Oral defense mechanisms are impaired early in HIV-1 infected patients.

We have examined the hypothesis that individuals infected with human immune deficiency virus type 1 (HIV-1) experience significant, specific alterations in mechanisms protecting the oral cavity prior to the appearance of AIDS-related systemic opportunistic infections. In a study of 13 early-stage, stable anti-HIV antibody positive patients, parotid salivary function was found to be generally intact. In contrast, several indicators of submandibular gland dysfunction were detected. In particular, stimulated fluid output was decreased and salivary lysozyme levels were increased relative to controls by 50-60% for both resting (p less than 0.05) and stimulated (p less than 0.001) conditions. Also, the frequency of albumin detection in submandibular saliva samples was approximately 65% in HIV-1 infected patients vs. 0% in controls (p less than 0.05). In addition, cytologic evaluation of oral mucosa revealed a fivefold increase in the prevalence of candidal hyphae in HIV-1 infected patients compared to controls (41% vs. 8%, p less than 0.05). We conclude that normal oral defense mechanisms show signs of compromise in HIV-1 infected individuals. We suggest that (a) effects of HIV-1 infection are seen early in the oral cavity, (b) impairment of oral defense mechanisms may facilitate entry of microorganisms with an attendant increased risk of morbidity and mortality, and (c) intensive oral surveillance and prophylactic care should be part of the routine management afforded to AIDS patients soon after HIV-1 infection is recognized.

Individual specimen triage of effusion samples: an improvement in the standard of practice, or a waste of resources?

The standard of practice in cytopathology does not include an individual specimen triage (IST) for sample optimization, but rather prescribes a uniform procedure, e.g., for smears, cell blocks, and cytospins. IST requires additional resources. We sought to evaluate whether IST would result in enhanced diagnostic accuracy and specimen turnaround time in effusions. In order to evaluate the efficacy of IST, 50 effusion samples (31 pleural, 16 peritoneal, and 3 pericardial), each with a minimum volume of 50 ml, were utilized. Each sample was prepared via IST to include at least two initial prepared Diff-Quik-stained cytospins on which the IST was based, as well as a standard cytopreparation protocol for nontriaged samples (NTS) which was limited to 3 smears (2 Papanicolaou-stained, and 1 Diff-Quik-stained) and a hematoxylin-eosin (H&E)-stained cell block section. All triaged and NTS were reviewed retrospectively to determine if IST offered any advantages over the standard cytopreparation protocol for effusion samples. Each was evaluated for diagnostic concordance, turnaround time for final diagnosis, and optimal preparation. In 46 cases, diagnoses in IST and NTS were 100% concordant. Four cases showed minor discrepancies between the original and the NTS diagnoses. In general, the discordant cases were due to sparse cellularity in a specimen composed largely of blood. There was no difference in turnaround time for final diagnosis. Based on a review of all samples, the combination of cell block preparation and cytospins (stained with Diff-Quik and Papanicolaou stains) were considered optimal for microscopic evaluation. IST offers no practical advantage over the NTS standard specimen preparation in relation to the accuracy of final diagnosis or turnaround time. The lysing of grossly bloody fluids with subsequent preparation of cytospins yielded superior preparations for microscopic evaluation over NTS. The standard preparation of effusion samples should include the preparation of a cell block, and cytospins stained with Diff-Quik and Papanicolaou stains, for optimal microscopic evaluation.

Coordinated, multi-joint, fatigue-resistant feline stance produced with intrafascicular hind limb nerve stimulation.

The production of graceful skeletal movements requires coordinated activation of multiple muscles that produce torques around multiple joints. The work described herein is focused on one such movement, stance, that requires coordinated activation of extensor muscles acting around the hip, knee and ankle joints. The forces evoked in these muscles by external stimulation all have a complex dependence on muscle length and shortening velocities, and some of these muscles are biarticular. In order to recreate sit-to-stand maneuvers in the anesthetized feline, we excited the hind limb musculature using intrafascicular multielectrode stimulation (IFMS) of the muscular branch of the sciatic nerve, the femoral nerve and the main branch of the sciatic nerve. Stimulation was achieved with either acutely or chronically implanted Utah Slanted Electrode Arrays (USEAs) via subsets of electrodes (1) that activated motor units in the extensor muscles of the hip, knee and ankle joints, (2) that were able to evoke large extension forces and (3) that manifested minimal coactivation of the targeted motor units. Three hind limb force-generation strategies were investigated, including sequential activation of independent motor units to increase force, and interleaved or simultaneous IFMS of three sets of six or more USEA electrodes that excited the hip, knee and ankle extensors. All force-generation strategies evoked stance, but the interleaved IFMS strategy also reduced muscle fatigue produced by repeated sit-to-stand maneuvers compared with fatigue produced by simultaneous activation of different motor neuron pools. These results demonstrate the use of interleaved IFMS as a means to recreate coordinated, fatigue-resistant multi-joint muscle forces in the unilateral hind limb. This muscle activation paradigm could provide a promising neuroprosthetic approach for the restoration of sit-to-stand transitions in individuals who are paralyzed by spinal cord injury, stroke or disease.

Squamous atypia in the atrophic cervical vaginal smear: a new look at an old problem.

BACKGROUND: Squamous atypia in postmenopausal (PM) cervical vaginal smears (CVS) only rarely is associated with a biopsy-proven squamous intraepithelial lesion (SIL), and thus most commonly represents an atrophy-associated benign reactive change. METHODS: To distinguish atypical squamous cells of undetermined significance (ASCUS) and SIL from atrophy-associated benign reactive changes, a review of atypical atrophic PM CVS was performed. Ninety CVS exhibiting an atrophic smear pattern were considered appropriate for study. Repeat smears and/or biopsy after local estrogen therapy were requested to distinguish atrophic/reactive from dysplastic changes. RESULTS: Generally, atrophic CVS exhibit uniform nuclear enlargement in the squamous cell population, which, using the criterion of nuclear enlargement alone, would qualify the majority of these cases to be classified as ASCUS. The nuclear enlargement associated with atrophy resolves with the local application of estrogen. Follow-up after local estrogen treatment was available for 84 of 90 patients and revealed 10 cases of SIL (12%) and 9 cases of ASCUS (11%), 6 of which were favored to be of a reactive etiology. Nuclear features most commonly noted in the cases considered to be ASCUS (nonreactive) and SIL were nuclear hyperchromasia and nuclear contour irregularities. CONCLUSIONS: Nuclear enlargement alone is not sufficient for diagnosing ASCUS or SIL in PM CVS. Nuclear enlargement in squamous cells is an expected normal reactive change present in PM CVS that resolves with the application of local estrogen. Nuclear hyperchromasia and irregular nuclear contours remain the most reliable cellular characteristics for diagnosing SIL in atrophic CVS.

Effusion cytology of malignant melanoma. A morphologic and immunocytochemical analysis including application of the MART-1 antibody.

BACKGROUND: Malignant effusions are complications of metastatic malignant melanoma (MM). Differential diagnosis often involves distinguishing MM from adenocarcinoma and reactive mesothelial cells. Descriptions in the literature of the morphologic and immunocytochemical (IM) staining characteristics of MM in effusions are sparse. A combination of morphology and immunocytochemistry should yield the most accurate diagnostic results. The MART-1 antigen, a transmembrane protein, is specifically expressed in melanocytes and MM. A recently developed monoclonal antibody to the MART-1 antigen may represent a useful marker for the identification of MM in effusions. METHODS: The authors conducted a retrospective review of 32 effusion samples diagnosed as MM. The review consisted of morphologic and IM analyses of the effusion samples with antibodies to MART 1, HMB45, S-100, and cytokeratins (AE1/ AE3). IM stains were performed on cell block or cytospin material, depending on availability. In the morphologic review, emphasis was placed on Diff Quik-stained material, due to its enhanced cytoplasmic volume and detail. RESULTS: Predominant cytologic features noted were lack of cellular cohesion (in 100% of cases), large eccentric nuclei with prominent nucleoli (in 100%), multinucleation (in 84%), variable cytoplasmic vacuolization (in 75%), pigment (in 72%), and cell-in-cell engulfment (in 47%). All immunoreactive cases with sufficient material stained with at least one of the markers used. Tumor cells were positive with IM stains to MART-1 in 78% of cases, HMB45 in 81%, and S-100 in 81%. Coexpression of MART-1, HMB45, and S-100 was noted in 63% of cases. Of cases that showed expression for only 1 of the 3 antigens, the MART-1 was positive in 1 case, and HMB45 and S-100 were positive in 2 cases each. Three cases showed immunoreactivity for cytokeratins in the melanoma cells. CONCLUSIONS: The diagnosis of MM in effusions can be made reliably through a combination of morphologic and IM features. Differential diagnosis often involves distinguishing MM from adenocarcinoma or reactive mesothelial cells. Cytoplasmic vacuolization, multinucleation, prominent nucleoli, and cell-in-cell engulfment are cytologic features common to all three. The lack of IM staining for cytokeratins alone cannot reliably distinguish MM; 11% of cases showed positive staining with this antibody in the melanoma cells. The use of a panel of antibodies increases the accuracy of diagnosing MM. In this study, MART-1 proved a useful adjunct to the HMB45/S-100/cytokeratin panel for the diagnosis of MM in effusions, staining 78% of the immunoreactive cases, with positivity in 1 case that was negative for HMB45 and S-100.