Transient Monocular Visual Loss (Amaurosis Fugax): How Does Age Impact Diagnosis?

Transient monocular visual loss (TMVL), also known as transient monocular blindness or amaurosis fugax ("fleeting blindness"), is a temporary loss of vision often due to ischemia to the retina. While acute TMVL should be considered an emergency that further requires exhaustive investigation, there are some cases in which TMVL arises secondary to benign causes. Age has a major impact in the diagnosis of ischemia and although the differential diagnosis of TMVL can be broad, timely and appropriate history, examination, diagnostic testing, and treatment can be vision- or life-saving. We review the causes of TMVL and the impact of age on the differential diagnoses and management.

A simple and rapid genotyping method for beta-2 receptor (beta2 AR) gene using allele specific multiplex PCR.

BACKGROUND: Polymorphism of the beta2-adrenergic receptor (beta2 AR) gene is an important determinant of the function of this receptor. It affects receptor down-regulation and beta2-agonist responses. It has also been a focus of interest in attempts to elucidate the genetic basis of asthma, hypertension, obesity and cystic fibrosis. Several different techniques have been established to determine beta2 AR genotypes but none of these methods are simple enough to detect simultaneously all the five alleles of our research interest (Arg16/Gly16, -20T/C, Gln27/Glu27, -47T/C and Thr164/Ile164). OBJECTIVES: To develop a simple and rapid PCR based method for the simultaneous detection of five beta2 AR alleles. METHOD: DNA was extracted from whole blood using standard alkali lysis method. Primers specific at the 3' end for the polymorphic sites were designed. The nested allele specific PCR was optimized for reproducibility and specificity. Parameters investigated included concentrations of MgCl2, Taq polymerase, primers and annealing temperature, to produce specific bands of interest. DNA samples were selected at random and submitted for direct PCR sequencing. RESULT: The first PCR produced a fragment of size 710 bp, which was used as template for the subsequent duplex and triplex PCR to detect the mutation sites of the five alleles. The method was found reproducible and specific when used to genotype patients with bronchial asthma. The sequencing results confirmed the specificity of the PCR method. CONCLUSION: The simple and rapid method for the simultaneous detection of the five beta2 AR alleles is suitable for the study of beta2 polymorphism and its clinical consequences.

Effect of fluoxetine on maximal electroshock seizures in mice: acute vs chronic administration.

There are no definite reports regarding the effects of chronic fluoxetine on animal models of epilepsy. Since chronically administered fluoxetine, in comparison to acutely administered fluoxetine has different effects on CNS, the present study was undertaken to investigate the effect of acute and chronic fluoxetine pretreatment, on a median anticonvulsant dose (ED50) of phenytoin in male ICR albino mice. Additionally, the effects of fluoxetine pretreatment on median convulsive current (CC50) in the presence and absence of phenytoin were investigated and results were compared. The maximal electroshock seizure (MES) test was used to estimate the ED50of phenytoin. The electroshock threshold test was used to estimate CC50. ED50and CC50values were calculated by probit analysis. The effects of the chronic and acute fluoxetine groups on the ED50of phenytoin were significantly different (P<0.05), and on CC50this difference was not statistically significant. Chronic fluoxetine insignificantly increased the ED50of phenytoin and decreased the CC50while acute fluoxetine decreased the ED50of phenytoin and increased the CC50. Our results indicate that chronic fluoxetine does not have an antiepileptic property and it may have dubious proconvulsant properties, contrary to acute fluoxetine.

Laryngeal paralysis in organophosphorous poisoning.

Organophosphorous poisoning causing isolated laryngeal paralysis has only been rarely reported before. We describe a case of difficult extubation in a patient with organophosphorous poisoning, the cause of which was found to be bilateral vocal fold palsy. This is a type of intermediate paralysis that recovers with time. Such a condition should be thought of as a cause of dyspnoea or difficult extubation in patients with organophosphorous poisoning.

Blood pressure regulation by the kallikrein-kinin system.

1. The kallikrein-kinin system has a significant role in regulating arterial blood pressure. 2. Reduced formation of the kinin compontents may cause hypertensive diseases. This is because of the fact that this system is responsible for vasodilatation, reduction in total peripheral resistance, natriuresis, diuresis, increasing renal blood flow and releasing various vasodilator agents. 3. Reduced kinin-kallikrein generation in hypertensive subjects may also be associated with genetic and environmental defects. 4. The kallikrein-kinin system when administered to hypertensive patients can lower their raised blood pressure to normotensive levels. 5. The mode of action of angiotensin-converting enzyme inhibitors principally may be dependent on the kinin system protection.

Suppression of hypotensive responses of captopril and enalapril by the kallikrein inhibitor aprotinin in spontaneously hypertensive rats.

The present investigation evaluated the effects of aprotinin, an inhibitor of kallikrein, on blood pressure responses, heart rate, and duration of hypotension induced by acute administration of captopril and enalapril (angiotensin-converting enzyme inhibitors) in anaesthetized spontaneously hypertensive rats. Captopril (20 mg/kg) and enalapril (20 mg/kg) administered intravenously caused a significant (p < 0.001) fall in systolic and diastolic blood pressures in the absence of aprotinin. In contrast, captopril (20 mg/kg) and enalapril (20 mg/kg) failed (p > 0.05) to cause a fall in systolic and diastolic blood pressures in the presence of aprotinin (2 mg/kg). Captopril and enalapril were able to significantly reduce the heart rate (p < 0.05 and p < 0.001) in the presence as well as in the absence of aprotinin. The duration of hypotension produced by captopril and enalapril was abolished significantly (p < 0.001) in the presence of aprotinin. These findings may suggest that captopril and enalapril caused hypotension via the kallikrein pathway, since the kallikrein inhibitor aprotinin can antagonize the hypotensive responses of these agents. Thus, kallikrein may be an independent mediator in the regulation of blood pressure.

How good are doctors as drug prescribers?

The training of doctors in therapeutics has created interesting discussions internationally. A survey of senior hospital pharmacists currently practising throughout West Malaysia was embarked on during a recent postgraduate seminar. About sixty per cent said prescribing errors were common amongst doctors. Sixteen per cent of the prescribing errors were potentially serious. Most of the time errors were due to carelessness, lack of knowledge on drug action or a combination of both. Nearly 35% of prescribing errors were not acknowledged by doctors. Most doctors did not give reasons for not acknowledging pharmacists' intervention. About half (46.5%) of the respondents thought that doctors were not adequately trained in the use of drugs.

Congenital limb reduction defects: report of two cases.

We describe two Malay male term neonates with congenital limb reduction defects. The first neonate had hypodactyly of limbs associated with micrognathia, microstomia, glossopalatine ankylosis and congenital mitral stenosis. He developed gram-negative septicaemia and died on day 14 of life. The second neonate had tetraperomelia without any other associated congenital abnormality. He developed staphylococcal skin infection which was treated conservatively. Very few cases of congenital limb reduction defects have been reported in the Asian population and we are not aware of any other reports describing Malay infants with the congenital abnormalities described in this report.

Adrenal haemorrhage in a newborn--a case report.

A term female neonate with monolateral adrenal haemorrhage associated with haemorrhagic disease of newborn is described. Diagnosis and follow-up of adrenal haemorrhage was done clinically and sonographically which revealed reduction in the size of adrenal haematoma over a month with no evidence of adrenal insufficiency. She was discharged well and followed up.

A neonate with ectodermal dysplasia ectrodactyly clefting syndrome and ventricular septal defect.

A 37-week gestation male boy was born to a gravida seven para six mother by spontaneous vertex delivery at home. The baby cried at birth. On day 3 of life, he was admitted for respiratory distress. Physical examination revealed ectrodactyly, thin dry skin, anomalous tear duct with cardiomegaly. X-ray revealed absent radii, cardiomegaly and hemivertebra at L1. Echocardiogram revealed perimembranous type of ventricular septal defect. A diagnosis of Ectodermal Dysplasia Ectrodactyly Clefting Syndrome with ventricular septal defect was made. He was managed conservatively in the nursery. However, he expired on day 27 of life following short spell of fever apnoeic episode due to neonatal sepsis.

Acute salicylism due to accidental ingestion of a traditional medicine.

Traditional medicine is practised to some degree in all cultures. Many different types of herbal preparations and "oils" are widely used in Malaysia, too. We report a case of acute salicylism due to accidental ingestion of one brand of such oils. Compulsory labelling of traditional drugs with their chemical ingredients is suggested for proper and timely management of such cases.

Holoprosencephaly in neonates.

A single nostril associated with alobar holoprosencephaly is a rare congenital lesion. This paper reports two female term neonates with holoprosencephaly. The first neonate asphyxiated at birth had a single nostril, hypotelorism, posterior cleft palate, inferonasal coloboma of the iris and disc and persistent tunica vasculosa lentis. The other neonate had cleft lip and palate and recurrent convulsions. Both neonates had gross motor and developmental delay. Cranial sonography and CT scan showed features consistent with alobar holoprosencephaly. Karyotyping for the first neonate and her family members was normal. Both of them were treated conservatively and supervised.