Functional heterogeneity of mutant rhodopsins responsible for autosomal dominant retinitis pigmentosa

Thirteen mutant rhodopsins responsible for autosomal dominant retinitis pigmentosa (ADRP) have been produced by transfection of cloned cDNA into tissue culture cells. Three mutants [class I: Phe-45----Leu, Gln-344----termination (deletion of C-terminal positions 344-348), and Pro-347----Leu] resemble wild-type rhodopsin in yield, regenerability with 11-cis-retinal, and plasma membrane localization. Ten mutants [class II: Thr-17----Met, Pro-23----His, Thr-58----Arg, Val-87----Asp, Gly-89----Asp, Gly-106----Trp, Arg-135----Leu, Arg-135----Trp, Tyr-178----Cys, and Asp-190----Gly] accumulate to significantly lower levels, regenerate with 11-cis-retinal variably or not at all, and are transported inefficiently to the plasma membrane, remaining primarily in the endoplasmic reticulum. These data suggest that there are at least two distinct biochemical defects associated with different rhodopsin mutants in ADRP.

Amyloid vs FDG-PET in the differential diagnosis of AD and FTLD

OBJECTIVE

To compare the diagnostic performance of PET with the amyloid ligand Pittsburgh compound B (PiB-PET) to fluorodeoxyglucose (FDG-PET) in discriminating between Alzheimer disease (AD) and frontotemporal lobar degeneration (FTLD).

METHODS

Patients meeting clinical criteria for AD (n = 62) and FTLD (n = 45) underwent PiB and FDG-PET. PiB scans were classified as positive or negative by 2 visual raters blinded to clinical diagnosis, and using a quantitative threshold derived from controls (n = 25). FDG scans were visually rated as consistent with AD or FTLD, and quantitatively classified based on the region of lowest metabolism relative to controls.

RESULTS

PiB visual reads had a higher sensitivity for AD (89.5% average between raters) than FDG visual reads (77.5%) with similar specificity (PiB 83%, FDG 84%). When scans were classified quantitatively, PiB had higher sensitivity (89% vs 73%) while FDG had higher specificity (83% vs 98%). On receiver operating characteristic analysis, areas under the curve for PiB (0.888) and FDG (0.910) were similar. Interrater agreement was higher for PiB (κ = 0.96) than FDG (κ = 0.72), as was agreement between visual and quantitative classification (PiB κ = 0.88-0.92; FDG κ = 0.64-0.68). In patients with known histopathology, overall classification accuracy (2 visual and 1 quantitative classification per patient) was 97% for PiB (n = 12 patients) and 87% for FDG (n = 10).

CONCLUSIONS

PiB and FDG showed similar accuracy in discriminating AD and FTLD. PiB was more sensitive when interpreted qualitatively or quantitatively. FDG was more specific, but only when scans were classified quantitatively. PiB slightly outperformed FDG in patients with known histopathology.

Characterization of a transformed rat retinal ganglion cell line

The purpose of the present study was to establish a rat retinal ganglion cell line by transformation of rat retinal cells. For this investigation, retinal cells were isolated from postnatal day 1 (PN1) rats and transformed with the psi2 E1A virus. In order to isolate retinal ganglion cells (RGC), single cell clones were chosen at random from the transformed cells. Expression of Thy-1 (a marker for RGC), glial fibrillary acidic protein (GFAP, a positive marker for Muller cells), HPC-1/syntaxin (a marker for amacrine cells), 8A1 (a marker for horizontal and ganglion cells) and neurotrophins was studied using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoblotting and immunocytochemistry. One of the retinal cell clones, designated RGC-5, was positive for Thy-1, Brn-3C, Neuritin, NMDA receptor, GABA-B receptor, and synaptophysin expression and negative for GFAP, HPC-1, and 8A1, suggesting that it represented a putative RGC clone. The results of RT-PCR analysis were confirmed by immunocytochemistry for Thy-1 and GFAP. Upon further characterization by immunoblotting, the RGC-5 clone was positive for Thy-1, negative for GFAP, 8A1 and syntaxin. RGC 5 cells were also positive for the expression of neurotrophins and their cognate receptors. To establish the physiological relevance of RGC-5, the effects of serum/trophic factor deprivation and glutamate toxicity were analyzed to determine if these cells would undergo apoptosis. The protective effects of neurotrophins on RGC-5 after serum deprivation was also investigated. Apoptosis was studied by terminal deoxynucleotidyl transferase-mediated fluoresceinated dUTP nick end labeling (TUNEL). Serum deprivation resulted in apoptosis and supplementation with both BDNF and NT-4 in the growth media, protected the RGC-5 cells from undergoing apoptosis. On differentiation with succinyl concanavalin A (sConA), RGC-5 cells became sensitive to glutamate toxicity, which could be reversed by inclusion of ciplizone (MK801). In conclusion, a transformed rat retinal cell line, RGC-5, has certain characteristics of retinal ganglion cells based on Thy-1 and Brn-3C expression and its sensitivity to glutamate excitotoxicity and neurotrophin withdrawal. These cells may be valuable in understanding of retinal ganglion cell biology and physiology including in vitro manipulations in experimental models of glaucoma.

A conserved retina-specific gene encodes a basic motif/leucine zipper domain

Using subtraction cloning, we have isolated a human cDNA, AS321, which is expressed in retina and retinoblastoma cell lines but not in any other tissue or cell line tested. AS321 mRNA is detected in all cells of neural retina, with a high level of expression in photoreceptors. The polypeptide sequence deduced from the cDNA reveals consensus phosphorylation sites for protein kinase A and proline-directed protein kinase. Its C-terminal region contains a basic motif and a leucine zipper domain similar to the DNA binding proteins of the jun and fos oncoprotein family, and it shows a strong similarity to the product of an avian retroviral oncogene, v-maf. The gene for AS321 is conserved during evolution and is expressed in vertebrate retina. We propose to name the gene NRL (neural retina leucine zipper.

A critical evaluation of laboratory tests in acute pancreatitis

An ideal laboratory test in the evaluation of a patient with acute pancreatitis (AP) should, in addition to accurately establishing the diagnosis of AP, provide early assessment of its severity and identify the etiology. None of the tests available today meet all these criteria, and presently there is no biochemical test that can be considered the "gold standard" for the diagnosis and assessment of severity of AP. In the diagnosis of AP, serum amylase and lipase remain important tests. Advantages of amylase estimation are its technical simplicity, easy availability, and high sensitivity. However, its greatest disadvantage is its low specificity. A normal amylase would usually exclude the diagnosis of AP, with the exception of AP secondary to hyperlipidemia, acute exacerbation of chronic pancreatitis, and when the estimation of amylase is delayed in the course of the disease. The major advantage of lipase is an increased sensitivity in acute alcoholic pancreatitis and in patients who initially present to the emergency room days after the onset of the disease, as lipase remains elevated longer than amylase. Although once considered to be specific for AP, nonspecific elevations of lipase have been reported in almost as many disorders as amylase, thus decreasing its specificity. Simultaneous estimation of amylase and lipase does not improve the accuracy. Other enzymes for the diagnosis of AP--pancreatic isoamylase, immunoreactive trypsin, and elastase--are more cumbersome and expensive and have no clear role in the diagnosis of AP. No enzyme assay has a predictive role in determining the severity or etiology of AP. Once the diagnosis of AP is established, daily measurements of enzymes have no value in assessing the clinical progress of the patient or ultimate prognosis and should be discouraged. A host of new serological and urinary markers have been investigated in the last few years. Their main use is in predicting the severity of AP. At present, serum C-reactive protein at 48 h is the best available laboratory marker of severity. Urinary trypsinogen activation peptides within 12-24 h of onset of AP are able to predict the severity but are not widely available. Serum interleukins 6 and 8 seem promising but remain experimental.

Pharmacologically different Na/H antiporters on the apical and basolateral surfaces of cultured porcine kidney cells (LLC-PK1)

Proximal tubule cells of the kidney contain, on their apical surface, an amiloride-sensitive Na/H antiporter that functions in Na reabsorption and proton secretion. We have investigated the localization of the antiporter in a cloned cell line of porcine renal origin, LLC-PK1/Cl4, which is often considered to be a useful model of the proximal tubule. Transport measurements were performed with differentiated monolayers grown on Nuclepore filters, permitting independent access to the apical and basolateral cell surfaces. In control experiments with LLC-PK1/Cl4 monolayers, three marker transport systems showed the expected polarity: 87% of ouabain-sensitive Rb uptake was at the basolateral surface, and 99% of Na-dependent alpha-methylglucoside transport and 93% of Na-dependent D-aspartate (L-glutamate) transport were at the apical surface. By contrast, the monolayers displayed significant Na/H antiporter activity (assayed as ethylisopropylamiloride-sensitive 22Na uptake) at both cell surfaces, with an apical uptake rate amounting to 44% and a basolateral rate amounting to 56% of the total. Significantly, the apical and basolateral antiporters could readily be distinguished from one another on the basis of ethylispropylamiloride sensitivity. The apical system had an IC50 of 13 microM, close to that reported for kidney brush border vesicle preparations, whereas the basolateral system had an IC50 of 44 nM, similar to values seen in undifferentiated LLC-PK1 cells and other cultured cell lines. The PKE20 mutant, previously selected from LLC-PK1/Cl4 on the basis of resistance to ethylisopropylamiloride, was found to overexpress the more resistant antiporter both during rapid growth and on its apical cell surface at confluence; normal amounts of the more sensitive antiporter were seen on the basolateral surface of confluent PKE20 cells. Taken together, these results suggest that there are two distinct forms of the Na/H antiporter, which are under separate genetic control.

Blood transfusion increases the risk of infection after trauma

To determine whether blood transfusion influences infection after trauma, we analyzed data on 5366 consecutive patients hospitalized for more than 2 days at eight hospitals over a 2-year period. The incidence of infection was significantly related to the mechanism of injury: penetrating injuries, 8.9%; blunt injuries, 12.9%; and low falls, 21.4%. Stepwise logistic regression analyses of infection using the variables age, sex, respiration rate in the emergency department, Glasgow Coma Scale in the emergency department, Injury Severity Score, shock (systolic blood pressure < 90 mm Hg on admission to the emergency department), and log of total amount of blood transfused during hospitalization showed that amount of blood received and Injury Severity Score were the only two variables that were significant predictors of infection across groups. Even when patients were stratified by Injury Severity Score, the infection rate increased significantly with increases in numbers of units of blood. Blood transfusion in the injured patients is an important independent statistical predictor of infection. Its contribution cannot be attributed to age, sex, or the underlying mechanism of severity of injury.

Outcomes of patients with metastatic renal cell carcinoma that do not meet eligibility criteria for clinical trials

BACKGROUND

Targeted therapies in metastatic renal cell carcinoma (mRCC) have been approved based on registration clinical trials that have strict eligibility criteria. The clinical outcomes of patients treated with targeted agents but are ineligible for trials are unknown.

PATIENTS AND METHODS

mRCC patients treated with vascular endothelial growth factor-targeted therapy were retrospectively deemed ineligible for clinical trials (according to commonly used inclusion/exclusion criteria) if they had a Karnofsky performance status (KPS) <70%, nonclear-cell histology, brain metastases, hemoglobin ≤9 g/dl, creatinine >2× the upper limit of normal, corrected calcium ≥12 mg/dl, platelet count of <100 × 10(3)/uL, or neutrophil count <1500/mm(3).

RESULTS

Overall, 768 of 2210 (35%) patients in the International Metastatic RCC Database Consortium (IMDC) were deemed ineligible for clinical trials by the above criteria. Between ineligible versus eligible patients, the response rate, median progression-free survival (PFS) and median overall survival of first-line targeted therapy were 22% versus 29% (P = 0.0005), 5.2 versus 8.6 months, and 12.5 versus 28.4 months (both P < 0.0001), respectively. Second-line PFS (if applicable) was 2.8 months in the trial ineligible versus 4.3 months in the trial eligible patients (P = 0.0039). When adjusted by the IMDC prognostic categories, the HR for death between trial ineligible and trial eligible patients was 1.55 (95% confidence interval 1.378-1.751, P < 0.0001).

CONCLUSIONS

The number of patients that are ineligible for clinical trials is substantial and their outcomes are inferior. Specific trials addressing the unmet needs of protocol ineligible patients are warranted.

Distinct clinical and metabolic deficits in PCA and AD are not related to amyloid distribution

BACKGROUND/OBJECTIVE

Patients with posterior cortical atrophy (PCA) often have Alzheimer disease (AD) at autopsy, yet are cognitively and anatomically distinct from patients with clinical AD. We sought to compare the distribution of β-amyloid and glucose metabolism in PCA and AD in vivo using Pittsburgh compound B (PiB) and FDG-PET.

METHODS

Patients with PCA (n = 12, age 57.5 ± 7.4, Mini-Mental State Examination [MMSE] 22.2 ± 5.1), AD (n = 14, age 58.8 ± 9.6, MMSE 23.8 ± 6.7), and cognitively normal controls (NC, n = 30, age 73.6 ± 6.4) underwent PiB and FDG-PET. Group differences in PiB distribution volume ratios (DVR, cerebellar reference) and FDG uptake (pons-averaged) were assessed on a voxel-wise basis and by comparing binding in regions of interest (ROIs).

RESULTS

Compared to NC, both patients with AD and patients with PCA showed diffuse PiB uptake throughout frontal, temporoparietal, and occipital cortex (p < 0.0001). There were no regional differences in PiB binding between PCA and AD even after correcting for atrophy. FDG patterns in PCA and AD were distinct: while both groups showed hypometabolism compared to NC in temporoparietal cortex and precuneus/posterior cingulate, patients with PCA further showed hypometabolism in inferior occipitotemporal cortex compared to both NC and patients with AD (p < 0.05). Patients with AD did not show areas of relative hypometabolism compared to PCA.

CONCLUSIONS

Fibrillar amyloid deposition in PCA is diffuse and similar to AD, while glucose hypometabolism extends more posteriorly into occipital cortex. Further studies are needed to determine the mechanisms of selective network degeneration in focal variants of AD.

Pancreatic pseudocysts. When and how should drainage be performed?

A better definition of a pseudocyst that clearly separates it from acute fluid collection, improvements in imaging studies, and a better understanding of the natural history of pseudocysts have changed the concepts regarding their management. The old teaching that cysts of more than 6 cm in diameter that have been present for 6 weeks should be drained is no longer true. Indications for drainage are presence of symptoms, enlargement of cyst, complications (infection, hemorrhage, rupture, and obstruction), and suspicion of malignancy. The available forms of therapy include percutaneous drainage, transendoscopic approach, and surgery. The choice of procedure of depends on a number of factors, including the general condition of the patient; size, number, and location of cysts; presence or absence of communication of the cyst with the pancreatic duct; presence or absence of infection; and suspicion of malignancy. Expertise of the radiologist and the endoscopist is also a major deciding factor in the choice of therapy. Percutaneous catheter drainage is safe and effective and should be the treatment of first choice in poor-risk patients, for immature cysts, and for infected pseudocysts. Contraindications include intracystic hemorrhage and presence of pancreatic ascites. For mature cysts, in skilled endoscopic drainage should be given the first preference. It is less invasive, less expensive, and easier to perform with better outcomes in smaller pseudocysts and pancreatic head pseudocysts. Endoscopic expertise is limited, however, and at present endoscopic drainage cannot be advocated as the procedure for general use. In the absence of endoscopic expertise, percutaneous catheter drainage is the procedure of choice. Surgical treatment has been the traditional approach and is still the preferred treatment in most centers. Multiple pseudocysts, giant pseudocysts, presence of other complications related to chronic pancreatitis in addition to pseudocyst, and suspected malignancy are best managed surgically. Surgery is also the backup management in the event that percutaneous or endoscopic drainage fails. Because radiologic diagnosis of pseudocyst may be inaccurate in 20%; it is imperative to be sure that the cystic structure is not a neoplasm before percutaneous or endoscopic drainage. There have been no prospective, randomized trials that have evaluated the results of the three major modalities of therapy (percutaneous, endoscopic, and surgical), and before one can definitely recommend percutaneous drainage or endoscopic approach as the preferred initial mode of therapy, further studies are needed.

Predictive ability of various nutritional variables for mortality in elderly people

Nutritional indices (percentage ideal body weight [IBW], serum albumin, serum transferrin, total lymphocyte count [TLC] and delayed cutaneous hypersensitivity [DH] response) were assessed in 80 consecutive patients (aged 85-100 y) within 24 h of admission to determine their predictive value for mortality. Nine patients died. Pearson correlation analysis demonstrated that death was significantly (p less than 0.05 to less than 0.01) associated with sepsis, serum albumin less than 30 g/L, TLC less than or equal to 1500 cells/mm3, and percentage IBW less than or equal to 90%. However, when serum albumin was controlled for, logit regression analyses demonstrated that the impact of other nutritional indices on death was insignificant. The effect of serum albumin remained significant (p less than 0.05 to less than 0.01) even when age and physician's diagnosis were held constant. With the logit model, serum albumin greater than or equal to 30 g/L had a sensitivity of 0.33, specificity of 0.99, and overall predictive power of 0.91. Serum albumin is thus the simplest and best single predictor of mortality and can provide early identification of elderly people at increased risk of death.

Microbial status and rumen enzyme profile of crossbred calves fed on different microbial feed additives

AIMS

To test various microbial cultures as cattle feed additives.

METHODS AND RESULTS

Four groups of newly born crossbred calves (average body weight 23.5 kg) were reared on green berseem and calf starter which was devoid of cereal grains. Milk was fed up to 8 weeks of age, starting with one tenths and gradually reducing to one twentieths of the body weight. One hundred millilitres of microbial feed additive or 100 g fermented feed was fed to the animals of group 2 (curd containing lactic acid bacteria at 10(8) cfu x ml(-1)), group 3 (Saccharomyces cerevisiae NCDC-49 at 10(6) cfu x ml(-1)) and group 4 (Lactobacillus acidophilus-15 at 10(8) cfu x ml(-1)). Group 1 served as control. The incidence and duration of diarrhoea was lower in the animals of probiotic fed groups as compared to control group. Out of three microbial feed additives, yeast feeding showed maximum suppression of diarrhoea followed by Lactobacillus and curd.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

There was no effect of probiotic feeding on the log number of cells of lactic acid bacteria, yeast and coliform bacteria in the faeces and rumen liquor at any age. The activities of carboxymethylcellulase, xylanase, beta-glucosidase, alpha-glucosidase, alpha-amylase, protease, urease and pH of the rumen liquor remained unaffected by probiotic feeding at all ages tested in this experiment.

Photo-oxidative stress down-modulates the activity of nuclear factor-kappaB via involvement of caspase-1, leading to apoptosis of photoreceptor cells

The mechanisms of photoreceptor cell death via apoptosis, in retinal dystrophies, are largely not understood. In the present report we show that visible light exposure of mouse cultured 661W photoreceptor cells at 4.5 milliwatt/cm2 caused a significant increase in oxidative damage of 661W cells, leading to apoptosis of these cells. These cells show constitutive expression of nuclear factor-kappaB (NF-kappaB), and light exposure of photoreceptor cells results in lowering of NF-kappaB levels in both the nuclear and cytosolic fractions in a time-dependent manner. Immunoblot analysis of IkappaBalpha and p50, and p65 (RelA) subunits of NF-kappaB, suggested that photo-oxidative stress results in their depletion. Immunocytochemical studies using antibody to RelA subunit of NF-kappaB further revealed the presence of this subunit constitutively both in the nucleus and cytoplasm of the 661W cells. Upon exposure to photo-oxidative stress, a depletion of the cytoplasmic and nuclear RelA subunit was observed. The depletion of NF-kappaB appears to be mediated through involvement of caspase-1. Furthermore, transfection of these cells with a dominant negative mutant IkappaBalpha greatly enhanced the kinetics of down modulation of NF-kappaB, resulting in a faster photo-oxidative stress-induced apoptosis. Taken together, these studies show that the presence of NF-kappaB RelA subunit in the nucleus is essential for protection of photoreceptor cells against apoptosis mediated by an oxidative pathway.

Endoscopic biliary drainage by nasobiliary drain or by stent placement in patients with acute cholangitis

BACKGROUND AND STUDY AIMS

Endoscopic biliary drainage is an established mode of treatment for acute cholangitis. We compared the safety and efficacy of nasobiliary drain (NBD) placement and stent placement for biliary drainage in patients with acute cholangitis.

PATIENTS AND METHODS

We recruited a total of 150 patients with severe cholangitis who required endoscopic biliary drainage. Patients were randomized to have either a 7-Fr NBD or a 7-Fr straight flap stent placed during endoscopy. Outcome measures included complications related to endoscopic retrograde cholangiopancreatography (ERCP) and the clinical outcome.

RESULTS

Of the 150 patients, 75 were randomized to the NBD group and 75 to the stent group. The most common causes of biliary obstruction were common bile duct stones (n = 102) and biliopancreatic malignancies (n = 37). The site of the biliary obstruction was predominantly found to be the lower part of common bile duct in both the NBD group (n = 58) and the stent group (n = 59). Indications for biliary drainage were: a fever of > 100.4 degrees F (n = 140), hypotension (n = 23), peritonism (n = 40), impaired consciousness (n = 29), and failure to improve with conservative management (n = 45). Biliary drainage was achieved in 147 patients. Abdominal pain, fever, jaundice, hypotension, peritonism and altered sensorium improved after a median period of 2 days in both groups. Leukocyte counts became normal after a median time of 7 days in the NBD group and 6 days in the stent group. There were no ERCP-related complications. There were no instances of displacement or kinking of an NBD, occlusion of an NBD or stent, or of stent migration. Four patients died (two in the NBD group and two in the stent group) as a result of uncontrolled cholangitis after 1, 2, 4, and 6 days of biliary drainage. The success rates of biliary drainage in cholangitis were not affected by the type of endoprosthesis used (72/74 for NBD patients vs. 71/73 for stent patients), the etiology of the biliary obstruction (110/112 for benign obstruction vs. 33/35 for malignant obstruction), or the site of the biliary obstruction (28/30 for upper common bile duct obstruction vs. 115/117 for obstruction at the lower end of common bile duct).

CONCLUSIONS

Biliary drainage by nasobiliary drain and drainage by stent are equally safe and effective treatments for patients with severe cholangitis.

Increased risk for irritable bowel syndrome after acute diverticulitis

BACKGROUND & AIMS

Individuals with diverticulosis frequently also have irritable bowel syndrome (IBS), but there are no longitudinal data to associate acute diverticulitis with subsequent IBS, functional bowel disorders, or related emotional distress. In patients with postinfectious IBS, gastrointestinal disorders cause long-term symptoms, so we investigated whether diverticulitis might lead to IBS. We compared the incidence of IBS and functional bowel and related affective disorders among patients with diverticulitis.

METHODS

We performed a retrospective study of patients followed up for an average of 6.3 years at a Veteran's Administration medical center. Patients with diverticulitis were identified based on International Classification of Diseases, 9th revision codes, selected for the analysis based on chart review (cases, n = 1102), and matched with patients without diverticulosis (controls, n = 1102). We excluded patients with prior IBS, functional bowel, or mood disorders. We then identified patients who were diagnosed with IBS or functional bowel disorders after the diverticulitis attack, and controls who developed these disorders during the study period. We also collected information on mood disorders, analyzed survival times, and calculated adjusted hazard ratios.

RESULTS

Cases were 4.7-fold more likely to be diagnosed later with IBS (95% confidence interval [CI], 1.6-14.0; P = .006), 2.4-fold more likely to be diagnosed later with a functional bowel disorder (95% CI, 1.6-3.6; P < .001), and 2.2-fold more likely to develop a mood disorder (CI, 1.4-3.5; P < .001) than controls.

CONCLUSIONS

Patients with diverticulitis could be at risk for later development of IBS and functional bowel disorders. We propose calling this disorder postdiverticulitis IBS. Diverticulitis appears to predispose patients to long-term gastrointestinal and emotional symptoms after resolution of inflammation; in this way, postdiverticulitis IBS is similar to postinfectious IBS.

Prevention of postischaemic lipid peroxidation and liver cell injury by iron chelation

Liver ischaemia was induced by cross clamping the hilar pedicle for 30 minutes in groups of rats with or without treatment with the iron chelating agent desferrioxamine (deferoxamine, DFR). The groups included eight animals each and were divided into the following treatment categories: control; ischaemia alone; ischaemia with subsequent reperfusion; ischaemia preceded by DFR, 60 mg/kg body weight; and reperfusion preceded by 20, 40, or 60 mg/kg DFR. The drug was given intravenously five minutes before either ischaemia or reperfusion. Malondialdehyde (MDA), a product of lipid peroxidation, and histopathological changes of liver tissue samples were used as indicators of hepatocellular injury. Lipid peroxidation (MDA concentration in mumol/kg liver tissue) was highest (4.76 (1.19] after ischaemia without reperfusion and less pronounced (2.87 (0.34] after reperfusion. Both concentrations, however, were significantly (p less than 0.05) higher than basal (control) values (1.78 (0.27]. At 60 mg/kg body weight, DFR treatment reduced MDA to basal or even lower concentrations in both situations (1.98 (0.08) and 1.26 (0.06), respectively) with a corresponding improvement in liver histopathology. Lower DFR doses were less protective. The data suggest that liver ischaemia is associated with free radical initiated, and apparently iron catalysed lipid peroxidation, which can be significantly decreased by iron chelation.

Limitations of the TRISS method for interhospital comparisons: a multihospital study

The value of the TRISS method for interhospital comparisons of trauma care was studied using data for 5,616 consecutive patients from three trauma centers and five community hospitals. Z-scores were used to compare mortality rates. Three limitations of the method were documented: 1) the lack of homogeneity within the patient subcategory of penetrating injuries, specifically between patients with gunshot versus stab wounds; 2) the inability of the TRISS method to predict the survival rate of patients suffering low falls; and 3) the inability of the TRISS method to account for multiple severe injuries to a single body part. Remedies to the first two of these limitations can be addressed within the present TRISS method. A remedy for the third requires a new method.

Clinical and Radiological Outcomes in Robotic-Assisted Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

The aim of this systematic review is to determine if robotic-assisted total knee arthroplasty (RATKA) results in improved clinical and radiological outcomes, and to elucidate the breadth and depth of studies conducted on this topic.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic review was conducted using 4 databases (MEDLINE, EMBASE, Cochrane, and Web of Science) to identify all clinical studies that investigate clinical or radiological outcomes using RATKA. The Critical Appraisal Skills Program checklist for cohort studies was employed for critical appraisal and evaluation of all 22 studies that met the inclusion criteria.

RESULTS

All studies reviewed determined that knee arthroplasty improved clinical outcomes. Twelve studies found statistically better clinical outcomes with RATKA compared with conventional TKA, whereas 9 studies found no difference. One study did not assess clinical outcomes. When assessing radiological outcomes, 14 studies reported that RATKA resulted in more consistent and accurate postoperative mechanical alignment, whereas 2 studies reported no difference. Six studies did not assess radiological outcomes.

CONCLUSION

Although knee arthroplasty is one of the most commonly performed orthopedic operations, the level of patient satisfaction varies. The meta-analyses conducted in our systematic review shows that RATKA results in greater improvements in postoperative Hospital for Special Surgery score and Western Ontario and McMaster Universities scores compared to conventional TKA. Furthermore, it shows that RATKA results in more accurate postoperative alignment of prostheses. These together can explain the improved postoperative outcomes. More randomized controlled trials must be conducted before this technique is integrated into routine clinical practice.

Production of bovine rhodopsin by mammalian cell lines expressing cloned cDNA: spectrophotometry and subcellular localization

Cloned cDNA encoding bovine rhodopsin has been recombined into an expression vector and cotransfected with an antibiotic resistance plasmid into cultured human embryonic kidney cells. The resulting cell lines produce 100-200 micrograms of bovine opsin per liter of saturated tissue culture medium (10(9) cells). Incubation in vitro with 11-cis retinal produces a photolabile pigment the absorbance spectrum of which is indistinguishable from that of bona fide bovine rhodopsin. Expressed rhodopsin accumulates in the plasma membrane as determined by immunoelectron microscopy.

Are immunosuppressive medications associated with decreased responses to routine immunizations? A systematic review

BACKGROUND

Long-term immunosuppressive medications are being used more commonly for a variety of medical conditions, including immune-mediated diseases and organ transplantation. While these medications are often necessary, they are associated with an increased risk of serious infections. Vaccination may be a way to prevent a variety of infections but vaccine responses among patients receiving immunosuppressive therapies have been variable.

PURPOSE

To systematically review the literature describing immune responses among patients on immunosuppressive therapies to vaccinations including influenza, pneumococcal, meningococcal, hepatitis A and B, tetanus toxoid, pertussis, varicella, and zoster.

DATA SOURCES

English language citations in the MEDLINE and EMBASE databases from 1985 to 2010.

STUDY SELECTION

Two reviewers independently screened titles and abstracts to identify prospective, controlled studies reporting pre- and post-vaccination titers of recommended vaccines in patients receiving long-term immunosuppressive therapies for full-text review.

DATA EXTRACTION

Three reviewers independently assessed study characteristics including treatment regimens and pre- and post-vaccination titers.

DATA SYNTHESIS

Of the 972 identified titles, fifteen met inclusion criteria. Ten studies assessed the effects of immunosuppressive medications on responses to influenza vaccine, four studies investigated responses following pneumococcal vaccination, and one study assessed both influenza and pneumococcal vaccination. Five of the studies that evaluated influenza vaccination showed partially diminished responses among individuals receiving immunosuppressive therapies, while one of the pneumococcal vaccine studies showed significantly decreased responses following vaccination. Patients treated with more than one immunosuppressive medication were the least likely to respond to vaccination.

LIMITATIONS

The heterogeneity of reported outcomes limits generalizeability.

CONCLUSIONS

Immunosuppressive therapy, particularly combination regimens, may blunt response to influenza and pneumococcal vaccinations. To ensure the best chance of response, immunizations should be administered prior to initiation of immunosuppressive medications whenever possible.

Evaluation of the pylorus with concurrent intraluminal pressure and EndoFLIP in patients with nausea and vomiting

BACKGROUND

Nausea and vomiting occurs in gastroparesis due to diabetes mellitus or unknown causes. The aim of this study was to compare (i) pyloric distensibility to pyloric manometric pressure in patients with nausea and vomiting and (ii) to correlate distensibility with delays in gastric emptying.

METHODS

Sleeve manometry and EndoFLIP were performed sequentially during the same endoscopy on 114 patients with nausea and vomiting (47 with diabetes mellitus and 67 with idiopathic cause) after a standardized gastric emptying study. The sleeve manometer was positioned fluoroscopically, and the EndoFLIP was placed endoscopically. Manometric pressure using a water-perfused catheter and distensibility using an EndoFLIP filled with 40 cc of saline were measured from the pylorus.

KEY RESULTS

The basal pyloric pressure was elevated (>10 mmHg) in 34 patients and was normal in 80 patients. The basal and peak pressures were similar in patient with normal and delayed gastric emptying (p > 0.05). There was a significant decrease in distensibility (8.0 ± 1.0 mm(2) /mmHg) in patients with gastric retention (>20% at 4 h) compared with patients (12.4 ± 1.4 mm(2) /mmHg) (p < 0.01) with normal gastric retention (<10%). Pressure measurements from the sleeve manometer and the EndoFLIP correlated (r = 0.29) (p < 0.002), and increased EndoFLIP balloon pressure (19.4 ± 1.4 mmHg) (p < 0.01) was associated with a severe delay in gastric emptying.

CONCLUSIONS & INFERENCES

Elevated basal pyloric pressure occurs in 42% of patients with nausea and vomiting and delayed emptying. Decreased pyloric distensibility occurs with nausea, vomiting, and delayed gastric emptying. The EndoFLIP is a useful tool in the evaluation of pyloric function in symptomatic patients.

Cardiac disease in pregnancy

OBJECTIVES

To evaluate the maternal and fetal outcome of pregnancies complicated by cardiac disease in a developing country.

METHODS

A retrospective analysis was carried out of 207 pregnancies in women with cardiac disease who delivered at >or=28 weeks of gestation from June 1994 through December 2000 at a tertiary care center.

RESULTS

Rheumatic heart disease (n=183, 88%) with isolated mitral stenosis (n=71) was the predominant cardiac problem. Septal defects were the most common form of congenital heart disease (n=24). In 28 (13.52%) women, the diagnosis of cardiac disease was made during pregnancy. Cardiac complications were noted in 62 (29.95%) and fetal complications in 42 (20.28%) pregnancies. Patients in NYHA class I/II (n=175, 84.54%) had fewer maternal complications and their babies had a higher birth weight than those in NYHA class III/IV (n=32, 15.45%). Cardiac intervention was performed prior to pregnancy in 111 (60.65%) patients with rheumatic heart disease: PTMC/CMV in 73 and valve replacement (VR) in 38. Maternal and fetal outcome was better in patients with prosthetic valves (n=38) and the majority (97.4%) of them remained in NYHA class I/II. Cardiac intervention was safely carried out during pregnancy in 10 women (PTMC in 7, CMV in l, and VR in 2). One of them developed congestive cardiac failure during labor. None of the newborns of the 41 women who had received anticoagulants had any congenital malformation.

CONCLUSIONS

Rheumatic heart disease was the predominant type. Patients in NYHA class I/II had a better maternal and fetal outcome than those in NYHA class III/IV. Surgical correction of the cardiac lesion prior to pregnancy was associated with better pregnancy outcome. Pregnant women with prosthetic valves tolerated pregnancy well.

Retina-derived microglial cells induce photoreceptor cell death in vitro

In animals with retinal degeneration, the presence of activated microglial cells in the outer retina during the early stages of injury suggests that they may be involved in the ensuing photoreceptor cell death. In the following study, we investigated the effects of rat retina-derived microglial cells on a photoreceptor cell line (661w) using cell culture techniques. The difficulty of obtaining pure populations of photoreceptor cells necessitated our use of the 661w photoreceptor cells generated from retinas of transgenic mice. 661w Cells were incubated for 24-48 h in basal medium or basal medium conditioned by activated microglial cells (MGCM) or Müller cells (MCCM), and tested for cell death using lactate dehydrogenase (LDH) assay. The induction of apoptosis in the 661w cells by MGCM was investigated using Terminal deoxynucleotidyl Transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) and DNA laddering. Treatment of 661w cells with MGCM for 48 h resulted in approximately 73% of cells dead as compared with 19-20% of cells grown in either basal medium or MCCM. Serum supplementation or pretreatment with heat did not abolish the cytotoxicity of MGCM. More TUNEL-positive cells were observed in MGCM-treated cultures as compared with those in basal medium. Bands in multiples of approximately 180 bp formed DNA ladders in MGCM-treated but not in basal medium-treated samples. Our study shows that microglial cells release soluble product(s) that induce degeneration of cultured photoreceptor cells. Moreover, the mechanism of microglia-induced photoreceptor cell death may involve apoptosis similar to that observed in animals with retinal degeneration.