediction of CA including age, onset-to-visit interval, anorexia, serum CRP level, hyponatremia (serum sodium < 135 mEq/L), and glomerular filtration rate < 60 mL/min/1.73 m² (Model 2) showed that only elevated CRP levels had significantly high odds ratios. Under the curve values of receiver operating characteristics curves of each regression model were 0.74 for Model 1 and 0.87 for Model 2.

CONCLUSION

Our logistic regression analysis on differentiating factors of CA from SA showed that high CRP level was a strong dose-dependent predictor of CA.

Five Tips for Becoming an Ideal General Hospitalist

Owing to the social structure issues caused by Japan’s super-aged society, health-care roles have become more complex, and the need for general physicians has increased. General hospitalists in Japan perform various roles. Thus, the ideal image of general hospitalists there has been unclear. We summarize the 10 key skills for Japanese hospitalists indicated in the specialty programs of the Japanese Society of Hospital General Medicine. We identified the following five crucial points for ideal general hospitalists: general mindset; leadership and management; community-based comprehensive care and cooperation with various professions; appropriate medical interviewing, physical examination, and diagnostic reasoning; and proactive education and academic activities. This paper presents five tips, which deal with why those items are necessary and how they should be learned.

Characteristics of 22q 11.2 deletion syndrome undiagnosed until adulthood: an example suggesting the importance of psychiatric manifestations

Patients with chromosome 22q11.2 deletion syndrome (22q11.2DS) exhibit various combinations of signs and symptoms including facial dysmorphism, thymus absence, hypoparathyroidism, cellular immunodeficiency and cardiac abnormalities caused by microdeletion of chromosome 22q11.2. Most cases are diagnosed during post-natal cardiac evaluation, though some are diagnosed at later stages. We report the case of a 39-year-old man with 22q11.2DS presenting with seizure due to tardily manifested hypocalcaemia and anxiety disorder. Our experience suggests that 22q11.2DS patients lacking fatal or well-recognised manifestations such as cardiac defects, immunodeficiency and facial dysmorphism tend to survive without medical attention, and are therefore overlooked. Recognition of the age-related variance of the manifestations, and specifically of tardily manifested hypocalcaemia and psychiatric or developmental disorders as manifestations of 22q11.2DS in adulthood, is important for diagnosis and can also help us provide appropriate medical and psychosocial support for newly diagnosed 22q11.2DS patients in adolescence or adulthood and their families.

Antepartum ornithine transcarbamylase deficiency

Ornithine transcarbamylase deficiency (OTCD) is the most common type urea cycle enzyme deficiencies. This syndrome results from a deficiency of the mitochondrial enzyme ornithine transcarbamylase, which catalyzes the conversion of ornithine and carbamoyl phosphate to citrullin. Our case was a 28-year-old female diagnosed with OTCD following neurocognitive deficit during her first pregnancy. Although hyperammonemia was suspected as the cause of the patient's mental changes, there was no evidence of chronic liver disease. Plasma amino acid and urine organic acid analysis revealed OTCD. After combined modality treatment with arginine, sodium benzoate and hemodialysis, the patient's plasma ammonia level stabilized and her mental status returned to normal. At last she recovered without any damage left.

Clinical differentiation of acute appendicitis and right colonic diverticulitis: A case-control study

BACKGROUND

Acute right colonic diverticulitis (ARCD) is an important differential diagnosis of acute appendicitis (AA) in Asian countries because of the unusually high prevalence of right colonic diverticula. Due to qualitative improvement and the high penetration rate of computed tomography (CT) scanning in Japan, differentiation of ARCD and AA mainly depends on this modality. But cost, limited availability, and concern for radiation exposure make CT scanning problematic. Differential findings of ARCD from AA are based on several small studies that used univariate comparisons from Korea and Taiwan. Previous studies on clinical and laboratory differences between AA and ARCD are limited.

AIM

To determine clinical differences between AA and ARCD for differentiation of these two diagnoses by creating a logistic regression model.

METHODS

We performed an exploratory single-center retrospective case-control study evaluating 369 Japanese patients (age ≥ 16 years), 236 (64.0%) with AA and 133 (36.0%) with ARCD, who were hospitalized between 2012 and 2016. Diagnoses were confirmed by CT images. We compared age, sex, onset-to-visit interval, epigastric/periumbilical pain, right lower quadrant (RLQ) pain, nausea/vomiting, diarrhea, anorexia, medical history, body temperature, blood pressure, heart rate, RLQ tenderness, peritoneal signs, leukocyte count, and levels of serum creatinine, serum C-reactive protein (CRP), and serum alanine aminotrans-ferase. We subsequently performed logistic regression analysis for differentiating AA from ARCD based on the results of the univariate analyses.

RESULTS

In the AA and ARCD groups, median ages were 35.5 and 41.0 years, respectively (p=0.011); median onset-to-visit intervals were 1 [interquartile range (IQR): 0-1] and 2 (IQR: 1-3) days, respectively (P < 0.001); median leukocyte counts were 12600 and 11500/mm³, respectively (P = 0.002); and median CRP levels were 1.1 (IQR: 0.2-4.1) and 4.9 (IQR: 2.9-8.5) mg/dL, respectively (P < 0.001). In the logistic regression model, odds ratios (ORs) were significantly high in nausea/vomiting (OR: 3.89, 95%CI: 2.04-7.42) and anorexia (OR: 2.13, 95%CI: 1.06-4.28). ORs were significantly lower with a longer onset-to-visit interval (OR: 0.84, 95%CI: 0.72-0.97), RLQ pain (OR: 0.28, 95%CI: 0.11-0.71), history of diverticulitis (OR: 0.034, 95%CI: 0.005-0.20), and CRP level > 3.0 mg/dL (OR: 0.25, 95%CI: 0.14-0.43). The regression model showed good calibration, discrimination, and optimism.

CONCLUSION

Clinical findings can differentiate AA and ARCD before imaging studies; nausea/vomiting and anorexia suggest AA, and longer onset-to-visit interval, RLQ pain, previous diverticulitis, and CRP level > 3.0 mg/dL suggest ARCD.

Idiopathic mesenteric phlebosclerosis associated with herbal drugs presenting with asymptomatic fecal occult blood

A 77‐year‐old man who had been taking Chinese herbal drugs containing gardenia fruit for a long time visited our hospital following a positive fecal occult blood test. A computed tomography scan showed multiple linear calcifications distributed on the right‐side mesenteric veins, which is a typical finding of idiopathic mesenteric phlebosclerosis (IMP).

A Study of Morphological Changes in Renal Afferent Arterioles Induced by Angiotensin II Type 1 Receptor Blockers in Hypertensive Patients

BACKGROUND

Renin-angiotensin-aldosterone system blockers are known to reduce hypertrophy of vascular smooth muscle cells (SMCs) in hypertensive cases. However, we have reported marked proliferative changes of renal afferent arteriolar SMCs in rats induced by a long-term administration of angiotensin II type 1 receptor blockers (ARBs) and an angiotensin-converting enzyme inhibitor (ACEI). In this study, we examined the morphological changes of afferent arteriolar walls in human kidneys with or without ARBs/ACEIs.

METHODS

Forty-four wedge resections were taken from patients aged 45-74 years from 92 nephrectomized kidneys due to malignancy at Toho University Omori Medical Center between 2013 and 2016. They were divided into the following three groups: 18 hypertensive patients treated with antihypertensive agents including ARBs or ACEIs (the HTARB group), 6 hypertensive patients treated with calcium channel blockers without ARBs/ACEIs (the HTCCB group), and 20 normotensive patients (the normotensive group) as a control. Cases expecting vascular changes such as diabetes were excluded. In each case renal arterioles were measured as the ratio of inner/outer arteriolar diameter, and pathologists estimated morphological abnormal changes, scoring each specimen independently.

RESULTS

The ratio in the HTARB group was 0.39 ± 0.05 (mean ± SD), and was significantly the lowest among the three groups (0.46 ± 0.02 in the HTCCB, 0.53 ± 0.02 in the normotensive group; p = 0.0107 vs. HTCCB, p = 0.00001 vs. normotensive). The ratio in the three groups significantly correlated with the estimated glomerular filtration rate (r = 0.4915, p < 0.0007). The afferent arteriolar SMCs in the HTARB group frequently showed marked proliferative and irregular changes. The score of SMC abnormalities estimated regarding the proliferation, irregularity of the arrangement, and size in hilar afferent arteriolar SMCs was highest in the HTARB group and showed statistical significance (p = 0.0088, p = 0.00001, and p = 0.025 versus other two groups).

CONCLUSIONS

We consider that these morphological changes in arterioles are induced by ARBs/ACEIs. These changes could induce an important suppression of glomerular hyperfiltration and could lead to glomerular ischemia. However, the clinical consequences of these morphological changes in correlation with ARBs/ACEIs were not sufficiently clear and require further analysis. We should consider renal arteriolar morphological changes when using ARBs/ACEIs.

13C-glucose breath tests: a non-invasive method for detecting early clinical manifestations of exogenous glucose metabolism in type 2 diabetic patients

AIMS

¹³C-glucose breath tests are reported as an alternative non-invasive method to evaluate glucose metabolism. However, the metabolic results differ based on the site of the carbon atom in the glucose. The aim of this study was to evaluate changes in the metabolism of carbon atoms contained in glucose in patients with diabetes using [1, 2, 3-¹³C]glucose breath tests.

METHODS

Sixteen healthy participants and 20 diabetic patients were enrolled in the study. Three types of breath tests, [1-¹³C], [2-¹³C], and [3-¹³C]glucose breath tests, were performed after an overnight fast. Breath samples were taken at baseline and at 10-min intervals over 150 min, and ¹³CO₂ excretion curves were expressed using non-dispersive infrared isotope spectrometry.

RESULTS

¹³CO₂ levels increased more rapidly, and the peak value of ¹³CO₂ (C_max) was highest after the administration of [3-¹³C]glucose followed by [2-¹³C] and [1-¹³C]glucose in controls. Delayed ¹³CO₂ excretion and a low area under the curve through 150 min (AUC₁₅₀) were obtained in diabetic patients. The group with severe diabetes had a significantly lower C_max and AUC₁₅₀ in the [1-¹³C]glucose breath test.

CONCLUSIONS

The [1-¹³C]glucose breath test, which has been used to evaluate glucose metabolism, is suitable for patients with late-stage diabetes, whereas the [2-¹³C]glucose breath test is ideal in the early stages. Although the [3-¹³C]glucose breath test is theoretically useful for evaluating the uptake of glucose and the anaerobic glycolysis system, it can be used in practice to distinguish reduced uptake from impaired oxidation of glucose in combination with the other two tests.

Sex difference in clinical presentation of patients with infectious mononucleosis caused by Epstein-Barr virus

INTRODUCTION

There are few studies on sex difference in patients with infectious mononucleosis caused by Epstein-Barr virus (EBV-IM). We performed a retrospective study to evaluate the sex difference in clinical presentation of patients with EBV-IM.

METHODS

We performed a single-center retrospective study evaluating >14-year-old patients with serologically confirmed EBV-IM during 2006-2017. We compared the patients' age, symptoms, physical findings, and laboratory data between male and female patients. To adjust for confounding factors, we performed a logistic regression analysis based on the results of univariate comparisons.

RESULT

Of the 122 eligible patients (56 male and 66 female, ratio: 1:1.2), the median ages were 26 years old (interquartile range [IR], 22-31.5 years old]) and 22 years old (IR, 20-25 years old) for males and females, respectively (p < 0.001). Headache was significantly more prevalent in males (25.0% vs. 10.6%, p = 0.036). Leukocyte count was also significantly higher in males (11,400/mm³ [IR, 7,600-14,100/mm³] vs. 9,400/mm³ [IR, 6,600-11,600/mm³], p = 0.021). The prevalence of periorbital edema (male: 3.6% vs. female: 18.1%, p = 0.012) and severity of transaminase elevation were significantly higher in females. The regression analysis evaluating clinical characteristics of male patients showed that age >30 years old, headache, and leukocyte >11,000/mm³ had high odds ratios.

CONCLUSION

Our single-center retrospective study suggests that older age of onset, headache, and leukocytosis are more likely to be characteristics of male patients with EBV-IM. Our study also underscores the importance of periorbital edema as a clue for early diagnosis of EBV-IM, especially in female patients.

Breath Hydrogen Gas Concentration Linked to Intestinal Gas Distribution and Malabsorption in Patients with Small-bowel Pseudo-obstruction

BACKGROUND

The patient with colonic obstruction may frequently have bacterial overgrowth and increased breath hydrogen (H2) levels because the bacterium can contact with food residues for longer time. We experienced two cases with intestinal obstruction whose breath H2 concentrations were measured continuously. CASE 1: A 70-year-old woman with small bowel obstruction was treated with a gastric tube. When small bowel gas decreased and colonic gas was demonstrated on the plain abdominal radiograph, the breath H2 concentration increased to 6 ppm and reduced again shortly. CASE 2: A 41-year-old man with functional small bowel obstruction after surgical treatment was treated with intravenous administration of erythromycin. Although the plain abdominal radiograph demonstrated a decrease of small-bowel gas, the breath H2 gas kept the low level. After a clear-liquid meal was supplied, fasting breath H2 concentration increased rapidly to 22 ppm and gradually decreased to 9 ppm despite the fact that the intestinal gas was unchanged on X-ray. A rapid increase of breath H2 concentration may reflect the movement of small bowel contents to the colon in patients with small-bowel pseudo-obstruction or malabsorption following diet progression.

CONCLUSIONS

Change in breath H2 concentration had a close association with distribution and movement of intestinal gas.

Anisakiasis: The risks of seafood consumption

Context and Aims

Japanese cuisine is now popular worldwide, and consumption of raw fish has thus increased at sushi bars and Japanese restaurants outside Japan. Anisakiasis, also known as herring-worm disease, is caused by ingesting larval nematodes in raw seafood and is a common illness in Japan. However, due to the rising popularity of Japanese food, gastroenterologists outside Japan need to be familiar with this disease.

Subjects and Methods and Results

We treated 158 patients presenting with acute gastrointestinal manifestations caused by anisakiasis from April 1991 to April 2000. One or more nematodes were removed endoscopically within 48 h of presentation in 44% of these patients, which resulted in prompt resolution of symptoms. Major endoscopic findings were gastric ulcer accompanied by hemorrhage, erosion, redness, and edema of the gastric mucosa in areas penetrated by larvae and other areas.

Conclusions

Endoscopy was valuable for the diagnosis and treatment of anisakiasis. We recommend endoscopy in suspected cases of anisakiasis. Moreover, it is desirable to combine complementary tests such as immunological tests/IgE measurement. As the popularity of Japanese cuisine increases, reports of anisakiasis are likely to be more frequent in countries other than Japan.

Pseudo-thrombotic Microangiopathy Caused by Acquired Cobalamin Deficiency Due to Unintentional Neglect

Acquired vitamin B₁₂ (VB₁₂) deficiency is a rare cause of thrombotic microangiopathy (TMA). We experienced an 86-year-old Japanese woman who presented with coma, renal dysfunction, and microangiopathic hemolytic anemia. Although we initially considered thrombotic thrombocytopenic purpura, we eventually diagnosed her to have VB₁₂ deficiency due to inappropriate dietary care based on her low serum VB₁₂ level, social history, and negative parietal cell finding and the presence of intrinsic factor antibody. Because similar cases are expected to increase in today's aging society, our experience underscores the importance of including acquired VB₁₂ deficiency in the differential diagnosis of TMA, even in elderly patients without a history of gastrectomy.

Chikungunya Virus Infection Presenting with Persistent Arthralgia without Fever

Chikungunya virus infection (CVI) typically manifests via a “two‐phase” presentation: most patients develop acute fever and some patients subsequently develop arthralgia that can persist for years. Many patients visit clinics during the second phase, for relief of the arthralgia, but not during the acute febrile phase. We report a 25‐year‐old Japanese man infected with CVI in Jamaica who presented with chronic disabling peripheral‐dominant symmetric polyarthralgia without fever, which affected the neck, knees, elbows, wrists, and fingers. Given the recent emergence of dengue fever in Japan, clinicians should consider CVI as a differential diagnosis of dengue fever when examining travelers complaining of persistent arthralgia, regardless of their countries of origin.

Renal vein thrombosis associated with oral contraception and smoking: a case report from Japan, with literature review

Renal vein thrombosis, one of the common thrombotic complications of nephrotic syndrome or renal cell carcinoma, is reportedly a rare complication of hormonal contraception. Solitary renal vein thrombosis in the Japanese population is thought to be very rare because the incidence of venous thromboembolism is comparatively very low in Asian populations. We report a 38-year-old Japanese female with left renal vein thrombosis associated with oral contraception and concurrent smoking as the first Japanese case of solitary renal vein thrombosis associated with oral contraceptives, with a review of the literature. Seven cases were previously reported. The results revealed that all patients complained of acute onset of pain around the involved kidney without urinary symptoms or fever, and were effectively treated with anticoagulants. Other remarkable facts include that nausea and vomiting were frequently seen, and that the renal outcome was benign, despite various initial urine abnormalities. This report may alert clinicians to the importance of these risk factors as an etiology of renal vein thrombosis even in Asian populations. Clinicians should regard renal vein thrombosis as one of the differential diagnoses for acute flank pain in patients using oral contraceptives. A detailed history taking that reveals oral contraception, smoking, and other thrombophilic predispositions as well as timely computed tomographic scans would be the keys to diagnosis. Smoking cessation should be strongly recommended to oral contraceptive users, especially women over 35 years of age, regardless of dosage.

Metronidazole-induced encephalopathy associated with treatment for liver abscesses

Metronidazole‐induced encephalopathy (MIE) is a rare condition in Japan. We report the case of a patient with MIE who presented with abducens paralysis and ataxia without underlying risk factors. A history of metronidazole (MNZ) administration and rapid improvement after MNZ discontinuation are important in making this diagnosis, and characteristic findings of magnetic resonance imaging support the diagnosis. MIE is expected to become common in Japan as the use of MNZ increases because of expanded insurance coverage. Therefore, MIE needs to be recognized as a differential diagnosis of the central nervous symptoms in patients taking MNZ.

Giant oesophageal gastrointestinal stromal tumour presenting with dyspnoea and clubbed fingers

Gastrointestinal stromal tumours (GISTs) are mesenchymal neoplasms of the gastrointestinal tract originating from the interstitial cells of Cajal. Giant oesophageal GISTs are rare since the oesophagus is rarely the primary site of GISTs, and they are usually diagnosed early due to complaints such as dysphagia. We present the case of a giant oesophageal GIST presenting with prominent clubbing. The case underlined the diagnostic importance of clubbing and the careful consideration of chemotherapy. Although clubbed fingers associated with GISTs are rare, our experience demonstrates the importance of physicians' recognition of clubbing as a paraneoplastic phenomenon for early diagnosis of malignancies since patients seldom notice their own clubbing by themselves. Chemotherapy using imatinib, an Bcr-Abl kinase inhibitor, is the standard option for unresectable giant GISTs. However, careful consideration must be made of the risk of complications associated with rapid mass reduction due to imatinib such as bleeding, oesophageal perforation and mediastinitis.

Effects of ethanol and sex on propionate metabolism evaluated via a faster 13C-propionate breath test in rats

BACKGROUND

Alcoholism is regarded as a risk factor for vitamin B₁₂ (VB₁₂) deficiency. Because VB₁₂ serves as a coenzyme of methylmalonyl-CoA mutase, a key enzyme in propionate metabolism, the ¹³C-propionate breath test (PBT) has been studied as a non-invasive diagnostic modality for VB₁₂ deficiency. However, the conventional PBT requires 2 h, which is inconvenient in clinical practice. We hypothesized that a faster PBT can be used to evaluate propionate metabolism and is more easily adaptable for clinical practice.

AIM

To evaluate a faster PBT for assessing the effects of long-term ethanol consumption on propionate metabolism in ethanol-fed rats (ERs).

METHODS

ERs were obtained by replacing standard drinking water (for control rats, CRs) with 16% ethanol solution in descendants of F344/DuCrj rats. Faster PBT was performed by administering ¹³C-propionate aqueous solution to male and female ERs and CRs by inserting a metal tubule from the mouth to the stomach; exhaled gas was collected in a bag to measure its ¹³CO₂/¹²CO₂ isotope ratio via infrared isotope spectrometry. Serum VB₁₂ and alanine transaminase (ALT) levels were measured via chemiluminescence immunoassay and the lactate dehydrogenase-ultraviolet method, respectively. We evaluated statistical differences in mean body weight, change in ¹³CO₂ (Δ¹³CO₂‰), peak Δ¹³CO₂‰, and serum VB₁₂ and ALT, between males and females and between ERs and CRs using the t-test and Mann-Whitney U test for normally and non-normally distributed variables, respectively.

RESULTS

Males weighed significantly more than females (P < 0.001); CRs weighed significantly more than ERs (P < 0.008). Δ¹³CO₂ reached a peak (C_max) at 20 min and 30 min in females and males, respectively, decreasing after 20-30 min without rebound in all groups. Males had significantly higher C_max and Δ¹³CO₂ at 15-45 min than females (P < 0.05; for all pairs). Propionate metabolism was enhanced in male ERs relative to male CRs, whereas metabolism did not differ markedly between ERs and CRs for females. Males had higher serum VB₁₂ levels than females, without prominent differences between the ER and CR groups. Male CRs had notably higher ALT levels than male ERs. Thus, chronic ethanol consumption may trigger fatty acid production via intestinal bacteria and changes in gut microbiome composition.

CONCLUSION

Faster PBT shows that 16% ethanol consumption promotes propionate metabolism without inducing liver injury. This PBT may be used clinically to evaluate gut flora status.