Ninety-day feeding study in Fischer-344 rats of highly refined petroleum-derived food-grade white oils and waxes

Subchronic 90-day feeding studies were conducted in male and female Fischer-344 (F-344) rats on highly refined white mineral oils and waxes representative of those used for food applications. The goal was to help clarify the mixed results found in other toxicity studies with laboratory animals. Seven white oils and 5 waxes were fed at dietary doses of 20,000, 2,000, 200, and 20 ppm and compared with control groups on untreated diet; toxicity was assessed at 90 days and also after a reversal period of 28 days and/or 85 days. Higher molecular-sized hydrocarbons (microcrystalline waxes and the higher viscosity oils) were without biological effects. Paraffin waxes and low- to midviscosity oils produced biological effects that were inversely related to molecular weight, viscosity, and melting point; oil type and processing did not appear to be determinants. Biological effects were more pronounced in females than in males. Effects occurred mainly in the liver and mesenteric lymph nodes and included increased organ weights, microscopic inflammatory changes, and evidence for the presence of saturated mineral hydrocarbons in affected tissues. Inflammation of the cardiac mitral valve was also observed at high doses in rats treated with paraffin waxes. Further studies are required to elucidate the mechanism for the responses observed and the relevance of these inflammatory responses in the F-344 rat to other species, including humans.

Variable responses of species and strains to white mineral oils and paraffin waxes

Recent dietary studies on mineral hydrocarbon (MHC) white oils and waxes have shown inflammatory effects in Fischer 344 (F-344) rats, but not in other rat strains or dogs. Histopathologic effects seen in F-344 rats include mesenteric lymph node histiocytosis, liver granulomas, and inflammation of the mitral valve (only seen with paraffin waxes). Human ingestion of MHC can result in noninflammatory lipogranulomas (oil droplets) in tissues which are regarded as clinically unimportant. It is speculated that inherent interspecies differences in pharmacokinetics and/or immune function may contribute to the differential response to MHC seen in F-344 rats. The F-344 rat retains greater amounts of MHC in target tissues compared to other rat strains and dogs and appears to be more sensitive immunologically to MHC than other species, including humans. This strain may be predisposed to these effects as indicated by a high background incidence of inflammatory granulomatous lesions in control female F-344 rats. Because of its apparently unique sensitivity, relevance of effects seen in F-344 rat to human health is questionable and requires further investigation.

The pathology of hysterectomy specimens following trans-cervical resection of the endometrium

The pathological findings in 29 hysterectomy specimens from a series of 175 patients undergoing trans-cervical resection of the endometrium are presented. In all but one case endometrium was present. Although all phases of the normal menstrual cycle were represented, in nine (28%) cases the endometrium appeared inactive, sometimes showing appearances similar to those in Asherman's syndrome. Adenomyosis was present in five (17%) cases and simple hyperplasia in one case. Haematocolpos was present in two cases. Inflammation was uncommon, usually mild in degree and present in the superficial myometrium. Four (14%) cases contained epithelioid or foreign body granulomas in the superficial myometrium. Deposits of haemosiderin and amorphous brown and/or particulate black pigment were seen in a total of 20 (69%) cases. A combination of transmission electronmicroscopy and energy dispersive analysis of X-rays showed these pigments to be a combination of charred organic material and metals, the latter corresponding to the composition of the diathermy cutting loop and electrocautery rollerball used in the ablative surgery.

Microform Calibration Uncertainties of Rockwell Diamond Indenters

National and international comparisons in Rockwell hardness tests show significant differences. Uncertainties in the geometry of the Rockwell diamond indenters are largely responsible for these differences. By using a stylus instrument, with a series of calibration and check standards, and calibration and uncertainty calculation procedures, we have calibrated the microform geometric parameters of Rockwell diamond indenters. These calibrations are traceable to fundamental standards. The expanded uncertainties (95 % level of confidence) are ±0.3 μm for the least-squares radius; ±0.01° for the cone angle; and ±0.025° for the holder axis alignment calibrations. Under ISO and NIST guidelines for expressing measurement uncertainties, the calibration and uncertainty calculation procedure, error sources, and uncertainty components are described, and the expanded uncertainties are calculated. The instrumentation and calibration procedure also allows the measurement of profile deviation from the least-squares radius and cone flank straightness. The surface roughness and the shape of the spherical tip of the diamond indenter can also be explored and quantified. Our calibration approach makes it possible to quantify the uncertainty, uniformity, and reproducibility of Rockwell diamond indenter microform geometry, as well as to unify the Rockwell hardness standards, through fundamental measurements rather than by performance comparisons.

Gas plasma sterilization--application of space-age technology

Gas plasma sterilization is new to the healthcare field. The first such sterilizer has been manufactured by Advanced Sterilization Products (J&J, Irvine, CA). The system uses hydrogen peroxide as the substrate gas and radio frequency emissions to generate plasma. This system is a low-temperature, quick-acting process with no toxic residues. It appears that this sterilizer system holds promise in the healthcare field and could help to reduce the use of ethylene oxide.

Synthesis and biological evaluation of imidazole based compounds as cytochrome P-450 inhibitors

Several phenyl ethyl and phenyl propyl imidazole based compounds have been synthesised and their biological activity evaluated against human placental Aromatase (AR), rat testicular 17 alpha-hydroxylase/ 17,20-lyase (P450(17) alpha) and bovine cholesterol side chain cleavage (CSCC). The compounds showed good selectivity towards AR with N-[2-(4'-Nitrophenyl) ethyl] imidazole (2) (IC50 = 0.16 +/- 0.01 microM, Ki = 0.09 +/- 0.01 microM), the most potent AR inhibitor, showing some 130 times greater potency over Aminoglutethimide (AG) (IC50 = 20.0 +/- 2.6 microM, Ki = 11.0 +/- 2.0 microM). N-[3-(4'-Fluorophenyl) propyl] imidazole (10) (IC50 = 0.31 +/- 0.01 microM, Ki = 0.34 +/- 0.05 microM), N-(2-(4'-Fluorophenyl ethyl) imidazole (5) (IC50 = 0.74 +/- 0.01 microM, Ki = 0.40 +/- 0.02 microM), N-(3-(4'-Chlorophenyl propyl) imidazole (9) (IC50 = 0.82 +/- 0.02 microM) and N-[3-(4'-Nitrophenyl) propyl] imidazole (7) (IC50 = 0.84 +/- 0.02 microM, Ki = 0.10 microM) were also more potent than AG. Of the compounds tested for P450(17) alpha activity, 7 (IC50 = 25.0 +/- 2.0 microM), N-[2-(4'-Aminophenyl) ethyl] imidazole (3) (IC50 = 27.6 +/- 0.10 microM), 9 (IC50 = 29.0 +/- 4.0 microM) and 2 (IC50 = 30.2 +/- 2.0 microM) showed the highest activity, possessing approximately half the activity of Ketoconazole (IC50 = 12.1 +/- 2.9 microM). Compounds 1, 2, 3, and 7 showed 0% inhibitory activity towards CSCC at 200 microM whilst AG showed 83% inhibition under the same conditions. The compounds proved themselves to be excellent lead compounds and supported the novel models developed by Ahmed for AR and P450(17) alpha.

Wide diversity in measurements of growth hormone after stimulation tests in short children are due to assay variability

A comparison of three commercially available assays for growth hormone (Pharmacia hGH RIA, IDS Gamma-BCT GH and Delfia 22 kDa hGH) were used to measure growth hormone (GH) secretion in 26 short children after pharmacological stimulation. The IDS Gamma-BCT assay was compared with Pharmacia assay in 15 provocative tests (13 children; n = 94). The Pharmacia assay showed a strong positive proportional bias and this was particularly marked at GH > 20 mU/L; the mean difference between the assays at GH < 10 mU/L was 12%. The IDS Gamma-BCT assay was also compared with the Delfia 22 kDa assay in 18 provocative tests (13 children; n = 100). Results from the IDS assay was higher throughout the range 0-90 mU/L with a mean difference of 11.4% in the range 10-90 mU/L; the mean difference between the assays at GH < 10 mU/L was -39%.

Synthesis and biological evaluation of novel pyrrolidine-2,5-dione inhibitors as potential anti-tumour agents

Several novel pyrrolidine-2,5-dione based compounds have been synthesised and evaluated for their biological activity against human placental aromatase (AR), rat testicular 17 alpha-hydroxylase/17,20-lyase (P450(17) alpha) and bovine cholesterol side chain cleavage (CSCC). The compounds showed good inhibition towards AR with 1-cyclohexyl-3-[2'(4"-aminophenyl) ethyl] pyrrolidine-2,5-dione (3) (IC50 = 23.8 +/- 4.6 microM) and 1-octyl-3-[2'(4"-aminophenyl) ethyl] pyrrolidine-2,5-dione (4) (IC50 = 24.6 +/- 1.8 microM) showing equipotent activity with Aminoglutethimide (AG) (IC50 = 20.0 +/- 2.6 microM, Ki = 11.0 +/- 2.0 microM). Of the compounds tested for P450(17) alpha activity, 3 (IC50 = 18.5 +/- 1.9 microM) again showed the highest activity, being equipotent to Ketoconazole (IC50 = 12.1 +/- 2.9 microM). 3 was a poor inhibitor of CSCC with some 22% inhibitory activity at an inhibitor concentration of 200 microM, as compared to AG with 72% inhibitory activity under the same conditions. The compounds proved themselves to be excellent lead compounds and supported the novel models developed by Ahmed for AR and P450(17) alpha.

From clinical ladders to a professional recognition program

A three-year process involving the redesign of clinical ladders led to a professional recognition program. After one year, a self-initiating credentialing ladder was established. The second year, one job description/performance evaluation was developed for bedside nurses--a professional ladder with system-wide and unit-specific requirements. Finally, during the third year, a professional recognition program emerged, recognizing expertise and experience.

Subchronic feeding study of four white mineral oils in dogs and rats

Subchronic 90-day feeding studies were conducted on four highly refined white mineral oils to determine any potential for toxicity in Long-Evans rats (20 per sex per dose level) and beagle dogs (4 per sex per dose level). Each oil was fed at dietary dose levels of 300 ppm and 1500 ppm (w/w). No treatment-related effects of toxicological importance were detected in daily observations of general health or in periodic assessments of food consumption and body weight, hematology, serum clinical chemistry, and urinalysis. Observations in dogs suggested that the white oils produced mild laxative effects. Gross and histopathologic examinations, as well as measurements of organ weights, did not reveal any macroscopic or microscopic changes which could be due to treatment. In addition, special staining by Oil Red O of liver, mesenteric lymph nodes, spleen, gastrointestinal tract, stomach, and kidneys indicated no evidence of oil or lipid deposition. A special re-examination of tissues from female and male rats, in response to more recent conflicting data from the Fischer 344 strain, found no histopathologic signs of macrophage accumulation and/or microgranuloma formation in liver, spleen, or mesenteric lymph nodes. These data indicate that repeated exposure to relatively high levels of white mineral oils in the diets does not produce significant subchronic toxicity in Long-Evans rats or beagle dogs.

Comparative 90-day feeding study with low-viscosity white mineral oil in Fischer-344 and Sprague-Dawley-derived CRL:CD rats

A 90-day study was conducted to compare the effects of dietary administration of a food-grade white oil in female Fischer-344 (F-344) and Sprague-Dawley-derived (CRL:CD) rats. Animals were fed a low viscosity (15 mm2/sec at 40 degrees C) paraffinic white oil (designated as P 15[H]) at 0, 0.2, or 2.0% of the diet for 30, 61, or 92 days. There were no significant adverse clinical observations or unscheduled deaths. In the F-344 rats, occasional treatment-related changes were seen in hematology and clinical chemistry parameters. At necropsy, mesenteric lymph nodes were enlarged, and there was an increase in absolute and relative liver, mesenteric lymph node, and spleen weights as compared to controls. Histopathologic effects included hepatic and mesenteric lymph node microgranulomas and mesenteric lymph node histiocytosis. In CRL:CD rats, the only effects noted were accumulations of chronic inflammatory cells in the liver at the high dose only, without the formation of discrete microgranulomas. A dose-related increase in mineral hydrocarbon (MCH) material in the liver and mesenteric lymph nodes was observed in both F-344 and CRL:CD rats. Although increased, liver MhC content was significantly less (approximately 50%) in CRL:CD rats than the levels detected in the F-344 rats. Mesenteric lymph node MHC levels did not differ significantly between the strains. This study demonstrated strain differences among rats in histopathologic effects of white oil, with the CRL:CD rat essentially showing no response compared to the F-344 rat.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of anal intraepithelial neoplasia

The natural history and malignant potential of anal intraepithelial neoplasia (AIN) remain uncertain, making management decisions about such lesions difficult. The management of 70 patients with AIN is described. The majority of lesions encountered were low grade (AIN I and II; 43 of 70) and required no treatment, but eight invasive anal cancers associated with high-grade AIN occurred over the 4-year study period. Three were a result of apparent progression of high-grade lesions; three more invasive lesions were found in areas of AIN III on histological examination. Surgical excision was used to treat 27 patients with AIN III. Treatment of extensive lesions involving the perianal and anal canal epithelium circumferentially in six patients involved excision of the whole of this epithelium and application of split skin grafts.

Inhibitors of sterol synthesis. Submicromolar 14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta, 15 alpha-diol causes a major modification of the sterol composition of CHO-K1 cells and a marked change in cell morphology

Incubation of Chinese hamster ovary cells (CHO-K1) with 14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta,15 alpha-diol (0.1 microM) in lipid-deficient medium led to a major change in cellular sterol composition, which was characterized by a very marked accumulation of C30 sterols (lanosterol and 24,25-dihydrolanosterol). The accumulation of C30 sterols was associated with a striking change in cell morphology. The change in cell shape (elongation) was similar to that described previously (A. W. Hsie and T. T. Puck, 1971. Proc. Natl. Acad. Sci. USA. 68: 358-361; and confirmed herein) for CHO-K1 cells incubated in the presence of dibutyryl cAMP (1 mM). This change in morphology, induced by dibutyryl cAMP, was not accompanied by a change in cellular sterol composition. The cell elongation and accumulation of C30 sterols, induced by the 14 alpha-ethyl diol, were prevented by the addition of cholesterol (10 microM or 100 microM) and were reversed by removal of the 14 alpha-ethyl diol from the incubation medium. Incubation of the cells with the 14 alpha-ethyl diol had no effect on the levels of cAMP under the conditions studied. Incubation of the cells with miconazole (10 microM) or with lanosterol (10 microM) was also associated with the accumulation of C30 sterols and an elongation of the cells. 24,25-Dihydrolanosterol (10 microM) also induced similar changes in cellular morphology. The results presented herein demonstrate that marked changes in the sterol composition of CHO-K1 cells can be effected by incubation of the cells with 14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta, 15 alpha-diol, miconazole, or lanosterol. In addition, the findings reported herein indicate an important role of sterols in the control of the shape of these cells.

Pathogenesis of human strongyloidiasis: autopsy and quantitative parasitological analysis

The distribution of pathologic lesions and the parasite burden of major organs were studied in seven patients with disseminated strongyloidiasis who were autopsied at the University of Texas Medical Branch (Galveston, TX). All patients were immunosuppressed and had additional bacterial, viral, and fungal infections; six patients had received cortisone therapy and one patient had AIDS. High Strongyloides burdens were noted in untreated patients or in those with a short period of treatment. The proximal small intestine and the lungs showed the heaviest parasite burden, with large numbers of filariform larvae found in both locations. The lungs showed persistence of larvae in all patients, in the absence of intestinal or extraintestinal infection; this suggests that the respiratory cycle may be more resistant to therapy than the intestinal cycle. In the intestines, filariform larvae were seen at all levels, but higher burdens were seen in the upper as compared to lower small intestine, and larvae were more concentrated in the proximal jejunum than in the duodenum. Autoinfection (i.e., filariform larval penetration) occurred more prominently in the distal small and proximal large intestine than in the distal colon. Most filariform larvae were found in the intestinal lymphatics and were highly concentrated in mesenteric and retroperitoneal lymph nodes; conversely, larvae were not found in the spleen and were found in very low density in the liver. These findings, in concert, suggest that during autoinfection in humans, the Stronglyloides larvae transverse lymphatics to the thoracic duct, then pursue a lymphohematogenous dissemination to the lungs where they penetrate the air spaces and ascend through the airways to reach the gut.

Necrotising granulomas of the uterine corpus

Images

Prevalence of anal human papillomavirus infection and intraepithelial neoplasia in renal allograft recipients

A study was performed to test the hypothesis that renal allograft recipients are at high risk of developing anal human papillomavirus (HPV) infection and anal intraepithelial neoplasia (AIN). A total of 133 renal allograft recipients and 145 control patients underwent anoscopy and biopsy. A polymerase chain reaction was used to detect HPV16 DNA in biopsy samples. A histological diagnosis of anal HPV infection or AIN was made in 32 allograft recipients (HPV infection, five; AIN I, 20; AIN II, three; AIN III, three; AIN III and anal cancer, one). One subject with AIN was detected in the control group. HPV16 DNA was detected in 47 and 12.4 per cent of anal biopsies in the allograft and control groups respectively. Renal allograft recipients are at high risk of developing anal HPV infection and neoplasia (P < 0.05). Further studies are required to determine whether screening anal examination is required in organ allograft recipients.

Anal human papillomavirus infection and squamous neoplasia in patients with invasive vulvar cancer

OBJECTIVE

To test the hypothesis that women with invasive vulvar cancer are at high risk of developing human papillomavirus (HPV)-associated anal squamous neoplasia.

METHODS

Forty women (median age 54.5 years; range 25-86) who were being treated or had been treated for invasive vulvar cancer and who had not had radiotherapy to the pelvis or anogenital region underwent anal microendoscopy and biopsy. A second group of 80 women who were similar in age to the study group and had no history of anogenital HPV infection or neoplasia formed the control group. The polymerase chain reaction was used to detect HPV 16 DNA in the vulvar and anal tissue samples from 33 patients in the study group and in the anal biopsies of all controls.

RESULTS

A histologic diagnosis of anal HPV infection or squamous neoplasia was made in 19 of 40 biopsies (47.5%) in the study group. These diagnoses consisted of one HPV, two anal squamous intraepithelial lesions (SIL) grade I, 15 and SIL grade III (four of which were associated with invasive anal cancers), and one invasive cancer in the absence of anal SIL. Human papillomavirus 16 DNA was detected in 16 of 33 (48.5%) of anal and 25 of 33 (75%) of vulvar biopsies. In addition, HPV 16 was detected in both the anal and vulvar samples in 13 of 16 cases (81%) of anal SIL III and invasive anal squamous cancer. No evidence of anal SIL was found in the controls, and HPV 16 DNA was identified in only 11 (13.7%) of the anal biopsies in this group.

CONCLUSIONS

This study provides further evidence for the etiologic relation between genital and anal squamous neoplasia. Furthermore, it shows that women with vulvar cancer are at high risk of having or developing HPV-associated anal neoplasia, particularly in younger patients (P = .0006; 95% confidence interval 12-34). Routine anal examination should be performed in patients with invasive vulvar cancer.

Immunohistochemical analysis of p53 expression in anal squamous neoplasia

AIMS

To determine the pattern of expression of the p53 tumour suppressor gene product in anal squamous neoplasia, and to determine if this could be used as a marker of disease progression. The association between p53 expression and human papillomavirus (HPV) 16 DNA status of the anal lesions was also investigated.

METHODS

The presence and localisation of the p53 protein in formalin fixed, paraffin wax embedded specimens of anal squamous epithelium (normal and neoplastic) was examined using immunohistochemical staining with a panel of two monoclonal antibodies (DO-1, DO-7) and one polyclonal antibody (CM-1). Thirty nine normal anal epithelia, 14 anal intraepithelial neoplasia (AIN) grade 1, seven AIN 2, and 20 AIN 3 specimens were obtained from patients without demonstrable invasive disease; twelve AIN 3 specimens adjacent to invasive disease and 34 anal squamous cancers were also examined. Genomic DNA from all 126 specimens was extracted and analysed for HPV 16 DNA using the polymerase chain reaction (PCR).

RESULTS

Nuclear p53 was strongly expressed in 67% (23/34) of invasive anal squamous tumours, 75% (9/12) of AIN 3 specimens adjacent to invasive disease, and in 60% (12/20) of AIN 3 specimens obtained from patients without demonstrable invasive disease. Two of the patients in the latter group with positively staining specimens subsequently developed invasive tumours which had staining characteristics similar to those of the AIN 3 specimens. p53 protein was expressed in very low concentrations in low grade AIN and not at all in normal anal squamous epithelium. In those specimens which stained positively for p53, HPV 16 DNA sequences were detected in 69.5% (16/23) of invasive disease, 77.7% (7/9) of AIN 3 adjacent to invasive disease, 75% (9/12) of AIN 3 obtained from patients without demonstrable invasive disease, 33.3% (2/6) of AIN 2, and in 40% (2/5) of AIN 1. There was no significant correlation between p53 immunostaining and HPV 16 DNA status (p < 0.05).

CONCLUSIONS

Aberrant expression of the p53 gene product is probably involved in the pathogenesis of anal squamous neoplasia. Long term follow up studies of all patients with AIN are required to determine if this could be used as a marker of likely disease progression from high grade AIN to invasive disease. There does not seem to be an association between the presence or absence of HPV 16 DNA sequences and mutant p53 proteins in anal squamous neoplasia.

C-myc oncogene expression in anal squamous neoplasia

AIMS

To determine the pattern of c-myc oncogene expression in anal squamous neoplasia and to determine if this could be used as a marker of disease progression.

METHODS

The presence and localisation of the c-myc gene product p62 in archival specimens of anal squamous epithelium, normal and neoplastic, was examined using immunohistochemical staining with the monoclonal antibody Myc1-6E10. Ten normal and epithelia, 10 anal intraepithelial neoplasia (AIN) III, and 31 anal squamous cancers were examined.

RESULTS

There was a noticeable difference between the staining characteristics of invasive tumours, normal anal epithelium, and AIN III. Intense, diffuse, mixed nuclear and cytoplasmic (n = 14) and exclusively nuclear (n = 8) staining in 22 of 31 (71%) of invasive anal tumours was observed. All positively staining tumours were well differentiated histologically, while the negatively staining nine of 31 (29%) were poorly differentiated (n = 7) and moderately well differentiated (n = 2). In six positively staining tumour sections adjacent areas of AIN III and non-dysplastic anal epithelium had staining characteristics similar to those of the invasive component. Staining in both normal anal epithelium (4/10) and AIN III specimens obtained from patients without a history of invasive disease (8/10) was less intense, focal in distribution, and exclusively nuclear. No difference in staining characteristics could be detected in these two groups.

CONCLUSIONS

The results of this study suggest that c-myc oncogene expression is implicated in the pathogenesis of anal squamous neoplasia, and that immunohistochemical staining for c-myc protein may be helpful in identifying those AIN III lesions most likely to progress to invasive tumours.

Non-alimentary aspects of the irritable bowel syndrome

The irritable bowel syndrome (IBS) is characterized by alimentary and non-alimentary symptoms; the aim of this study was to assess the clinical value and discriminant function of non-alimentary symptoms in the irritable bowel syndrome. Alimentary and non-alimentary symptoms, estimated daily dietary fibre intakes, ability to express personal feelings, anxiety and depression ratings, and life events and difficulties inventories were compared in 128 hospital out-patients with IBS and 113 age and sex matched control subjects not seeking health care, randomly recruited from the community. Alimentary symptoms correlated closely with those non-alimentary symptoms often associated with the hyperventilation syndromes, difficulties in expressing personal feelings and anxiety, and depression ratings. Life events and difficulties, and estimated daily dietary fibre intakes did not differ significantly between patients and controls. With the exception of abdominal bloating, no significant gender differences were observed in IBS symptoms in either the IBS or control groups. The irritable bowel syndrome is one facet of a more general condition of illness behaviour which includes the hyperventilation syndrome and an inassertiveness in expressing personal feelings. Though non-alimentary symptoms did not improve diagnostic accuracy beyond that achieved by a combination of alimentary symptoms, their recognition provides alternative approaches to the management of refractory IBS.