Neurologic sequelae of domoic acid intoxication due to the ingestion of contaminated mussels

In late 1987 there was an outbreak in Canada of gastrointestinal and neurologic symptoms after the consumption of mussels found to be contaminated with domoic acid, which is structurally related to the excitatory neurotransmitter glutamate. We studied the neurologic manifestations in 14 of the more severely affected patients and assessed the neuropathological findings in 4 others who died within four months of ingesting the mussels. In the acute phase of mussel-induced intoxication, the patients had headache, seizures, hemiparesis, ophthalmoplegia, and abnormalities of arousal ranging from agitation to coma. On neuropsychological testing several months later, 12 of the patients had severe anterograde-memory deficits, with relative preservation of other cognitive functions. Eleven patients had clinical and electromyographic evidence of pure motor or sensorimotor neuronopathy or axonopathy. Positron-emission tomography of four patients showed decreased glucose metabolism in the medial temporal lobes. Neuropathological studies in the four patients who died after mussel-induced intoxication demonstrated neuronal necrosis and loss, predominantly in the hippocampus and amygdala, in a pattern similar to that observed experimentally in animals after the administration of kainic acid, which is also structurally similar to glutamate and domoic acid. We conclude that intoxication with domoic acid causes a novel and distinct clinicopathologic syndrome characterized initially by widespread neurologic dysfunction and then by chronic residual memory deficits and motor neuronopathy or axonopathy.     

Lysosomal storage in human skeletal muscle

Skeletal muscle is involved symptomatically in two lysosomal storage diseases, acid maltase deficiency and a similar condition in which enzyme levels are normal. Asymptomatic storage in skeletal muscle cells is found in Batten-Kufs' disease (ceroid lipofuscinosis), Fabry's disease, and mannosidosis, as well as in rare patients with an unidentified storage disease. Other cell types (vascular endothelium, smooth muscle, fibroblasts, satellite cells) within the confines of the biopsy specimen may reveal storage in other diseases. The differential diagnosis involves predominantly both normal and abnormal conditions in which acid phosphatase activity is prominent in cells.     

Characterization of acaricide resistance in Rhipicephalus sanguineus (latreille) (Acari: Ixodidae) collected from the Corozal Army Veterinary Quarantine Center, Panama

Rhipicephalus sanguineus (Latreille) were collected from the Corozal Army Veterinary Quarantine Center in Panama and characterized for resistance to five classes of acaricides. These ticks were highly resistant to permethrin, DDT, and coumaphos; moderately resistant to amitraz; and not resistant to fipronil when compared with susceptible strains. Resistance to both permethrin and DDT may result from a mutation of the sodium channel. However, synergist studies indicate that enzyme activity is involved. The LC50 estimate for permethrin was lowered further in the Panamanian strain then in susceptible strains with the addition of triphenylphosphate (TPP), but not with the addition ofpiperonyl butoxide (PBO). This suggests that esterases and not oxidases are responsible for at least some pyrethroid resistance. Elevated esterase activity and its inhibition by TPP were confirmed by native gel electrophoresis. The LC50 estimate obtained for coumaphos in the Panamanian strain was not lowered further than what was observed for susceptible strains by the addition of TPP or PBO. This indicates that enzyme activity might not be involved in coumaphos resistance. Resistance to amitraz was measured through a modification of the Food and Agriculture Organization Larval Packet Test. All tick strains were found to be susceptible to fipronil.     

Immunologic enhancement of rat renal allografts. III. Immunopathologic lesions and rejection in long-surviving passively enhanced grafts.

Immunologic enhancement of renal allografts from (Lewis times Brown Norway) F1 to Lewis rats was achieved by administering a single dose of antidonor serum at the time of transplantation. A series of grafts functioning for 1 to 4 months after transplantation were examined by light and immunofluorescence microscopy to evaluate the long-term protective effects of the enhancing serum and to determine if previously unobserved lesions appeared in long survivors. Despite the absence of detectable circulating cytotoxic alloantibody, long-term allografts showed necrotizing glomerular and arterial lesions which resembled those seen in acutely rejecting grafts and were compatible with humoral rejection. Thus, in this model, there is a late decline in the ability of passive enhancement to inhibit humoral rejection. Long-term grafts also developed tubular lesions with deposition of immunoglobulin and complement on the tubular basement membranes (TBM). Anti-TBM antibodies were demonstrated in recipients' sera and found to be organ specific but not major histocompatibility antigen or species specific. This tubular lesion is therefore a unique form of allograft injury in which the immune response is directed against tissue antigen(s) which are distinct from the major histocompatibility antigens that induce rejection.     

Properties of a filamentous virus of the honey bee (Apis mellifera)

An ellipsoidal particle, measuring 450 x 150 nm, from honey bees comprises a nucleocapsid measuring 3000 x 40 nm, containing double-stranded DNA with a molecular weight of approximately 12 x 10(6), which is coiled within a membrane. The buoyant densities in CsCl of the whole particle, nucleocapsid, DNA and DNA with ethidium bromide are 1.28, 1.36, 1.71 and 1.61 g/ml, respectively. The particle contains about 12 proteins, with molecular weights ranging from 13,000 to 70,000, which are distributed approximately equally between the membrane and the nucleocapsid.     

Mucolipidosis type IV: clinical manifestations and natural history.

The clinical manifestations and psychomotor development of five patients with mucolipidosis IV (MLIV) from three Ashkenazi-Jewish families are reported. The presenting symptoms were hypotonia, developmental delay, corneal clouding, and puffy eyelids. Four of the patients had convergent strabismus and none progressed beyond a developmental age of 15 months. One patient died of aspiration at 17 years while the oldest patient entered puberty at 20 years, developed a coarse face at 30 years, and is now 32 years old. Histopathological studies in four patients showed storage changes characteristic of MLIV.     

Vestibular projections to the nuclei of the extraocular muscles Degeneration resulting from discrete partial lesions of the vestibular nuclei in the monkey

In 35 monkeys attempts were made to produce localized unilateral lesions in individual vestibular nuclei in order to study vestibular projections to nuclei of the extraocular muscles. Portions of the medial, superior and inferior vestibular nuclei were destroyed selectively; lesions in Deiters' nucleus involved small portions of either the superior or inferior vestibular nuclei. Fiber degeneration was studied by the Nauta-Gygax technic. Exclusively ascending fibers from the superior vestibular nucleus project to ipsilateral extraocular nuclei. Ascending fibers from the inferior vestibular arise only from rostral portions of the nucleus, are not numerous and pass to all extraocular nuclei. The medial vestibular nucleus projects ascending fibers via the MLF bilaterally, asymmetrically and differentially to all extraocular nuclei. Prominent projections pass to: (a) the contralateral trochlear nucleus, and (b) the contralateral intermediate cell column and the ipsilateral ventral nucleus of the oculomotor complex. Ascending fibers from Deiters' nucleus, arising only from ventral portions of the nucleus, project primarily to: (a) the contralateral abducens and trochlear nuclei, and (b) specific asymmetrical portions of the oculomotor complex. Ascending vestibular fibers from the medial and lateral vestibular nuclei appear capable of mediating all patterned eye movements resulting from stimulation of ampullary nerves from individual semicircular canals. Vestibular projections to nuclei of the extraocular muscles are most abundant to those nuclei innervating muscles whose primary functions concern horizontal and rotatory eye movements.