Destructive ocular myiasis in a noncompromised host

A case of destructive ocular myiasis resulting in complete loss of the globe in two days time is documented. To the best of our knowledge this is the first report of such a severe involvement in a healthy and non-compromised host. Mechanical removal and good local hygiene helped heal the wound. The larvae were isolated to be that of Chrysomyia bezziana (screwworm fly). This is possibly the first report of destructive ocular myiasis caused by Chrysomyia bezziana from the Indian subcontinent and the second in world literature. Infestation of human eyes with larvae of flies (myiasis) has been reported. Serious consequences of destructive myiasis are seen in emaciated and diseased patients. Only one report of total destruction of the globe by maggots of Chrysomyia bezziana exists in the literature. As in previous communications, the patient in this report had no predisposing factors both systemic and local. We here in document a case of orbital myiasis leading to rapid destruction of the globe within two days in a healthy and a non-compromised patient.     

Endoscopic sclerotherapy in the treatment of gastric varices

Of 309 patients with portal hypertension, gastric varices were found in 48 (16 per cent). While the majority (88 per cent) of the patients had gastric varices in association with oesophageal varices, 6 (12 per cent) patients had 'isolated' gastric varices. Gastric varices were seen significantly (P less than 0.01) more often with grade 4 than with grade 3 varices. In 11 (28 per cent) of the 40 patients who completed sclerotherapy for oesophageal varices, gastric varices disappeared concurrently on eradication of oesophageal varices or during the following 6 months. Of the initial five patients with gastric varices who received direct intravariceal injections, four rebled; this technique was therefore replaced by combination (paravariceal + intravariceal) gastric variceal sclerotherapy. Emergency combination sclerotherapy successfully controlled bleeding from gastric varices in six of the eight treated patients. Thirty-two patients entered a programme of elective combination gastric variceal sclerotherapy. Variceal obliteration was achieved in 12 cases (38 per cent) and reduction in size was noted in another 7 patients (22 per cent) after a minimum of four courses. There were 11 (23 per cent) deaths, 8 due to uncontrolled bleeding from gastric varices and 3 due to hepatic coma. The other complications of gastric variceal sclerotherapy were minor and included retrosternal pain, fever and dysphagia. It is concluded that gastric varices often coexist with large oesophageal varices. If they persist for 6 months after eradication of oesophageal varices, a combination of paravariceal and intravariceal sclerotherapy should be attempted for their obliteration.     

Divergent movement of adjacent whiskers

The current view of whisker movement is that approximately 25 whiskers on each side of the face move in synchrony. To determine whether whiskers are constrained to move together, we trained rats to use two whiskers on the same side of the face in simple behavioral tasks and videotaped the whiskers during the task. Here we report that the movement of adjacent whiskers is usually synchronous but can diverge: 1) the distance between whiskers can vary dramatically during movement; 2) one whisker can move while the second one remains stationary; 3) two whiskers can simultaneously move in opposite directions; and 4) one whisker can be maintained in contact with an object while the other is retracted and protracted. The frequency of whisker movement during the task falls within the previously reported range for rats whisking freely into air or performing roughness discrimination with their whiskers. Our data also suggest that whisker movement can be divided into three distinct phases: protraction, retraction, and a measurable delay between these movements. We conclude that, although whiskers often move in concert, adjacent caudal whiskers can be moved independently of each other.     

Epidural mass due to aspergillus flavus causing spinal cord compression--a case report and brief update

Aspergillus infection of the central nervous system (CNS) is an uncommon disease. Most of the reported cases are of sinocranial spread and cases with contiguous spread to spinal cord from lung and other organs are uncommon. A case of pulmonary aspergillosis with extension to thoracic vertebrae forming a paraspinal mass resulting in neurological deficit due to Aspergillus flavus, is reported. The 43 year old patient did not have any obvious predisposing condition. He presented with loss of motor function and succumbed to the infection despite operative intervention and antifungal therapy. A brief update on CNS aspergillosis is presented along with detailed clinical, radiological and laboratory work up of the patient.     

Receptive fields and response properties of neurons in the star-nosed mole's somatosensory fovea

Star-nosed moles have an extraordinary mechanosensory system consisting of 22 densely innervated nasal appendages covered with thousands of sensitive touch domes. A single appendage acts as the fovea and the star is constantly shifted to touch this foveal appendage to objects of interest. Here we investigated the receptive fields on the star and the response properties of 144 neurons in the mole's primary somatosensory cortex (S1). Excitatory receptive fields were defined by recording multiunit activity from the S1 representations of the nasal appendages that form the star, while stimulating the touch domes on the skin surface with a small probe. Receptive fields were among the smallest reported for mammalian glabrous skin, averaging <1 mm(2). The smallest receptive fields were found for the fovea representation, corresponding to its greater cortical magnification. Single units were then isolated, primarily from the representation of the somatosensory fovea, and the skin surface was stimulated with a small probe attached to a piezoelectric wafer controlled by a computer interface. The response properties of neurons and the locations of inhibitory surrounds were evaluated with two complementary approaches. In the first set of experiments, single microelectrodes were used to isolate unit activity in S1, and data were collected for stimulation to different areas of the sensory star. In the second set of experiments, a multi-electrode array (4 electrodes spaced at 200 microm in a linear sequence) was used to simultaneously record from isolated units in different cortical areas representing different parts of the sensory periphery. These experiments revealed a short-latency excitatory discharge to stimulation of the fovea followed by a long-lasting suppression of spontaneous activity. Sixty-one percent of neurons responded with an excitatory OFF response at the end of the stimulus; the remaining 39% of cells did not respond or were inhibited at stimulus offset. Stimulation of areas surrounding the central receptive field often revealed inhibitory surrounds. Forty percent of the neurons that responded to mechanosensory stimulation of the receptive field center were inhibited by stimulation of surrounding areas of skin on the same appendage. In contrast to neurons in rodent barrels, few neurons within a stripe representing an appendage responded to stimulation of neighboring (nonprimary) appendages on the snout. The small receptive fields, short latencies, and inhibitory surrounds are consistent with the star's role in rapidly determining the locations and identities of objects in a complex tactile environment.