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Background: Meckel’s diverticulum on the mesenteric side has been reported only as case reports in the literature and presents a diagnostic challenge, with ultimate recognition often taking place intraoperatively. We describe a case series of children with mesenteric Meckel’s diverticulum (MMD) treated at our institution, along with the results of a systematic review of the literature. Methods: Our experience on MMD was analyzed along with a systematic literature review performed according to PRISMA criteria. We identified studies published from 1941 to 2023 from PubMed, EMBASE, SCOPUS, and WOS. Search terms were variations of “Meckel”, “diverticulum”, and “mesenteric”. Inclusion criteria were patients < 18 years of age and articles written in English. Results: A total of three cases of MMD were observed and treated in our hospital. The mean age was 7.6 years. The most common symptoms were rectal bleeding and abdominal pain. Diagnostic workup included ultrasound and both upper and lower endoscopy. Surgery was performed by the laparoscopy-assisted technique. One case had to be reoperated due to postoperative intestinal occlusion. The mean length of hospital stay was 9.3 days. The literature search yielded 795 citations; out of the 590 papers remaining after the exclusion of 205 duplications, only 15 papers matched the inclusion criteria and were included and analyzed. Conclusions: MMD remains a rare and elusive pathology, sharing with its normal counterpart symptoms and signs. In our experience, and in the more recent literature, laparoscopy-assisted surgery appears safe and effective both for final diagnosis and definitive treatment.

PurposeEosinophilic gastrointestinal disorders are rare in children and present with a broad spectrum of non-specific symptoms. To date, no guidelines for diagnosis, therapy and follow-up are validated. Aim of our study is to focus on eosinophilic colitis (EC), to determine a possible correlation between associated disorders, macroscopic findings and treatment/follow up.MethodsRetrospective study from 2015 to 2019 including all colonoscopies performed at our Institution. Eosinophilic colitis was defined according to the threshold identified by Collins: > 100 Eo/Hpf: right colon, > 84 Eo/Hpf transverse and left colon, > 64 Eo/Hpf sigma and rectum. We excluded colonoscopy in patients with IBD or other diseases causing hypereosinophilia (i.e., parasite infection, GVHD).ResultsAmong 399 colonoscopies performed in 355 patients, we made 50 diagnosis of EC, 36 males, 14 females, median age 8.5 (3–17). Symptoms leading to endoscopy were recurrent abdominal pain (66%), chronic diarrhea (64%), and chronic constipation (8%). Two patients presented with GI bleeding and one with weight loss. Macroscopic findings were mostly normal or lymphoid nodular hypertrophy presenting different endoscopic features. In seven children (14%) we found history of allergy and atopy. 22 children present a diagnosis of autistic spectrum disorder (ASD) with a prevalence higher than in the overall population (44% vs 28.5%, p = 0.03). According to symptoms, treatment consist variably of steroids, six food elimination diet, mesalamine. For patients with available follow-up, we found histological persistence of Eosinophils in 75%, even in patients with symptoms relief.ConclusionThis study focus attention on EC as a new challenging pathology. Multicentric randomized clinical trials are needed to understand physiopathological mechanisms to validate a possible endoscopic score and related histological threshold, and to standardize therapy according to clinical features and instrumental findings. The high prevalence of EC in ASD need further specific research.

Recently, it has been shown that nitric oxide may inhibit the Leydig cell steroidogenesis. The present paper describes, by means of NADPH-diaphorase histochemistry, the ultrastructural localization of the enzyme nitric oxide synthase in the Leydig cells of young adult and aging mice. In the young adult mice, the enzymatic reaction was mainly located in the mitochondria and in some clustered cisternae of the smooth endoplasmic reticulum. The nuclear envelope was faintly labeled. In the aging mice, most Leydig cells showed an enhanced enzymatic reaction. Labeled mitochondria were increased in number, and labeled areas of the smooth endoplasmic reticulum were more numerous and extended. In addition, a strong enzymatic reaction was recognized in the nuclear envelope. We conjecture that the impaired steroidogenesis observed in the testis of aging mammals might, at least in part, depend on the increased nitric oxide production in the Leydig cells.

The cavernous sinuses are the most peculiar feature of the nasal angioarchitecture, due to their ability to retain a large quantity of blood in reply to a variety of topical and systemic stimuli. Recently, nitric oxide (NO) has seemed to be crucially involved in the nasal vascular regulation. The distribution of NO-synthase (NOS), the enzyme that catalyzes the formation of NO, was studied in the endothelium of nasal blood vessels by the ultracytochemical detection of reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) enzymic activity. The endothelium of the cavernous sinuses appeared strongly positive, whereas the endothelium of arterioles was occasionally labeled. The endothelial cells of capillaries and venules were found to be NADPH-d negative. The strong enzymic activity observed in the cavernous sinuses suggests a major role of NO in the capacitance vessels compared to the resistance vessels. The hypothesis of a reciprocal inhibition between the NOS enzymic pathways present in the respiratory epithelium and in the endothelium of cavernous sinuses is put forward. The nasal disorders characterized by anomalous vasomotility and vascular permeability could be caused in part by the irregular control of these complex interactions.