Macrophage migration inhibitory factor has a MHC class I-like motif and function.

Macrophage migration inhibitory factor (MIF) is found in immune-privileged sites and inhibits cytotoxicity mediated by CD3-ve lymphokine-activated killer cells (LAK). The mechanism by which MIF attenuates LAK cytotoxicity is unknown. We provide evidence that MIF has a major histocompatibility complex (MHC) class I-like motif. A monoclonal antibody (OX18) that binds a conserved region of rat MHC class I proteins binds native MIF. Anti-MIF polyclonal antibodies bind MHC class I. Epitope mapping suggests OX18 binds a loop of MHC class I bound by several receptors for MHC class I. A sequence (PRPEG) within the proposed OX18-binding site on MHC class I exists with a short insertion in MIF. OX18 does not bind MIF that is denatured by SDS-PAGE. This suggests the OX18 epitope is dependent on higher order structure in MIF. Interestingly, MIF inhibits binding of tetramers of MHC class I (H2D(b)) to LAK cells, suggesting it may bind to receptors for MHC class I. MIF may be an example where small regions of MHC class I are used by endogenous and viral proteins to control cytotoxicity mediated by immune cells.

Regulation of CD8 expression in mast cells by exogenous or endogenous nitric oxide.

We recently reported a novel CD8 molecule on rat alveolar macrophages and peritoneal mast cells (PMC). However, little is known about the regulation of CD8 expression and function on these cells. We investigated the regulation of CD8 expression on PMC by NO, because NO can regulate inflammatory responses and also because anti-CD8 Ab stimulates inducible NO synthase and NO production by PMC and alveolar macrophages. Ligation of CD8alpha on PMC with Ab (OX8) induced CD8alpha mRNA expression after 3-6 h, and flow cytometry demonstrated that OX8 treatment increased CD8alpha protein expression compared with PMC treated with isotype control IgG1. To test whether NO mediates the up-regulation of CD8alpha, we used the NO donor S-nitrosoglutathione (500 microM) and NO synthase inhibitors (N(G)-monomethyl-L-arginine and N(G)-nitro-L-arginine methyl ester; 100 microM). S-nitrosoglutathione up-regulated both mRNA and protein expression of CD8alpha in PMC compared with that in sham-treated cells, while NO synthase inhibitors down-regulated OX8 Ab-induced CD8alpha expression. To investigate how NO regulates CD8 expression on PMC, we examined the cGMP-dependent pathway using 8-bromo-cGMP (2 mM) and the guanylate cyclase inhibitor, 1H-oxadiazoloquinoxalin-1-one (20 microM). 8-Bromo-cGMP up-regulated CD8 expression, whereas 1H-oxadiazoloquinoxalin-1-one down-regulated its expression. Thus, ligation of CD8 up-regulates CD8 expression on PMC, a response mediated at least in part by NO through a cGMP-dependent pathway. The significance of this up-regulation of CD8alpha on mast cells (MC) is unclear, but since ligation of CD8 on MC with OX8 Ab can alter gene expression and mediator secretion, up-regulation of CD8 may enhance the MC response to natural ligation of this novel form of CD8.

Inhibition of allergic inflammation by C-terminal peptides of the prohormone submandibular rat 1 (SMR-1).

BACKGROUND: The C-terminal of the prohormone submandibular rat 1 protein (SMR-1) contains several small peptides that reduce the severity of allergic inflammation and septic shock, and are part of the cervical sympathetic trunk-submandibular gland (SMG) axis of neuroendocrine immunology. These peptides include the heptapeptide, submandibular gland peptide-T and the tripeptide FEG. The D-isomeric form of this tripeptide, feG, which is active when administered orally, reduces LPS-provoked leukocyte rolling on mesenteric venules and influx of inflammatory cells into the peritoneum and intestinal muscle. METHODS: To investigate the mechanism of action of these peptides, the influx of inflammatory molecules into the airways, and several properties of human neutrophils were examined. RESULTS: Oral feG (1 mg/kg) inhibited the influx of inflammatory cells into the airways lumen of allergen challenged, sensitized Brown Norway rats. This inhibition occurred whether feG was given 30 min prior to 6 h post allergen challenge. Moreover, feG in picomolar to nanomolar concentrations inhibited PAF elicited chemotaxis by 30-40%, but the peptides did not affect superoxide production or phagocytosis by neutrophils. feG reduced PAF-stimulated expression of CD11b. CONCLUSIONS: feG may exert its anti-inflammatory effects by modulating the expression and functions of beta(2) integrins. The CST-SMG axis may be a major neuroendocrine pathway that modulates allergic asthma and other inflammatory responses.

Redundancy or cell-type-specific regulation? Tumour necrosis factor in alveolar macrophages and mast cells.

Tumour necrosis factor (TNF) is an important inflammatory cytokine produced by several cell types. To test the hypothesis that there is cell-type-specific regulation and not redundancy of TNF production, we investigated its production by alveolar macrophages (AM) and peritoneal mast cells (PMC). Cell lysates of freshly isolated AM and PMC contained 9 +/- 3 pg and 57 +/- 17 pg of TNF/10(6) cells, respectively. Furthermore, unstimulated PMC expressed 4 x 10(3)-fold more attomols of TNF mRNA/microg total RNA compared with AM. These data may explain in part the greater TNF-dependent cytotoxicity of PMC. Furthermore, fixed PMC showed significantly higher TNF-dependent cytotoxic activity than AM (sevenfold), suggesting that PMC express more membrane TNF than AM. Although AM and PMC contain different amounts of TNF, antigen stimulation caused a similar release of TNF from sensitized rats. Interferon (IFN)-gamma, respectively, stimulated and inhibited AM and PMC TNF-dependent cytotoxicity whereas lipopolysaccharide (LPS) significantly stimulated TNF-dependent cytotoxicity in both cell types. However, TNF released (AM 400-fold and PMC threefold) and TNF mRNA expression, as measured by competitive reverse transcription-polymerase chain reaction (AM 7 x 10(3)-fold and PMC twofold), were considerably greater in LPS-stimulated AM than PMC. Our data indicate that TNF is differentially expressed in these two cell types and that its production is dependent on the nature of the stimulus. These data provide vital basis in experimental approaches aimed at modulating the effect of TNF in airway disease conditions involving both AM and mast cells.

Reverse transcriptase in situ polymerase chain reaction for gene expression in rat mast cells and macrophages.

Direct reverse transcriptase in situ polymerase chain reaction (RT-in situ PCR) of selected mRNA expression in rat mast cells (MC) and alveolar macrophages (AM) was optimized. Rat peritoneal mast cells (PMC), rat cultured mast cells (RCMC), rat bronchoalveolar lavage cells (BALC) or rat cultured alveolar macrophages (NR8383) were studied for the detection of mRNA for beta-actin, TNF-alpha and/or CD8alpha. Each type of cell has unique optimal conditions for RT-in situ PCR. The following parameters were carefully evaluated for optimization: protease digestion, DNAse digestion, heparinase digestion, RT, PCR cycle number and signal development with chromagen. Heparinase digestion was required for PMC mRNA detection because they contain large amounts of heparin proteoglycan, which is a potent inhibitor of RT and Taq polymerase enzymes. Only a few PCR cycles were needed to produce a cytoplasmic signal for mRNA transcripts in RCMC, whereas other types of cells (PMC, BALC and NR8383) needed at least 20 cycles for mRNA detection. The mRNA signal in PMC was localized to the perinuclear region, whereas mRNA in other cell types (RCMC, BALC and NR8383) were detected throughout the cytoplasm. Furthermore, modified Southern blot analysis for TNF-alpha in RCMC treated with RT-in situ PCR demonstrated the specificity of amplification product. The modified and optimized protocols for this procedure were successfully applied to detect and localize several mRNA transcripts in rat MC and AM. The approach is valuable and can be used to further study selected gene expression in these and other cell types.

IFN-gamma potentiates the release of TNF-alpha and MIP-1alpha by alveolar macrophages during allergic reactions.

Viral infections play an important role in the exacerbation of asthma. The production of interferons (IFNs) is well known to limit viral spread, but IFN-gamma can also prime alveolar macrophages to release more inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-1alpha (MIP-1alpha). Given the importance of these cytokines, we have investigated the effect of IFN-gamma on their release by alveolar macrophages during stimulation by immunoglobulin (Ig)E/anti-IgE. Alveolar macrophages from normal or Nippostrongylus brasiliensis-infected rats, the latter having increased numbers of low-affinity receptors for IgE (Fcepsilon RII) on their alveolar macrophages, were treated with IgE for 2 h and stimulated with anti-IgE for 18 h. The increase of TNF-alpha release (153 +/- 48 pg/10(6) cells) by IgE/anti-IgE occurred only with alveolar macrophages from infected rats. The messenger RNA level for TNF-alpha in rat alveolar macrophages was also increased by stimulation with IgE/anti-IgE. Treatment with IFN-gamma prior to stimulation with IgE/anti-IgE showed a time- and concentration-dependent increase of TNF-alpha release. Interestingly, IgE/anti-IgE treatment did not stimulate the release of MIP-1alpha (15 +/- 5 pg/10(6) cells), but IFN-gamma treatment alone and with IgE /anti-IgE significantly increased and potentiated MIP-1alpha release (98 +/- 40 pg/10(6) cells) by alveolar macrophages, respectively. These results suggest that IFN-gamma produced at times such as during viral infections primes alveolar macrophages for enhanced release of inflammatory mediators during allergic reactions, thereby contributing to the inflammatory process.

AICPA standard aids in detecting risk factors for fraud. American Institute of Certified Public Accountants.

The American Institute of Certified Public Accountants' Statement on Auditing Standards (SAS) No. 82, Consideration of Fraud in a Financial Statement Audit, requires independent auditors to obtain reasonable assurance that financial statements are free of material mis-statements caused by error or fraud. SAS No. 82 provides guidance for independent auditors to use to help detect and document risk factors related to potential fraud. But while SAS No. 82 suggests how auditors should assess the potential for fraud, it does not expand their detection responsibility. Accordingly, financial managers should discuss thoroughly with auditors the scope and focus of an audit as a means to further their compliance efforts.

Applying new AICPA accounting rules on special reports.

Two new standards on agreed-upon procedures, issued by the American Institute of Certified Public Accountants, provide healthcare organizations and associated decision makers with new flexibility in acquiring professional accounting services. Effective January 1, 1996, these procedures allow organizations to target the type and volume of services performed by accountants and potentially avoid the time and expense involved in completing a full financial statement audit. As with any other accounting engagement, both the healthcare organization and the accounting firm need to establish what procedures will be conducted, who will be allowed to use the resulting report, and how the procedures will be conducted.

Segment 4 (the quadrate lobe): a barometer of cirrhotic liver disease at US.

PURPOSE: To evaluate the dimensions of segment 4 of the liver in patients with cirrhosis by using ultrasonography (US). MATERIALS AND METHODS: The transverse diameter of segment 4 was measured in 125 control subjects without liver disease and 167 patients with cirrhosis. The size of segment 4 was measured on oblique subcostal US scans obtained between the left wall of the gallbladder (or the main fissure after cholecystectomy) and the ascending or umbilical portion of the left portal vein at the point where it gives rise to the branch to segment 4. RESULTS: In the control subject group, the mean diameter of segment 4 was 43 mm +/- 8 (standard deviation). In the patient group, the mean diameter of segment 4 was 28 mm +/- 9. The cause or severity of cirrhosis had no influence on the size of segment 4. CONCLUSION: A decreased diameter of segment 4 may be a helpful adjunct sign of cirrhosis in the US investigation of chronic liver disease.

Evaluation of gastric emptying function in clinical practice.

In this retrospective analysis, we compared different methods to evaluate gastric emptying function, aiming to improve the sensitivity and the clinical availability of our diagnostic testing. In the first study, we compared, in 72 patients clinically suspected of gastroparesis, the emptying of a meal containing two solid nutrients with different disintegration rates: 111In-labeled scrambled eggs and 99Tc-labeled liver cubes. Gastric emptying of 111In-labeled egg was delayed in 12 of our patients and the evacuation of the 99Tc-labeled liver was prolonged in 19 patients. The choice of the nutrient was not important for the identification of diabetic gastroparesis (43% vs 57%; NS), but it was determinant in the case of patients suspected of idiopathic gastroparesis (12% were positive with the egg and 25% with the liver; P < 0.05). In the second study, we compared two different diagnostic methods in 46 patients: a simple radiological detection of the gastric emptying of radiopaque pellets, and the scintigraphic emptying of a solid meal containing 99Tc-labeled liver cubes. Both tests correlated perfectly in 78% of our patients. In 15% of the population (six of these seven patients were diabetics suspected of gastroparesis) the scintigraphic method was normal, while the evacuation of radiopaque pellets was delayed. For clinical purposes, we therefore propose: (1) the scintigraphic method should use liver rather than egg as a radiolabeled tracer in order to improve the sensitivity of the test for detection of gastroparesis; and (2) the radiological detection of radiopaque markers is a reliable and convenient method for the detection of gastroparesis in clinical practice. It is possibly more sensitive than scintigraphy.

Clinical impact of contrast-enhanced MR imaging reports in patients with previous lumbar disk surgery.

OBJECTIVE: We wanted to assess the clinical impact of the reports of contrast-enhanced MR imaging on the decision to repeat surgery and on the results of repeat surgery in patients with previous lumbar disk surgery. SUBJECTS AND METHODS: We interviewed 257 patients who had undergone lumbar disk surgery and who showed symptoms suggesting persistent or new disk herniation. We conducted our interviews 6-18 months after patients had undergone contrast-enhanced MR imaging. We then correlated patient outcome with original MR findings. RESULTS: Fifty-two patients underwent new surgical procedures after their MR examination. Findings of disk herniation on MR images were associated with a significantly greater frequency of repeat surgery. The size of main herniation seen on MR images was also a significant variable. Patients with Worker's Compensation Insurance files had significantly worse prognoses: Only two (8%) of 26 of these patients reported 50% improvement 1 year after repeat surgery. However, only 6 (23%) of 26 non-Worker's Compensation patients reported 50% improvement 1 year after surgery. CONCLUSION: Despite its documented high anatomic accuracy, the clinical usefulness of enhanced MR imaging for patients with previous lumbar disk surgery needs further evaluation. In our series, findings of disk herniations on enhanced MR examinations were associated with a greater frequency of repeat surgery, but such surgery relieved symptoms in few patients. The influence of enhanced MR imaging on the decision for repeat surgery and on the type of surgery may be misleading. Selection criteria for repeat surgery need to be reassessed using rigorous outcome research protocols.

Bronchogenic cyst of the right hemidiaphragm.

A rare case of bronchogenic cyst of the right hemidiaphragm is reported. The literature is reviewed briefly. Clinical presentation, diagnosis, and treatment of this entity are discussed further.

Focal sparing of liver parenchyma in steatosis: role of the gallbladder and its vessels.

The purpose of this study was to determine the prevalence and localization of focal areas of sparing in a population of patients with fatty infiltration (steatosis) of the liver. We also sought to determine if the blood supply of the gallbladder has an effect on fatty infiltration of the liver adjacent to it. We studied 290 patients with sonographic signs of fatty infiltration of the liver with gray scale sonography. In 58 of the patients, the gallbladder had been removed previously. A zone of focal sparing was found in 67% of patients with liver steatosis (78% in patients with an intact gallbladder versus 33% in patients with previous cholecystectomy). In patients with an intact gallbladder, segments 4 and 5 were spared most often. These segments were rarely spared in patients with previous cholecystectomy. Other sites of focal sparing were observed with the same frequency in the two groups. We conclude that focal sparing occurs frequently in patients with liver steatosis, especially in segments 4 and 5. When the gallbladder is absent, areas of focal sparing are less frequent, and they rarely involve segments 4 and 5. This suggests that the blood supply of the gallbladder plays a role in the distribution of the fat in the adjacent liver. Focal sparing might serve as an additional sign in the diagnosis of steatosis of the liver, especially in patients with an intact gallbladder.

[Role of extracorporeal shock wave lithotripsy in the treatment of common bile duct and intrahepatic calculi]. / Place de la lithotripsie extracorporelle par ondes de choc dans le traitement des calculs cholédociens et intrahépatiques.

The management of intrahepatic and common bile duct stones has been modified by the advent of endoscopic sphincterotomy and percutaneous extraction through a T-tube tract or transhepatic access. Occasionally, nonoperative extraction is incomplete. The use of extracorporeal lithotripsy is reviewed in this setting. From May 1990 to February 1994, 18 patients (age 68.4 +/- 4.6 years) were treated by extracorporeal shockwave lithotripsy combined with endoscopic sphincterotomy and retrograde extraction or percutaneous approach. 72% of patients had previously undergone a cholecystectomy and 44% exploration of the common duct. Patients were submitted to 1.56 +/- 0.17 session of lithotripsy (5.546 +/- 701 shockwaves). Hospital stay was 19.5 +/- 3.3 days. After the lithotripsy, 1.17 +/- 0.19 endoscopic or percutaneous procedures per patient were necessary to clear the biliary tract. Seventy-eight percent of patients became stone-free. The five failures were treated by endobiliary prosthesis (n = 4) or cholecystectomy and bile duct exploration (n = 1). Lithotripsy in association with the usual therapeutic modalities contributes to clearing the bile duct from stones and avoids surgery in the majority of patients. A multidisciplinary approach is necessary in order to obtain those results.

Liver angiomyolipoma: classic and unusual presentations.

Two cases of liver angiomyolipoma (AML) are presented. The first case has the classical imaging findings previously reported. The second case has no fat content on the various imaging modalities. AML should probably be included in the differential diagnosis of any hypervascular lesion of the liver. Preoperative diagnosis with core biopsy is possible.

Postoperative changes, complications, and recurrent disease after Whipple's operation: CT features.

Whipple's operation consists of resection of the pancreatic head and duodenum, followed by pancreaticojejunostomy, choledochojejunostomy, and gastrojejunostomy or duodenojejunostomy. Indications include neoplasms of the periampullary region, symptomatic chronic pancreatitis, and, occasionally, trauma CT is useful in diagnosing postoperative complications and in detecting disease recurrence during long-term follow-up. This complex surgical procedure causes alterations of the normal anatomy, which may lead to difficulty interpreting images. Familiarity with the appearance of postoperative changes and common complications and with patterns of disease recurrence is a prerequisite to accurate interpretation of CT scans in these patients.

Air in the portal vein: sonographic and Doppler manifestations.

Three patients with portal venous gas (one with radiographic and computed tomographic findings) had similar sonographic and Doppler patterns in the portal vein (PV). These patterns consisted of hyperechogenic foci moving within the lumen of the PV, producing sharp bidirectional spikes superimposed on the usual Doppler tracing of the PV. An injection of 0.25-0.50 cm3 of air, oxygen, nitrogen, and carbon dioxide into the jejunal vein of nine dogs yielded identical portal venous sonographic and Doppler patterns. In addition, the liver parenchyma of the dogs became hyperechogenic after the injection of gas. Gas in the PV is accompanied by the following signs: echogenic, moving foci within the lumen of the PV; sharp spikes on Doppler spectral display; and hyperechogenic foci within the liver parenchyma.

Evaluation of complex congenital ventricular anomalies with magnetic resonance imaging.

Complex ventricular anomalies are frequently associated with abnormalities of thoracic and abdominal situs, arterioventricular connection, and venous connection. The definition of all components of these anomalies is difficult to accomplish with imaging techniques. This study compared the effectiveness of electrocardiographic (ECG) gated spin-echo magnetic resonance imaging (MRI) with cardiac angiography for the evaluation of all components of central cardiovascular anatomy in patients with the clinical diagnosis of single or common ventricle or complete atrioventricular (AV) septal (canal) defect. MRI studies and angiograms of 29 patients were evaluated independently. A sequential approach was used to define cardiac anatomy assessing nine anatomic features in each patient. MRI provided 261 observations and angiography provided 209 observations. In the mutual 209 observations, only 17 discrepancies were found. Comparison of MRI and angiography in individual cases showed that MRI was as effective as angiography in the depiction of ventricular anomalies, including determination of morphology and evaluation of the size of the ventricles, the orientation of the ventricular septum relative to the AV valves, as well as the origins and spatial relationships of the great arteries. MRI was more informative for the determination of thoracic and abdominal situs and systemic and pulmonary venoatrial connections, but was not as effective for the evaluation of semilunar valves. Thus MRI provides complete evaluation of central cardiovascular anatomy and is effective in the anatomic assessment of most components of complex ventricular anomalies.

Temporal lobe abnormalities in panic disorder: an MRI study.

Brain mapping studies have shown abnormal changes in cerebral blood volume and oxygen consumption, or other neurophysiological abnormalities, in panic disorder (PD) patients. Because of these intriguing reports, we decided to assess the neuroanatomical aspects of patients with PD using magnetic resonance imaging (MRI). We included 31 consecutive cases with a diagnosis of PD according to the DSM-III criteria, and 20 controls. All subjects had to be right-handed and between 20 and 40 years of age. The usual exclusion criteria were applied. We carried out the MRI tests with a General Electric Signa Machine operating at 1.5 Tesla. Over 100 images were obtained per patient with an emphasis on assessing temporal lobe. There were no significant differences in age, gender, or weight between the patients and controls. We found a statistically significant higher number of abnormalities in PD patients (40%), as compared with the controls (10%). The most striking findings were focal abnormalities in the temporal lobes: areas of abnormal signal activity, and asymmetric atrophy of the temporal lobe occurred mostly on the right side. These results implicated the limbic system and may prove to be of particular relevance in panic and phobic disorders. However, the significance of our findings remains unknown and challenging. Further MRI studies in PD will be required for a better understanding of the illness.