A new C-Peptide correction model used to assess bioavailability of regular human insulin

The clinical assessment of new formulations of human insulin is problematic due to the inability to distinguish between endogenous insulin and exogenously administered insulin. The usual methods to surmount the problem of distinguishing between endogenous and exogenous human insulin include evaluation in subjects with no or little endogenous insulin, hyper-insulinemic clamp studies or the administration of somatostatin to suppress endogenous insulin secretion. All of these methods have significant drawbacks. This paper describes a method for C-Peptide correction based upon a mixed effects linear regression of multiple time point sampling of C-Peptide and insulin. This model was able to describe each individual's insulin to C-Peptide relationship using the data from four different phase I clinical trials involving both subjects with and without type 2 diabetes in which insulin and C-Peptide were measured. These studies used hyper-insulinemic euglycemic clamps or meal challenges and subjects received insulin or Glucagon-like peptide 1 (GLP-1). It was possible to determine the exogenously administered insulin concentration from the measured total insulin concentration. A simple statistical technique can be used to determine each individual's insulin to C-Peptide relationship to estimate exogenous and endogenous insulin following the administration of regular human insulin. This technique will simplify the assessment of new formulations of human insulin.

Oral heparin administration with a novel drug delivery agent (SNAC) in healthy volunteers and patients undergoing elective total hip arthroplasty

BACKGROUND

Unfractionated heparin (UFH) is safe and effective for thromboprophylaxis, but its use is limited to parenteral administration. A novel drug delivery agent (SNAC) has been developed to accomplish the oral delivery of heparin.

OBJECTIVE

This report describes the foundation for dose selection and use of oral heparin/SNAC in patients undergoing elective total hip arthroplasty (THA).

PATIENTS AND METHODS

To develop a treatment regimen for clinical study, a multiple dose Phase I pharmacokinetic (PK) study in healthy volunteers compared oral heparin/SNAC (90 000 U heparin) with subcutaneous UFH (5000 U). On this basis, we carried out a double-blind, randomized, multicenter study comparing subcutaneous UFH (5000 U) with oral heparin/SNAC at either 60 000 or 90 000 U heparin in 123 patients undergoing elective THA. Patients received, postoperatively, one of the three treatments every 8 h for a total of 12 doses and were followed for 35 days post surgery.

RESULTS

In the Phase I study, anti-factor Xa activity peaked at 45-60 min following oral heparin/SNAC, returning to baseline at 4 h. RESULTS of the randomized trial in THA patients showed that venous thromboembolic events (n = 6), major bleeding events (n = 5) and need for transfusion (n = 23) were distributed evenly among the three treatment groups, UFH and both doses of oral heparin/SNAC.

CONCLUSION

This is the first demonstration that oral heparin/SNAC can be safely delivered to the postoperative THA patient, and provides the basis for a larger clinical trial to assess the prophylactic efficacy of heparin/SNAC.

Aggressive osteoblastoma of the mandible closely simulating calcifying epithelial odontogenic tumor. Report of two cases with unusual histopathologic findings

Aggressive osteoblastoma is a rare bone-forming neoplasm composed of prominent epithelioid cells that demonstrate locally invasive growth with a high rate of recurrence but no metastatic potential. Clinical, radiographic and pathologic features of mandibular aggressive osteoblastoma in a 21-year-old African-American male and a 12-year-old Caucasian female are presented. Both tumors were resected with wide surgical margins and neither patient had adjuvant radiation or chemotherapy. The patients showed no evidence of local recurrence or distant spread either clinically or radiographically after two years of follow-up. These tumors were composed of solid sheets of pleomorphic epithelioid cells, eosinophilic amorphous osteoid with foci of calcification, which closely simulated amyloid. Differentiation of this tumor from histologically similar calcifying epithelial odontogenic tumor and low-grade osteosarcoma proved difficult. Immunohistochemical study with osteocalcin confirmed the osteoblastic nature of these epithelioid cells.

Oral delivery of biologically active parathyroid hormone

PURPOSE

Parathyroid hormone (PTH), the only drug known to stimulate bone formation. is a peptide therapeutic indicated in the treatment of osteoporosis. Unfortunately, PTH is only effective when dosed by injection because it has no oral bioavailability. Herein we report the oral absorption of PTH in rats and monkeys facilitated by the novel delivery agent, N-[8-(2-hydroxy-4-methoxy)bensoyl]amino caprylic acid (4-MOAC).

METHODS

4-MOAC was selected from a group of 100 delivery agents based on in vitro chromotography studies and in vivo screening studies in rats. The PTH/4-MOAC combination was then tested in monkeys. The interaction of 4-MOAC and PTH was evaluated by nuclear magnetic resonance (NMR) spectroscopy.

RESULTS

Monkeys were administered an aqueous solution containing 4-MOAC and PTH and mean peak serum PTH concentrations of about 3000 pg/mL were obtained. The relative bioavailability of oral PTH was 2.1% relative to subcutaneous administration. The biological activity of the orally-delivered PTH was further evaluated in a rat model of osteoporosis. These studies showed that the bone formed following oral PTH/4-MOAC administration was comparable to that formed following PTH injections. The 4-MOAC mediated absorption of PTH is hypothesized to be the result of a noncovalent interaction between 4-MOAC and PTH. The preliminary evaluation of this interaction by NMR is described.

CONCLUSIONS

4-MOAC facilitates the absorption of PTH following oral administration to both rats and monkeys. The orally-absorbed PTH is biologically active as demonstrated in a rat model of osteoporosis.

Studies directed at the use of a parallel synthesis matrix to increase throughput in an in vivo assay

Heparin is the anticoagulant of choice for hospitalized patients, but it is dosed only by injection because it is not absorbed following oral administration. We have discovered and prepared compounds (delivery agents) that facilitate the gastrointestinal absorption of heparin in rats, monkeys, and humans when given orally. We are currently developing a parallel synthesis approach to increase our delivery agent screening throughput in vivo. This approach has been used to produce micromolar quantities of compounds for testing in rats in a 5 x 5 parallel synthesis array. Using an amine benzoylation reaction sequence, 10 mixtures were prepared. These mixtures contained equal weight quantities of five N-substituted, non-alpha, amino acid delivery agents. Each of these mixtures was orally administered to rats in combination with heparin, and plasma clotting times (APTT) were measured to determine activity. Deconvolution of the data accurately identified the most active individual components. Independent synthesis of these compounds verified their activity. This parallel synthesis approach is an effective tool for the screening of oral heparin delivery agents and has increased screening throughput significantly.

Orally administered unfractionated heparin with carrier agent is therapeutic for deep venous thrombosis

BACKGROUND

Orally administered heparin (OHEP) is unreliable because of poor absorption. Sodium N-(8[2-hydroxybenzoyl]amino) caprylate (SNAC) is an amido acid that facilitates the gastrointestinal absorption of heparin. We evaluated the effectiveness of OHEP combined with SNAC (OHEP/SNAC) in the treatment of deep-vein thrombosis (DVT).

METHODS AND RESULTS

An internal jugular DVT was produced in 54 male Sprague-Dawley rats. Animals were assigned to 6 different groups for 7 days of treatment: untreated control, subcutaneous heparin (SC HEP) (300 U/kg SC TID), SNAC only (300 mg/kg PO TID), OHEP only (30 mg/kg PO TID), low-molecular-weight heparin (LMWH) (enoxaparin 5 mg/kg SC QD), and OHEP/SNAC (30 mg/kg:300 mg/kg PO TID). The activated partial thromboplastin time (aPTT) and anti-factor X (anti-Xa) levels were measured. The incidence of residual DVT after 1 week of treatment was 100% (9 of 9) in the control group versus 10% (1 of 10) in the OHEP/SNAC and 10% (1 of 10) in the LMWH groups (P<0.001). There was also a significant reduction in clot weights between these groups. Compared with controls, there were no significant differences in the residual DVT in the SNAC-only (6 of 6), OHEP-only (9 of 9), or SC HEP (8 of 10) groups. Combination OHEP/SNAC was as effective in the resolution of the clot and reducing clot weight as LMWH. The aPTT levels in the OHEP/SNAC group peaked at 30 minutes and were significantly higher than in all other groups (P<0.01). Anti-Xa levels were elevated at 15 minutes after dosing in the OHEP/SNAC group and remained significantly elevated at 4 hours (P<0.001).

CONCLUSIONS

OHEP combined with a novel carrier agent (SNAC) successfully treated DVT in this rat model.

Oral delivery of anticoagulant doses of heparin. A randomized, double-blind, controlled study in humans

BACKGROUND

Parenteral heparin is the anticoagulant of choice in hospitalized patients. Continued anticoagulation is achieved by subcutaneous administration of low-molecular-weight heparin or with an orally active anticoagulant such as warfarin. An oral heparin formulation would avoid the inconvenience of subcutaneous injection and the unfavorable drug interactions and adverse events associated with warfarin. A candidate delivery agent, sodium N-[8(-2-hydroxybenzoyl)amino]caprylate (SNAC), was evaluated with escalating oral heparin doses in a randomized, double-blind, controlled clinical study for safety, tolerability, and effects on indexes of anticoagulation.

METHODS AND RESULTS

Increases in activated partial thromboplastin time (aPTT), anti-factors IIa and Xa, and tissue factor pathway inhibitor (TFPI) concentrations were detected when normal volunteers were dosed with 10.5 g SNAC/20000 IU heparin by gavage in some subjects. For the entire group, 30000 IU SNAC and heparin elevated TFPI from 74.9+/-7.6 to 254.2+/-12.3 mg/mL (P<0.001) 1 hour after dosing (P<0.001). Similar changes occurred in anti-factor IIa and anti-factor Xa. aPTT rose from 28+/-0.5 to 42.2+/-6.3 seconds 2 hours after dosing (P<0.01). No significant changes in vital signs, physical examination, ECGs, or clinical laboratory values were observed. Neither 30000 IU heparin alone nor 10.5 g SNAC alone altered the hemostatic parameters. Emesis was associated with 10.5 g SNAC. A taste-masked preparation of SNAC 2.25 g was administered orally with heparin 30000 to 150000 IU. Both aPTT and anti-factor Xa increased with escalating doses of heparin. This preparation was well tolerated. Conclusions-Heparin, administered orally in combination with the delivery agent SNAC, produces significant elevations in 4 indexes of anticoagulant effect in healthy human volunteers. These results establish the feasibility of oral delivery of anticoagulant doses of heparin in humans and may have broader implications for the absorption of macromolecules.

Orally administered heparin for preventing deep venous thrombosis

BACKGROUND

Sodium N-(8-[2-hydroxybenzoyl] amino) caprylate (SNAC) is an acetylated amino acid molecule that facilitates the gastrointestinal absorption of heparin. This study was undertaken to evaluate the efficacy of orally administered combination SNAC:heparin in preventing deep venous thrombosis in a standard rat model.

METHODS

Forty-four adult male Sprague-Dawley rats were randomly divided into five groups: group I control, group II SNAC, group III oral heparin, group IV combination SNAC:heparin, and group V intravenous heparin. Thirty minutes after drug administration, the internal jugular vein was bathed in a sclerosant mixture for 2 minutes and reexplored at 120 minutes. Activated partial thromboplastin times (aPTT) were measured in 30 rats equally divided into three groups: group I SNAC, group II oral heparin, and group III combination SNAC:heparin. Forty-five minutes posttreatment, blood was obtained for aPTT levels.

RESULTS

The incidence of deep venous thrombosis in the control group was 89% (8 of 9) versus 25% (2 of 8) in the combination SNAC:heparin group (p < 0.01). There was also a significant reduction in clot weight among groups. Combination SNAC:heparin significantly increased aPTT levels compared with SNAC or oral heparin alone.

CONCLUSION

In a rat model of venous thrombosis, combination of orally administered heparin:SNAC elevated aPTT levels and significantly reduced the formation of deep venous thrombosis.

Synthesis and evaluation of compounds that facilitate the gastrointestinal absorption of heparin

A family of novel compounds (delivery agents) that promote the gastrointestinal absorption of USP heparin in rats and primates has been discovered. The delivery agents in combination with heparin were administered either orally or intracolonically in an aqueous propylene glycol solution and caused dramatic increases in both plasma heparin concentrations (anti-Factor Xa) and clotting times (APTT). Using one of the most effective delivery agents in this series, an estimated relative bioavailability of 8% can be achieved following oral administration to cynomolgus monkeys. To establish a correlation between the in vivo data and an in vitro parameter, immobilized artificial membrane (IAM) chromatography was performed. Log relative k' values were correlated to the efficiency of oral heparin delivery.

Recurrent aphthous stomatitis vs. recurrent herpes: do you know the difference?

Herpetic and aphthous ulcers can be easily separated from each other on a clinical basis. Most patients who suffer from recurrent oral ulcers, suffer from one of the three forms of aphthous stomatitis that can be effectively treated. Unfortunately, the dental and medical professions are uninformed about recurrent oral ulcer etiology and proper therapies. The result is that large numbers of patients are repeatedly told there is no adequate treatment or control for their condition when in most cases that is not true. We should not permit that trend to continue. Our patients deserve better treatment from a more informed profession.

Acylated non-alpha-amino acids as novel agents for the oral delivery of heparin sodium, USP

Ten N-acylated, non-alpha-amino acids have been prepared as oral delivery agents and used to demonstrate the oral delivery of heparin in vivo in rats and primates. Following the oral administration of solutions containing a combination of heparin and a delivery agent to rats or primates, significant plasma heparin concentrations were evidenced by APTT and anti-Factor Xa assays. The estimated pharmacodynamic equivalence for an oral dosing solution containing heparin and a delivery agent is 39% in primates. In vitro experiments based on heparin affinity chromatography or heparin/methylene blue complexation were also performed to begin investigation of the mechanism by which these compounds facilitate heparin oral delivery. Results of in vitro studies suggest that absorption of the drug across the gastrointestinal membrane is the result of a non-covalent interaction between heparin and the delivery agent.

Vascular leiomyoma of the superior turbinate: first reported case

BACKGROUND

Vascular leiomyoma is an uncommon smooth muscle tumor rarely found in the head and neck area. We report the first case arising for the superior turbinate of the nasal cavity.

METHODS

A case presentation, treatment, and review of the literature are discussed.

RESULTS

Twenty-one months after embolization and surgical resection, the patient is doing well, without evidence or recurrence.

CONCLUSIONS

Vascular leiomyoma is a rare benign tumor of the nasal cavity, and surgical excision yields high cure rates.

4-[4-[(2-Hydroxybenzoyl)amino]phenyl]butyric acid as a novel oral delivery agent for recombinant human growth hormone

A series of N-acetylated, non-alpha, aromatic amino acids was prepared and shown to promote the absorption of recombinant human growth hormone (rhGH) from the gastrointestinal tract. Seventy compounds in this family were tested in vivo in rats. Of the compounds tested, 4-[4-[(2-hydroxybenzoyl)amino]phenyl]butyric acid was identified as a preclinical candidate and was used to demonstrate the oral delivery of rhGH in primates. A significant positive correlation was found between the relative log k' of the delivery agents, as determined by HPLC on an immobilized artificial membrane (IAM) column, and serum rhGH concentrations following oral or colonic dosing in rats. Structure-activity relationships have also been developed on the basis of electronic effects and hydrogen-bonding characteristics of the aromatic amide substituents.

Recurrent aphthous stomatitis: primary care management

Recurrent aphthous stomatitis (RAS), often referred to as canker sore, is a chronic inflammatory disease. Frequently seen in the primary care setting, RAS affects over 50% of the population and may be observed in an otherwise apparently healthy individual. An unknown pathogenesis and absence of curative treatment make RAS a challenge to manage. Treating RAS should be patient specific and focus on reduction of pain and lesions. An awareness of literature suggesting etiologies, precipitating, and predisposing factors can assist the practitioner and patient in controlling RAS episodes. Contained in this review is a suggested course of management for patients with RAS, including present recommendations for pharmacological interventions.

Oral delivery of sodium cromolyn: preliminary studies in vivo and in vitro

PURPOSE

Herein we report the discovery of a group of derivatized alpha-amino acids that increase the oral bioavailability of sodium cromolyn.

METHODS

We prepared three N-acylated alpha-amino acids and used these compounds to demonstrate the oral delivery of cromolyn in an in vivo rat model. In vitro experiments, including permeation studies and near infrared spectroscopy, were also performed to initiate an understanding of the mechanism by which these compounds facilitate cromolyn oral delivery.

RESULTS

Following oral administration to rats of solutions containing a combination of cromolyn and the delivery agent, significant systemic plasma concentrations of the drug were detected. In vitro studies suggest that absorption of the drug across the gastrointestinal membrane is a passive process.

CONCLUSION

The absolute oral bioavailability of sodium cromolyn in the rat model is estimated to be approximately 5%. Preliminary mechanistic studies suggest that a complex of the cromolyn/delivery agent facilitates permeation across/through the membrane.

Systemic mastocytosis involving the mandible

Systemic mastocytosis is a rare and clinically fascinating disorder that usually involves the skin and hematopoietic tissues. We report a patient with systemic mastocytosis involving the mandible who had no other presenting bone lesions on scintigraphic exam. After noting the radiographic emergence of this osteolytic jaw lesion over a 6-month interval, a biopsy of the lesion was performed, and histologic and electron microscopic studies completed. It is believed that this is the first documented case of mastocytosis to involve an oral-maxillofacial bone. Careful preoperative evaluation and clinical management were conducted to avoid potentially life-threatening complications. A discussion of this condition and strategies for diagnosis and patient management are presented.

The Cytobrush Plus cell collector in oral cytology

The Cytobrush Plus cell collector (cytobrush) was compared with the wooden tongue depressor during oral exfoliative cytology. The degree of patient discomfort, the convenience to the clinician, and the quantity and distribution of epithelial cells collected were evaluated. Two-factor analysis of variance and parametric and nonparametric analyses were performed. Because of the favorable findings revealed in this study, we recommend that the cytobrush be considered for use when obtaining diagnostic cytologic smears from the oral mucosa.

Stability study of drug-loaded proteinoid microsphere formulations during freeze-drying

Drug-loaded proteinoid microspheres were freeze-dried to facilitate shipping and handling and to enable long term storage. Heparin was chosen as the model drug in developing the optimum lyophilization process. The factors influencing the integrity of either heparin-loaded or unloaded ('empty') proteinoid microspheres during freeze-drying were determined, with emphasis on: selecting an optimum freezing and resuspending temperature; choosing an appropriate cryoprotectant and its optimum concentration in the formulation; and, designing a suitable method for formulating the microspheres. Freezing at/below -70 degrees C was found to minimize damage to the microspheres. Addition of sugars, such as trehalose and lactose, as cryoprotectants, further increased the stability of the heparin-loaded microspheres during freeze-drying. The optimum trehalose or lactose concentrations were determined to be 5% (w/v). Using the optimumized lyophilization process described in this manuscript, microspheres remained intact during freeze-drying. The freeze-dried microspheres were stable for at least three months post-lyophilization.

Eosinophilic granuloma of the mandibular condyle. A case report and management discussion

The occurrence of eosinophilic granuloma in the mandibular condyle has been reported in only three cases. An additional case of eosinophilic granuloma of the mandibular condyle is reported. The lesion presented was treated with condylectomy and surgical curettage. There was no recurrence or soft tissue involvement on annual postoperative examination. Secondary reconstruction was planned but was not required.

Multiple idiopathic mandibular bone cysts in a patient with osteogenesis imperfecta

Although the most common oral manifestation of osteogenesis imperfecta is dentinogenesis imperfecta, several authors have described jaw fractures and radiolucent bone lesions associated with this disease. We report a case of a 23-year-old white woman with osteogenesis imperfecta and dentinogenesis imperfecta who developed multiple unilocular, bilateral, radiolucent lesions of the mandible 5 years after presenting with a condylar fracture. This is the first documentation by surgical and histopathologic examination that the radiolucent lesions in this particular case represent multiple idiopathic bone cysts.

Cytomegalovirus infections of the oral cavity. A report of six cases and review of the literature

Cytomegalovirus is responsible for a significant percentage of asymptomatic viral infections worldwide. Although virtually any cell or organ may be infected, involvement of the oral cavity is uncommon. Only nine well-documented examples of intraoral cytomegalovirus infections were found in a review of the English-language literature. We report six additional examples, five of which possessed unique clinical and histopathologic characteristics. The light and electron-microscopic features of cytomegalovirus are discussed, as well as diagnostic adjuncts such as immunohistochemistry and deoxyribonucleic acid in situ hybridization.

The simultaneous occurrence of oral herpes simplex virus, cytomegalovirus, and histoplasmosis in an HIV-infected patient

Numerous publications have reviewed the oral manifestations of HIV infection and AIDS. Although uncommon, herpetic infections and histoplasmosis are among the diseases reported. The case that follows presents the first description of the simultaneous occurrence of oral herpes simplex virus, cytomegalovirus, and histoplasmosis in an HIV-infected person. These infections appeared as extensive oral ulcerations and were the only clinical manifestation of HIV infection. Eleven months after the initial presentation, the patient died of complications of AIDS.

Oral squamous cell carcinoma in identical twins: report of a case

This case report describes two middle-aged identical female twins with a mild to moderate history of tobacco and alcohol abuse who developed squamous cell carcinomas in the same anatomic sites. By exclusion of major factors, a correlation between heredity and the incidence of cancer in these cases appears likely; however, carcinogenic agents (tobacco and alcohol) must also be considered as contributing factors. Close observation of siblings (and certainly twins) is recommended when head and neck carcinoma occurs prior to middle age. Although no genetic population prone to oral cancer is known, the disease is rare enough in younger individuals to raise the question of a possible genetic predisposition.

Pharmacokinetics of recombinant murine interferon-gamma and human interferon-alpha A/D(Bgl) administered in concert and their influence on natural killer cell function in mice

The pharmacokinetics of recombinant murine interferon-gamma (rMuIFN-gamma) administered alone and in combination with recombinant hybrid human interferon-alpha (rHuIFN-alpha A/D-[Bgl]) were studied following intravenous (i.v.) and intramuscular (i.m.) injections into mice. The concomitant influence of these IFNs on splenic natural killer (NK) cell function was also examined. The coinjection of both IFNs did not affect the pharmacokinetics of either after i.v. administration. However, simultaneous injection of both IFNs i.m. does result in statistically significant changes in the serum concentrations of rHuIFN-alpha A/D(Bgl). The clinical benefits of the increased bioavailability of rHuIFN-alpha A/D(Bgl) are not apparent since NK cell enhancement after both IFNs were injected together was the same as that obtained after injection of rHuIFN-alpha A/D(Bgl) alone. NK cell enhancement after both IFNs were injected together was the same as that obtained after injection of rHuIFN-alpha A/D(Bgl) alone. Correspondingly, the coinjection of both IFNs did not affect the pharmacokinetics of either.

Pharmacokinetics and tissue distribution of recombinant human tumor necrosis factor-alpha in mice

The serum pharmacokinetics and the major organs of accumulation of recombinant human tumor necrosis factor-alpha (rHuTNF) were determined in BDF1 mice after intravenous and intramuscular administration. Serum concentrations of immunoreactive protein were determined by enzyme-linked immunosorbent assay, and radioactivity was quantitated by beta and gamma scintigraphy. The serum pharmacokinetics of labeled and unlabeled rHuTNF were identical when administered by the intravenous route. After intravenous doses of 165 to 320 micrograms/kg, the clearance was 2.9-3.6 ml/hr, the initial volume of distribution was 1.4-1.6 ml (70-80 ml/kg), and the half-life was 18.5-19.2 min. Intramuscular administration of 320 micrograms/kg resulted in a peak serum concentration of 112 ng/ml. The time of the peak concentration was 1 hr, and the bioavailability of the intramuscular dose was 12%. The data suggest that the disposition of this protein may be biexponential. If this is the case, the terminal phase would appear to account for less than 1% of the total AUC. Since serum concentrations in the terminal phase are at the sensitivity limit of the assay, a single half-life is reported. 125I-Labeled and metabolically labeled 3H-rHuTNF were used to examine tissue distribution. After intravenous 125I-rHuTNF administration, the rank order of accumulation of the 125I-radiolabel in the major organs (per cent dose per organ over 1440 min) was: liver greater than kidney greater than lung greater than heart greater than spleen. This rank order of accumulation was confirmed by intravenous 3H-rHuTNF administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Deposition of viprostol (a synthetic PGE2 vasodilator) in the skin following topical administration to laboratory animals

1. Topical application of 14C-viprostol, a synthetic prostaglandin E2 analogue, to laboratory animals resulted in a significant depot of radioactivity in the skin at the application site in all species studied: mouse, rat, guinea pig, rabbit and monkey, with longer residence times in the larger species. 2. The location of the 14C-label in the skin in mice and monkeys was determined by microscopic autoradiography. Evaluation of the autoradiograms show rapid penetration of the drug into the skin via the hair follicles. 3. In mouse distribution of radioactivity was evident in the stratum corneum and down the hair shafts by 30 min. after dosing. By 2 h radioactivity was also observed throughout the viable epidermis; in the dermis only the hair shafts contained significant radioactivity. At 72 h after dose removal, radioactivity was evident only in the hair follicles and hair shaft. 4. In monkey the residence time of radioactivity in the skin was significantly longer than in mouse, but the general distribution pattern was similar in both species. 5. The presence of viprostol in the hair follicles and epidermal layer after topical administration is consistent with its extensive skin metabolism previously reported.

Characterization of the antitumor activities of human tumor necrosis factor-alpha and the comparison with other cytokines: induction of tumor-specific immunity

We have investigated the in vitro and in vivo antitumor activities of recombinant human tumor necrosis factor-alpha (rHuTNF-alpha) against Meth A sarcoma. Meth A sarcoma cells were found to a) be relatively insensitive in vitro to rHuTNF-alpha, and b) express low numbers of TNF-alpha receptors. Intraperitoneally implanted Meth A sarcoma was insensitive to the antitumor effects of rHuTNF-alpha. In contrast, rHuTNF-alpha was highly efficacious against subcutaneously implanted Meth A sarcoma. Biodistribution studies with 125I- or 3H-labeled rHuTNF-alpha demonstrated that, after intravenous administration, the majority of the labeled rHuTNF-alpha localized in the kidney, lungs, and liver. Only low levels of radiolabel were found in subcutaneous Meth A implants. These results support the in vitro data on the low number of TNF-alpha receptors on Meth A sarcoma cells. The ability of rHuTNF-alpha to induce regression of established (7 days) subcutaneous Meth A implants, positively correlated with the degree of both macroscopic and microscopic tumor necrosis. In addition, recombinant human tumor necrosis factor-beta (lymphotoxin) and recombinant murine tumor necrosis factor-alpha induced similar levels of necrosis. Other lymphokines with known antitumor activities, recombinant human interferon-gamma, murine interferon-gamma, and human interleukin 1 alpha, failed to induce detectable necrosis of Meth A sarcoma. Mice which had rejected subcutaneous Meth A sarcoma implants after rHuTNF-alpha treatment and which were later challenged subcutaneously with Meth A sarcoma or other noncross-reacting chemically induced sarcomas were found to be specifically immune to Meth A sarcoma. In addition, low levels of cytotoxic antibodies reactive to Meth A sarcoma were detected in the sera of 21 of 30 Meth A immune mice. Histological evaluation of the hemorrhagic tumor necrosis induced by rHuTNF-alpha suggests that the primary lesion is vascular, possibly directly on the endothelial cells. The mechanisms involved in the generation of specific cell-mediated antitumor immunity in this model are at present unknown.

Characterization of the antitumor activities of human tumor necrosis factor-alpha and the comparison with other cytokines: induction of tumor-specific immunity

We have investigated the in vitro and in vivo antitumor activities of recombinant human tumor necrosis factor-alpha (rHuTNF-alpha) against Meth A sarcoma. Meth A sarcoma cells were found to a) be relatively insensitive in vitro to rHuTNF-alpha, and b) express low numbers of TNF-alpha receptors. Intraperitoneally implanted Meth A sarcoma was insensitive to the antitumor effects of rHuTNF-alpha. In contrast, rHuTNF-alpha was highly efficacious against subcutaneously implanted Meth A sarcoma. Biodistribution studies with 125I- or 3H-labeled rHuTNF-alpha demonstrated that, after intravenous administration, the majority of the labeled rHuTNF-alpha localized in the kidney, lungs, and liver. Only low levels of radiolabel were found in subcutaneous Meth A implants. These results support the in vitro data on the low number of TNF-alpha receptors on Meth A sarcoma cells. The ability of rHuTNF-alpha to induce regression of established (7 days) subcutaneous Meth A implants, positively correlated with the degree of both macroscopic and microscopic tumor necrosis. In addition, recombinant human tumor necrosis factor-beta (lymphotoxin) and recombinant murine tumor necrosis factor-alpha induced similar levels of necrosis. Other lymphokines with known antitumor activities, recombinant human interferon-gamma, murine interferon-gamma, and human interleukin 1 alpha, failed to induce detectable necrosis of Meth A sarcoma. Mice which had rejected subcutaneous Meth A sarcoma implants after rHuTNF-alpha treatment and which were later challenged subcutaneously with Meth A sarcoma or other noncross-reacting chemically induced sarcomas were found to be specifically immune to Meth A sarcoma. In addition, low levels of cytotoxic antibodies reactive to Meth A sarcoma were detected in the sera of 21 of 30 Meth A immune mice. Histological evaluation of the hemorrhagic tumor necrosis induced by rHuTNF-alpha suggests that the primary lesion is vascular, possibly directly on the endothelial cells. The mechanisms involved in the generation of specific cell-mediated antitumor immunity in this model are at present unknown.

Gaucher's disease affecting the mandible

A case of Gaucher's disease affecting the left body of the mandible is presented. Dentists can recognize this uncommon disease through the medical history of the patient, the presence of characteristic Gaucher cells on biopsy of the lesion, and decreased serum levels of the enzyme glucocerebrosidase.

Histologic appearance of the bilaminar zone in internal derangement of the temporomandibular joint

Light microscopy was used to examine twenty-six specimens of bilaminar zone tissue excised during surgery for correction of internal derangement of the temporamandibular joint. Each of the specimens was examined for the presence of inflammation, amount of vascularity, arterial wall thickness, presence of fat, appearance of collagen, and amount of elastin present. Wide variation in the histologic appearance was noted among the specimens, although no significant inflammation was observed in any of them. Some indications that this tissue is undergoing adaptive changes include the presence of thickened arterial walls suggesting a decreased blood flow and the tendency for decreased amounts of elastin to be associated with denser-appearing collagen. There is also a tendency for patients with complete dislocation to exhibit less elastin than those with partial dislocation of the meniscus.

Dose-dependent bioavailability of prazosin in beagle dogs

Prior to the introduction of an intravenous dosage form for use in humans, prazosin pharmacokinetic studies emphasizing clearance, hepatic extraction, and bioavailability were carried out in dogs. Two such canine studies reported significantly different values for the oral bioavailability of prazosin. This study investigated the differences in prazosin oral availability in beagle dogs. Three male animals were administered an intravenous (1 mg/kg) and three different oral doses (15, 5, and 1 mg) with a 7-day washout between study days. The mean predicted bioavailability, based on hepatic clearance and an estimate for liver blood flow, was 74%. The mean absolute bioavailabilities, determined for each dose in each animal by comparing dose-corrected areas under the plasma concentration-time curve, were 82, 27, and 23%. Although good agreement was evident in bioavailability between the 15-mg oral dose and what was predicted, calculated availabilities for the 5-mg and 1-mg oral doses were approximately one-third the predicted value. The results obtained from this study, together with data from the two previous studies, indicate that the bioavailability of prazosin in dogs is dose-dependent. Possible mechanisms for this observation are also presented.

The bioavailability and disposition of tiodazosin levulinate in beagle dogs with a comparison to prazosin hydrochloride

Tiodazosin is a recently developed compound that is currently undergoing investigation for use in hypertension. It is structurally and pharmacologically similar to prazosin, the prototype of the aminoquinazoline class of vasodilators. Lacking an intravenous dosage form for use in human subjects, our study concentrated on the determination of the bioavailability and disposition parameters of tiodazosin in dogs, with a comparison to those parameters for prazosin, obtained from previous work in our laboratory. Tiodazosin was administered to five male beagle dogs at a dose of 1 mg/kg both intravenously and as an oral solution. Plasma and whole blood samples were taken serially over 24 hr and analyzed with a new specific and sensitive HPLC assay. The half-life of tiodazosin was significantly shorter than that of prazosin. The tiodazosin-calculated bioavailability was 3-fold less than predicted, whereas prazosin-calculated bioavailability was the same as predicted. Assumptions necessary to predict the bioavailability of compounds cleared by the hepatic route appear to be incorrect for tiodazosin. Possible mechanisms for the unpredictable low tiodazosin bioavailability in dogs are presented.

A survey of panoramic radiographs for evaluation of normal and pathologic findings

Six thousand seven hundred eighty panoramic radiographs were screened to monitor the incidence of normal and pathologic findings. Three different types of panoramic radiograph were used in this study: Panorex, Orthopantomograph, and Panelipse. Visualization of four different anatomic landmarks was used for a statistical comparison of the diagnostic value of the three films: the temporomandibular joint compartments, the external oblique ridge, the mental foramen, and the mandibular canal. The orthopantomograph was judged to be slightly more reliable in producing radiographs for the visualization of the selected anatomic structures. The most common form of pathosis detected was impacted teeth, seen in 22.3 percent followed by retained roots, which appeared in 12.6 percent of the films. Comparing these survey data with three other major studies suggests that confining the previous radiographic examinations to certain selected groups of people may have distorted the incidence of some pathologic conditions in the population. The panoramic radiograph is still considered a supplement to, not a substitute for, the intraoral radiograph.

The oral hair: an extremely rare phenomenon

A proven case of true hair occurring naturally in the mouth has been reported only once previously. A second case of this rare anomaly is reported here. In this case a single hair was found at the base of the attached gingiva in the mandibular cuspid region of a 45-year old white man.

Altered prazosin pharmacokinetics in congestive heart failure

The pharmacokinetics of prazosin (Minipress) were studied in nine patients with NYHA Class 3 or 4 congestive heart failure and in five healthy controls. After a single 5 mg oral dose, plasma concentrations of prazosin, as reflected in the area under the plasma concentration-time curve (AUC) and prazosin plasma half-life, were approximately double in the patients in comparison to the control group. Reduction in hepatic blood flow, altered gastrointestinal absorption of the drug or diminished intrinsic hepatic metabolic activity in the patient group may have contributed to the observed changes in prazosin disposition. The finding of higher prazosin plasma concentrations in patients with refractory heart failure demonstrates the need for close monitoring of these individuals following administration of the drug in the treatment of chronic congestive heart failure.

Prepubertal oral pemphigus vulgaris

Although rare, oral pemphigus vulgaris must be considered in those patients who have a prolonged history of oral lesions. The fact that chronic oral lesions characteristically precede skin changes in pemphigus emphasizes the importance of this disease to the dental profession. Patients with long-term and recurrent vesiculoulcerative oral lesions should undergo biopsy examination to establish the diagnosis. The dentist and the physician must collaborate to establish an appropriate diagnostic and therapeutic plan for the management of these patients.

Chievitz's organ: a potential pitfall in oral cancer diagnosis

It has been reported that epithelial nests associated with sensory nerve fibers may simulate perineural invasion and pose a potential diagnostic problem for surgical pathologists working on frozen tissue specimens from patients with oral cancer. The epithelial structures are not neoplastic, and no known pathologic condition has been associated with them. They are believed to be those structures described scantily in the English literature as Chievitz's organ. The fact that the epithelial nests lie near the plane of injection for the inferior alveolar nerve should be of special interest to dentists, especially oral surgeons and pathologists. Controversy exists as to the exact nature of Chievitz's organ, but the potential hazard of misdiagnosis exists nonetheless. This study of cadaver and autopsy material reaffirms the existence of the epithelial rests and outlines a simple technique for locating them.

Attenuation of prazosin effect on cardiac output in chronic heart failure

The persistence of the hemodynamic effects of prazosin was studied in 12 patients with chronic congestive heart failure. Multidose evaluation involving five 5-mg doses showed the initial decrease in systemic vascular resistance and increase in cardiac index, stroke work index, and stroke volume index to be transient. Doubling the dose did not restore effect. Modest decreases in pulmonary capillary-wedge and mean arterial pressures persisted throughout the study. In six patients, plasma prazosin concentration measured at times of hemodynamic observations showed the initial hemodynamic effect of prazosin to attenuate upon further administration despite mean plasma concentrations that exceeded those measured after the first dose. In patients with chronic heart failure, resting hemodynamic studies suggest a rapid attenuation of prazosin-mediated hemodynamic effect in the presence of adequate plasma concentration. Recognizing this phenomenon, if long-term prazosin therapy for congestive heart failure is contemplated, we suggest the hemodynamic response in individual patients be monitored.