The effect of glasses on visual function following cataract surgery in a cataract camp.

AIM: To investigate visual and functional impact of glasses following cataract surgery in a high-volume cataract camp as measured by the World Health Organization Prevention of Blindness Visual Function Questionnaire (WHO/PBD-VFQ-20). METHOD: Subjects were administered the WHO/PBD-VFQ three times: (1) preoperatively; (2) 3 months postoperatively, before glasses; and (3) 6 months postoperatively, after 3 months with glasses. Patients were given prescription glasses or +2.50 readers at the 3-month follow-up. RESULTS: 315 patients enrolled in the study; 113 patients had complete WHO/PBD-VFQ and visual acuity data from all three administrations. The mean preoperative visual acuity in the surgical eye was 20/327. Following cataract surgery but before glasses, visual acuity improved to 20/57. Total WHO/PBD-VFQ and subscale scores improved significantly at the 3-month point. With glasses, visual acuity improved to 20/43. Total WHO/PBD-VFQ scores did not change following glasses, although the overall and near vision subscales did improve significantly. Glasses were worn once per week or less in 56% of patients. CONCLUSION: Postoperative glasses result in modest improvements in visual acuity. Total WHO/PBD-VFQ scores did not change significantly following glasses, but the overall and near vision subscales did improve. The net beneficial effect of glasses was small relative to cataract surgery itself.

Hypoxic inhibition of human cardiac fibroblast invasion and MMP-2 activation may impair adaptive myocardial remodelling.

Cardiac fibroblasts account for up to two-thirds of the total number of cells in the normal heart and are responsible for extracellular matrix homoeostasis. In vitro, type I collagen, the predominant myocardial collagen, stimulates proteolytic activation of constitutively secreted proMMP-2 (pro-matrix metalloproteinase-2). This occurs at the cell membrane and requires formation of a ternary complex with MT1-MMP (membrane-type-1 MMP) and TIMP-2 (tissue inhibitor of metalloproteinases-2). Following MI (myocardial infarction), normally quiescent fibroblasts initiate a wound healing response by transforming into a proliferative and invasive myofibroblast phenotype. Deprivation of oxygen to the myocardium is an inevitable consequence of MI; therefore this reparative event occurs under chronically hypoxic conditions. However, species and preparation variations can strongly influence fibroblast behaviour, which is an important consideration when selecting experimental models for provision of clinically useful information.

Diagnostic adequacy and accuracy of fine needle aspiration cytology in neck lump assessment: results from a regional cancer network over a one year period.

AIM: To establish the diagnostic accuracy and adequacy of fine needle aspiration cytology (FNAC) within a regional cancer network, and to determine what service improvements may be required to allow successful implementation of an FNAC-based, 'one-stop' head and neck clinic, as proposed by the current National Institute for Clinical Excellence guidelines. MATERIALS AND METHODS: The Sussex cancer network serves a population of 1,200,000 and contains five hospitals within three acute trusts. In 2004, an audit was undertaken retrospectively to examine the diagnostic adequacy and accuracy of head and neck FNAC across the network. Comparisons were then made with the results of subsequent relevant surgery. For the purposes of the audit, FNAC was subdivided into three main groups: salivary gland, thyroid gland and neck node. As part of the data analysis, we also noted the clinical source of the FNAC and whether it was performed blind or under image guidance. RESULTS: In 2004, 712 FNAC procedures were undertaken in 647 patients, 276 of whom underwent subsequent surgery. Fine needle aspiration cytology was non-diagnostic in 52 per cent of patients in the neck node group, in 50 per cent in the salivary gland group and in 30 per cent in the thyroid group. With these non-diagnostic results removed, statistical analysis was performed on data from those patients who had undergone both FNAC and subsequent surgery. This gave a sensitivity of 89 per cent and a specificity of 57 per cent in the neck node group, a sensitivity of 64 per cent and specificity of 100 per cent in the salivary gland group, and a sensitivity of 62 per cent and specificity of 86 per cent in the thyroid group. Diagnostic problems with FNAC were noted, particularly in the differentiation of reactive nodal hyperplasia from lymphoma and in diagnosing follicular thyroid lesions. Ultrasound guidance was used in 50 per cent of the thyroid FNAC procedures but in only a minority of patients in the neck node and salivary gland groups. CONCLUSION: This audit demonstrated widespread diagnostic difficulties associated with head and neck FNAC in a large patient sample. It is likely that these problems will be mirrored in other cancer networks. In order for one-stop head and neck clinics to succeed, the non-diagnostic rate of FNAC in particular must be minimised. There are strategies to enable this, depending on local resources, including increased access to cytologists or cytology technicians, diagnostic ultrasound, image guidance for FNAC and the use of ultrasound-guided core biopsy.

A decision support framework for sustainable urban water planning and management in new urban areas.

The paper discusses issues of decision support within the context of sustainable development and more specifically sustainable water cycle management to provide a context and a rationale for the decision support approach adopted within an on-going U.K. EPSRC-funded project, WaND. The paper proposes a set-up for a flexible, upgradeable, efficient and modular decision support framework and associated tools. Furthermore, the paper presents early prototypes of three decision support tools developed within the proposed framework including initial results for one of them.

Evaluation of a hypertension screening programme in Independence, Belize.

This study assesses the effectiveness of a hypertension-screening programme in Independence, Belize. Forty-nine of the 101 patients screened were found to have elevated blood pressure readings and were advised to seek medical care. Four months later, interviews with 35 of the 49 patients from the hypertensive group revealed that 85.7% of the patients had sought medical care. Women, elderly patients and patients with a previous history of hypertension were more likely than men, younger patients and those without a history of hypertension to seek follow-up medical care. The screening programme successfully directed a high proportion of patients with elevated blood pressure to seek appropriate medical care.

Motor neuron pathology in experimental autoimmune encephalomyelitis: studies in THY1-YFP transgenic mice.

Using adult male C57BL/6 mice that express a yellow fluorescent protein transgene in their motor neurons, we induced experimental autoimmune encephalomyelitis (EAE) by immunization with myelin oligodendrocyte glycoprotein peptide 35-55 (MOG peptide) in complete Freund's adjuvant (CFA). Control mice of the same transgenic strain received CFA without MOG peptide. Early in the course of their illness, the EAE mice showed lumbosacral spinal cord inflammation, demyelination and axonal fragmentation. By 14 weeks post-MOG peptide, these abnormalities were much less prominent, but the mice remained weak and, as in patients with progressive multiple sclerosis, spinal cord atrophy had developed. There was no significant loss of lumbar spinal cord motor neurons in the MOG peptide-EAE mice. However, early in the course of the illness, motor neuron dendrites were disrupted and motor neuron expression of hypophosphorylated neurofilament-H (hypoP-NF-H) immunoreactivity was diminished. By 14 weeks post-MOG peptide, hypoP-NF-H expression had returned to normal, but motor neuron dendritic abnormalities persisted and motor neuron perikaryal atrophy had appeared. We hypothesize that these motor neuron abnormalities contribute to weakness in this form of EAE and speculate that similar motor neuron abnormalities are present in patients with progressive multiple sclerosis.

Evaluation of a hypertension screening programme in Independence, Belize / Evaluación de Programa de Pesquizaje de la Hipertensión en Independencia, Belice

This study assesses the effectiveness of a hypertension-screening programme in Independence, Belize. Forty-nine of the 101 patients screened were found to have elevated blood pressure readings and were advised to seek medical care. Four months later, interviews with 35 of the 49 patients from the hypertensive group revealed that 85.7 of the patients had sought medical care. Women, elderly patients and patients with a previous history of hypertension were more likely than men, younger patients and those without a history of hypertension to seek follow-up medical care. The screening programme successfully directed a high proportion of patients with elevated blood pressure to seek appropriate medical care

Este estudio evalúa la efectividad de un programa de pesquizaje de la hipertensión en Independencia, Belice. Se halló que 49 de 101pacientes sometidos al pesquizaje produjeron lecturas de alta presión sanguínea y tensión arterial, y se les aconsejó buscar atención médica. Cuatro meses después, entrevistas con 35 de los 49 pacientes del grupo hipertenso revelaron que el 85.7% de los pacientes habían buscado atención médica. Las mujeres, los pacientes mayores y los pacientes con una historia previa de hipertensión presentaban una probabilidad mayor a buscar atención médica de seguimiento, que los hombres, los pacientes más jóvenes y aquéllos sin una historia de hipertensión. El programa de pesquizaje tuvo éxito en hacer que una alta proporción de pacientes con presión sanguínea alta buscaran adecuada atención médica.

Requesting organ donation: the case of self-efficacy--effects of the European Donor Hospital Education Programme (EDHEP).

One of the major reasons for the shortage of donor organs is the high number of refusals by relatives. Studies have shown that the quality of communication with bereaved relatives influences whether to object or agree to organ and/or tissue donation. Breaking news of brain stem death, approaching relatives for permission to donate organs while also appropriately managing emotional reactions of relatives are complex tasks, which require knowledge of the domains as well as adequate skills to communicate information and understanding. In this study the effect of the European Donor Hospital Education Programme (EDHEP) on the self-efficacy of Intensive Care staff is evaluated. Self-efficacy scores significantly improved after attending EDHEP; an effect that was maintained at six month follow-up. EDHEP participants with high baseline scores on self-efficacy, maintained the increase at follow-up. EDHEP participants with low baseline scores on self-efficacy showed the greatest increase at the post-test. Increases in self-efficacy were significantly related to decreases in the perceived difficulty of requesting. Experience had a significant effect on both self-efficacy beliefs and perceived difficulty of requesting donation. As self-efficacy beliefs are perceived as better predictors for future behaviour than prior attainments, the results call for further research in this domain. The data indicate that training programmes should be tailored not only to working circumstances of participants, but should also take levels of experience and self-efficacy into account. Further study is necessary and the best way to proceed is to relate the outcomes of this study to behavioural outcomes.

Remediating RDX-contaminated ground water with permanganate: laboratory investigations for the Pantex perched aquifer.

Ground water beneath the U.S. Department of Energy Pantex Plant is contaminated with the high explosive RDX (hexahydro-1,3,5-trinitro-1,3,5 triazine). The USDOE Innovative Treatment and Remediation Demonstration (ITRD) program identified in situ oxidation by permanganate as a technology fit for further investigation. We evaluated the efficacy of KMnO(4) to transform and mineralize RDX by determining degradation kinetics and carbon mass balances using (14)C-RDX. Aqueous RDX solutions (2-5 mg L(-1)) and RDX-contaminated slurries (50% solids, w/v) were treated with KMnO(4) at 1000, 2000, 4000, and 20000 mg L(-1). Treating an aqueous RDX solution of 2.8 mg L(-1) with 20000 mg KMnO(4) L(-1) decreased RDX to 0.1 mg L(-1) within 11 d while cumulative mineralization proceeded for 14 d until 87% of the labeled carbon was trapped as (14)CO(2). Similar cumulative mineralization was obtained when Pantex aquifer material was included in the solution matrix. Other experiments using 4000 mg KMnO(4) L(-1) showed that initial RDX concentrations (1.3-10.4 mg L(-1)) or initial pH (4-11) had little effect on reaction rates. Attempts to identify RDX degradates and reaction products showed that N(2)O was a product of permanganate oxidation and constituted 20 to 30% of the N balance. Time-course measurements of a (14)C-RDX solution treated with KMnO(4) revealed few (14)C-labeled degradates but through liquid chromatography-mass spectrometry (LC-MS) analysis, we present evidence that 4-nitro-2,4-diaza-butanol is formed. Aquifer microcosm studies confirmed that the transformation products not mineralized by KMnO(4) were much more biodegradable than parent RDX. These results indicate permanganate can effectively transform and mineralize RDX in the presence of aquifer material and support its use as an in situ chemical oxidation treatment for the Pantex perched aquifer.

Economic burden of pneumonia in an employed population.

OBJECTIVE: To estimate the overall economic burden of pneumonia from an employer perspective. METHODS: The annual, per capita cost of pneumonia was determined for beneficiaries of a major employer by analyzing medical, pharmaceutical, and disability claims data. The incremental costs of 4036 patients with a diagnosis of pneumonia identified in a health claims database of a national Fortune 100 company were compared with a 10% random sample of beneficiaries in the employer overall population. RESULTS: Total annual, per capita, employer costs were approximately 5 times higher for patients with pneumonia ($11 544) than among typical beneficiaries in the employer overall population ($2368). The increases in costs were for all components (eg, medical care, prescription drug, disability, and particularly for inpatient services). A small proportion (10%) of pneumonia patients (almost all of whom were hospitalized) accounted for most (59%) of the costs. CONCLUSIONS: Patients with pneumonia present an important financial burden to employers. These patients use more medical care services, particularly inpatient services, than the average beneficiary in the employer overall population. In addition to direct health care costs related to medical utilization and the use of prescription drugs, indirect costs due to disability and absenteeism also contribute to the high cost of pneumonia to an employer.

Modulation of gene expression by androgen and oestrogens in the testis and prostate of the adult rat following androgen withdrawal.

Androgens are important for the structural and functional integrity of the testis and the prostate and this may in part be mediated by the aromatisation of testosterone to oestradiol. The aim of the present study was to establish an in vivo model that would allow the identification of genes, the expression of which was regulated acutely by androgen and/or oestrogen in the male reproductive system. In rats in which the Leydig cells were ablated by administration of ethane dimethane sulfonate (EDS) 6 days earlier, testosterone esters (T) were administered from day 0 (To), and additional animals were administered either T, 17beta-oestradiol benzoate (EB) or diethylstilbestrol (DES) for 1 or 4 h on day 6 after EDS-treatment. Nuclear immunoexpression of the androgen receptor (AR) was reduced or absent from the testis but unaffected in the ventral prostate following these treatments. ERbeta immunoexpression in these tissues was unchanged. Northern blot analysis showed that EB and DES as well as T administration 4 h earlier could modulate mRNA expression of two androgen-responsive genes, C3 and SGP-2, in the prostate. The co-administration of T or EB with the AR antagonist, flutamide, or with the ER antagonist, ICI 182,780 (ICI), did not block the suppression of SGP-2 mRNA expression by T or EB. In contrast, the upregulation of C3 mRNA expression by T was successfully antagonised by both flutamide and by ICI. A preliminary evaluation of the expression of three Sertoli cell and five germ cell mRNAs revealed that their expression was not steroid regulated. Our results support the hypothesis that the action of testosterone in the male reproductive system may in part be mediated by its conversion to oestradiol. This in vivo model should prove of value in future studies to identify androgen and oestrogen regulated genes in the male reproductive system.

Gonadotropin-releasing hormone receptor in the teleost Haplochromis burtoni: structure, location, and function.

GnRH acts via GnRH receptors (GnRH-R) in the pituitary to cause the release of gonadotropins that regulate vertebrate reproduction. In the teleost fish, Haplochromis burtoni, reproduction is socially regulated through the hypothalamus-pituitary-gonadal axis, making the pituitary GnRH-R a likely site of action for this control. As a first step toward understanding the role of GnRH-R in the social control of reproduction, we cloned and sequenced candidate GnRH-R complementary DNAs from H. burtoni tissue. We isolated a complementary DNA that predicts a peptide encoding a G protein-coupled receptor that shows highest overall identity to other fish type I GnRH-R (goldfish IA and IB and African catfish). Functional testing of the expressed protein in vitro confirmed high affinity binding of multiple forms of GNRH: Localization of GnRH-R messenger RNA using RT-PCR revealed that it is widely distributed in the brain and retina as well as elsewhere in the body. Taken together, these data suggest that this H. burtoni GnRH receptor probably interacts in vivo with all three forms of GNRH:

Integration of cytogenetic landmarks into the draft sequence of the human genome.

We have placed 7,600 cytogenetically defined landmarks on the draft sequence of the human genome to help with the characterization of genes altered by gross chromosomal aberrations that cause human disease. The landmarks are large-insert clones mapped to chromosome bands by fluorescence in situ hybridization. Each clone contains a sequence tag that is positioned on the genomic sequence. This genome-wide set of sequence-anchored clones allows structural and functional analyses of the genome. This resource represents the first comprehensive integration of cytogenetic, radiation hybrid, linkage and sequence maps of the human genome; provides an independent validation of the sequence map and framework for contig order and orientation; surveys the genome for large-scale duplications, which are likely to require special attention during sequence assembly; and allows a stringent assessment of sequence differences between the dark and light bands of chromosomes. It also provides insight into large-scale chromatin structure and the evolution of chromosomes and gene families and will accelerate our understanding of the molecular bases of human disease and cancer.

GenMapDB: a database of mapped human BAC clones.

GenMapDB (http://genomics.med.upenn.edu/genmapdb) is a repository of human bacterial artificial chromosome (BAC) clones mapped by our laboratory to sequence-tagged site markers. Currently, GenMapDB contains over 3000 mapped clones that span 19 chromosomes, chromosomes 2, 4, 5, 9-22, X and Y. This database provides positional information about human BAC clones from the RPCI-11 human male BAC library. It also contains restriction fragment analysis data and end sequences of the clones. GenMapDB is freely available to the public. The main purpose of GenMapDB is to organize the mapping data and to allow the research community to search for mapped BAC clones that can be used in gene mapping studies and chromosomal mutation analysis projects.

Comparative effects of neonatal exposure of male rats to potent and weak (environmental) estrogens on spermatogenesis at puberty and the relationship to adult testis size and fertility: evidence for stimulatory effects of low estrogen levels.

This study investigated whether neonatal exposure of male rats to estrogenic compounds altered pubertal spermatogenesis (days 18 and 25) and whether the changes observed resulted in long-term changes in testis size, mating, or fertility (days 90-100). Rats were treated neonatally with a range of doses (0.01-10 microg) of diethylstilbestrol (DES; administered on alternate days from days 2-12), a high dose of octylphenol (OP; 2 mg administered daily from days 2-12) or bisphenol A (Bis-A; 0.5 mg administered daily from days 2-12), or vehicle, while maintained on a standard soy-containing diet. The effect on the same parameters of rearing control animals on a soy-free diet was also assessed as was the effect of administering such animals genistein (4 mg/kg/day daily from days 2-18). Testis weight, seminiferous tubule lumen formation, the germ cell apoptotic index (apoptotic/viable germ cell nuclear volume), and spermatocyte nuclear volume per unit Sertoli cell nuclear volume were used to characterize pubertal spermatogenesis. Compared with (soy-fed) controls, DES administration caused dose-dependent retardation of pubertal spermatogenesis on day 18, as evidenced by decreases in testis weight, lumen formation, and spermatocyte nuclear volume per unit Sertoli cell and elevation of the germ cell apoptotic index. However, the two lowest doses of DES (0.1 and 0.01 microg) significantly increased spermatocyte nuclear volume per unit Sertoli cell. Similarly, treatment with either OP or Bis-A significantly advanced this and some of the other aspects of pubertal spermatogenesis. Maintenance of control animals on a soy-free diet also significantly advanced lumen formation and spermatocyte nuclear volume per unit Sertoli cell compared with controls fed a soy-containing diet. Administration of genistein reversed the stimulatory effects of a soy-free diet and significantly retarded most measures of pubertal spermatogenesis. In general, plasma FSH levels in the treatment groups changed in parallel to the spermatogenic changes (reduced when pubertal spermatogenesis retarded, increased when pubertal spermatogenesis advanced). By day 25, although the changes in FSH levels largely persisted, all of the stimulatory effects on spermatogenesis seen on day 18 in the various treatment groups were no longer evident. In adulthood, testis weight was decreased dose dependently in rats treated neonatally with DES, but only the lowest dose group (0.01 microg) showed evidence of mating (3 of 6) and normal fertility (3 litters). Animals treated neonatally with OP or Bis-A had normal or increased (Bis-A) testis weights and exhibited reasonably normal mating/fertility. Animals fed a soy-free diet had significantly larger testes than controls fed a soy-containing diet, and this difference was confirmed in a much larger study of more than 24 litters, which also showed a significant decrease in plasma FSH levels and a significant increase in body weight in the males kept on a soy-free diet. Neonatal treatment with genistein did not alter adult testis weight, and although most males exhibited normal mating and fertility, a minority did not mate or were infertile. It is concluded that 1) neonatal exposure of rats to low levels of estrogens can advance the first wave of spermatogenesis at puberty, although it is unclear whether this is due to direct effects of the estrogen or to associated elevation of FSH levels; 2) the effect of high doses of OP and Bis-A on these processes is essentially benign; and 3) the presence or absence of soy or genistein in the diet has significant short-term (pubertal spermatogenesis) and long-term (body weight, testis size, FSH levels, and possibly mating) effects on males.

Screening for cognitive impairment in older African-Caribbeans.

BACKGROUND: There are increasing numbers of older African-Caribbeans in the United Kingdom. Screening instruments are commonly used in the detection of cognitive impairment, but have not been assessed within this population. This study aimed to develop culturally modified versions of screening instruments for cognitive impairment (Mini-Mental State Examination (MMSE) and Abbreviated Mental Test (AMT)) and to determine their sensitivity and specificity in the diagnosis of dementia. METHODS: The instruments were modified using a process involving a community group of African-Caribbeans and an academic group of health professionals. They were used in a two-stage study involving community resident African-Caribbeans aged 60 years or over in inner-city Manchester, comparing the screening instruments against a computerized diagnostic interview. RESULTS: One hundred and thirty people completed the study. The results for the largest subgroup, the Jamaicans (N = 96) were analysed. Effects of gender, age and education on the MMSE and AMT scores were evaluated. The correlations between the screening instruments and diagnostic interview were highly significant (P < 0.001). At appropriate cut-offs both screening instruments demonstrated high sensitivity and acceptable specificity levels. CONCLUSIONS: A defined process with lay input has assisted in producing culturally modified versions of the MMSE and AMT that perform well compared with a diagnostic interview, if an appropriate cut-off is used. They are easy to administer and acceptable to older African-Caribbean people. The results need to be viewed within the limitations of the current study.

The European Donor Hospital Education Programme (EDHEP): enhancing communication skills with bereaved relatives.

Intensive care medical and nursing staff self-rate their communication skills as improved following attendance at the European Donor Hospital Education Programme (EDHEP) workshop. A prospective study was conducted to determine what impact EDHEP has on communication skills. Doctor-nurse pairs from 10 experimental and 10 control Intensive Care Units undertook two standardized simulated relative encounters (Breaking Bad News and Donation Request) at three measurement points (pre, post and follow-up). Nurses showed no change in communication skills. Experimental group doctors showed significant improvement in breaking bad news and requesting donation; most of these improvements were not maintained. Control group doctors showed some improvement in breaking bad news, indicating that participating in measurement by itself initiates some transient change in communication skills. Attendance at EDHEP does lead to significant improvement in some, but not all, communication skills essential in breaking bad news and requesting donation. Further research is necessary to determine what factors additional to EDHEP will contribute to enduring change in these particular skills.

Effect of chronic administration of an aromatase inhibitor to adult male rats on pituitary and testicular function and fertility.

The aim of the present study was to evaluate the effects of the administration of a potent non-steroidal aromatase inhibitor, anastrozole, on male reproductive function in adult rats. As anastrozole was to be administered via the drinking water, a preliminary study was undertaken in female rats and showed that this route of administration was effective in causing a major decrease in uterine weight (P<0.02). In an initial study in male adult rats, anastrozole (100 mg/l or 400 mg/l) was administered via the drinking water for a period of 9 weeks. Treatment with either dose resulted in a significant increase ( approximately 10%) in testis weight and increase in plasma FSH concentrations (P<0.01) throughout the 9 weeks. Mating was altered in both groups of anastrozole-treated rats, as they failed to produce copulatory plugs. Histological evaluation of the testes from anastrozole-treated rats revealed that spermatogenesis was grossly normal. In a more detailed study, adult rats were treated with 200 mg/l anastrozole via the drinking water for periods ranging from 2 weeks to 1 year. Plasma FSH and testosterone concentrations were increased significantly (P<0.001) during the first 19 weeks of treatment. However, LH concentrations were increased only at 19 weeks (P<0.001) in anastrozole-treated rats, and this coincided with a further increase in circulating and intratesticular testosterone concentrations (P<0.05). No consistent change in inhibin-B concentrations was observed during the study. Suppression of plasma oestradiol concentrations could not be demonstrated in anastrozole-treated animals, but oestradiol concentrations in testicular interstitial fluid were reduced by 18% (P<0.01). Mating was again inhibited by anastrozole treatment, but could be restored by s.c. injection of oestrogen, enabling demonstration that rats treated for 10 weeks or 9 months were still fertile. Testis weight was increased by 19% and 6% after treatment for 19 weeks and 1 year, respectively. Body weight was significantly decreased (P<0.01) by 19 weeks of anastrozole treatment; after 1 year the animals appeared to have less fat as indicated by a 27% decrease in the weight of the gonadal fat pad. The majority of anastrozole-treated animals had testes with normal spermatogenesis but, occasionally, seminiferous tubules showed abnormal loss of germ cells or contained only Sertoli cells. Ten percent of anastrozole-treated animals had testes that appeared to contain only Sertoli cells, and one rat had 'giant' testes in which the tubule lumens were severely dilated. Morphometric analysis of the normal testes at 19 weeks showed no difference in the number of Sertoli cells or germ cells, or the percentage volumes of the seminiferous epithelium, tubule lumens and interstitium between control and anastrozole-treated rats. On the basis of the present findings, oestrogen appears to be involved in the regulation of FSH secretion and testosterone production, and is also essential for normal mating behaviour in male rats. Furthermore, these data suggest that the brain and the hypothalamo-pituitary axis are considerably more susceptible than is the testis to the effects of an aromatase inhibitor. Anastrozole treatment has resulted in a model of brain oestrogen insufficiency.