Helicobacter pylori gastritis in children is associated with a regulatory T-cell response

BACKGROUND & AIMS

Helicobacter pylori infection in children infrequently causes gastroduodenal mucosal ulceration. Because H pylori induces T-cell dependent gastric inflammation in adults and T regulatory (Treg) cells suppress T-cell-dependent pathology, we evaluated gastric histopathology and Treg cell responses in H pylori-infected children and adults.

METHODS

Gastric tissue from 36 children and 79 adults with abdominal symptoms in Santiago, Chile, was evaluated prospectively for H pylori bacteria and histopathology using the Sydney classification and Treg responses using immunoassay, immunohistochemistry, and real-time polymerase chain reaction.

RESULTS

Eighteen (50%) of the children and 51 (65%) of the adults were infected with H pylori. Children and adults were colonized with similar levels of H pylori. However, the level of gastritis in the children was reduced substantially compared with that of the adults (P < .05). Coincident with reduced gastric inflammation, the number of Treg cells and levels of Treg cytokines (transforming growth factor [TGF]-beta1 and interleukin-10) were increased markedly in the gastric mucosa of H pylori-infected children compared with that of infected adults (P < .03 and < .05, respectively). Also, H pylori infection in the children was associated with markedly increased levels of gastric TGF-beta1 and interleukin-10 messenger RNA. Importantly, gastric TGF-beta1 in H pylori-infected children localized predominantly to mucosal CD25(+) and Foxp3(+) cells, indicating a Treg source for the TGF-beta1.

CONCLUSIONS

Gastric pathology is reduced and local Treg cell responses are increased in H pylori-infected children compared with infected adults, suggesting that gastric Treg cell responses down-regulate the inflammation and ulceration induced by H pylori in children.

Role of aberrant glycosylation of IgA1 molecules in the pathogenesis of IgA nephropathy

Studies of the properties of immune complexes (IC) in the circulation, urine, and mesangium of IgA nephropathy (IgAN) patients have provided data relevant to the pathogenesis of this disease. IC contain predominantly polymeric IgA1 molecules which are deficient in galactose (Gal) residues on O-linked glycan chains in the hinge region (HR) of their heavy (H) chains. As a result of this aberrancy, a novel antigenic determinant(s) involving N-acetylgalactosamine (GalNAc) and perhaps sialic acid (SA) of O-linked glycans is generated and recognized by naturally occurring GalNAc-specific antibodies. Thus, IC in IgAN consist of Gal-deficient IgA1 molecules as an antigen, and GalNAc-specific IgG and/or IgA1 as an antibody. IgG antibodies to Gal-deficient IgA1 are probably induced by cross-reactive microbial antigens; they are present at variable levels not only in humans with or without IgAN but also in many phylogenetically diverse vertebrate species. Incubation of human mesangial cells with IC from sera of IgAN patients indicated that stimulation of cellular proliferative activity was restricted to the large (>800 kDa) complexes. These findings suggest that experimental approaches that prevent the formation of large Gal-deficient IgA1-IgG IC may be applied ultimately in an immunologically mediated therapy.

Atrial natriuretic peptide inhibits transforming growth factor beta-induced Smad signaling and myofibroblast transformation in mouse cardiac fibroblasts

This study tested the hypothesis that activation of atrial natriuretic peptide (ANP)/cGMP/protein kinase G signaling inhibits transforming growth factor (TGF)-beta1-induced extracellular matrix expression in cardiac fibroblasts and defined the specific site(s) at which this molecular merging of signaling pathways occurs. Left ventricular hypertrophy and fibrosis, collagen deposition, and myofibroblast transformation of cardiac fibroblasts in response to pressure overload by transverse aortic constriction were exaggerated in ANP-null mice compared with wild-type controls. ANP and cGMP inhibited TGF-beta1-induced myofibroblast transformation, proliferation, collagen synthesis, and plasminogen activator inhibitor-1 expression in cardiac fibroblasts isolated from wild-type mice. Following pretreatment with cGMP, TGF-beta1 induced phosphorylation of Smad3, but the resultant pSmad3 could not be translocated to the nucleus. pSmad3 that had been phosphorylated with recombinant protein kinase G-1alpha was analyzed by use of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and ion trap tandem mass spectrometry. The analysis revealed phosphorylation of Ser309 and Thr388 residues, sites distinct from the C-terminal Ser423/425 residues that are phosphorylated by TGF-beta receptor kinase and are critical for the nuclear translocation and down-stream signaling of pSmad3. These results suggest that phosphorylation of Smad3 by protein kinase G is a potential molecular mechanism by which activation of ANP/cGMP/protein kinase G signaling disrupts TGF-beta1-induced nuclear translocation of pSmad3 and downstream events, including myofibroblast transformation, proliferation, and expression of extracellular matrix molecules in cardiac fibroblasts. We postulate that this process contributes to the antifibrogenic effects of the natriuretic peptide in heart.

Genistein attenuates the hypertensive effects of dietary NaCl in hypertensive male rats

Diets high in polyphenols may protect estrogen-depleted women and rats from hypertension, but there is little evidence for this beneficial effect in males. On a polyphenol-free diet, ovariectomized spontaneously hypertensive rats (SHRs), high dietary NaCl increases arterial pressure, and this effect is greatly blunted by a soy-based diet. High NaCl diets also elevate arterial pressure in male SHRs, and pilot studies indicated that soy polyphenols blunt this effect. The present studies tested the hypothesis that genistein (the primary polyphenol in soy) reduces NaCl-sensitive hypertension in young, male stroke-prone SHRs (SHR-SP, a very NaCl-sensitive strain of SHR). Seven-week-old male SHR-SPs were placed on polyphenol-free diets with or without normal dietary amounts of genistein [0.06% (wt/wt)] and containing high (4%), moderate (2%), or basal (0.7%) NaCl. SHR-SP on the genistein-free diet displayed a dose-related increase in arterial pressure in response to dietary NaCl, and dietary genistein blunted this response. Ganglionic blockade with hexamethonium reduced arterial pressure to similar levels in all six groups, suggesting that the antihypertensive effects of genistein are influenced by the autonomic nervous system. We further hypothesized that genistein, like estrogen, would improve insulin sensitivity and lipid profiles. Thus, in study 2, 7-wk-old male SHR-SP were placed on high (6%) or basal (0.7%) NaCl diets with or without genistein (0.06%). Dietary genistein reduced plasma insulin and insulin resistance in SHR-SP on a high NaCl diet and decreased plasma cholesterol and triglycerides in SHR-SP on the basal NaCl diet. Thus, in male SHR-SP, dietary genistein blunts NaCl-sensitive hypertension, and these effects may be regulated, in part, by the autonomic nervous system and/or metabolic mechanisms.

Cytomegalovirus blocks intestinal stroma-induced down-regulation of macrophage HIV-1 infection

Intestinal macrophages, unlike macrophages from other tissues, do not support HIV-1 infection or produce proinflammatory cytokines. In vitro studies suggest this unique, functional phenotype is a result of the exposure of newly recruited blood monocytes to intestinal stromal products. However, in AIDS-related CMV colitis, mucosal macrophages express HIV-1 and proinflammatory cytokines. Therefore, we investigated the mechanism by which CMV confers permissiveness to HIV-1 and cytokine production on intestinal macrophages. We show that intestinal stroma-conditioned media (S-CM) down-regulated monocyte-derived macrophage infection by HIV-1 (pseudotyped with YU2 envelope or vesicular stomatitis virus glycoprotein) and production of TNF-alpha, but preinfection of the cells with CMV reversed this down-regulation, enhancing HIV-1 infection, p24 production, and TNF-alpha release. The ability of CMV to reverse S-CM down-regulation of macrophage HIV-1 infection was blocked by anti-TNF-alpha antibodies and over-ridden by exogenous TNF-alpha. Immunohistochemical analysis of monocyte-derived macrophages exposed to CMV and HIV-1 (YU2 pseudotype) revealed that the cells infrequently contained CMV and HIV-1 viral proteins. In addition, analysis of colon tissue sections from HIV-1-infected patients with CMV colitis showed that some macrophage-like cells contained CMV and TNF-alpha proteins, others contained HIV-1 and TNF-alpha proteins, but cells infrequently contained CMV and HIV-1 proteins. These results indicate that CMV blocks stromal product inhibition of HIV-1 infection in macrophages, and this inhibition is mediated, at least in part, by CMV-induced TNF-alpha acting in trans to enhance HIV-1 infection.

Estrogen modulates TNF-α-induced inflammatory responses in rat aortic smooth muscle cells through estrogen receptor-β activation

We have previously shown that 17β-estradiol (E2) attenuates responses to endoluminal injury of the rat carotid artery, at least in part, by decreasing inflammatory mediator expression and neutrophil infiltration into the injured vessel, with a major effect on the neutrophil-specific chemokine cytokine-induced neutrophil chemoattractant (CINC)-2β. Current studies tested the hypothesis that activated rat aortic smooth muscle cells (RASMCs) express these same inflammatory mediators and induce neutrophil migration in vitro and that E2 inhibits these processes by an estrogen receptor (ER)-dependent mechanism. Quiescent RASMCs treated with E2, the ERα-selective agonist propyl pyrazole triol (PPT), the ERβ-selective agonist diarylpropiolnitrile (DPN), or vehicle for 24 h were stimulated with tumor necrosis factor (TNF)-α and processed for real-time RT-PCR, ELISA, or chemotaxis assays 6 h later. TNF-α stimulated and E2 attenuated mRNA expression of inflammatory mediators, including P-selectin, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, monocyte chemoattractant protein (MCP)-1, and CINC-2β. DPN dose dependently attenuated TNF-α-induced mRNA expression of CINC-2β, whereas PPT had no effect. The anti-inflammatory effects of DPN and E2 were blocked by the nonselective ER-inhibitor ICI-182,780. ELISA confirmed the TNF-α-induced increase and E2-induced inhibition of CINC-2β protein secretion. TNF-α treatment of RASMCs produced a twofold increase in neutrophil chemotactic activity of conditioned media; E2 and DPN treatment markedly inhibited this effect. E2 inhibits activated RASMC proinflammatory mediator expression and neutrophil chemotactic activity through an ERβ-dependent mechanism.

Human breast fibroblasts inhibit growth of the MCF10AT xenograft model of proliferative breast disease

Stromal fibroblasts are important for normal breast homeostasis and regulation of epithelial growth; however, this regulatory function is altered during carcinogenesis. To study the role of fibroblasts in the development of breast cancer, fibroblasts derived from normal breast (NAFs) were incorporated into the MCF10AT xenograft model of progressive proliferative breast disease. The persistence of human NAFs in xenografts was established by intracellular labeling and tyramide-coupled fluorescent in situ hybridization. Overall, the number of MCF10AT epithelial structures was decreased, and the rate of epithelial cell apoptosis was increased in xenografts containing NAFs. However, these changes were primarily in low-grade epithelial structures, corresponding to normal or mildly hyperplastic ductal epithelium. The level and rate of apoptosis of high-grade epithelial structures, corresponding to in situ and invasive carcinoma, were not consistently altered by NAFs. In addition, there was variability in the growth-inhibitory capacity of NAFs derived from different individuals. NAFs induced changes in the morphology of high-grade MCF10AT structures and in xenograft stroma, including the composition of extracellular matrix, and increased angiogenesis and lymphocytic infiltration. These findings imply that NAFs can inhibit the growth of normal and hyperplastic epi-thelium but are less able to regulate the more transformed epithelial cells that arise during carcino-genesis.

A Prospective Blinded Evaluation of the Accuracy of Frozen Section for the Surgical Management of Endometrial Cancer

OBJECTIVE

To prospectively evaluate in a blinded fashion the accuracy of frozen section in endometrial cancer.

METHODS

Sixty patients with endometrial cancer or complex atypical hyperplasia were consecutively enrolled. Intraoperatively, a frozen section was obtained, processed, and stored for interpretation by blinded pathologists. Final pathologic diagnosis was conducted in the usual fashion with the pathologists blinded to frozen results. Histologic grade and myometrial invasion on frozen section was correlated with final pathology.

RESULTS

Median age was 61 years (range, 39-82 years). Fifty-seven percent of patients were white, and mean body mass index was 40 mg/kg2. Depth of invasion on frozen correlated with final pathology in 67% (95% confidence interval [CI] 55-79%). Twenty-eight percent (95% CI 17-39%) of patients were upstaged from frozen to final. Patients with no invasion on frozen were upstaged in 46% (95% CI 28-64%). Histologic grade on frozen correlated with final pathology in 58% (95% CI 46-70%); 38% (95% CI 26-50%) of patients were upgraded by final grade. Patients with frozen grade 1 histology or less were upgraded in 61% (95% CI 45-77%). Clinically relevant upstaging occurred in 11 patients (18%) (95% CI 8-28%).

CONCLUSION

Frozen section for histologic grade and depth of myometrial invasion in endometrial cancer correlates poorly with final pathology. Because a large number of patients are potentially understaged with the use of frozen section with a subsequent risk of over and under treatment, we recommend consideration of comprehensive surgical staging for all patients with endometrial cancer.

LEVEL OF EVIDENCE

II-2.

Recurrence of endometrial adenocarcinoma in a prior Bartholin's cyst marsupialization incision

BACKGROUND

Endometrial cancer recurrences in surgical incisions are rare and thought to be due to seeding of the area with microscopic disease at the time of original surgery.

CASE

A 53-year-old woman underwent a dual procedure of a marsupialization of a benign bartholin's cyst with a hysteroscopic dilation and curettage for postmenopausal bleeding and received the diagnosis of endometrial adenocarcinoma. Final pathology from subsequent hysterectomy and staging procedure demonstrated a surgical Stage IB Grade 1 endometrial cancer. An isolated recurrence of disease in her marsupialization scar was discovered 10 months after her staging procedure.

CONCLUSION

This case represents the only described endometrial cancer recurrence in a Bartholin's gland which was contaminated at the time of the original hysteroscopy and dilation and curettage.

ANP signaling inhibits TGF-beta-induced Smad2 and Smad3 nuclear translocation and extracellular matrix expression in rat pulmonary arterial smooth muscle cells

Atrial natriuretic peptide (ANP) and transforming growth factor (TGF)-beta play important counterregulatory roles in pulmonary vascular adaptation to chronic hypoxia. To define the molecular mechanism of this important interaction, we tested whether ANP-cGMP-protein kinase G (PKG) signaling inhibits TGF-beta1-induced extracellular matrix (ECM) expression and defined the specific site(s) at which this molecular merging of signaling pathways occurs. Rat pulmonary arterial smooth muscle cells (PASMCs) were treated with ANP (1 muM) or cGMP (1 mM) with or without pretreatment with PKG inhibitors KT-5823 (1 muM) or Rp-8-bromo-cGMP (Rp-8-Br-cGMP 50 muM), then exposed to TGF-beta1 (1 ng/ml) for 5-360 min (for pSmad nuclear translocation and protein analysis) or 24 h (for ECM mRNA expression). Nuclear translocation of pSmad2 and pSmad3 was assessed by fluorescent confocal microscopy. ANP and cGMP inhibited TGF-beta1-induced pSmad2 and pSmad3 nuclear translocation and expression of periostin, osteopontin, and plasminogen activator inhibitor-1 mRNA and protein, but not TGF-beta1-induced phosphorylation of Smad2 and Smad3. KT-5823 and Rp-8-Br-cGMP blocked ANP/cGMP-induced activation of PKG and inhibition of TGF-beta1-stimulated nuclear translocation of pSmad2 and pSmad3 in PASMCs. These results reveal for the first time a precise site at which ANP-cGMP-PKG signaling exerts its antifibrogenic effect on the profibrogenic TGF-beta1 signaling pathway: by blocking TGF-beta1-induced pSmad2 and pSmad3 nuclear translocation and ECM expression in PASMCs. Blocking nuclear translocation and subsequent binding of pSmad2 and pSmad3 to TGF-beta-Smad response elements in ECM genes may be responsible for the inhibitory effects of ANP on TGF-beta-induced expression of ECM molecules.

Mucosal IL-8 and TGF-beta recruit blood monocytes: evidence for cross-talk between the lamina propria stroma and myeloid cells

The lamina propria of the gastrointestinal mucosa contains the largest population of mononuclear phagocytes in the body, yet little is known about the cellular mechanisms that regulate mononuclear cell recruitment to noninflamed and inflamed intestinal mucosa. Here, we show that intestinal macrophages do not proliferate. We also show that a substantial proportion of intestinal macrophages express chemokine receptors for interleukin (IL)-8 and transforming growth factor-beta (TGF-beta), and a smaller proportion expresses receptors for N-formylmethionyl-leucyl-phenylalanine and C5a, but, surprisingly, they do not migrate to the corresponding ligands. In contrast, autologous blood monocytes, which express the same receptors, do migrate to the ligands. Blood monocytes also migrate to conditioned medium (CM) derived from lamina propria extracellular matrix, which we show contains IL-8 and TGF-beta that are produced by epithelial cells and lamina propria mast cells. This migration is specific to IL-8 and TGF-beta, as preincubation of the stroma-CM with antibodies to IL-8 and TGF-beta significantly blocked monocyte chemotaxis to the stromal products. Together, these findings indicate that blood monocytes are the exclusive source of macrophages in the intestinal mucosa and underscore the central role of newly recruited blood monocytes in maintaining the macrophage population in noninflamed mucosa and in serving as the exclusive source of macrophages in inflamed mucosa.

Nasal colonization with Streptococcus pneumoniae includes subpopulations of surface and invasive pneumococci

We demonstrated that during colonization with Streptococcus pneumoniae the nasal mucosal tissues of mice support two populations of pneumococci. Transparent-phase pneumococci can be readily washed from the outer surface, while a second population composed of primarily opaque-phase pneumococci is released only by homogenization of the nasal tissue. The fact that the opaque phase has previously been associated with invasion and the fact that opaque-phase pneumococci were released by homogenization of previously washed nasal tissue suggest that the opaque-phase pneumococci may have invaded the nasal tissue. Consistent with this hypothesis was our observation that there was inflammation in portions of the nasal mucosa of the colonized mice but not in the mucosa of noncolonized mice, but this observation did not prove the hypothesis. If the opaque-phase pneumococci released from the nasal tissue were from within the tissue and/or if resistance of the opaque-phase subpopulation to antibody, complement, and phagocytes is essential for long-term carriage, it seems likely that the virulence factors of S. pneumoniae that are necessary for killing humans exist to facilitate carriage. Although this speculation is unproven, the observation that there are separate populations of pneumococci during colonization may help guide future attempts to understand the biology of nasal colonization by this pathogen.

IgA1-containing immune complexes in IgA nephropathy differentially affect proliferation of mesangial cells

BACKGROUND

Sera of patients with IgA nephropathy (IgAN) contain circulating immune complexes (CIC) composed of galactose-deficient IgA1 complexed with antiglycan antibodies. The role of these CIC in the pathogenesis of IgAN is not known.

METHODS

We studied how proliferation of cultured mesangial cells (MC) is affected by CIC prepared from sera of IgAN patients and healthy control subjects using size-exclusion chromatography. CIC-containing fractions were added to serum-starved MC in culture, and cell proliferation was measured using (3)H-thymidine incorporation. The results were confirmed by staining MC using an antibody against proliferating cell nuclear antigen.

RESULTS

The incubation of starved MC with serum fractions with M(r) 800 to 900 kD, rich with galactose-deficient IgA1, stimulated proliferation, while fractions with smaller complexes were inhibitory. Furthermore, CIC-containing larger molecular mass fractions isolated from serum of an IgAN patient collected during an episode of macroscopic hematuria stimulated MC proliferation more than CIC obtained during a subsequent quiescent phase. To examine the role of IgA, we removed IgA1 from serum before fractionation. The resultant IgA1-depleted fractions were devoid of stimulatory IgA-CIC. Sera of IgAN patients were also fractionated after addition of desialylated galactose-deficient polymeric IgA1 to form additional immune complexes. Supplementation with a small quantity of this IgA1 increased cellular proliferation in assays using serum fractions of M(r)>/=800 to 900 kD; uncomplexed IgA1 did not affect MC proliferation significantly. In contrast, supplementation with a larger quantity of this IgA1 inhibited cellular proliferation in assays using serum fractions of M(r) 700 to 800 kD.

CONCLUSION

Overall, these findings suggest that CIC containing aberrantly glycosylated IgA1 affect proliferation of MC in vitro and, thus, likely play a role in the pathogenesis of IgAN.

Spinal Extradural Arachnoid Cyst Causing Cord Compression in a 15-Year-Old Girl: A Case Report

The authors describe the case of a fifteen-year-old girl with progressive paraparesis of the lower limbs that was caused by an intraspinal extradural dorsal arachnoid cyst at the level of Th 3-6. Diagnosis was established with MRI and MRI myelography. The latter revealed the CSF-like content of the cyst. The patient underwent laminotomy and en bloc resection of the cyst. Ligation of the pedicle of the cyst was done with laminoplasty. Quick and complete recovery was observed after surgery.

First results from the Cryogenic Dark Matter Search in the Soudan Underground Laboratory

We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2.

AL-amyloidosis is underdiagnosed in renal biopsies

BACKGROUND

Renal amyloidosis is associated with a variety of underlying disease processes. Although amyloid is identical in appearance in these diseases, the precursor proteins are different. Immunofluorescence microscopy has been used as the primary tool in the diagnostic evaluation of the underlying cause of renal AL-amyloidosis. The purpose of this study was to document the sensitivity of immunofluorescence microscopy in AL-amyloidosis.

METHODS

We reviewed 36 renal biopsies from patients with amyloidosis collected in two medical centres. All biopsies showed characteristic fibrillary deposits of amyloid on electron microscopy and stained positive with Congo red or Thioflavin-T.

RESULTS

Among these 36 patients, immunofluorescence staining for lambda and kappa light chains was negative or equivocal in 14 biopsies. Of these 14 patients, two patients had evidence of AA-amyloidosis. Twelve patients were found subsequently to have a plasma cell dyscrasia or multiple myeloma with monoclonal immunoglobulin and/or free light chains on immunofixation electrophoresis of urine or serum, and with evaluation of the bone marrow. Thus, 12 of 34 patients (35.3%) with proven AL-amyloidosis had negative immunofluorescence staining for kappa and lambda light chains.

CONCLUSIONS

The data demonstrated the low sensitivity of immunofluorescence microscopy in the detection of AL-amyloidosis in the kidney and underscore the need to pursue additional diagnostic studies to identify this problem.

Estradiol and Progestins Differentially Modulate Leukocyte Infiltration After Vascular Injury

Background— Inflammation plays an important role in the response to endoluminal vascular injury. Estrogen (17β-estradiol, E 2 ) inhibits neointima formation in animal models, and the progestin medroxyprogesterone acetate (MPA) blocks this effect. This study tested the hypothesis that E 2 inhibits the migration of inflammatory cells, particularly granulocytes, into the rat carotid arteries after acute endoluminal injury and that MPA blocks this effect.

Methods and Results— Ovariectomized rats were randomly divided into subgroups and treated with E 2 , MPA, E 2 +MPA, or vehicle and subjected to balloon injury of the right carotid artery. After 1, 3, or 7 days, rats were euthanized, and carotid arteries (injured and control) were analyzed for inflammatory cells by flow cytometry. At 1 day, granulocytes (HIS48 + and CD45 + ), monocyte/macrophages (Mar1 + and CD45 + ), and T lymphocytes (CD3 + and CD45 + ) were increased 26-fold, 12-fold, and 3-fold, respectively, in injured compared with contralateral control arteries of vehicle-treated rats. Granulocytes and monocyte/macrophages decreased markedly by 3 days. E 2 reduced the granulocyte and monocyte/macrophage populations of injured vessels by ≈50% and increased T lymphocytes. MPA had no independent effect on inflammatory cells but completely blocked the effect of E 2 . Immunohistochemical examination verified these findings and localized inflammatory cells to the adventitial and periadventitial domains of injured vessels.

Conclusions— E 2 may limit the neointimal response to endoluminal vascular injury, at least in part, by limiting leukocyte entry from adventitial/periadventitial tissues into injured vessels early in the injury response.

Heat exchange between the organism and environment under conditions of weightlessness; methodical approach

The spontaneous streaming of air around surfaces of warm bodies conditioned by gravitation is missing in the weightless condition. This implies a change in the thickness of the surface air layer and its interference with the heat output of an organism. The paper describes the use of an electric dynamic katathermometer (EDK) for automatic and continuous scanning of heat output and presents results of measuring basic characteristics of the surface layer under defined laboratory conditions, and their relation to heat output.

Immunizations with pneumococcal surface protein A and pneumolysin are protective against pneumonia in a murine model of pulmonary infection with Streptococcus pneumoniae

Intranasal infection of mice with certain strains of capsular group 19 Streptococcus pneumoniae can result in focal pneumonia in the absence of bacteremia. Using this model of murine pneumonia, we demonstrated that immunization with recombinant forms of either pneumococcal surface protein A (PspA) or PdB (a genetically detoxified derivative of pneumolysin) elicited significant protection against focal pulmonary infection. This may be the first demonstration that a proposed vaccine antigen can protect against pneumococcal pneumonia. The best protection was obtained by immunizing mice with a mixture of PspA and PdB, indicating that the protection elicited by these antigens can complement each other. This result is in agreement with previous studies that used pneumococcal sepsis and nasal colonization models and demonstrate that the best protein vaccines for prevention of infection may be those that include more than one protection-eliciting pneumococcal protein.

Respiratory gas exchange as an indicator of changed radioresistance in mammals

The paper deals with the problem of detection of radio-protective effects during irradiation. The method used is based on the fact that the known effective pharmacological and chemical radioprotectives (aminoethylthiouronium bromide HBr (AET), cystamine, sodium fluoroacetate (FAc), 5-hydroxytryptamine (5-HT), 5-methoxytryptamine (5-MT) and others) interfere directly or indirectly with enzymatic steps in energy metabolism of the organism. In mammals they induce at the same time an increase of resistance against ionizing radiation and a decrease in the respiratory gas exchange expressed by a depressed oxygen consumption. In experiments carried out on male mice of the H strain and male rats of the Wistar strain it was found that animals respiring a hypoxic mixture (5-8% O2, STPD), have a lower oxygen consumption during the period of increased radioresistance similar to that seen during the effect of radioprotective drugs. This finding is of practical importance as it enables one to evaluate quantitatively the effect of radioprotective measures (including the hypoxia) in individual experimental animals during the course of irradiation.

Mitochondrial targets of oxidative stress during renal ischemia/reperfusion

Endogenous tyrosine nitration and inactivation of manganese superoxide dismutase (MnSOD) has previously been shown to occur in both human and rat chronic renal allograft rejection. To elucidate the time course of MnSOD inactivation and mitochondrial dysfunction at earlier times during renal transplantation, we developed a rodent model of renal ischemia/reperfusion (I/R). Renal function was significantly impaired at 16 h reperfusion following 30 min of warm ischemia. Tyrosine nitration of specific mitochondrial proteins, MnSOD and cytochrome c, occurred at the earliest time point examined, an event that preceded significant renal injury. Interestingly, a small percentage of both mitochondrial proteins were also located in the cytosol. This leakage and decreased adenosine 5(')-triphosphate levels indicate loss of mitochondrial membrane integrity during renal I/R. Inactivation of MnSOD occurred rapidly in this model of renal I/R, suggesting that loss of MnSOD activity leads to further renal injury and nitration of other mitochondrial targets.

Multiple Langerhans cell nodules in an incidental thymectomy

The isolated appearance of Langerhans cell histiocytosis in the thymus is quite rare. We report the finding of multiple small Langerhans cell nodules in the thymus of an 11-month-old infant who had undergone thymectomy in the course of surgical correction of tetralogy of Fallot. The subtle appearance of some of these nodules and aggregates was unlike the pattern of massive thymic infiltration seen in 7 previously reported cases of thymic Langerhans cell histiocytosis in childhood. This difference led us to consider whether these aggregates might be common in the thymus but overlooked in thymus glands removed incidental to cardiac surgery. We examined histologic material from 22 sequential thymectomy specimens removed during cardiac surgery from infants and children. None (0/22) had cohesive aggregates of Langerhans cells, as were seen in the index patient's thymus. Our patient's small thymic nodules resemble more closely a pattern found in adult patients with myasthenia gravis who have been incidentally shown to have Langerhans cell histiocytosis.

Interactions of human mesangial cells with IgA and IgA-containing immune complexes

BACKGROUND

IgA nephropathy (IgAN) is characterized by IgA1-containing immune complexes in mesangial deposits and in the circulation. The circulating immune complexes (CIC) are composed of galactose- (Gal) deficient IgA1 and IgG or IgA1 antibodies specific for the Gal-deficient IgA1; interactions of these CIC with mesangial cells (MC) were studied.

METHODS

Binding, internalization, and catabolic degradation of myeloma IgA1 protein as a standard control and the isolated CIC were studied using human MC, hepatoma cell line HepG2 expressing the asialoglycoprotein receptor (ASGP-R), and monocyte-like cell line U937 expressing the Fc(alpha)-R (CD89). Biochemical and molecular approaches were used to assess expression of CD89 and ASGP-R by MC.

RESULTS

At 4 degrees C, radiolabeled IgA1 bound to MC and HepG2 cells in a dose-dependent and saturable manner. The binding was inhibited by IgA-containing CIC or excess IgA1 or its Fc fragment but not by the Fab fragment of IgA1. At 37 degrees C, the cell-bound IgA1 was internalized and catabolized. In addition to IgA1, HepG2 cells also bound (in a Ca2+-dependent manner), internalized, and catabolized asialoorosomucoid (ASOR), other asialo-(AS)-glycoproteins, and secretory component (SC). The binding by MC appeared to be restricted to IgA1 or AS-IgA1 and was not Ca2+-dependent. Furthermore, MC and HepG2 cells internalized and catabolized IgA1-containing CIC. Using RT-PCR with ASGP-R- or CD89-specific primers, mRNAs of the two respective genes were not detected in MC.

CONCLUSIONS

The data showed that the ability of MC to bind IgA1 and IgA1-containing CIC in vitro was mediated by an IgA receptor that was different from CD89 or ASGP-R and had a higher affinity for IgA-CIC than for uncomplexed IgA.

Comparison of standard and alternative prehospital resuscitation in uncontrolled hemorrhagic shock and head injury

BACKGROUND

Recently acquired data suggest that prehospital fluid resuscitation may worsen outcome of patients with penetrating torso trauma. In patients with head injury, delayed resuscitation (DR) could lead to secondary cerebral ischemia. We hypothesized that standard prehospital resuscitation (SPR) with lactated Ringer's solution or diaspirin cross-linked hemoglobin would reduce secondary cerebral ischemia compared with DR.

METHODS

Anesthetized swine were randomized to receive SPR, diaspirin cross-linked hemoglobin, or DR after cryogenic brain injury and uncontrolled hemorrhagic shock and studied for 70 minutes after the combined insults.

RESULTS

Hemorrhage volume was lowest in the DR group (p<0.05). There were no significant differences between the groups in systemic or cerebral oxygen delivery. Intracranial pressure was lower and cerebral perfusion pressure higher in the diaspirin cross-linked hemoglobin group compared with SPR (p<0.05). Lesion size was greatest in the SPR group, but the difference was not significant.

CONCLUSION

In this model, SPR leads to secondary cerebral ischemia. DR is no worse and may be superior to conventional prehospital resuscitation with lactated Ringer's solution.

Cerebrovascular reserve capacity many years after vasospasm due to aneurysmal subarachnoid hemorrhage. A transcranial Doppler study with acetazolamide test

BACKGROUND AND PURPOSE

Vasospasm in aneurysmal subarachnoid hemorrhage results in proliferative vasculopathy. Systemic hypertension also causes vascular hypertrophy. Both of these histological changes can lead to rigidity of the cerebrovascular system, reducing its autoregulatory capacity.

METHODS

Blood flow velocity (BFV) in the middle cerebral artery at rest and cerebrovascular reserve capacity (CVRC) (percent rise in BFV after acetazolamide stimulation) measured by means of transcranial Doppler sonography were studied many years after aneurysmal subarachnoid hemorrhage in patients with proven cerebral vasospasm (mean BFV > 160 cm/s). The BFV under resting conditions and the CVRC values of the ipsilateral and the contralateral hemispheres were measured in 29 patients (mean age, 43 years; mean follow-up, 4.6 years) and compared with those of control subjects.

RESULTS

Persistent high BFV (> 120 cm/s) was found in three patients in the peripheral branch of the ipsilateral middle cerebral artery. In the main trunks of the arteries of the anterior circle of Willis, BFV was normal in all cases. CVRC was normal in all patients (ipsilateral, 52 +/- 21%; contralateral, 56 +/- 17%); values did not differ significantly from each other or from the control value (45 +/- 18%). The higher value of CVRC on the contralateral side was found to be statistically significant in selected groups (hypertensive patients and patients with residual infarct on late CT).

CONCLUSIONS

Proliferative vasculopathy developed at the time of vasospasm must have resolved and did not reduce late vasoreactivity. Comorbidity with hypertension also did not seem to influence the late vasoreactivity toward normalization.

Production of a specific major histocompatibility complex class I-restricted epitope by ubiquitin-dependent degradation of modified ovalbumin in lymphocyte lysate

Peptide epitopes presented through class I major histocompatability complex (MHC class I) on the cell surface, are generated by proteolytic processing of protein-antigens in the cytoplasm. The length and amino acid sequence determine whether a given peptide can fit into the peptide binding groove of class I heavy chain molecules and subsequently be presented to the immune system. The mode of action of the processing pathway is therefore of great interest. To study the processing mechanism of MHC class I-restricted intracellular antigens, we reconstituted the proteolytic processing of a model antigen in a cell-free system. Incubation of oxidized and urea-treated OVA in lymphocyte lysate resulted in partial degradation of the antigen. Degradation of the antigen depended on the presence of ATP. Addition of methylated ubiquitin abolished the reaction which was then restored by addition of an excess of native ubiquitin, indicating that the breakdown of the antigen in lymphocyte lysate is mediated by the ubiquitin proteolytic system. Upon incubation of modified OVA in lymphocyte lysate, a specific antigenic peptide was generated. The peptide was recognized by cytotoxic T lymphocytes directed against OVA-derived, H-2Kb-restricted peptide (SIINFEKL), and by a monoclonal antibody that recognizes cell-bound Kb-SIINFEKL complexes. Formation of the peptide epitope depended on the presence of ATP and ubiquitin. These results indicate that proteolytic processing of modified OVA is carried out by the ubiquitin-mediated degradation system. The experimental system described provides a tool to analyze the molecular mechanisms underlying the generation of specific, MHC class I-restricted peptide epitopes.

Metabolism and Energetics of Lactococcus lactis during Growth in Complex or Synthetic Media

When Lactococcus lactis was grown in various complex or synthetic media, the fermentation of glucose remained homolactic whatever the medium used, with a global carbon balance of about 87%. Moreover, the nitrogen balance was not equilibrated, indicating that some amino acids led to the production of unknown nitrogen-containing carbon compounds while part of the glucose might contribute to anabolic pathways. In minimal medium containing six amino acids, a high concentration of serine was deaminated to pyruvate. This did not occur in more complete media, suggesting the presence of a regulation of this phenomenon by an amino acid. Ammonia produced during serine consumption was partly reconsumed after serine exhaustion. The values for biomass yield and biomass yield relative to ATP (Y(infATP)), the maximal growth rate, the specific rate of glucose consumption, and the corresponding rate of ATP synthesis all increased with the complexity of the medium, amino acid composition having the most pronounced effect. The Y(infATP) values were shown to range from 6.6 to 17.6 g of biomass(middot)mol of ATP(sup-1) on minimal and complex media.

Craniospinal irradiation for acute lymphoblastic leukemia with central nervous system disease at diagnosis: a report from the Children's Cancer Group

PURPOSE

This study attempted to determine if central nervous system (CNS) disease at diagnosis is a poor prognostic factor in children with acute lymphoblastic leukemia (ALL) and whether 6 Gy of spinal irradiation is an adequate dose for these patients.

METHODS AND MATERIALS

Previously the Children's Cancer Group (CCG) treated patients with ALL and CNS disease at diagnosis with cranio (24 Gy)-spinal (12 Gy) irradiation, as well as systemic and intrathecal chemotherapy. In a series of CCG trials completed in 1989 the spinal dose was empirically reduced to 6 Gy for patients receiving systemic chemotherapy with an intensive consolidation phase to limit hematopoietic toxicity. The spinal dose was left at 12 Gy for patients treated with a less intensive consolidation phase.

RESULTS

With a median follow-up for surviving patients of 74 months, the 5-year event-free survival for 53 patients with CNS disease at diagnosis was 69 +/- 13% (+/- 2 standard deviations), similar to the value obtained for 3364 patients without CNS disease, 67 +/- 2%. Corresponding values for 5-year survival were 77 +/- 12% and 80 +/- 1%, and for freedom from isolated first CNS relapse, were 90 +/- 9% and 94 +/- 1%. Event-free survival, survival, and freedom from isolated first CNS relapse in the 6-Gy group were as good as in the 12-Gy group.

CONCLUSION

CNS disease at diagnosis is not a poor prognostic factor for children with ALL who are treated with intensive systemic chemotherapy, craniospinal irradiation, and intrathecal chemotherapy. Six Gy is an adequate dose of spinal irradiation for these patients.

Nonoccupational determinants of blood lead concentrations in a general population

We investigated the influence of various nonoccupational factors on blood lead levels (PbB) in a sample from the general population of southern Germany. Some 1703 men and 1661 women, aged 28-67 years, were examined in the first follow-up examination of the MONICA Augsburg cohort study in 1987-1988. Their mean PbB was 90 micrograms/l (SD:35.9) for men and 65 micrograms/l (26.4) for women. Only 5% of the men and 1% of all women exceeded a PbB level of 150 micrograms/l indicating low-level lead exposure in this population. Blood lead was significantly associated with haematocrit values (P < 0.001) and the shape of this association was curvilinear. Per gram of alcohol consumed, intake of beer had a lower impact on PbB than wine, presumably due to differential lead content in these alcoholic beverages. The alcohol-PbB associations were stronger for women than for men. The impact of smoking was generally moderate but again more prominent in women. In particular, the covariate adjusted odds ratios for women of childbearing age (28-47 years) to have PbB levels above 100 micrograms/l were 2.5 (95% confidence interval (CI): 1.3-4.7) for smoking versus non-smoking females, 2.6 (95% CI: 1.1-6.0) for women drinking up to 40 g alcohol/day compared to abstainers, and 8.9 (95% CI: 3.2-25.1) for those drinking more than 40 g alcohol/day. Other factors like age, body mass, rural place of residence, and education or job position, had only minor influences on PbB. We conclude that haematocrit values should always be considered as potential confounders in low-level lead exposure research. High alcohol consumption and cigarette smoking are strongly related to elevated blood lead concentrations in the general population and may thereby convey additional health hazards such as impaired child development or blood pressure elevations. This deserves proper public health recognition [corrected].

Our experience in the evaluation of the thermal comfort during the space flight and in the simulated space environment

The paper presents the results of the mathematical modelling the effects of hypogravity on the heat output by the spontaneous convection. The theoretical considerations were completed by the experiments "HEAT EXCHANGE 1" performed on the biosatellite "KOSMOS 936". In the second experiment "HEAT EXCHANGE 2" accomplished on the board of the space laboratory "SALYUT 6" was studied the effect of the microgravity on the thermal state of a man during the space flight. Direct measurement in weightlessness prowed the capacity of the developed electric dynamic katathermometer to check directly the effect of the microgravity on the heat output by the spontaneous convection. The role of the heat partition impairment's in man as by the microgravity, so by the inadequate forced convection are clearly expressed in changes of the skin temperature and the subjective feeling of the cosmonaut's thermal comfort. The experimental extension of the elaborated methods for the flexible adjustment of the thermal environment to the actual physiological needs of man and suggestions for the further investigation are outlined.

[Prognostication of man's health status in response to gravity-induced blood shifts based on continuous noninvasive measurement of arterial blood pressure using the Pen'iaz method]

Exposure to +Gz acceleration, orthostatic tilt tests and LBNP tests causes distinct blood shifts and deterioration of cerebral circulation. In this case syncope episodes may be prevented by continuous monitoring of circulation parameters, specifically arterial pressure (AP). Our investigations have shown that continuous AP measurement by the Penjaz noninvasive technique may help earlier prediction of the health status in response to gravity-induced blood shifts. In this situation the development of a pre-collapse state is preceded by an emergence of distinct AP waves of the second-third order accompanied by a critical drop of pulse pressure. It is concluded that continuous AP measurement in the finger according to the Penjaz noninvasive technique holds promise as a medical monitoring method in a altered gravitational field.

[Comparison of cytotoxicity of a chemical and a photopolymerizing composite filling material in a in vitro experiment]

The authors comparise the toxicity of a photopolymerizing (Silux 3M) and a chemical polymerizing (Silar 3M) composite by unspecific application on an in vitro cell culture of a permanent HEp-2-line. It was observed that a greater and more extensive injury was caused by the photopolymerizing material.

Developmental orofacial deficits associated with multimodal cancer therapy: case report

Multimodal cancer therapy for pediatric head and neck tumors may be associated with significant developmental orofacial morbidity. This report details these effects in a child (C.I.) diagnosed at 2.5 years of age with a rhabdomyosarcoma, primary to the left buccinator. This case is of interest as C.I. has an unaffected identical twin (D.I.) for comparative study. Both were assessed by comparing panoramic radiographs and lateral and frontal tracings of cephalometric radiographs obtained at 8.25 years of age. C.I. had multiple dental anomalies which included agenesis, ectopia, crown malformation, and root malformation. Root malformation, ectopia, and agenesis were restricted to the left dentition, whereas crown malformation was noted bilaterally. C.I. had a generalized craniofacial skeletal hypoplasia relative to D.I. in all three planes, growth defects were greater on the side of the tumor, and the mandible was affected more than the nasomaxillary complex.

[Production of gamma interferon and interleukin 2 in mononuclear spleen cells stimulated with concanavalin A]

Relationships between interleukine-2 and interferon production by mononuclear cells of mouse spleens stimulated with concanavalin A were studied.

Do pressure-demand breathing systems safeguard against inward leakage?

Rescue operations conducted in toxic atmospheres require respiratory protective equipment capable of providing a very high degree of protection. A slight positive pressure in the facepiece throughout the breathing cycle is used in the pressure-demand, compressed-air breathing apparatus to eliminate any inward leakage. In the present work an inward leakage test with sulphur hexafluoride (SF6) was used to measure facepiece penetration in a pressure-demand system at different work loads. During the test, inspiratory-flow pressure variations within the facepiece and heart rate were also measured. Tests were performed on a dummy head and on two subjects. In some tests a poor face seal was introduced by putting an open tubing with an inner diameter of 2 mm and outer diameter of 3 mm under the sealing edge of the mask. It was found that inward leakage was less than 0.0001% under all conditions as long as facepiece pressure was positive. When facepiece pressure fell below zero, which occurred at inhalation peak flows about 300 L/min, an inward leakage was detected. One subject achieved, at extreme work load, an inhalation peak flow around 450 L/min. These results show that pressure-demand systems should be tested with a breathing machine giving peak flows of at least 300 L/min to ascertain the capability of these systems to maintain positive pressure in the facepiece during hard rescue work.