Neuropharmacological profile of aqueous extract of Anaphe venata larva (Notondotidae) in rats

Consumption of Anaphe larva had been reported to cause seasonal ataxia and impaired consciousness. Therefore this study examined the neuropharmacological and mechanism(s) of action of aqueous extract of Anaphe venata in rats. Behavioural effects namely rearing, stretching, sniffing and ataxia were determined after the intraperitoneal administration of aqueous extract of Anaphe larva in rats. Animals were divided into groups and graded doses (100, 200 and 400 mg/kg, i.p.) of extract were administered. The control group was administered normal saline (vehicle). The effects of scopolamine (3 mg/kg, i.p.), flumazenil (2 mg/kg, i.p.), naloxone (2.5 mg/kg, i.p.), and thiamine (1 mg/kg, i.p.) on the observed behavioral changes were also examined. The effects of the extract administered intraperitoneally at a dose of 200 mg/kg on the amphetamine-induced stereotypy and locomotion were evaluated. Aqueous anaphe extract induced significant (p< 0.01) stretching and ataxia behavioural effects while it inhibited rearing behaviour when compared with the vehicle-treated group. However, it had no significant effect on sniffing behaviour. Scopolamine reversed all the effects of the extract on rearing, stretching and ataxia. Both Flumazenil and naloxone only reversed the effects of the extract on stretching and ataxia-induced behaviours significantly. However, thiamine potentiated both stretching and ataxia-induced behaviours. The extract inhibited the amphetamine-induced stereotype behaviour and locomotion. In conclusion, these results showed that these anaphe-induced behavioural effects are mediated via cholinergic, GABAergic, opioidergic and dopaminergic receptor systems with strong muscarinic-cholinergic receptors involvement in ataxia-induced behaviour. We therefore suggest that muscranic-cholinergic like drugs may be of benefit in the management of patients that present with clinical condition of seasonal ataxia.     

Preoperative assessment of patients with end stage renal failure

Patients with end stage renal failure (ESRF) present a number of challenges to the anesthesiologist. They may be chronically ill and debilitated and have the potential for multisystem organ dysfunction. Patients with primary renal disease are likely younger and have good cardiopulmonary reserve. Older patients with renal failure secondary to diabetes mellitus or hypertension may suffer the ravages of diffuse atherosclerosis and heart disease. To safely manage these patients we need to understand the benefits and limitations of dialysis, problems related with primary disease, pathophysiological effects of ESRF, and the altered pharmacology of commonly used anesthetic agents and perioperative medications in ESRF. Problems encountered by anesthesiologist in ESRF patients include hypertension, ischemic heart disease, congestive heart failure, anemia, metabolic acidosis, hyperkaliemia, hyponatremia and circulatory collapse. All surgical procedure in patients with ESRF carries significant risk of peri- and postoperative complications (mostly cardiovascular) and even fatal outcome.     

Ocular melanoma presenting as a case of panophthalmitis in a 78-year-old Nigerian woman (masquerade syndrome): an uncommon finding in Benin City, Nigeria

Theodore states that the term 'masquerade syndrome' first appeared in the ophthalmic literature in 1967 to describe a conjunctival carcinoma that presented as chronic conjunctivitis. Since then, the masquerade syndrome label has been applied to a group of disorders that mimic ocular inflammatory disease. Although some benign conditions can be considered masquerade syndromes, most often the term refers to malignant entities. Tsai and O'Brien also report that ocular oncology, the subspecialty that concerns itself with ocular and orbital malignancies, is by nature a field of uncommon disorders. A discussion of the masquerade syndrome therefore becomes a study in uncommon presentations of uncommon diseases. Nevertheless, the subject deserves wide attention because, in many cases, the diseases that masquerade are not only vision-threatening but potentially fatal. Significant morbidity and mortality can be averted by early recognition and diagnosis of the masquerade. In this article, we present a case of a 78-year-old Nigerian woman who had an ocular melanoma that presented as a panophthalmitis, a rare case of masquerade syndrome in our environment.     

5-HT1-like receptor agonists enhance wakefulness.

The effects of four 5-HT1-like receptor agonists (8-OH-DPAT, RU 24969, BEA 1654 and 5-carboxamidotryptamine) and some putative 5-HT1-like receptor antagonists on vigilance were examined in an attempt to clarify the role of 5-HT1-like receptors in the sleep-waking pattern of rats. Both 8-OH-DPAT (0.5-2.0 mg/kg, s.c.) and RU 24969 (0.5-2.0 mg/kg, s.c.) increased wakefulness and the latencies of slow wave and rapid eye movement (REM) sleep. The slow wave and REM sleep were correspondingly decreased or completely abolished. The two other 5-HT1-like receptor agonists had either a slight (BEA 1654, 1.0-5.0 mg/kg, s.c.) or no (5-carboxamidotryptamine, 0.5-2.0 mg/kg, s.c.) effect on sleep pattern. The arousal effect of 8-OH-DPAT was further potentiated in rats pretreated with reserpine (2.5 mg/kg, i.p.; 18 hr before 8-OH-DPAT). The non-selective 5-HT1-like and 5-HT2 receptor antagonist, methiothepin (2.0 mg/kg, i.p.) and the beta-adrenoceptor antagonist propranolol (16.0 mg/kg, s.c.), which is a putative antagonist at 5-HT1A and 5-HT1B receptor subtypes, significantly potentiated the arousal effect of RU 24969. The putative 5-HT1A and 5-HT1B receptor antagonist, cyanopinolol (4.0 mg/kg, s.c.), mixed 5-HT1A receptor agonist/antagonist MDL 72832 (1.0 mg/kg, s.c.) and the alpha 1-adrenoceptor antagonist prazosin (2.0 mg/kg) did not affect the vigilance, altered by RU 24969. These results suggest that the arousal effect of 5-HT1-like receptor agonists is probably not mediated by any of the subtypes of 5-HT1-like receptors or by an activation of a noradrenergic system.     

Vernal keratoconjunctivitis in Nigerians: 109 consecutive cases

Vernal keratoconjunctivitis was the most common conjunctival disease seen over a 2 year period (January 1997-December 1998) at the University of Benin Teaching Hospital, Benin City, Nigeria. One hundred and nine consecutive patients were seen with vernal keratoconjunctivitis. There was a male to female ratio of 1:1.3. The age range of the patients was 5 months to 38 years with a mean age of 15.5 +/- 8.3 years (SD). Of the patients 54.1% were children. Itching was the most common symptom, followed by redness, tearing, aching eye and photophobia. Ninety patients (82.6%) had predominantly tarsal papillae, while the others had mixed and limbal papillae. A history of atopic diseases such as asthma and rhinitis was present in only five patients (4.5%). There was no patient with corneal ulcer or scarring. Although the complications were few, health education of the patients about the dangers of self medication with steroids should be emphasized.     

Functional reactivity of the dopaminergic system following acute and chronic ketamine treatments

This study examined the effects of acute (15 mg/kg, i.p.) and chronic subanesthetic (15 mg/kg, i.p., t.i.d, for 6 days) doses of ketamine [a noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist] on amphetamine (presynaptic dopamine releasing agent; 10 mg/kg, i.p.) and apomorphine (a D₂ receptor agonist; 1 mg/kg, i.p.)-induced stereotyped behaviors. The effect of acute and chronic ketamine on haloperidol (a D₂ receptor antagonist; 1.6 mg/kg, i.p.)-induced catalepsy was also examined. Acute ketamine and chronic ketamine pretreatment increased amphetamine-induced stereotyped sniffing and locomotion compared with control groups. Acute ketamine significantly increased apomorphine-induced stereotyped sniffing. However, chronic ketamine had no significant effect on apomorphine-induced stereotyped sniffing. Acute, but not chronic ketamine treatment abolished haloperidol-induced catalepsy. The increase in amphetamine-induced stereotyped behaviors and the reversal of haloperidol-induced catalepsy by acute ketamine suggest that blockade of NMDA receptors by ketamine facilitates dopaminergic transmission. The absence of significant effect of chronic ketamine on apomorphine-induced stereotyped sniffing and haloperidol-induced catalepsy suggests that chronic ketamine does not modulate postsynaptic dopaminergic D₂ receptors. It is suggested that chronic ketamine increased amphetamine-induced behaviors by causing hypersensitivity of presynaptic dopamine releasing mechanisms on dopaminergic terminals.     

Prevalence of HIV seropositivity among patients with squamous cell carcinoma of the conjunctiva

Objective

To determine the prevalence of HIV seropositivity among patients with squamous cell carcinoma of the conjunctiva.

Methods

All patients with clinical and histopathological confirmation of squamous cell carcinoma seen during a ten year period (July 1999 to June 2009) were tested for HIV (Human Immunodeficiency Virus). The number of patients with squamous cell carcinoma of the conjunctiva who are HIV positive were counted.

Results

A total of thirty-three(33) eyes in thirty-two(32) patients were confirmed histopathologically to have conjunctival squamous cell carcinoma. Their ages ranged from 22 years to 66 years with a mean age of (38.6±11.8) years (SD). The male to female ratio was 1:1.5. Twenty four (75%) of these patients were HIV positive.

Conclusions

Squamous cell carcinoma is associated with the human immunodeficiency virus and is thus a marker for the disease in Benin City, Nigeria.