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In this study, the authors developed HEK293 cell lines that stably coexpressed optimal amounts of beta-arrestin2-Rluc and VENUS fusions of G protein-coupled receptors (GPCRs) belonging to both class A and class B receptors, which include receptors that interact transiently or stably with beta-arrestins. This allowed the use of a bioluminescence resonance energy transfer (BRET) 1- beta-arrestin2 translocation assay to quantify receptor activation or inhibition. One of the developed cell lines coexpressing CCR5-VENUS and beta-arrestin2- Renilla luciferase was then used for high-throughput screening (HTS) for antagonists of the chemokine receptor CCR5, the primary co-receptor for HIV. A total of 26,000 compounds were screened for inhibition of the agonist-promoted beta-arrestin2 recruitment to CCR5, and 12 compounds were found to specifically inhibit the agonist-induced beta-arrestin2 recruitment to CCR5. Three of the potential hits were further tested using other functional assays, and their abilities to inhibit CCR5 agonist-promoted signaling were confirmed. This is the 1st study describing a BRET1-beta-arrestin recruitment assay in stable mammalian cells and its successful application in HTS for GPCRs antagonists.

Objectives: Physical activity can prevent or retard the loss of muscle mass associated with aging. On the other hand, it has been suggested that HRT may also help prevent sarcopenia in postmenopausal women. We thus examined if HRT provides additional beneficial effect in physically active postmenopausal women., Methods: Forty postmenopausal women aged between 55 and 65 years old (normal weight, healthy and no medication) were recruited. Seventeen women were already taking HRT for at least one year whereas 23 were never submitted to HRT. Body composition was measured by DXA and physical activity metabolism was obtained by the use of accelerometry. Subjects were divided in tertile groups based on their daily physical activity energy expenditure (PAEE)., Results: Physical activity groups were similar for age, HRT users distribution, BMI, trunk fat-free mass (FFM), and all fat mass (FM) components. The group of women who were the most physically active significantly displayed greater total FFM, appendicular FFM, and muscle mass index (MMI) compared to the group of less active women (P < 0.05) whereas HRT added no additional effect on any FFM components., Conclusions: Our results suggest that in active postmenopausal women, HRT does not provide any additional beneficial effect on body composition.

Although hepatocyte transplantation is a promising therapy for acute liver failure in human, there is still a lack of animal models suffering from hepatic injury in which the benefits of hepatocyte transplantation could be evaluated solely, without the bias caused by immunosuppression. As a consequence, the aim of the study was first to develop reproducible models of partial hepatectomy and of thioacetamide (TA)- or Jo2-induced acute liver failure in nude mice. Chronic liver disease was also investigated by repeated injections of sublethal doses of thioacetamide. Survival rates, routine histologic observations, alanin aminotransferase sera content, Ki67, and caspase 3 immunodetection were investigated both after 40% partial hepatectomy and after toxic-induced damages. Liver injuries were more severe and/or precocious in nude mice than in Balb/c mice for a given treatment with a maximum of acute injury obtained 24 h after single toxic injection, and were found to be transitory and reversible within 10 days. Toxics induced apoptosis followed by necrosis, confirming recent published data. Onset of fibrosis leading to reproducible chronic cirrhosis in nude mice correlated with increasing number of Ki67-positive cells, indicating that high levels of cell proliferation occurred. Chronic cirrhosis progressively reversed to fibrosis when the treatment ceased. Preliminary results demonstrated that engrafted xenogeneic hepatocytes could be detected in the host liver by anti-MHC class I immunohistochemistry. Fractions enriched in 2n or 4n hepatocytes by cell sorting using a flow cytometer were equivalent to the unpurified fraction in terms of engraftment in control nude mice or in nude mice subjected to PH. However, in mice suffering from liver injury 24 h after Jo2 or TA treatment, the engraftment of 2n hepatocytes was about twice that of an unpurified hepatocyte population or of a population enriched in 4n hepatocytes.

The purpose of this descriptive study was to assess the impact of limited resources on the practice of dialysis in Quebec and to highlight certain ethical issues. Twelve semi-structured interviews were done with nurses in charge of 14 dialysis centres in Quebec. A survey using self-administered questionnaires was also carried out between January 2000 and July 2001, with a convenience sample of 412 patients and 156 other persons involved, including 116 dialysis nurses. Two discussion groups brought together sixteen stakeholders from four dialysis centres. The results presented here were obtained by triangulating methods and data. They show that access to dialysis is not limited by Quebec nephrologists, that patients are increasingly old and sick, that teams are working to the utmost of their ability and that it is difficult for nursing staff to provide optimal care under these conditions.

Hepatic resection (HR) is the treatment of choice for small hepatocellular carcinoma (HCC) in a noncirrhotic liver, whereas liver transplantation (LT) offers better results in patients with impaired hepatic function (Child B and C). However, it is still debated whether HR or LT is the best strategy for patients with Child A cirrhosis. We conducted a retrospective study on 37 consecutive patients with Child A cirrhosis and small HCC, treated between 1991 and 1999. Seventeen of these patients, who underwent LT, were compared with 20 patients who underwent HR, and prognostic factors for survival and tumor recurrence were analyzed. The primary endpoints were the intention-to-treat, 3- and 5-year survival, and 3- and 5-year recurrence-free survival. Three- and 5-year patient survival rate both were significantly (P =.04) higher in the LT group (87% and 71%, respectively) than in the HR group (67 and 36% respectively). Similarly, the 3- and 5- year recurrence-free survival rates were 87% and 80% for the LT group, and 52% and 40% for the HR group (P =.03). Absence of microscopic vascular invasion was the only other prognostic factor correlated with significantly better recurrence-free survival (P =.02). Therefore, we concluded that in patients with Child A cirrhosis and small HCC, liver transplantation resulted in better overall and disease-free survival than HR.

Background: FTY720 is a novel immunomodulator with a unique mechanism of action, i.e. chemokine-dependent lymphocyte homing into secondary lymphoid organs associated with profound lymphocyte depletion in blood. We investigated its efficacy, either FTY720 alone or together with cyclosporine or the rapamycin derivative rapamycin derivative (RAD), in cynomolgus monkey kidney allotransplantation., Methods: Life-supporting allotransplantation was performed in bilaterally nephrectomized hosts. Compounds were given once daily by oral gavage. Monitoring was done by serum creatinine and urea, and rejection was concluded when values exceeded 500 micromol/L and 50 mmol/L, respectively (5-6 times the upper limit of reference values). Rejection was confirmed by graft histology. The termination point was set to 100 days after transplantation. In addition, animals were monitored for 24 hr drug concentrations and thorough inspection of potential adverse side effects., Results: FTY720 given alone at 3.0 mg/kg per day prolonged rejection-free survival (33-85 days, mean 24 hr concentration between 54 and 66 ng/mL [n=3]), but it was not efficacious at a 0.3 mg/kg per day dose. For cyclosporine alone, 30 mg/kg per day during maintenance was efficacious (average concentration above 100 ng/mL, historical data from our group), and for RAD alone 0.75 mg/kg per day (concentration above 10 ng/mL). Efficacious FTY720-cyclosporine-A (CsA) or FTY720-RAD combinations were established using 0.1-0.3 mg/kg per day FTY720, 10-30 mg/kg per day cyclosporine, and/or 0.25-0.50 mg/kg per day RAD. Compared with single-compound treatment, FTY720 effective doses and 24 hr trough concentrations were at least tenfold lower in combination treatment and those of cyclosporine and RAD about twofold lower, indicative of effective synergy between the compounds. Already at the lowest FTY720 dose tested (0.03 mg/kg per day), there was a profound lymphocyte depletion down to about 30% of pretransplant values, which further increased at the highest dose (3.0 mg/kg per day, to about 14% of pretransplant values). Lymphocyte depletion was reflected by a decrease in T and B subpopulations., Conclusion: FTY720 is an effective immunosuppressant in prevention of acute kidney allograft rejection in cynomolgus monkeys and synergizes with cyclosporine and/or RAD in yielding rejection-free allograft survival.

Background: Auxiliary partial orthotopic liver transplantation (APOLT) has been developed in order to benefit from the efficacy of orthotopic liver transplantation (OLT) in the treatment of fulminant hepatic failure (FHF), but to avoid the negative counterpart of OLT which is to eliminate the possibility of native liver (NL) regeneration and which consequently implies a life-long immunosuppression., Methods: In our institution we performed 16 consecutive APOLTs in 15 patients between October 1992 and December 1999. Patients' mean age was 30 years (range 0.5-65 years). The causes of FHF were viral (HAV = 3; HBV = 3), drugs (n = 4), or others (n = 5). None of the patients had a history of chronic liver disease. The decision to transplant was taken when the patients met well-defined criteria. All but one of the patients were in a coma., Results: Five patients died, 10 patients are alive (66.7%). Regeneration of the NL occurred in 11 of the 15 patients (73.3%) and in 8 of the 10 survivors. Six of these 8 patients have permanently stopped immunosuppressive therapy. These results can be favorably compared with those of OLT for FHF. In the European Transplant Registry, the survival rate is 57% at 5 years (2612 patients receiving OLT for FHF between 1988 and 1998). In our experience the survival rate is 59% at 5 years (42 patients receiving OLT for FHF between 1987 and 1999)., Conclusions: APOLT is feasible in both adults and children; it rapidly restored liver function and reversed encephalopathy. Right APOLT seems more advisable since the right liver provides more functional hepatocytes; however, left APOLT harvested in an adult appears sufficient for a child. APOLT should be proposed only to patients with high chances of liver regeneration: age of recipient, etiology of liver failure, interval between onset of jaundice and occurrence of encephalopathy, and quality of liver graft are early prognostic indicators. Better results have been observed with younger patients (less than 40 years old) presenting with FHF (rather than subfulminant hepatic failure (SHF)) and due to HAV, HBV, or paracetamol.

Background: In a pig liver transplantation model, we compared the effects of Celsior solution (CS), an extracellular preservation solution, with Viaspan (University of Wisconsin solution, UW) on graft function and animal survival., Methods: Pig livers were flushed with either CS or UW solution and cold-stored for 12 hr (group 1) or for 8 to 10 hr (group 2). Grafts were transplanted orthotopically. Intrahepatic reduced and oxidized glutathione and adenine nucleotides were evaluated 1 hr after reperfusion. Liver function of transplanted animals was monitored for up to 6 days by serum transaminases, total bilirubin, purine nucleoside phosphorylase, and prothrombin levels., Results: In group 1, all animals died within 24 hr after reperfusion regardless of the preservation solution used. In group 2, no significant difference was seen in survival between the CS (72%) and the UW (67%) groups 6 days after transplantation, and there were no statistically significant differences in the biochemical data. There were no differences in histological evaluation of the livers at the time of death or killing of the animals between the CS and UW groups., Conclusion: Within the limits of this pilot study, CS is equivalent to UW in terms of graft function and animal survival.

Purpose: The purpose of this study was to describe the findings of serial ultrasound investigations of functioning and histologically normal renal allografts in the cynomolgus monkey., Methods: Ten cyclosporine (Neoral) treated cynomolgus monkeys underwent renal allograft transplantation with bilateral nephrectomy, seven of which were examined serially with ultrasound. Ultrasound findings were compared to serum creatinine, and the results of histology from allograft biopsy on day 150 post-transplantation., Results: Allografts increased in volume up to one and a half to twice that of their original volume and appeared morphologically similar to native kidneys. Allograft ureters were dilated postoperatively but decreased in size with time. Other than in two cases of ureter complications, the resistive index (RI) was normal in functioning grafts., Conclusions: Elevations in RI, as well as graft enlargement and increased cortical thickness, were related to graft pathology, but not necessarily to rejection histologically. The ultrasound findings of functioning grafts and of surgical complications after renal allograft transplantation in the cynomolgus monkey were similar to those in humans.

Banking of cryopreserved hepatocytes is a prerequisite for large-scale hepatocyte transplantation in the clinic. We compared the efficacy of intrasplenic transplantation into Nagase analbuminemic rats (NAR) of freshly isolated (FIH) and cryopreserved (CH) hepatocytes. Hepatocytes were cryopreserved using a controlled rate freezing protocol. Albumin production of thawed CH and FIH was measured in vitro in culture by ELISA and by Western blot. After in vivo intrasplenic transplantation of NAR with either FIH or CH we assessed 1) albumin in the serum of recipients by ELISA and by Western blotting analysis at different time intervals, and 2) hepatocyte engraftment by albumin immunohistochemical staining into spleens and livers at euthanasia. In vitro, albumin was produced up to day 4 of culture in both CH and FIH. In vivo, no intrasplenic engraftment of hepatocytes occurred. Intrahepatic engraftment of CH (cell number/mm2) was significantly (twofold) lower than that of FIH and appeared only as isolated cells and small (<10 cells) clusters, while bigger clusters (>10 cells) were observed with FIH. In the FIH group, serum albumin production was observed up to 32-49 days posttransplantation while in the CH group no serum albumin production was detected. Our results emphasize the need to improve 1) hepatocyte transplantation procedures either by repeated hepatocytes injections and/or by transplantation under a regeneration response, and 2) the freeze/thaw protocols of hepatocytes.

Background: Production of transgenic pigs for multiple transgenes is part of a potential strategy to prevent immunological events involved in xenograft rejection. Use of a genetically engineerable rodent as a donor in primates could allow testing in vivo of the effects of different transgenes on controlling xenograft rejection. As a first step in the development of a donor containing multiple transgenes, transgenic rats for human decay-accelerating factor (DAF) were used as heart donors to test their resistance against complement (C)-mediated rejection by non-human primates., Materials and Methods: Transgenic rats were generated by using a construct containing the human DAF cDNA under the transcriptional control of the endothelial cell (EC)-specific human ICAM-2 promoter. DAF expression was evaluated by immunohistology and by FACS analysis of purified ECs. Resistance of transgenic hearts against C-mediated damage was evaluated by ex vivo perfusion with human serum and by transplantation into cynomolgus monkeys., Results: Immunohistological analysis of DAF expression in several organs from two transgenic lines showed uniform expression on the endothelium of all blood vessels. ECs purified from transgenic hearts showed 50% DAF expression compared to human ECs and >70% reduction of C-dependent cell lysis compared to control rat ECs. Hemizygous transgenic hearts perfused with human serum showed normal function for >60 min vs. 11. 2 +/- 1.7 min in controls. Hemi- or homozygous transgenic hearts transplanted into cynomolgus monkeys showed longer survival (15.2 +/- 7 min and >4.5 hr, respectively) than controls (5.5 +/- 1.4 min). In contrast to hyperacutely rejected control hearts, rejected homozygous DAF hearts showed signs of acute vascular rejection (AVR) characterized by edema, hemorrhage, and an intense PMN infiltration., Conclusions: We demonstrate that endothelial-specific DAF expression increased heart transplant survival in a rat-to-primate model of xenotransplantation. This will aid in the analysis of AVR and of new genes that may inhibit this form of rejection, thus helping to define strategies for the production of transgenic pigs.

It has been well-documented that the clinical experience is one of the most anxiety-producing aspects of nursing education. When feelings of anxiety become severe, they present a clear threat to the student's success in the program. This article explores the role of "caring" in nursing education as a means of reducing student anxiety. Caring, described at length by Jean Watson, has become one of the most popular trends in the education of young nurses. When caring behaviors are demonstrated in a meaningful way by clinical instructors, the student may experience a sense of comfort and belonging, which may in turn be effective in reducing anxiety and enabling the student to successfully complete a clinical rotation. The aim of this article is to inspire nurses, not only those in the educational setting but in all settings and at all levels of their careers, to reconsider the effects and benefits of displaying a caring attitude.

The accumulation of lysosomal bodies has long been considered to be an important correlate of aging. However it is not well established whether these age related changes interfere with cellular function. In this study, an evaluation of lysosomes by ultrastructural analysis was performed in livers of 4-6 and 20-24-month-old Sprague-Dawley female rats, fed ad libitum (A) or a restricted diet (R). An attempt was made to relate this parameter to hepatic protein synthesis, a liver function known to decrease with age and increase with dietary restriction. Aging was accompanied in both A and R animals with higher number and size of secondary lysosomes (lipofuscin) and by a decrease in total protein synthesis in hepatocytes. When compared to age matched ad libitum fed animals, livers of food restricted rats contained higher number of secondary lysosomes, yet exhibited higher protein synthetic capacity. Thus in hepatocytes, lipofuscin accumulation does not seem to interfere with cellular function.

Hepatic drug metabolism was investigated in female Sprague-Dawley rats fed ad libitum (A) or a restricted diet (R) (implemented from age 1 month), at 1.5, 4.5 and 12 months to determine the short- and long-term effects of caloric restriction. Microsomal cytochrome P-450 content and NADPH cytochrome c reductase activity were not modified by age. While dietary restriction did not affect cytochrome P-450, it significantly increased NADPH cytochrome c reductase activity at all time periods when compared to corresponding A-fed groups. Aniline hydroxylase and aminopyrine N-demethylase activity tended to decrease with age in the A-fed groups but the differences did not prove to be statistically significant. A significant decrease of aminopyrine N-demethylase was observed with age in R rats. A significant reduction of aniline hydroxylase activity was noted in the R groups compared to age-matched A-fed controls. In contrast, aminopyrine N-demethylase activity increased significantly, but only at 1.5 months of age. Glutathione S-transferase activity was augmented between 1.5 and 4.5 months of age, and this was followed by a significant decrease at age 12 months in both A and R groups. Dietary restriction had no effect on this enzymatic activity. The microsomal cholesterol and phospholipid content as well as the cholesterol/phospholipid molar ratio changed significantly between 1.5 and 4.5 months of age but not between 4.5 and 12 months of age. These parameters were unaltered by dietary restriction. In conclusion, in the female Sprague-Dawley rat there are no statistically significant changes in hepatic microsomal components and drug metabolizing capacity between 1.5 and 12 months of age. Dietary restriction resulted in significant changes in enzymes related to drug metabolism which varied with the enzyme examined. In general, these changes were similar after short- or long-term dietary intervention.

The specific activity of 4 lysosomal enzymes was studied in homogenate, hepatocytes, Kupffer and endothelial cells isolated from the livers of female Sprague-Dawley rats aged 3.5, 12 and 24 months. Cells were obtained by enzymatic digestion and centrifugal elutriation. Cell viability was not affected by age or diet. In hepatocytes, the activities of all enzymes (acid phosphatase, beta-galactosidase, arylsulfatase B and cathepsin D) increased with age in rats fed ad libitum (A) but were not altered significantly by dietary restriction. The activities of all enzymes except acid phosphatase were systematically higher at 3.5 months of age in Kupffer and endothelial cells than in hepatocytes. Acid phosphatase, arylsulfatase B and cathepsin D activities increased with age in both Kupffer and endothelial cells. Beta galactosidase was decreased significantly with age in Kupffer cells but was elevated in endothelial cells. Rats exposed to dietary restriction (R) showed higher activities of beta-galactosidase, arylsulfatase B and cathepsin D when compared to corresponding A animals with the exception of the younger age group. No clear cut pattern was observed in acid phosphatase activity. Thus, the activities of liver lysosomal enzymes increase with age but the pattern of change differs with respect to enzyme and cell populations. The heightened enzyme activity in Kupffer and endothelial cells from R rats may reflect a more efficient phagocytic capacity in these animals.

Treatment of adolescents with cerebral palsy often presents clinical problems that differ from those encountered when treating younger children with cerebral palsy. Muscle contractures, which may not yield to traditional therapeutic exercise, may be a problem. The purpose of this case report is to describe the use of serial casting in the treatment of knee joint flexion contractures in an adolescent with cerebral palsy.

The regional and laminar distribution of the noradrenaline (NA) innervation in the adult rat cerebral cortex was quantified in radioautographs of semithin sections from whole hemisphere slices incubated with tritiated catecholamines and a monoamine oxidase inhibitor. Uptake-labeled axonal varicosities (aggregates of silver grains) were counted with the help of a computerized image analyzer in seven cytoarchitectonic areas of the rostral half of the cortex: Cg3, rostral AID, Cg2, Fr1, Par1, caudal AID, and Pir (prepiriform) according to Zilles's nomenclature. Both dopamine (DA) and NA terminals were detected after incubation with [3H]DA and citalopram or with [3H]NA alone. In the presence of desipramine (DMI), DA terminals alone were demonstrated; the number of NA terminals was then obtained by subtraction from counts in adjacent slices incubated with or without DMI. These counts suggested that DA and NA varicosities were fully visualized only after labeling with their respective tritiated amine. Similar numbers of labeled NA varicosities as inferred after [3H]NA incubation with or without DMI were observed after [3H]NA incubation in the presence of benztropine (BZ). This indicated that NA terminals were then maximally detected to the exclusion of the DA ones, and the latter approach was adopted for the acquisition of normative data. Since the average diameter of the labeled NA varicosities was known from earlier measurements in electron microscope radioautographs, the initial counts of labeled sites/mm2 of histological section could be expressed as numbers of varicosities/mm3 of tissue following a double correction for incomplete detection at the chosen duration of radioautographic exposure and section thickness. The overall density of NA innervation was thus estimated at 1.2 million varicosities/mm3 of tissue, with no statistically significant differences between the seven cortical areas examined. In every region, the number of NA terminals was the greatest in the molecular layer (1.5-2 times the density in the rest of cortex) and then progressively decreased in the underlying cortex, with a two- to threefold difference between upper and lower layers. These numerical data allowed an estimation to be made of the possible number of cortical NA varicosities per locus coeruleus nerve cell body of origin (at least 300,000), of their average number per cortical neuron (30-50), their actual incidence among all terminals in the cortex (1/1,000), their mean endogenous amine content per varicosity (0.22 fg), and the mean number of recognition sites for the uptake blocker DMI (4,500/varicosity).(ABSTRACT TRUNCATED AT 400 WORDS)

Conditions leading to selective and complete labeling of the noradrenaline (NA) and serotonin (5-HT) innervations in rat cerebral cortex were sought by incubating 200-micron-thick whole hemisphere slices with various combinations of tritiated monoamines and uptake blockers at different concentrations in the presence of a monoamine oxidase inhibitor. After fixation with glutaraldehyde, post-fixation with osmium tetroxide and flat-embedding in Epon, 4-micron-thick sections of the entire slices were radioautographed by dipping in nuclear emulsion. As previously reported, dopamine (DA) terminals could be specifically visualized and counted following incubation with 1 micron [3H]DA and 5 microM desipramine (DMI) with or without 5 microM citalopram (CITAL). The number of NA terminals could thus be obtained by subtracting DA varicosities from the total number of sites labeled in adjacent slices incubated without DMI but in presence of CITAL to eliminate some interspecific labeling of 5-HT terminals. NA terminals could also be identified exclusively and counted after labeling with 1 microM [3H]NA in the presence of 10 microM benztropine. 5-HT terminals were specifically detected after incubation with 1 microM [3H]5-HT in the presence of 10 microM non-radioactive NA. The labeled varicosities were counted in areas FR1 and PAR1 of the frontal and the parietal neocortex, respectively, with the aid of a microcomputer-based image analysis system. DA varicosities were concentrated mainly in layer VI of these regions and were more numerous in the frontal than the parietal area. NA terminals were equally distributed in the two regions but approximately twice as numerous in layer I than subjacent layers. The 5-HT innervation also showed a comparable overall density in the two cortical regions but with a differing intracortical distribution. In the frontal area, 5-HT terminals were slightly more concentrated in layer I (1.3-fold) than underlying layers where they were rather uniformly distributed. In the parietal area, layer I was again the most densely innervated (1.8 times the average), but a second zone of higher density (1.5 times average) was present in the outer part of layer V. The remaining layers showed lower numbers of 5-HT terminals than in the frontal region. To obtain absolute estimates of these innervation densities, the number of detected varicosities was assessed experimentally as a function of radioautographic exposure time and of histological section thickness, and their 'equivalent circle diameter' was measured in electron microscope radioautographs.(ABSTRACT TRUNCATED AT 400 WORDS)

The regional and laminar distribution of the serotonin (5-HT) innervation in adult rat cerebral cortex was quantified in radioautographs of semi-thin sections from whole hemisphere slices incubated with tritiated 5-HT and a monoamine oxidase inhibitor. Uptake-labelled axonal varicosities (aggregates of silver grains) were counted with the help of a computerized image analyser, in seven cytoarchitectonic areas of the anterior half of the cortex: Cg3, rostral AID, Cg2, Fr1, Par1, caudal AID and Pir (prepiriform). Since the average diameter of cortical 5-HT varicosities had been previously measured in electron microscope radioautographs, the counts of labelled sites per mm2 of radioautograph could be transformed to numbers of varicosities per mm3 of tissue after a double correction for incomplete detection at the chosen duration of radioautographic exposure and from the thickness of section examined. The mean regional density of cortical 5-HT innervation was thus evaluated at 5.8 million varicosities per mm3 of tissue, ranging from 4.4 (Cg2) to 7.1 million (AIDr). Cg2, Par1 and Fr1 showed significantly lower regional densities than Cg3, AIDc, Pir and AIDr. The highest laminar density was that of layer I in all regions except Pir, but each region had a distinct pattern of 5-HT innervation. In Par1, for example, there was a second band of predilection amounting to 5.3 million varicosities per mm3 at the height of layer Va. On the basis of these figures, it was possible to extrapolate the average number of cortical 5-HT varicosities per midbrain raphe nerve cell body of origin (500,000 at least), their average number per cortical target neuron (145-230), their incidence among all axon terminals in cortex (1/200), their mean endogenous amine content (0.045 fg), and their mean number per varicosity of recognition sites for reuptake blockers such as paroxetine, citalopram or cyanoimipramine (5000-6200). Such quantitative data and further correlations between 5-HT innervation density and other measurable aspects of cortical structure and function should help to elucidate the role(s) of 5-HT in this part of the brain.