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C D Rice

Publications and source records attributed to C D Rice.

At least 37 records · Page 2Linked to original sources
PubMed1996

Innate immune function as a bioindicator of pollution stress in fish.

Immunotoxicological studies, based on processing of samples in the field and laboratory, were conducted on fish collected from a stream receiving point-source contaminants near its headwaters. Previous studies in this stream have revealed that cytochrome P4501A activity, liver somatic indices, macrophage aggregates, and parasitic liver lesions are significantly elevated in sunfish with the degree of impact decreasing with distance from the contaminant source. Fish collected from each sampling site were equally divided, One group was sacrificed in the field and the spleen and anterior kidney tissues were removed and placed in buffer on ice. The other group was kept in MS-222 for 2 hr and transported to the laboratory for processing. The spleen and anterior kidney from each fish were then prepared as a single cell suspension and shipped overnight to Mississippi State University. Cells were then evaluated for PMA-stimulated phagocyte oxidative burst and non-specific cytotoxic cell (NCC) activity against K562 tumor targets. Oxidative burst responses were dramatically suppressed in both groups at sampling sites near the headwaters but returned to reference levels further downstream. There were no differences between processing strategies at each station. NCC activities did not follow gradient-response patterns observed with phagocyte oxidative burst data and there were inconsistent differences between processing strategies at each site. These data indicate that simple immune function assays, such as phagocyte oxidative burst responses, can be used as a ancillary bioindicator in fish health monitoring and that immune function in these fish can be reliably assessed even if samples are not immediately processed.

Analysis of Variance↗
PubMed1995

The effects of acute exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on glioma-specific cytotoxic T-cell activity in Fischer 344 rats.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most potent environmental immunomodulating agents identified so far. Historically, mice have been used to model mammalian immunobiology and most of the data gathered on the immunotoxicity of TCDD has been obtained from studies with mice. However, rats have been used more extensively in toxicological research to establish human risk assessment criteria. A need exists, therefore, to develop a database using the rat model in immunotoxicology so that complete animal toxicity studies can be conducted. We have treated female Fischer 344 rats with a single i.p. dose of 0.3, 3.0, or 30.0 micrograms/kg TCDD or corn oil vehicle and examined cytotoxic T-cell (CTL) activities 24 days following treatment. Syngeneic in vivo tumor-specific CTLs were generated that model cell-mediated immune reactions against neoplastically transformed self antigens. RT2, a virally-induced Fischer 344 rat glioma, and D74, a ethylnitrosurea-induced Fischer 344 rat glioma were used as targets. This immunological parameter was compared to body, thymic, and liver weights as well as liver ethoxyresorufin deethylase (EROD) activity on day 24 post-TCDD treatment. The results indicate that Fischer 344 rats are very sensitive to TCDD as indicated by severe thymic atrophy and EROD induction at all three doses. In contrast, CTL activity was only marginally affected by these same doses of TCDD with only a modest suppression noted at the highest dose. These results indicate that the CTL response in rats may not be useful in characterizing the effects of this xenobiotic on immunocompetence in the rat.

Animals↗
PubMed1995

Immunotoxicity in channel catfish, Ictalurus punctatus, following acute exposure to tributyltin.

Tributyltin (TBT) is a trialkylated organotin formulated for use primarily as a biocide for aquatic and agricultural industries. Although macrophages isolated from toadfish (Opsanus tau) are sensitive to exposure, very little is known about the effects of TBT on fish humoral immunity and non-specific cytotoxic cell (NCC) functions. To evaluate the effects of TBT on these parameters, channel catfish (Ictalurus punctatus) were given a single intraperitoneal injection of corn oil with 0 (vehicle control) or with 0.01, 0.1, and 1.0 mgTBT/kg as TBTCl. Three and seven days later, NCC activity and phagocyte oxidative burst were evaluated and related to allometric indices and hematology. The humoral immune response to Edwardsiella ictaluri was evaluated fourteen days after treatment. Peripheral blood neutrophilia and specific antibody secreting cell (SASC) numbers were the most sensitive parameters and were affected in all three TBT treatment groups. Allometric indices, peripheral blood lymphocyte and monocyte percentages, NCC activity, and phagocyte oxidative burst were less sensitive and were affected only at the highest dose of TBT.

Animals↗
PubMed1992

Systemic treatment with murine recombinant interleukin-1 beta inhibits the growth and progression of malignant glioma in the rat.

We investigated the effects of daily subcutaneous (SC) injections of 100, 200, or 400 micrograms/kg murine recombinant interleukin-1 beta (rIL-1 beta) or its excipient on normal Fischer 344 rats and ones harboring a malignant RT-2 glioma. The tumor model has a predictable course with animals dying on days 14-17 following an intracerebral inoculation of 10(4) RT-2 glioma cells. Treatments with rIL-1 beta or excipient began on day seven post-tumor inoculation and continued for 7 days. We observed no significant effect on core body temperatures although there was a significant (p less than 0.05) decrease in body weight in all rIL-1 beta treated animals. When tumor-bearing animals became moribund, they received an intraperitoneal injection of bromodeoxyuridine (BUdr) and were sacrificed two hours later. Blood samples were obtained prior to their sacrifice by transcardiac perfusion with a buffered aldehyde solution. Recombinant IL-1 beta affected blood differentials; causing neutrophilia, lymphopenia, and slight thrombocythemia. The BUdr labeling index of glioma cells did not significantly differ between treatment groups, although tumors differed histologically at the time of necropsy. Tumors of rIL-1 beta treated animals had more extensive necrosis and a greater degree of leukocyte infiltration. Survival studies were conducted in which rats were given continuous daily SC injections of rIL-1 beta until day of death. Overall survival between the two groups differed significantly in studies using 100 micrograms/kg/d (p less than 0.05); rIL-1 beta treated rats had a mean survival time of 22 (+/- 3.0) days while excipient controls had a mean survival time of 17 (+/- 0.5) days. Similarly, at a dose of 200 micrograms rIL-1 beta/kg/d, mean survival was significantly (p less than 0.05) increased as compared to excipient controls (18.75 +/- 1.5 vs. 15.25 +/- 1.7 days, respectively). Daily injections of 400 micrograms/kg did not significantly increase the survival of glioma bearing animals, possibly as a consequence of rIL-1 beta toxicity at this dose.

Animals↗
PubMed1992

Microbial contamination in two antimicrobial and four control brands of alginate impression material.

Previous investigations have revealed commercial alginate impression material to be contaminated with viable microorganisms. Some manufacturers are now producing alginate materials that contain antimicrobial agents. The purpose of this study was to test and compare two antimicrobial and four control brands without antimicrobial agents of commercial dental alginate impression material for the presence of viable microorganisms. Forty-eight or 96 measured samples of each brand were taken from previously unopened containers using a sterile technique. The samples were placed on chocolate agar plates and in thioglycolate broth tubes and were incubated along with appropriate parallel controls. After incubation, colonies were enumerated, gram-stained, and identified using standard microbiologic methods. The two antimicrobial brands contained viable organisms in 12.5% of the samples incubated on agar media and also contained such organisms from 0% to 16.7% of the samples incubated in thioglycolate media. The four control brands contained viable organisms in from 29.2% to 100% of the samples incubated on agar media and also contained these organisms in from 25% to 79.2% of the samples incubated in thioglycolate media. There was a statistically significant difference (p less than 0.05) in contamination frequencies among some brands. Contamination frequencies of the top and middle portions of the containers did not differ significantly. The concentration of organisms in contaminated samples was 2.8 colony-formed units (CFUs) per gram for the antimicrobial alginates, and from 9 to 161.1 CFUs per gram for the control brands.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinomyces↗
PubMed1992

Intraoral vesicles occurring after alginate impressions.

In 47 of 227 dental students intraoral vesicles developed after multiple alginate impressions. The lesions were generally solitary and clear, and appeared within 24 to 48 hours after the impression. They were most frequently located inside the vermilion border of the lips and resolved spontaneously in 2 to 5 days. The purpose of this study was to determine the cause of these reactions. Histopathologically one lesion was suggestive of a contact allergy. Cutaneous patch tests, which proved negative, were performed on 14 students to determine whether an allergy to the alginate flavoring existed. The surface of three lesions were cultured and the organisms identified. Contamination studies were carried out on seven unopened containers of the alginate powder and resulted in the isolation of some organisms similar to the mucosal cultures; however, no relationship can be proved. These findings indicate that the cause of the vesicles remains unknown, and further studies are necessary to establish the cause.

Alginates↗
PubMed1991

Microbial contamination in four brands of irreversible hydrocolloid impression materials.

A previous investigation showed unopened irreversible hydrocolloid impression material to be contaminated with viable microorganisms. This study tested and compared four brands of commercial irreversible hydrocolloid impression material in factory-sealed containers for the presence of viable microorganisms. Twenty-four measured samples of each brand were taken from previously unopened containers using a sterile technique. The samples were placed on chocolate agar plates or in thioglycolate broth tubes and were incubated along with appropriate parallel controls. After incubation, colonies were enumerated, stained with Gram's stain and identified using standard microbiologic methods. The four brands contained viable organisms in 50% to 100% of the samples incubated of agar media, and in 12% to 67% of the samples incubated in thioglycolate media. Samples from the top and middle portions of the containers had approximately equal contamination frequencies. The concentration of organisms varied from 12 to 82 colony-formed units per gram of contaminated sample. Most organisms isolated were common environmental contaminants. These samples contained viable microorganisms which, during routine use, may present a hazard to immunocompromised patients.

Actinomyces↗
PubMed1991

Bacterial contamination in irreversible hydrocolloid impression material and gingival retraction cord.

This study tested two dental materials in factory-sealed containers for the presence of bacteria that may be a source of infection. Twenty samples of two dental materials found to have contamination in a pilot study were taken from unopened containers using a sterile technique. The samples were inoculated onto chocolate agar plates and into thioglycolate broths with appropriate controls. Plates were examined, colonies were enumerated, Gram stained, and identified. The resulting contamination frequencies were compared for statistical significance using Fisher's exact test. Organisms were isolated from 10% of the negative inoculation control agar plates, while none of the control broths showed contamination. The alginate (irreversible hydrocolloid) showed contamination in 50% of the plates and in 65% of the broths (p less than 0.05). The retraction cord had a small sample size and yielded organisms on 5% of the sample plates and in 20% of the thioglycolate broths (p greater than 0.05).

Alginates↗
PubMed1990

Orbital intramuscular schwannoma.

In an 8-year-old girl with asymptomatic proptosis, computed tomographic scans showed a large medial orbital mass that contoured the globe anteriorly, bowed the optic nerve laterally, and extended posteriorly to the orbital apex. T1-weighted coronal magnetic resonance images showed the mass to be a diffusely enlarged medial rectus muscle. Histopathologic examination of a medial rectus muscle biopsy specimen disclosed a multinodular, intramuscular schwannoma, separating and infiltrating normal skeletal muscle fibers. The intramuscular location and multinodular configuration of this tumor, together with its occurrence in a child, distinguish it from previous orbital schwannomas.

Biopsy↗
PubMed1990

Ocular and systemic findings in the Aarskog (facial-digital-genital) syndrome.

The Aarskog (facial-digital-genital) syndrome is an X-linked disorder in which short stature is accompanied by hypertelorism, digital anomalies, and shawl scrotum. Except for hypertelorism and blepharoptosis, ophthalmic abnormalities have been rarely noted in this condition. We examined four patients who had Aarskog syndrome and unilaterally or bilaterally decreased vision on initial examination. Three family members had V-pattern esotropia, latent nystagmus, inferior oblique overaction, and amblyopia. A fourth patient had bilateral blepharoptosis and severe astigmatism. Other ocular features included hyperopia, anisometropia, deficient ocular elevation, blue sclerae, and posterior embryotoxon. These findings underscore the need for ophthalmic examination in asymptomatic patients with Aarskog syndrome to rule out treatable causes of visual loss.

Abnormalities, Multiple↗
PubMed1990

Primary orbital melanoma associated with orbital melanocytosis.

We report a case of primary orbital melanoma in a 17-year-old girl. The patient presented with painless proptosis during the first trimester of pregnancy. Computed tomography demonstrated a well-circumscribed mass located infra-temporally in the right orbit. The tumor was bluish-black, grossly encapsulated, and associated with orbital blue nevi. Histologic examination of the mass revealed a pigmented spindle-cell neoplasm. On electron microscopy, the presence of premelanosomes and the absence of basal lamina supported the diagnosis of melanoma. Malignant transformation of a preexisting nevus is postulated since perineural foci of benign dendritic melanocytes were seen within the melanoma. There has been no recurrence or metastasis in a 2-year follow-up. Of 30 primary orbital melanomas reviewed, 12 (40%) were associated with periorbital pigmentary disorders, such as oculodermal melanocytosis, blue nevus, and ocular melanocytosis. Our case is unique since the pigmentary lesions were limited to the orbital tissues.

Adolescent↗
PubMed1990

Effect of murine recombinant interleukin-1 on brain oedema in the rat.

We investigated the effects of murine recombinant interleukin-1 (rIL-1, Du Pont) in vivo in the normal rat brain and here report both local and systemic effects of centrally administered rIL-1. Normal rats were given single or multiple atraumatic doses of either rIL-1 or and equal volume (5 microliters) of vehicle for control comparison. All dosages of intraparenchymal rIL-1 produced a uniform a hyperthermic response and concomitant lethargy. There was a related anorexia beyond fever duration. Histologic examination of intraparenchymal injection tracts revealed fibrillary whorls of oedema and a cellular infiltrate surrounding the rIL-1 tract, while similar changes were less prominent in control injection tracts. Repeated high doses of rIL-1 produced significantly higher concentrations of brain water as measured by the gravimetric technique. We conclude that rIL-1 is not only a potent chemoattractant, but is also an edigematic agent when administered in high doses.

Animals↗
PubMed1990

Aerobic bacterial contamination in dental materials.

Current concern about disease transmission points out the need for better infection control in dentistry. The purpose of this study was to test samples of dental materials in factory-sealed containers for aerobic bacterial contamination. Multiple unopened containers of 12 different dental materials were obtained from the dental school dispensary. Samples were removed from each container and incubated at 38 degrees C in standard broth medium for 1 week. Those that exhibited visual signs of possible bacterial growth were subjected to a Gram stain for verification. The results of that test indicated that 20% to 30% of the samples of alginate, glass ionomer cement and base powders, and retraction cord contained bacterial contamination. The remaining eight dental materials exhibited no apparent bacterial growth. Thus viable aerobic organisms were found in samples from 4 of 12 dental material products.

Air Microbiology↗
PubMed1989

An orbital hemangiopericytoma recurrent after 33 years.

A middle-aged woman developed a recurrent orbital hemangiopericytoma 33 years following its initial removal. Preoperative computed tomographic and magnetic resonance imaging scans revealed a well-circumscribed superotemporal orbital mass. A tumor that appeared grossly encapsulated was removed intact via a lateral orbitotomy. Histopathological examination showed a hemangiopericytoma with hypercellularity and a moderate number of mitotic figures. A review of the initial pathologic report confirmed the diagnosis of hemangiopericytoma with histological features similar to those of the recurrent mass. To our knowledge, this case represents the longest reported interval to recurrence of any hemangiopericytoma and demonstrates the extended follow-up needed in patients with hemangiopericytoma.

Female↗
PubMed1989

Cryotherapy for trichiasis in trachoma.

Trichiasis secondary to trachoma was treated in 137 eyelids from 64 patients in Saudi Arabia. Cryotherapy with high-flow nitrous oxide was applied to the lid margin for 45 seconds in a freeze-thaw-freeze cycle. The success rate of treated eyelids was 56% after one treatment and increased to 90% after a second treatment. Hypopigmentation of the highly pigmented eyelids of the Saudi population was our most significant complication (8% of treated lids). Because cryotherapy is portable and cost-effective and can be administered by paramedical personnel, it is ideal for use in regions where trachoma is endemic.

Adolescent↗
PubMed1988

Absence of Chlamydia in trachomatous lacrimal sacs.

We performed lacrimal sac biopsies in 35 patients who underwent dacryocystohinostomies in Saudi Arabia. The nasolacrimal duct obstructions were presumably secondary to trachoma in 22 cases and unknown in the remaining 13 cases. Lacrimal sac specimens were submitted for routine histopathologic examination and the direct-smear fluorescent antibody test. All specimens were negative for chlamydia. Possible reasons for the low detection rate of chlamydia in the trachomatous group were the frequent finding of clinically inactive disease, common canalicular obstruction, and loss of the epithelial lining in the lacrimal sac.

Adult↗