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Acute fatal ventricular arrhythmia induced by severe hyperkalemia in a toddler with decompensated methylmalonic acidemia. J Med Case Rep 2024; 18:73. [PMID: 38395924 PMCID: PMC10893669 DOI: 10.1186/s13256-024-04406-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 01/22/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND Methylmalonic acidemia is a very rare genetic metabolic disease. Patients with isolated methylmalonic acidemia typically present with acute alterations of consciousness, failure to thrive, anorexia, vomiting, respiratory distress, and muscular hypotonia. Despite the evidence-based management, affected individuals experience significant morbidity and mortality. Hyperkalemia is one of the unusual complications of methylmalonic acidemia. CASE PRESENTATION In this paper, we describe a 4-year-old Persian boy with methylmalonic acidemia who developed life-threatening arrhythmia following severe hyperkalemia and metabolic acidosis. Emergent management of the condition was successfully carried out, and the rhythm changed to normal sinus rhythm by effectively reducing the serum potassium level. We discuss the possible etiology of this lethal condition and describe its management on the basis of the available evidence. CONCLUSION During metabolic decompensation in methylmalonic acidemia, frequent blood gas and electrolyte testing to prescribe and adjust therapy and annual echocardiogram and electrocardiogram screening are essential.
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Bochdalek hernia presenting as recurrent fever and bicytopenia in a pediatric patient: A rare case report. Clin Case Rep 2023; 11:e8039. [PMID: 37830069 PMCID: PMC10565089 DOI: 10.1002/ccr3.8039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/14/2023] Open
Abstract
Bochdalek hernia is a rare condition characterized by the displacement of abdominal contents into the thoracic cavity. Due to the nonspecific nature of symptoms, prompt diagnosis, and management by emergency care providers can be challenging. Treatment of a Bochdalek hernia typically involves the reduction in the herniated contents back into the abdominal cavity. In this case report, we present the case of a 1-year-old girl who presented to the emergency department with a fever and bicytopenia. Further evaluation revealed a Bochdalek hernia, which was successfully managed with surgical intervention. This case highlights the importance of considering a Bochdalek hernia in the differential diagnosis of patients presenting with recurrent nonspecific symptoms (fever and bicytopenia).
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Adolescence Onset Primary Coenzyme Q10 Deficiency With Rare CoQ8A Gene Mutation: A Case Report and Review of Literature. CLINICAL MEDICINE INSIGHTS-CASE REPORTS 2023; 16:11795476231188061. [PMID: 37476682 PMCID: PMC10354825 DOI: 10.1177/11795476231188061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 06/25/2023] [Indexed: 07/22/2023]
Abstract
Background Primary deficiency of coenzyme Q10 deficiency-4 (CoQ10D4) is a heterogeneous disorder affecting different age groups. The main clinical manifestation consists of cerebellar ataxia, exercise intolerance, and dystonia. Case report We provide a case of adolescence-onset ataxia, head tremor, and proximal muscle weakness accompanied by psychiatric features and abnormal serum urea (49.4 mg/dL), lactate (7.5 mmol/L), and CoQ10 level (0.4 µg/mL). Brain-MRI demonstrated cerebellar atrophy, thinning of the corpus callosum, and loss of white matter. Whole exome sequencing showed a homozygous missense mutation (c.911C>T; p.A304V) in CoQ8A gene which is a rare mutation and responsible variant of CoQ10D4. After supplementary treatment with CoQ10 50 mg/twice a day for 2 months the clinical symptoms improved. Conclusion These observations highlight the significance of the early diagnosis of potentially treatable CoQ8A mutation as well as patient education and follow-up. Our findings widen the spectrum of CoQ8A phenotypic features so that clinicians be familiar with the disease not only in severe childhood-onset ataxia but also in adolescence with accompanying psychiatric problems.
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An HIV-positive woman with massive brain lesion due to toxoplasmosis: A case report. Clin Case Rep 2023; 11:e7688. [PMID: 37457995 PMCID: PMC10340077 DOI: 10.1002/ccr3.7688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/07/2023] [Accepted: 06/13/2023] [Indexed: 07/18/2023] Open
Abstract
Key Clinical Message Toxoplasmosis-related huge brain lesions may require decompressive craniectomy and lesion excision to avoid brain damage. In this situation, injectable cotrimoxazole is a better choice for treatment. Abstract Toxoplasma gondii is a worldly distributed obligate intracellular protozoa. Toxoplasmosis is a prevalent opportunistic infection in HIV-infected people, but it was rarely recorded prior to the identification of HIV infection. Here, we report a toxoplasmosis brain lesion in an Iranian HIV-positive patient. A 45-year-old woman with a complaint of malaise was referred to the Valiasr Hospital in Arak city. In her past clinical history, the patient had a history of anemia, deep vein thrombosis (DVT), and positive HIV. The patient was informed of the diagnosis of massive brain toxoplasmosis as a definite diagnosis. The patient was then taken to the operating room for a left decompressive craniectomy, during which the ensuing brain lesion was excised. After a few days, she was discharged from the hospital in good condition and without any complications.
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HAV-induced acalculous cholecystitis: A case report and literature review. Clin Case Rep 2023; 11:e7254. [PMID: 37113636 PMCID: PMC10127462 DOI: 10.1002/ccr3.7254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 04/02/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Hepatitis A virus (HAV) has some life-threatening extrahepatic complications, such as acute acalculous cholecystitis (AAC). We present HAV-induced AAC in a young female, based on clinical, laboratory, and imaging findings, and conduct a literature review. The patient became irritable, which progressed to lethargy, as well as a significant decline in liver function, indicating acute liver failure (ALF). She was immediately managed in the intensive care unit with close airway and hemodynamic monitoring after being diagnosed with ALF (ICU). The patient's condition was improving, despite only close monitoring and supportive treatment with ursodeoxycholic acid (UDCA) and N-acetyl cysteine (NAC).
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A novel variant of Paganini-Miozzo syndrome: a case report. Oxf Med Case Reports 2023; 2023:omad024. [PMID: 36993824 PMCID: PMC10041959 DOI: 10.1093/omcr/omad024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/26/2023] [Accepted: 02/28/2023] [Indexed: 03/29/2023] Open
Abstract
Paganini-Miozzo syndrome (MRXSPM) is a rare neurogenetic disorder that is transmitted by X-linked recessive inheritance. This is the third case reported of this disease in the world with a novel variant. A boy was referred due to the absence of neck holding and hand tremors. The examinations found facial anomalies. The brain magnetic resonance imaging (MRI) showed cerebral atrophy and diffused white matter, and irregularities were seen in his electroencephalogram (EEG). The echocardiography revealed a mid-muscular ventricular septal defect. A whole exome sequencing (WES) analysis revealed a novel variant (c.979C > T; p.Pro327Ser) of uncertain significance in the HS6ST2 gene indicating Paganini-Miozzo syndrome. The current case provides additional evidence that MRXSPM can be associated with various neurological and cardiac complications. It is essential to rule out other causes, such as metabolic and infectious diseases. EEG, MRI and WES analyses can help to make a definitive diagnosis.
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An unusual case of a toddler with Canavan disease with frequent
intractable seizures: A case report and review of the literature. SAGE Open Med Case Rep 2023; 11:2050313X231160885. [PMID: 36968992 PMCID: PMC10034305 DOI: 10.1177/2050313x231160885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/10/2023] [Indexed: 03/24/2023] Open
Abstract
Canavan disease is a rare fetal inherited leukodystrophy, caused by accumulation
of N-acetyl-aspartate in the brain. Here, we report a child presented with
frequent intractable seizures and visual impairment. A 14-month-old female
infant with a complaint of the absence of neck holding and generalized
tonic-clonic seizures was referred to our hospital. Macrocephaly, setting sun
eyes, tremor, and hypotonia were observed. Funduscopy showed optic atrophy. Our
patient’s flash visual evoked potential showed blindness. Her brain magnetic
resonance imaging showed diffuse white matter in subcortical, basal ganglia, and
dorsal pons. Electroencephalography showed diffuse slow and sharp waves. The
genetic study detected a hemizygous mutation in the aspartoacylase gene. Our
patient was diagnosed with Canavan disease and began anticonvulsant treatment.
However, seizures were not under control. Then, her medications were
discontinued, and clobazam and primidone were administered. In conclusion,
starting clobazam and primidone may help prevent frequently intractable seizures
in Canavan disease patients.
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Streptococcus Viridans meningitis in an immunocompetent child: A case report. Clin Case Rep 2023; 11:e7058. [PMID: 36911641 PMCID: PMC9994428 DOI: 10.1002/ccr3.7058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 01/25/2023] [Accepted: 02/20/2023] [Indexed: 03/10/2023] Open
Abstract
In bacterial meningitis, the Viridans streptococci group is not considered a prevalent pathogen. In contrast, the S. viridans group may cause endocarditis and fatal infections in immunocompromised children and adults. We report a 5-year-old immunocompetent boy with signs of meningitis. The CSF tested positive for meningitis with streptococcus viridans.
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A Rare Case of Cerebrotendinous Xanthomatosis Associated With a Mutation on COG8 Gene. J Investig Med High Impact Case Rep 2023; 11:23247096231168109. [PMID: 37083278 PMCID: PMC10126670 DOI: 10.1177/23247096231168109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023] Open
Abstract
Cerebrotendinous xanthomatosis (CTX) is a rare hereditary disease described by a mutation in the CYP27A1 gene, which encodes the sterol 27-hydroxylase enzyme involved in the synthesis of bile acid. Accumulation of cholesterol and its metabolite, cholestanol, in multiple body organs causes the symptoms of this disease. In addition, a mutation in the COG8 gene, which encodes a subunit of conserved oligomeric Golgi (COG) complex, causes another rare disorder attributed to type IIh of congenital disorder of glycosylation (CDG). We described a rare case of CTX disorder associated with a mutation on COG8 gene, which presented by unusual symptoms.
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A rare case of an immunocompetent patient with isolated pulmonary mucormycosis. IDCases 2023; 31:e01726. [PMID: 36923658 PMCID: PMC10009052 DOI: 10.1016/j.idcr.2023.e01726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/16/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
As one of the most lethal infections caused by fungi, pulmonary mucormycosis usually affects patients who are immunocompromised. Isolated pulmonary mucormycosis in immunocompetent patients is very rare.This report describes a 65-year-old immunocompetent man, who was first treated with antibiotics after being diagnosed with a lung infection, then after the lack of response to treatment, he was diagnosed with mucormycosis in further investigations. Finally, the patient died due to a lack of response to treatment. Despite its rarity, it is important to consider other differential diagnoses such as pulmonary mucormycosis if the pneumonic process does not respond to medical treatment.
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Urinary tract infection caused by Edwardsiella tarda: a report of the first case in Iran. BMC Infect Dis 2022; 22:962. [PMID: 36577951 PMCID: PMC9798618 DOI: 10.1186/s12879-022-07960-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 12/19/2022] [Indexed: 12/29/2022] Open
Abstract
BCKGROUND Edwardsiella tarda, an Enterobacteriaceae family member, is prevalent in different aquatic settings and rarely infects humans. As a result of eating raw or undercooked seafood, humans become infected through their intestinal tracts. Extraintestinal infections have been reported infrequently, mostly in immunocompromised and chronically ill patients. CASE PRESENTATION Our report describes a case of urinary tract infection caused by E. tarda in a 4-year-old female patient with a history of urinary tract infection and a complaint of fever, dysuria, and frequency. E. tarda was identified as the pathogen isolated from the urine culture. The patient's symptoms were alleviated after receiving ceftriaxone and then nitrofurantoin. CONCLUSION This case demonstrates that even in immunocompetent patients, E. tarda can infect extraintestinal organs, including urinary tract. Our patient represents the first case of E. tarda infection in Iran and due to the fact that this pathogen is transmitted by aquatic animals, there is a possibility of infecting more aquatic animals and humans in Iran; therefore, the necessary precautions should be taken.
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Cerebrovascular accident in a child with precursor B-cell acute lymphoblastic leukemia and coronavirus disease 2019: a case report. J Med Case Rep 2022; 16:452. [PMID: 36471442 PMCID: PMC9724282 DOI: 10.1186/s13256-022-03672-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 11/07/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Coronavirus disease 2019 can lead to rare but severe and life-threatening diseases in susceptible high-risk populations, including patients with immunodeficiency. A rare event in this report is stroke following COVID-19 disease in a patient with an immunocompromised background due to leukemia and anti-cancer treatments. CASE PRESENTATION A 6-year-old iranian girl with precursor B-cell leukemia receiving vincristine therapy presented with fever and absolute neutrophil count < 500. Her severe acute respiratory syndrome coronavirus 2 polymerase chain reaction test was positive. During hospitalization, she had abrupt onset tachypnea, reduced O2 saturation, and generalized tonic-clonic seizures treated with phenytoin and levetiracetam. Right parietal lobe ischemia was found on a brain computed tomography scan, and the cerebrospinal fluid polymerase chain reaction test was positive for severe acute respiratory syndrome coronavirus 2. Several days later, she developed lower extremity paralysis and speech impairment, so speech therapy and physiotherapy were initiated. The patient also received dexamethasone, mannitol, heparin, and remdesivir. She was discharged with enoxaparin and levetiracetam. Chemotherapy resumed 2 weeks following discharge. Her speech and walking improved after 10 months of follow-up, and bone marrow aspiration showed total remission. CONCLUSION Owing to the link between coronavirus disease 2019 and hematologic cancers with hypercoagulopathy and the tendency of patients with leukemia to have coronavirus disease 2019 complications, children with leukemia as well as suspected coronavirus disease 2019 must be hospitalized to prevent blood clot formation.
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Isolated psoas abscess caused by
Mycobacterium tuberculosis
: A rare case report. Clin Case Rep 2022; 10:e05823. [PMID: 35664522 PMCID: PMC9136494 DOI: 10.1002/ccr3.5823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/03/2022] [Accepted: 04/10/2022] [Indexed: 11/19/2022] Open
Abstract
Psoas tuberculosis abscess is very rarely detected primarily without an adjacent vertebral cold abscess. Early diagnosis prevents unnecessary operations and life‐threatening complications.
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Histopathologic features of nasal glial heterotopia (nasal glioma). Childs Nerv Syst 2022; 38:63-75. [PMID: 34562130 DOI: 10.1007/s00381-021-05369-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/19/2021] [Indexed: 11/24/2022]
Abstract
PURPOSE Nasal glioneuronal heterotopia (NGH) is an uncommon developmental abnormality of the nasal cavity or paranasal soft tissue. Few detailed histologic studies of NGH exist, and molecular analyses have not been performed to date. METHODS We describe six cases of pediatric NGH and two representative encephaloceles encountered in our practice over the past 20 years. RESULTS Two clinically distinct patient groups were noted, those with 1) intranasal nasal cavity mass (n = 3), or 2) extranasal cutaneous mass on the nose (n = 3, 1 on nasal apex, 2 on nasal bridge). Intranasal cases presented within the first week of life, whereas the extranasal NGH presented at ages of 4, 7, and 8 months. Resection was curative in 5/6 cases, with a single case showing local recurrence. Histologic examination showed a predominantly glial cell composition, with nests of GFAP-immunoreactive neuropil containing large, often multinucleated astrocytes. Neurons, although difficult to identify on H&E-stains, were readily observed in all cases by NeuN-immunostain. At least focal leptomeninges were noted in 2/3 intranasal and 1/3 extranasal NGHs on routine histology, SSTR2A immunohistochemistry further confirmed leptomeninges/ arachnoid cells in 4/6 cases. 1 of 4 NGH (extranasal) cases showed copy number variations in chromosome 16, 17 and 19, which were also present in 1/2 encephalocele cases. The full significance of these alterations remains unknown. CONCLUSION We find evidence of histologic overlap between NGH and encephalocele, and, for the first time, report molecular alterations shared between the two entities, suggesting that these conditions may represent spectrum of the same histopathologic entity.
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Effect of Educational Program on Pressure Ulcer Prevention Intervention among Nurses of Intensive Care Units at a Public Hospital, Pakistan. CLINICAL SOCIAL WORK AND HEALTH INTERVENTION 2020. [DOI: 10.22359/cswhi_11_4_05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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NONINVASIVE CARDIAC OUTPUT MONITORING (NICOM) VS CAVAL INDEX ULTRASONOGRAPHY: A PROSPECTIVE COMPARISON TO PREDICT FLUID RESPONSIVENESS IN PATIENTS WITH SEPSIS. Chest 2019. [DOI: 10.1016/j.chest.2019.02.114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Investigating the factors affecting the disclosure of intellectual capital in companies listed on the Tehran stock exchange. MARKETING AND MANAGEMENT OF INNOVATIONS 2017. [DOI: 10.21272/mmi.2017.1-25] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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The knowledge and perceptions regarding the role of family physicians
among patients in primary care clinics in Nairobi. Ann Glob Health 2016. [DOI: 10.1016/j.aogh.2016.04.312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Pharmacological management of chronic neuropathic pain - consensus statement and guidelines from the Canadian Pain Society. Pain Res Manag 2007; 12:13-21. [PMID: 17372630 PMCID: PMC2670721 DOI: 10.1155/2007/730785] [Citation(s) in RCA: 345] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Neuropathic pain (NeP), generated by disorders of the peripheral and central nervous system, can be particularly severe and disabling. Prevalence estimates indicate that 2% to 3% of the population in the developed world suffer from NeP, which suggests that up to one million Canadians have this disabling condition. Evidence-based guidelines for the pharmacological management of NeP are therefore urgently needed. Randomized, controlled trials, systematic reviews and existing guidelines focusing on the pharmacological management of NeP were evaluated at a consensus meeting. Medications are recommended in the guidelines if their analgesic efficacy was supported by at least one methodologically sound, randomized, controlled trial showing significant benefit relative to placebo or another relevant control group. Recommendations for treatment are based on degree of evidence of analgesic efficacy, safety, ease of use and cost-effectiveness. Analgesic agents recommended for first-line treatments are certain antidepressants (tricyclics) and anticonvulsants (gabapentin and pregabalin). Second-line treatments recommended are serotonin noradrenaline reuptake inhibitors and topical lidocaine. Tramadol and controlled-release opioid analgesics are recommended as third-line treatments for moderate to severe pain. Recommended fourth-line treatments include cannabinoids, methadone and anticonvulsants with lesser evidence of efficacy, such as lamotrigine, topiramate and valproic acid. Treatment must be individualized for each patient based on efficacy, side-effect profile and drug accessibility, including cost. Further studies are required to examine head-to-head comparisons among analgesics, combinations of analgesics, long-term outcomes, and treatment of pediatric and central NeP.
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Aortic reconstruction in the HIV infected patient. JOURNAL OF MEDICINE 2001; 30:122-6. [PMID: 10515248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Major vascular reconstruction using prosthetic implantation is uncommon in the HIV infected patient. We describe a 52-year-old man with HIV infection and HIV-induced thrombocytopenia, who underwent successful aorto-bifemoral bypass for lower extremity ischemic symptoms. Postoperative progressive thrombocytopenia and subsequent hemorrhage were successfully treated with intravenous steroid replacement, platelet transfusion, alpha-globulin administration and expectant management. This report serves to illustrate that major vascular reconstruction can be successfully accomplished in the HIV infected population, even in the presence of significant hematologic dysfunction.
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22
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Isolation of antihypertensive alkaloids from the rhizomes of Veratrum album. PLANTA MEDICA 1993; 59:569-571. [PMID: 8302959 DOI: 10.1055/s-2006-959767] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Abstract
Using tetradecanoylphorbol 13-acetate (TPA), a known inducer of epithelial cell differentiation, and Northern blot analysis, we investigated in normal versus well-differentiated malignant keratinocytes the modulation of genes implicated in their growth or differentiated function. In normal keratinocytes transient c-fos induction was detected within 30 min after stimulation and was followed by rapid down regulation of the proto-oncogenes c-myc and epidermal growth factor receptor. Within hours after stimulation mRNA levels for three well-characterized differentiated keratinocyte products, involucrin, interleukin-1 beta (IL1-beta), and fibronectin, were induced, as were those for a growth arrest and DNA damage-inducible (GADD 153) gene and a small proline-rich (SPR1) gene, both known to be associated with differentiation but with of as yet unknown functions. Heat shock protein 70 gene was initially down regulated and was induced only after 48 h. The well-differentiated malignant keratinocyte cell line differed in that the c-fos, GADD, SPR1, and IL1-beta genes had several-fold higher induction, but involucrin mRNA was undetectable and fibronectin mRNA was only minimally induced after TPA stimulation. Malignant cells reached terminal differentiation faster than normal keratinocytes as measured by inability to exclude trypan blue dye, and in situ hybridization using a riboprobe for the differentiation-associated SPR1 gene showed that normal keratinocytes constitutively express this transcript while malignant keratinocytes with virtually identical morphology and growth rate do not. These studies greatly expand our understanding of gene activation and down regulation during normal keratinocyte differentiation and imply that a malignant cell line, even when retaining the phenotype of normal cells, differs in its response to outside stimuli, furnishing at best an imperfect model for investigating the molecular mechanisms of cellular differentiation.
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Supplement II: Abstracts of the international symposium on Skin Carcinogenesis in man and in experimental models. Heidelberg, 29–31 October 1991 (pp S61–S88). J Cancer Res Clin Oncol 1991. [DOI: 10.1007/bf01613300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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