Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344232 (blurred vision)
 2,072 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The first pyrethroid pesticide, allethrin, was identified in 1949. Allethrin and other pyrethroids with a basic cyclopropane carboxylic ester structure are type I pyrethroids. The insecticidal activity of these synthetic pyrethroids was enhanced further by the addition of a cyano group to give alpha-cyano (type II) pyrethroids, such as cypermethrin. The finding of insecticidal activity in a group of phenylacetic 3-phenoxybenzyl esters, which lacked the cyclopropane ring but contained the alpha-cyano group (and hence were type II pyrethroids) led to the development of fenvalerate and related compounds. All pyrethroids can exist as at least four stereoisomers, each with different biological activities. They are marketed as racemic mixtures or as single isomers. In commercial formulations, the activity of pyrethroids is usually enhanced by the addition of a synergist such as piperonyl butoxide, which inhibits metabolic degradation of the active ingredient. Pyrethroids are used widely as insecticides both in the home and commercially, and in medicine for the topical treatment of scabies and headlice. In tropical countries mosquito nets are commonly soaked in solutions of deltamethrin as part of antimalarial strategies. Pyrethroids are some 2250 times more toxic to insects than mammals because insects have increased sodium channel sensitivity, smaller body size and lower body temperature. In addition, mammals are protected by poor dermal absorption and rapid metabolism to non-toxic metabolites. The mechanisms by which pyrethroids alone are toxic are complex and become more complicated when they are co-formulated with either piperonyl butoxide or an organophosphorus insecticide, or both, as these compounds inhibit pyrethroid metabolism. The main effects of pyrethroids are on sodium and chloride channels. Pyrethroids modify the gating characteristics of voltage-sensitive sodium channels to delay their closure. A protracted sodium influx (referred to as a sodium 'tail current') ensues which, if it is sufficiently large and/or long, lowers the action potential threshold and causes repetitive firing; this may be the mechanism causing paraesthesiae. At high pyrethroid concentrations, the sodium tail current may be sufficiently great to prevent further action potential generation and 'conduction block' ensues. Only low pyrethroid concentrations are necessary to modify sensory neurone function. Type II pyrethroids also decrease chloride currents through voltage-dependent chloride channels and this action probably contributes the most to the features of poisoning with type II pyrethroids. At relatively high concentrations, pyrethroids can also act on GABA-gated chloride channels, which may be responsible for the seizures seen with severe type II poisoning. Despite their extensive world-wide use, there are relatively few reports of human pyrethroid poisoning. Less than ten deaths have been reported from ingestion or following occupational exposure. Occupationally, the main route of pyrethroid absorption is through the skin. Inhalation is much less important but increases when pyrethroids are used in confined spaces. The main adverse effect of dermal exposure is paraesthesiae, presumably due to hyperactivity of cutaneous sensory nerve fibres. The face is affected most commonly and the paraesthesiae are exacerbated by sensory stimulation such as heat, sunlight, scratching, sweating or the application of water. Pyrethroid ingestion gives rise within minutes to a sore throat, nausea, vomiting and abdominal pain. There may be mouth ulceration, increased secretions and/or dysphagia. Systemic effects occur 4-48 hours after exposure. Dizziness, headache and fatigue are common, and palpitations, chest tightness and blurred vision less frequent. Coma and convulsions are the principal life-threatening features. Most patients recover within 6 days, although there were seven fatalities among 573 cases in one series and one among 48 cases in another. Management is supportive. As paraesthesiae usually resolve in 12-24 hours, specific treatment is not generally required, although topical application of dl-alpha tocopherol acetate (vitamin E) may reduce their severity.
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PMID:Poisoning due to pyrethroids. 1618 Sep 29

Depression is among the most common of chronic health problems. WHO report predicts that depression will be the leading cause of disability in the industrial world by the year 2020. To be successful, treatment for the patients suffering from depression must be continued until complete recovery, but most patients do not stay on their antidepressant medication long enough. One of the most frequent reasons for break down is appearance of unpleasant side effects. In this study we followed up dynamics of the characteristic side effects of antidepressant therapy, with the major goal to assess their frequency and characteristics. The sample was all female patients taking antidepressant drugs in the Department of Psychiatry of Clinical Centre of University in Sarajevo. The treatment with antidepressants was efficient in most of the patients. A major advantage of SSRI over TCA was less pronounced side effects. The most intensive side effects of TCA (amitriptyline) were dry mouth, tremor and tachycardia while the most frequent side effects included blurred vision, tachycardia, dry mouth, tremor and sedation. Side effects of SSRI (fluoxetine/fluvoxamine) were mild, and the most frequent were nausea, tachycardia, swelling, dry mouth.
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PMID:Frequency and characteristics of side effects associated with antidepressant drugs. 1621 60

Accidental or intentional ingestion of carbofuran can produce a life-threatening syndrome that requires prompt diagnosis and treatment. This paper investigates unintentional carbofuran poisoning in farm workers. Thirteen patients were admitted to the emergency department with carbofuran poisoning between January 2002 and August 2004 (2 female, 11 male). The patients had been poisoned while mixing the liquid form of carbofuran with seeds. Their hands were red on admission. Complaints most commonly reported by the patients on admission were nausea, vomiting, headache, weakness, dizziness and blurred vision. The most commonly observed signs were tachycardia, tachypnea, salivation, miosis, elevated blood pressure, and fasciculation. Three patients were agitated and one was lethargic on admission. We reviewed the patients' medical charts retrospectively, as well as the demographic data, intoxication route, clinical and laboratory presentations, and outcomes. We made the diagnosis according to a compatible exposure history and clinical findings. The most commonly observed laboratory finding was hyperglycemia, which was found in 6 patients. Serum pseudocholinesterase level was low in only one patient. All the patients were cured and discharged from the hospital in good physical condition. Rapid onset, mild illness and quick recovery are typical characteristics of acute occupational carbofuran poisoning. We conclude that public health efforts should educate farm workers about the dangers of pesticide application so that its threat can be diminished.
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PMID:Carbofuran poisoning among farm workers. 1635 64

Concussions remain one of the most troublesome injuries sports physicians face. Studies suggest recovery takes hours to weeks, but at what point is the concussed brain no longer at increased risk for reinjury is unknown. Physicians must be alert to the symptoms of concussion and be familiar with the available tools to assess neurocognitive dysfunction. Prospectively validated signs and symptoms include amnesia, loss of consciousness, headache, dizziness, blurred vision, attention deficit, memory, postural instability, and nausea. A player with any signs or symptoms of a concussion should not be allowed to return to the current game or practice and should be monitored closely for deterioration of symptoms. Return-to-play should be individually based and proceed in a step-wise manner. The ongoing risk-benefit analysis of return-to-play must currently be based on experience, corollary data from traumatic brain injuries in animals and humans, and limited prospective data with sports-related concussions.
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PMID:Sideline management of sport-related concussions. 1713 69

We report two cases of spotted black snake (Pseudechis guttatus) envenoming. One patient experienced localised burning pain around the bite and developed nausea, vomiting, diarrhoea, upper abdominal cramping and diaphoresis. He was treated with intravenous fluids and antiemetics, but no antivenom, and was discharged 23 hours after the bite. The second patient developed a severe headache, blurred vision and mild nausea, associated with severe pain and swelling of the bitten limb that took 4 days to resolve. No antivenom was given and the patient had no sequelae. Neither patient developed significant coagulopathy, myolysis or neuromuscular paralysis. Bites by this species appear to cause effects similar to those of the more common red-bellied black snake (P. porphyriacus).
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PMID:Spotted black snake (Pseudechis guttatus) envenoming. 1722 34

Headache is the cardinal symptom of acute mountain sickness (AMS). The headache normally worsens, with increased cerebral affection and the development of high-altitude cerebral edema (HACE). A Norwegian expedition aimed to climb Baruntse (7129 m) in Nepal in 2003. At 5400 m a 35-year-old man felt exhausted. The next day he aborted his attempt at further climbing as a result of extreme fatigue. Over the next 24 hours he developed cough, dyspnea, and severe hypoxia before progressing to ataxia and blurred vision. At no point did he experience headache or nausea. The patient was evacuated by helicopter. He improved immediately after descent and recovered completely within a week. The speed of progression from AMS to HACE varies. Abrupt onset of HACE is occasionally reported. High-altitude pulmonary edema (HAPE) may induce severe hypoxia that can lead to rapid development of HACE. High-altitude cerebral edema in the setting of HAPE was the most likely diagnosis despite the unusual lack of headache. Rapid onset of HAPE with subsequent severe desaturation should raise awareness of the development of HACE, even in the absence of headache.
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PMID:High-altitude cerebral edema with absence of headache. 1744 14

We report a case of aseptic meningitis thought to be associated with chronic sulindac use in a patient with osteoarthritis. The patient was hospitalized with an acute onset of headache, nuchal rigidity, nausea, and blurred vision. Brain imaging was unremarkable and a lumbar puncture revealed a lymphocytic pleocytosis. No infectious source was identified. The patient reported taking sulindac over the past year, it was discontinued, and symptoms promptly resolved. This case underscores the importance of obtaining a thorough drug history in conjunction with the knowledge of causative medications associated with aseptic meningitis. Given the widespread use of nonsteroidal anti-inflammatory drugs, clinicians must recognize that aseptic meningitis is a possible adverse effect of these medications.
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PMID:Aseptic meningitis associated with chronic sulindac use for osteoarthritis: a case report. 1770 6

Diabetes mellitus develops in about 10% of acromegalic patients, usually secondary to insulin resistance caused by growth hormone excess. Diabetic ketoacidosis is a result of relative insulin deficiency and is a rare feature of acromegaly. Here, we present one case of this disorder. A 57-year-old man came to the emergency room due to 2 weeks of dizziness. He also had polyuria, polydipsia, nausea, diplopia, blurred vision and dysarthria. His plasma glucose level was 32.06 mmol/L, plasma osmolarity was 322 mOsm/L, arterial pH was 7.30, level of bicarbonates was 18 mmol/L, urine ketones was 4+, and HbA1c was 14.1%. No specific cause for the development of this metabolic derangement could be found. He displayed clinical features of acromegaly during admission, which was confirmed by an elevated growth hormone level and pituitary macroadenoma shown on magnetic resonance imaging. The patient underwent total transsphenoid tumor removal 2 weeks later; plasma glucose levels became normal thereafter.
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PMID:Diabetic ketoacidosis in a patient with acromegaly. 1790 70

Enhanced sympathetic activity causes an exaggerated heart rate response to standing in the postural tachycardia syndrome (POTS). All patients describe symptoms of orthostatic intolerance such as dizziness, blurred vision, shortness of breath, palpitations, tremulousness, chest discomfort, headache, lightheadedness and nausea, but only one third suffer loss of consciousness. We report four patients with POTS, who had long ventricular pauses (i.e. asystole) and syncope during head-up tilt test. This suggests that a subset of patients with POTS can have a surge in parasympathetic outflow that precedes vasovagal syncope.
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PMID:Postural tachycardia syndrome with asystole on head-up tilt. 1795 28

A 24-year-old Vietnamese woman presented with a 3-month history of non-itchy erythematous plaques on the face, trunk and limbs. Borderline lepromatous leprosy was confirmed by clinical findings, acid-fast bacilli on skin biopsy specimen and skin smear and a history of exposure. Around the twentieth day of World Health Organization (WHO) multibacillary standard treatment (rifampin 600 mg per month, dapsone 100 mg per day, clofazimine 300 mg per month and 50 mg per day for 1 year), she developed fever, general malaise, blurred vision, cough, nausea, epigastric pain, and arthralgia. The skin lesions also became swollen. During hospitalization, her illness was complicated by retrobulbar optic neuritis, secondary bacterial pneumonia, pleuritis, ascites, hepatitis, antral gastritis, progressive normocytic anemia, and peripheral sensory loss. The patient recovered after receiving systemic steroid pulse therapy (prednisolone equivalent dose 1250 mg) with systemic antibiotics (cefuroxime), adjustment of her anti-lepromatous therapy, and supportive care. She resumed the WHO multibacillary regimen uneventfully. This patient presented with a diverse type 1 reaction, which is a complex immune response in leprosy. We found that the judicious use of high dose steroids followed by a slow tapering course is beneficial in managing patients with a severe type 1 reaction. At the 1-year follow up, the patient had generalized skin hyperpigmentation resulted from long-term clofazamine use and numbness on feet without other systemic sequelae.
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PMID:Corticosteroid pulse therapy for leprosy complicated by a severe type 1 reaction. 1856 21


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