Provider Perceptions of a Novel Inpatient Co-Rounding Model Integrating Medical Oncology, Neuro-Oncology, and Radiation Oncology for the Care of Patients with Advanced Cancer

PURPOSE/OBJECTIVE(S)

Patients (pts) with advanced cancer require interdisciplinary care. Although tumor boards are well-established in the outpatient setting, few studies have evaluated interventions for improving consultative care coordination for hospitalized pts with cancer. The purpose of this study was to evaluate a novel inpatient co-rounding model of care in which medical-, neuro-, and radiation-oncology consult teams rounded jointly, with the hypothesis that primary referring team perception of the alignment of the recommendations from these consult services would improve post-implementation.

MATERIALS/METHODS

An inpatient co-rounding model was implemented in September 2021 for hospitalized pts with solid malignancies at a tertiary medical center. Attending physicians, nurse practitioners, fellows, and residents from oncologic consulting services met virtually twice weekly to discuss pt care. Providers from the two most common primary services for pts with cancer at this hospital (hospital medicine and neurosurgery) were surveyed via institutional email listservs. The survey included Likert-type questions about the quality of inpatient consultation and the alignment of recommendations across three consulting oncological specialty services. The pre-intervention survey was distributed prior to model implementation, and the post-intervention survey was distributed 9 months later. Wilcoxon rank-sum tests were used to compare responses from the pre-and post-intervention surveys.

RESULTS

At each session, a median of 6 providers attended (range, 4-8 providers), and a median of 6 pts were discussed (range, 4-8 pts). Among 331 providers surveyed, 119 completed the pre-intervention survey (36% response rate), and 34 completed the post-intervention survey (10% response rate). Respondents were 81 (53%) internal medicine attending physicians/hospitalists, 55 (36%) internal medicine resident physicians, 6 (4%) neurosurgery advanced practice providers, 6 (4%) neurosurgery attending physicians, and 5 (3%) neurosurgery resident physicians. When asked to rate agreement with the statement that consultant recommendations from medical-, neuro-, and radiation-oncology were aligned, respondents were significantly more likely to perceive alignment 9 months post-implementation (67% strongly agree) compared to pre-implementation (23% strongly agree, p = 0.0001). There was high satisfaction with the quality of medical-, neuro-, and radiation-oncology consultations at both time points, with no statistical difference pre- vs. post-implementation of the co-rounding model.

CONCLUSION

A novel inpatient co-rounding model of care was successfully launched between medical-, neuro-, and radiation-oncology. Primary teams perceived greater alignment in recommendations between these consulting services after project implementation. Future directions include evaluating the impact of this co-rounding model on patient outcomes.

Adenomas with high-grade dysplasia and early adenocarcinoma are more likely to be sessile in the proximal colon

AIM

Size and the sessile morphology of an adenoma may explain why colonoscopy is less effective in preventing proximal colonic cancer than distal cancers. We wanted to determine if advanced polypoid neoplasms (APNs, i.e. adenoma with high-grade dysplasia or early adenocarcinoma) are more likely to be sessile and/or smaller in the proximal colon.

METHOD

We searched our institution's pathology database from 2004 to 2012 and identified patients with APNs. Polyps were categorized by size, morphology and location in the colon. Average polyp size and morphology were determined for each location.

RESULTS

During the study period, 564 patients with APNs were identified. Of these, adenocarcinoma was noted in 21.6% and high-grade dysplasia in 78.4%. The average patient age was 64.4 years and 54.9% were men. The proportion of APNs that were ≤ 5 mm was 1.7%, ≤ 10 mm 19.3% and ≤ 15 mm 39%. APNs in the proximal colon were larger than those in the distal colon, but the difference was not statistically significant (27 vs 24 mm; P = 0.06). Eighty-three per cent of APNs in the proximal colon were sessile vs 57% in the distal colon (P = 0.001). APNs in the proximal colon were almost four times more likely to be sessile than in the distal colon (OR = 3.7). A similar association was noted for polyps ≤ 20 mm or polyps with high-grade dysplasia.

CONCLUSION

APNs in the proximal colon were almost four-times more likely to be sessile than those in the distal colon. No difference in the size of polyps was noted.

Milk-induced wheezing in children with asthma

BACKGROUND

Food allergy has been gaining increasing attention, mostly as causing gastrointestinal and cutaneous reactions. Its role in asthma seems to be under-recognised.

OBJECTIVES

This study's aim is to explore the frequency of involvement of a common food, namely cow's milk, in childhood asthma.

METHODS

32 children (5 months to 11 years; median 24 months; mean 34 months) with asthma and a suspected history of cow's milk allergy were studied. They underwent skin prick testing (SPT) and specific IgE (sIgE) testing to whole cow's milk (WCM), casein, α-lactalbumin, and β-lactoglobulin, followed by single-blind oral milk challenge.

RESULTS

Reactions to milk challenge occurred in 12 (37.5%) including wheezing in 5 (41.7%, or 15.6% of the whole group). Children who developed wheezing at the time of challenge were younger than those who had negative challenge (23.0 months vs. 34.8 months). Challenge was positive in 33.3% of subjects who had a positive SPT, and SPT was positive in 50% of challenge-positive subjects. Regarding sIgE, challenge was positive in 26.7% of sIgE-positive subjects, and sIgE was positive in 33.3% of challenge positive subjects. Skin or serum testing with individual protein fractions did not seem to add significant advantage over testing with WCM alone.

CONCLUSION

This study shows that cow's milk can cause wheezing in children with asthma. Although SPT seemed to be more reliable than sIgE testing, both had suboptimal reliability. It is worth considering possible milk allergy in children with asthma, particularly when poorly controlled in spite of proper routine management.

GB toxicity reassessed using newer techniques for estimation of human toxicity from animal inhalation toxicity data: New method for estimating acute human toxicity (GB)

Estimated human inhalation toxicity values for Sarin (GB) were calculated using a new two independent (concentration, exposure time), one dependent (toxic response), non-linear dose response (toxicity) model combined with re-evaluated allometric equations relating to animal and human respiration. Historical animal studies of GB toxicity containing both exposure and fractional animal response data were used to test the new process. The final data set contained 6621 animals, 762 groups, 37 studies and 7 species. The toxicity of GB for each species was empirically related to exposure concentration (C; mg m(-3)) and exposure time (T; min) through the surface function Y = b0 + b1 Log10C + b2 Log10T or Y = b0 + b2 Log10C(n)T where Y is the Normit, b0, b1 and b2 are constants and n is the 'toxic load exponent' (Normit is PROBIT - 5). Between exposure times of 0.17 and 30 min, the average value for n in seven species was 1.35 +/- 0.15. The near parallel toxic load equations for each species and the linear relationship between minute volume/body weight ratio and the inhalation toxicity (LCt50) for GB were used to create a pseudo-human data set and then an exposure time/toxicity surface for the human. The calculated n for the human was 1.40. The pseudo-human data had much more variability at low exposure times. Raising the lower exposure limit to 1 min, did not change the LCt50 but did result in lower variability. Raising the lower value to 2 min was counterproductive. Based on the toxic load model for 1-30 min exposures, the human GB toxicities (LCt01, LCt05, LCt50 and LCt95) for 70 kg humans breathing 15 l min(-1) were estimated to be 11, 16, 36 and 83; 18, 25, 57 and 132 and 24, 34, 79 and 182 mg x min m(-3) for 2, 10 and 30 min exposures, respectively. These values are recommended for general use for the total human population. The empirical relationships employed in the calculations may not be valid for exposure times >30 min.

Allometric respiration/body mass data for animals to be used for estimates of inhalation toxicity to young adult humans

The relationship between body weight (BW) and respiratory minute volume (V(m)) was reviewed by collecting a database from the literature. The data were separated into anaesthetized and non-anaesthetized groups. Only young adult terrestrial mammals were included in the final data set. This database is the largest to be reported to date, is the first to separate the anaesthetized and non-anaesthetized groups and is matched to the target population of young, fit adult humans. The data set of non-anaesthetized animals contained 142 studies representing 2616 animals and 18 species from mice at 12 g body weight to horses and a giraffe at ca. 500 kg body weight. Analysis of the data indicated a power law (allometric) relationship between the minute volume and body weight. The resulting allometric equations for the empirical relationship between minute volume and body weight are: log(10)V()(m)= -0.302 + 0.809 log(10)BW and V(m) = 0.499 BW(0.809)where V(m) is the minute volume (l min(-1)) and BW is the body weight (kg). From these equations, a minute volume of 15.5 lmin(-1)was obtained for a 70 kg human in the same physiological and/or emotional state as the animals. The results of the analyses were compared to other empirical studies in the literature, the more recent of which also indicated a scaling factor of 0.8. The relationship between minute volume and body weight is recommended for use in estimating the inhalation toxicity to young adult humans (military personnel), because this is the first study to use a large database focused exclusively upon non-anaesthetized young adult terrestrial mammals.

NF-kappaB activation is required for human endothelial survival during exposure to tumor necrosis factor-alpha but not to interleukin-1beta or lipopolysaccharide

In the presence of a protein synthesis inhibitor, cycloheximide, tumor necrosis factor-alpha (TNF-alpha), interleukin 1-beta (IL-1beta), or lipopolysaccharide (LPS) induces human umbilical vein endothelial cells (HUVECs) to undergo apoptosis, suggesting that constitutive or inducible cytoprotective pathways are required for cell survival. We studied the correlation between nuclear factor-kappaB (NF-kappaB) activation and cell death induced by TNF-alpha, IL-1beta, or LPS. Adenovirus-mediated overexpression of a dominant-negative IkappaBalpha (inhibitor of kappaB) mutant blocked NF-kappaB activation by gel shift assay and blocked induction of vascular cell adhesion molecule-1 protein by TNF-alpha, IL-1beta, and LPS, a NF-kappaB-dependent response. In cells overexpressing the IkappaBalpha mutant, TNF-alpha induced cell death, whereas IL-1beta or LPS did not. We conclude that cell survival following TNF-alpha stimulation is NF-kappaB-dependent but that a constitutive or inducible NF-kappaB-independent pathway(s) protects IL-1beta- or LPS-treated HUVECs from cell death.

An impact-effect mathematical model incorporating the influence of exposures to fluctuating concentrations in a dispersing plume of pollutant in the atmosphere

The statistical properties of the impact or toxic load (pollutant concentration raised to an exponent and multiplied by exposure duration), obtained from fluctuating concentrations in a plume dispersing in the atmosphere, are investigated both analytically and experimentally. A general expression for the kth order moment of the impact is derived in terms of the k-time point joint moment of the nth power of the fluctuating plume concentration field. Special cases of this general relationship are treated explicitly: (i) a simple model for the ensemble-mean impact (or equivalently, the ensemble-mean impact ratio) is derived on the basic hypothesis that the higher moments of concentration can be adequately modelled using an exponential probability density function (PDF), and this hypothesis is shown to give results that agree remarkably well with an extensive new set of concentration fluctuation measurements; and (ii) a model for the integral time scale of the process obtained by raising the concentration to the nth power is formulated using Gifford's meandering plume model, and the latter is subsequently used to derive a simple expression for estimating the impact variance for all exposure times, given the mean and mean-square concentrations and the plume concentration integral time scale only. The results of this model for impact variance are favorably compared with some data from full-scale field experiments. The impact PDF is found to be reasonably well-characterized by a clipped-normal PDF for exposure times, t(e), of practical interest (e.g., t(e) approximately >5 s). The implications of these results, for determining the fraction of an exposed population that will experience a specified level of effect from a random impact arising from exposure to a fluctuating plume of pollutant, are discussed briefly.

Quantitation of human haptoglobin: comparative ELISA studies using adsorption and capture methods

Three ELISA methods for the quantitation of haptoglobin (Hp) in plasma and albumin are described: a polystyrene direct adsorption method and capture methods with antibody and hemoglobin. Hp aggregates generated by 60 degrees C heating showed as much as a hundred-fold higher response by polystyrene adsorption compared to the two capture methods, while unheated Hp showed comparable responses by the three methods.

Lipopolysaccharide induces the antiapoptotic molecules, A1 and A20, in microvascular endothelial cells

The effect of lipopolysaccharide (LPS) on endothelial cells is a key component of the inflammatory response seen in Gram-negative sepsis. LPS does not cause death of cultured human endothelial cells. However, when the expression of new proteins is inhibited by cycloheximide, microvascular endothelial cells in culture undergo apoptosis. This finding suggests that LPS induces apoptotic and antiapoptotic pathways, with the antiapoptotic response being dependent on the synthesis of new proteins. Concurrent activation of apoptotic and antiapoptotic pathways has previously been documented for tumor necrosis factor (TNF). In the case of TNF, the antiapoptotic signal has been attributed to at least two cytoprotective proteins: the Bcl-2 homologue, A1, and the zinc-finger protein, A20. In this study, we demonstrate that both these molecules are induced in microvascular endothelial cells by LPS. Enforced overexpression of either A1 or A20 inhibits LPS and cycloheximide-initiated apoptosis. Induction of A1 and A20 does not require synthesis of intermediary proteins, but is dependent on the presence of soluble CD14. In addition, we show that inhibition of signaling by the transcription factor, NF-kappaB, blocks accumulation of A1 and A20 mRNA. Taken together, our findings suggest that LPS directly induces expression of the cytoprotective proteins, A1 and A20, via a CD14-dependent pathway requiring activation of NF-kappaB.

Nitric oxide inhibits lipopolysaccharide-induced apoptosis in pulmonary artery endothelial cells

Our group recently reported that cultured sheep pulmonary artery endothelial cells (SPAECs) became resistant to lipopolysaccharide (LPS)-induced apoptosis several days after constitutive synthesis of nitric oxide (NO) after adenoviral (Ad) transfer of inducible NO synthase (iNOS) or exposure to the NO donor S-nitroso-N-acetylpenicillamine (SNAP) (E. Tzeng, Y.-M. Kim, B. R. Pitt, A. Lizonova, I. Kovesdi, and T. R. Billiar. Surgery 122: 255-263, 1997). In the present study, we confirmed this observation by establishing stable transfectants after retroviral gene transfer [replication-deficient retrovirus (DFG)] of human iNOS (DFG-iNOS) SPAECs and then used all three approaches (Ad, DFG, and SNAP) to determine underlying mechanisms of this phenomenon. Continuous endogenous production of NO in itself did not cause apoptosis as assessed by phase-contrast microscopy, nuclear morphology, and internucleosomal DNA fragmentation. Prolonged (72-96 h) synthesis of NO, however, after DFG- or replication-deficient adenovirus (Ad. CMV)-iNOS or SNAP (100 microM, 96 h) inhibited LPS-induced apoptosis. The kinetics of such protection suggested that NO may be inducing other gene products. Ad-mediated transfer of manganese superoxide dismutase (MnSOD) decreased the sensitivity of wild-type SPAECs to LPS-induced apoptosis. MnSOD, however, was not induced in an NG-monomethyl-L-arginine (L-NMMA)-sensitive time-dependent fashion after Ad.CMV-iNOS. Other inducible genes that may be affected by NO and that may protect against potential oxidant-mediated LPS-induced apoptosis including 70-kDa heat shock protein, heme oxygenase-1, metallothionein, and Bcl-2 also were not elevated in an L-NMMA-sensitive, time-dependent fashion. Although the candidate gene product underlying NO-induced protection remains unclear, we did note that prolonged synthesis of NO inhibited LPS-induced activation of an interleukin-1beta-converting enzyme-like cysteine protease (cysteine protease protein-32-like) in a dithiothreitol-sensitive fashion, suggesting that S-nitrosylation of an important downstream target of convergence of apoptotic signals may contribute to the sensitivity of SPAECs to LPS.

Lipopolysaccharide-induced NF-kappaB activation in human endothelial cells involves degradation of IkappaBalpha but not IkappaBbeta

We studied the signal transduction pathways involved in NF-kappaB activation and the induction of the cytoprotective A20 gene by lipopolysaccharide (LPS) in human umbilical vein endothelial cells (HUVEC). LPS induced human A20 mRNA expression with a maximum level 2 h after stimulation. The proteasome inhibitor N-acetyl-leucinyl-leucinyl-norleucinal-H (ALLN) and the tyrosine kinase inhibitor herbimycin A (HMA) blocked A20 mRNA expression and partially inhibited NF-kappaB DNA-binding activity induced by LPS treatment. LPS induced IkappaBalpha degradation at 30-60 min after treatment, but did not induce IkappaBbeta degradation up to 120 min. In contrast, TNF-alpha rapidly induced IkappaBalpha degradation within 5 min and IkappaBbeta degradation within 15 min. Cycloheximide did not prevent LPS-induced IkappaBalpha degradation, indicating that newly synthesized proteins induced by LPS were not involved in LPS-stimulated IkappaBalpha degradation. LPS-induced IkappaBalpha degradation was inhibited by ALLN, confirming that ALLN inhibits NF-kappaB activation by preventing IkappaBalpha degradation. Of note, HMA also inhibited LPS-induced IkappaBalpha degradation. However, tyrosine phosphorylation of IkappaBalpha itself was not elicited by LPS stimulation, suggesting that tyrosine phosphorylation of a protein(s) upstream of IkappaBalpha is required for subsequent degradation. We conclude that in HUVEC, LPS induces NF-kappaB-dependent genes through degradation of IkappaBalpha, not IkappaBbeta, and propose that this degradation is induced in part by HMA-sensitive kinase(s) upstream of IkappaBalpha.

A1 is a constitutive and inducible Bcl-2 homologue in mature human neutrophils

During the process of terminal differentiation toward mature neutrophils, the anti-apoptotic proteins Bcl-2 and Bcl-x become down-regulated and eventually cease to be expressed, whereas the death-promoting Bcl-2 homologue, Bax, persists. Thus, the disappearance of anti-apoptotic homologues was thought to account for the early demise of mature neutrophils. However, although the survival of mature human neutrophils can be prolonged by a variety of factors, no anti-apoptotic Bcl-2 homologues have previously been identified. Human A1 is a Bcl-2 homologue previously shown to be present in endothelial cells and to convey anti-apoptotic function in vitro. We describe here that human A1 mRNA is constitutively expressed in mature neutrophils and is up-regulated by G-CSF and LPS, agonists that promote neutrophil survival. In addition, we show progressive A1 mRNA accumulation in HL-60 cells during all-trans retinoic acid-driven neutrophilic differentiation. Our findings suggest that A1 may have an important role in neutrophilic development and in modulating mature neutrophil survival.

Fibroblast growth factor-2 inhibits endothelial cell apoptosis by Bcl-2-dependent and independent mechanisms

Intact endothelium acts as a sensor and transducer of signals and also provides a nonthrombogenic surface at the blood-vascular wall interface. Hence, mechanisms that maintain the integrity of the endothelium are of interest in physiological and pathological states. In this study we show that apoptosis induced by growth factor and serum deprivation of endothelial cells occurs at all phases of the cell cycle and can be blocked by fibroblast growth factor-2 (FGF-2) independently of its mitogenic activity. As the Bcl-2 family of proteins plays a prominent role in regulating cell survival, we attempted to identify Bcl-2 homologues expressed in endothelial cells. Here we demonstrate that, in addition to the previously identified A1, four other members of the Bcl-2 family, Bcl-2, Mcl-1, Bcl-X(L), and Bax, are expressed in endothelial cells. Of these family members, only Bcl-2 is induced by FGF-2. Overexpression of Bcl-2, using a retroviral vector, protects endothelial cells from serum and growth factor deprivation. There is no difference in FGF-2-induced proliferation between Bcl-2-overexpressing cells and those transduced with the empty retroviral vector. At early time points Bcl-2 is not up-regulated, but FGF-2 still has a protective effect. However, FGF-2 protects only adherent endothelial cells but not those that are cultured in suspension. The early effect of FGF-2 is dependent on tyrosine phosphorylation but not on activation of the MAP kinase pathway. Thus, FGF-2 inhibits endothelial cell apoptosis by Bcl-2-dependent and independent mechanisms.

Mice lacking the guanylyl cyclase C receptor are resistant to STa-induced intestinal secretion

Heat-stable enterotoxin (STa) is an important causative agent of diarrheal disease throughout the world. STa is known to bind specifically to receptors in the intestine, provoking intense intestinal secretion. Binding of STa, or of the mammalian endogenous ligands guanylin and uroguanylin, activates the guanylyl cyclase C receptor (GC-C); the resulting elevation of cGMP levels stimulates chloride secretion via CFTR. We have generated knockout mice which completely lack the GC-C receptor. These mice are viable and show no obvious alteration in intestinal fluidity. However, GC-C null mice are refractory to the secretory action of STa, proving that the GC-C receptor is necessary for the diarrheal response induced by STa.

Overexpression of metallothionein decreases sensitivity of pulmonary endothelial cells to oxidant injury

Metallothionein (MT) is a low-molecular-weight cysteine-rich protein with extensive metal binding capacity and potential nonenzymatic antioxidant activity. Despite the sensitivity of vascular endothelium to either heavy metal toxicity or oxidative stress, little is known regarding the role of MT in endothelial cells. Accordingly, we determined the sensitivity of cultured sheep pulmonary artery endothelial cells (SPAEC) that overexpressed MT to tert-butyl hydroperoxide (t-BOOH), hyperoxia, or 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN; peroxyl radical generator). Nontoxic doses of 10 microM Cd increased MT levels from 0.21 +/- 0.03 to 2.07 +/- 0.24 microg/mg and resulted in resistance to t-BOOH and hyperoxia as determined by reduction of Alamar blue or [3H]serotonin transport, respectively. SPAEC stably transfected with plasmids containing either mouse or human cDNA for MT were resistant to both t-BOOH and hyperoxia. In addition, we examined transition metal-independent, noncytotoxic AMVN-induced lipid peroxidation after metabolic incorporation of the oxidant-sensitive fluorescent fatty acid cis-parinaric acid into phospholipids and high-performance liquid chromatography separation. SPAEC that overexpressed MT after gene transfer completely inhibited peroxyl oxidation of phosphatidylserine, phosphatidylcholine, and sphingomyelin (but not phosphatidylethanolamine) noted in wild-type SPAEC. These data show for the first time that MT can 1) protect pulmonary artery endothelium against a diverse array of prooxidant stimuli and 2) directly intercept peroxyl radicals in a metal-independent fashion, thereby preventing lipid peroxidation in intact cells.

Endothelial cell death induced by tumor necrosis factor-alpha is inhibited by the Bcl-2 family member, A1

Endothelial cells play a central role in the inflammatory process. Tumor necrosis factor-alpha (TNF) is a multifunctional cytokine which elicits many of the inflammatory responses of endothelial cells. While TNF directly causes apoptosis of tumor cells and virally infected cells, normal cells are generally resistant. However, most resistant cells, including human endothelial cells, can be rendered susceptible to TNF by inhibiting RNA or protein synthesis. This finding suggests that TNF provides a cell survival signal in addition to a death signal. We have previously cloned a human Bcl-2 homologue, A1, and shown that it is specifically induced by proinflammatory cytokines but not by endothelial growth factors. In this study, we show that retroviral-mediated transfer of the A1 cDNA to a human microvascular endothelial cell line provides protection against cell death initiated by TNF in the presence of actinomycin D. The induction of A1 by TNF in this system is mediated via a protein kinase C pathway. Since TNF signaling has also been shown to proceed via ceramides, we tested whether exogenous ceramides could induce A1. Our findings indicate that ceramides do not induce A1 but do up-regulate c-jun and induce endothelial death. Ceramide-activated endothelial death is also inhibited by A1, suggesting that TNF may initiate divergent survival and death pathways via separate lipid second messengers.

5-Oxo-eicosanoids and hematopoietic cytokines cooperate in stimulating neutrophil function and the mitogen-activated protein kinase pathway

The newly defined eicosatetraenoates (ETEs), 5-oxoETE and 5-oxo-15(OH)-ETE, share structural motifs, synthetic origins, and bioactions with leukotriene B4 (LTB4). All three eicosanoids stimulate Ca2+ transients and chemotaxis in human neutrophils (PMN). However, unlike LTB4, 5-oxoETE and 5-oxo-15(OH)-ETE alone cause little degranulation and no superoxide anion production. However, we show herein that, in PMN pretreated with granulocyte-macrophage or granulocyte colony-stimulating factor (GM-CSF or G-CSF), the oxoETEs become potent activators of the last responses. The oxoETEs also induce translocation of secretory vesicles from the cytosol to the plasmalemma, an effect not requiring cytokine priming. To study the mechanism of PMN activation in response to the eicosanoids, we examined the activation of mitogen-activated protein kinase (MAPK) and cytosolic phospholipase A2 (cPLA2). PMN expressed three proteins (40, 42, and 44 kDa) that reacted with anti-MAPK antibodies. The oxoETEs, LTB4, GM-CSF, and G-CSF all stimulated PMN to activate the MAPKs and cPLA2, as defined by shifts in these proteins' electrophoretic mobility and tyrosine phosphorylation of the MAPKs. However, the speed and duration of the MAPK response varied markedly depending on the stimulus. 5-OxoETE caused a very rapid and transient activation of MAPK. In contrast, the response to the cytokines was rather slow and persistent. PMN pretreated with GM-CSF demonstrated a dramatic increase in the extent of MAPK tyrosine phosphorylation and electrophoretic mobility shift in response to 5-oxoETE. Similarly, 5-oxoETE induced PMN to release some preincorporated [14C]arachidonic acid, while GM-CSF greatly enhanced the extent of this release. Thus, the synergism exhibited by these agents is prominent at the level of MAPK stimulation and phospholipid deacylation. Pertussis toxin, but not Ca2+ depletion, inhibited MAPK responses to 5-oxoETE and LTB4, indicating that responses to both agents are coupled through G proteins but not dependent upon Ca2+ transients. 15-OxoETE and 15(OH)-ETE were inactive while 5-oxo-15(OH)-ETE and 5(OH)-ETE had 3- and 10-fold less potency than 5-oxoETE, indicating a rather strict structural specificity for the 5-keto group. LY 255283, a LTB4 antagonist, blocked the responses to LTB4 but not to 5-oxoETE. Therefore, the oxoETEs do not appear to operate through the LTB4 receptor. In summary, the oxoETEs are potent activators of PMN that share some but not all activities with LTB4. The response to the oxoETEs is greatly enhanced by pretreatment with cytokines, indicating that combinations of these mediators may be very important in the pathogenesis of inflammation.

5-Oxo-eicosatetraenoate is a broadly active, eosinophil-selective stimulus for human granulocytes

5-Oxo-eicosatetraenoate (5-oxoETE) is gaining recognition as a chemotactic factor for eosinophilic (Eo) as well as neutrophilic (Neu) polymorphonuclear leukocytes. We found that the eicosanoid was far stronger than C5a, platelet-activating factor (PAF), leukotriene B4 (LTB4), or FMLP in stimulating Eo chemotaxis. Moreover, it had weak intrinsic degranulating effects on otherwise unstimulated Eo, produced prominent degranulation responses in Eo primed by granulocyte-macrophage CSF, and enhanced the Eo-degranulating potencies of PAF, C5a, LTB4, and FMLP by up to 10,000-fold. Low picomolar levels of 5-oxoETE also induced Eo to activate mitogen-activated protein kinases (MAPKs), as defined by shifts in the electrophoretic mobility and tyrosine phosphorylation of two immunodetectable proteins, p44 and p42. 5-OxoETE was > or = 100-fold weaker or unable to stimulate any of these responses in Neu. Finally, 5-oxo-15-hydroxy-ETE and 5-hydroxy-ETE activated both cell types, but were weaker than 5-oxoETE and had Eo/Neu potency ratios approaching unity. 5-OxoETE, thus, is uniquely potent and selective in promoting Eo not only to migrate, but also to release granule enzymes and activate MAPKs. By triggering MAPK activation, the eicosanoid may also influence the production of anaphylactoid lipids (e.g., PAF), arachidonic acid metabolites, and cytokines. 5-OxoETE therefore possesses a biologic profile well suited for mediating Eo-dominated allergic reactions in vivo.

5-Oxo-eicosatetraenoate is a broadly active, eosinophil-selective stimulus for human granulocytes

5-Oxo-eicosatetraenoate (5-oxoETE) is gaining recognition as a chemotactic factor for eosinophilic (Eo) as well as neutrophilic (Neu) polymorphonuclear leukocytes. We found that the eicosanoid was far stronger than C5a, platelet-activating factor (PAF), leukotriene B4 (LTB4), or FMLP in stimulating Eo chemotaxis. Moreover, it had weak intrinsic degranulating effects on otherwise unstimulated Eo, produced prominent degranulation responses in Eo primed by granulocyte-macrophage CSF, and enhanced the Eo-degranulating potencies of PAF, C5a, LTB4, and FMLP by up to 10,000-fold. Low picomolar levels of 5-oxoETE also induced Eo to activate mitogen-activated protein kinases (MAPKs), as defined by shifts in the electrophoretic mobility and tyrosine phosphorylation of two immunodetectable proteins, p44 and p42. 5-OxoETE was > or = 100-fold weaker or unable to stimulate any of these responses in Neu. Finally, 5-oxo-15-hydroxy-ETE and 5-hydroxy-ETE activated both cell types, but were weaker than 5-oxoETE and had Eo/Neu potency ratios approaching unity. 5-OxoETE, thus, is uniquely potent and selective in promoting Eo not only to migrate, but also to release granule enzymes and activate MAPKs. By triggering MAPK activation, the eicosanoid may also influence the production of anaphylactoid lipids (e.g., PAF), arachidonic acid metabolites, and cytokines. 5-OxoETE therefore possesses a biologic profile well suited for mediating Eo-dominated allergic reactions in vivo.

Cloning of human Bcl-2 homologue: inflammatory cytokines induce human A1 in cultured endothelial cells

Bcl-2 is an intracellular membrane-associated protein that functions to block programmed cell death. Despite recurrent exposure to cellular toxins from the circulation and tissue, endothelial cells are remarkably resistant to cell death. Because Bcl-2 protein levels are low or undetectable in endothelial cells, we postulated that other members of the growing Bcl-2 family would be present in endothelial cells to provide protection against apoptosis. Degenerate primers to two conserved regions of the Bcl-2 family were used to amplify potential homologues in endothelial cells. This strategy resulted in the isolation of a human Bcl-2 homologue related to murine Al, a recently identified member of this family. We show here that, in endothelial cells, human Al is rapidly inducible by phorbol ester and the inflammatory cytokines, tumor necrosis factor-alpha and interleukin-1beta, but not by the growth factors, basic fibroblast growth factor or vascular endothelial growth factor. Al is the only known Bcl-2 family member that is inducible by inflammatory cytokines, suggesting that it may play a protective role during inflammation. Additionally, vascular smooth muscle cells and various nonhematopoietic tissues express human Al, indicating that human Al is a widely expressed Bcl-2 homologue.

Transfected leukocyte integrin CD11b/CD18 (Mac-1) mediates phorbol ester-activated, homotypic cell:cell adherence in the K562 cell line

The CD11b/CD18 leukocyte integrin molecule mediates diverse neutrophil adherence-related functions, including cell:cell and cell:extracellular matrix attachments. To study the individual role of this leukocyte integrin in cell adherence in hematopoietic cells, we expressed the CD11b/CD18 complex on the surface of K562 cells, a cell line derived from an individual with chronic myelogenous leukemia in blast crisis. We used an amphotrophic retroviral vector designated LCD18SN, harboring the complete coding sequence for the CD18 subunit, to transfer the CD18 cDNA into K562 cells and select stable cell lines. The CD11b subunit in the expression plasmid pREP4 was transfected into these K562/CD18 cells by electroporation and stable cell clones were selected. These K562 cells possessed RNA and intracellular protein for each subunit, and they expressed the CD11b/CD18 heterodimer on the cell surface. When CD11b/CD18 expressing K562 cells were stimulated with phorbol myristate acetate (50 ng/mL) for 24 to 48 hours, these K562 cells formed dense cell:cell aggregates. This homotypic aggregation required both activation of the CD11b/CD18 complex and the induction of the counter-receptor for CD11b/CD18 on the conjugate cell. This cell line will (1) enable the structure-function relationships between cell activation and homotypic adherence to be assessed, (2) provide the opportunity to identify accessory molecules required for activation of the CD11b/CD18 complex, and (3) facilitate the identification of novel ligands for the CD11b/CD18 complex.

Remote biodetection performance of a pulsed monostatic lidar system

A monostatic pulsed lidar system called the laser cloud mapper was operated at the lidar range facility at the Defence Research Establishment Valcartier for 2 weeks during the autumn of 1990 to determine and assess its sensitivity for the remote detection of airborne biological organisms. The methodology called for the measurement of the depolarization of the lidar return signals that were backscattered from a biological aerosol cloud introduced into a large outdoor aerosol chamber. The test aerosol was produced by aerosolization of bacterial spores suspended in tap water; the relative concentration (by volume) of the bacterial material in tap water was varied from 1.0 to 0.001%. The detection performance of the laser cloud mapper is characterized through the ordered statistics of the depolarization ratio (e.g., sample distribution functions, quantile-quantile plots, and shift functions). In addition, a robust detection statistic based on the a-trimmed mean has been considered and the bootstrap-resampling method has been utilized to estimate uncertainties or confidence limits for this statistic. The receiver-operating characteristic curves of the laser cloud mapper (i.e., the probability of detection, <p>P</p>(D), versus the probability of false alarm, P(FA)) for both the empirical distribution function and the linearly thresholded, trimmed mean-level detectors are presented as a function of the source concentration of the test aerosol.

Enzyme-linked immunosorbent assay for proteolytically inactivated antithrombin-III: use of sodium dodecyl sulfate to eliminate signal due to intact antithrombin-III

Antithrombin III (AT-III) is a serine protease inhibitor (serpin) that can be catalytically inactivated by human neutrophil elastase (HNE) without inhibiting HNE activity. As with catalytic inactivation of most serpins, the cleaved form of the inhibitor is difficult to measure in the presence of active inhibitor. One major difference between the cleaved and intact forms of AT-III is that the cleaved form adopts a more stable conformation. Using sodium dodecyl sulfate (SDS), we were able to devise an enzyme-linked immunosorbent assay (ELISA) capable of detecting cleaved AT-III in the presence of intact AT-III. It seems likely that the SDS alters the intact AT-III so that it is not detected in the ELISA. As little as 5 micrograms/ml HNE-cleaved AT-III could be detected when spiked into human plasma; HNE-cleaved AT-III spiked into human plasma at different levels was recovered as expected. Thrombin-cleaved AT-III was also detected using this ELISA. The generation of cleaved AT-III in human plasma by HNE in the presence of heparin could be monitored as well. The cleaved AT-III ELISA is a novel, yet simple way to measure proteolytically inactivated AT-III in the presence of intact AT-III and should be useful for studying the role of proteolytic inactivation of serpins such as AT-III in vivo.

A monoclonal antibody to beta 1 integrin (CD29) stimulates VLA-dependent adherence of leukocytes to human umbilical vein endothelial cells and matrix components

The leukocyte beta 1 integrin receptor very late activation antigen-4 (VLA-4) (alpha 4 beta 1, CD49d/CD29) binds to vascular cell adhesion molecule-1 (VCAM-1) expressed on cytokine-activated endothelium. A mAb designated 8A2 was identified that stimulated the binding of U937 cells to CHO cells transfected with VCAM-1 cDNA but not endothelial-leukocyte adhesion molecule or CD4 cDNA. mAb 8A2 also rapidly stimulated the adherence of peripheral blood lymphocytes (PBLs) to VCAM-1-transfected CHO cells or recombinant human tumor necrosis factor-treated human umbilical vein endothelial cells. mAb 8A2-stimulated binding of PBL was inhibited by mAbs to VLA-4 or VCAM-1. Surface expression of VLA-4 was not altered by mAb 8A2 treatment and monovalent Fab fragments of mAb 8A2 were active. Immunoprecipitation studies reveal that mAb 8A2 recognizes beta 1-subunit (CD29) of integrin receptors. In contrast to mAbs directed to VLA-4 alpha-subunit (alpha 4, CD49d), mAb 8A2 did not induce homotypic aggregation of PBL. Additionally, mAb 8A2 stimulated adherence of PBL and hematopoietic cell lines to purified matrix components laminin and fibronectin. This binding was blocked by mAbs to the VLA alpha-subunits alpha 6 (CD49f), or alpha 5 (CD49e) and alpha 4 (CD49d), respectively. We conclude that mAb 8A2 modulates the affinity of VLA-4 and other leukocyte beta 1 integrins, and should prove useful in studying the regulation of beta 1 integrin function.

Intracellular pH of tissue-cultured bovine corneal endothelial cells

Intracellular pH (pHi) of bovine tissue-cultured corneal endothelial cells has been measured under several experimental conditions. Determinations were made on individual cells using video-imaging techniques that allowed assessment of 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein fluorescence at 440 and 490 nm. Each experiment had a calibration performed on a cell monolayer: this was performed using a high K(+)-nigericin solution. Resting pHi was 7.25 +/- 0.03 (n = 18) in bicarbonate solution at pH 7.4. Amiloride (1 mM) caused an acidification of approximately 0.2 U within 2 min: replacement with normal Ringer allowed a return to normal pHi after an alkali overshoot. Exposure to 20 mM NH4Cl caused alkalinization that became acidic upon washout of NH4Cl. In Na(+)-rich solution pHi returned to normal after acidification but pHi remained low in Na(+)-free solution until substituted by Na(+)-rich solution. Removal of HCO3- from the bathing solution caused a nonsignificant acidification of pHi by 0.1 U at 2 and 4 min, and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS; 1 mM) acidified pHi by 0.14 U at 2 min and 0.24 U at 4 min. Addition of DIDS (1 mM) in a HCO3(-)-free solution had no effect on pHi. Hydrogen peroxide acidified pHi by 0.3 U at 50 microM and 1 mM. These results indicate that a Na+:H+ antiport exists that regulates pHi even at normal ambient pH in the presence of bicarbonate: this process becomes highly activated after an acid load. There is a DIDS-sensitive HCO3- movement that is probably coupled to Na+ or Cl-.

Reconstruction of the antibody affinity distribution from experimental binding data by a minimum cross-entropy procedure

A new solution is presented for the reconstruction of the distribution of association constants of antigen-antibody binding from a finite number of noisy experimental binding data. This ill-posed problem is solved by utilizing an information-theoretic method based on the principle of minimum cross-entropy (MCE) to select, as the solution, that unique antibody binding distribution which minimizes the cross entropy relative to some prior distribution subject to the constraints imposed by the given measurements. The prior distribution is selected to properly encode all the a priori information on the affinity distribution before the measurement of the experimental binding data. The utility of the method is demonstrated by application to synthetic binding data.

Ventricular tachycardia with congenital ventricular diverticulum

A 24-year-old man presented with symptomatic, recurrent, sustained ventricular tachycardia (VT). He was found to have a basal inferior left ventricular diverticulum. His sustained VT was reproduced by programmed electrical stimulation and was unresponsive to procainamide, tocainide, propafenone, and flecainide. Endocardial mapping followed by resection and cryoablative surgery was performed. The patient had only one recurrence after 18 months, with subsequent control with procainamide for over 14 months.

The SCID-hu mouse: a small animal model for HIV infection and pathogenesis

The SCID-hu mouse is a heterochimeric small animal model designed to support hematopoietic differentiation and function in vivo. Multiple organs of the human hematolymphoid system have been successfully engrafted into the immunodeficient C.B-17 scid scid mouse, including fetal liver, thymus, lymph node, and skin. Co-implantation of human fetal liver and human fetal thymus results in long-term, multilineage human hematopoiesis in vivo. Mature human lymphocytes within the SCID-hu mouse are phenotypically and functionally normal. HIV infection of the SCID-hu mouse reflects a tropism similar to that found in humans: only human organs with CD4+ cells are infected. Viral replication can thereafter be monitored with assays that are safe, reproducible, and quantitative. Given this small animal model, it is now possible to study systematically the infective process of HIV and to address questions about the efficacy of novel antiviral compounds or vaccines in vivo.

Vascular cell adhesion molecule-1 mediates lymphocyte adherence to cytokine-activated cultured human endothelial cells

The expression and function of a new cytokine-induced endothelial cell adhesion protein, vascular cell adhesion molecule-1 (VCAM-1), was characterized in vitro by using a monoclonal antibody, MoAb 4B9, which recognizes a functional epitope on this protein. As determined by enzyme-linked immunosorbent assay and radioimmunoprecipitation of metabolically labeled cells, VCAM-1 was minimally expressed on unstimulated human umbilical vein endothelium (HUVE), but was rapidly induced by recombinant human tumor necrosis factor-alpha (rhTNF-alpha), rh interleukin-1, and lipopolysaccharide. In contrast to intercellular adhesion molecule-1, VCAM-1 was not induced on dermal fibroblasts or arterial smooth muscle cells after stimulation with rhTNF, or on keratinocytes after stimulation with rh interferon-gamma. MoAb 4B9 significantly inhibited the adherence of peripheral blood lymphocytes (PBL) and lymphocytic cell lines, but not neutrophils, to rhTNF-activated HUVE. The inhibitory effect of MoAb 4B9 on PBL adherence to HUVE was additive to that produced by the CD18 MoAb 60.3. These results show that VCAM-1 mediates a CD18-independent pathway of peripheral blood lymphocyte adherence to cytokine-stimulated HUVE. We propose that lymphocyte binding to VCAM-1, induced on endothelium by cytokines, may be an important component of lymphocyte emigration at sites of inflammation or immune reaction.

Lipid IVA inhibits synthesis and release of tumor necrosis factor induced by lipopolysaccharide in human whole blood ex vivo

Tumor necrosis factor (TNF) released by lipopolysaccharide (LPS)-stimulated mononuclear phagocytes is a critical mediator of sepsis. We examined the capacities of rough mutant Salmonella typhimurium LPS (Rc) and LPS partial structures lipid A, monophosphoryl lipid A (MPLA), lipid IVA, and lipid X to induce production of TNF in whole blood. Rc LPS (0.0001-10 ng/ml) produced a dose-dependent release of TNF as determined by cytotoxicity of actinomycin D-sensitized L929 murine fibroblasts. Lipid A, MPLA, lipid IVA, and lipid X exhibited decreasing capacities to stimulate production of TNF in whole blood, respectively. Fractional deacylation of LPS by incubation with acyloxyacyl hydrolase isolated from human leukocytes produced a reduction in the capacity of LPS to induce TNF release in whole blood. Maximal enzymatic deacylation reduced activity of LPS by greater than 100-fold. Coincubation with lipid IVA inhibited TNF release induced by Rc LPS or lipid A, but not by phorbol ester. In contrast, MPLA, lipid X, and deacylated LPS failed to inhibit LPS-stimulated release of TNF. Corresponding to the inhibition of the release of TNF protein, lipid IVA also inhibited the accumulation of TNF mRNA in LPS-stimulated mononuclear cells. These results suggest that lipid IVA may act as a competitive antagonist of LPS, perhaps at the receptor level.

Neural network recognition and classification of aerosol particle distributions measured with a two-spot laser velocimeter

This paper describes the use of a neural computational network model for pattern recognition and classification of aerodynamic particle size distributions associated with a number of environmental, bacterial, and artificial aerosols. The aerodynamic particle size distributions are measured in real time with high resolution using a two-spot He-Ne laser velocimeter. The technique employed here for the recognition and classification of aerosols of unknown origin is based on a three-layered neural network that has been trained on a training set consisting of 75 particle size distributions obtained from three distinct types of aerosols. The training of the neural network was accomplished with the back-propagation learning algorithm. The effects of the number of processing units in the hidden layer and the level of noise corrupting the training set, the test set, and the connection weights on the learning rate and classification efficiency of the neural network are studied. The ability of the trained network to generalize from the finite number of size distributions in the training set to unknown size distributions obtained from uncertain and unfamiliar environments is investigated. The approach offers the opportunity of recognizing, classifying, and characterizing aerosol particles in real time according to their aerodynamic particle size spectrum and its high recognition accuracy shows considerable promise for applications to rapid real-time air monitoring in the areas of occupational health and air pollution standards.

Use of DBA/2N mice in models of systemic candidiasis and pulmonary and systemic aspergillosis

Mouse models of systemic candidiasis and pulmonary and systemic aspergillosis were established by using DBA/2N mice, which are known to be deficient in the C5 component of complement. In experiments comparing lethality in the respective models in DBA/2N versus outbred CFW mice, results showed that the 50% lethal dose values for the DBA/2N mice were 10- to 1,000-fold lower than those for the outbred mice, depending on the experiment. Additionally, onset of death was somewhat delayed for the DBA/2N mice. In the case of the pulmonary aspergillosis model, administration of cortisone acetate was necessary to ensure lethality after intranasal infection, but only a single dose was necessary.

Evaluation of Bay R 3783 in rodent models of superficial and systemic candidiasis, meningeal cryptococcosis, and pulmonary aspergillosis

The triazole Bay R 3783 was compared with fluconazole, itraconazole, ketoconazole, and amphotericin B in rodent models of superficial and systemic candidiasis, meningocerebral cryptococcosis, and pulmonary aspergillosis. Overall, Bay R 3783 was comparable or slightly superior to fluconazole and markedly superior to itraconazole and ketoconazole in both survival and short-term organ load experiments in models of candidiasis and cryptococcosis but was less effective than amphotericin B. Of the antifungal agents tested, only Bay R 3783 and itraconazole showed any efficacy in the model of pulmonary aspergillosis.

Information-theoretic method for the inversion of the lidar equation

A new solution is presented for the reconstruction of profiles of aerosol volume extinction coefficients from the noisy backscattered returns of a monostatic single-wavelength lidar system. This inverse problem is solved by utilizing an information-theoretic method based on the principle of minimum cross-entropy (MCE), which represents an objective and rational approach for the effective incorporation, into the inversion procedure, of both prior information in the form of an initial estimate of the extinction coefficient and additional information in the form of the observed lidar data. A simple and robust numerical procedure, based on the ellipsoid algorithm, is developed to compute the MCE reconstruction of the extinction function. A number of numerical examples, based on noisy synthetic lidar data, are employed to demonstrate and evaluate the utility and efficacy of the inversion method.

Scintigraphic assessment of regional cardiac adrenergic innervation

To assess the feasibility of noninvasively imaging the regional distribution of myocardial sympathetic innervation, we evaluated the distribution of sympathetic nerve endings, using 123I metaiodobenzylguanidine (MIBG), and compared this with the distribution of myocardial perfusion, using 201Tl. Twenty dogs were studied: 11 after regional denervation, and nine as controls. Regional denervation was done by left stellate ganglion removal, right stellate ganglion removal, and application of phenol to the epicardial surface. Computer-processed functional maps displayed the relative distribution of MIBG and thallium in multiple projections in vivo and excised heart slices in all animals. In six animals, dual isotope emission computed tomograms were acquired in vivo. Tissue samples taken from innervated and denervated regions of the MIBG images were analyzed for norepinephrine content to validate image findings. Normal controls showed homogeneous and parallel distributions of MIBG and thallium in the major left ventricular mass. In the left stellectomized hearts, MIBG was reduced relative to thallium in the posterior left ventricle; whereas in right stellectomized hearts, reduced MIBG was in the anterior left ventricle. Phenol-painted hearts showed a broad area of decreased MIBG extending beyond the area of phenol application. In both stellectomized and phenol-painted hearts, thallium distribution remained homogeneous and normal. Norepinephrine content was greater in regions showing normal MIBG (550 +/- 223 ng/g) compared with regions showing reduced MIBG (39 +/- 44 ng/g) (p less than 0.001), confirming regional denervation. Combined MIBG-thallium functional maps display the regional distribution of sympathetic innervation. This new ability to noninvasively map the distribution of sympathetic nerves with simultaneous comparison to regional perfusion may provide important new insights into mechanisms, whereby an imbalance in sympathetic activity may relate to clinical disorders.

Minimum cross-entropy inversion of satellite photometer data

The inversion of satellite photometry data to produce a 2-D distribution of volume emission rate of optical emissions in the upper atmosphere does not provide a unique solution, but this problem may be alleviated by the application of the minimum cross-entropy (MCE) principle. This principle provides a rational criterion of choice for the selection of that distribution of volume emission rate which is maximally noninformative a subject to the constraints imposed by the data (namely, the integrated column brightness measurements). A practical and effective iterative algorithm is developed to compute the MCE reconstruction of volume emission rates. This algorithm is then applied to both synthetic and real satellite photometer data to demonstrate the effectiveness of the proposed inversion scheme.

Magnetic resonance imaging of cardiac transplants: the evaluation of rejection of cardiac allografts with and without immunosuppression

The purpose of this study was to evaluate the potential of magnetic resonance imaging (MRI) in vivo for the characterization of tissue changes associated with acute myocardial rejection after cardiac transplantation. Of 15 dogs that underwent heterotopic cardiac transplantation, six served as untreated controls, and nine received immunosuppressive therapy (25 mg/kg/day cyclosporine, 1 mg/kg/day prednisone). Serial electrocardiographically gated MRI (spin-echo technique) and histologic examinations of allograft biopsy samples were performed for each dog at 2 to 3, 7 to 10, 14 to 17, and 26 to 29 days after transplantation and immediately after animals were killed. Untreated allografts showed a significant increase (p less than .01) in T2 (spin-spin) relaxation time (T2 = 66 +/- 8 msec) and intensity values compared with values in the native hearts (T2 = 44 +/- 6 msec) as early as 1 week after transplantation. The significant difference in T2 values could be observed in vivo as well as on postmortem examination and corresponded to histologic progression of the rejection process. There was no significant difference in T1, T2, or intensity values in cyclosporine-treated allografts and native hearts except in two dogs in which T2 relaxation times and signal intensity in the transplanted hearts increased simultaneously with histologic evidence of rejection, indicating failure of immunosuppressive therapy. There was a significant correlation between histologic grading of severity of rejection and T2 relaxation times of the cardiac transplants (r = .72). Likewise, there was a significant linear relationship between T2 values in vivo and percent water content when the differences between native hearts and allografts were compared (r = .92, p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet factor-4 excretion in myeloproliferative disease: implications for the aetiology of myelofibrosis

Experimental evidence suggests that the fibroblastic proliferation often associated with the myeloproliferative disorders is not part of the neoplastic process, but is secondary to an unknown stimulus. This stimulus may be a factor derived from platelets which promotes the proliferation of fibroblasts in vitro (PDGF). Platelet-derived growth factor is localized to platelet alpha-granules together with PF4 and beta-TG. As an indicator of alpha-granule release, we have measured PF4 levels in plasma, platelets and urine in 46 normal subjects and 49 patients with myeloproliferative disorders, secondary thrombocytosis and miscellaneous malignancies. All 11 patients with elevated urinary PF4 excretion exhibited myelofibrosis, whereas 11 of 22 patients with documented myelofibrosis had urinary PF4 excretion in the normal range. No correlation was seen between marrow fibrosis and plasma levels or the platelet content of PF4. The data are consistent with the possibility that release of mitogen(s) from platelet or megakaryocyte alpha-granules in some patients with myeloproliferative disorders is pathogenetically related to the development of marrow fibrosis.

Segmental mastectomy without radiotherapy. Short-term follow-up

Short-term treatment failures following 43 segmental mastectomies without radiation therapy and 157 total mastectomies for primary operable breast cancer Stages I and II (T1-2, N0-1, M0) are compared. Although not randomized by design, the patients in the two treatment groups were of similar age and had tumors of comparable histologic type, size, grade, and stage. The overall recurrence rates in an average follow-up of 24 months (range, 6-48 months) were 5% for patients treated by standard mastectomy and 19% for those treated by segmental mastectomy. Recurrence rates in patients with the more commonly encountered carcinomas of 11 to 50 mm in size treated by surgery alone were 7.5% for total mastectomy and 28.0% for segmental mastectomy. Nearly all of this difference relates to a higher frequency of local recurrence in the segmental mastectomy group (P = less than 0.005). Recurrent disease in both groups developed at comparable intervals, averaging 17 months for segmental mastectomy and 16 months for total mastectomy. Using a serial subgross technique, which permitted detection of clinically unsuspected involvement of resection margin by microscopic foci of carcinoma, it was noted that such involvement was an important prognostic indicator for local recurrence. Five of eleven breast resections with this feature developed local recurrence, compared with only 3 of 32 without such involvement of the resection margin.

Parathyroid hormone and triglyceride transport: effects on triglyceride secretion rates and adipose tissue lipoprotein lipase in the rat

In order to determine the effects of parathyroid hormone on triglyceride transport, male Sprague-Dawley rats were injected with parathyroid extract for eight days and triglyceride secretion rates (TGSR) and adipose tissue lipoprotein lipase (LPL) activity were determined. Parathyroid hormone-treated rats demonstrated significantly lower (p less than .005) TGSR in the basal overnight fasted state 15 hours after the previous injection, but this effect on TGSR was not apparent 3 hours after PTE injection when the rats were allowed to eat. In contrast, LPL activity was significantly reduced in the PTH-treated animals at 3 hours and no effect was apparent on this index of triglyceride removal at 15 hours. These findings suggest that parathyroid hormone may exert independent influences on triglyceride production and removal and thus may alter triglyceride homeostasis in conditions in which parathyroid hormone levels are abnormally increased.