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Biomedical subjects

M J Hicks

Publications and source records attributed to M J Hicks.

At least 55 records · Page 3Linked to original sources

Infectious susceptibility and severe deficiency of leukocyte rolling and recruitment in E-selectin and P-selectin double mutant mice.

During the initial phase of the inflammatory response, leukocytes marginate and roll along the endothelial surface, a process mediated largely by the selectins and their ligands. Mice with mutations in individual selectins show no spontaneous disease and have mild or negligible deficiencies of inflammatory responses. In contrast, we find that mice with null mutations in both endothelial selectins (P and E) develop a phenotype of leukocyte adhesion deficiency characterized by mucocutaneous infections, plasma cell proliferation, hypergammaglobulinemia, severe deficiencies of leukocyte rolling in cremaster venules with or without addition of TNF-alpha, and an absence of neutrophil emigration at 4 h in response to intraperitoneal Streptococcus pneumoniae peritonitis. These mice provide strong evidence for the functional importance of selectins in vivo.

Animals↗

Congenital heterotopic gastrointestinal cyst of the oral cavity in a neonate: case report and review of literature.

Heterotopic gastrointestinal cysts of the oral cavity are rare benign lesions which may mimic both benign and malignant neoplasms. These cysts are usually discovered during infancy, but may not appear until well into adulthood. This lesion involves the tongue and floor of the mouth in 97% of cases and has a male predilection. The cyst may range in size from less than 1 cm to 9 cm, with most lesions being 1-3 cm in size. About 30% of affected individuals have symptoms related to difficulties with feeding, swallowing and respiration. The epithelial lining is quite variable, but all cysts have an enteric lining. The histogenesis is related to entrapment of undifferentiated, noncommitted endoderm within the oral cavity during the 3rd-4th week of fetal life. The purpose of this paper is to report a congenital heterotopic gastrointestinal cyst of the oral cavity presenting in a neonate. The clinical and histopathologic features of this cyst are reviewed, as well as the histogenesis of this lesion.

Choristoma↗

Herpesviridae-associated persistent mucocutaneous ulcers in acquired immunodeficiency syndrome. A clinicopathologic study.

Persistent mucocutaneous ulcers in AIDS represent a variety of disease entities. The purpose of this study was to characterize clinicopathologic features of persistent oral ulcers associated with cytomegalovirus and herpes simplex virus in AIDS. Forty-seven persons infected with HIV with persistent ulcers (mean, 2.4 ulcers/person) were included in this study. A biopsy specimen from a representative ulcer was taken from each patient. Hematoxylin-eosin, periodic acid-Schiff, cytomegalovirus, and herpes simplex virus immunocytochemical stains were performed on tissue sections. The most common sites of involvement were the buccal/labial mucosa (27%), tongue (25%), and gingiva (18%). Mean ulcer size was 1.8 cm with a mean duration of 5.6 weeks. The ulcerogenic viral agents were cytomegalovirus alone in 53% of cases, cytomegalovirus and herpes simplex virus coinfection in 28% of cases, and herpes simplex virus alone in 19% of cases. Treatment response to ganciclovir with or without topical steroids resulted in lesion resolution in the cytomegalovirus and cytomegalovirus/herpes simplex virus groups; however, recurrence/resistance was relatively high (23%). Herpes simplex virus/cytomegalovirus ulcers responded to oral acyclovir in combination with systemic ganciclovir. Increasing the oral acyclovir dosage resulted in resolution of herpes simplex virus-only ulcers in all but one case. Cytomegalovirus and herpes simplex virus are associated with persistent mucocutaneous ulcers in AIDS. These lesions responded to systemic antiviral therapy but are difficult to differentiate from other ulcerogenic diseases such as aphthous major, necrotizing stomatitis, and ulcerations not otherwise specified without biopsy and histopathologic examination.

AIDS-Related Opportunistic Infections↗

Intraabdominal desmoplastic small round cell tumor presenting as a gastric mural mass with hepatic metastases.

PURPOSE: An atypical case of childhood intraabdominal desmoplastic small round cell tumor (DSRCT) is presented. PATIENT AND METHODS: An 11-year-old boy presented with progressive nausea and vomiting, abdominal pain, hepatomegaly, and an epigastric mass. Computed tomographic scanning as well as findings at gastroscopy and laparotomy revealed a large gastric mural tumor accompanied by multiple large intrahepatic masses. Histopathologic examination of biopsy samples revealed evidence of a polyphenotypic neoplasm diagnostic of DSRCT. RESULTS: Unlike most reported cases of DSRCT, no evidence of peritoneal involvement or ascites was detected. Despite an excellent initial response to multiagent chemotherapy, the patient eventually died of progressive tumor. CONCLUSIONS: Though the radiographic and surgical findings in DSRCT usually suggest a mesenteric, peritoneal, or retroperitoneal site of tumor origin, this case demonstrates that intraabdominal DSRCT can present with a primary visceral lesion without evidence of peritoneal or mesenteric involvement or ascites. Combination chemotherapy using vincristine, doxorubicin, cyclophosphamide, cisplatin, and 5-fluorouracil may be of some benefit to patients with this rare tumor.

Abdominal Neoplasms↗

Bond strength of composite to sound and artificial carious dentin.

PURPOSE: To determine the in vitro bond strength of a composite (Herculite XRV) to sound dentin and artificial carious lesions in dentin. MATERIALS AND METHODS: Buccal and lingual surfaces from extracted human molar teeth were ground to expose sound dentin surfaces. The buccal surface was maintained as sound dentin, while an artificial carious lesion was created in the lingual surface using an acidified gelatin gel. A bonding agent (Optibond) was applied to both buccal and lingual surfaces with and without prior etching with 37.5% phosphoric acid. The composite was applied and debonded under tension after 24 hours in water at 37 degrees C. RESULTS: Both sound dentin (23.1 MPa) and etched sound dentin (22.2 MPa) had similar bond strengths, whereas artificial carious lesions in dentin that had been etched (11.8 MPa) and non-etched dentin lesions (8.8 MPa) had significantly lower bond strengths. Adhesive failures were greatest for dentin lesions (60-95%) and least for sound dentin(40-50%). Etching with phosphoric acid did not improve the bond strength of composite to sound dentin or artificial carious lesions in dentin.

Acid Etching, Dental↗

Surface morphology of sound enamel after argon laser irradiation: an in vitro scanning electron microscopic study.

Argon laser irradiation (ALI) at relatively low fluences (energy densities) enhances the caries resistance of sound enamel. The purpose of this SEM study was to compare the effects of argon laser irradiation at relatively low fluences (11.5 Joules/cm2 and 100 Joules/cm2) on enamel surface morphology. Following a fluoride-free prophylaxis, 12 extracted caries-free human molars were sectioned into tooth quarters. Tooth quarters were treated as follows: 1) Mesiobuccal-ALI at 11.5 J/J/cm2 for 10; 2) Distobuccal-Control; 3) Mesiolingual-ALI at 100 J/J/cm2 for 10; and 4) Distolingual-Control. Enamel surface morphology was compared among the two argon laser irradiation groups and matched non-treated control enamel surfaces by SEM. Argon laser treatment resulted in considerable alterations in the surface morphology compared with matched controls. Control enamel surfaces showed relatively smooth contours with occasional termination of enamel prisms at the surface. Both argon laser treatment groups had intact enamel surfaces lacking prism end markings and cratering of the enamel surface. A discontinuous granular surface permeated by numerous microporosities of < 1.0 micron in diameter was created with both argon laser treatment groups. Globular deposits of approximately 0.5 to 2 microns in maximum dimension composed the surface coatings. These deposits were admixed with areas of fine microporosities. Argon laser irradiation at relatively low fluences produces surface coatings which may act as reservoirs for mineral phases during an acidogenic attach of the enamel and may provide a certain degree of protection against a cariogenic challenge.

Argon↗

Role of intralesional vinblastine administration in treatment of intraoral Kaposi's sarcoma in AIDS.

The purpose of this clinical study was to determine the effect of intralesional vinblastine administration on intraoral Kaposi's sarcoma (KS) in AIDS patients. One hundred and forty-four KS lesions in 50 HIV-positive homosexual males (mean CD4 count 64/mm3) were treated periodically with intralesional vinblastine injection (0.1 mg/cm2) until lesion resolution or no further reduction in lesional area. The most common lesion sites were: palate 56% (hard palate 42%, soft palate 14%); gingiva 22% (maxillary 15%, mandibular 7%); and maxillary tuberosity 6%. The mean lesion area was 4.6 cm2 (range = 0.1-35 cm2). Complete resolution occurred in 74%. The mean reduction in lesional area was 93% for all lesions. Lesions with only a partial response (26%) to vinblastine had a mean reduction in the lesional area of 69%. The mean number of treatments was 2.4 (range = 1-6). The recurrence rate was 26% with a mean disease-free period of 12.9 weeks. Recurrence rates were highest for nodular (40%) and purple macular lesions with focal nodularity (36%). The most frequent complications were transient pain (72%), superficial mucosal ulceration (22%) and transient paresthesia (12%). Intralesional vinblastine administration produced complete resolution in a substantial number of intraoral KS lesions and represents a well-tolerated treatment regimen for localised control of intraoral KS lesions. Owing to a 25% recurrence rate, re-evaluation is necessary for treatment of recurrent and new Kaposi's sarcoma lesions.

Acquired Immunodeficiency Syndrome↗

Intraoral squamous cell carcinoma in human immunodeficiency virus infection. A clinicopathologic study.

The purpose of this study was to characterize the clinical and histological features of intraoral squamous cell carcinoma in men who were seropositive for the human immunodeficiency virus and to evaluate viral cofactors (human papillomavirus, herpes simplex virus, Epstein-Barr virus), proliferative index (proliferating cell nuclear antigen), a factor associated with invasion (cathepsin D), and mutated tumor suppressor gene and proto-oncogene products (mutated p53, c-erbB-2). Four men who were seropositive for the human immunodeficiency virus and had acquired immunodeficiency syndrome presented with painful oral lesions of variable duration. Oral cancer risk factors included heavy tobacco use (four of four), heavy alcohol use (three of four), and previous radiotherapy (one of four). The lesions consisted of ulcers (two of four), a fungating mass (one of four), and papillary erythroplakia (one of four). Incisional biopsy specimens were obtained. High-stringency in situ hybridization was performed with DNA probes to the human papillomavirus (types 6/11; 16/18; 31/33/35) and Epstein-Barr virus: Immunocytochemical studies for the herpes simplex virus, proliferating cell nuclear antigen, cathepsin D, mutated p53, and c-erbB-2 were performed. Two lesions were moderately differentiated squamous cell carcinoma, one lesion was a basaloid squamous cell carcinoma, and one was carcinoma in situ. Stage of disease at diagnosis was II (one of four), III (two of four), and IV (one of four). Three cases were positive for the human papillomavirus, one case was positive for Epstein-Barr virus, and three cases were positive for the herpes simplex virus. C-erbB-2 was focally positive in one case, and mutated p53 was positive in a separate case.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effects of argon laser irradiation and acidulated phosphate fluoride on root caries.

PURPOSE: To determine the effects of argon laser irradiation (ArI) and topical acidulated phosphate fluoride (APF) treatment on artificial caries formation in root surfaces. MATERIALS AND METHODS: After soft tissue debridement and fluoride-free prophylaxis, the teeth were divided into quarters and acid-resistant varnish was applied, leaving windows of sound root surface exposed. Each tooth received four separate treatments: (1) Control-mesiobuccal quarter; (2) ArI only--mesiolingual quarter; (3) ArI followed by APF- distobuccal quarter; (4) APF followed by ArI-distolingual quarter. ArI was for 10 seconds at 2W (100J/cm2) and APF treatment was for 4 minutes. After artificial lesion formation, sections were prepared and evaluated with polarized light. Mean lesion depths were determined and compared (ANOVA & DMR for a paired design). RESULTS: Mean lesion depths were: 347 +/- 41 microns--controls; 263 +/- 32 microns--ArI only; 158 +/- 21 microns--ArI followed by APF; and 149 +/- 17 microns -APF followed by ArI. Lesion depths were significantly different (P < 0.05) between the control group and each treatment group, and between ArI only group and either combined APF and ArI groups. No lesion depth difference (P > 0.05) was present between the combined APF and ArI groups. Argon laser irradiation significantly enhanced the resistance of root surfaces to demineralization. Combination of APF treatment with argon laser irradiation provided added protection against a constant artificial caries attack.

Acidulated Phosphate Fluoride↗

Acidulated phosphate fluoride treatment and formation of caries-like lesions in enamel: effect of application time.

The aim of this study was to evaluate the effect of acidulated phosphate fluoride (APF) application time (1 and 4 minutes) on caries-like lesion formation in enamel. Following a fluoride-free prophylaxis, the specimens (10 extracted human molars) were divided into tooth quarters and assigned to treatment groups: 1) Distobuccal and Distolingual Quarters--1 minute APF; 2) Mesiobuccal and Mesiolingual Quarters--4 minute APF. Acid-resistant varnish was applied to the tooth quarters, leaving sound enamel windows exposed on buccal and lingual surfaces. Following treatment, the APF gel (Oral-B Minute Gel) was removed by air-water spray rinsing, followed by a 24-hour water rinse. Sound enamel windows protected from APF treatment by acid-resistant varnish were created adjacent to APF-treated sound enamel windows and served as paired controls. Lesions were created in APF-treated and paired control sound enamel windows with an acidified gel. After lesion formation, sections were obtained and imbibed with water for polarized light study. Body of the lesion depths were measured and compared statistically. Mean body of the lesion depths were: 186 +/- 28 microns for control lesions, 117 +/- 12 microns for APF-1min; and 111 +/- 14 microns for APF-4min. Significant differences (p < 0.05) were found between paired control and APF groups. No difference (p > 0.05) was found between APF-1min and APF-4min groups. APF treatment prior to lesion formation resulted in a significant reduction in lesion depth, regardless of whether a 1 or 4 minute APF treatment period was used. The 1 minute APF treatment provided the same degree of caries protection as the longer treatment period.

Acidulated Phosphate Fluoride↗

An overview of the oral manifestations of AIDS-related Kaposi's sarcoma.

Acquired immunodeficiency syndrome-associated Kaposi's sarcoma (AIDS-KS) is the most common malignancy in human immunodeficiency virus infection and is seen most often in homosexual men. The oral cavity is frequently involved by AIDS-KS and may represent the initial site of this malignancy in up to 60% of patients. A number of treatment modalities, including systemic and localized chemotherapy and radiotherapy, are available for AIDS-KS. The initial diagnosis of AIDS-KS requires microscopic evaluation of biopsy material because this disease can mimic a number of intraoral lesions, including atrophic candidiasis, erythroplakia, pyogenic granuloma, bacillary angiomatosis, median rhomboid glossitis, hemangioma, and lymphoma. Overall, treatment of AIDS-KS does not significantly affect the prognosis or survival of AIDS patients, however, treatment can alleviate aerodigestive and/or respiratory dysfunction, allow for adequate nutritional intake, and improve the quality of life for these patients.

Acquired Immunodeficiency Syndrome↗

Enamel caries initiation and progression following low fluence (energy) argon laser and fluoride treatment.

The aim of this study was to evaluate the effect of low fluence argon laser (AL) and acidulated phosphate fluoride (APF) treatment on caries initiation (CI) and progression (CP) in human enamel. Twenty caries-free molars were divided into tooth quarters. Tooth quarters from each specimen were assigned to one of four groups: 1) Control; 2) AL Only; 3) AL before APF; 4) APF before AL. AL was at 0.25 watts for 10 seconds (12.0 +/- 0.5 J/cm2). APF treatment was with a 1.23% gel for 4 minutes. Lesions were created in two treated, sound enamel windows per tooth quarter with an acidified gel. After CI and CP, sections were obtained and imbibed with water for polarized light study. Mean body of the lesion (BL) depths were determined and compared among groups (ANOVA & DMR). After CI, BL depths were: 189 +/- 29 micrometers for Control, 133 +/- 23 micrometers for AL only; 91 +/- 17 micrometers for AL before APF; and 83 +/- 14 micrometers for APF before AL. After CP, BL depths were: 321 +/- 43 micrometers for Control, 206 +/- 35 micrometers for AL only; 118 +/- 21 micrometers for AL before APF; and 114 +/- 19 micrometers for APF before AL. After CI and CP, argon laser irradiation alone resulted in significant reductions in lesion depth when compared with controls (p<0.05). APF treatment before or after argon laser exposure resulted in a significant reduction in lesion depth when compared with AL alone or control groups (p<0.05). Caries initiation and progression in vitro are affected to a significant extent when low fluence (energy) argon laser irradiation of sound enamel alone or in conjunction with APF treatment is done. This caries-protective effect occurs at an argon laser fluence (energy) that is capable of polymerizing visible light-cured resins.

Acidulated Phosphate Fluoride↗

Prognostic factors in mucoepidermoid carcinomas of major salivary glands: a clinicopathologic and flow cytometric study.

Mucoepidermoid carcinomas (MEC) of the major salivary glands from 48 patients who received their treatment at a single institution were studied for prognostic indicators. Uni- and multivariate statistical analyses were performed on several clinicopathologic factors and also on flow cytometric (FCM) DNA content data of the carcinomas. Clinical prognostic factors associated with decreased survival included age > 60 years (P = 0.01), male gender (P = 0.002), symptoms at diagnosis (P = 0.03), stage of disease (P < or = 0.0001), type of surgery (P = 0.0006), and recurrence (P = 0.0001). Histopathological prognostic factors associated with decreased survival included MEC tumour grade (P = 0.0001), tumour size > 3.0 cm (P = 0.02), lymph node involvement (P = 0.0004) and positive surgical margins (P = 0.007). DNA FCM factors associated with decreased survival included aneuploid tumours (P = 0.08) and proliferative activity (S+G2M > 5%, P = 0.07). Multivariate analysis indicated that histological grade, proliferative activity, symptoms at diagnosis, clinical stage of disease and type of surgery were significant (P < or = 0.05) prognostic/survival factors in the biological assessment of this neoplasm.

Adolescent↗

Intracoccygeal and pericoccygeal glomus bodies and their relationship to coccygodynia.

BACKGROUND: Coccygodynia is an uncommon condition of diverse causes. A few cases were attributed to so-called pericoccygeal glomus tumors. However, the pericoccygeal soft tissues normally contain numerous small glomus bodies and a larger one known as the glomus coccygeum, which can reach several millimeters in diameter. Most reported cases of alleged pericoccygeal glomus tumors represent normal, incidentally discovered coccygeal glomus bodies. Recently, an intracoccygeal glomus tumor was reported as a cause of coccygodynia. However, we suspected that glomera can also occur normally within the coccyx itself. METHODS: Twenty coccyges from fetuses, newborns, infants, and adults were obtained at autopsy, embedded in toto, and examined histologically in step sections. RESULTS: Intracoccygeal glomera were present in six of the nine pediatric specimens and all 11 adult specimens. All were microscopic structures, and none appeared to have caused bony destruction or erosion. They did not differ from the structures previously reported as alleged intracoccygeal "glomus tumors." CONCLUSIONS: Pericoccygeal and intracoccygeal glomus bodies are normal findings in humans at all ages. They should not be mistaken for tumors, and their role in the pathogenesis of coccygodynia is questionable.

Adult↗