Inhibition of factor VIIa-tissue factor coagulation activity by a hybrid protein.

Lipoprotein-associated coagulation inhibitor (LACI) appears to inhibit tissue factor (TF)-induced blood coagulation by forming a quaternary inhibitory complex containing factor Xa, LACI, factor VIIa, and TF. A genetically engineered hybrid protein consisting of the light chain of factor Xa and the first Kunitz-type inhibitor domain of LACI is shown to directly inhibit the activity of the factor VIIa-TF catalytic complex. Unlike inhibition of factor VIIa-TF activity by native LACI, inhibition by the hybrid protein is not dependent on factor Xa. In an assay of TF-induced coagulation, 50% TF inhibition occurs with hybrid protein at 35 nanograms per milliliter, whereas LACI at 2.5 micrograms per milliliter is required for an equivalent effect. gamma-Carboxylation of glutamic acid residues in the factor Xa light chain portion of the hybrid protein is required for inhibitory activity, indicating that the first Kunitz-type domain of LACI alone is not sufficient for inhibition of factor VIIa-TF.

The identification and tracking of Candida albicans isolates from oral lesions in HIV-seropositive individuals.

Restriction fragment polymorphism analysis was used to investigate the identity and genotypic relatedness of Candida albicans strains isolated from human immunodeficiency virus (HIV)-infected patients with or without oral candidiasis and from some of their sexual partners. Use of the species-specific DNA probe Ca3 revealed that most subjects carried a single distinct C. albicans strain throughout the course of the study, during both symptomatic and asymptomatic periods. Sexual partners were more likely to carry the same or similar C. albicans isolates than unrelated subjects, raising the possibility of transmission via intimate contact. One patient appeared to acquire his partner's isolate, which then became predominant in both partners in subsequent isolations. These findings indicate that recurrent oral candidiasis is usually caused by a single persistent strain unique to each patient, but that in some cases transmission via intimate contact may occur between sexual partners.

A study of macrophages, macrophage-related cells, and endothelial adhesion molecules in recurrent aphthous ulcers in HIV-positive patients.

The purpose of this immunohistochemical study was to investigate the presence and distribution of macrophages (CD11c+ and CD68+) and macrophage-related dendritic cells (factor XIIIa+ and CD36+) in early and late aphthous ulcers associated with HIV infection. To substantiate a mechanism by which these cells may move from the vascular compartment to tissue spaces, we also investigated expression of ELAM (endothelial leukocyte adhesion molecule), ICAM-1 (intercellular adhesion molecule), and CD18 (leukocyte function antigen). Numerous CD11c+ and CD68+ macrophages were seen in early lesions, though larger numbers of CD68+ cells were present in older lesions. No significant increases in factor XIIIa+ dendrocytes were seen in either early or late lesions, though dendrocytes appeared enlarged. CD36+ cells and CD18+ leukocytes were more numerous in early than in late aphthous ulcers. ELAM and ICAM expression was most intense on endothelial cells in early aphthous ulcers, with staining intensity fading toward the lesion periphery. Control specimens showed weaker ELAM and ICAM staining than did the ulcer specimens. Keratinocytes did not express ICAM. By virtue of their numbers, macrophages and macrophage subtypes appear to have a significant role in both the early and late stages of this disease. Although factor XIIIa-expressing dendrocytes may not have been more numerous in the ulcers, they appeared to be "activated" because of their prominence in the lesions and their occasional co-expression of CD68 antigen (KP1+). They may have a minor role in antigen processing, phagocytosis, and fibroplasia. ELAM and ICAM expression by endothelial cells provides a mechanism by which macrophages and other leukocytes can be recruited to the site of the lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Incidence of oral lesions in HIV-1-infected women: reduction with HAART.

Few studies assess the effectiveness of HAART on reducing the incidence and recurrence of oral lesions. We investigated such changes among 503 HIV+ women over six years in the Women's Interagency HIV Study. The incidence of erythematous candidiasis (EC), pseudomembranous candidiasis (PC), hairy leukoplakia (HL), and warts was computed over follow-up visits after HAART initiation compared with before HAART initiation. Analysis of our data demonstrates a strong decrease in candidiasis after HAART initiation. The incidence of EC fell to 2.99% from 5.48% (RR 0.545); PC fell to 2.85% from 6.70% (RR 0.425); and EC or PC fell to 3.43% from 7.35% (RR 0.466). No changes were seen in HL or warts. Higher HIV-RNA was associated with greater incidence of candidiasis and HL, but not warts. Analysis of these data indicates that recurrence and incidence of candidiasis are reduced by HAART, and that recurrence is reduced independently of CD4 and HIV-RNA.

Expression of laminin 5, fibronectin, and epithelium-associated integrins in recurrent aphthous ulcers.

Recurrent aphthous ulceration (RAU) is characterized by an ulcerated lesion that persists longer than traumatic ulcers of similar size. This delayed healing phase of the lesion was investigated for extracellular matrix components and matrix receptors (integrins). The hypothesis tested was that aphthous ulcers may lack key extracellular matrix components, or their receptors, that are necessary for the migration of marginal keratinocytes from the ulcer edge. We immunocytochemically stained biopsy specimens of RAUs and non-involved mucosal specimens from HIV+ and non-infected individuals to investigate the presence and distribution of molecules reported to be associated with reepithelialization of mucosal and cutaneous wounds. Fibronectin, laminin type 5 (kalinin), and integrin subunits beta 1, beta 4, alpha 6, and alpha v were consistently found at the margins of RAU, as they are in traumatic ulcers. The alpha 5 and beta 6 subunits were not always present. We also found alpha v in the intact stratified squamous epithelium adjacent to ulcers. Immunohistochemical stains showed distruption in the deposition of laminin 5 and an apparent lack of fibronectin at the edges of some ulcers. Although these tissue results do not determine which integrin subunits are paired with each other, they do show some alterations in their expression in RAU. Absence of one or more of these molecules at the migrating front may contribute to delayed epithelial regeneration. It is likely that the absence or inappropriate expression of keratinocyte integrins or their extracellular matrix receptors occurs after the causative factors (currently unknown) of the lesion are gone. The reason for the altered expression of these molecules may be related to the secretory products (including lymphokines and proteinases) of the lymphocytic infiltrate.

Accuracy of diagnoses of HIV-related oral lesions by medical clinicians. Findings from the Women's Interagency HIV Study.

OBJECTIVE: To determine if medical clinicians are as accurate as dental clinicians in recognizing diagnostic characteristics of HIV-related oral lesions. METHODS: In 355 HIV-infected participants at five Women's Interagency HIV Study sites, we paired oral examinations conducted within 7 days of each other by dental and medical clinicians. We used the former as a gold standard against which to evaluate the accuracy of the latter. We assessed the accuracy of the medical clinicians' findings based both on their observations of abnormalities and on their descriptions of these abnormalities. RESULTS: Dental clinicians diagnosed some oral abnormality in 38% of participants. When "abnormality" was used as the medical clinicians' outcome, sensitivities were 75% for pseudomembranous candidiasis and 58% for erythematous candidiasis, but only 40% for hairy leukoplakia. When a precise description of the abnormality was used as their outcome, sensitivities were 19%, 12% and 20%, respectively. CONCLUSIONS: Medical clinicians recognize that HIV-related oral abnormalities are present in 40-75% of cases, but less often describe them accurately. Low sensitivity implies that the true associations of specific oral lesions with other HIV phenomena, such as time until AIDS, must be stronger than the literature suggests.

Vascular adhesion molecules in oral lichen planus.

OBJECTIVE: Because recruitment and retention of lymphoid cells appear to be critical components of the pathogenesis of lichen planus, we have compared the expression and distribution of a panel of vascular adhesion molecules (ELAM-1, P-selectin, ICAM-1, VCAM-1, PECAM-1, CD34) and leukocyte adhesion molecule ligands (LFA-1, Mac-1, VLA4, L-selectin) in biopsies of this disease. STUDY-DESIGN: Frozen sections of 12 clinically and histologically confirmed cases of lichen planus and 9 normal control tissues were evaluated immunohistochemically with a standard 1-day avidin-biotin peroxidase technique. Staining intensity of vascular endothelium was evaluated semiquantitatively. Three microvascular zones or compartments were defined and evaluated separately. RESULTS: Generally, different staining patterns were observed in association with the various endothelium-associated adhesion molecules. In normal controls, PECAM was intensely expressed and VCAM-1 was weakly expressed. Intermediate staining was associated with ELAM-1, P-selectin, ICAM-1, and CD34. Staining within the three microvascular compartments frequently showed variations in intensity. In lichen planus, increased staining for ELAM-1, P-selectin, ICAM-1, and VCAM-1 was evident in one or more of the microvascular compartments. In the subepithelial vascular compartment where the infiltrate was the most dense, VCAM-1 appeared to show the greatest positive change. Almost all cells in the lichen planus infiltrates stained positive for ICAM-1, L-selectin, LFA-1, and VLA4, and large numbers of cells also exhibited VCAM-1, PECAM-1, and Mac-1 immunoreactivity. CONCLUSIONS: It appears that upregulation of ELAM-1, ICAM-1, and VCAM-1 (especially by endothelial cells in the subepithelial vascular plexus) could play a role in the pathogenesis of lichen planus. The expression of leukocyte receptors L-selectin, LFA-1, and VLA4 by most of the cells in the lichen planus infiltrate suggest that these molecules may be responsible for recruitment as well as retention in the active lichen planus lesion.

Direct immunofluorescence vs. culture for detecting HSV in oral ulcers: a comparison.

Diagnostic tests may be necessary to determine the cause of oral ulcers. Direct immunofluorescence staining of oral smears supplies results much more quickly than viral culture, the "gold standard" for diagnosing HSV lesions. This study compares the sensitivity and specificity of direct immunofluorescence staining vs. viral culture and evaluates the usefulness of the two techniques for the general dental practitioner.

Oral ulceration in HIV infection: investigation and pathogenesis.

Oral ulcerations associated with HIV infection include recurrent aphthous ulcers (RAU). Whereas RAU prevalence is not increased, lesion severity is: among a group of HIV+ patients, 66% had the more severe herpetiform or major RAU. This increased severity suggests that HIV disease-related changes in the immune system may exacerbate RAU. In the peripheral blood of healthy subjects with RAU, CD4:CD8 cell ratios may be reversed and the proportion of T cell receptor-gamma delta + cells increased. HIV disease-related immune system changes are characterized by reversed CD4:CD8, lowered CD4 cell counts and an inverse correlation between CD4 cell counts and per cent activated gamma delta lymphocytes. Adhesion molecules and cytokines involved in lymphocyte homing may be important in RAU pathogenesis: ICAM-I and ELAM are strongly expressed, and TNF alpha production is increased in peripheral blood lymphocytes of healthy patients with RAU. In patients with active HIV disease/AIDS, serum TNF alpha levels are increased. Thalidomide, which inhibits TNF alpha production, is effective treatment for RAU. Some RAU patients have vitamin B12 or folate deficiencies, levels of which are commonly low in HIV+/AIDS patients. However, in a case control study of HIV+ patients, vitamin B12- or folate-deficiencies were not found to be significant risk factors for RAU.

Structure and activity of salivary gland chromosomes of Drosophila gibberosa.

In Drosophila gibberosa the maximum secretory output of the salivary glands is in the prepupa rather than in the late third-instar larva. Using salivary chromosome maps provided here we have followed puff patterns from late second-instar larvae through the time of histolysis of the salivary glands 28-32 h after pupariation and find low puff activity correlated with low secretory activity throughout much of the third larval instar. Ecdysteroid-sensitive puffs were not observed at the second larval molt but do appear prior to pupariation initiating an intense cycle of gene activity. The second cycle of ecdysteroid-induced gene activity a day later, at the time of pupation, appears somewhat damped, especially for late puffs. Salivary chromosome maps provided here may also be used to identify homologous loci in fat body, Malpighian, and midgut chromosomes.

Recurrent aphthous ulcers in association with HIV infection. Diagnosis and treatment.

Recurrent aphthous ulcers in patients with HIV infection can cause significant morbidity, which makes successful diagnosis and treatment imperative. We have found that the diagnostic paradigm for recurrent aphthous ulcers in HIV-seronegative patients, which is based on the ulcers' clinical appearance, location, absence of other ulcer-causing pathogens or pathogenic processes, and response to therapy, may be successfully applied to recurrent aphthous ulcers in HIV-infected patients. However, one must be alert for ulcers with uncommon causes as well as ulcers with common causes that have atypical clinical appearances that may mimic recurrent aphthous ulcers. The topical glucocorticoids, which are used to treat recurrent aphthous ulcers in HIV-seronegative patients, proved very effective in HIV-infected patients for treatment of herpetiform and minor ulcers and most major ulcers and were without notable side effects. A few severe cases of major recurrent aphthous ulcers required treatment with systemic prednisone, and some side effects were encountered.

Macrophages and vascular adhesion molecules in oral Kaposi's sarcoma.

Kaposi's sarcoma (KS) is a heterogeneous tumor where spindle cells are predominant and macrophages and factor XIIIa positive dendrocytes are abundant. The origin of the macrophages and dendrocytes is unclear, although their numbers suggest a critical role in KS pathogenesis. To determine if KS macrophages are recruited from the blood stream or proliferate on-site, we examined biopsy specimens 1) for expression and distribution of vascular adhesion molecules (PECAM-1, ELAM-1, ICAM-1, VCAM-1, P-selectin, L-selectin) and the macrophage-associated adhesion-molecule ligand, VLA-4; 2) for dual expression of proliferation (Ki-67) and lineage-associated markers (KP-1, CD34, factor XIIIa, LCA); and 3) for dual expression of macrophage (KP-1) and endothelial cell (CD34) associated markers. Avidinbiotin peroxidase techniques were used. Resident vessels were found to strongly express PECAM-1, ELAM-1, ICAM-1, P-selectin, and moderately express VCAM-1 and VLA-4. Tumor spindle cells showed less intense expression of ELAM-1, ICAM-1 and P-selectin. The most frequent double-stain combination was Ki-67 + CD34+. In contrast, the combinations of Ki-67 + KP-1+, Ki-67 + XIIIa+ and Ki-67 + LCA+ were rarely seen. The enhanced expression of adhesion molecules on resident vessels and the lack of evidence of macrophage proliferation suggest that the abundant macrophages in KS are recruited from the blood stream.

Acyclovir-resistant, foscarnet-sensitive oral herpes simplex type 2 lesion in a patient with AIDS.

We report the case of an immunocompromised patient with AIDS in whom developed a perioral and several intraoral HSV 2 lesions that persisted for more than 1 year. The virus was resistant to acyclovir but was sensitive to foscarnet. Viral isolates were thymidine kinase negative. The lesions resolved with intravenous foscarnet therapy given over a 15-week period, and when last seen, 8 months after foscarnet was discontinued, the patient had not had a recurrence.

Prophylaxis with nystatin pastilles for HIV-associated oral candidiasis.

To determine whether daily use of nystatin pastilles can prevent initial outbreak or recurrence of oral candidiasis in HIV-infected patients and to identify factors associated with outbreaks during 20-week follow-up, a randomized, double-blind, placebo-controlled clinical trial was conducted. Subjects were 128 HIV-infected men (aged 27-60 years) who either had had no documented episode of oral candidiasis in the previous year or had been clinically clear of oral candidiasis for at least 72 h before randomization. Study arms were two placebo pastilles, one nystatin (200,000 U) and one placebo pastille, or two nystatin pastilles daily for 20 weeks. The main outcome measure was time to oral candidiasis, as determined by potassium hydroxide (KOH) smear and fungal culture. A multivariate proportional hazards model showed that four factors were significant (p < 0.001) in predicting time to oral candidiasis: nystatin treatment (hazard ratio 0.59), history of oral candidiasis (3.58), Candida albicans carriage (2.79), and CD4 count at randomization (0.65). In this small group of subjects, nystatin appeared to be effective in delaying onset of oral candidiasis. Patients with CD4 counts < 200 who are carriers of C. albicans and have a history of oral candidiasis may be most likely to benefit from antifungal prophylaxis.

Recurrent aphthous ulcers in association with HIV infection. Description of ulcer types and analysis of T-lymphocyte subsets.

This study was conducted to characterize the recurrent aphthous ulcers (RAU) found in association with human immunodeficiency virus (HIV) infection, to examine evidence for increased severity of the ulcers with HIV disease, and to determine whether increased severity is associated with abnormalities of peripheral blood lymphocyte subsets. Seventy-five HIV-seropositive patients with RAU were followed for up to 2 years, and lymphocyte subsets were analyzed in 42. Minor, herpetiform, and major ulcer types were seen, but unexpectedly, 66% of the patients had the usually uncommon herpetiform and major types. These types were temporally associated with symptomatic HIV disease. Patients with major RAU were significantly more immunosuppressed than those with minor or herpetiform RAU in that they had fewer CD4 and CD8 lymphocytes (p less than 0.05). The lesion of RAU is considered to represent a local breakdown in immunoregulation. The systemic immune imbalance seen with HIV disease may amplify the local defect and lead to more severe ulcers.

Oral Geotrichum candidum infection associated with HIV infection. A case report.

Infections with Geotrichum species, although rare, are sometimes seen in immunocompromised hosts. We report a case of oral geotrichosis in a patient seropositive for human immunodeficiency virus who had erythematous mandibular and maxillary gingiva but was otherwise free of any active systemic disease. Geotrichum candidum was shown by both culture and histopathology to be present in the lesion and was deduced to be the causative organism. The patient responded well to several weeks of treatment involving oral topical administration of nystatin vaginal tablets.

HPV-associated epithelial atypia in oral warts in HIV+ patients.

Reported are oral mucosal warts (HPV common antigen-positive) from 7 adult HIV+ patients in which there was cytologic atypia and disordered growth. Lesions were papillary, white to red in color, and were located on the lip, gingiva, palate, tongue, and buccal mucosa. Histologically, the keratinocytes in the lesions exhibited atypical features in the form of hyperchromatism and karyomegaly. Koilocytes were frequently seen in the upper level keratinocytes where HPV common antigen was identified. The dysplastic areas, which ranged from mild to severe, typically showed abrupt limiting margins. All lesions exhibited intense PCNA reactivity from basement membrane to surface. Nuclei of mid-level and basal keratinocytes of 3 specimens stained positively for p53 protein. We believe that the atypia found in these lesions represents cytologic change that has malignant potential. The subtype of the HPV in these lesions has not yet been determined.

Effect of highly active antiretroviral therapy on frequency of oral warts.

To investigate changes in the pattern of oral disease associated with highly active antiretroviral therapy (HAART), we assessed the frequency of these lesions in our clinic over 9 years. We retrospectively studied 1280 patients seen between July, 1990, and June, 1999, and related oral findings to medication use, immune function, and viral load. We found significant decreases in oral candidosis, hairy leucoplakia, and Kaposi's sarcoma over time, but no change in the occurrence of aphthous ulcers. There was an increase in salivary-gland disease and a striking increase in warts: three-fold for patients on antiretroviral therapy and six-fold for those on HAART (p=0.01). This pattern of oral disease in a referral clinic suggests that an increase in oral warts could be occurring as a complication of HAART.

Concurrent oral cytomegalovirus and herpes simplex virus infection in association with HIV infection. A case report.

Recurrent oral herpes simplex virus lesions are common in both immunocompetent and immunocompromised persons. In contrast, cytomegalovirus-associated intraoral lesions are rarely seen, even in the immunocompromised host. We report a case of concurrent oral herpes simplex virus and cytomegalovirus infection, appearing as an ulcerative lesion of the labial mucosa in a patient with acquired immunodeficiency syndrome. Herpes simplex virus type 1 was shown to be present in the lesion by culture tests, histopathologic examination, immunohistochemistry findings and a direct immunofluorescence assay, and cytomegalovirus by histopathologic examination and immunohistochemistry findings. We deduce that the lesion was due to concurrent herpes simplex virus-1 and cytomegalovirus infection. The patient responded well to 2 weeks of treatment with a high dose of acyclovir.