A novel adolescent chronic social defeat model: reverse-Resident-Intruder Paradigm (rRIP) in male rats.

Psychosocial stress is linked to the etiology of several neuropsychiatric disorders, including Major Depressive Disorder and Post-Traumatic-Stress-Disorder. Adolescence is a critical neurobehavioral developmental period wherein the maturing nervous system is sensitive to stress-related psychosocial events. The effects of social defeat stress, an animal model of psychosocial stress, on adolescent neurobehavioral phenomena are not well explored. Using the standard Resident-Intruder-Paradigm (RIP), adolescent Long-Evans (LE, residents, n = 100) and Sprague-Dawley (SD, intruders, n = 100) rats interacted for five days to invoke chronic social stress. Tests of depressive behavior (forced-swim-test (FST)), fear conditioning, and long-term synaptic plasticity are affected in various adult rodent chronic stress models, thus we hypothesized that these phenomena would be similarly affected in adolescent rats. Serendipitously, we observed the Intruders became the dominant rats and the Residents were the defeated/submissive rats. This robust and reliable role-reversal resulted in defeated LE-Residents showing a depressive-like state (increased time spent immobile in the FST), enhanced fear conditioning in both hippocampal-dependent and hippocampal-independent fear paradigms and altered hippocampal long-term synaptic plasticity, measured electrophysiologically in vitro in hippocampal slices. Importantly, SD-Intruders, SD and LE controls did not significantly differ from each other in any of these assessments. This reverse-Resident-Intruder-Paradigm (rRIP) represents a novel animal model to study the effects of stress on adolescent neurobehavioral phenomenon.

Malicious Mushrooms.

Accidental ingestion of the toxic Death Cap mushroom, and others of the Amantina species, can occur due to their physical similarities with commonly edible fungi. Production of certain toxins which prevent protein synthesis can lead to fulminant organ failure and death. Although treatment is mostly supportive due to a lack of specific antidote, early recognition can aid in meaningful recovery. Nonspecific symptoms are generally present early in the course and, therefore, high index of suspicion is required. We present 2 cases of suspected Amanita phalloides poisoning leading to acute liver injury; one leading to resolvement of symptoms and the other being fatal.

Sarcoid Here, Sarcoid There, Sarcoid Everywhere.

Although usually more associated with the lungs, sarcoidosis can have multiple extrapulmonary manifestations. We present a case of a patient with previous biopsy-proven sarcoidosis who was admitted to the hospital secondary to worsening shortness of breath. The patient was found to be positive for Respiratory Syncytial Virus (RSV) which was believed to have exacerbated his pulmonary symptoms. He was treated with IV steroids, nebulizers, and antibiotics which ultimately helped relieve his symptoms. In terms of his sarcoidosis, he was previously treated in the past with steroids in regards to this pathology (which is the mainstay of treatment); while on the regimen, the patient noted his breathing was improved. Of note, he did also have a history of renal cell carcinoma (RCC) status post nephrectomy which was initially evaluated for possible sarcoidosis involvement. This medical therapy could also have been the reason his sarcoidosis did not progress to involve other organs.

A Case Report of Brucellosis-Associated Infective Endocarditis.

Brucellosis is a prevalent zoonotic infection that can be relatively well managed and tolerated if appropriate treatment is initiated. Unfortunately, likely secondary to decreased awareness and vague symptoms, the diagnosis can be easily missed leading to worsening complications that severely increase the mortality rate. We present a case of a 25-year-old female who presented from a rural setting with a diagnosis of brucellosis, which was delayed. She ultimately developed infective endocarditis with cardiac vegetations on imaging. Despite improvement on antibiotics and reduction in size of cardiac vegetation, she suffered a fatal cardiac arrest before undergoing surgical intervention. Better awareness regarding hygiene and sanitary food handling should be encouraged, especially in underdeveloped rural areas, to help prevent infection. More studies need to be performed to help better identify symptoms coupled with maintaining a high index of suspicion so as to expedite diagnosis, treatment, management and hopefully prevent the progression of disease and worsening complications.

To Bleed or Not to Bleed.

The location of gastrointestinal (GI) bleeding can be characterized based on the characteristics of the bowel movements these patients present with. Bright red blood per rectum is usually associated with a lower bleed; if brisk and significant enough, however, upper bleeds can present similarly. Melenic or "tar-colored" bowel movements are more likely to occur from upper bleeds as the color is secondary to digestion of hemoglobin as it passes through the GI tract. At times, there can be a mix of the two which can make a clinical decision for intervention less obvious. To make matters more difficult, some of these patients can be on anticoagulation therapy for a myriad of reasons. Risks versus benefits at these times need to be weighed as holding this therapy may make the patients more prone to clotting while continuation would increase likelihood of bleeding. We present a case of a hypercoagulable patient who was started on rivaroxaban for history of pulmonary embolism; this led to the onset of an acute GI bleed from a duodenal diverticulum requiring endoscopic intervention. Although this can be a known effect of the therapy, the severity of bleed and changes in hemodynamics can warrant very different management strategies.

A Rare Manifestation of Hepatitis A Associated Cryoglobulinemia.

Cryoglobulins can precipitate in the blood when exposed to lower temperatures. These abnormal immunoglobulins are more commonly affiliated with Hepatitis C infection but there have been cases reported with Hepatitis A association for which we present this case. The patient was treated with steroids which did show gradual improvement of symptoms but, ultimately, the patient developed renal failure and required temporary hemodialysis. Care should be taken to assess patients with cryoglobulins for other viral serologies besides Hepatitis C.

Fibrolamellar hepatocellular carcinoma: An epidemiologic and 5-year cancer survival assessment based off SEER data.

The fibrolamellar variant of hepatocellular carcinoma makes up a small percentage of liver tumors. Despite being a subset, it has been noted in the literature to have variations in terms of its epidemiology and intervention recommendations. Using the Surveillance, Epidemiology, and End Results database, 339 cases from 1988 to 2016 were studied. Favorable prognostic epidemiological factors included male sex, younger ages, and white race. Those who underwent any lymph node resection (combined with liver resection) did better than those without lymph node resection; chemotherapy proved beneficial for those where surgery was contraindicated. To our knowledge, this report is the largest conglomerate dataset analyzing prognostic profiles and treatment strategies for fibrolamellar hepatocellular carcinoma.

Cannabinoid modulation of chronic mild stress-induced selective enhancement of trace fear conditioning in adolescent rats.

History of stress is considered a major risk factor for the development of major depression and posttraumatic stress disorder (PTSD). Elucidating the neurobiological mechanisms of Pavlovian fear conditioning may provide insight into the etiology of PTSD. In the current study, adolescent male Sprague-Dawley rats were exposed to 3 weeks of a chronic-mild-unpredictable stress (CMS) protocol. Immediately following the CMS, the animals were subjected to hippocampal-dependent (trace and contextual) and hippocampal-independent (delay) fear conditioning. CMS exposure enhanced trace freezing behavior compared to non-stress controls. This effect was not observed in contextual or delay conditioned animals. Given that the endocannabinoid system is negatively affected by CMS procedures, separate groups of stressed rats were administered the CB1 receptor agonist, ACEA (0.1 mg/kg), prior to trace fear conditioning or a memory-recall test. Regardless of administration time, ACEA significantly reduced freezing behavior in stressed animals. Furthermore, when administered during the first memory recall test, ACEA enhanced long-term extinction in both stress and non-stress groups. The results demonstrate that chronic unpredictable stress selectively enhances hippocampal-dependent episodic fear memories. Pathologies of the episodic memory and fear response may increase the susceptibility of developing PTSD. Reduction in fear responses via exogenous activation of the CB1 receptor suggests that a deficiency in the endocannabinoid system contributes to this pathology.