Comparable fMRI activity with differential behavioural performance on mental rotation and overt verbal fluency tasks in healthy men and women

To explicate the neural correlates of sex differences in visuospatial and verbal fluency tasks, we examined behavioural performance and blood-oxygenation-level-dependent (BOLD) regional brain activity, using functional magnetic resonance imaging, during a three-dimensional (3D) mental rotation task and a compressed sequence overt verbal fluency task in a group of healthy men (n=9) and women (n=10; tested during the low-oestrogen phase of the menstrual cycle). Men outperformed women on the mental rotation task, and women outperformed men on the verbal fluency task. For the mental rotation task, men and women activated areas in the right superior parietal lobe and the bilateral middle occipital gyrus in association with the rotation condition. In addition, men activated the left middle temporal gyrus and the right angular gyrus. For verbal fluency, men activated areas in the bilateral superior frontal gyrus, right cingulate gyrus, left precentral gyrus, left medial frontal gyrus, left inferior frontal gyrus, thalamus, left parahippocampal gyrus and bilateral lingual gyrus, and women activated areas in the bilateral inferior frontal gyrus and left caudate. Despite observing task related activation in the hypothesised areas in men and women, no areas significantly differentiated the two sexes. Our results demonstrate comparable brain activation in men and women in association with mental rotation and verbal fluency function with differential performance, and provide support for sex differences in brain–behaviour relationships.     

Prevalence of nonfermenters in clinical specimens

One hundred and thirty three non fermenting gram negative bacilli isolated out of 625 different clinical specimens were identified and characterised. Samples were exudate from chronic suppractive otits media (341), diabetic foot (117) wound (116) and blood (51). Of these isolates Pseudomonas aeruginosa 105(78.94%) predominated followed by Acinetobacter sp 8 [6.1%], Pseudomonas putrifaciens 6(4.5%), Flavobacterium sp 6(4.5%), Xanthomonas maltophilia 5(3.75%), Alkaligenes sp 3 (2.25). 31 (23.30%) were resistant to commonly used antibiotics. Amikacin 85 (63.90%) was found to be more effective than fluoroquinolones (27.8-48.12%).     

Anticonvulsive activity of Butea monosperma flowers in laboratory animals

The bioassay-guided fractionation of dried flowers of Butea monosperma (BM) was carried out to isolate the active principle responsible for its anticonvulsant activity. The petroleum ether extract was fractionated by column chromatography using solvents of varying polarity such as n-hexane, n-hexane:ethyl acetate, ethyl acetate, and methanol. The anticonvulsive principle of B. monosperma was found to be a triterpene (TBM) present in the n-hexane:ethyl acetate (1:1) fraction of the petroleum ether extract. TBM exhibited anticonvulsant activity against seizures induced by maximum electroshock (MES) and its PD(50) was found to be 34.2+/-18.1 mg/kg. TBM also inhibited seizures induced by pentylenetetrazol (PTZ), electrical kindling, and the combination of lithium sulfate and pilocarpine nitrate (Li-Pilo). However, TBM was not effective against seizures induced by strychnine and picrotoxin. TBM exhibited depressant effect on the central nervous system. After repeated use for 7 days, the PD(50) (MES) of TBM increased to 51.5+/-12.1 mg/kg. Similarly, after repeated use of TBM, the duration of sleep induced by pentobarbital was not reduced significantly. Further studies are required to investigate its usefulness in the treatment of epilepsy.     

Bradycardia associated with intravenous methadone administered for sedation in a patient with acute respiratory distress syndrome

The use of low tidal volumes with permissive hypercapnia in patients with acute respiratory distress syndrome may require heavy sedation to allow them to tolerate mechanical ventilation. Administration of methadone for sedation is an alternative to using other opioids, given its longer elimination half-life and incomplete cross-tolerance with other mu-receptor-active opioids. Methadone appears to have a molecular structure similar to that of verapamil, a calcium channel blocker, and may exhibit similar cardiac properties as well. A 43-year-old man with acute respiratory distress syndrome experienced bradycardia while receiving a continuous infusion of methadone for sedation and mechanical ventilation management. This case report demonstrates that caution is warranted when high dosages of methadone are administered because of its potential cardiac effects.     

Brain imaging: a key to understanding depression

According to the World Development Report 1993 one third of people with a mental illness suffer from a depressive disorder. There is a need for early diagnosis and effective treatment in order to limit the impact on patients' lives. Knowledge gained from brain imaging research may help to improve our understanding and treatment of depression.