Response of diademed sifaka (Propithecus diadema) to fosa (Cryptoprocta ferox) predation in the Betampona Strict Nature Reserve, Madagascar.

Large-bodied mammals living in fragmented habitats are at higher risk of extinction, and such risk can be influenced by ecological factors such as predator-prey system dynamics. These dynamics can be particularly complex for conservation management when one endangered species preys on another endangered species in an isolated or poor-quality habitat. Here we describe predation events observed over 19 months that involved two threatened species: the largest carnivore in Madagascar, the fosa (Cryptoprocta ferox), and three groups of diademed sifaka (Propithecus diadema) in the Betampona Strict Nature Reserve. This site is a 22 km2 low-altitude rainforest that is surrounded by agricultural land and isolated from larger forest corridors. We aim to (1) assess the behavioral changes of P. diadema in response to fosa attacks and identify any antipredator strategies that they adopted, and (2) quantify the frequency of fosa attacks and the predation impact on the sifaka population. We report five direct observations of fosa predation attempts (one successful), the discovery of a dead sifaka with evidence of fosa predation, and the disappearance of three individuals. We describe the observed attacks and compare the sifaka activity budgets and movement patterns before and after the events. To escape the predator, sifakas fled short distances, hid, and remained vigilant. The impact of predation, combined with low reproductive rates and potentially high inbreeding of this isolated diademed sifaka population, could affect the survival of this species in Betampona. Given the compounding effects of habitat isolation and high hunting pressure, community-specific conservation strategies should incorporate predator-prey dynamics via longitudinal monitoring of predator and prey population densities and quantifying the predation pressure between them.

Faecal parasites increase with age but not reproductive effort in wild female chimpanzees.

Energy investment in reproduction is predicted to trade off against other necessary physiological functions like immunity, but it is unclear to what extent this impacts fitness in long-lived species. Among mammals, female primates, and especially apes, exhibit extensive periods of investment in each offspring. During this time, energy diverted to gestation and lactation is hypothesized to incur short and long-term deficits in maternal immunity and lead to accelerated ageing. We examined the relationship between reproduction and immunity, as measured by faecal parasite counts, in wild female chimpanzees (Pan troglodytes schweinfurthii) of Kibale National Park, Uganda. While we observed higher parasite shedding (counts of eggs, cysts and larvae) in pregnant chimpanzees relative to cycling females, parasites rapidly decreased during early lactation, the most energetically taxing phase of the reproductive cycle. Additionally, while our results indicate that parasite shedding increases with age, females with higher fertility for their age had lower faecal parasite counts. Such findings support the hypothesis that the relatively conservative rate of female reproduction in chimpanzees may be protective against the negative effects of reproductive effort on health. This article is part of the theme issue 'Evolution of the primate ageing process'.

Complications of endoscopic retrograde cholangiopancreatography (ERCP) and their risk factors.

PURPOSE: Determination of the type and frequency of complications developing after diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) as well as the risk factors predisposing to them. MATERIAL/METHODS: The retrospective study, including 734 ERCP performed in 550 patients, with 404 (55%) ES (endoscopic sphincterotomy) during a 4-year period. RESULTS: Among 734 ERCP procedures, 76.4% (561) had both diagnostic and therapeutic purpose, 15.2% (112) were only diagnostic. Complications developed after 26 procedures (3.5%): acute pancreatitis (AP) in 8 patients (1.09%), cholangitis in 7 (0.95%) and delayed bleeding in 11 (1.5%) patients. After 49 (6.7%) ES immediate bleeding was observed. The risk factors for AP were: unintentional pancreatic duct contrasting, mechanical lithotripsy, the use of the "pre-cut" technique and bile duct dilatation. Cholangitis was more common in cases with difficult cannulation at older age and with lower baseline bilirubin level. The risk factors for delayed bleeding were: location of the ampulla of Vater in the diverticulum and the use of the "precut" technique. Immediate bleeding was more frequent after revision of bile ducts with Dormia's basket or with balloon, after introduction of contrast medium to the pancreatic duct or in ductal cholelithiasis. CONCLUSIONS: ERCP performed in the endoscopy unit of a specialist hospital department is a relatively safe procedure, with a low burden of complications as compared to the benefits it provides to appropriately qualified patients.

[The effect of intragastric balloon on serum lipids level in patients with morbid obesity]. / Wplyw leczenia balonem wewnatrz-zoladkowym na stezienie lipidów w surowicy u pacjentów z otyloscia olbrzymia.

Obesity is recently considered as the twentieth first century epidemy. An excessive accumulation of adipocytes that constitute metabolically active tissue, plays an important role in lipid and carbohydrate metabolism. In the morbidly obese population dyslipidemia is common. AIM OF OUR STUDY: To determine the content of total cholesterol (TC), HDL-cholesterol (HDL), LDL-cholesterol (LDL) and triacylglicerol (TG) in obese subjects treated with the Bioenterics Intragastric Balloon (BIB). MATERIAL AND METHODS: BIB was placement for 6 months in 21 obese patients, mean age 40 (21-60), with BMI 473 +/- 5.7 kg/m2. The control group consisted of 15 morbidly obese patients treated conservatively. Plasma lipid concentration were assessed by the enzymatic methods. RESULTS: No major complications have been noted in patients with BIB. However, nearly all patients complained of discomfort, nausea and vomiting for the first few days. Over a 6-month-period, a reduction in body mass in the BIB group was 17.1 +/- 8.0 kg as compared to 3.2 +/- 6.4 kg in the control group (p = 0.00003). The biggest reduction in body mass was observed during first month. After one month, total cholesterol (TC) decreased by 17.6% (p < 0.001), triacylglycerol (TG) decreased by 25.5% (p = 0.01), low-density lipoprotein cholesterol (LDL) decreased by 27.5% (p < 0.001). In the control group, the corresponding levels of TC, TG and LDL remained unchanged. The level of HDL increased in both group. CONCLUSIONS: In patients with morbid obesity treated with BIB, weight loss is accompanied by a decrease in concentration TC, LDL and TG and increase in plasma HDL. The reduction of lipid concentration in blood serum may cut down cholesterol-lowering therapy and diminish the risk for development of coronary heart disease.

The effect of intragastric balloon on plasma ghrelin, leptin, and adiponectin levels in patients with morbid obesity.

CONTEXT: Ghrelin and leptin are hormones regulating appetite and metabolic processes. Adiponectin plays an important role in the modulation of glucose and lipid metabolism. OBJECTIVE: The objective of the study was to evaluate the levels of plasma ghrelin, leptin, and adiponectin in obese subjects treated with bioenterics intragastric balloon (BIB), low-calorie diet (1500 kcal), and physical exercise. DESIGN: BIB was placed for 6 months in 21 subjects with body mass index 47.3 +/- 5.7. The control group consisted of 15 morbidly obese subjects treated with a low-calorie diet and physical effort. Plasma hormone levels were determined by RIA. RESULTS: In the BIB group, the insertion of the balloon caused a considerable reduction in body mass over a 6-month period (17.1 +/- 8.0 kg) as compared with the control group (3.2 +/- 6.4 kg). After 1 month, the levels of ghrelin increased from 621.9 +/- 182.4 to 903.9 +/- 237 pg/ml and thereafter gradually decreased, reaching the starting level 3 months after the removal of the balloon. In the same group, the levels of leptin decreased from 61.3 +/- 36.7 to 39.9 +/- 17.5 ng/ml. In the control group, the corresponding levels of ghrelin and leptin remained relatively stable. During the observation period, in the BIB group, the levels of adiponectin remained unchanged as opposed to a transient increase noted in the control group. CONCLUSIONS: In patients with morbid obesity, weight loss induced by BIB is associated with a decrease in plasma leptin and a transient elevation of plasma ghrelin. It is likely that the changes in hormones regulating the energy balance caused by BIB can prevent an increase in adiponectin level.

Alpha male chimpanzee grooming patterns: implications for dominance "style".

In social primates, individuals use various tactics to compete for dominance rank. Grooming, displays and contact aggression are common components of a male chimpanzee's dominance repertoire. The optimal combination of these behaviors is likely to differ among males with individuals exhibiting a dominance "style" that reflects their tendency to use cooperative and/or agonistic dominance tactics. Here, we examine the grooming behavior of three alpha male chimpanzees at Gombe National Park, Tanzania. We found that (1) these males differed significantly in their tendency to groom with other males; (2) each male's grooming patterns remained consistent before, during and after his tenure as alpha, and (3) the three males tended to groom with high- middle- and low-ranking partners equally. We suggest that body mass may be one possible determinant of differences in grooming behavior. The largest male exhibited the lowest overall grooming rates, whereas the smallest male spent the most time grooming others. This is probably because large males are more effective at physically intimidating subordinates. To achieve alpha status, a small male may need to compensate for reduced size by investing more time and energy in grooming, thereby ensuring coalitionary support from others. Rates of contact aggression and charging displays conformed to this prediction, suggesting that each male exhibited a different dominance "style."

The cumulative effect of nuclear factor-kappaB (NF-kappaB) inhibition and endothelins in early cerulein-induced acute pancreatitis in rats.

PURPOSE: To assess effects of NF-kappaB activation inhibitor (pyrrolidine dithiocarbamate--PDTC) alone or with endothelins (ET-1, ET-2, ET-3) in early course of cerulein-induced acute pancreatitis (AP) in rats. MATERIAL AND METHODS: After 4 h of AP in Wistar rats, treated with PDTC 10 or 40 mg/kg or with PDTC 10 mg/kg and ET-1, ET-2 or ET-3, 0.5 or 1.0 nmol/kg twice i.p. in 1 h interval, free active trypsin (FAT), total potential trypsin (TPT) and lipase in 12000 x g supernatants of pancreatic homogenates, plasma alpha-amylase and histological changes were assayed. %FAT/TPT was an index of trypsinogen activation. RESULTS: %FAT/TPT significantly increased to 12.42 +/- 2.14%, lipase to 5.51 +/- 0.84 U/mg protein and alpha-amylase to 28.5 +/- 5.61 U/mL in AP vs 1.96 +/- 0.31%, 1.29 +/- 0.11 U/mg and 5.80 +/- 1.38 U/ml in healthy control. Higher dose PDTC attenuated trypsinogen activation to 3.01 +/- 0.53% and alpha-amylase to 15.3 +/- 1.38. PDTC and ET-1 attenuated %FAT/TPT to 2.55 +/- 0.18% with lower and 2.34 +/- 0.44% with higher dose. ET-3 was less effective than ET-1: 6.76 +/- 0.46% with lower dose. Lower doses of ET-1 and ET-2 with PDTC, diminished lipase activity to 2.60 +/- 0.36 and 2.94 +/- 0.33. CONCLUSIONS: Cumulative attenuation of trypsinogen activation after lower dose of PDTC and ET-1 approximated the effect of higher dose of PDTC. Additional effect of ET-3 was weaker than ET-1, and ET-2 was ineffective in this respect. The combination of this NF-kappaB activation inhibitor and ET-1 could be beneficial in early course of edematous AP by attenuating of trypsinogen activation. However, it should be treated with caution because of some unfavorable effects on histological scores of pancreatic injury.

The effect of endothelin-1, endothelin-2 and endothelin-3 in early cerulein-induced acute pancreatitis in rats.

PURPOSE: To assess the effect of endothelins: ET-1, ET-2 and ET-3 on trypsinogen activation, lipase activity and histological changes in the pancreas in early (4 hrs) cerulein acute pancreatitis (AP) in rats. MATERIAL AND METHODS: In 45 Wistar rats with cerulein induced AP (2 x 40 microg/kg i.p. at 1 hour interval, the effect of endothelins at the dose 2 x 0.5 or 2 x 1.0 nmol/kg i.p. was assessed vs untreated AP; 6 healthy rats were control (C). Free active trypsin (FAT), total potential trypsin after activation with enterokinase (TPT), lipase in 12000 xg supernatants of pancreatic homogenates and the plasma alpha-amylase were assayed. The %FAT/TPT was an index of trypsinogen activation. RESULTS: %FAT/TPT increased from 3.0 +/- 0.6 in C to 16.2 +/- 3.1 in AP (p < 0.01). ET-1 decreased this index to 4.8 +/- 1.1 after higher dose (p < 0.01); the effect of lower dose was insignificant. Attenuating effect of ET-2 was significant: 7.3 +/- 1.7 after higher dose (p < 0.05) and 6.1 +/- 0.9 after lower dose (p < 0.01). ET-3 diminished this index to 4.5 +/- 1.5 (p < 0.01) and to 6.3 +/- 2.2 (p < 0.05) respectively. Lipase activity in supernatant increased from 4.1 +/- 0.6 in C to 6.3 +/- 0.7 U/mg protein in untreated AP (p < 0.05) and plasma alpha-amylase from 7.0 +/- 0.6 in C to 25.9 +/- 4.3 U/ml in AP (p < 0.001), without essential changes in treated groups vs untreated AP. Higher doses of endothelins decreased inflammatory cell infiltration score in AP. CONCLUSIONS: The exogenous endothelins, especially ET-2 and ET-3 and to lesser extent ET-1 exerted some protective effect in early, edematous acute pancreatitis by the attenuation of trypsinogen activation and inflammatory cell infiltration in the pancreas.

Does chronic ethanol administration have influence on pancreatic regeneration in the course of caerulein induced acute pancreatitis in rats.

UNLABELLED: This study was undertaken in order to determine the influence of chronic ethanol administration on pancreatic regeneration during acute pancreatitis (AP). Rats were pair fed with isocaloric diet containing or not ethanol. After 8 weeks of such feeding AP was induced by s.c. injection of caerulein (Cae). 6 h, 24 h and 5 days after first Cae dose pancreatic weight, amylase, chymotrypsin, protein, RNA, DNA contents were determined and phosphatidic acid (PA) production in isolated pancreatic acini was measured. Proliferating cells were quantified by immunochemical staining of cells incorporating bromodeoxyuridine (BrdU). RESULTS: Pancreatic weight was significantly higher at 6 h after first Cae injection in both, ethanol fed (EF) and control groups (C), however at 24 h pancreatic weight did not differ from prior to AP induction in EF rats. Ethanol feeding (EF) did not influence significantly protein, chymotrypsin and amylase content in pancreatic tissue in groups with AP. In EF rats RNA content after 5 days of AP was higher than in control animals. Total DNA content in EF rats with AP was lower 6 h after AP induction, earlier than in control animals with AP. Immunochemistry showed higher labelling index for BrdU after 6 h, 24 h and 5 days of AP in EF rats. In contrast to this findings, in EF animals, AP induction was not able to stimulate further PA accumulation. CONCLUSION: We conclude that chronic ethanol feeding, while inhibiting PA accumulation in comparison to control group, does not impair pancreatic tissue regeneration during the early phase of Cae-induced AP. Stimulation of regenerative/reparative processes in EF rats during Cae-induced AP seems to be even more pronounced than in the control group.

Pancreatic regeneration after chronic ethanol feeding in rats.

UNLABELLED: Increase of phosphatidic acid (PA) accumulation in response to caerulein (Cae) and after subtotal pancreatectomy (SP) has been previously described and phospholipase D (PLD) derived PA involvement in pancreatic regeneration was suggested. We also described decrease of Cae stimulated PA accumulation after a single dose of ethanol (both in vitro and in vivo). The present study was undertaken in order to determine the influence of chronic ethanol feeding on basal and Cae stimulated PA accumulation and other parameters of pancreatic regeneration in control and ethanol feed rats. Male rats were pair fed ad libitum with an isocaloric liquid diet (Lieber De Carli) with or without ethanol. In vitro study: pair fed rats were killed after 2 or 6 weeks of feeding, pancreata were dissected out and weighted, dispersed pancreatic acini were then prepared and loaded with 3H myristic acid in order to label the phosphatidylcholine pool. Phosphatidic acid (3H PA) accumulation, in the presence of propranolol, was measured after stimulation with increasing doses of Cae. In vivo study: PA was measured 3 days after SP or sham operation in both groups of rats, and also after 1 h of Cae infusion (0.25 microg/kg/h). Pancreatic weight, amylase, protein, RNA and DNA content were established. RESULTS: In vitro study 1) Basal PLD activity expressed as PA accumulation was significantly elevated after 6 weeks of ethanol feeding in comparison to the control values (28%). 2) Cae in doses ranging from 100 pM to 5 nM was not able to stimulate PA accumulation in isolated pancreatic acini prepared from ethanol fed rats. In vivo study: 1) Body weight and pancreatic weight were similar in, both the ethanol fed and the control groups, after 2 and 6 weeks. 2) Ethanol feeding significantly decreased total amylase content in the pancreas, but did not change protein, RNA and DNA content. 3) in contrast to the control animals in which SP caused a 71.1% increase of PA accumulation over the sham operation, subtotal pancreatectomy was not able to stimulate PA in rats fed with ethanol. 4) Also Cae infusion did not stimulate PA accumulation in the ethanol fed animals in comparison to the controls. Since the involvement of PLD activation in the early stages of pancreatic regeneration was postulated, our results suggest that chronic ethanol feeding can influence this process by decrease of PA production, probably because of the inhibition of hydrolytic PLD activity in the presence of ethanol. This could be one of the mechanisms responsible for pancreatic injury after chronic ethanol consumption.

The effect of beta-thia-iminoprostacyclin in taurocholate acute pancreatitis in rats: the role of antecedent acute ethanol abuse.

The promoting effect of acute ethanol (E) abuse and protective effect of prostaglandin derivatives in acute pancreatitis (AP) remain obscure. The aim of this study was to assess the effect of previous intake of high-dose E on trypsinogen (Tn) activation and labilization of pancreatic lysosomal membranes (PLM), in taurocholate AP in rats, considering treatment with stable beta-thia-iminoprostacyclin (T). In 60 male Wistar rats taurocholate AP was induced or a sham operation was performed. Half of them received 40% E (5 g/kg body weight), 6 h earlier. T (0.3 mg/kg body weight i.g.) was applied before E or before the induction of AP. Free active (FAT) and total potential (TPT) trypsin, free (F) and total (T) cathepsin B, phospholipase A2 (PLA2), and lipase (L) activities were assayed. Percentage FAT/TPT was an index of Tn activation and fractional free (% F/T) activity of cathepsin B was an index of PLM fragility. FAT increased after 12 h of AP, and in E rats this increase was even more evident. Pretreatment and treatment with T partly prevented this increase, however, this effect was abolished or limited in rats previously given E-the changes were not effected by T. PLA2 and L activities in AP were not diminished after T. The promoting effect of acute E abuse prior to AP could be dependent on augmented activation of Tn and labilization of PLM. The protective effect of T seems to be dependent on the decrease in Tn activation in pancreatitic tissue. The potential therapeutic effect of this drug in AP could be limited by previous acute E intake, as evidenced by differences in histopathological changes.

Does antecedent ethanol intake affect course of taurocholate pancreatitis in rats?

The pathogenic role of acute ethanol abuse in acute pancreatitis (AP) is still obscure. The aim of the study was to evaluate the effect of antecedent intake of a high dose of 40% ethanol (5 g/kg body wt.), on trypsinogen activation, pancreatic lysosomal membrane labilization, and activities of phospholipase A2 and lipase in taurocholate AP in rats. In 80 male Wistar rats, AP or sham operation (SO) was produced 6 hr after intragastric saline (S) or ethanol (E) administration, and animals were sacrificed after 6, 12, and 18 hr. Free active trypsin (FAT) and total potential trypsin (TPT) were assayed in the pancreatic homogenate. Percentage free activity (%F/T) of cathepsin B was determined as an index of lysosomal membrane fragility. The most evident activation of trypsin occured at 6 hr AP (11.6% of TPT in S group and 16.4% in E group). Antecedent ethanol increased FAT 18 hr after SO from 0.105 +/- 0.048 microg/g protein to 0.258 +/- 0.054 and AP lasting 18 hr from 0.331 +/- 0.072 to 0.695 +/- 0.110. The %F/T of cathepsin B was highest at 18 hr of AP, suggesting maximal labilization of lysosomal membranes at this time. This labilization occurred earlier (at 12 hr of AP) in E group. The increasing effect of antecedent E on lipolytic enzymes was evident after 6 hr of AP. In conclusion, the antecedent intake of high dose of ethanol significantly promoted the conversion of trypsinogen to trypsin in taurocholate acute pancreatitis, whereas its additional effect toward labilization of pancreatic lysosomal membranes and the increase of lipolytic enzymes activities was less evident. Therefore, the promoting impact of acute ethanol intake in the development of acute pancreatitis could be mainly dependent on its increasing effect on trypsinogen activation.

The effect of tilsuprost on the liver mitochondria in taurocholate pancreatitis in rats with antecedent acute ethanol abuse.

The damage to the liver appears to be an important aspect of multisystem organ failure in acute pancreatitis with poor prognosis. The objective of this study was to evaluate the protective effect of stable prostacyclin analogue--tilsuprost on the liver energy metabolism in taurocholate pancreatitis in rats preceded by acute ethanol intake. The respiratory control ratio (RCR) and ADP/O ratio of liver mitochondria with glutamate+malate as substrates and mitochondrial DNP (uncoupler)-dependent ATPase activity were significantly depressed after 12 h of taurocholate pancreatitis-the effects that were not significantly aggravated by antecedent acute ethanol intake. Tilsuprost (0.3 mg/kg i.g.) given just before induction of pancreatitis partly prevented the impairment of mitochondrial oxidative and phosphorylative functions, however these positive effects were limited in acute pancreatitis preceded by acute ethanol intake. These results suggest that prostacyclin analogues could be effective in the treatment of hepatic complications in acute pancreatitis, however their effectiveness could be limited in the case of acute ethanol antecedent abuse.

Hepatic mitochondrial and lysosomal alterations in acute experimental pancreatitis with ethanolic coetiology in rats.

In order to assess the cumulative effects of antecedent acute ethanol intake and acute pancreatitis on the liver, the mitochondrial respiratory functions and lysosomal membrane integrity of the liver were evaluated in taurocholate pancreatitis (AP) in rats, induced 6 hr after intragastric ethanol 40% (5 g/kg body wt). The oxygen consumption rate, RCR (respiratory control ratio), and ADP/O ratio were measured according to Estabrook. Fractional free activity of lysosomal hydrolases was assayed. RCR with glutamate + malate was most decreased at 12 hr of AP with partial improvement after 18 hr. The ADP/O ratio dropped maximally after 18 hr of AP. The fragility of lysosomal membranes increased significantly at 18 hr of AP. The antecedent ethanol intake abolished the partial restoration of RCR after 18 hr; however, it did not affect the ADP/O ratio or the integrity of lysosomal membranes impaired in AP at this time. In conclusion, the antecedent acute ethanol abuse could aggravate the liver mitochondrial deterioration, but not the lysosomal membrane labilization seen in AP.

Echocardiographic features of carcinoid heart disease.

We reviewed the records of the Mayo Clinic patients with known carcinoid syndrome in whom echocardiographic studies had been done. Nineteen patients had M-mode and 2-dimensional echocardiographic examinations, and 1 patient had an M-mode examination only. Of the 20 patients, 8 had no evidence by echocardiogram of carcinoid heart disease; 2 had changes in the tricuspid valve echogram suggestive of early carcinoid heart disease, and the other 10 patients had the following distinctive echocardiographic findings: (1) the pattern of right ventricular volume overload (enlarged right ventricle with abnormal septal motion); (2) abnormal right-sided valves, including (a) a striking appearance of the tricuspid valve, the leaflets appearing thickened, retracted, and fixed in a semiopen position throughout the cardiac cycle, and (b) thickened, retracted pulmonic valve cusps, when visualized; and (3) the left-sided valves and chambers rarely involved. These echocardiographic features are distinctive of advanced carcinoid heart disease and correlate closely with pathologic findings.

False positive stress tests due to undetected left ventricular hypertrophy.

Without large vessel coronary artery disease, clinically evident left ventricular hypertrophy (LVH) is an identified cause of ischemic ST segment changes during exercise. The contribution of subclinical LVH to false positive exercise stress test was evaluated from data of 31 patients without electrocardiographic evidence of LVH who underwent concurrent exercise stress testing, M-mode echocardiography and coronary arteriography at Temple University Hospital, Philadelphia, PA, between January, 1976, and December, 1979, and who met echocardiographic criteria for LVH. Using Bayes theorem, the authors found the probability was 0.59 that a patient with electrocardiogram-undetected LVH does not have significant coronary disease with a positive stress test. The probability of normal coronary arteries with a positive stress test in patients without LVH on echocardiogram was 0.24. Inapparent LVH detected by echocardiography increases the likelihood that a patient with a positive stress test does not have coronary disease. Thus, the positive exercise electrocardiogram should be cautiously interpreted in apparently normal patients who have LVH detectable only by echocardiography.

Right ventricular performance in mitral stenosis.

Until recently, the dynamic geometry and pump function of the pressure-overloaded right ventricle in patients with mitral stenosis and pulmonary hypertension had not been well defined. With use of a recently developed method for calculating right ventricular volume in human beings, seven normal subjects and eight patients with mitral stenosis and pulmonary hypertension had right ventricular performance assessed from computer-analyzed biplane right ventriculograms. Patients with mitral stenosis has elevated values for systolic right ventricular pressure (mean +/- standard error of the mean 25 +/- 2 for normal subjects, 57 +/- 6 mm Hg for patients with mitral stenosis), but normal values for right ventricular end-diastolic volume index (normal 95 +/- 11, patients 81 +/- 9 ml/m2) and ejection fraction (normal 0.49 +/- 0.02, patients 0.58 +/- 0.04). Comparison of right ventricular function using group performance curves of stroke work versus end-diastolic volume revealed the slope of the mitral stenosis line to be significantly greater than the normal line. A plot of right ventricular stroke volume versus end-diastolic volume, which removes pressure from the performance index, revealed that the two groups have similar performance. Left ventricular function measured by ejection fraction was reduced in mitral stenosis. These data suggest that the right ventricle performs normally in patients with mitral stenosis with moderate pulmonary hypertension and maintains normal size and ejection fraction.