Toxicologic Causes of Acute Abdominal Disorders

Effects of acupuncture on gastrointestinal diseases and its underlying mechanism: a literature review of animal studies

Acupuncture is a non-pharmacological traditional Chinese medical technique that has been used for various types of gastrointestinal (GI) diseases in Eastern medicine. However, the specific mechanisms underlying acupuncture treatment in the GI tract have not yet been elucidated. In this study, we searched the electronic databases PUBMED, EMBASE, and MEDLINE and identified 30 eligible studies that were summarized in this review. This review demonstrates that treatments, including both manual and electroacupuncture, have therapeutic mechanisms in diverse GI diseases. The underlying mechanisms are broadly divided into the following: changes in gene expression in the gastric mucosa or nuclei of the solitary tract, metabolic change induction, regulation of anti-inflammatory substances, vagal activity increase, change in functional connectivity between brain regions, and control of the number of neurons related to GI diseases. Although this study is limited in that it does not represent all types of GI diseases with different acupuncture methods, this study identified acupuncture as effective for GI diseases through various biological mechanisms. We hope that our study will reveal various mechanisms of acupuncture in GI diseases and play an important role in the therapy and treatment of GI diseases, thus advancing the field of study.

Exposure to Arsenite in CD-1 Mice during Juvenile and Adult Stages: Effects on Intestinal Microbiota and Gut-Associated Immune Status

Intestinal microbiota composition and gut-associated immune response can contribute to the toxicity of arsenic. We investigated the potential toxicity of short-term arsenic exposure on gut microbiome composition, intestinal immune status, microbial arsenic resistance gene, and arsenic metabolic profiles in adult and developmental stages of CD-1 mice. The potential toxicity of arsenite [As(III)] was determined for two life stages: (i) adult animals at 24 or 48 h after single gavage (0.05 mg/kg body weight [b.w.] [low dose], 0.1 mg/kg b.w. [medium dose], and 0.2 mg/kg b.w. [high dose]) and repeated exposure at 1 mg/liter for 8 days and (ii) postnatal day 10 (PND10) and PND21 after single gavage (0.05 mg/kg b.w.). Dose- and time-dependent responses in bacterial recovery/microbial composition were observed in adults after a single gavage. Repeated exposure caused a transient decrease in the recovery of intestinal bacteria, a shift in the bacterial population with abundance of arsenic resistance genes, and evidence for host metabolism of arsenite into less-reactive trivalent methylated species. Arsenic exposure in adult animals induced high levels of CC chemokines and of proinflammatory and anti-inflammatory cytokine secretion in intestine. Arsenic exposure at PND21 resulted in the development of distinct bacterial populations. Results of this study highlight significant changes in the intestinal microbiome and gut-associated immune status during a single or repeated exposure to arsenic in juvenile and adult animals. The data warrant investigation of the long-term effects of oral arsenic exposure on the microbiome and of immune system development and responses.IMPORTANCE Transformation of organic arsenic to toxic inorganic arsenic (iAs) is likely carried out by intestinal bacteria, and iAs may alter the viability of certain microbial populations. This study addressed the impact of arsenic exposure on intestinal microbiota diversity and host gut-associated immune mediators during early development or adulthood using scenarios of acute or repeated doses. During acute arsenic exposure, animals developed defense functions characterized by higher abundances of bacteria that are involved in arsenic resistance or detoxification mechanisms. Arsenite had a negative effect on the abundance of bacterial species that are involved in the conversion of protein to butyrate, which is an alternative energy source in the intestine. The intestinal mucosal immune cytokine profile reflected a mechanism of protection from arsenic toxicity.

Therapeutic interventions using a combination of Telmisartan and omega 3-fatty acids in sodium arsenite-induced vascular endothelial dysfunction in rats: modulation through ATP-sensitive K+ channels and eNOS

BACKGROUND

Effective diet/drug combinations may show additive or synergistic effects in reducing endothelial risk factors vis-à-vis monotherapies. The study evaluated the effect of combined therapy of Telmisartan and omega 3-fatty acids in sodium arsenite-induced vascular endothelial dysfunction (VED) in rats.

METHODS

Forty-eight male Wistar rats (180-220 g) were randomized into eight groups; control, sodium arsenite (1.5 mg/kg/day) exposed, sodium arsenite exposure followed by treatment with Telmisartan, omega 3-fatty acids, the combination and/or endothelial modulators for 2 weeks depending on the allocated group. VED was assessed by estimating vascular reactivity. Serum thiobarbituric acid-reactive substances (TBARS), nitrite/nitrate levels, reduced glutathione (GSH) levels, superoxide dismutase (SOD) activity, serum cholesterol and triglyceride levels were also determined.

RESULTS

Sodium arsenite produced VED by attenuating acetylcholine-induced endothelial relaxation (% Rmax= 45.36), decreasing levels of serum nitrite/nitrate (9.28 μM/mg protein), GSH (16.06 μg/mg of protein), SOD activity (30.69 units/mg protein) and increasing TBARS (0.19 µM/mg protein) compared with control group. The combined therapy with Telmisartan (10 mg/kg/day) and omega 3-fatty acids (180 mg/kg/day) (% Rmax = 80.93, 13.09 µM/mg protein, 25.93 μg/mg of protein, 57.84 units/mg protein and 0.08 µM/mg protein, respectively) significantly abolished the respective derangements induced by sodium arsenite. Further, this combination significantly prevented rise in serum cholesterol and triglyceride levels that was induced by sodium arsenite. However, the ameliorative effects of this combination were abated by N-omega-nitro-L-arginine methyl ester (L-NAME) and glibenclamide.

CONCLUSIONS

Combined therapy of Telmisartan and omega 3-fatty acids attenuated VED, by activating enzyme nitric oxide synthase (eNOS) through opening of ATP-sensitive K(+) channels.

Acute intestinal pseudo-obstruction after induction treatment of relapsed acute promyelocytic leukemia with arsenic trioxide

Arsenic trioxide (As(2)O(3)) is an effective agent for the treatment of relapsed acute promyelocytic leukemia (APL). We report a patient with intestinal pseudo-obstruction, which occurred while treating relapsed APL with As(2)O(3). A 6-year-old female with relapsed APL developed paralytic ileus, hyperleukocytosis, and a high fever while being treated with As(2)O(3). Although As(2)O(3) was discontinued and dexamethasone was administered, vomiting and abdominal distension worsened. An ileostomy was performed and diffuse patch-like infiltrations on the bowel surface were noted. Pathologic findings revealed APL cells involving the entire intestinal layers. This case history suggests that As(2)O(3) when used for reinduction therapy for APL may adversely affect the intestine and cause acute intestinal pseudo-obstruction.

Unusual causes of abdominal pain

Common and uncommon GI and other intraperitoneal illnesses may present in unusual ways. In addition, many systemic or extraperitoneal disease processes frequently include abdominal pain as a clinical manifestation. The clinician should suspect an unusual cause of abdominal symptoms in patients with repeated visits to the ED without a diagnosis, those who appear ill or complain of severe abdominal pain with disproportionately negative abdominal physical examination findings, those with constitutional or extraperitoneal symptoms or signs, and the elderly or immunocompromised. After initial resuscitation and stabilization have taken place, early evaluation of the need for urgent surgical evaluation and operative management is crucial in the patient with abdominal pain, even when the cause of the symptoms is unclear. A thorough history and careful and complete abdominal and nonabdominal physical examination, paired with appropriate but judicious diagnostic testing, are essential to detecting these unusual causes of abdominal pain and to preventing needless morbidity and mortality.

Intestinal infarction due to nifedipine overdose

The first case of intestinal infarction associated with nifedipine overdose is presented. This is also the first reported case of an overdose with an extended release nifedipine preparation. The formation of a large gastric concretion of nifedipine tablets may have enhanced its local vasodilatory effects thereby producing mesenteric hypoperfusion, ischemia, and infarction.

Charcoal stercolith with intestinal perforation in a patient treated for amitriptyline ingestion

A case of a patient who developed an intestinal perforation secondary to a charcoal stercolith is reviewed. The case involves a young female on methadone maintenance who received multiple-dose charcoal therapy for an amitriptyline ingestion. Peritoneal signs developed several days after admission, and an exploratory laparotomy was done. A perforation measuring 4 cm in diameter was found in the posterior wall of the sigmoid colon. A 120-gm obstructing charcoal mass was found at the site of the perforation. Previous reports of intestinal obstruction secondary to charcoal inspissation are noted, and case similarities are discussed. All reported cases of charcoal obstruction involve the administration of multiple-dose-activated charcoal in the treatment of ingestions of medications known to have antiperistaltic activity. With a rare potential of mechanical obstruction, the decision to use repetitive-dose charcoal therapy should be made judiciously when the ingested toxin or coincident therapeutic medications have antiperistaltic activity.

Massive ingestion of sustained-release verapamil with a concretion and bowel infarction

Gastric concretions secondary to a drug overdose are uncommon but potentially fatal if not recognized and treated. They may continue to release drug into the stomach for hours or days after the ingestion, complicating diagnosis and treatment. We describe the case of a man with the previously unreported association of bowel infarction with a verapamil ingestion and concretion. This case illustrates the need for a heightened awareness of this potential complication.