Tracing biogeochemical subsidies from glacier runoff into Alaska's coastal marine food webs.

Nearly half of the freshwater discharge into the Gulf of Alaska originates from landscapes draining glacier runoff, but the influence of the influx of riverine organic matter on the trophodynamics of coastal marine food webs is not well understood. We quantified the ecological impact of riverine organic matter subsidies to glacier-marine habitats by developing a multi-trophic level Bayesian three-isotope mixing model. We utilized large gradients in stable (δ13 C, δ15 N, δ2 H) and radiogenic (Δ14 C) isotopes that trace riverine and marine organic matter sources as they are passed from lower to higher trophic levels in glacial-marine habitats. We also compared isotope ratios between glacial-marine and more oceanic habitats. Based on isotopic measurements of potential baseline sources, ambient water and tissues of marine consumers, estimates of the riverine organic matter source contribution to upper trophic-level species including fish and seabirds ranged from 12% to 44%. Variability in resource use among similar taxa corresponded to variation in species distribution and life histories. For example, riverine organic matter assimilation by the glacier-nesting seabirds Kittlitz's murrelet (Brachyramphus brevirostris) was greater than that of the forest-nesting marbled murrelet (B. marmoratus). The particulate and dissolved organic carbon in glacial runoff and near surface coastal waters was aged (12100-1500 years BP 14 C-age) but dissolved inorganic carbon and biota in coastal waters were young (530 years BP 14 C-age to modern). Thus terrestrial-derived subsidies in marine food webs were primarily composed of young organic matter sources released from glacier ecosystems and their surrounding watersheds. Stable isotope compositions also revealed a divergence in food web structure between glacial-marine and oceanic sites. This work demonstrates linkages between terrestrial and marine ecosystems, and facilitates a greater understanding of how climate-driven changes in freshwater runoff have the potential to alter food web dynamics within coastal marine ecosystems in Alaska.

Measurement of the positive muon lifetime and determination of the Fermi constant to part-per-million precision.

We report a measurement of the positive muon lifetime to a precision of 1.0 ppm; it is the most precise particle lifetime ever measured. The experiment used a time-structured, low-energy muon beam and a segmented plastic scintillator array to record more than 2×10(12) decays. Two different stopping target configurations were employed in independent data-taking periods. The combined results give τ(µ(+)) (MuLan)=2 196 980.3(2.2) ps, more than 15 times as precise as any previous experiment. The muon lifetime gives the most precise value for the Fermi constant: G(F) (MuLan)=1.166 378 8(7)×10(-5) GeV(-2) (0.6 ppm). It is also used to extract the µ(-)p singlet capture rate, which determines the proton's weak induced pseudoscalar coupling g(P).

Yield of clinically reportable genetic variants in unselected cerebral palsy by whole genome sequencing.

Cerebral palsy (CP) is the most common cause of childhood physical disability, with incidence between 1/500 and 1/700 births in the developed world. Despite increasing evidence for a major contribution of genetics to CP aetiology, genetic testing is currently not performed systematically. We assessed the diagnostic rate of genome sequencing (GS) in a clinically unselected cohort of 150 singleton CP patients, with CP confirmed at >4 years of age. Clinical grade GS was performed on the proband and variants were filtered, and classified according to American College of Medical Genetics and Genomics-Association for Molecular Pathology (ACMG-AMP) guidelines. Variants classified as pathogenic or likely pathogenic (P/LP) were further assessed for their contribution to CP. In total, 24.7% of individuals carried a P/LP variant(s) causing or increasing risk of CP, with 4.7% resolved by copy number variant analysis and 20% carrying single nucleotide or indel variants. A further 34.7% carried one or more rare, high impact variants of uncertain significance (VUS) in variation intolerant genes. Variants were identified in a heterogeneous group of genes, including genes associated with hereditary spastic paraplegia, clotting and thrombophilic disorders, small vessel disease, and other neurodevelopmental disorders. Approximately 1/2 of individuals were classified as likely to benefit from changed clinical management as a result of genetic findings. In addition, no significant association between genetic findings and clinical factors was detectable in this cohort, suggesting that systematic sequencing of CP will be required to avoid missed diagnoses.

Calciuria, oxaluria and phosphaturia after ingestion of glucose, xylitol and sorbitol in two population groups with different stone-risk profiles.

The effects of glucose, sorbitol and xylitol ingestion on calciuria, oxaluria and phosphaturia in healthy black and white males on a standardized diet were investigated. After ingestion, they collected urine hourly for 3 h. Glucose decreased phosphaturia in blacks. Sorbitol decreased phosphaturia in both groups and increased oxaluria in whites. Xylitol increased oxaluria in blacks. Decreases in phosphaturia are attributed to penetration by phosphate into cells leading to decreases in phosphatemia and the renal filtered load. We suggest that this mechanism is more sensitive in blacks. We speculate that the increase in oxaluria after sorbitol ingestion occurs via its conversion to glyoxylate and that this pathway may be blocked in blacks. For the increase in oxaluria after xylitol ingestion, it is hypothesized that ketohexokinase and aldolase may be more active in blacks. Our results demonstrate, for the first time, a urinary effect due to sorbitol ingestion and an ethnic dependency of these and other effects.

Targeted resequencing identifies genes with recurrent variation in cerebral palsy.

A growing body of evidence points to a considerable and heterogeneous genetic aetiology of cerebral palsy (CP). To identify recurrently variant CP genes, we designed a custom gene panel of 112 candidate genes. We tested 366 clinically unselected singleton cases with CP, including 271 cases not previously examined using next-generation sequencing technologies. Overall, 5.2% of the naïve cases (14/271) harboured a genetic variant of clinical significance in a known disease gene, with a further 4.8% of individuals (13/271) having a variant in a candidate gene classified as intolerant to variation. In the aggregate cohort of individuals from this study and our previous genomic investigations, six recurrently hit genes contributed at least 4% of disease burden to CP: COL4A1, TUBA1A, AGAP1, L1CAM, MAOB and KIF1A. Significance of Rare VAriants (SORVA) burden analysis identified four genes with a genome-wide significant burden of variants, AGAP1, ERLIN1, ZDHHC9 and PROC, of which we functionally assessed AGAP1 using a zebrafish model. Our investigations reinforce that CP is a heterogeneous neurodevelopmental disorder with known as well as novel genetic determinants.

Schwann cell precursors transplanted into the injured spinal cord multiply, integrate and are permissive for axon growth.

There is a strong current interest in the use of cell transplantation for the treatment of spinal cord injuries. We report here the novel and potentially useful properties of an early cell in the Schwann cell lineage, the Schwann cell precursor (SCP). The experiments reveal a striking difference between these cells and Schwann cells when transplanted into the CNS. Unlike Schwann cells, SCPs thrive in the CNS where they initially proliferate rapidly but then fall out of division, thus effectively filling up the large cystic cavities formed following crush injury, while avoiding tumor formation. By 8 weeks, SCPs had started to express S100beta protein, a marker that differentiates Schwann cells from SCPs and had formed an apparently stable, vascularized cell mass, which created a continuous cellular bridge across the cystic cavities. The formation of the surrounding glial scar was reduced by local spread of the transplanted cells into the surrounding CNS tissue, where the cells integrated intimately with astrocytes and attenuated the physical barrier they normally form. SCP transplantation also altered and reduced the expression of chondroitin sulfate proteoglycans around the injury site. Caudal to the SCP transplants there was a large increase in the number of axons, compared with that seen in nontransplanted control tissue, showing that the implants effectively support axonal growth or sprouting. SCPs have advantageous attributes for CNS repair, despite the fact that sticky tape removal and ladder crossing tests at 8 weeks did not reveal significant functional improvements when compared with control animals.

Effects of direct transplantation of multipotent mesenchymal stromal/stem cells into the demyelinated spinal cord.

The adult bone marrow contains a population of multipotent mesenchymal stromal cells (MSCs), defined by plastic adherence, expression of stromal cell surface markers, and differentiation into mesenchymal lineages. There has been much interest in the possible therapeutic use of MSCs in the treatment of demyelinating diseases of the central nervous system. One therapeutic possibility is that these cells may be able to remyelinate when directly injected into the demyelinated spinal cord. Here we examine the effects of direct transplantation of green fluorescent protein (GFP)-labeled MSCs into a model of focal spinal cord demyelination induced by ethidium bromide. We demonstrate that direct intralesional injection of undifferentiated MSCs does not lead to remyelination. Furthermore, we report that transplanted MSCs migrate into areas of normal tissue, deposit collagen, and are associated with axonal damage. These findings support the need for further experimental evaluation of the safety and efficacy of direct parenchymal injection of MSCs into demyelinated lesions and highlight an important issue regarding potential clinical consequences of culture heterogeneity of MSCs between centers.

Easy-to-implement Bayesian methods for dose-escalation studies in healthy volunteers.

In phase I clinical trials, experimental drugs are administered to healthy volunteers in order to establish their safety and to explore the relationship between the dose taken and the concentration found in plasma. Each volunteer receives a series of increasing single doses. In this paper a Bayesian decision procedure is developed for choosing the doses to give in the next round of the study, taking into account both prior information and the responses observed so far. The procedure seeks the optimal doses for learning about the dose-concentration relationship, subject to a constraint which reduces the risk of administering dangerously high doses. Individual volunteers receive more than one dose, and the pharmacokinetic responses observed are, after logarithmic transformation, treated as approximately normally distributed. Thus data analysis can be achieved by fitting linear mixed models. By expressing prior information as 'pseudo-data', and by maximizing over posterior distributions rather than taking expectations, a procedure which can be implemented using standard mixed model software is derived. Comparisons are made with existing approaches to the conduct of these studies, and the new method is illustrated using real and simulated data.To whom correspondence should be addressed.

Experimental determination of multiple thermodynamic and kinetic risk factors for nephrolithiasis in the urine of healthy controls and calcium oxalate stone formers: does a universal discriminator exist?

Nephrolithiasis is thought to be governed by urinary thermodynamic and kinetic risk factors. However, identification of one or more of these factors which consistently and unambiguously differentiates between healthy subjects (N) and calcium oxalate (CaOx) renal stone patients (SF) remains elusive. The present study addresses this challenge. 24 h urines were collected from 15 N and 10 SF. Urine compositions were used to compute thermodynamic risk indices including urinary ratios, quotients and supersaturation (SS) values, while CaOx metastable limits (MSL) were determined experimentally. Crystallisation kinetics was determined by measuring rates of particle formation (number, volume, size) using a Coulter counter multisizer (CC) and a Coulter flow cytometer (FC). Particle shapes were qualitatively differentiated by FC and were viewed directly by scanning electron microscopy. Several urinary composition ratios and risk quotients were significantly different between the groups. However, there were no significant differences between CaOx MSL or SS values. Using transformed FC data, the rate of CaOx crystallisation in SF was significantly greater than in N. This was not supported by CC measurements. There were no significant differences between the groups with respect to particle size or CaOx crystal growth rates. Single and aggregated CaOx dihydrate crystals were observed in both groups with equal frequency and there were no differences in the kinetic properties of these deposits. A few CaOx monohydrate crystals were observed in SF. Although several risk factors were found to be significantly different between the groups, none of them were consistently robust when compared to other cognate factors. Arguments were readily invoked which demonstrated inter-factor inconsistencies and conflicts. We suspect that a unique discriminatory factor, such as any of those which we investigated in the present study, may not exist.

Correlation of an osteoclast antigen and ruffled border on giant cells formed in response to resorbable substrates.

The osteoclast is the specialized multinucleated cell primarily responsible for the degradation of the organic and inorganic components of bone matrix. The functional and developmental relationship between osteoclasts and foreign body giant cells is unclear. The osteoclast plasma membrane ruffled border juxtaposed to the bone surface is a unique morphologic characteristic of active osteoclasts. In the studies reported here giant cell formation was induced in response to a variety of materials implanted onto the richly vascularized chick chorioallantoic membrane. Light and electron microscopic techniques were used to examine the morphologic characteristics of the giant cells. In addition, immunohistochemical methods were used to demonstrate the appearance of a 150 kD cell surface antigen on chicken osteoclasts recognized by monoclonal antibody 121F. Giant cells that formed in response to mineralized bone particles exhibited ruffled borders and stained positively with the 121F antibody. Many giant cells that formed in response to hydroxyapatite possessed ruffled borders similar to but not as extensive as those observed on giant cells formed on bone. Immunohistochemical localization of the 121F antigen on these cells suggested that the antigen was present, but staining intensity was reduced compared to that of bone-associated giant cells. The formation of mineral matrix complexes by the adsorption to hydroxyapatite of bone extract or osteocalcin enhanced ruffled borders and the presence of the 121F antigen on elicited giant cells. In contrast, giant cells that formed on non-resorbable materials, such as Sepharose beads, mica, and methacrylate, lacked ruffled borders and were negative for the 121F antigen. It appears that expression of the 121F osteoclast antigen correlates with the appearance and extent of ruffled membranes on giant cells. Furthermore, it appears that giant cell ruffled membrane development and the presence of the 121F osteoclast antigen are related to giant cell formation in response to resorbable materials that are subject to extracellular dissolution. Expression of this antigen may be indicative of the developmental and/or functional state of giant cells (osteoclasts) that form on resorbable substrates. In addition, components of the bone matrix, including osteocalcin, in association with bone mineral, lead to elevated levels of this osteoclast antigen.

Osteoclast-specific monoclonal antibodies coupled to magnetic beads provide a rapid and efficient method of purifying avian osteoclasts.

Osteoclasts are the major cell type responsible for normal and pathologic bone resorption. Obtaining highly purified populations of these multinucleated cells has been problematic, although such populations would greatly facilitate investigations of osteoclast regulation and activity. A new immunomagnetic protocol has been devised to surmount these difficulties, employing avian osteoclast-directed monoclonal antibodies (designated 121F, 35L, and 75B) surface coupled to uniformly small, magnetic polystyrene beads covalently conjugated with sheep antimouse IgG. Presentation of these antiosteoclast antibody-coated beads to mixed cell preparations derived from marrow-depleted, collagenase- and/or trypsin-treated chick tibiae and wing bones, followed by magnetic separation and washing, results in efficient and selective binding of osteoclasts to the immunomagnetic beads within minutes. The specific nature of this bead-cell interaction is further demonstrated by the progressive decline in antiosteoclast antibody-coated bead binding to osteoclasts by uncoated beads or beads coated with an irrelevant antibody. Under optimal conditions, these isolations typically yield more than a 100-fold enrichment and greater than a 90% purification of osteoclasts from subpopulations of either predominantly nonviable or viable osteoclasts. Although scanning electron microscopy reveals that immunomagnetically purified and cultured osteoclasts internalize large numbers of the antibody-coated beads, such cells appear unimpaired in their ability to attach to tissue culture plastic or devitalized cortical bone slices and to produce resorption pits characteristic for osteoclasts. Additional studies to ascertain the most effective method for removal (desorption) of antibody-coated beads from magnetically isolated osteoclasts demonstrate that moderate physical agitation is at present the most effective protocol to dislodge antibody-coated beads from the cell surface while maintaining osteoclast viability and function. This immunomagnetic technique therefore provides a gentle method for the isolation of highly purified populations of osteoclasts from heterogeneous bone cell populations in a rapid, efficient, and selective manner.

The effect of tartrate on bone cell acid phosphatase activity: a quantitative cytochemical study.

Tartrate-resistant acid phosphatase activity (TRAPase) is widely used as a cytochemical marker to distinguish osteoclasts from macrophages and other related cell types. The degree of tartrate resistance, however, may depend on which reaction methods, tissues, or species are used. To investigate this further, we have measured the amount of cytochemical reaction product by microdensitometry. We compared osteoclast acid phosphatase (APase) activity in fresh frozen sections of neonatal rat calvaria using two different reaction methods; one is commonly employed for qualitative histochemistry and includes alpha naphthyl phosphate as substrate, simultaneous coupling to the chromagen Fast Garnet, and a 30-minute reaction time (method A). The other may be used to measure enzyme reaction rates in cells in situ and employs conditions suitable for initial velocity kinetics, namely naphthol-ASBI phosphate as substrate, post coupling to Fast Garnet, and a 2-minute reaction time. Although enzyme reaction rates differed greatly between the two methods, significant inhibition of APase activity by tartrate was observed in calvarial osteoclasts (69% and 59% with methods A and B, respectively), osteoblasts, and spleen macrophages. Using method B, mouse calvarial osteoclasts had similar APase activity to that seen in the rat. Tartrate produced little inhibition in these mouse cells, in contrast to the observations made with rat tissue, but murine spleen macrophages were significantly tartrate sensitive (40% inhibition with tartrate). On this basis, conclusions regarding the cell specificity of TRAPase should be treated cautiously.

Isolation of avian osteoclasts: improved techniques to preferentially purify viable cells.

Among the many different methods that have been used to obtain and study isolated osteoclasts from a variety of species, the egg-laying hen maintained on a low-calcium diet has proven to be one of the richest sources of relatively large numbers of osteoclasts. However, recent reports and our own observations indicate that only a very small proportion of the osteoclasts harvested by such methods are viable. The difficulty in obtaining large numbers of viable osteoclasts has restricted studies of osteoclast function and regulation, and so new isolation methods were sought. This report describes an osteoclast isolation procedure designed to substantially enrich for large numbers of viable authentic osteoclasts. Size and cell density differences between osteoclasts and contaminating mononuclear cells have been exploited in developing the methods for osteoclast enrichment. Sequential nonenzymatic and enzymatic procedures, followed by cell density separations, have yielded three populations of osteoclasts derived from chick hatchlings maintained on a low-calcium diet. A corresponding decrease in bone-associated osteoclasts during the sequential isolation scheme has been monitored using an osteoclast-directed monoclonal antibody, 121F. The first two populations contain 40% osteoclasts, which are predominantly (greater than 99%) nonviable, but the third population contains 8-fold more viable osteoclasts, effectively increasing the proportion of viable osteoclasts more than 25-fold in comparison with the first two populations. The osteoclast-like nature of the isolated viable population 3 cells was established by demonstrating ruffled border formation, possession of the 121F monoclonal antibody-reactive osteoclast antigen, bone particle resorption activity, and resorption pit formation on cortical bone slices revealed by transmission and scanning electron microscopy.

Location of osteoclast precursors in fetal rat calvaria cultured on collagen gels.

Although osteoclasts are derived from hematopoietic cells, the exact identity of their precursors and the mechanism for their recruitment onto bone surfaces remain unclear. We wished to study their differentiation in the fetal rat calvaria and to locate its source of osteoclast precursor cells. Osteoclasts were detected by neutral red staining or cytochemical reaction for acid phosphatase of intact bone (cell number and area measured by computerized image analysis) or in cryostat sections of bone (enzyme activity measured by quantitative cytochemistry). Histology of semithin sections of fixed bones was also examined. The 19 day calvariae contained few mature osteoclasts. After 48 h culture on gels of type 1 collagen (1.5 mg/ml) supplemented with 5 mM calcium beta-glycerophosphate, 10 mM proline, and 2 micrograms/ml ascorbic acid, numerous large osteoclasts were seen on their endocranial surfaces. In contrast, cell morphology and enzyme activity deteriorated in bones cultured in liquid medium. The cells that formed in vitro rapidly responded to calcitonin by contraction. Stripping of endocranial membranes from the calvariae prevented osteoclast formation in culture, but these cells were seen when "stripped" bones had been cocultured with their membranes for 48 h or with intact 16 day calvariae (well before the onset of osteogenesis). Few osteoclasts were found when an 0.22 micron filter was inserted between the stripped calvaria and the endocranial membranes. We conclude that the endocranial membranes, which contain the meningeal blood vessels, are a major source of osteoclast precursors and that these cells are present in calvarial tissue even before the onset of osteogenesis.

Detection of canine distemper virus in bone cells in the metaphyses of distemper-infected dogs.

In the light of recent evidence implicating canine distemper virus (CDV) as a possible etiologic agent in Paget's disease of bone, we thought that it would be of interest to examine distemper-infected bone in the natural host. Samples from the long bones, spleen, and bladder of four distemper-infected and three uninfected dogs were examined for the presence of CDV nucleocapsid and phosphoprotein genes and the measles virus (MV) nucleocapsid gene using the technique of in situ hybridization with radioactively labeled riboprobes. Two of the four distemper-infected dogs showed strongly positive hybridization with both of the CDV probes. The signal was present in marrow cells, in osteoblasts, in osteocytes, and particularly in osteoclasts. No hybridization was seen over the cartilage cells of the growth plate, and there was a clear line of demarcation at the point of invasion of osteoclasts and vascularization. The spleen and bladder samples from infected dogs also showed positive hybridization. There was no hybridization with the MV probe in any of the distemper-infected tissue. Samples from the uninfected dogs showed no evidence of hybridization with either the CDV or MV probes. These results show that CDV can infect bone cells of the natural host and provide further support for the theory that CDV may play a role in human Paget's disease of bone.

Osteoclast 121F antigen expression during osteoblast conditioned medium induction of osteoclast-like cells in vitro: relationship to calcitonin responsiveness, tartrate resistant acid phosphatase levels, and bone resorptive activity.

Osteoclast differentiation from hematopoietic precursors into multinucleated cells uniquely capable of removing the organic and inorganic components of bone matrix occurs in multistep process, during which osteoclasts acquire the specialized characteristics necessary for bone resorptive activity and physiological regulation. Among those traits is a novel plasma membrane glycoprotein, reactive with the anti-osteoclast monoclonal antibody 121F, which is expressed during the course of osteoclast differentiation, shares structural and functional homologies with Mn2+/Fe2+ superoxide dismutase, and has been hypothesized to protect the osteoclast from the damaging effects of superoxide radicals generated during active bone resorption. We have reported previously that the expression of this membrane antigen is induced on multinucleated giant cells when the prefusion marrow mononuclear cells are cultured in conditioned medium from avian calvaria. The studies reported here were designed to investigate the relationship between expression of the 121F antibody-reactive osteoclast membrane antigen and tartrate resistant acid phosphatase levels, bone resorptive activity, calcitonin responsiveness, and ultrastructural features of avian bone marrow-derived multinucleated giant cells formed either in the presence or absence of diffusible osteoblast secreted factors. Parallel analyses of in vivo formed osteoclasts isolated from the same animals were performed for direct comparisons. In this report we demonstrate: (1) that the 121F monoclonal antibody-reactive osteoclast membrane antigen is stably induced in giant cells by soluble osteoblast-derived factors in a species nonrestricted but concentration- and temporal-dependent manner; (2) that osteoblast-mediated antigen induction is reflected in both increased numbers of cells and elevated expression of individual cells that are reactive with the 121F antibody, as determined by ELISA and histomorphometry; (3) that osteoblast conditioned medium, in addition to inducing this antigen in bone marrow cells, also elevates other defining osteoclast characteristics in these avian giant cells including their TRAP activity, cell retraction from the bone surface in response to calcitonin, bone resorptive function, and expression of a series of additional osteoclast antigenic markers; and (4) that secreted osteoblast products alone do not raise the levels of these traits for in vitro formed marrow giant cells to the extent associated with in vivo formed osteoclasts. Therefore, osteoblast soluble factors alone appear unable to promote the full differentiation of bone marrow cells in vitro into mature bone-resorbing osteoclasts.(ABSTRACT TRUNCATED AT 400 WORDS)

Comparison of a medium supplement--'Nu-Serum'--and foetal calf serum in RPMI 1640 used for the murine allogeneic mixed lymphocyte reaction.

A commercially available medium supplement, Nu-Serum, was compared with foetal calf serum for its ability to support the murine allogeneic mixed lymphocyte reaction. Nu-Serum supported proliferation whilst at the same time producing significantly lower counts in unstimulated cultures. There was considerably less batch-to-batch variation with Nu-Serum than with foetal calf serum, which obviated the need for pretesting in order to find a suitable batch.

Correlation of endogenous somatostatin, gastric inhibitory polypeptide, glucagon and insulin with gastric function in the conscious calf.

Levels of endogenous somatostatin, gastric inhibitory polypeptide (GIP), glucagon and insulin were measured during gastric (abomasal) emptying in the conscious calf. Isotonic NaHCO3 infused into the duodenum increased rates of emptying of a saline test meal and of gastric acid secretion, but had no effect on basal levels of blood glucose, somatostatin, GIP, insulin or glucagon. By contrast, intraduodenal infusion of 60 mM-HCl caused complete inhibition of gastric emptying, reduction of acid secretion, and an immediate increase in plasma somatostatin from 121.3 +/- 9.4 (S.E.M.) to 286.3 +/- 16.3 pg/ml (P less 0.01) but levels of GIP, insulin, glucagon and glucose were unaltered. Intravenous injection of somatostatin (0.5 microgram/kg) suppressed the antral electromyographic recording and gastri efflux so long as plasma somatostatin levels remained above approx. 200pg/ml. This suggest that somatostatin can be released by intraduodenal acidification and that it inhibits gastric function by an endocrine effect. Since somatostatin retards gastric emptying it may therefore have an indirect role in nutrient homeostasis by limiting discharge of gastric chyme to the duodenum.

S-100 staining in the diagnosis of eosinophilic granuloma of lung.

The authors used immunohistochemical staining for S-100 protein to search for Langerhans cells in 7 cases of pulmonary eosinophilic granuloma (EGL) and in 18 cases of other pulmonary processes (including reactive eosinophilic pleuritis, chronic interstitial pneumonias, eosinophilic pneumonia, and nonspecific scars), which can produce diagnostic confusion with EGL. Qualitatively, Langerhans cells were found in almost every disease. However, cases of active or resolving EGL showed greater than 75 such cells/10 high-power fields (hpf), often appearing as densely packed aggregates (a virtually diagnostic feature), while all other conditions, including completely scarred EGL, showed fewer than 35 Langerhans cells/10 hpf, and the cells were scattered through the parenchyma. The authors conclude the following: (1) Langerhans cells participate in many types of inflammatory process in the lung, and hence the mere presence of Langerhans cells is not diagnostic of EGL; (2) S-100 staining with quantitation of Langerhans cells is a useful adjunct in the diagnosis of active and resolving EGL.

Radioimmune localization of occult carcinoma.

Patients with a rising serum carcinoembryonic antigen level and no clinical or roentgenographic evidence of recurrent or metastatic cancer present a treatment dilemma. Eleven such patients, 10 with a previously treated colorectal carcinoma and 1 with a previously treated breast carcinoma, received an injection of the anticarcinoembryonic antigen monoclonal antibody ZCE-025 labeled with the radioisotope indium 111. Nuclear scintigraphy was performed on days 3 and 5 through 7 to detect potential sites of tumor recurrence. The monoclonal antibody scan accurately predicted the presence or absence of occult malignancy in 7 (64%) patients. Second-look laparotomy confirmed the monoclonal antibody scan results in the patients with colorectal cancer, and magnetic resonance imaging confirmed metastatic breast cancer. This study demonstrates that In-ZCE-025 can localize occult carcinoma and may assist the surgeon in facilitating the operative exploration. In-ZCE-025 assisted in the initiation of adjuvant therapy for the patient with breast cancer.