Modeling user concerns in Sharing Economy: the case of food delivery apps.

Sharing Economy apps, such as Uber, Airbnb, and TaskRabbit, have generated a substantial consumer interest over the past decade. The unique form of peer-to-peer business exchange these apps have enabled has been linked to significant levels of economic growth, helping people in resource-constrained communities to build social capital and move up the economic ladder. However, due to the multidimensional nature of their operational environments, and the lack of effective methods for capturing and describing their end-users' concerns, Sharing Economy apps often struggle to survive. To address these challenges, in this paper, we examine crowd feedback in ecosystems of Sharing Economy apps. Specifically, we present a case study targeting the ecosystem of food delivery apps. Using qualitative analysis methods, we synthesize important user concerns present in the Twitter feeds and app store reviews of these apps. We further propose and intrinsically evaluate an automated procedure for generating a succinct model of these concerns. Our work provides a first step toward building a full understanding of user needs in ecosystems of Sharing Economy apps. Our objective is to provide Sharing Economy app developers with systematic guidelines to help them maximize their market fitness and mitigate their end-users' concerns and optimize their experience.

Pulsed dye laser versus Nd:YAG laser in the treatment of plantar warts: a comparative study.

Plantar warts are common viral infection that are usually challenging in treatment. Conventional treatment methods are usually invasive, have low efficacy, and need long recovery periods. In this study, we compared pulsed dye laser (PDL) and neodymium yttrium aluminum garnet (Nd:YAG) lasers in the treatment of recalcitrant plantar warts. The study included 46 patients with multiple plantar warts. In each patient, lesions were divided into two groups: one treated with Nd:YAG (spot size, 7 mm; energy, 100 J/cm(2); and pulse duration, 20 ms) and the other with PDL (spot size, 7 mm; energy, 8 J/cm(2); and pulse duration, 0.5 ms). Laser sessions were applied every 2 weeks with maximum of six sessions. The study included 63% males and 37% females with a mean age of 29.6 ± 7.34 years. The cure rate was 73.9% with PDL with no significant difference (p = 0.87) from Nd:YAG (78.3%). The number of sessions required was more in PDL (mean, 5.05 ± 0.2) compared with Nd:YAG (mean, 4.65 ± 0.5) but without significant difference. Complications were significantly higher with Nd:YAG (43.5%) compared with PDL (8.7%). Hematoma was the most common complication recorded by Nd:YAG (28.3 %), and it was significantly higher (p = 0.002) than PDL (2.2%). Relapse was recorded in 8.7% with Nd:YAG compared with 13% in PDL with no significant difference (p = 0.74). Our results suggested that PDL and Nd:YAG lasers are effective in the treatment of resistant plantar warts. PDL is safer and less painful but needs more sessions, while Nd:YAG is more painful and shows more complications.

Rhabdomyosarcoma in Adults: De Novo or Conversion From Non-seminomas?

Rhabdomyosarcoma (RMS) is a highly sporadic, very aggressive, and fatal soft tissue tumor in adults. Although more common and treatable in the pediatric population, the occurrence of pleomorphic RMS in adults has a low incidence. Hence, it is not easy to treat. Surgery is the primary definitive treatment, along with radiation therapy, while adjuvant chemotherapy has recently gained popularity. We present an infrequent case of RMS in a patient with a recent history of mixed non-seminomatous germ-cell tumor testicular cancer. Therefore, it was challenging to treat the RMS as a new malignancy or as a recurrence of non-seminomatous testicular cancer. Our patient passed away, unfortunately, but we hope this case can help the minimal data in this regard in order to save more lives in the future.

From Unassuming to Unbelievable: A Case Report of Pyoderma Gangrenosum.

Pyoderma gangrenosum (PG) is an autoinflammatory skin disease, and there is no definitive test or established criterion for its diagnosis yet. This report discusses a case of a 34-year-old male patient who presented with an unassuming lesion that quickly worsened with physical manipulation. He was eventually diagnosed with PG. This report highlights the importance of a quick and accurate diagnosis of PG to prevent the worsening of a PG wound and its associated morbidity. It provides a detailed description of the condition accompanied by images to further spread awareness of this rare diagnosis.

Atrial Myxoma in a Patient With Chronic Obstructive Pulmonary Disease (COPD): Unmasking Overlapping Symptomatology.

Atrial myxoma, though the most common primary cardiac tumor, often presents with nonspecific symptoms that can obscure its diagnosis. This case report details an unusual presentation of dyspnea on exertion (DOE) in a patient initially considered to have chronic obstructive pulmonary disease (COPD), a common pulmonary etiology of DOE. The diagnostic journey underscores the critical importance of considering atrial myxoma in patients with DOE, especially when symptoms are not fully explained by apparent pulmonary conditions. Our findings highlight the necessity of a comprehensive diagnostic approach, including the early use of resting transthoracic echocardiogram, to unveil less common causes like atrial myxoma. This case reinforces the pivotal role of considering alternative diagnoses in complex presentations of DOE, thereby guiding more accurate and tailored patient management.

Tumor Thrombus of Hepatocellular Carcinoma: A Direct Extension From the Liver to the Right Atrium.

Hepatocellular carcinoma (HCC) is a very aggressive type of cancer and can either invade or spread distantly through the portal vein to the inferior vena cava (IVC) and the right atrium (RA). The presentation varies based on the stage of the cancer at the time of diagnosis. Liver transplantation or surgical resection is the ideal management of small lesions without metastases, while systemic therapy can help in extensive cases to decrease the tumor burden to allow surgical resection of the tumor. We present a rare case of HCC with a tumor thrombus (TT) extending to the RA. Unfortunately, the patient did not survive the cancer. We hope that this case report can contribute to saving the lives of future patients with HCC.

Spindle Cell Carcinoma Presenting as a Massive Pleural Effusion.

The lung's sarcomatoid carcinomas (SC) are a heterogeneous sporadic group of non-small cell lung carcinomas (NSCLCs) and are very challenging to diagnose and treat. Spindle cell carcinoma (SpCC) is a very rare subset of this group. Hence, the prognosis and treatments are unclear due to the limited literature available. The presentation of this cancer varies based on the site of the neoplasm and the complications and metastases observed at the time of diagnosis. Here, we report a 73-year-old man who presented to the emergency room after two months of worsening dyspnea and fatigue. Chest X-ray showed an extensive left-sided pleural effusion. A computed tomography (CT) scan of the chest showed a pleural-based mass that came back as SpCC, for which he was referred to a university hospital.

Sinistral Portal Hypertension Due to a Pancreatic Pseudocyst: A Rare Cause of Upper Gastrointestinal Bleeding.

Sinistral portal hypertension (SPH), also known as segmental portal hypertension, is a complication of pancreatic disorders and an extremely rare cause of upper gastrointestinal (GI) bleeding. SPH is observed in patients without cirrhosis and arises from splenic vein thrombosis. Unmitigated backflow of blood may cause gastric venous congestion and ultimately GI hemorrhage. Herein, we report a rare case of massive hematemesis due to SPH in a male patient with a history of chronic pancreatitis and pancreatic pseudocyst. Our patient was successfully treated with endoscopic necrosectomy followed by open splenectomy, distal pancreatectomy, and partial gastric resection.

Gastric, Colonic, and Rectal Amyloidosis in the Setting of Familial Mediterranean Fever: A Unique Cause of Intractable Diarrhea.

Familial Mediterranean fever (FMF) is a hereditary disorder characterized by episodes of fever, polyserositis, or cutaneous inflammation. The FMF attacks last 1-3 days and have no apparent triggers. Recurrent deposition of the serum amyloid A (SAA) protein in the gut can cause intractable diarrhea, dysmotility, and recurrent abdominal pain. Gastrointestinal amyloidosis is a rare, but serious, complication of FMF. In this case report, we describe a rare case of chronic diarrhea and recurrent abdominal pain due to FMF-induced gastrointestinal amyloidosis.

Rare Direct Locoregional Brain Metastasis and Recurrence in Laryngeal Squamous Cell Carcinoma.

Laryngeal cancer is predominantly a squamous cell in origin that can present with voice changes and difficulty or pain with swallowing. It is more likely to cause local spread than distant ones. The prognosis depends on multiple factors, including the stage, tumor differentiation, extranodal extension, and adjuvant therapy. Head and neck cancers have a higher tendency for perineural invasion and spread, one of the most vital factors correlating with poor outcomes and recurrence rates. We present a rare case of a 52-year-old male with an extensive history of tobacco use (five packs per day over 30 years) who developed laryngeal squamous cell carcinoma that spread to the brain despite total laryngectomy and adjuvant radiation therapy. Despite resection of the brain metastasis, the tumor metastasized again in the brain through perineural spread. Due to the side effects of repeated radiotherapy and starting chemotherapy, the patient opted for comfort care and refused further treatment. The perineural spread of head and neck cancers is not abundant in the literature, and we believe our case will add to the future treatment of head and neck cancers with perineural invasion.

Panniculitis and pancreatitis: Inflammation and necrotic mechanisms in a patient with alcohol use disorder and alarming suspicion for malignant process.

Panniculitis is an inflammatory process localized to subcutaneous tissue, with etiologies including infection, malignancy, external insults, enzymatic destructive processes, and inflammatory disorders. The incidence of panniculitis manifesting as necrosis of subcutaneous fat tissue associated with pancreatic diseases is low, which may encompass associated periarthritis with bone necrosis and panniculitis (Pancreatitis, panniculitis and polyarthritis syndrome). Pancreatitis, panniculitis and polyarthritis syndrome is considered to derive from the systemic activity of enzymes within the pancreas, which leads to disturbances within the microcirculatory system, and fat necrosis of medullary bone marrow; however, the exact pathophysiology remains unknown. Here, we present a case of a 53-year-old male with a history of chronic pancreatitis who presented with lower abdominal pain found to have osteolytic pelvic lesions considered to be panniculitis secondary to pancreatitis. Our patient provided an interesting clinical picture given his alcohol use disorder, and lytic lesions which lead the team initially towards a malignant etiology of panniculitis such as myeloma; however, given his negative studies, it was presumed his panniculitis was derived from his chronic pancreatitis. Overall, additional literature is warranted regarding the extensive workup of lytic bone lesions that present in patients who have acute vs chronic pancreatitis.

Rare Isolated Duodenal Hamartomatous Polyp in an Elderly Patient.

BACKGROUND Hamartomatous polyps represent rare sporadic lesions, characterized by fibrous stroma, vascular infiltration, and dilation of mucous glands. The lesions present in a bimodal fashion in adults as well as children from 1 to 7 years old, and are often diagnosed during endoscopic procedures. Specifically, solitary Peutz-Jeghers represents a type of hamartoma that has similar histologic features to typical Peutz-Jeghers syndrome. Hamartomatous polyps represent disorganized tissue growth and can bear relationships with genetic syndromes classified as hamartomatous polyposis syndromes. A number of these syndromes, such as Peutz-Jeghers and Cowden syndrome, can demonstrate an increased risk of malignancy. A variety of symptoms, or no symptoms at all, can accompany these polyps, such as abdominal discomfort, bowel obstruction, gastrointestinal bleeding, or intussusception in severe cases. Histologically, these polyps appear similar to Peutz-Jeghers syndrome growths; however, they lack extraintestinal manifestations. Given fairly low risk of development into malignancy, patients have a good prognosis if presenting with a solitary hamartomatous polyp. There is limited data regarding screening guidelines for this patient population. CASE REPORT Here, we present a rare case of a 73-year-old woman who had a history of anemia and status post endoscopic evaluation and was diagnosed with a benign hamartomatous polyp (juvenile-like), histologically consistent with tubulovillous adenoma. CONCLUSIONS Differentiating sporadic polyps from syndromic polyps is important, as sporadic polyps have a benign course, while those associated with a syndrome have an increased lifetime malignancy risk.

Aleukemic Acute Promyelocytic Leukemia: How Concomitant HIV, Hepatitis C, and Chronic Alcohol Use Disorder May Have Hidden an Underlying Malignancy.

BACKGROUND Acute promyelocytic leukemia (APL) is a rare subtype of acute myeloid leukemia (AML) and is characterized by a genetic translocation affecting the retinoic acid receptor-alpha gene, leading to blockage in the differentiation of granulocytic cells. The accumulation of promyelocytes in bone marrow leads to cytopenias and life-threatening coagulopathies. Definitive diagnosis is made with bone marrow biopsy. Differentiation of APL from other leukemias is important to appropriately treat with all-trans retinoic acid (ATRA) and arsenic trioxide. Patients with HIV are at a higher risk to develop AML. This article identifies how multiple comorbidities and social factors can contribute to difficulties in diagnosing AML. CASE REPORT We present a 67-year-old man with a past medical history of hypertension and substance use disorder who presented with progressive exertional dyspnea and was found to have HIV, chronic hepatitis C, and APL with pancytopenia. His bone marrow biopsy confirmed AML. This was a case of co-existing HIV and aleukemic leukemia. CONCLUSIONS APL can present with pancytopenia, weakness, failure to thrive, or bleeding complications, which can be similar to presentations of those diagnosed with HIV. Diagnosis of APL can be differentiated between hypergranular and hypogranular; our patient demonstrated APL with only 52% blasts, which can make for a challenging diagnosis. Given increased mortality of APL, immediate ATRA therapy is warranted. Aleukemic leukemia is a rare presentation typically accompanied by skin manifestations. Our case highlights the importance of having high clinical suspicion for malignancy in patients with comorbidities that can interfere with the classic presentation of leukemia.

Rare Case of Refractory Hypokalemia in a Patient with Acute Monocytic Leukemia.

BACKGROUND Refractory hypokalemia has been rarely demonstrated in patients with acute monocytic leukemia (AMoL). Hypokalemia develops in these patients owing to renal tubular dysfunction, secondary to lysozyme enzymes that are released by monocytes in AMoL. Additionally, renin-like substances are produced from monocytes and can lead to hypokalemia and metabolic alkalosis. There is also an entity called spurious hypokalemia, in which high numbers of metabolically active cells in blood samples increase sodium-potassium ATPase activity, resulting in influx of potassium. Additional research is warranted regarding this specific demographic to create standardized treatment approaches to electrolyte repletion. CASE REPORT In this case report, we demonstrate a rare case of an 82-year-old woman with AMoL, complicated by refractory hypokalemia, who presented with concerns of fatigue. The patient's initial laboratory results were significant for leukocytosis with monocytosis and severe hypokalemia. Refractory hypokalemia was noted, despite administration of aggressive repletions. During her hospitalization, AMoL was diagnosed and an extensive workup was performed to evaluate the underlying cause of hypokalemia. Ultimately, the patient died on day 4 of hospitalization. We describe the correlation between severe refractory hypokalemia and leukocytosis and provide a literature review of multiple etiologies of refractory hypokalemia in patients with AMoL. CONCLUSIONS We evaluated the numerous pathophysiologic mechanisms responsible for refractory hypokalemia in patients with AMoL. Our therapeutic outcomes were limited owing to the patient's early death. It is of high importance to evaluate the underlying cause of hypokalemia in these patients and to treat accordingly with caution.

Pain in the Gut: An Intriguing Case of Toothpick Ingestion Causing Gastric Perforation.

Toothpick ingestion is a medical emergency requiring urgent intervention. Swallowed toothpicks can cause intestinal perforation, bleeding, or damage to the surrounding organs. Herein, we describe a unique case of a geriatric patient with a history of peptic ulcer disease who presented to the emergency department for the evaluation of abdominal pain and nausea. Gastric wall thickening concerning for a gastric neoplasm was observed on a computed tomography (CT) scan of the abdomen and pelvis. An esophagogastroduodenoscopy (EGD) revealed an embedded toothpick with a contained gastric perforation, and the foreign body was retrieved with a grasper device. Given the rare presentation, nonspecific symptoms, inability to recall, and often inconclusive imaging, a high index of suspicion is needed for early diagnosis and treatment of toothpick ingestion.

Autoimmune hepatitis presenting with concomitant chronic pancreatitis.

Autoimmune Hepatitis (AIH) is a progressive form of chronic hepatitis, with periods of remissions and exacerbations. Diagnosis includes abnormally high levels of immunoglobulins and multiple autoantibodies. Clinical presentation is variable, with a spectrum extending from asymptomatic cases to fulminant liver failure. Symptoms include abdominal pain, malaise, fatigue, and small joint arthralgia. We present a case of a 36-year-old male with a past medical history of alcohol dependence and acute pancreatitis who was diagnosed with AIH. There is limited data regarding patients with concomitant AIH and pancreatitis. Our patient presented with AIH with secondary acute on chronic pancreatitis, in the absence of additional autoimmune manifestations. The mechanism of AIH remains poorly understood; however, there is an association between the HLA gene and AIH. Genetic studies have shown HLA-DRB1*0301 and HLA-DRB1*0401 as primary and secondary genotypes susceptible to AIH, as well as genetic variants with CARD10 and SH2B3. Products secondary to metabolism of ETOH such as alcohol dehydrogenase, malondialdehyde, and acetaldehyde, can lead to development of autoantibodies. Additional research is indicated to evaluate the relationship between AIH and acute pancreatitis.

Acute Lower Lip Swelling: A Mere Anaphylactic Reaction or a Rare Abscess Location?

An abscess is a collection of pus secondary to an immune response to a pathogen. It can occur anywhere in the body, with the skin as the most common organ involved. A lip abscess is a rare condition. Generally, it may be due to an infective agent such as a virus or bacteria entering through a skin wound, or through hematogenous spread when there is a severe underlying condition such as a general condition disorder or immunodeficiency. It requires hypervigilance during the examination and throughout the treatment course with intravenous antibiotic therapy and urgent surgical drainage, as it may cause significant complications regarding localization, lymphovascular drainage, and ultimate spread. Persistent abscess, necrotic tissue, or cavitated lesions are worrisome and it is important to rule out immunosuppression or a methicillin-resistant staphylococcus. In this case, a 22-year-old male patient with a unilateral lip abscess, misdiagnosed as an allergic food reaction, responded well to external drainage and antibiotic therapy.

How Should Complicated Cases of Thrombotic Thrombocytopenic Purpura With Positive Coombs Test Be Treated?

Thrombocytopenia with concomitant anemia is a serious condition with a high mortality risk. Destruction of platelets, i.e., thrombocytopenia, can be secondary to either auto-antibodies (immune-mediated) or mechanical destruction (non-immune-mediated). The Coombs test is a widespread tool to differentiate between the two categories, resulting in different specific treatment approaches for each diagnosis. A peripheral blood smear can also help make the diagnosis; for instance, in cases of mechanical destruction such as thrombotic thrombocytopenic purpura (TTP), the red blood cell (RBC) shape looks fragmented, forming schistocytes. In rare instances, TTP can present with both schistocytes and a positive Coombs test, challenging the diagnosis of TTP. TTP is a hematological emergency requiring appropriate anticipation and the initiation of treatment prior to the confirmatory ADAMTS-13 test results. Mild forms of TTP can be managed with glucocorticoids and therapeutic plasma exchange. Refractory cases need more aggressive additional treatment with caplacizumab and rituximab. Caplacizumab is an expensive medication that is usually reserved for use after confirmation of a TTP diagnosis. The advantage of caplacizumab lies in its targeted mechanism of action against the A1 domain of the von Willebrand multimers that are normally destructed by the ADAMTS-13 enzyme. Here, we present a young female patient with confirmed TTP, and the initial diagnosis was challenged by the presence of antibodies with the Coombs test. Very little research has studied this rare instance and the appropriate treatment. Our case will save many future lives, as clinicians should be more aggressive in treating refractory TTP with a positive Coombs test.

Streptococcus intermedius: From a Normal Oral Commensal to a Life-Threatening Organism.

Subdural empyema is a collection of pus in the subdural space between the dura mater and the arachnoid. It carries very high morbidity and mortality as it can spread anywhere in the brain; however, the risk can be mitigated with appropriate surgical and medical intervention. Being protected by the skull, cranial infections are usually preceded by a significant risk factor, either an external invader such as skull fractures secondary to trauma, penetrating injury, prior surgery, or, more commonly, in more than 50% of cases, due to spread of an internal infection such as ear or sinus infections. Anaerobic and aerobic bacteria can cause subdural empyema. Both gram-positive and gram-negative bacteria are notorious for developing this kind of infection; for example, different groups of gram-positive streptococci and staphylococci, gram-negative Haemophilus influenza, and other gram-negative bacilli can cause subdural empyema. While streptococci are more frequent with sinus infection causing subdural empyema, staphylococci are associated with skin invasion secondary to either head trauma or cranial surgery. Streptococcus intermedius is a gram-positive alpha-hemolytic pathogen belonging to the larger Streptococcus anginosus group that itself is a subgroup from viridans streptococci, aka Streptococcus milleri. Streptococcus intermedius is an oral commensal flora and is considered to be a low-virulence bacteria in immunocompetent patients but can be associated with significant morbidity and mortality. Subdural empyema tends to occur more often in immunocompromised patients such as diabetic patients, those with human immunodeficiency virus infection, and those using immunosuppressive medications. The clinical course ranges from indolent to fulminant. The size and location of the abscess play a role in clinical presentation. Headache is the most common presenting symptom, but patients can also present with fever, nausea, seizure, or altered mental status. Diagnosis can be obtained with CT and MRI scans of the brain. Prompt drainage of the abscess and lengthy antibiotics improve the prognosis significantly. Our case highlights a rare origin of subdural empyema from the direct spread of a skin abscess.

The unpredictability of labile blood pressure: Afferent baroreflex failure in a critical patient with multiple thyroid surgeries and COVID-19 infection.

The carotid sinus-arterial baroreflex is essential in maintaining blood pressure (BP) regulation. Afferent baroreflex failure (ABF) can present with labile changes in BP within seconds and can be secondary to neck surgery or radiation. We present here the first case, to our knowledge, of ABF precipitated by thyroidectomy, in a patient with active COVID-19 pneumonia, causing difficult control of severely labile BP in a critical care unit. Contributing factors included her critical illness state with upregulation of IL-6 leading to pituitary-adrenal axis alteration, her thyroidectomy further exacerbating autonomic dysfunction, as well as downregulation of ACE2 via COVID-19 infection. Management was achieved with a combination of midodrine and clonidine catered to specific BP thresholds. Additional research with a multidisciplinary approach is warranted to fully optimize the treatment of ABF in patients with neck surgery and or inflammatory conditions such as COVID-19.