Intraepithelial leukocytes in endometriosis and adenomyosis: comparison of eutopic and ectopic endometrium with normal endometrium

Intraepithelial leukocytes (IEL) are recognized as an important component of most mucosal surfaces but have received scant attention in the human female reproductive tract. The aim of the present study was to characterize, quantify and compare IEL populations in normal endometrium (n = 30) and in eutopic and ectopic (endometriotic or adenomyotic lesions) endometrium from women with endometriosis (n = 30) or adenomyosis (n = 15) at different menstrual cycle phases in order to assess the role of IEL in these common but poorly understood disorders. IEL populations were examined in formalin-fixed, paraffin-embedded sections using a streptavidin-biotin-peroxidase complex technique and quantified in relation to epithelial cell numbers. IEL in control endometrium and eutopic endometrium in endometriosis and adenomyosis varied during the menstrual cycle, with CD45+, CD43+ and CD56+ cells increasing from the proliferative to the late secretory phase. IEL were elevated in surface compared with glandular epithelium in the proliferative and early secretory phases. Throughout the menstrual cycle there were no significant differences in IEL between eutopic and ectopic endometrium in adenomyosis. Endometriotic foci, however, contained elevated levels of CD45+, CD3+ and CD8+ cells and reduced numbers of CD56 + cells compared with the corresponding eutopic endometrium and these did not vary with menstrual cycle phase. In contrast, ectopic endometrium in adenomyosis showed some cyclical changes with CD56+ cells increasing significantly in the late secretory phase. It is possible these differences may play a role in the pathogenesis of endometriosis and the associated complications.

Phenotypic and functional studies of leukocytes in human endometrium and endometriosis

The aetiology of endometriosis, a common and disabling disorder, is presently unknown, although immune dysfunction could allow ectopic endometrial fragments to survive outside the uterine cavity. These studies investigate the relationship between leukocyte populations, steroid hormone receptor expression, proliferative activity, bcl-2 expression and apoptosis in eutopic and ectopic endometrium from women with endometriosis or adenomyosis at different phases of the menstrual cycle. Significantly increased oestrogen receptor expression, bcl-2 expression and numbers of CD8+ leukocytes were found in ectopic compared with eutopic endometrium in endometriosis, and CD56+ endometrial granulated lymphocytes (eGLs) were significantly reduced in ectopic endometrium. Apoptotic cells were rarely found in control and subject endometria. In contrast with endometriosis, adenomyotic lesions showed identical steroid hormone receptor expression, proliferative activity, bcl-2 expression and leukocyte subpopulations to eutopic endometrium, indicating different aetiologies for these disorders. The unusual CD56+ CD16- eGLs present in large numbers in late secretory phase eutopic endometrium were highly purified (>98%) by immunomagnetic separation. Except for a negligible cytotoxic activity of eGLs from early proliferative samples, cytotoxic activity of eGLs from non-pregnant endometrium during the menstrual cycle was comparable with those in peripheral blood, predominantly CD56+ CD16+ natural killer cells. eGLs from non-pregnant endometrium and early pregnancy showed a variable proliferative response to 5 and 100 U/ml interleukin-2 over 48-h and 120-h time courses. eGLs are evidently functionally important in the eutopic endometrium. Their absence in endometriotic lesions together with increased CD+8 T-cell numbers and increased oestrogen receptor and bcl-2 expression may have significant effects on the development and progression of endometriosis.

Women's lay knowledge of cervical cancer/cervical screening: accounting for non-attendance at cervical screening clinics

An assessment of women's knowledge of cervical screening and cervical cancer was considered important as up to 92% of those dying from this form of cancer had never been tested. What were the reasons which determined their non-attendance? Issues to be addressed were reactions to invitation, women's knowledge of screening, and the possible factors which they envisaged as being associated with cervical cancer. Other issues to be considered were practical problems associated with attendance, and preference for the sex and professional status of the health professionals involved; 187 women in a general practitioner practice in Lothian, Scotland were targeted by questionnaire. As with other studies in this field 50% of those contacted were ineligible for a variety of reasons. Seventy-two women completed the questionnaire, providing a mix of qualitative and quantitative data. Although the majority of women felt the invitation to attend screening was clear and easy to understand, there was a lack of knowledge with regard to both the screening itself and the possible causes of cervical cancer. The main 'causes' were seen as higher sexual activity among those aged under 37 and smoking and a virus by those over 37. The majority of women showed preference for a female professional to take the smear. Practical problems of time and venue were not considered insurmountable. The main reasons cited for non-compliance were the fear and dislike of the test itself.

Apoptosis, bcl-2 expression, and proliferative activity in human endometrial stroma and endometrial granulated lymphocytes

Human endometrial leukocytes undergo regular cyclical changes during the menstrual cycle, with a striking increase in the phenotypically unusual population of CD56+ CD16- endometrial granulated lymphocytes (eGLs) in the late secretory phase and early pregnancy. The factors that regulate this increase in eGL numbers are unclear; their unusual morphology, however, has led to the suggestion that they undergo apoptosis at the end of the menstrual cycle. Apoptosis, bcl-2 expression, and proliferative activity were examined in the stroma of normal cycling, progesterone-treated, and early-pregnancy endometrium. The expression of bcl-2 and the Ki67 proliferation marker by highly purified (> 98% CD56+) eGLs from endometrium during the menstrual cycle and from first-trimester decidua was also studied. Apoptotic cells were rarely observed in the endometrial stroma of any of the samples examined. Stromal bcl-2 expression, however, increased from the proliferative to the premenstrual phase, and double immunohistochemical labeling demonstrated large numbers of bcl-2+ CD56+ eGLs. In contrast, Ki67 expression was high in the endometrial stroma during the proliferative phase, fell during the secretory phase, and rose again premenstrually, because of expression by eGLs. Isolated CD56+ eGLs also showed high bcl-2 and Ki67 expression at the end of the menstrual cycle. Unlike premenstrual endometrium, progesterone-treated endometrium and first-trimester decidua contained few proliferating cells, expressed high levels of bcl-2, and showed no evidence of apoptosis. Thus, eGLs do not undergo apoptosis in premenstrual endometrium, and their regulatory mechanisms remain to be clarified.

Preliminary evaluation of the efficacy and implementation of the new NHS complaints procedure

The increase (28.8 per cent) in the number of complaints from pre-New NHS Complaints Procedure to the implementation of the new procedures in 1996 is a matter of concern because it is estimated that the current figure represents only 40 per cent of the number of people with some dissatisfaction. The Wilson Report prompted Government initiatives in producing a new NHS Complaints Procedure. The new procedure allows for complaints to be dealt with at a local level, or in a minority of cases through Independent Review. The new procedures, which were introduced in April 1996, oblige Trusts, GP practices and Health Boards to establish a Written Local Resolution process for handling complaints, responsibility for implementation lying with individual trusts. A preliminary assessment of the New Procedures was carried out in Lothian. A qualitative approach was utilised and semi-structured taped interviews lasting on average one hour ten minutes were administered to the six complaints officers. This study concentrates on how the six Lothian NHS Trusts are implementing the new procedure, the openness in complaints handling, and the awareness of how complaints can be used to improve standards. The conclusion is that Local Resolution 1 has been successful, and that complaints do receive a speedy response. The process is much simpler and easier for the lay population to access. Reservations remain, however, towards the Independent Review procedure.

Cytotoxic activity of endometrial granulated lymphocytes during the menstrual cycle in humans

CD56+ CD16- granulated lymphocytes, termed endometrial granulated lymphocytes (eGLs), have been suggested to play a role in the maintenance of human pregnancy, although their in vivo function in both pregnant and nonpregnant endometrium remains unknown. The present study compared the cytotoxic activity of CD56+ CD16- eGLs (> 98% purity) positively selected from early and late proliferative-phase, early and late secretory-phase, and menstrual-phase endometrium with that of CD56+ CD16- eGLs purified from first-trimester decidua and CD56+ predominantly CD16+ cells from peripheral blood. From the late proliferative phase onwards, the major histocompatibility complex (MHC)-nonrestricted cytotoxic activity of eGLs was comparable between phases of the menstrual cycle. In contrast, eGLs from early proliferative-phase endometrium displayed significantly lower cytotoxic activity. With the exception of eGLs purified from early proliferative-phase endometrium, the cytotoxic activity of CD56+ CD16- eGLs purified from nonpregnant endometrium was comparable to that of CD56+ CD16- eGLs in decidua and CD56+ predominantly CD16+ cells from peripheral blood. No endogenous lymphokine-activated killer cell activity was detected in eGLs from endometrium or decidua. The present study using highly purified eGLs demonstrates that, with the exception of early proliferative-phase samples, CD56+ CD16- eGLs from nonpregnant endometrium and early pregnancy decidua have cytotoxic activity comparable to that of "classical" natural killer cells from peripheral blood.

Managing pregnancy-related nocturnal nasal congestion. The external nasal dilator

OBJECTIVE

To assess the efficacy of an over-the-counter mechanical nasal dilator during sleep in pregnant women with nasal congestion.

STUDY DESIGN

Pregnant women with symptoms of nocturnal nasal congestion not attributed to allergies or "cold" symptoms were randomized in a double-blind manner to receive either a spring-loaded device or placebo device without a spring. Each patient assessed breathing and sleep quality for a three-day baseline and three-day treatment period. A 10-question diary was utilized to assess breathing, ease of falling asleep, sleep quality, and continuity and depth of sleep. Averaged scores for each question were computed for baseline and treatment periods, and differences were calculated. Statistical analyses were by the sign test, Fisher's exact test and Student's test.

RESULTS

Thirty-four (21%) of 160 screened patients were enrolled into the study; 24 (15%) completed the study. All agreed to being assigned to receive either the spring-loaded device (n = 12) or a placebo (n = 12) device. Responses to 8 of the 10 questions favored the former as compared with the placebo (P = .05, sign test). Moreover, patients treated with the spring-loaded device gave more favorable responses to the question, "Overall, compared with most nights, how easy was your breathing through-out last night?" (P = .02, t test).

CONCLUSION

Use of this drug-free external nasal dilator improved the ease of breathing among patients with pregnancy-related nocturnal congestion.

Immunohistochemical characterization of stromal leukocytes in ovarian endometriosis: comparison of eutopic and ectopic endometrium with normal endometrium

OBJECTIVE

To compare stromal leukocyte subpopulations in different phases of the menstrual cycle in eutopic and ectopic endometrium from women with ovarian endometriosis and in control endometrium.

DESIGN

Retrospective immunohistochemical study.

SETTING

Department of Pathology, Royal Victoria Infirmary, Newcastle-upon-Tyne, United Kingdom.

PATIENTS

Paraffin-embedded tissue blocks from 30 patients with endometriosis and 30 control blocks from patients undergoing hysterectomy for nonendometrial pathology were retrieved from archive files.

MAIN OUTCOME MEASURE

Quantitative assessment of defined stromal leukocyte subpopulations in eutopic, ectopic and control endometrium at different stages of the menstrual cycle.

RESULTS

In the proliferative and early secretory phases, ectopic endometrium contained elevated numbers of CD45+, CD3+, and CD43+ cells but reduced percentages of CD68+ macrophages. The proportions of granulated cells were reduced in ectopic endometrium throughout the cycle. No differences were noted between eutopic endometrium from women with endometriosis and control endometrium.

CONCLUSION

Differences between eutopic and ectopic leukocyte subpopulations with the exception of large granular lymphocytes may be due to the lack of cyclicity demonstrated by endometriotic lesions.

Nitrogen inputs from a pasture legume in rotations with cereals in the semi-arid tropics of northern Australia: experimentation and modelling on a clay loam soil

Two experiments on a Tippera clay loam soil (alfisol) at Katherine, Northern Territory, investigated the nitrogen (N) benefit from legume pasture leys of Caribbean stylo (Stylosanthes hamata cv. Verano) to subsequent maize crops. Nitrogen uptake and yield of the maize crops were higher after the Verano leys than after a grass ley, the effect persisting into the second crop. The 1-year Verano ley was estimated to have increased N uptake by the maize crops by about 30 kg/ha, and the 3-year ley by about 55 kgha over that for the grass. Removing some of the Verano dry matter (DM) as hay at the end of each growing season reduced the subsequent benefit compared with treatments where the Verano DM was rotovated into the surface soil at the end of each growing season, or left standing. However, in all legume treatments, the additional N contributed by the legume was inadequate to fully meet the N requirement of the following crop. The main features of the experimental results, through both the ley and cropping phases, could be simulated adequately using the cropping system model APSIM. The model provided the opportunity to explore the fate of N in the system, and gave insights into aspects of system performance that could not be obtained from the experimental data.

Influence of disease-suppressive strains of Streptomyces on the native Streptomyces community in soil as determined by the analysis of cellular fatty acids

Analysis of cellular fatty acid profiles was used to distinguish among introduced pathogen- suppressive strains and indigenous strains of Streptomyces spp. isolated from soil of field plots established to test the efficacy of Streptomyces strains PonSSII and PonR in the biological control of potato scab. Reference libraries of fatty acid profiles were developed for a collection of known pathogenic strains and the introduced suppressive strains. Population densities of pathogen-related, suppressive, and saprophytic Streptomyces strains were determined from the relationship of field isolates to mean library profiles using cluster analysis and the unweighted pair-group method using arithmetic averages. Community diversity was similarly determined. Streptomyces strains PonSSII and PonR were distinguished from each other and from the pathogen group (which clustered together) based on fatty acid profiles. The introduced, suppressive strains successfully colonized the soil and represented 2-19% of the isolates sampled over 2 years. The introduction of the suppressive strains inhibited the population of strains related to the pathogen library at each sample date; the pathogen population was substantially lower in soil from treatments where the suppressive strains were introduced compared with the nonamended control. At harvest, the pathogen-related population was suppressed 85-93 and 36-44% in 1991 and 1992, respectively, in treatments with the suppressive strains compared with the nonamended control. Diversity of the community was not affected by the introduced strains, and diversity and equitability indices were similar among treatments at any sample time. The inhibition of the pathogen-related population was correlated with a reduction of scab symptoms observed in the field plots into which the suppressive strains were introduced. Implications of a fundamental shift in the pathogen-related population in response to the introduction of the suppressive strains for long-term biological control of potato scab are encouraging.

Immunohistochemical characterization of proliferation, oestrogen receptor and progesterone receptor expression in endometriosis: comparison of eutopic and ectopic endometrium with normal cycling endometrium

Recent studies examining oestrogen and progesterone receptor status and the proliferative activity of endometriotic lesions have produced conflicting reports. This study aimed to clarify the receptor status and proliferative activity of eutopic and ectopic endometrium from women with endometriosis and endometrium from normal women. Progesterone and oestrogen receptor expression and proliferative activity were studied in eutopic and ectopic endometrium from 30 women with endometriosis and in endometrium from 30 normal cycling women using microwave-pretreated paraffin-embedded sections stained with an avidin-biotin peroxidase technique. Progesterone and oestrogen receptor expression in the control endometrium did not differ from that of eutopic endometrium from women with endometriosis. Oestrogen receptor expression in ectopic endometrium increased from the proliferative to the late secretory phase. Epithelial progesterone receptor expression decreased during the cycle. Oestrogen receptor expression in both epithelium and stroma of ectopic endometrium was significantly higher than in eutopic endometrium throughout the cycle. In contrast, stromal progesterone receptor expression tended to be reduced in ectopic endometrium compared with eutopic tissue. Epithelial progesterone receptor expression was increased in ectopic endometrium but only in the late secretory phase. Although proliferative activity in the epithelium of control and eutopic endometrium was reduced from the proliferative to the late secretory phase, stromal activity did not vary. The proliferative activity in ectopic endometrium remained low and constant throughout the cycle. In the proliferative and early secretory phases, the proliferative activity of eutopic endometrium was increased compared with ectopic endometrium, but in the late secretory phase, levels were comparable. These findings challenge previous reports which have suggested that oestrogen receptors are reduced in ectopic tissue. This may have clinical implications for the development of novel treatments for endometriosis.

Polysomnography methods and interpretations

As the field of sleep disorders medicine continues to mature, appropriate diagnostic techniques are becoming properly defined and standardized. This article focuses principally upon diagnostic testing for sleep apnea, although other sleep disorders are discussed briefly. When interpreting a polysomnogram, one must consider a number of complex variables. A critical discussion of the methods for adequately measuring these variables is provided together with guidelines for appropriate interpretation.

Effect of phosphorus supply on three perennial Stylosanthes species in tropical Australia. III. Potassium, calcium, magnesium and sodium concentrations and implications for grazing animals

Thc effect of phosphorus application (0 and 50 kg P ha-1 as triple superphosphate) on potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na) concentrations in three Stylosanthes species (S. scabra cv. Seca, S. pianensis cv. Schofield and S. viscosa CPI 34904) was examined in a field experiment. Regular measurements were made of these cations in the leaves, stems, inflorescence, seed and litter of established plants during the wet and dry seasons of 1978-79.Phosphorus supply did not affect K, decreased Ca, increased Mg, and in some fractions increased Na concentration. It decreased the ratio of Ca to P. Applied P had no effect on the changes in cation concentration through time. With increasing plant age, K decreased in leaves of all species, Ca decreased in Seca and Schofield (but remained constant in CPI 34904), Mg was relatively steady in all species, and Na decreased in Seca and CP134904 but not Schofield. A comparison of cation concentrations in intact leaves and leaf litter suggests there was remobilization of K, and to a lesser degree, Na and Mg, but not Ca from old leaves prior to senescence.Potassium and Ca in leaf and green stem were generally considered adequate for cattle requirements throughout the year. However, Mg and Na often fell below the level required for cattle growth. The wide Ca/P ratio combined with low P concentration in all species suggests that cattle grazing these pastures would respond to P supplementation.

Effect of phosphorus on three perennial Stylosanthes species in tropical Australia. II. Phosphorus and nitrogen within the plant and implications for grazing animals

This paper describes the effect of phosphorus application on concentrations and distribution of phosphorus (P) and nitrogen (N) in three Stylosanthm specics (S. scabra cv. Scca, S. guiunensis cv. Schofield and S. viscosa CPI 34904) grown in the field on a soil of low acid-extractable (0.005 M H2SO4) P status (4 mg/kg). Over a two-year period (May 1978 to September 1979), regular measurements were made of P and N in whole plant shoots, leaves, stems, inflorescence, seed and litter.Phosphorus application increased P concentrations in all three legumes, but did not affect its pattern of seasonal change throughout the year. The P (and N) concentrations in most plant parts decreased through the wet season to reach minima in the late dry season. However, with seed there was little seasonal variation. In the second year, Seca was more efficient at taking up P and utilizing it for growth under low soil P conditions than Schofield. CPI 34904 was less efficient than Seca at taking up P, but also used P efficiently for growth. The efficient utilization of P in the leaves and stems of Seca and CPI 34904 meant that P levels were often below the level (0.12%) considered adequate for growth of grazing cattle. Dry season P concentrations in all legumes were inadequate. When P was applied, P concentrations in leaf and green stem of all species were higher than 0.12% during the wet season, but green stem of Seca and CPI 34904 fell below this level during the dry season.Applied P slightly increased N concentrations in leaves, green stems and whole plants of all species. Nitrogen concentrations were adequate (> 1.1% N) for maintenance of cattle weight at most times. Only in the late dry season did green stem of Seca contain insufficient N.Phosphorus application had little effect on the distribution of P and N within the plants. All species held a large percentage (20-50%) of these nutrients in green stems, but CPI 34904 was exceptional in directing up to 60% of the P and N to inflorescence and seed at the expense of leaf and stem.

Response of rodents to inhaled diluted diesel exhaust: biochemical and cytological changes in bronchoalveolar lavage fluid and in lung tissue

The effect of long-term (24 months) inhalation of diesel exhaust on the bronchoalveolar region of the respiratory tract of rodents was assessed by serial (every 6 months) analysis of bronchoalveolar lavage fluid (BALF) and of lung tissue from F344/Crl rats and CD-1 mice (both sexes) exposed to diesel exhaust diluted to contain 0, 0.35, 3.5, or 7.0 mg soot/m3. The purpose of the study was twofold. One was to assess the potential health effects of inhaling diluted exhaust from light-duty diesel engines. The second was to determine the usefulness of BALF analysis in detecting the early stages in the development of nononcogenic lung disease and differentiating them from the normal repair processes. No biochemical or cytological changes in BALF or in lung tissue were noted in either species exposed to the lowest, and most environmentally relevant, concentration of diesel exhaust. In the two higher levels of exposure, a chronic inflammatory response was measured in both species by dose-dependent increases in inflammatory cells, cytoplasmic and lysosomal enzymes, and protein in BALF. Histologically, after 1 year of exposure, the rats had developed focal areas of fibrosis associated with the deposits of soot, while the mice, despite a higher lung burden of soot than the rats, had only a fine fibrillar thickening of an occasional alveolar septa in the high-level exposure group. Higher increases in BALF beta-glucuronidase activity and in hydroxyproline content accompanied the greater degree of fibrosis in the rat. BALF levels of glutathione (GSH) and glutathione reductase activity increased in a dose-dependent fashion and were higher in mice than in rats. Lung tissue GSH was depleted in a dose-dependent fashion in rats but was slightly increased in mice. This depletion may have played a role in the greater fibrogenic response observed in rats. Other tissue changes in enzymatic activity were small compared to changes observed in BALF. The exposure did not increase the cytochrome P-450 content of the lung in either species. The results suggest that, for the noncarcinogenic health effects reported in this paper, there is a threshold of exposure below which adverse effects were not observed. This threshold was well above environmentally relevant levels of diesel exhaust but may be in the range of some occupational exposures. The analysis of BALF proved a useful adjunct to the chronic toxicity study to quantitate the inflammatory changes accompanying the development of pulmonary disease.

Children's perception of certain musical properties: scale and contour

Children's perception of scale and contour in melodies was investigated in five studies. Experimental tasks included judging transposed renditions of melodies (Studies 1 and 3), discriminating between transposed renditions of a melody (Study 2), judging contour-preserving transformations of melodies (Study 4), and judging similarity to a familiar target melody of transformations preserving rhythm or rhythm and contour (Study 5). The first and second studies showed that young children detect key transposition changes even in familiar melodies and they perceive similarity over key transpositions even in unfamiliar melodies. Young children also are sensitive to melodic contour over transformations that preserve it (Study 5), yet they distinguish spontaneously between melodies with the same contour and different intervals (Study 4). The key distance effect reported in the literature did not occur in the tasks of this investigation (Studies 1 and 3), and it may be apparent only for melodies shorter or more impoverished than those used here.

Diesel exhaust is a pulmonary carcinogen in rats exposed chronically by inhalation

Male and female F344 rats were exposed 7 hr/day, 5 day/week for up to 30 months to automotive diesel engine exhaust at soot concentrations of 0.35, 3.5, or 7.0 mg/m3 or were sham-exposed to clean air. Rats were terminated at 6-month intervals to measure lung burdens of diesel soot and for histopathology. Other rats either died or were terminated after 30 months of exposure. Lungs were fixed, sectioned into 3-mm slices, and examined by a dissecting microscope to detect tumors. Lesions were stained and examined by light microscopy. Survival and body weight were unaffected by exposure. Focal fibrotic and proliferative lung disease accompanied a progressive accumulation of soot in the lung. The prevalence of lung tumors was significantly increased at the high (13%) and medium (4%) dose levels above the control prevalence (1%). Four tumor types, all of epithelial origin, were observed: adenoma, adenocarcinoma, squamous cyst, and squamous cell carcinoma. Logistic regression modeling demonstrated a significant relationship between tumor prevalence and both exposure concentration and soot lung burden. These results demonstrate that diesel exhaust, inhaled chronically at a high concentration, is a pulmonary carcinogen in the rat.

Single inhalation exposure to 90SrCl2 in the beagle dog: hematological effects

The toxicity of 90Sr administered by the inhalation route was studied in young adult Beagle dogs exposed once to aerosols containing 90SrCl2. Due to its relatively soluble chemical form, 90Sr was rapidly translocated from lung to bone where a substantial portion was retained for a long period of time. This resulted in only a brief radiation exposure of the respiratory tract and a protracted exposure of the skeleton. The long-term retained burdens ranged from 0.037 to 4.4 MBq 90Sr/kg body wt. Dogs were subsequently observed throughout their life span. Six dogs with long-term retained burdens of 1.7 to 4.1 MBq 90Sr/kg died at less than 32 days after exposure from radiation-induced bone marrow hypoplasia. Review of hematological parameters of all dogs showed a similar, consistent, and dose-related pancytopenia in those animals having a long-term retained burden of greater than 0.37 MBq 90Sr/kg. Thrombocytopenia and neutropenia persisted in all exposed dogs through 1000 days after exposure. For reference purposes, a burden of 0.37 MBq 90Sr/kg is calculated to deliver an average radiation dose to the skeleton over 30, 100, and 1000 days after intake of 1.0, 2.8, and 17 Gy, respectively. The hematologic changes were similar to those seen in people exposed to high doses of whole-body external radiation.

Deposition, metabolism, and excretion of 1-[14C]nitropyrene and 1-[14C]nitropyrene coated on diesel exhaust particles as influenced by exposure concentration

Nitrated polycyclic aromatic hydrocarbons (nitro-PAH) have been detected in the environment, originating from sources such as diesel exhaust emissions and coal combustion fly ash. 1-Nitropyrene (NP) is a predominant mutagenic and carcinogenic nitro-PAH found in diesel exhaust emissions. Since inhalation of NP is a likely route of exposure in humans, it is important to determine the biological fate of inhaled NP both in its pure form and associated with particles. The purpose of this study was to determine the disposition of NP aerosols inhaled by rats. The studies described in this paper were designed to determine the deposition of [14C]NP over a range of exposure concentrations, identify the pathways and half-times for excretion of absorbed NP, and determine the distribution of inhaled NP and metabolites in tissues. Male F344 rats were exposed nose only to various concentrations of NP and NP coated on diesel exhaust particles (50-1100 ng/liter). The results indicate that, over the range of concentrations tested, pathways for excretion of [14C]NP equivalents in urine and feces were independent of the exposure concentration of NP, whether in its pure form or associated with diesel exhaust particles. In all cases, fecal excretion was the major route of elimination of [14C]NP equivalents, with about 2 times more excreted by this route than by urine. The fractional deposition of [14C]NP in the respiratory tract did not appear to be dependent on exposure concentration. Half-times for elimination of 14C in urine and feces were about 15 to 20 hr. In all exposures, 14C was widely distributed in the tissues examined. Analysis of the tissues for NP and its metabolites indicated that within 1 hr after exposure, greater than 90% of the 14C was NP metabolites. Lungs of rats exposed to [14C]NP coated on diesel exhaust particles contained nearly 5 times more 14C than lungs from rats exposed to pure aerosols of [14C]NP (148 vs 29 pmol/g lung) within 1 hr after exposure. This difference was increased to 80-fold at 94 hr after exposure (80 vs 1 pmol/g lung). Long-term clearance half-times of 14C from various tissues were similar. The results demonstrate that particle association of NP significantly alters the biological fate of inhaled NP.