Otolaryngologic aspects of lyme disease

Lyme disease is a systemic illness caused by the spirochete Borrelia burgdorferi and transmitted by the bite of a tick in the Iocodes ricinus complex. While the illness is often associated with a characteristic rash, erythema migrans, patients may also present with a variety of complaints in the absence of the rash. The otolaryngologist may be called upon to see both groups of patients, with any number of signs and symptoms referable to the head and neck, including headache, neck pain, odynophagia, cranial nerve palsy, head and neck dysesthesia, otalgia, tinnitus, hearing loss, vertigo, temporomandibular pain, lymphad-enopathy, and dysgeusia. We review our institutional experience with 266 patients with Lyme disease, 75% of whom experienced head and neck symptoms. We also summarize the diagnostic and treatment modalities for this illness.     

Prostate Development in Prune Belly Syndrome (PBS) and Posterior Urethral Valves (PUV): Etiology of PBS-Lower Urinary Tract Obstruction or Primary Mesenchymal Defect?

Prune belly syndrome (PBS) has been recognized since 1950 as the triad of absent abdominal wall musculature, undescended testes, and urinary tract anomalies. The etiology, however, remains uncertain. Theories of mesenchymal maldevelopment, obstruction, and genetic origin have been proposed. To evaluate the role of lower urinary tract obstruction as it relates to prostatic development and PBS, we studied the lower urinary tract of 15 cases of PBS, 8 cases of posterior urethral values (PUV), and 34 age-matched controls. It is generally accepted that prostatic growth and development are dependent on mesenchymal-epithelial interactions. We evaluated the mesenchymal and epithelial differentiation and relationships, and found distinctly different and consistent abnormalities between PBS and PUV as compared with one another and controls. The findings suggest that in PBS, prostatic growth and development are hindered because of destruction or absence of the appropriate primitive mesenchyme. Our studies could not definitely exclude very early obstruction as a cause of the findings because of lack of appropriate fetal material.     

Comparative study of roles of the lobus parolfactorius and intermediate medial hyperstriatum ventrale in memory formation in the chick brain.

Two discrete areas of the chick brain, the intermediate medial hyperstriatum ventrale (IMHV) and lobus parolfactorius (LPO), were found to have different functions during the formation of memory for a 1-trial peck-avoidance paradigm. Glutamate, ouabain, and emetine, known to disrupt short-, intermediate-, and long-term memory when injected into the IMHV, were injected into the cerebellum and LPO. All amnestic agents investigated produced amnesia when injected into the IMHV; only one of these agents produced amnesia when injected into the LPO, and none of the agents produced amnesia when injected into the cerebellum. The chick brain was also found to exhibit hemispheric asymmetries: The left IMHV and LPO were more sensitive to the amnestic agents than their corresponding right structure. From these data, hypotheses for the roles of these structures during memory are proposed.     

Regional preferences of AMPA receptor modulators determined through agonist binding autoradiography

Autoradiographic techniques were used to test if positive modulators of AMPA-type glutamate receptors have regionally differentiated effects on ligand binding. Cyclothiazide, a drug with ten fold greater effects on `flip' than `flop' splice variants of the receptors, had unequal effects across the subdivisions of hippocampus; i.e., it reduced [³H]AMPA binding in field CA3 with an EC₅₀ of 24 μM and in field CA1 and dentate gyrus with EC₅₀s between 60 and 100 μM. The EC₅₀ for the drug's influence on binding was also significantly lower in the superficial than in the deeper layers of the neocortex, though these differences were not as pronounced as those in the hippocampus. The ampakine CX614, a compound with a modest preference for flop variants, had a slightly lower EC₅₀ for its effects on [³H]AMPA binding in CA1 than in CA3. This result was confirmed with [³H]fluorowillardiine binding. The effects of the ampakine in neocortex tended to be greater in the deeper than superficial layers but this did not reach statistical significance. These results indicate that differential effects of modulators on AMPA receptor subunits are reflected in their relative potency across brain subdivisions. This raises the possibility that subclasses of positive modulators will exhibit a measurable degree of selectivity in their physiological and behavioral influences.     

HLA-DR expression in macaque neuroendothelial cells in vitro and during SIV encephalitis

HLA-DR expression in neuroendothelial cells (NEC) was studied during the course of SIV encephalitis in rhesus monkeys. HLA-DR determinants were detected on NEC in monkeys with SIV encephalitis, but not in control animals. In situ hybridization with an SIV probe indicated that HLA-DR expression was not a consequence of SIV replication within NEC. Cultured rhesus NEC stimulated with gamma interferon expressed HLA-DR to a higher degree than cultured brain fibroblasts or astrocytes. These data support the contention that NEC participate in retrovirus-induced inflammation and autoimmunity within the central nervous system.