Feasibility of a Composite Measure of Pulmonary Vascular Impedance and Application to Patients with Chronic RV Failure Post LVAD Implant

Pulmonary vascular impedance (PVZ) describes RV afterload in the frequency domain and has not been studied extensively in LVAD patients. We sought to determine (1) feasibility of calculating a composite (c)PVZ using standard of care (SoC), asynchronous, pulmonary artery pressure (PAP) and flow (PAQ) waveforms; and (2) if chronic right ventricular failure (RVF) post-LVAD implant was associated with changes in perioperative cPVZ.PAP and PAQ were obtained via SoC procedures at three landmarks: T(1), Retrospectively, pre-operative with patient conscious; and T(2) and T(3), prospectively with patient anesthetized, and either pre-sternotomy or chest open with LVAD, respectively. Additional PAP's were taken at T(4), following chest closure; and T(5), 4-24 h post chest closure. Harmonics (z) were calculated by Fast Fourier Transform (FFT) with cPVZ(z) = FFT(PAP)/FFT(PAQ). Total pulmonary resistance Z(0); characteristic impedance Zc, mean of cPVZ(2-4); and vascular stiffness PVS, sum of cPVZ(1,2), were compared at T(1,2,3) between +/-RVF groups.Out of 51 patients, nine experienced RVF. Standard hemodynamics and changes in cPVZ-derived parameters were not significant between groups at any T.In conclusion, cPVZ calculated from SoC measures is possible. Although data that could be obtained were limited it suggests no difference in RV afterload for RVF patients post-implant. If confirmed in larger studies, focus should be placed on cardiac function in these subjects.

Unusual presentation of intussusception: Gallstone ileus

Gallstone ileus is a rare pathology, occurring in an estimated 0.5% of cases, which preferentially affect females and the elderly population. This rare pathology is the result of a fistulous connection between the bowel and gallbladder. This connection allows gallstones to pass into the bowel leading to mechanical obstruction. On rare occasions the enteric gallstone can act as a lead point causing intussusception. We present a rare case of intussusception secondary to gallstone ileus in a young, relatively asymptomatic patient. CT played a critical role in diagnosis and appropriate management of our patient.

Late presentation of chronic hepatitis B virus in Spain: a country with access to therapy

Background and aims

Chronic infection with hepatitis B virus (HBV) can progress to liver cirrhosis and lead to complications such as decompensated liver disease, hepatocellular carcinoma and liver-related death. Antiviral agents against HBV are very effective in suppressing viremia and greatly reduce the risk of complications if treatment is initiated before the onset of advanced liver disease. The aim of this study is to assess the prevalence of late presentation in leading hospitals across Spain.

Methods

Retrospective cohort study of patients seeking first time care with a liver specialist at six tertiary Spanish hospitals, with 2018 data. Late presentation (LP) included advanced liver disease (ALD) defined by significant fibrosis (≥ F3 assessed by either APRI score > 1.5, FIB-4 > 3.2, transient elastography (FibroScan) > 9.5 kPa or biopsy ≥ METAVIR stage F3) with no previous antiviral treatment and late-stage liver disease (LSLD) was defined by the presence of decompensated cirrhosis and/or hepatocellular carcinoma. Prevalence of ALD and LSLD at first consultation, demographics, and associated risk factors were analysed.

Results

203 patients chronically infected with HBV were included. Advanced liver disease was detected in 14.8% and late stage liver disease was observed in 6.1% of cases. 57.1% of the cases were male. The majority of those with HBV were non-Spanish (53.7%). The median age was 47 and the median of years from diagnosis to specialist care was 1 (IQR 7). 58.6% of patients were referred from primary care and 3.7% cases had hepatocellular carcinoma upon presentation for care.

Conclusions

Late presentation with HBV is common in Spain, particularly for the foreign-born population, despite full access to antiviral therapy for HBV in the country. In order to rectify this health systems failure, improve outcomes and reach the viral hepatitis elimination goal adopted by WHO in 2016, strategies to reduce late presentation to care are essential.

Key messages

Early diagnosis of HBV is needed in order to rectify the health systems failure of late presentation to care. Interventions targeting foreign-born populations should be implemented to reduce late presentation to HBV care and treatment.

Trichomonad Gastritis in Rhesus Macaques (Macaca mulatta) Infected with Simian Immunodeficiency Virus

In a retrospective study, 51 cases of gastritis (14%) were identified from among 341 necropsies performed on simian immunodeficiency virus (SlV)-infected rhesus macaques ( Macaca mulatta) at the New England Primate Research Center from 1993 to 2001. Protozoa were seen in the stomach of 13 monkeys (25%) with gastritis. Two histopathologic manifestations of gastritis were observed: seven cases of lymphoplasmacytic gastritis with trichomonad trophozoites within lumens of gastric glands and four cases of necrosuppurative gastritis containing intralesional periodic acid-Schiff-positive protozoa; two cases of gastritis had morphologic features of both types of gastritis. In instances of necrosuppurative and combined lymphoplasmacytic and necrosuppurative gastritis, protozoa were 4-35 μm in diameter and round to tear-shaped. Because of the unusual morphology of the protozoa in these latter cases, transmission electron microscopy and polymerase chain reaction (PCR) were used to further identify these organisms. The protozoa were definitively identified as Tritrichomonas in all cases on the basis of ultrastructural characteristics (flagella and undulating membranes) and amplification of a 347-bp product of the 5.8S ribosomal RNA gene of Tritrichomonas foetus, Tritrichomonas suis and Tritrichomonas mobilensis by PCR using DNA extracted from stomach tissue. On the basis of these observations, we conclude that Tritrichomonas can be a significant cofactor in the development of necrosup-purative gastritis in SIV-infected rhesus macaques.

Factors promoting diabetes self-care among low-income, minority pregnant women

OBJECTIVE

To prospectively identify factors promoting healthy self-management of gestational and type 2 diabetes mellitus among underserved pregnant women.

STUDY DESIGN

Twenty-nine in-depth, semi-structured interviews were performed over the course of pregnancy for 10 women with diabetes. Interviews on factors promoting diabetes self-management used cognitive load theory to frame questions. Qualitative analysis of longitudinal interview data applied grounded theory techniques to generate themes.

RESULT

Half this cohort of minority, low-income, public aid-supported women had type 2 diabetes. Four themes, comprised of both internal self-driven motivators and external sources of support, were identified. These themes were: (1) disease familiarity and diabetes self-efficacy; (2) external motivation (for health of fetus and responsibilities to older children); (3) supportive social and physical environment; and (4) self-regulatory behavior, including goal responsiveness and long-term goal-setting.

CONCLUSION

Low-income women used multiple internal and external resources to promote health during a pregnancy complicated by diabetes. Successful behavior modification and achievement of diabetes care goals require leveraging these resources.

Abstract P5-12-01: A comparison of hormone receptor status in black women born in the U.S., West Africa, East Africa and the Caribbean - A SEER analysis

Background: Breast cancer is the leading cancer diagnosed among women in the United States (U.S.) and is second only to lung for cancer-related deaths in women. Although white women have a higher incidence of breast cancer, African American (AA) women with breast cancer have higher breast cancer related mortality and have a lower five year survival (73.8%) compared to their white counterparts (81.6%). AA women are also diagnosed at a younger age, with 30-40% of AA women diagnosed under 50, compared to 20% of whites, and are more likely to present with more estrogen receptor negative/progesterone receptor negative (ER-/PR-) tumors than whites (42% vs. 29% respectively). Other studies suggest these disparities extend to black African women and white European women. The aim of this study is to determine whether breast cancer characteristics seen in U.S. born black women are comparable to African born black women and to provide additional insight on the role of race and genetic ancestry in breast cancer.

Methods: Surveillance, Epidemiology, and End Results (SEER) data (SEER 18 Registries) was used to examine hormone receptor (HR) status among 30,003 black women, born in the U.S. (28,838), West Africa (167), East Africa (183), or the Caribbean (815), diagnosed with a first primary breast cancer from 2000 through 2009. Chi-square tests were used to determine whether clinical variables differed by ethnic group. Proportional incidence ratios (PIR) and 95% confidences intervals (CI) were calculated to estimate excess risk of ER-/PR- tumors between the populations.

Results: There were no statistically significant differences in axillary lymph node, stage, histologic type, or surgical treatment at presentation by ethnic group. There was no statistically significant difference in the proportion of ER-/PR- receptor status comparing US blacks to black women born in West Africa (p-value = 0.16, PIR = 0.77, 95% CI: 0.56-1.05), however women from East Africa and the Caribbean were less likely to have ER-/PR- breast cancers compared with US born blacks. (PIR = 0.52, 95% CI: 0.35-0.74, p < 0.0001 PIR = 0.84, 95% CI: 0.73-0.97, p< 0.01 respectively). The crude overall 5-year survival rate of West African, East African and Caribbean born black women was significantly higher than those born in the U.S. (75.7%, p = 0.023, 85.9% p <0.0001, 84.0% p<0.0001, 65.3% respectively).

Discussion: Our results agree with historical data showing that many AA women have ancestral origins in West Africa and provides additional evidence supporting the role of ancestral genetics in breast cancer susceptability.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-12-01.

A Novel Acquisition Technique to Utilize Swan-Ganz Catheter data as a Surrogate for High-fidelity Micromanometry within the Right Ventricle and Pulmonary Circuit

We explored the possibility of using conventional right-heart catheterization data, gathered both prospectively and retrospectively, as a surrogate for high-fidelity micro-manometery when analyzing systolic and diastolic RV function and calculating various ventricular and pulmonary hemodynamic parameters in the time domain. Right heart catheterizations were performed on 13 patients (7 female), who were suspected of having pulmonary hypertension. The procedure included use of both fluid-filled catheter and high-fidelity micromanometry to measure right ventricular and pulmonary arterial pressures. A digital data acquisition system was used to record micromanometer readings and data from the fluid-filled catheter system during prospective portion of the study. Retrospective data was obtained by direct digitization of screen captures taken by the conventional clinical system (fluid-filled catheter). From the 13 patients, 12-13 RV waveforms and 12 PA waveforms were acquired from each method. Basic measurements of heart rate, systolic pressure, diastolic pressure, dP/dt_max, and dP/dt_min were compared between micromanometry, direct acquisition from the PA catheter (voltage acquisition), and re-digitization of the hemodynamic waveforms (tracing). Correlation between Swan and tracing was stronger than that of Millar and Swan. SBP, followed by HR, has the strongest correlation of any parameter for all three methods, while DBP appears to be the weakest. Bland-Altman analysis shows all parameters to have minimal biases that are within clinical limits. Interoperator and intraoperator variability was minimal. Digital right-heart catheterization (RHC) data can be used as a surrogate for micromanometric data under ideal conditions for hemodynamic measures in the time domain. Pre-existing RHC data can be re-digitized for more rigorous hemodynamic analysis.

Pneumocystis carinii causes a distinctive interstitial pneumonia in immunocompetent laboratory rats that had been attributed to "rat respiratory virus"

A prevalent and distinctive infectious interstitial pneumonia (IIP) of immunocompetent laboratory rats was suspected to be caused by a putative virus, termed rat respiratory virus, but this was never substantiated. To study this disease, 2 isolators were independently populated with rats from colonies with endemic disease, which was perpetuated by the regular addition of naive rats. After Pneumocystis was demonstrated by histopathology and polymerase chain reaction (PCR) in the lungs of rats from both isolators and an earlier bedding transmission study, the relationship between Pneumocystis and IIP was explored further by analyzing specimens from 3 contact transmission experiments, diagnostic submissions, and barrier room breeding colonies, including 1 with and 49 without IIP. Quantitative (q) PCR and immunofluorescence assay only detected Pneumocystis infection and serum antibodies in rats from experiments or colonies in which IIP was diagnosed by histopathology. In immunocompetent hosts, the Pneumocystis concentration in lungs corresponded to the severity and prevalence of IIP; seroconversion occurred when IIP developed and was followed by the concurrent clearance of Pneumocystis from lungs and resolution of disease. Experimentally infected immunodeficient RNU rats, by contrast, did not seroconvert to Pneumocystis or recover from infection. qPCR found Pneumocystis at significantly higher concentrations and much more often in lungs than in bronchial and nasal washes and failed to detect Pneumocystis in oral swabs. The sequences of a mitochondrial ribosomal large-subunit gene region for Pneumocystis from 11 distinct IIP sources were all identical to that of P. carinii. These data provide substantial evidence that P. carinii causes IIP in immunocompetent rats.

Elder abuse and mortality: the role of psychological and social wellbeing

BACKGROUND

Elder abuse is a pervasive human right and public health issue.

OBJECTIVES

We aimed to examine the mortality associated with elder abuse across levels of psychological and social factors.

METHODS

The Chicago Health and Aging Project (CHAP) is a prospective population-based cohort study that began in 1993. A subset of these participants enrolled between 1993 and 2005 had elder abuse reported to social services agencies (n = 113). Mortality was ascertained during follow-up and with the National Death Index. Psychosocial factors (depression, social network and social engagement) were assessed during the CHAP interview. Cox proportional hazard models were used to assess the mortality of elder abuse across levels of psychosocial factors using time-varying covariate analyses.

RESULTS

The median follow-up time for the cohort (n = 7,841) was 7.6 years (interquartile range 3.8-12.4 years). In multivariate analyses, those with highest (hazard ratio (HR) 2.60, 95% CI 1.58-4.28) and middle levels (HR 2.18, 95% CI 1.19-3.99) of depressive symptoms had an increased mortality risk associated with elder abuse. For social network, those with lowest (HR 2.50, 95% CI 1.62-3.87) and middle levels (HR 2.65, 95% CI 1.52-4.60) of social network had increased mortality risk associated with elder abuse. For social engagement, those with lowest (HR 2.32, 95% CI 1.47-3.68) and middle levels (HR 2.59, 95% CI 1.65-5.45) of social engagement had increased mortality risk associated with elder abuse. Among those with lowest levels of depressive symptoms, highest levels of social network and social engagement, there was no significant effect of reported or confirmed elder abuse on mortality risk.

CONCLUSION

Mortality risk associated with elder abuse was most prominent among those with higher levels of depressive symptoms and lower levels of social network and social engagement.

STUDIES ON EXPERIMENTAL HYPERTENSION : XI. THE EFFECT OF EXCISION OF THE CAROTID SINUSES ON EXPERIMENTAL HYPERTENSION PRODUCED BY RENAL ISCHEMIA

Excision of both carotid sinuses, with or without section of cardio-aortic inhibitor fibers, was not followed by a significant change of femoral mean blood pressure from the normal. This procedure did not interfere with the development of hypertension produced by renal ischemia. There was no significant difference between the levels of hypertension due to renal ischemia in animals with both carotid sinuses previously excised and in those with both carotid sinuses intact. In one of three animals with hypertension due to renal ischemia, in which the elevated blood pressure had gradually subsided, there was a slight and only temporary reelevation of pressure after excision of both carotid sinuses. In the other two animals, excision of the carotid sinuses had no effect on the blood pressure. In all three, however, increased constriction of the renal arteries caused significant and persistent reelevation of the blood pressure. The carotid sinus has no demonstrable influence upon hypertension caused by renal ischemia, although in such animals it probably plays the same part in the regulation of blood pressure as it does in normal animals (7).

Variation in ecosystem function in Appalachian streams along an acidity gradient

Acidification is a widespread phenomenon that damages aquatic systems, and it has been the focus of intensive management efforts. While most management has focused on community structure as an endpoint, ecosystem function is also sensitive to acidification and important in stream health. We examined how a key ecosystem function in streams, leaf breakdown, varied along a gradient of pH resulting from acid deposition, natural conditions, and liming. We also measured how invertebrate and microbial assemblage structure and microbial function were related to altered leaf breakdown rates. Leaf breakdown rates declined more than threefold along a gradient of stream acidity from pH 6.8 to 4.9. The diversity of leaf-shredding invertebrates, bacteria, and fungi showed little response to variation in pH. The abundance of one acid-sensitive caddisfly, Lepidostoma, declined with acidification, and Lepidostoma abundance explained 37% of the variation in leaf breakdown rates among sites. Microbial respiration was suppressed along the acidity gradient, although the pattern was weaker than that for breakdown rate. In short-term laboratory incubations, microbes at acidic and circumneutral sites demonstrated adaptation to ambient pH. The activity of microbial extracellular enzymes was strongly influenced by pH. In particular, the pattern of activity of phosphatase indicated increasing P limitation of microbes with increasing acidification. Our results show that leaf breakdown is a sensitive tool for examining the response of stream function to acidification and also for defining the mechanisms that drive functional response. Future management efforts should focus on key taxa that are particularly sensitive and effective at shredding leaves and also the role of shifting acidity in mediating the availability of phosphorus to microbial films that are important for stream function.

Comparison of the effects and disposition kinetics of lidocaine and (+/-)prilocaine in patients undergoing axillary brachial plexus block during day case surgery

OBJECTIVE

The aim of this investigation was to compare the clinical effects and pharmacokinetics of lidocaine and prilocaine in two groups of 15 patients undergoing axillary brachial plexus anaesthesia.

METHODS

The study had a randomised design. Patients were allocated to one of the two groups of 15. Each group received either lidocaine (600mg = 2.56 mmol/L + 5 mg/L adrenaline) or prilocaine (600mg = 2.72 mmol/L + 5 mg/L adrenaline), injected over a period of 30 seconds. Onset of the surgical analgesia was defined as the period from the end of the injection of the local anaesthetic to the loss of pinprick sensation in the distribution of all three nerves.

RESULTS

The mean onset time of surgical analgesia of both lidocaine and prilocaine was 10 minutes. Lidocaine was biexponentially eliminated with a rapid elimination phase half-life (t((1/2)alpha)) of 9.95 +/- 14.3 minutes and a terminal elimination phase half-life (t((1/2)beta)) of 2.86 +/- 1.55 hours. Lidocaine was metabolised to MEGX (monoethylglycylxylidide); time to reach maximum plasma concentration (tmax) 2.3 +/- 0.8 hours; maximum plasma concentration (C(max)) 0.32 +/- 0.13 mg/L; t((1/2)beta) 2.4 +/- 2.4 hours. Lidocaine total body clearance was 67.8 +/- 28.8 L/h. Prilocaine was rapidly and biexponentially eliminated with a t((1/2)alpha) of 9.4 +/- 18.4 minutes and a t((1/2)beta) of 2.12 +/- 1.28 hours. The total body clearance of prilocaine (150 +/- 53 L/h) was higher than that of lidocaine (p = 0.0255). Both compounds demonstrated a comparable volume of distribution (Vd), while the volume of distribution at steady-state (V(ss)) and the volume of distribution in the second compartment (V(beta)) values of prilocaine were a factor of 1.6 higher than those of lidocaine (p < 0.001). Both compounds showed a comparable t((1/2)alpha) (p > 0.8) and a comparable t((1/2)beta) (p = 0.26).

CONCLUSION

Following axillary administration, lidocaine and prilocaine demonstrated similar pharmacokinetic behaviour and could therefore be used as the clinical preference for this regional anaesthesia technique.

Fecal microbiota in sensitized wheezy and non-sensitized non-wheezy children: a nested case-control study

BACKGROUND

It has been suggested that intestinal microbiota of allergic and non-allergic children differs in composition, and that microbiota-immune system interactions may predispose children to develop sensitization. Previous studies have examined fecal microbiota of allergic children with atopic dermatitis, but little is known about that of atopic wheezy children.

OBJECTIVE

To investigate the composition of the fecal microbiota of young sensitized wheezy and non-sensitized non-wheezy children, using molecular methods.

METHODS

Within the context of a prospective birth cohort, we carried out a nested case-control study of sensitized wheezy children (cases) and non-sensitized non-wheezy controls. Cases and controls were matched for age, sex, parental atopy, allergen exposure, and pet ownership. We evaluated the composition of fecal microbiota by nucleic acid-based methods (PCR combined with denaturing gradient gel electrophoresis and quantification of bifidobacteria by fluorescent in situ hybridization).

RESULTS

Thirty-three case-control pairs (mean age 4.4 years) provided stool samples. Comparison of total bacterial community profiles showed that each child had a unique fecal microbiota (mean Dice's similarity coefficient 22%, range 3.3-60.8%). There was no difference between the groups in prevalence of Lactic Acid bacteria (12/33 vs. 11/33, P=0.8) or bifidobacteria (30/33 vs. 31/33, P=1.00, cases vs. controls). The bifidobacterial species detected were similar in both groups. The percentage of bifidobacteria in total fecal microflora was no different between cases (median 1.7%, range 0-20.8%) and controls (1.9%, 0-18.2%, P=0.7). However, cases with eczema had significantly fewer bifidobacteria (median 1.6%, range 0-4.8%) than their controls (4.0%, 1.9-18.2%, P=0.05).

CONCLUSION

We found no differences in fecal microbiota composition between sensitized wheezy and non-sensitized, non-wheezy children aged 3-5 years using nucleic acid-based methods. Differences appear to be isolated to those allergic children with eczema.

Analysis of the large bowel microbiota of colitic mice using PCR/DGGE

AIM

To test combined polymerase chain reaction amplification of 16S rRNA gene sequences and denaturing gradient gel electrophoresis (PCR/DGGE) as an analytical method to investigate the composition of the large bowel microbiota of mice during the development of colitis.

METHODS AND RESULTS

The colonic microbiota of formerly germfree interleukin 10 (IL-10)-deficient mice that had been exposed to the faecal microbiota of specific pathogen-free animals was screened using PCR/DGGE. The composition of the large bowel microbiota of IL-10-deficient mice changed as colitis progressed. DNA fragments originating from four bacterial populations ('Bacteroides sp.', Bifidobacterium animalis, Clostridium cocleatum, enterococci) were more apparent in PCR/DGGE profiles of colitic mice relative to non-colitic animals, whereas two populations were less apparent (Eubacterium ventriosum, Acidophilus group lactobacilli). Specific DNA:RNA dot blot analysis showed that bifidobacterial ribosomal RNA (rRNA) abundance increased as colitis developed.

CONCLUSIONS

PCR/DGGE was shown to be an effective method to demonstrate changes in the composition of the large bowel microbiota of mice in relation to progression of inflammatory disease. The intensity of staining of DNA fragments in DGGE profiles reflected increased abundance of bifidobacterial rRNA in the microbiota of colitic animals. As bifidobacterial fragments in PCR/DGGE profiles generated from microbiota DNA showed increased intensity of fragment staining, an increase in bifidobacterial numbers in colitic mice was indicated.

SIGNIFICANCE AND IMPACT OF THE STUDY

PCR/DGGE analysis demonstrated an altered composition of the large bowel microbiota of colitic mice. This work will allow specific groups of bacteria to be targeted in future research concerning the pathogenesis of colitis.

Impact of consumption of oligosaccharide-containing biscuits on the fecal microbiota of humans

Human subjects consumed biscuits containing either galacto-oligosaccharides or fructo-oligosaccharides in a double-blinded, crossover study. The impact of supplementing the diet with three biscuits per day on the fecal microbiota was evaluated by selective culture of particular bacterial groups, measurement of beta-galactosidase activity, and nucleic acid-based analytical methods (PCR-denaturing gradient gel electrophoresis [PCR-DGGE] and fluorescent in situ hybridization). The composition of the bifidobacterial populations was monitored at the level of species (PCR-DGGE) and strains (pulsed-field gel electrophoresis of DNA digests), and representative cultures were tested quantitatively for their ability to use galacto-oligosaccharides. Technical improvements to DGGE analysis of the microbiota were made by the use of an internal standard that allowed valid comparisons of fragment staining intensities to be made between profiles, the use of S1 nuclease digestion to remove single-stranded DNA to facilitate cloning of DNA sequences cut from gels, and the extraction of RNA to be used as the template in reverse transcription-PCR-DGGE. RNA-DGGE profiles were markedly different (Dice's similarity coefficient, 58.5%) from those generated by DNA-DGGE. Neither the sizes of the bacterial populations nor the DNA-DGGE profiles of the microbiota were altered by the consumption of the biscuits, but the RNA-DGGE profiles were altered by the detection or increased staining intensity of 16S rRNA gene sequences originating from Bifidobacterium adolescentis and/or Colinsella aerofaciens in the feces of 11 of 15 subjects. beta-Galactosidase activity was elevated in the feces of some subjects as a result of biscuit consumption. Subjects differed in the ability of the bifidobacterial strains harbored in their feces to use galacto-oligosaccharides. Our observations suggest that a phylogenetic approach to analysis of the gut ecosystem may not always be optimal and that a more physiological (biochemical) method might be more informative.

Bifidobacterial species differentially affect expression of cell surface markers and cytokines of dendritic cells harvested from cord blood

The gut microbiota may be important in the postnatal development of the immune system and hence may influence the prevalence of atopic diseases. Bifidobacteria are the most numerous bacteria in the guts of infants, and the presence or absence of certain species could be important in determining the geographic incidence of atopic diseases. We compared the fecal populations of bifidobacteria from children aged 25 to 35 days in Ghana (which has a low prevalence of atopy), New Zealand, and the United Kingdom (high-prevalence countries). Natal origin influenced the detection of bifidobacterial species in that fecal samples from Ghana almost all contained Bifidobacterium infantis whereas those of the other children did not. Choosing species on the basis of our bacteriological results, we tested bifidobacterial preparations for their effects on cell surface markers and cytokine production by dendritic cells harvested from cord blood. Species-specific effects on the expression of the dendritic-cell activation marker CD83 and the production of interleukin-10 (IL-10) were observed. Whereas CD83 expression was increased and IL-10 production was induced by Bifidobacterium bifidum, Bifidobacterium longum, and Bifidobacterium pseudocatenulatum, B. infantis failed to produce these effects. We concluded that B. infantis does not trigger the activation of dendritic cells to the degree necessary to initiate an immune response but that B. bifidum, B. longum, and B. pseudocatenulatum induce a Th2-driven immune response. A hypothesis is presented to link our observations to the prevalence of atopic diseases in different countries.

Immunoglobulin-A nephropathy with crescentic glomerulonephritis in a pigtailed macaque (Macaca nemestrina)

A 4-year-old female pigtailed macaque (Macaca nemestrina), experimentally coinfected with simian immunodeficiency virus (SIVmac251) and Mycobacterium bovis(bacillus Calmette-Guerin), was euthanatized 1 year after infection because of weight loss and labored breathing. On gross examination, both kidneys were found to be markedly enlarged (right: 54.7 g and left: 51.7 g; normal < 20 g). Renal lesions were evaluated by histopathologic, immunohistochemical, and ultrastructural methods. Light microscopy revealed that the glomeruli were diffusely hypercellular with expansion of the mesangial matrix, and crescent formation affected approximately 60% of the glomeruli. By immunohistochemical evaluation, it was found that the crescents were composed principally of macrophages, as seen by CD68 (KP1), MRP8, MAC387, and HAM56 expression. Electron microscopic examination of the glomeruli revealed extensive intramembranous, subendothelial, and mesangial electron-dense deposits and multifocal fusion of the visceral epithelial foot processes. Immunofluorescence, used to determine the composition of the electron-dense deposits, revealed diffuse granular mesangial and capillary staining for immunoglobulin A (IgA). The renal changes described in this case report are most consistent with the findings of crescentic gloerulonephritis with IgA immune complex deposition in the glomerular basement membrane and mesangium as described in humans with IgA nephropathy.

Comparison of the faecal microflora of patients with ankylosing spondylitis and controls using molecular methods of analysis

OBJECTIVES

To determine whether differences within the complex intestinal microflora can be demonstrated between patients with ankylosing spondylitis (AS) and healthy individuals.

METHODS

The composition of the faecal microflora of 15 ankylosing spondylitis patients and 15 matched controls was determined using a variety of nucleic acid-based methods, including denaturing gradient gel electrophoresis (DGGE). Concentrations of serum antibodies reactive with intestinal bacteria were determined. T-cell proliferation responses to autologous intestinal bacteria were determined using a bioluminescent assay.

RESULTS

DGGE demonstrated a unique and stable bacterial community in the faeces of each individual. No specific differences in colonization profiles were discernible between patients and controls. Analysis of individual bacterial groups using nucleic acid-based methods showed no differences in faecal colonization with Klebsiella pneumoniae or Bacteroides vulgatus. A significantly higher proportion of faecal samples from AS patients were found to contain sulphate-reducing bacteria compared with samples from controls (P=0.0004). Three out of five patients showed elevated T-cell proliferation responses to Bacteroides species cultured from their own faeces. The concentrations of serum immunoglobulin A (IgA) and IgM antibodies reactive with klebsiella or bacteroides cells were lower in the patient group relative to the controls.

CONCLUSIONS

By using DGGE, we have demonstrated the complexity and individuality of the human intestinal microflora and shown that this is a confounding factor in determining the possible significance of individual organisms in the pathogenesis of spondyloarthritis. Nevertheless, we demonstrated a higher prevalence of sulphate-reducing bacteria in the faeces of patients with AS. These organisms have been implicated in the pathogenesis of inflammatory bowel disease. We also detected a possible loss of immunological tolerance to autologous Bacteroides isolates in patients with AS.

Expression of peripherin in the brain of macaques (Macaca mulatta and Macaca fascicularis) occurs in astrocytes rather than neurones and is associated with encephalitis

Peripherin is a member of the type III intermediate filament family, expressed in neurones of the peripheral nervous system of many species and in a discrete subpopulation of neurones of the central nervous system (CNS) during early development in rodents. Previous studies on rats have shown that peripherin immunoreactivity increased significantly in cell bodies of spinal motor neurones following axonal injury. Our study examined the expression of peripherin in the cerebrum of normal macaques (Macaca mulatta and Macaca fascicularis) and those with encephalitis of viral (simian immunodeficiency virus and simian virus 40) or autoimmune (experimental allergic encephalomyelitis) aetiology. Immunohistochemistry, immunoelectronmicroscopy, immunofluorescence and confocal microscopy were performed on tissue sections using antibodies against cell-specific markers and peripherin. Peripherin-positive cells were absent in the cerebrum of normal macaques of all ages examined, whereas animals with encephalitis had peripherin-positive cells associated with inflammatory infiltrates. Further evaluation revealed that these peripherin-positive cells were not neurones, but were predominantly astrocytes expressing glial fibrillary acidic protein. Our study suggests that peripherin is not neurone-specific in the CNS of macaques; peripherin is expressed in astrocytes of animals with encephalitis.

The epidemiology of organophosphate poisoning in urban Zimbabwe from 1995 to 2000

The objective of this study was to examine current organophosphate usage in Zimbabwe. A cross-sectional descriptive study was done to determine the trends in admissions for organophosphate poisonings in an urban Zimbabwe hospital from 1995 to 2000. Variables such as sex, age, season, geographic area, and intent were examined. In 183,569 records, 599 cases of organophosphate poisoning were found. Organophosphate poisonings increased by 320% over the six years. The male and female admissions' rates were similar (48% vs 52%); 82% of the patients were less than 31 years old. Suicide was the predominant reason for poisoning (74%). Of admissions of children under the age of 10, 62% were due to accidental ingestion. Mortality from organophosphate poisonings was 8.3% over the six years. Organophosphate poisoning is increasing rapidly. In the background of this alarming trend is the physical, mental, and social state of a Zimbabwean society wrought with hardships.

Local progression after operative treatment of metastatic kidney cancer

The cases of 78 patients with osseous metastases from kidney cancer were reviewed to determine the rate of local progression after operative resection as compared with more traditional intralesional procedures. Group I consisted of 41 (53%) patients who were treated with intralesional procedures involving internal fixation with or without curettage or polymethylmethacrylate. Of the 41 patients, additional operations were recommended for 17 (41%) of the patients who had local osseous progression. Fourteen additional procedures including nine wide resections with reconstruction, three amputations, and two mass excisions were done. Group II consisted of 37 (47%) patients who were treated with marginal or wide resection with or without reconstruction. In this group, only one patient required additional operative intervention for local osseous progression. Median survival of patients in Group I was 20 months compared with 35 months for patients in Group IL This study shows that despite shorter average survival, patients who undergo intralesional surgery are at high risk of reoperation for local progression. Resectional surgery should be considered in patients with skeletal metastases from kidney cancer to lessen the risk of reoperation for local progression.

Giant bilateral renal angiomyolipomas associated with tuberous sclerosis

Renal angiomyolipomas in patients with tuberous sclerosis can be associated with significant morbidity, mostly related to complications from bleeding. We describe a patient with tuberous sclerosis and massive bilateral renal angiomyolipomas (total tumor burden 5500 g) who presented with acute right renal hemorrhage. She was treated with right renal artery embolization followed immediately by right nephrectomy and left partial nephrectomy. The patient had a creatinine nadir of 1.3 mg/dL postoperatively. We demonstrate that nephron-sparing surgery is feasible, even in the setting of very large angiomyolipomas, such as the one presented here, currently the largest such tumor by weight reported.

Initial review of Electronic Residency Application Service charts by orthopaedic residency faculty members. Does applicant gender matter?

BACKGROUND

Orthopaedic surgery is a male-dominated field. As of 1998, women accounted for 42% of medical school graduates, yet only 6.9% of the total number of orthopaedic residents were female. The purpose of our study was to determine whether the Electronic Residency Application Service charts of female candidates for orthopaedic residencies are ranked lower by faculty reviewers than are those of male candidates with similar qualifications.

METHODS

After we obtained permission from the applicants, the Electronic Residency Application Service applications submitted by ninety male and ten female candidates for admission to a university orthopaedic residency program for the 1998 National Residency Matching Program were randomly divided into ten groups, consisting of the charts of nine male candidates and one female candidate. Each chart from a female candidate was altered into a "male" version, in which all names and personal pronouns were changed but which was otherwise identical to the original female version. Therefore, each group of ten charts existed as a paired set: one containing the true female chart and one, the altered "male" chart. The paired sets acted as their own control. One hundred and twenty-one faculty reviewers from fourteen orthopaedic residency programs around the United States each reviewed either the "male" or the female version of one set, without knowledge of the goals of the study, and ranked the ten charts in the order in which they would like to have the candidates as residents in their own programs. Each version of the sets was reviewed by at least five separate reviewers. Reviewers at a given institution were randomized to review different sets, so that there was no overlap among them. The rankings of the female-"male" pairs were compared with use of a standard paired t test.

RESULTS

No significant difference was detected in the rankings of the female and "male" charts (p = 0.5). The mean difference in rankings was -0.33, with a 95% confidence interval ranging from -1.41 (favoring females) to 0.74 (favoring "males").

CONCLUSIONS

The low percentage of female residents is not due to bias against female applicants in the initial chart-review phase of the orthopaedic residency selection process. It is possible that bias is introduced in other stages of the selection process, such as the interview.

Pulmonary cryptosporidiosis in simian immunodeficiency virus-infected rhesus macaques

Cryptosporidiosis is a common opportunistic infection in the gastrointestinal tract of human and nonhuman primates with AIDS. Pulmonary infection associated with Cryptosporidium spp. has not been previously reported in monkeys. Two macaques experimentally infected with simian immunodeficiency virus (SIV) had lesions containing cryptosporidial organisms involving the trachea, lungs, bile ducts, pancreas, and intestine. The pulmonary sections revealed moderate to severe bronchopneumonia associated with cryptosporidiosis. Numerous 2-4 microm oval Cryptosporidium spp. organisms were present in the cytoplasm of alveolar macrophages, multinucleated giant cells, and intestinal epithelial cells. Giant cells were positive for SIV by in situ hybridization. These are the first reported cases of cryptosporidiosis with involvement of pulmonary parenchyma in SIV-infected macaques.

Inotropes in the beta-blocker era

Beta-adrenergic blocking agents are now standard treatment for mild to moderate chronic heart failure (CHF). However, although many subjects improve on beta blockade, others do not, and some may even deteriorate. Even when subjects improve on beta blockade, they may subsequently decompensate and need acute treatment with a positive inotropic agent. In the presence of full beta blockade, a beta agonist such as dobutamine may have to be administered at very high (> 10 micrograms/kg/min) doses to increase cardiac output, and these doses may increase afterload. In contrast, phosphodiesterase inhibitors (PDEIs) such as milrinone or enoximone retain their full hemodynamic effects in the face of beta blockade. This is because the site of PDEI action is beyond the beta-adrenergic receptor, and because beta blockade reverses receptor pathway desensitization changes, which are detrimental to PDEI response. Moreover, when the combination of a PDEI and a beta-blocking agent is administered long term in CHF, their respective efficacies are additive and their adverse effects subtractive. The PDEI is administered first to increase the tolerability of beta-blocker initiation by counteracting the myocardial depressant effect of adrenergic withdrawal. With this combination, the signature effects of beta blockade (a substantial decrease in heart rate and an increase in left ventricular ejection fraction) are observed, the hemodynamic support conferred by the PDEI appears to be sustained, and clinical results are promising. However, large-scale placebo-controlled studies with PDEIs and beta blockers are needed to confirm these results.

Dilated cardiomyopathy associated with simian AIDS in nonhuman primates

BACKGROUND

Cardiomyopathy is being recognized with increasing frequency in patients with AIDS, yet the relationship between HIV infection and cardiac contractile dysfunction remains obscure. The purpose of the present study was to determine if infection with simian immunodeficiency virus (SIV) in nonhuman primates is associated with cardiac dysfunction and myocardial injury.

METHODS AND RESULTS

Left ventricular size and function were determined by 2D echocardiography in 16 rhesus macaques before and at weekly intervals following infection with cloned pathogenic SIV(mac) 239 or the highly attenuated SIV(mac) 239 nef deletion mutant. A second group of 15 rhesus macaques chronically infected with pathogenic (n=6) or nonpathogenic (n=9) virus were studied at >2 years following infection. Cardiac tissues from 24 rhesus macaques chronically infected (>2 years) with pathogenic SIV were reviewed for evidence of cardiac pathology. Acute infection (<6 weeks) with either pathogenic or nonpathogenic SIV caused neither contractile dysfunction nor cardiac pathology. However, LV ejection fraction was significantly (P<0.05) depressed (43+/-7%) in rhesus macaques chronically infected with pathogenic SIV compared with rhesus macaques chronically infected with nonpathogenic SIV (61+/-3%). Furthermore, two thirds of rhesus macaques that succumbed to simian AIDS had myocardial pathology including lymphocytic myocarditis (n=9) and coronary arteriopathy (n=6), with complete vessel occlusion (n=4) and associated myocardial infarction and necrosis.

CONCLUSIONS

This unique model is valuable in understanding the pathogenesis of cardiac injury associated with retroviral infection in a relevant nonhuman primate model of AIDS.

Recruitment of the protein tyrosine phosphatase CSW by DOS is an essential step during signaling by the sevenless receptor tyrosine kinase

The pleckstrin homology (PH) domain-containing protein Daughter of Sevenless (DOS) is an essential component of the Sevenless receptor tyrosine kinase (SEV) signaling cascade, which specifies R7 photoreceptor development in the Drosophila eye. Previous results have suggested that DOS becomes tyrosine phosphorylated during SEV signaling and collaborates with the protein tyrosine phosphatase CSW. We have investigated this possibility by identifying tyrosine residues 801 and 854 of DOS as the phosphorylated binding sites for the CSW SH2 domains. We show that these sites become phosphorylated in response to SEV activation and that phosphorylation of both sites is required to allow CSW to bind DOS. Mutant DOS proteins in which either Y801 or Y854 of DOS has been changed to phenylalanine are unable to function during signaling by SEV and other receptor tyrosine kinases. In contrast, we find that a mutant DOS protein in which all tyrosine phosphorylation sites except Y801 and Y854 have been removed is able effectively to provide DOS function during SEV signaling and to rescue the lethality associated with dos loss-of-function mutations. These results indicate that a primary role for DOS during signaling by SEV and other receptor tyrosine kinases is to become phosphorylated at Y801 and Y854 and then recruit CSW.

mirror controls planar polarity and equator formation through repression of fringe expression and through control of cell affinities

The Drosophila eye is divided into dorsal and ventral mirror image fields that are separated by a sharp boundary known as the equator. We have previously demonstrated that Mirror, a homeodomain-containing putative transcription factor with a dorsal-specific expression pattern in the eye, induces the formation of the equator at the boundary between mirror-expressing and non-expressing cells. Here, we provide evidence that suggests mirror regulates equator formation by two mechanisms. First, mirror defines the location of the equator by creating a boundary of fringe expression at the mid-point of the eye. We show that mirror creates this boundary by repressing fringe expression in the dorsal half of the eye. Significantly, a boundary of mirror expression cannot induce the formation of an equator unless a boundary of fringe expression is formed simultaneously. Second, mirror acts to sharpen the equator by reducing the mixing of dorsal and ventral cells at the equator. In support of this model, we show that clones of cells lacking mirror function tend not to mix with surrounding mirror-expressing cells. The tendency of mirror-expressing and non-expressing cells to avoid mixing with each other is not determined by their differences in fringe expression. Thus mirror acts to regulate equator formation by both physically separating the dorsal cells from ventral cells, and restricting the formation of a fng expression boundary to the border where the dorsal and ventral cells meet.

Aneurysmal bone cyst of the extremities. Factors related to local recurrence after curettage with a high-speed burr

BACKGROUND

Aneurysmal bone cyst is a benign, locally destructive lesion of bone. The rates of local recurrence after curettage have varied widely. Therefore, we performed a retrospective study of patients who had had an aneurysmal bone cyst in order to identify the rate of local recurrence and the prognostic factors related to local recurrence after use of contemporary methods of curettage with a high-speed burr.

METHODS

We reviewed the cases of forty patients who had been managed by the same surgeon for an aneurysmal bone cyst, as diagnosed on the basis of the latest pathological review, between January 1, 1976, and December 31, 1993. The patients were evaluated with regard to age, gender, the duration and type of symptoms, the presence or absence of pathological fracture, the status of the growth plate, the bone and part of the bone that were involved, the type of operative procedure, the outcome, the radiographic stage, the findings on magnetic resonance imaging and computerized tomography (when it became available) and on bone scintigraphy, and histological parameters. The median duration of follow-up was eighty-seven months (range, fifteen to 267 months). According to the criteria of Enneking, no patient had a stage-1 lesion (one with a surrounding rim of cortical bone), twenty-four had a stage-2 lesion (one with a clearly defined border but no cortical bone), and sixteen had a stage-3 lesion (one with no clearly defined border).

RESULTS

Of the forty patients, thirty-four had curettage with use of a high-speed burr. Of these thirty-four, twenty-two had filling of the defect with a cancellous autogenous graft; four, with a cancellous allograft; and three, with polymethylmethacrylate. In five patients, no material was put into the defect. The remaining six patients had resection through the margin of the lesion. Four (12 percent) of the thirty-four patients who had curettage had a local recurrence. No patient who had an excision through the margin of the lesion had a local recurrence. All local recurrences were in skeletally immature girls who were three, four, ten, and eleven years old. Univariate analysis with use of the chi-square, Fisher exact, and Wilcoxon log-rank tests showed that local recurrence was associated only with a young age (p = 0.0036) and open growth plates (p = 0.039). All local recurrences occurred within two years postoperatively, at two, seven, nine, and twenty-four months, and all were treated successfully with a second operation.

CONCLUSIONS

Rates of local control of almost 90 percent can be achieved with thorough curettage with use of a mechanical burr and without use of liquid nitrogen, phenol, or other adjuvants in patients who have an aneurysmal bone cyst of an extremity. A young age and open growth plates are associated with an increased risk of local recurrence.

Similar motor block effects with different disposition kinetics between lidocaine and (+ or -) articaine in patients undergoing axillary brachial plexus block during day case surgery

AIM

The aim of this investigation was to compare the clinical effects and pharmacokinetics of lidocaine and articaine in two groups of 15 patients undergoing axillary brachial plexus anesthesia.

METHOD

The study had a randomized design. Thirty patients were allocated to one of the two groups. Each patient received either lidocaine (600 mg = 2.561 mMol + 5 microg/ml adrenaline) or articaine (600 mg = 2.113 mMol + 5 microg/ml adrenaline), injected via the axilla of the brachial plexus over a period of 30 seconds. Onset of surgical analgesia was defined as the period from the end of the injection of the local anesthetic to the loss of pinprick sensation in the distribution of all three nerves.

RESULTS

The mean onset time of sensory block of the median nerve of both lidocaine and articaine were approximately 10 min. Lidocaine is biexponentially eliminated with a t1/2alpha of 9.95 +/- 14.3 min and a t1/2beta of 2.86 +/- 1.55 h. Lidocaine is metabolized into MEGX (mono-ethyl-glycyl-xilidide) (t(max) 2.31 +/- 0.84 h; C(max) 0.32 +/- 0.13 mg/l; t1/2beta 2.36 +/- 2.35 h). Lidocaine total body clearance was 67.9 +/- 28.9 l/h. Articaine is rapidly and monoexponentially eliminated with a t1/2beta of 0.95 +/- 0.39 h. The total body clearance of articaine is higher than that of lidocaine, 1,133 +/- 582 l/h vs 67.9 +/- 28.9 l/h, respectively (p < 0.0001). The volume of distribution (V(d)), of articaine is a factor 16 higher times than that of lidocaine (p < 0.0001).

CONCLUSION

For the axillary administration, lidocaine and articaine show similar pharmacodynamics with a different pharmacokinetic behavior and can therefore be used to the clinical preference for this regional anesthetic technique.

Fatal measles virus infection in Japanese macaques (Macaca fuscata)

An outbreak of natural measles virus infection occurred in a group of Japanese macaques (Macaca fuscata). Over a period of 4 months, 12 of 53 Japanese macaques died following a 2-23-day history of anorexia, diarrhea, and dermatitis. The monkeys were kept in outdoor exhibits but had been moved temporarily into indoor caging and then transferred to new outdoor exhibits. Ten monkeys died while they were in temporary caging, and two monkeys died after they were moved to new outdoor exhibits. The diagnoses were made based on the results of histopathology, immunohistochemistry (IHC), in situ hybridization (ISH), and electron microscopy. Measles virus antigens were detected in the lung, stomach, skin, salivary gland, spleen, and lymph nodes. Tangled, tubular nucleocapsids compatible with paramyxovirus were noted in the lung tissue. As a result of immunosuppression following measles virus infection, various secondary infections including disseminated cytomegalovirus infection, adenoviral and bacterial pneumonia, and Candida albicans-associated gingivitis and esophagitis were noted. The primary infective source or the mode of infection could not be determined in this outbreak, but measles virus may have been transmitted to the monkeys from human visitors while the monkeys were on exhibit.

Botanical medicines with gynecological anticancer activity: a literature review

This article reviews the existing scientific literature reporting effects of botanical substances on the prevention and treatment of gynecological cancers. Anticancer effects were reported for 14 of 27 herbal substances searched for, 8 of which had reported effects specifically in gynecological cancer models. Research reviewed included in vitro studies in gynecological cancer cell lines, animal studies, an ex vivo study, and an epidemiological study. No clinical trials on gynecological cancer prevention or treatment were found for any of the 8 identified agents. Despite the increasing use of botanical medicines in the prevention and treatment of cancer in general, there is a paucity of studies describing their efficacy or safety in gynecological cancer. Given the prevalent use of botanical medicine in complementary and alternative cancer therapy, the need for research to evaluate safety and efficacy using both in vitro and in vivo methods is pressing.

Neuropathogenesis of simian immunodeficiency virus in neonatal rhesus macaques

Neonatal human immunodeficiency virus (HIV) infection usually occurs intrapartum or postpartum and results in a higher incidence of neurological dysfunction than is seen in adults. To explore the neuropathogenesis of neonatal HIV infection, we infected neonatal macaques with simian immunodeficiency virus (SIV) and followed the course of infection focusing on early time points. Infected neonates had decreased brain growth and mild histological changes in brain that resembled those seen in pediatric AIDS, including perivascular infiltrates of mononuclear cells, mineralization of vessels in the basal ganglia, and gliosis. The perivascular lesions and gliosis were associated with the presence of occasional infected cells that required in situ hybridization with radiolabeled riboprobes for detection. Using this technique, SIV-infected cells were detected in the brain parenchyma within 7 days of infection. These findings were confirmed by nested PCR for SIVgag DNA in brain and RT-PCR for viral RNA in cerebrospinal fluid. Together, these techniques revealed SIV infection of the CNS in 12 of 13 neonates infected with SIVmac239, 3 of 3 infected with SIVmac251, and 2 of 2 infected with SIVmac239/316. The prevalence of CNS infection was indistinguishable from that of older animals infected with the same dose and stock of virus, but neonates appeared to have fewer infected cells in the CNS and detecting them required more sensitive techniques. This observation was true regardless of inoculum and despite the fact that neonates had equal or greater viral loads in the periphery compared with older animals. These data suggest that maturation-dependent host factors have a major impact on the neuropathogenesis of pediatric AIDS.

Nodular Pneumocystis carinii pneumonia in SIV-infected macaques

Pneumocystis carinii (PC) pneumonia is a frequent manifestation of the acquired immunodeficiency syndrome (AIDS) in humans and macaques. An unusual nodular type of PC pneumonia was observed in two simian immunodeficiency virus (SIV)-inoculated rhesus macaques (Macaca mulatta). These animals developed clinical signs of simian AIDS, including anorexia, weight loss, dyspnea, and collapse. Grossly, both animals had multifocal tan-white nodules 1-10 mm in diameter scattered throughout the lungs. One animal had similar nodules involving the diaphragm and thoracic wall. The lungs were characterized by severe PC pneumonia with numerous large nodules consisting of foamy material that compressed adjacent tissue. The nodules had central areas of necrosis and lysis of alveolar septa. Varying degrees of necrotizing vasculitis were observed in areas of nodular PC pneumonia. The presence of PC in intra-alveolar spaces and nodular lesions was confirmed by immunohistochemistry. No evidence of other agents, including viral inclusions, bacteria, fungi, and lung mites, was detected. The animal with the most severe nodular PC pneumonia had vascular involvement with extrapulmonary spread to the diaphragm, thoracic wall, and regional lymph nodes. This unusual type of nodular PC pneumonia has been rarely seen in human AIDS patients.

A nonhuman primate model for the selective elimination of CD8+ lymphocytes using a mouse-human chimeric monoclonal antibody

Nonhuman primates provide valuable animal models for human diseases. However, studies assessing the role of cell-mediated immune responses have been difficult to perform in nonhuman primates. We have shown that CD8+ lymphocyte-mediated immunity in rhesus monkeys can be selectively eliminated using the mouse-human chimeric anti-CD8 monoclonal antibody cM-T807. In vitro, this antibody completely blocked antigen-specific expansion of cytotoxic T cells and decreased major histocompatibility complex class I-restricted, antigen-specific lysis of target cells but did not mediate complement-dependent cell lysis. In vivo administration of cM-T807 in rhesus monkeys resulted in near total depletion of CD8+ T cells from the blood and lymph nodes for up to 6 weeks. This depletion was not solely complement-dependent and persisted longer in adults than in juveniles. Preservation of B cell and CD4+ T cell function in monkeys depleted of CD8+ lymphocytes was demonstrated by their ability to develop humoral immune responses to the administered chimeric monoclonal antibody. Furthermore, during CD8+ lymphocyte depletion, monkeys developed delayed-type hypersensitivity reactions comprised only of CD4+ T cells but not CD8+ T cells. This CD8+ lymphocyte depletion model should prove useful in defining the role of cell-mediated immune responses in controlling infectious diseases in nonhuman primates.

Delay in the diagnosis and treatment of primary bone sarcoma of the pelvis

BACKGROUND

Symptoms arising from primary bone sarcoma of the pelvic girdle are often insidious in onset and nonspecific in nature. To make the subtle initial signs and symptoms of these tumors more apparent to clinicians, we studied a cohort of patients who had a primary bone sarcoma of the pelvic girdle. Our purpose was to describe the initial clinical findings and to evaluate the duration, frequency, and implications of delays in the treatment of these tumors.

METHODS

We retrospectively analyzed the data on sixty-eight patients who had a primary bone sarcoma of the pelvic girdle. The data that we reviewed included demographic characteristics; histological diagnosis; anatomical location, size, and stage of the tumor; characteristics of the biopsy specimen; duration and description of symptoms before an accurate diagnosis was made; delay before recognition of the tumor on radiographs; results of diagnostic imaging; inaccurate diagnoses; type of intervention based on these inaccurate diagnoses; and outcome with regard to survival. There were forty high-grade sarcomas and twenty-eight low-grade sarcomas.

RESULTS

Excluding two asymptomatic patients in whom the sarcoma was noted incidentally, the average duration of symptoms before an accurate diagnosis was made was ten months (median, six months; range, one month to four years). Common symptoms and findings on physical examination included pain in the buttock (twenty-three patients; 35 percent), a mass (twenty patients; 30 percent), sciatica (nineteen patients; 29 percent), pain in the hip (seventeen patients; 26 percent), pain in the groin (thirteen patients; 20 percent), and low-back pain (fourteen patients; 21 percent). In thirty (44 percent) of the sixty-eight patients, the pelvic sarcoma was not recognized initially and an inaccurate diagnosis was made. The misdiagnoses included a herniated lumbar disc, spinal stenosis, spondylolisthesis, tendinitis, bursitis, an inguinal hernia, a stress fracture, a pilonidal cyst, a recurrent urinary-tract infection, and degenerative arthritis of the spine, hip, and knee. Inappropriate treatment for these misdiagnoses included seven operative procedures (two laminectomies, two debridements, one hip arthrotomy, one total knee replacement, and one inguinal herniorrhaphy), six courses of nonsteroidal anti-inflammatory medications, five chiropractic adjustments, four trials of physical therapy, and three local injections of steroids. It took an average of seven months for the clinicians to arrive at the diagnosis of primary pelvic sarcoma. With the numbers available, no significant association between the duration of symptoms before an accurate diagnosis was made and the grade or the stage of the tumor could be detected. In addition, no association between the duration of symptoms and the survival of the patient (p = 0.54) could be determined, with univariate analysis. The grade and the stage of the tumor were strongly associated with the outcome, with a low tumor grade proving to be a favorable prognostic indicator for survival (p = 0.006).

CONCLUSIONS

Patients who have a primary bone sarcoma of the pelvis often have had symptoms for a long duration that mimic those of more commonly encountered non-neoplastic musculoskeletal conditions. When a patient has symptoms that appear to be out of the ordinary, particularly refractory pain or pain at rest, physicians should include the pelvic girdle in the evaluation and should carefully examine a high-quality radiograph of the entire pelvis.

Control of viremia in simian immunodeficiency virus infection by CD8+ lymphocytes

Clinical evidence suggests that cellular immunity is involved in controlling human immunodeficiency virus-1 (HIV-1) replication. An animal model of acquired immune deficiency syndrome (AIDS), the simian immunodeficiency virus (SIV)-infected rhesus monkey, was used to show that virus replication is not controlled in monkeys depleted of CD8+ lymphocytes during primary SIV infection. Eliminating CD8+ lymphocytes from monkeys during chronic SIV infection resulted in a rapid and marked increase in viremia that was again suppressed coincident with the reappearance of SIV-specific CD8+ T cells. These results confirm the importance of cell-mediated immunity in controlling HIV-1 infection and support the exploration of vaccination approaches for preventing infection that will elicit these immune responses.

Association of simian virus 40 with a central nervous system lesion distinct from progressive multifocal leukoencephalopathy in macaques with AIDS

The primate polyomavirus SV40 is known to cause interstitial nephritis in primary infections and progressive multifocal leukoencephalopathy (PML) upon reactivation of a latent infection in SIV-infected macaques. We now describe a second central nervous system manifestation of SV40: a meningoencephalitis affecting cerebral gray matter, without demyelination, distinct from PML. Meningoencephalitis appears also to be a primary manifestation of SV40 infection and can be seen in conjunction with SV40-induced interstitial nephritis and pneumonitis. The difference in the lesions of meningoencephalitis and PML does not appear to be due to cellular tropism, as both oligodendrocytes and astrocytes are infected in PML and meningoencephalitis, as determined by in situ hybridization or immunohistochemistry for SV40 coupled with immunohistochemistry for cellular determinants. This is further supported by examination of SV40 nucleic acid sequences from the ori-enhancer and large-T-antigen regions, which reveals no tissue-or lesion-specific variation in SV40 sequences.

Disabled is a putative adaptor protein that functions during signaling by the sevenless receptor tyrosine kinase

DRK, the Drosophila homolog of the SH2-SH3 domain adaptor protein Grb2, is required during signaling by the sevenless receptor tyrosine kinase (SEV). One role of DRK is to provide a link between activated SEV and the Ras1 activator SOS. We have investigated the possibility that DRK performs other functions by identifying additional DRK-binding proteins. We show that the phosphotyrosine-binding (PTB) domain-containing protein Disabled (DAB) binds to the DRK SH3 domains. DAB is expressed in the ommatidial clusters, and loss of DAB function disrupts ommatidial development. Moreover, reduction of DAB function attenuates signaling by a constitutively activated SEV. Our biochemical analysis suggests that DAB binds SEV directly via its PTB domain, becomes tyrosine phosphorylated upon SEV activation, and then serves as an adaptor protein for SH2 domain-containing proteins. Taken together, these results indicate that DAB is a novel component of the SEV signaling pathway.

Src64 is required for ovarian ring canal morphogenesis during Drosophila oogenesis

The Src family of protein tyrosine kinases have been implicated as important regulators of cellular proliferation, differentiation and function. In order to understand further the role of Src family kinases, we have generated loss-of-function mutations in Src64, one of two Src family kinases known in Drosophila melanogaster. Animals with reduced Src64 function develop normally and are fully viable. However, Src64 female flies have reduced fertility, which is associated with the incomplete transfer of cytoplasm from nurse cells to the developing oocyte. Analysis of Src64 egg chambers showed defects in the ring canals that interconnect the oocyte and its 15 associated nurse cells. Src64 ring canals fail to accumulate the high levels of tyrosine phosphorylation that are normally present. Despite the reduced tyrosine phosphorylation, known ring canal components such as filamentous actin, a ring canal-specific product of the hu-li tai shao gene, and the kelch protein localize properly. However, Src64 ring canals are reduced in size and frequently degenerate. These results indicate that Src64 is required for the proper growth and stability of the ovarian ring canals.