Impacts of counseling on knowledge, attitude and practice of medication use during pregnancy

Background

Counseling has a significant role in improving knowledge, attitude and practice outcomes of pregnant women towards medication use. Proper counseling thus could be beneficial to prevent any medication related misadventure during pregnancy. The present study was aimed to assess the knowledge, attitude and practice (KAP) of pregnant women towards their medications, to provide counseling regarding their understanding of medication use during pregnancy and evaluate the impacts of such counseling.

Methods

Pre- post interventional (counseling) study was conducted at Manipal Teaching Hospital, Nepal among pregnant women who presented with complication and were prescribed at least one medication. A total of 275 pregnant women were included in the study. A structured questionnaire was used to assess the knowledge, attitude and practice of pregnant women before and after counseling. The impacts of counseling were then evaluated using suitable statistical methods.

Results

Of the total participants 229 completed the post counseling survey. Majority of the participants were in the age group 20-24 (43.2%), primigravida (59.4%) and in third trimester (58.6%). Housewives comprised 61.1% of participants and majority had received a University degree (33.2%).

The mean and median scores assessed before counseling showed that there was no significant difference in the KAP scores with respect to age, trimester and gravidity whereas KAP scores with respect to occupation and level of education were statistically significant. There was an increase in mean and median KAP scores after counseling and the impacts of counseling was found to be statistically significant (p = <0.001).

Conclusion

Counseling had a positive impact on knowledge, attitude and practice of pregnant women towards medication and thus it could be considered a suitable method to encourage safe medication during pregnancy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-017-1316-6) contains supplementary material, which is available to authorized users.

Medication utilization pattern for management of pregnancy complications: a study in Western Nepal

Background

Drugs used during pregnancy can adversely affect the health and life of the mother and unborn child. However, the fact that drugs are needed to mitigate complications during pregnancy cannot be avoided. The present study was designed to identify the common complications during pregnancy and assess the medications that have been used to mitigate those complications in an attempt to improve drug prescribing during pregnancy.

Methods

A hospital based cross sectional study was conducted at Manipal Teaching Hospital, Nepal in 275 pregnant women presenting with at least one complication and the drugs prescribed for the management of those complications were analyzed.

Results

Majority of the patients in this study were in the age group 20–24 (44 %) and in the third trimester (53.8 %). Maximum patients complained pain (back, abdominal, lower abdominal, neck, pelvic) as primary complication (24.3 %) which was followed by nausea/vomiting, upper respiratory tract complications, acid reflux disease and others. Of the total prescriptions eighty six (86) did not have any medicines prescribed to the patients except multivitamins and nutritional supplements. The average drugs prescribed per patient was 2.78 in outpatient setting and 5.41 in in-patients. Ranitidine, hyoscine butylbromide, paracetamol were the most frequently prescribed medications. Antimicrobials comprised 12.8 % of total drugs prescribed and 18 % of total drugs were fixed dose combinations. Two hundred and thirty four (234) prescriptions out of 275 were prescribed by brand names. Most of the prescribed drugs were from FDA pregnancy category B and C.

Conclusion

The present finding showed that pregnant patients were prescribed medications almost only when necessary and those considered safe during pregnancy were chosen to a large extent. However, few teratogenic drugs (2.49 % of total drugs prescribed) were also found to be prescribed which might need further assessments.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-1068-8) contains supplementary material, which is available to authorized users.

Formulation, and physical, in vitro and ex vivo evaluation of transdermal ibuprofen hydrogels containing turpentine oil as penetration enhancer

The aim of the present study was to investigate the transdermal permeation enhancing capability of turpentine oil for ibuprofen from hydrogels. Ibuprofen 1% w/v hydrogels were developed with carboxypolymethylene with and without turpentine oil. Turpentine oil was incorporated in increasing concentrations, i.e. 0.5, 1, 1.5, 2, 2.5 and 3% of the total gel formulation, and its permeation enhancing effect was examined. Gels were examined physically for pH, viscosity, spreadability, extrudability, smoothness and appearance. To study the in vitro and ex vivo permeation potential of formulated gels, permeation studies were performed with a Franz diffusion cell using cellulose membrane and excised rabbit abdominal skin. Ibuprofen hydrogel with 3% turpentine oil showed a maximum flux of 10.87 mg/cm2/h across artificial skin and 17.26 mg/cm2/h across rabbit abdominal skin.

Formulation and evaluation of controlled release matrices of ketoprofen and influence of different co-excipients on the release mechanism

The present work reports the study of different controlled release formulations of ketoprofen, which is a non-steroidal anti-inflammatory drug (NSAID) and like other NSAIDs requires large and frequent daily doses, resulting in severe side effects and non-compliance. To avoid these problems, controlled release matrices were developed using different grades of ethylcellulose polymer with a drug-polymer ratio of 10:3 by the direct compression method. The effect on drug release of partial replacement of lactose by different co-excipients, HPMC K100 M, starch and CMC, was also studied. The tablets were tested for their drug content, weight variation, friability, hardness, thickness and diameter, all these physical properties being within the USP range. The release profile of all formulations containing polymer and co-excipients was compared with a formulation developed without polymer and co-excipients. After a 24-hour release study, it was concluded that formulations containing different grades of ethylcellulose polymer showed prolonged release for 6-18 hours, but the formulation containing the polymer Ethocel standard FP 7 Premium without co-excipient showed controlled release for 24 hours. DSC and FT-IR studies were performed to investigate any incompatibility between drug, polymer and co-excipient but no interaction was found. Different kinetic models were used, such as first order equation, zero order equation, Higuachi equation, Hixon Crowel's equation and Korsmeyer-Peppas to study the release mechanism. The formulations containing co-excipients showed an enhanced release rate.

Reducing CSF shunt placement in patients with spinal myelomeningocele

OBJECT

The incidence of hydrocephalus requiring shunts in children with myelomeningocele (MMC) is reported to be very high. Shunt-related complications are a significant cause of morbidity and mortality in this population. In order to minimize shunt placements, we used very rigid clinical selection criteria and followed them in all patients who had myelomeningocele and enlarged ventricles. The follow-up outcome of this retrospective study is reported.

METHODS

From 2000 to 2007, 23 patients with myelomeningocele and variable degree of hydrocephalus were treated at our institute with primary surgical closure of their myelomeningoceles without a CSF diversion procedure. Patients with severe hydrocephalus who required immediate shunt insertion, and those with no significant associated hydrocephalus were not included in this study. Data regarding the surgical results and complications, postoperative management, and the outcome at follow-up were obtained from their hospital records.

RESULTS

Initially increased size of the ventricular system was found to have decreased or stabilized in 17 (81%) patients postoperatively. However, ventriculomegaly continued to progress further in 4 (19%) out of 21 patients. Of 11 patients who presented with enlarged head, eight (73%) patients showed reduction or stabilization in their head circumference. Three (27%) children continued to have progressive head enlargement in the postoperative period and required shunt placement. Signs of raised intracranial pressure observed in six patients on admission, improved in two (33%) and persisted or worsened in four (67%) patients who eventually improved after the insertion of a shunt. Eight (35%) patients experienced wound-related complications following closure of the MMC, including CSF leak in four, wound infection in three, wound breakdown in three, and pseudomeningocele in two patients. Shunt placement was required in the postoperative period in 13 (56.5%) patients to treat raised intracranial pressure in 11 and CSF leak from the wound in two patients.

CONCLUSIONS

Our experience suggests that the placement of shunts can be reduced by adopting a policy with strict clinical and radiographic criteria. Shunt insertion should be reserved for only those patients who have severe hydrocephalus with clinical features of elevated intracranial pressure. Mild to moderate ventricular dilatation, persistent ventriculomagaly, and some increase in ventricular size after myelomeningocele repair can be treated successfully without a shunt.

Cauda equina paraganglioma presenting with intracranial hypertension: case report and review of the literature

An unusual case of intradural paragangliomas in the cauda equina region in a 29-year-old male is presented. The patient presented with signs and symptoms of raised intracranial pressure. The symptoms resolved after tumor resection.

Role of primary afferent nerves in allodynia caused by diabetic neuropathy in rats

Both myelinated and unmyelinated afferents are implicated in transmitting diabetic neuropathic pain. Although unmyelinated afferents are generally considered to play a significant role in diabetic neuropathic pain, pathological changes in diabetic neuropathy occur mostly in myelinated A-fibers. In the present study, we first examined the role of capsaicin-sensitive C-fibers in the development of allodynia induced by diabetic neuropathy. We then studied the functional changes of afferent nerves pertinent to diabetic neuropathic pain. Diabetes was induced in rats by i.p. streptozotocin. To deplete capsaicin-sensitive C-fibers, rats were treated with i.p. resiniferatoxin (300 microg/kg). Mechanical and thermal sensitivities were measured using von Frey filaments and a radiant heat stimulus. Single-unit activity of afferents was recorded from the tibial nerve. Tactile allodynia, but not thermal hyperalgesia, developed in diabetic rats. Resiniferatoxin treatment did not alter significantly the degree and time course of allodynia. Post-treatment with resiniferatoxin also failed to attenuate allodynia in diabetic rats. The electrophysiological recordings revealed ectopic discharges and a higher spontaneous activity mainly in Adelta- and Abeta-fiber afferents in diabetic rats regardless of resiniferatoxin treatment. Furthermore, these afferent fibers had a lower threshold for activation and augmented responses to mechanical stimuli. Thus, our study suggests that capsaicin-sensitive C-fiber afferents are not required in the development of allodynia in this rat model of diabetes. Our electrophysiological data provide substantial new evidence that the abnormal sensory input from Adelta- and Abeta-fiber afferents may play an important role in diabetic neuropathic pain.

Antiallodynic effect of intrathecal neostigmine is mediated by spinal nitric oxide in a rat model of diabetic neuropathic pain

BACKGROUND

Intrathecal administration of acetylcholinesterase inhibitors produces antinociception in both animals and humans, but their effect on diabetic neuropathic pain has not been studied. In the current study, we determined the antiallodynic effect of intrathecal injection of an acetylcholinesterase inhibitor, neostigmine, in a rat model of diabetic neuropathic pain. In addition, since acetylcholine can increase release of nitric oxide in the spinal cord, we studied the role of spinal endogenous nitric oxide in the action of intrathecal neostigmine in diabetic neuropathic pain.

METHODS

Rats were rendered diabetic with an intraperitoneal 50-mg/kg injection of streptozotocin. Intrathecal catheters were inserted, with tips in the lumbar intrathecal space. Mechanical allodynia was determined by application of von Frey filaments to the hind paw. We first determined the dose-dependent effect of intrathecal neostigmine on allodynia. The role of spinal nitric oxide in the action of intrathecal neostigmine was then examined through intrathecal treatments with a neuronal nitric oxide synthase inhibitor (TRIM), a nitric oxide scavenger (PTIO), L-arginine, or D-arginine.

RESULTS

The diabetic rats developed a sustained tactile allodynia within 4 weeks after streptozotocin injection. Intrathecal injection of 0.1-0.5 microg neostigmine dose-dependently increased the withdrawal threshold in response to application of von Frey filaments. Intrathecal pretreatment with 30 microg TRIM or 30 microg PTIO abolished the antiallodynic effect of intrathecal neostigmine. Furthermore, the inhibitory effect of TRIM on the action of intrathecal neostigmine was reversed by intrathecal injection of 100 microg L-arginine but not D-arginine.

CONCLUSIONS

Intrathecal neostigmine produces a profound analgesic effect in a rat model of diabetic neuropathic pain. Spinal endogenous nitric oxide contributes to the analgesic action of intrathecal neostigmine in this rat model of diabetic neuropathic pain.

2-chloro-N(6)-cyclopentyladenosine-elicited attenuation of evoked glutamate release is not sufficient to give complete protection against pilocarpine-induced seizures in rats

The effects of 2-chloro-N(6)-cyclopentyladenosine (CCPA) perfused intrahippocampally (1 microM) and injected intraperitoneally (0.5 mg/kg) were investigated in focally-evoked pilocarpine-induced (10 mM) seizures in freely moving rats. While the intrahippocampal perfusion of this highly selective adenosine A(1) receptor agonist gave complete protection against pilocarpine-induced seizures, systemic administration only partially protected the animals, as evaluated by concomitant behavioural and electrocorticographical (ECoG) observations and monitoring of the neurotransmitter alterations. However, pilocarpine-evoked elevation of hippocampal glutamate overflow was significantly attenuated by CCPA irrespective of the mode of administration. Acute pretreatment with systemic 8-cyclopentyl-1,3-dipropylxanthine, a selective A(1) antagonist, reversed both the partial protective effect and the attenuating effect on the extracellular glutamate elicited by systemic CCPA administration. Intrahippocampal CCPA markedly reduced basal hippocampal dopamine efflux but not GABA or glutamate and considerably attenuated the pilocarpine-evoked elevation in dopamine levels. Systemic CCPA appeared to have little influence on the overall pattern of dopamine elevation. The findings give evidence that CCPA-elicited abatement of the evoked glutamate release alone, cannot fully account for its anticonvulsant effect and may suggest that the effects mediated by adenosine on postsynaptic adenosine receptors could be more crucial for its anticonvulsant effect.

Pathology of the appendix

An audit of 3374 appendectomy specimens in 2578 Saudi and 796 non-Saudi nationals revealed a diagnosis rate of 74.7% of inflamed appendix, a normal appendix range of 7.8% to 22.5% with the higher rate of normal appendix found among females. The finding of high incidence of schistosomal appendicitis among Egyptian males is not surprising given the high incidence of schistosomiasis among Egyptians in general. The alternate diagnoses, which include such conditions as neoplasm, mucocele, other inflammatory conditions such as periappendicitis, and parasitic infestations, are not different from findings in the reported literature.

In vivo study of the effect of valpromide and valnoctamide in the pilocarpine rat model of focal epilepsy

PURPOSE

We evaluated the effectiveness of the commonly used antiepileptic drug sodium valproate (400 mg/kg) and two of its amide derivatives, valpromide and valnoctamide (both 100 mg/kg), in an in vivo rat model of focal epilepsy. Our main interest was to get insight into possible changes in extracellular amino acid neurotransmitter levels following administration of the drugs, both in control and in epileptic conditions.

METHODS

Seizures were evoked in freely moving rats by intrahippocampal administration of pilocarpine via a microdialysis probe (10 mM for 40 min at 2 microl/min). Microdialysis was also used as in vivo sampling technique and alterations in extracellular hippocampal glutamate and GABA levels were monitored. Electrophysiological evidence for the presence or absence of seizures was simultaneously recorded with electrocorticography.

RESULTS

The focally evoked pilocarpine-induced seizures were completely prevented by acute intraperitoneal pretreatment with each of the three drugs in the respective doses. Effective protection was reflected in the electrocorticographic recordings and in the lack of sustained elevations of the extracellular glutamate levels after pilocarpine perfusion. Little effects were seen on the basal extracellular amino acid levels after systemic administration of each of the compounds, nor after the intrahippocampal administration of sodium valproate.

CONCLUSIONS

Valnoctamide and valpromide (100 mg/kg) proved to be at least as effective as their parent compound sodium valproate (400 mg/kg) against pilocarpine-induced seizures. All three compounds however failed to induce significant initial alterations in extracellular hippocampal GABA release. This questions the enhancement of GABA-mediated inhibition as being one of their mechanisms of action.

Flumazenil prevents diazepam-elicited anticonvulsant action and concomitant attenuation of glutamate overflow

Systemic administration of diazepam (5 mg/kg, i.p.) produced a prompt anticonvulsant effect in pilocarpine-induced seizures in freely moving rats. The anticonvulsant effect was associated with significant attenuation of pilocarpine-evoked increases in extracellular hippocampal glutamate levels to below the baseline levels. The purpose of the present microdialysis study, therefore, was to investigate if the effect of diazepam on glutamate release was mediated at the level of the benzodiazepine gamma-aminobutyric acid(A) (GABA(A)) receptor complex to preclude any non-GABAergic mechanisms. Systemic administration of the specific benzodiazepine-receptor antagonist flumazenil (10 mg/kg, i.p. )-elicited complete reversal of diazepam-evoked anticonvulsant action and concomitant attenuation of extracellular glutamate efflux below the baseline levels. This provides evidence that under the given experimental conditions, diazepam-evoked alterations in glutamate overflow associated with the anticonvulsant action were indeed mediated at the level of benzodiazepine-GABA(A) receptor complex, possibly involving the modulation of both pre- and post-synaptic sites of the receptor complex.

Anticonvulsant effect and neurotransmitter modulation of focal and systemic 2-chloroadenosine against the development of pilocarpine-induced seizures

The present microdialysis study was aimed at evaluating the anticonvulsant effect of the adenosine A(1) receptor agonist 2-chloroadenosine (2-CADO) against pilocarpine-induced seizures in rats. The hippocampal neurotransmitter modulation on the action of 2-CADO and its possible activation of hippocampal adenosine A(2a) receptors was also assessed. Intrahippocampal perfusion of 2-CADO (100 microM) produced a sustained attenuation of baseline dopamine levels, while eliciting a delayed augmentation of both glutamate and GABA efflux. When co-perfused with pilocarpine (10 mM) or injected systemically (7.5 mg/kg), 2-CADO prevented the development of seizures as well as pilocarpine-evoked augmentation of the glutamate and dopamine levels. However, the delayed increase in glutamate overflow with intrahippocampal 2-CADO was still observed. Intraperitoneal injection of selective adenosine A(2a) receptor antagonist SCH 58261 reversed the 2-CADO-elicited attenuation of pilocarpine-induced increment in dopamine efflux and completely abolished the delayed augmentation of glutamate levels, irrespective of perfusion with pilocarpine. Intraperitoneal injection of 5 mg/kg 2-CADO mostly prevented the elevation of pilocarpine-induced glutamate efflux but could not confer adequate protection. We conclude that 2-CADO can prevent pilocarpine-induced seizures by both intrahippocampal perfusion and systemic administration. The attenuation of pilocarpine-induced dopamine efflux and the late elevations of glutamate are likely to be mediated by hippocampal A(2a) receptors. Inhibition of presynaptic glutamate release does not appear to be sufficient for the anticonvulsant action. Postsynaptic events could play a more important role.

Controlled release coprecipitates of ibuprofen and a carbomer: preparation, characterization and in vitro release studies

Extended release coprecipitates of ibuprofen (IBF) and carbopol 934P-NF, in the form of micro-matrices, were prepared using two different methods. The drug-carbomer interactions in the solid state were investigated employing Infra Red (IR) Spectroscopy, Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM). Dissolution experiments were performed using simulated gastric fluid (SGF- pH 1.2), distilled water, and pH 7.2 phosphate buffer solution as dissolution media. No well- defined chemical interaction between the ingredients was found. The methods of preparation of the coprecipitates are simple, practical, minimize the use of toxic organic solvents, and can be used in the production of controlled release tablets.

Effects of diazepam on extracellular brain neurotransmitters in pilocarpine-induced seizures in rats

The present study was undertaken to gain insights into the mechanism of action of diazepam in focally-evoked pilocarpine-induced seizures by concomitantly assessing the changes produced in the extracellular levels of glutamate, GABA (gamma-aminobutyric acid) and dopamine. In vivo microdialysis, coupled to continuous monitoring of electrocorticographic (ECoG) recordings, was performed in freely moving rats. Intrahippocampal perfusion with 10 mM pilocarpine (40 min, 2 microl/min) produced limbic seizures. A single dose of intraperitoneal diazepam (5 mg/kg) was administered 2 h after pilocarpine perfusion was started. Dialysates were sampled both from hippocampus and cerebellum and analysed by microbore liquid chromatography. Diazepam produced instant inhibition of behavioural and ECoG seizure activity. Pilocarpine-induced increases in the extracellular levels of glutamate and dopamine in hippocampus were promptly reduced by diazepam. No concurrent alterations in pilocarpine-induced increases in the extracellular levels of GABA in either hippocampus or cerebellum were seen. Pilocarpine enhanced cerebellar glutamate levels only transiently and levels returned to baseline before diazepam administration. No further changes in cerebellar glutamate levels were observed with diazepam. Our findings suggest that the anti-convulsant action of diazepam against pilocarpine-induced seizures is associated with a prompt attenuation of extracellular hippocampal glutamate overflow without concurrent alteration of pilocarpine-induced increases in endogenous GABA levels. Diazepam also significantly decreased pilocarpine-induced increases in extracellular dopamine levels within the hippocampus. No immediate alterations of the basal levels of the neurotransmitters monitored were observed with diazepam.

Studies on drug release kinetics from ibuprofen-carbomer hydrophilic matrix tablets: influence of co-excipients on release rate of the drug

Controlled-release (CR) matrix tablets of ibuprofen (IBF) and Carbopol(R) 934P, and blended mixture of Carbopol(R) 934P and 971P resins, at different drug to polymers ratios, were prepared by the direct compression method. The investigation focuses on the influence of the proportion of the matrix material, and several co-excipients (lactose, microcrystalline cellulose (MCC), and starch) on the mechanism and release rate of the drug from the tablets. In vitro drug release in pH 7.2 phosphate buffer solution appears to occur both by diffusion and a swelling-controlled mechanism, exhibiting either anomalous or Case II type transport. The release process could be described by plotting the fraction released versus time and fitting data to the simple exponential model: Mt/Minfinity=ktn. The release kinetics were modified when the blended mixtures of Carbopol(R) 934P and 971P resins were used as the matrix materials. In general, all of the co-excipients, used in this study, enhanced the release rate of IBF. However, lactose demonstrated slower and more linear release behavior as compared to microcrystalline cellulose or starch. The dissolution T50 and T90 values for the three co-excipients were in the order of lactose>microcrystalline cellulose>starch.

Formulation and in vitro evaluation of ibuprofen-Carbopol 974P-NF controlled release matrix tablets. III: Influence of co-excipients on release rate of the drug

In order to assess the potential of carbopol 974P-NF as matrix material in hydrophilic matrix tablets containing a slightly water-soluble drug, ibuprofen (IBF), controlled release matrix tablets of ibuprofen and carbopol 974P-NF, at different drug to polymer ratios, were prepared by the direct compression method. The influence of the concentration of the matrix material (carbopol 974P) and several co-excipients (lactose, microcrystalline cellulose, and starch) on the release rate of the drug was investigated. An in vitro dissolution test in pH 7.2 phosphate buffer solution showed that drug release from all the formulations containing carbopol 974P was considerably prolonged in concentration-dependent manners. Increasing the amount of carbopol 974P in tablets resulted in a reduction in the drug release rate and a linearization of the drug release curve. When the influence of the co-excipients on the release of the drug was examined, all of the co-excipients used in this study enhanced the release rate of IBF. However, lactose demonstrated slower and more linear release behavior as compared in microcrystalline cellulose or starch. The dissolution T50 and T90 values for the three co-excipients were in the order of lactose > microcrystalline cellulose > starch.

Preparation, characterization, and evaluation of physicochemical properties of different crystalline forms of ibuprofen

Different crystal forms of ibuprofen (IBF) were prepared using methods such as cooling hot solution of the drug and precipitation of crystals from the drug solution. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), melting point, x-ray powder diffractometry, infrared absorption spectroscopy (IR), and in vitro dissolution rate and stability studies were conducted to investigate various characteristics of different crystalline forms of the drug. Methods of preparation and nature of the solvents used in this study were found to have greater roles in changing the physicochemical properties of IBF.

Preparation, characterization, and dissolution studies of ibuprofen solid dispersions using polyethylene glycol (PEG), talc, and PEG-talc as dispersion carriers

Solid dispersions of ibuprofen (IBF) were prepared by solvent evaporation method using polyethylene glycol 10000 (PEG), talc, and PEG-talc as dispersion carriers. The drug-carrier(s) interactions in the solid state were investigated using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and x-ray diffraction analysis. Interactions in the solution were studied by performing dissolution experiments. No important and well-defined chemical interaction was found between the ingredients. The increase in the IBF dissolution rate from the solid dispersions with the carriers used in this study could be attributed to several factors such as improved wettability, local solubilization, and drug particle size reduction.

Effectiveness of vigabatrin against focally evoked pilocarpine-induced seizures and concomitant changes in extracellular hippocampal and cerebellar glutamate, gamma-aminobutyric acid and dopamine levels, a microdialysis-electrocorticography study in freely moving rats

Limbic seizures were evoked in freely moving rats by intrahippocampal administration of the muscarinic agonist pilocarpine via the microdialysis probe (10 mM for 40 min at 2 microl/min). This study monitored changes in extracellular hippocampal gamma-aminobutyric acid (GABA), glutamate and dopamine levels after systemic (30 mg/kg/day) or local (intrahippocampal or intranigral, 5 mM or 600 microM for 180 min at 2 microl/min) vigabatrin administration, and evaluated the effectiveness of this antiepileptic drug against pilocarpine-induced seizure activity. Extracellular GABA and glutamate overflow in the ipsilateral cerebellum was studied simultaneously. Microdialysis was used as an in vivo sampling technique and as a drug-delivery tool. Electrophysiological evidence for the presence or absence of seizures was recorded with electrocorticography. The observed alterations in extracellular hippocampal amino acid levels support the hypothesis that muscarinic receptor stimulation by the intrahippocampal administration of 10 mM pilocarpine is responsible for the seizure onset, and that the amino acids maintain the sustained seizure activity. The focally evoked pilocarpine-induced seizures were completely prevented by intraperitoneal vigabatrin premedication for 7 days or by a single intraperitoneal injection. Effective protection was reflected in a lack of sustained elevations of hippocampal glutamate levels. Rats receiving vigabatrin intrahippocampally or intranigrally still developed seizures, although there appeared to be a partial protective effect. During the intrahippocampal perfusion with 5 mM vigabatrin, extracellular hippocampal GABA levels increased, whereas the extracellular glutamate and dopamine overflow decreased. The lack of a complete neuroprotection after local vigabatrin treatment is discussed.

NMDA receptor-mediated pilocarpine-induced seizures: characterization in freely moving rats by microdialysis

1. Pilocarpine administration has been used as an animal model for temporal lobe epilepsy since it produces several morphological and synaptic features in common with human complex partial seizures. Little is known about changes in extracellular neurotransmitter concentrations during the seizures provoked by pilocarpine, a non-selective muscarinic agonist. 2. Focally evoked pilocarpine-induced seizures in freely moving rats were provoked by intrahippocampal pilocarpine (10 mM for 40 min at a flow rate of 2 microl min(-1)) administration via a microdialysis probe. Concomitant changes in extracellular hippocampal glutamate, gamma-aminobutyric acid (GABA) and dopamine levels were monitored and simultaneous electrocorticography was performed. The animal model was characterized by intrahippocampal perfusion with the muscarinic receptor antagonist atropine (20 mM), the sodium channel blocker tetrodotoxin (1 microM) and the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 (dizocilpine maleate, 100 microM). The effectiveness of locally (600 microM) or systemically (10 mg kg(-1) day(-1)) applied lamotrigine against the pilocarpine-induced convulsions was evaluated. 3. Pilocarpine initially decreased extracellular hippocampal glutamate and GABA levels. During the subsequent pilocarpine-induced limbic convulsions extracellular glutamate, GABA and dopamine concentrations in hippocampus were significantly increased. Atropine blocked all changes in extracellular transmitter levels during and after co-administration of pilocarpine. All pilocarpine-induced increases were completely prevented by simultaneous tetrodotoxin perfusion. Intrahippocampal administration of MK-801 and lamotrigine resulted in an elevation of hippocampal dopamine levels and protected the rats from the pilocarpine-induced seizures. Pilocarpine-induced convulsions developed in the rats which received lamotrigine perorally. 4. Pilocarpine-induced seizures are initiated via muscarinic receptors and further mediated via NMDA receptors. Sustained increases in extracellular glutamate levels after pilocarpine perfusion are related to the limbic seizures. These are arguments in favour of earlier described NMDA receptor-mediated excitotoxicity. Hippocampal dopamine release may be functionally important in epileptogenesis and may participate in the anticonvulsant effects of MK-801 and lamotrigine. The pilocarpine-stimulated hippocampal GABA, glutamate and dopamine levels reflect neuronal vesicular release.

Thyroid malignancy in multinodular goitre and solitary nodule

This is a retrospective study of 361 thyroid specimens during a 6 1/2-year period with the objective of investigating the prevalence and pattern of thyroid malignancy associated with multinodular goitre (MNG) and solitary nodule (SN). Fourteen of 172 MNG (8%) and 16 of 105 SN (15.2%) were associated with malignancy, a statistically insignificant difference (P = 0.06). Unlike in males, malignancy was significantly commoner in females with SN than those with MNG (P = 0.03) and generally occurred at a significantly older age (P < 0.05). On analysing thyroid carcinoma and lymphoma separately, patients with SN had a higher incidence of carcinoma compared with those with MNG (P = 0.01). It is concluded that surgical intervention may be the appropriate method of treating male patients presenting with MNG. However, in females, conservative management of MNG should be adopted unless surgery is indicated depending on clinical judgement and, if feasible, the result of fine needle aspiration biopsy.

Schistosomal appendicitis

This is a retrospective study involving 4708 consecutive appendix specimens removed over a period of 6.5 years for a clinical diagnosis of acute appendicitis, 64 (1.3%) of which showed histological evidence of schistosomiasis. Thirty-four schistosomal appendicitis (SA) cases were compared with 68 non-schistosomal appendicitis (NSA) cases admitted during the same period. SA patients were older in age, usually of male sex, mostly Egyptians and tended to have a higher hemoglobin and a lower leukocyte count (P<0.05). Other features were not significantly different. It is concluded that, despite these differences, there are no reliable clinical or laboratory features by which SA can be predicted preoperatively. The majority of the studied patients were either discharged before the results of the histopathology study were ready and were lost to follow-up or the reports were overlooked. Therefore, we recommend that for all post-appendectomy patients living in or coming from endemic areas of schistosomiasis, the results of the histopathology study should be processed as early as possible and before the patient can be discharged so that the treatment can be commenced. Moreover, establishing a system by which infected patients could be traced and hence treated is highly recommended.

An unusual orbito-cranial foreign body

The rarity of orbito-cranial gun shot injury in both war and civilian practice has been reported. In a large series of 351 missile head injuries in the Vietnam war, orbital penetration was noted in 0.6% cases only. Review of literature shows that orbital injury was ipsilateral to the cerebral injury in most reported cases. We have previously reported a rare case of left parieto-occipital lobe injury due to gun shot wound of the contralateral (right) orbit. The case reported here sustained a bullet injury to the left frontal bone but the missile was located below the contralateral (right) optic canal. The rarity of the case prompted this report.

The Adsorption of Alkylchlorosilanes on Quartz Crystal Surfaces

The piezogravimetric method has been used to study the adsorption of dimethyl and trimethylchlorosilanes on quartz crystal surfaces by varying the modes of treatment. The nature of the resulting low-energy surfaces has been discussed in the light of the extent of adsorption of n-hexane and water, calculated at different relative pressures, from their isotherms. The results obtained permit the conclusion that after the adsorption of silanes at 240 °C, the modified surface may be described as close-packed methyl surface, impenetrable to n-alkane and water vapour.