Myeloid sarcoma with NPM1 mutation may be clinically and genetically distinct from AML with NPM1 mutation: a study from the Bone Marrow Pathology Group

Myeloid sarcoma (MS) is currently considered equivalent to de novo acute myeloid leukemia (AML); however, the relationship between these entities is poorly understood. This retrospective multi-institutional cohort study compared 43 MS with NPM1 mutation to 106 AML with NPM1 mutation. Compared to AML, MS had more frequent cytogenetic abnormalities including complex karyotype (p = .009 and p = .007, respectively) and was enriched in mutations of genes involved in histone modification, including ASXL1 (p = .007 and p = .008, respectively). AML harbored a higher average number of gene mutations (p = .002) including more frequent PTPN11 mutations (p < .001) and mutations of DNA-methylating genes including DNMT3A and IDH1 (both p < .001). MS had significantly shorter overall survival (OS) than AML (median OS: 44.9 vs. 93.2 months, respectively, p = .037). MS with NPM1 mutation has a unique genetic landscape, and poorer OS, compared to AML with NPM1 mutation.

Management of thoracic trauma

Managing major thoracic trauma begins with identifying and anticipating injuries associated with the mechanism of injury. The key aims are to reduce early mortality and the impact of associated complications to expedite recovery and restore the patient to their pre-injury state. While imaging is imperative to identify the extent of thoracic trauma, some pathology may require immediate treatment. The majority can be managed with adequate pleural drainage, but respiratory failure and poor gas exchange may require either non-invasive or invasive ventilation. Ventilation strategies to protect from complications such as barotrauma, volutrauma and ventilator-induced lung injury are important to consider. The management of pain is vital in reducing respiratory complications. A multimodal strategy using local, regional and systemic analgesia may mitigate respiratory side effects of opioid use. With optimal pain management, physiotherapy can be fully utilised to reduce respiratory complications and enhance early recovery. Thoracic surgeons should be consulted early for consideration of surgical management of specific injuries. With a greater understanding of the mechanisms of injury and the appropriate use of available resources, favourable outcomes can be reached in this cohort of patients. Overall, a multidisciplinary and holistic approach results in the best patient outcomes.

Molecular Pathogenesis of Primary Gastrointestinal Tract Lymphomas

Primary gastrointestinal lymphomas are rare though the incidence is significantly increased among adult patients in recent years. The majority of the patients present with symptoms overlapping with other gastrointestinal disorders and imaging findings are not specific. Therefore, histologic examination is necessary to establish the diagnosis. Insight into etiologies, molecular pathogenesis and critical signaling pathways in lymphomas including gastrointestinal lymphomas has significantly expanded within the last 3 decades. Given the increasing demand for incorporation of genetic data, the appropriate handling and processing of small endoscopic gastrointestinal biopsy samples of suspected lymphoma is becoming extremely crucial and at times challenging. The use of next generation sequencing with analysis of genes relevant to diagnosis, prognosis, and therapeutic targets continues to have a significant promising impact on management of patients in lymphoid malignancies. In particular, the identification of constitutively activated pathways and the emergence of novel targeted medications predict that more effective therapies will be identified for these disorders in the coming years.

STAT3 Activation in Circulating Monocytes Contributes to Neovascular Age-Related Macular Degeneration

Infiltrating macrophages are critically involved in pathogenic angiogenesis such as neovascular age-related macular degeneration (nAMD). Macrophages originate from circulating monocytes and three subtypes of monocyte exist in humans: classical (CD14⁺CD16^-), non-classical (CD14^-CD16⁺) and intermediate (CD14⁺CD16⁺) monocytes. The aim of this study was to investigate the role of circulating monocyte in neovascular age-related macular degeneration (nAMD). Flow cytometry analysis showed that the intermediate monocytes from nAMD patients expressed higher levels of CX3CR1 and HLA-DR compared to those from controls. Monocytes from nAMD patients expressed higher levels of phosphorylated Signal Transducer and Activator of Transcription 3 (pSTAT3), and produced higher amount of VEGF. In the mouse model of choroidal neovascularization (CNV), pSTAT3 expression was increased in the retina and RPE/choroid, and 49.24% of infiltrating macrophages express pSTAT3. Genetic deletion of the Suppressor of Cytokine Signalling 3 (SOCS3) in myeloid cells in the LysM-Cre^+/-:SOCS3^fl/fl mice resulted in spontaneous STAT3 activation and accelerated CNV formation. Inhibition of STAT3 activation using a small peptide LLL12 suppressed laser-induced CNV. Our results suggest that monocytes, in particular the intermediate subset of monocytes are activated in nAMD patients. STAT3 activation in circulating monocytes may contribute to the development of choroidal neovascularisation in AMD.

The beneficial effect of plasmapheresis in mixed connective tissue disease with coexisting antiphospholipid syndrome

The authors report a rare case of a female patient with mixed connective tissue disease (MCTD) with coexisting antiphospholipid syndrome (APS). Five years after the diagnosis of MCTD high concentrations of anticardiolipin (anti-CL) and anti-β2-glycoprotein (anti-β2GPI) autoantibodies were present in the patient’s serum without thrombotic events. Epstein-Barr virus (EBV) reactivation provoked APS, with the clinical manifestations of livedo reticularis, digital gangrene and leg ulcers. Skin biopsy from the necrotic area showed multiple fibrin microthrombi in the superficial vessels. Corticosteroid pulse therapy, and plasma exchange in combination with synchronized cyclophosphamide was administered, which led to improvement of the digital gangrenes, while no new lesions developed. The number of CD27high plasma cells decreased, and the previous high levels of autoantibodies also normalized in the peripheral blood. In the case of MCTD with coexisting APS combination therapy, including plasmapheresis has beneficial effects.

Alteration of serum semicarbazide-sensitive amine oxidase activity in chronic renal failure

Despite recent intensive investigations, physiological and pathological role of semicarbazide-sensitive amine oxidase (SSAO) is far from clear. In this study, serum SSAO activity was determined, radiochemically, in various groups of uremic patients: haemodialysed (HD), peritoneally dialysed (PD) and those receiving conservative treatment but still not dialysed (ND), as well as in controls. Reduced enzyme activity was found in HD uremic patients before and after dialysis treatment, compared to controls (5260 +/- 862 and 6011 +/- 958 pmol/h/ml vs. 8601 +/- 283 pmol/h/ml, p < 0.01 and p < 0.05, respectively). The activity was slightly lower in PD, and normal in ND patients. In HD patients SSAO activity was also determined by an assay based on the formation of hydrogen peroxide, and was found to be elevated compared to controls (2384 +/- 323 pmol/h/ml vs. 1437 +/- 72 pmol/h/ml, p < 0.05). The elevated serum SSAO activity measured through the detection of the enzyme-generated hydrogen peroxide in HD patients might indicate its contribution to the accelerated atherosclerotic disease observed in uremia.

Transvaginal extraction of the laparoscopically removed spleen

Laparoscopic removal of normal and moderately enlarged spleens has become the gold standard operation in recent years because its short operative time, technical safety, and quick patient recovery time. The best method for extraction of the removed spleen, however, has not yet been determined. The authors present a new method for the extraction of the laparoscopically removed spleen. Using a transvaginal approach, the organ is removed through an incision on the posterior vaginal wall and exteriorized in a laparobag. The procedure is similar to a routine vaginal hysterectomy, but is technically much simpler to perform.

Waterhouse-Friderichsen syndrome secondary to Capnocytophaga canimorsus septicemia and demonstration of bacteremia by peripheral blood smear

Waterhouse-Friderichsen syndrome caused by Capnocytophaga canimorsus septicemia was fatal in a previously healthy 47-year-old woman. The patient died suddenly in less than 12 hours after presentation, in spite of supportive measures, including ventilation, antibiotic coverage, pressor therapy, and multiple transfusions of blood products. The diagnosis of infection due to an unusual organism was suspected earlier in the course of management after review of the peripheral blood smear. The importance of the findings in the blood smear and their correlation with infection due to this organism are discussed.

Graves' ophthalmopathy: eye muscle involvement in patients with diplopia

BACKGROUND

Diplopia identifies patients with eye muscle involvement in Graves' ophthalmopathy (GO).

OBJECTIVE

To identify clinical parameters that could eliminate the need for magnetic resonance imaging (MRI) to assess the activity of inflammation in the eye muscles of GO patients with diplopia.

METHODS

In 43 patients with GO with recently developed diplopia, orbital ultrasound and MRI were performed. Muscle diameters and MRI T2 relaxation times were measured, and the amount of orbital connective tissue was calculated from MRI scans and compared with ultrasound readings, diplopia grades, degree of protrusion, ocular pressure, tear production, antibody levels and hormonal parameters of thyroid function.

RESULTS

No correlation was found between diameters of 233 extraocular muscles measured by MRI and by ultrasound. For each of the four muscles, there was a diameter above which ultrasound was always unreliable. MRI data were used in further analysis. Of the muscles examined, the inferior rectuses were the most frequently enlarged - at least one, in 93% of cases. Medial, lateral and superior rectuses were enlarged in 59%, 37% and 34% of the orbits respectively. The pattern of muscle involvement of the two orbits tended to be symmetric (r=0.49, P=0.003), particularly for the medial rectuses (r=0.90, P=0.000). Proptosis correlated with the sum of the muscle diameters for a given eye (right eye: r=0.54, P=0.003; left eye: r=0.57, P=0.001), but it failed to correlate with the amount of orbital connective tissue. In 53% of the patients, normal T2 relaxation times were found in all eight muscles. There was only a weak correlation between muscle thickness and T2 relaxation time (r=0.49, P=0.003), indicating that muscle enlargement alone is not a sign of disease activity. The severity of diplopia was independent of T2 relaxation time. The amount of orbital connective tissue showed a negative correlation with the greatest T2 relaxation time for a given eye (r= -0.52, P=0.004); this suggests that disease types exist that have predominant muscle involvement and predominant connective tissue expansion. No correlation between connective tissue expansion and proptosis, diplopia grade, muscle thickness or disease duration was found - that is, connective tissue expansion is not a major factor in diplopia. Both muscle and connective tissue findings were independent of thyroid function.

CONCLUSION

Ultrasound and MRI eye muscle diameter readings do not correlate, because of the inherent inaccuracy of orbital ultrasound. Muscle enlargement alone does not mean oedematous swelling and active disease. Neither ultrasound, nor any combination of 11 clinical and laboratory parameters provided the degree of information on muscles and connective tissue that was obtainable by MRI. In unclear cases of recently developed diplopia, before orbital decompression surgery, in the case of treatment failure or if, for any other reason, imaging is needed in GO, MRI is the method of choice.

Regulation of the apolipoprotein B in heterozygous hypobetalipoproteinemic knock-out mice expressing truncated apoB, B81. Low production and enhanced clearance of apoB cause low levels of apoB

Low levels of cholesterol are protective against development of coronary artery disease. Heterozygous hypobetalipoproteinemic individuals expressing truncated apolipoprotein (apo)B as a result of mutation in the apob gene have low levels of cholesterol and apoB in their plasma. To study the molecular mechanism of low levels of apoB in these individuals, we employed a previously reported knock out mouse model generated by targeted modification of the apob gene. The heterozygous, apoB-100/B-81, mice express full length and truncated apoB, B-81, and have 20 and 35% lower levels of total cholesterol and apoB, respectively, when compared to WT (apoB-100/B-100) mice. The majority of the truncated apoB, B-81, fractionated in the VLDL- density range. The mechanism of low levels of apoB in B-100/B-81 mice was examined. Total hepatic apoB mRNA levels decreased by 15%, primarily due to lower levels of apoB-81 mRNA. Since apoB mRNA transcription rates were similar in B-100/B-100 and B-100/B-81 mice, low levels of mutant apoB-81 mRNA occurred by enhanced degradation of apoB mRNA transcript containing premature translational stop codon. ApoB synthesis measured on isolated hepatocytes decreased in B-100/B-81 mice by 35%, while apoB-48, apoE, and apoAI syntheses remained unchanged. Metabolic studies using whole animal showed a 32% decrease in triglyceride secretion rates, consistent with the apoB secretion rates. Inhibition of receptor-mediated clearance of apoB-81-containing particles resulted in greater relative accumulation of apoB-81 in plasma than apoB-100, suggesting enhanced clearance of apoB-81-containing particles. These results demonstrate that low levels of apoB in heterozygous hypobetalipoproteinemic mice occurs by low rates of apoB secretion, and increased clearance of truncated apoB. Similar mechanisms appear to contribute to low levels of apoB in hypobetalipoproteinemic humans.

Monoclonal antibody MAb-170 for immunoscintigraphic detection of ovarian tumors

OBJECTIVE

The technetium Tc 99m-labeled monoclonal antibody MAb-170 was designed for diagnostic use in patients with gynecologic adenocarcinoma. Our investigation was initiated to verify its usefulness for radioimmunoscintigraphy of ovarian tumors.

STUDY DESIGN

Most of the 82 patients participating in this study underwent immunoscintigraphy before first-look surgery.

RESULTS

Radioimmunoscintigraphy recognized 36 of 41 patients with adenocarcinoma of the ovaries, corresponding to an overall sensitivity of 88%. Specificity was 90% (38/42). The calculation of accuracy gave a result of 89% (74/83). Of 110 known lesions, 92 were visualized successfully; thus the local-regional sensitivity was 84%. Of 160 benign tumor sites, 154 showed no evidence of tracer accumulation, corresponding to a local-regional specificity of 96%. The smallest lesion visualized was an adenocarcinoma of the corpus uteri with a diameter of 1.5 cm.

CONCLUSION

The monoclonal antibody MAb-170 is a promising radiopharmaceutical for immunoscintigraphy of ovarian adenocarcinoma.

Selective antibody reactivity with peptides from human endogenous retroviruses and nonviral poly(amino acids) in patients with systemic lupus erythematosus

OBJECTIVE

To investigate antibody responses to a broad panel of peptides derived from human endogenous retroviruses (HERVs) among unselected patients with systemic lupus erythematosus (SLE).

METHODS

In sera obtained from 69 patients with SLE and healthy blood donors, immunoassay was used to measure levels of antibody against synthetic peptides derived from HERVs, exogenous retroviruses, and nonviral poly(amino acids).

RESULTS

Measurement by immunoassay revealed increased frequencies of antiretroviral antibodies against 2 peptides derived from the env gene of the type C-like class, which includes ERV-9 and HERV-H, and against 2 peptides from the gag region of human T lymphotropic virus type I-related endogenous sequence 1, in patients with SLE. Antibodies to 2 nonviral peptides, polyhistidine and polyproline, were also overrepresented in patient sera. In 1 patient, longitudinal data obtained over a period of 12 years indicated that the concentrations of certain antiretroviral antibodies varied according to disease activity.

CONCLUSION

Reactivity to certain type C HERV-derived antigens was found among patients with SLE. This reactivity could be explained by increased exposure to cross-reactive epitopes from essentially complete type C HERVs.

Orientation selectivity of cortical neurons during intracellular blockade of inhibition

Neurons in the primary visual cortex of the cat are selectively activated by stimuli with particular orientations. This selectivity can be disrupted by the application of antagonists of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) to a local region of the cortex. In order to determine whether inhibitory inputs are necessary for a single cortical neuron to show orientation selectivity, GABA receptors were blocked intracellularly during whole cell recording. Although the membrane potential, spontaneous activity, subfield antagonism, and directional selectivity of neurons were altered after they were perfused internally with the blocking solution, 18 out of 18 neurons remained selective for stimulus orientation. These results indicate that excitatory inputs are sufficient to generate orientation selectivity.

AASCIN strategic plan--1993-1998

A long-standing commitment to planned growth and development are essential for the AASCIN to be effective in influencing the direction of spinal cord injury (SCI) nursing. Recognizing these needs, a long-range planning initiative was supported by the Board of Directors in March, 1990. A task force was charged with the responsibility for outlining the future of the AASCIN through the development of a five-year strategic plan. The long-range planning initiative was divided into two segments. First, a Delphi Study was developed to obtain membership input into AASCIN's priorities. Once this data was collected, the Strategic Planning Task Force synthesized the results of the study and developed a five-year AASCIN strategic plan. The purpose of this article is to describe the process and content of the proposed AASCIN strategic plan. The report begins with a brief description of the Delphi Survey, which forms the foundation for the strategic plan. Since the strategic plan needs to be congruent with the organization's mission statement and goals, the organizational plan of AASCIN is presented. Lastly, a brief summary of how the organization proposes to use this strategic planning document is provided.

Persistent hypercoagulation associated with heterotopic ossification in patients with spinal cord injury long after injury has occurred

Three patients are presented with traumatic spinal cord injury (SCI) complicated by acute heterotopic ossification (HO), and concurrent deep vein thrombosis 15 months, 18 months and 22 years after SCI, accompanied by persistent hypercoagulation. The diagnosis of HO preceded deep vein thrombosis in all three patients. All were treated with etidronate disodium and therapeutic heparin followed by oral anticoagulation. As these patients were not acutely injured, the questions arose as to what predisposed them to deep vein thrombosis and when was the appropriate time to discontinue anticoagulation. Over a course of 3 years following deep vein thrombosis, these patients were monitored for evidence of hypercoagulation by D-dimer assay, plasma fibrinogen estimation, and rate of whole blood clotting by Sonoclot coagulation analyzer. The activity of acute HO was assessed by three-phase bone scan. A steady state of hypercoagulation, reflected by an increase in all three parameters, ran parallel to the extent of acute HO for the entire observation period. Moreover, hypercoagulation was persistently greater during increased acute HO activity even when the warfarin-induced prothrombin time ratio was 1.2-1.5. In addition, as acute heterotopic ossification activity decreased, the test values returned to near normal during warfarin therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Somnogenic cytokines and models concerning their effects on sleep

All the sleep-promoting substances currently identified also have other biological activities. Despite years of effort, a single specific central nervous system sleep center has not been described. These observations led us to propose a biochemical model of a sleep activational system in which the effects of several sleep factors are integrated into a regulatory scheme. These sleep factors interact by altering the metabolism, production, or activity of each other and thereby result in multiple feedback loops. This web of interactions leads to sleep stability in that minor challenges to the system will not greatly alter sleep. The system, however, is responsive to strong perturbations, such as sleep deprivation and infectious disease. The sleep-promoting effects of cytokines and their interactions with prostaglandins and the neuroendocrine system are used to illustrate the functioning of a part of the sleep activational system under normal conditions and during infectious disease. Although the actions of individuals sleep factors are not specific to sleep, their interactions at various levels of the neuraxis can mediate a specific sleep response. Such a system would also be responsive to the autonomic and environmental parameters that alter sleep.

Ischemia-induced neuronal cell death, calcium accumulation, and glial response in the hippocampus of the Mongolian gerbil and protection by propentofylline (HWA 285)

The localization and timing of cellular calcium loading and glial cell reaction in relation to selective death of hippocampal neurons was studied in Mongolian gerbils following transient forebrain ischemia. Two days after a 5-min period of ischemia, heavy calcium staining was histochemically demonstrated in circumscribed groups of nerve cells, located in the transition zone between the CA1 and CA3 areas. This preceded complete neuronal cell death that was quantitatively assessed by measuring the intensity of Nissl staining. After a 12-min period of ischemia, extensive calcium loading was observed in conjunction with severe neuronal damage throughout the CA1 region as well in the dorsal nuclei of the thalamus. The extent of calcium staining decreased with time and was not seen at stages later than 7 days. Already at 2 days after a 5-min period of ischemia, a strong increase of glial fibrillary acidic protein immunoreactivity was seen. This indicates a marked and early hypertrophy of astrocytes that was not accompanied by an obvious proliferation. Neither the astrocytic response nor the neuronal calcium accumulation were observed in gerbils pretreated with propentofylline, HWA 285 (10 mg/kg, i.p.) 15 min before bilateral carotid artery occlusion. Also, the decrease of Nissl staining in the CA1 area after 5 and 12 min of ischemia was considerably less pronounced and did not significantly differ from sham-operated controls.

Effect of partial versus complete pancreatic denervation on pancreatic secretion

The aim of this study is to compare the effect of various stimuli on pancreatic secretion in two groups of dogs, one undergoing interruption of the cholinergic and adrenergic branches to the pancreas (long arc reflexes), and the second group undergoing total denervation of the pancreas by its isolation from stomach and duodenum (short arc reflexes). Stimulation of pancreatic secretion was accomplished by (a) hormonal, by i.v. secretin and CCK/PZ and (b) reflex stimulation by intraduodenal administration of fat (Na oleate) or amino acids (Aminosyn). After a few weeks of collected data in stimulated controls, the dogs were divided into two groups: (A) Four dogs underwent proximal truncal vagotomy, celiac ganglionectomy, and stripping of the common hepatic and gastroduodenal arteries for 2-3 cm. (B) Four dogs underwent the same procedures, but in addition the pancreas was dissected away from its vascular and nervous attachments to the duodenal wall and pyloric region, as well as from its mesenteric and peritoneal attachments. All animals were then tested with secretin, Cholecystokinin/pancreozymin (CCK/PZ), intraduodenal fat, and intraduodenal amino acids. The data obtained indicate that secretion of pancreatic bicarbonate is dependent on intact local duodeno-pancreatic nervous reflexes. Fat and amino acids stimulate the secretion of bicarbonate only when the attachments of the pancreas to the stomach and duodenum are intact. Stimulation by secretion or CCK, being humoral-hormonal mediators, appears not to be affected by the local denervation.

The morphological changes of the pancreas in hypovolemic shock and the effect of pretreatment with steroids

Previous reports from this laboratory have described the effect of hypovolemic shock of varying duration on the exocrine function of the pancreas, and the ability of steroids to reverse the inhibition of secretion observed. This report is a study of pancreatic morphology in prolonged hypovolemia, as well as the effect of steroid pretreatment on the pathology observed. Twelve mongrel dogs were divided into two groups, one with and one without steroid pretreatment. The animals were bled until at least 30-35% of their blood had been withdrawn, or until mean blood pressure (BP) dropped to around 60 mmHg. When BP dropped to 80-90% mmHg, six animals received intravenous (i.v.) prednisolone in 50 cc of 0.9% NaCl, at the rate of 10 cc/min, for a dosage of 30 mg/kg. Of the twelve dogs, six were exposed to 120 min of hypovolemia, and six to 180 min. At the end of the observed hypovolemic period, the blood withdrawn was quickly retransfused. After an hour of recovery, the animals were killed and their pancreases removed. The pancreases were weighed, fixed and examined by light microscopy. Three pancreases were obtained as control from animals not subjected to shock or steroids. The steroid-treated animals displayed an insignificant (5%) increase in pancreatic weight following prolonged hypovolemia. Untreated canine pancreases, on the other hand, showed a significant weight gain (37%, P less than 0.001) after 3 h of hypovolemia. Microscopically, the untreated group revealed marked interstitial edema, hemorrhage and inflammation, as well as focal acinar cell necrosis and fat necrosis, while in the steroid group only very mild edema and inflammatory changes were seen. This study indicates a beneficial effect of steroids on the morphological changes seen in shock-induced pancreatitis in canines and a possible use in the therapy of acute pancreatitis in man.

The effect of hypovolemic shock on pancreatic secretion

A vascular pathogenesis of pancreatitis has been postulated in diabetics, the aged, Ortner's Syndrome, and various low-flow states. This report studies canine pancreatic secretion in a preparation of hypovolemic shock produced by controlled hemorrhage maintained for varying durations. Pancreatic secretion was collected by cannulation of the main pancreatic duct in anesthetized dogs. Secretin was administered by continuous intravenous (i.v.) infusion of 4 U/kg/h. Four 15-min samples of pancreatic juice were collected. Then the dogs were bled by arterial line withdrawing 25-30% of total blood volume or until the mean blood pressure dropped to about 60 mmHg. Blood was collected in heparinized containers for reinfusion. Blood samples for amylase and 15-min samples of pancreatic juice for volume, bicarbonate, and enzymes were obtained during hypovolemia as well as during and following restoration of the blood volume. Hypovolemia induced significant decreases in pancreatic flow, bicarbonate and amylase secretion, parameters which increased after reinfusion but never returned to pre-shock levels. Increasing the period of hypovolemia increased the inhibition of pancreatic flow, increased blood amylase elevation, and resulted in visible pancreatic edema. We conclude that pancreatic secretion is diminished by hypovolemia, that this is initially reversible when hypovolemia is brief, but that the disturbance of function progresses to inflammatory pathology when hypovolemia is prolonged.

The effect of steroid administration on pancreatic secretion during and after hypovolemic shock

In a previous report from this laboratory, 1 h of hypovolemia induced a significant decrease in pancreatic flow, bicarbonate and enzyme secretion. These parameters recover after restoration of blood volume, but never return to pre-shock levels. Furthermore, increasing the period of hypovolemia produced further decreases in pancreatic flow and bicarbonate secretion only. Enzyme secretion, however, rose significantly, probably due to leakage of protein through damaged cell membranes. Prolonged hypovolemia was also accompanied by visible edema. This model of secretory changes induced by fixed periods of hypovolemic shock is ideal to study the effect of steroids on secretion and to assess its possible cytoprotective properties against early induced ischemia pancreatic pathology. Pancreatic secretion was collected by cannulation of the main pancreatic duct in 12 anesthetized dogs. Secretin was administered by continuous intravenous (i.v.) infusion at 4 U/kg/h. Four 15-min samples of pancreatic juice were collected. Then the dogs were bled, withdrawing 25-30% of total blood volume or until the mean blood pressure dropped to about 60 mmHg. At this point, 30 mg/kg of methyl prednisolone were given in 50 cm3 of NaCl i.v. to six animals. Blood samples for amylase and 15-min collections of pancreatic juice for volume, bicarbonate and enzymes were obtained during hypovolemia, as well as during and following the restoration of blood volume. The responses of the two groups differed as follows: (1) Instead of the increase in protein enzyme secretion seen in the non-steroid group with increased duration of hypovolemia, steroid-treated dogs displayed a significant decrease in protein output.(ABSTRACT TRUNCATED AT 250 WORDS)