Altered distribution of intraglomerular immune complexes in C3-deficient mice

We have studied the role of complement in a model of glomerular inflammation induced by the in situ formation of immune complexes along the glomerular basement membrane. In C3-deficient mice, produced by homologous recombination, immune complex formation occurs initially in the subendothelial site and progresses slowly to the subepithelial position, whereas wild-type mice do not develop subendothelial deposits. In addition, the accumulation of electron-dense deposits is greater in the complement-deficient mice. Complement therefore influences glomerular handling of immune complexes, possibly because of changes in the physiochemical characteristics of the immune complexes. However, despite evidence of complement activation in the wild-type mice, as demonstrated by immunohistochemical detection of C3, C4 and C9, the degree of proteinuria was similar in C3-deficient mice. We conclude that, although complement is required for the normal glomerular metabolism of immune complexes, other, complement-independent, factors are involved in the generation of glomerular injury in this model.

Letter from the Southwest: A medicine man and a lesson learned

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The effect of text coherence and modality on metamemory judgements

This study examined the effects of text coherence and modality on the metamemory judgements of Ease of Learning (EOL) and Judgement of Learning (JOL), and on the object-level measure of recall. Previous work found that sentence material set in a coherent, ordered text context was not judged as more memorable than that presented in a context of sentences in a disordered sequence, even though an ordered sequence helped recall (Shaddock & Carroll, 1997). The current study modified Shaddock and Carroll's design by changing the texts used from expository to narrative text. The metamemory judgements and recall were now found to be significantly more sensitive to material learned in an ordered sequence than to material learned in a disordered sequence. Also, JOLs and recall were more sensitive to material that was originally learned in an auditory mode (spoken presentation) than in a visual mode (verbal presentation). The results are discussed in terms of a cue-utilisation approach to metamemory judgements.

The effect of a video character's smoking status on young females' perceptions of social characteristics

Despite public warnings of the health risks associated with cigarette smoking, as well as advertising bans and educational programs in schools, the percentage of young females who smoke is on the rise. This study examined the effect of a video character's smoking status on young females' perceptions of social characteristics. University students were shown a video of a young woman in a socially oriented role-play. The video portrayed a smoker for the experimental group and a nonsmoker for the control group; in all other respects the video presentations were identical. Both groups answered a questionnaire pertaining to social characteristics they believed she possessed. The experimental group rated the character as more outgoing, more sophisticated, not as easy to manipulate, and less emotional about breaking up with her boyfriend than did the control group. There were no significant differences in ratings of her uncertainty in a crowd, her degree of unpopularity, her ability to be intimidated, the degree others admire her, and her attractiveness. The results are discussed in the light of previous studies, and implications for future research are explored.

Awareness of remembering achieved through automatic and conscious processes in multiple sclerosis

Fifty multiple sclerosis (MS) and forty-one matched control subjects were administered a word stem completion task and the California Verbal Learning. Test (CVLT). As predicted, priming in a conventional "implicit" task did not differ for MS and control groups, and under "explicit" instructions verbal list recall was significantly lower in the MS group with recognition intact. Application of the process dissociation procedure (Jacoby, Toth, & Yonelinas, 1993) to the word stem task demonstrated that conscious and unconscious processes both contribute to remembering in MS. Exploratory analyses found no group differences in words remembered under inclusion nor exclusion conditions, though preliminary estimates for MS automatic processing exceeded those for controls. As predicted, prospective metamemory judgments reflected subsequent performance for both groups in the inclusion but not the exclusion condition. By contrast, retrospective monitoring for both groups reflected memory performance in both conditions. However post hoc analyses demonstrated that those MS subjects who employed more automatic processing were less aware retrospectively of their successful remembering under exclusion than MS subjects who used less automatic processing.

Cellular but not plasma pharmacokinetics of lometrexol correlate with the occurrence of cumulative hematological toxicity

Lometrexol inhibits the first folate-dependent enzyme in de novo purine biosynthesis and is avidly polyglutamated and retained in tissues expressing folylpolyglutamate synthetase. Although clinical studies have been limited by cumulative toxicity, preclinical studies show that pretreatment with folic acid can protect normal tissue while maintaining tumor cytotoxicity. Therefore, a Phase I study of lometrexol every 21 days preceded by i.v. folic acid was initiated. Lometrexol was studied in six patients at 15 mg/m2, in six patients at 20 mg/m2, in three patients at 25 mg/m2, and in nine patients at 30 mg/m2. Patients received either 5 mg of folic acid 1 h before or 25 mg/m2 3 h before lometrexol. Blood samples were obtained around the first course and weekly thereafter for determination of plasma and erythrocyte (RBC) lometrexol concentrations. Bioactive folates in plasma and RBCs were determined in a subset of patients. Lometrexol pharmacokinetics were best described by a three-compartment model. Mean clearance and volume of distribution were 1.6 +/- 0.6 liters/h/m2 and 8.9 +/- 4.1 liters/m2. Mean half-lives were 0.23 +/- 0.1, 2.9 +/- 1.4, and 25.0 +/- 48.7 h. Pharmacokinetics were independent of either lometrexol or folic acid dose. In the weekly blood samples, RBC lometrexol levels rose, long after plasma lometrexol was undetectable. RBC lometrexol levels were independent of folic acid or lometrexol dose. Bioactive folates measured in plasma and RBCs during this same time period did not accumulate. Rising RBC levels were correlated with a fall in hematocrit, hemoglobin, and platelet count. This study indicates that the cumulative toxicity of lometrexol is related to tissue concentration and not plasma pharmacokinetics. RBC lometrexol may be an indicator of cumulative drug exposure and effect.

The agenda of the organization. 2: Interventions

Many contemporary organizations, though doing well in productivity, are in chaos. Stress amongst managers and employees is still rampant and the assertion that 'people are our best assets' is confirmed more in words than in actions. What interventions are needed to best add value to the agenda of the organization and influence employee performance for the better? A philosophy of employee care includes looking at how managers take responsibility for performance management, deal with their own and others' stress and how the dynamics within organizations can be understood and harnessed for the welfare of the company. It also includes reviewing, articulating and implementing policies and systems that affect individuals in the organization and the organization as a whole.

Comparison of rocuronium and suxamethonium for use during rapid sequence induction of anaesthesia

This study was designed to compare the tracheal intubating conditions during a rapid sequence induction of anaesthesia using rocuronium 0.6 (n = 61) or 1.0 mg.kg-1 (n = 130) or suxamethonium 1.0 mg.kg-1 (n = 127) as the neuromuscular blocking drugs. Anaesthesia was induced with fentanyl 1-2 micrograms.kg-1 and thiopentone 5 mg.kg-1 (median dose) and intubating conditions were assessed 60s after the administration of the neuromuscular blocking drug by an observer unaware of which drug had been given. Intubating conditions were graded on a three-point scale as excellent, good or poor, the first two being considered clinically acceptable. The study was carried out in two parts. At the end of the first part a comparison between the two doses of rocuronium was carried out when at least 50 patients had been enrolled in each group. The results showed the intubating conditions to be significantly superior with the 1.0 mg.kg-1 dose of rocuronium (p < 0.01). Final comparison between the 1.0 mg.kg-1 doses of rocuronium and suxamethonium showed no significant difference in the incidence of acceptable intubations (96 and 97%, respectively). The incidence of excellent grade of intubations was, however, significantly higher with suxamethonium (80% vs. 65%; p = 0.02). It is concluded that rocuronium 1.0 mg.kg-1 can be used as an alternative to suxamethonium 1.0 mg.kg-1 as part of a rapid sequence induction provided there is no anticipated difficulty in intubation. The clinical duration of this dose of rocuronium is, however, 50-60 min.

The agenda of the organization. 1: A framework

It is difficult at times to know if the welfare and well-being of an organization is being best served by the individuals who make decisions on its behalf. Sometimes decisions made are driven more by the needs of individual persons rather than by the needs of the organization. Company politics, conflicts, work relationships, territory and turf, individual status and power and personality issues all influence what happens and how decisions are made. Major decisions in areas such as downsizing, re-organization and corporate strategy are often made by individuals. Do these decisions best suit the agenda of the organization or reflect the agenda of the individual? Who looks after the organizational agenda? Noer's (1993) model is used to illustrate how what is best for the organization, and not just individuals within it, can be attained.

Instructions for ambulatory surgery--patient comprehension and compliance

Ambulatory surgery has proliferated as a result of increasing inpatient costs. Its high level of safety has resulted in its extension to less healthy, often elderly patients. Patient compliance with instructions is essential to avoid morbidity. We aimed to identify subgroups potentially at risk due to non-compliance. A confidential questionnaire was administered to 220 consecutive daycase patients. Data included: patient demographics, duration of fasting, taking of medications that morning, importance of fasting and medication instructions, mode of post-discharge transport, and whether they had someone to stay with them that night. Seven (3.5 per cent) patients admitted to non-compliance with fasting instructions, with 8 per cent considering these instructions non-essential. Thirteen of 59 patients on medications took them against instructions, with 9 patients considering the instructions non-essential. Eight patients admitted intending to drive home; 7 per cent admitted to having no one to stay with them on the night of surgery. A significantly minority of patients (particularly male) admit to non-compliance with ambulatory surgery instructions; these figures may be underestimates. Absence of anaesthetic/medical input and lack of reinforcement probably contribute to non-compliance. Some medication-related non-compliance may be appropriate (e.g. antianginals, antihypertensives) and may reflect conflicting instructions given to the patient. The stopping of all medications prior to ambulatory surgery needs revision. Older patients living alone may not be suitable candidates for ambulatory anaesthesia.

Phase I trial of intraperitoneal iododeoxyuridine with and without intravenous high-dose folinic acid in the treatment of advanced malignancies primarily confined to the peritoneal cavity: flow cytometric and pharmacokinetic analysis

In this Phase I study, the maximally tolerated doses (MTDs) of i.p. iododeoxyuridine (IdUrd) alone and in combination with i.v. calcium leucovorin (LV) were determined. The pharmacokinetics and pharmacological advantage of IdUrd were evaluated, and flow cytometric analysis allowed examination of the extent of incorporation of IdUrd into tumor cells with and without the addition of i.v. LV. Thirty-nine patients with advanced neoplasms primarily confined to the peritoneal space were enrolled in a dose-escalation trial using 4-h dwells of IdUrd administered i.p. daily for 4 days with and without an i.v. infusion of LV 500 mg/m2/day for 4.5 days. Twenty-three patients received single-agent therapy, and 13 patients received i.p. IdUrd in combination with i.v. LV. The MTD of single-agent IdUrd administered on this schedule was 4125 mg/m2/day for 4 days; and that of the IdUrd in combination was 3438 mg/m2/day. Dose-limiting toxicities were myelosuppression and stomatitis. During the period of the dwell, the peritoneal AUC (area under the curve) of IdUrd exceeded the plasma AUC of IdUrd by one or two orders of magnitude in all patients at all doses tested; there was a possible effect of LV on peritoneal AUC. The geometric mean pharmacological advantage (AUCperitoneal/ AUCplasma) was 181 at 625 mg/m2/day and 90 at 4538 mg/m2/day. Flow cytometric analysis suggests saturation of IdUrd measured in DNA at the 2500-3125 mg/m2 dose level, without an increase after the addition of LV. Twelve patients received 4-12 courses of therapy. One patient with recurrent ovarian cancer who received 16 courses of therapy experienced complete resolution of her ascites, near normalization of CA-125 levels, and improved quality of life; two patients with high-risk tumors receiving "adjuvant" therapy are disease-free at 3 and 6 years after treatment; other patients experienced transient clearing of ascites. The recommended Phase II dose of i.p. IdUrd using a 4-h dwell daily for 4 days is 3750 mg/m2/day alone or 3125 mg/m2/day in combination with continuous i.v. LV at 500 mg/m2/day for 4.5 days. Although flow cytometric data suggest that DNA incorporation of IdUrd is not affected by the addition of LV, the cytotoxicity of the combination regimen may be increased due to LV-enhanced, IdUrd-related inhibition of thymidylate synthase. For this reason, we recommend that efficacy studies of the combination continue in parallel with studies of IdUrd alone.

Enhanced B-1 cell development, but impaired IgG antibody responses in mice deficient in secreted IgM

The role of endogenous natural IgM in promoting the adaptive Ab response was investigated in newly constructed mutant mice in which B cells do not secrete IgM but still express surface IgM and IgD and undergo class switching to express other Ig isotypes. While the mutant mice had relatively normal numbers of conventional B (B-2) cells in all tissues examined, unexpectedly, B-1 cells in the peritoneum and spleen were approximately threefold more abundant. The elevated levels of B-1 cells were already detectable at 4 wk of age and were stably maintained throughout life. The levels of serum IgG2a, IgG3, and IgA were also elevated in the mutant mice at an early age. IgG2a response to a T cell-independent Ag was augmented, whereas IgG Ab responses to suboptimal doses of a T cell-dependent Ag were impaired. The latter defect was associated with fewer splenic germinal centers, impaired Ab affinity maturation, and less Ag trapping on follicular dendritic cells. Together, these findings demonstrate a physiologic role of natural IgM in the feedback regulation of B-1 cell development, the regulation of IgG2a production, and the promotion of efficient B-2 cell Ab responses.

CGP 57148, a tyrosine kinase inhibitor, inhibits the growth of cells expressing BCR-ABL, TEL-ABL, and TEL-PDGFR fusion proteins

CGP 57148 is a compound of the 2-phenylaminopyrimidine class that selectively inhibits the tyrosine kinase activity of the ABL and the platelet-derived growth factor receptor (PDGFR) protein tyrosine kinases. We previously showed that CGP 57148 selectively kills p210BCR-ABL-expressing cells. To extend these observations, we evaluated the ability of CGP 57148 to inhibit other activated ABL tyrosine kinases, including p185BCR-ABL and TEL-ABL. In cell-based assays of ABL tyrosine phosphorylation, inhibition of ABL kinase activity was observed at concentrations similar to that reported for p210BCR-ABL. Consistent with the in vitro profile of this compound, the growth of cells expressing activated ABL protein tyrosine kinases was inhibited in the absence of exogenous growth factor. Growth inhibition was also observed with a p185BCR-ABL-positive acute lymphocytic leukemia (ALL) cell line generated from a Philadelphia chromosome-positive ALL patient. As CGP 57148 inhibits the PDGFR kinase, we also showed that cells expressing an activated PDGFR tyrosine kinase, TEL-PDGFR, are sensitive to this compound. Thus, this compound may be useful for the treatment of a variety of BCR-ABL-positive leukemias and for treatment of the subset of chronic myelomonocytic leukemia patients with a TEL-PDGFR fusion protein.

Auditory context and memory retrieval in young infants

Three-month-old infants were trained to move an overhead crib mobile while 1 of 2 musical selections was played. Retention was assessed 1 or 7 days later in the presence of either the same music or a different musical selection. In Experiment 1, the musical selections were very different (classical versus jazz); in Experiment 2, they were much more similar (two classical pieces). Infants in both experiments displayed 1 day retention regardless of which music was played during the retention test. At 7 days, retention was seen only when the music played during the retention test matched the training music. These data are consistent with similar findings showing that 3-month-old infants' memory is disrupted at long retention intervals when the context present during retention testing does not match the learning context. As the infant's memory wanes, context appears to function as a necessary cue for the retrieval of acquired expectancies.

The effect of context and metamemory judgements on automatic processes in memory

These experiments examine two aspects of the automatic influences on memory as measured by target responding in the exclusion condition within the process dissociation framework. In Experiment 1, we examine the extent to which congruency between study and test contexts affects automatic processes in memory. In Experiment 2, we investigate qualitative differences in consciously controlled and automatic processing as indexed by metamemory judgements. In both experiments, a process-dissociation procedure was used to separate automatic and consciously controlled uses of memory in a stem completion task. In the study phase of Experiment 1, subjects read a passage from one of two directed perspectives. The subsequent stem completion task, which subjects performed while mindful of the study perspective, contained (a) old words congruent with the directed perspective, (b) old words congruent with a different (non-directed) perspective, and (c) words that had not been presented. Estimates of automatic influences for words congruent with the directed perspective were found to be greater than estimates for words incongruent with the directed perspective. These results provide evidence for the automatic or unconscious influences of meaning on task performance, which is uncontaminated by the influence of consciously controlled recollection which may occur in indirect memory tests. In Experiment 2, judgements of learning made prior to retrieval under inclusion and exclusion instructions were found to be different for consciously controlled and automatic processes, suggesting that memory as measured by the opposition (exclusion) procedure is involuntary and unconscious, with prospective monitoring of performance not sensitive to eventual performance.

Heat shock protein 70 expression in native and heterotopically transplanted rat hearts

Heat shock proteins (hsp) are intracellular proteins that are rapidly synthesized in response to a variety of stress factors. Recent studies in rats have shown that these proteins can elicit a lymphocyte response during cardiac allograft rejection. We studied the expression of the inducible (i) and constitutive (c) forms of hsp70 in rat cardiac allograft and isograft recipients to evaluate their utility as indicators of transplant rejection. Heterotopic transplantation of rat hearts was performed, using Lewis to Lewis isografts and ACI to Lewis allografts. Sham-operated rats were used as controls. Transplanted isograft, allograft, and native hearts of the transplant recipients and their livers and spleens were harvested at 5 days posttransplant and analyzed for hsp70 (i) and (c) expression by Western blots. Seven animals were studied in each group. Isografts at 3 and 60 days and allografts at 8 days were also studied. Quantification of band densities was carried out by laser densitometry. Physiological function of the native hearts of the transplant recipients was studied using Langendorff preparations. High levels of hsp70 (i) were noted in the transplanted and native hearts of the transplant recipients but not in their livers or spleens or in the hearts of the sham-operated control animals. Myocardial function of the native hearts of the transplant recipients was not significantly different from that of the controls. Significantly higher levels of hsp70 (c) were present in mild and severely rejecting allografts compared with controls and nonrejecting isografts. In the rat model of heterotopic cardiac transplantation, high levels of hsp70 (i) in the native hearts of the allograft and isograft recipients suggest a transplant-related, cardiac-specific stress process, not previously described. Heat shock protein 70 (c) expression is significantly increased during early and late allograft rejection and may serve as an indicator of transplant rejection.

Receptors that induce erythroid differentiation of Ba/F3 cells: structural requirements and effect on STAT5 binding

Ectopic expression of the erythropoietin receptor (EpoR) in the interleukin-3 (IL-3)-dependent cell line Ba/F3 results in growth and partial erythroid differentiation in Epo. In contrast, introduction and activation of the interleukin-5 receptor (IL-5R) or of the granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR) results in proliferation only. As this effect is specific to the EpoR, the role of its extracellular or cytoplasmic domain in differentiation was tested after construction of two chimeric receptors. One receptor contained the extracellular domain of EpoR fused to the endodomain of IL-3R beta-chain (E/beta), while the other contained the EpoR cytoplasmic region fused to the extracellular domain of GM-CSFR alpha-chain (GMER). Surprisingly, both receptors induced differentiation ruling out a strict specificity of the extracellular or cytoplasmic region of EpoR in this process. Instead the ability to signal differentiation correlated with structural features shared by the EpoR, GMER, and E/beta receptors. Dimerization of all three receptors results in the pairing of two signal transducing chains in the cytoplasm, in contrast to the mitogenic receptors IL-3R, IL-5R, GM-CSFR, which assemble as alphabeta heterodimers. Two new chimeric receptors that fulfilled the structural requirement exemplified by EpoR, but lacked any part of EpoR, were designed to consolidate this model. They consisted of the ectodomains of the GMR-alpha and IL-5R alpha, respectively, fused to the endodomain of IL-3R beta-chain. Both receptors were as effective as EpoR in signaling differentiation in response to their cognate ligand. Another property of receptors fulfilling these structural requirements is that they cause a marked delay in signal transducers and activators of transcription 5 (STAT5) activation on ligand stimulation. Taken together our studies show that structural assembly of receptors dictates their potential to signal erythroid differentiation in Ba/F3 cells, that differentiation can take place in the absence of Epo and that a delay in STAT5 activation is highly predictive of this process.

Tradeoff of semantic relatedness and degree of overlearning: differential effects on metamemory and on long-term retention

We investigated people's recall and recognition of, and Judgments of Learning (JOLs) and Feelings of Knowing (FOKs) about: (a) pairs of related words that were learned to a criterion of two correct recalls (criterion-learned/related) versus (b) pairs of unrelated words that were learned to a criterion of eight correct recalls (overlearned/unrelated). Recall, FOK on unrecalled targets, and recognition were tested at either (between-subjects variable) two or six weeks after learning. In Experiment 1, subjects JOLs were greater in magnitude for criterion-learned/related items than for overlearned/unrelated items, and they predicted that recall would be the same after a 2-week retention interval as after a 6-week retention interval (between-subjects prediction). In contrast, however, subsequent recall was greater on the 2-week retention test than on the 6-week retention test and was greater for the overlearned/unrelated items than for the criterion-learned/related items; also, subjects' FOKs (and recognition performance) were greater in magnitude for the overlearned/unrelated items than for the criterion-learned/related items. Experiment 2 revealed that the overweighting of the importance of relatedness disappears from JOLs when those JOLs occur one day after the acquisition session. These findings imply that the information tracked by metacognitive monitoring judgments is different for JOLs than for FOKs, with the JOLs (relative to FOKs) based more on semantic relatedness and less on the degree of learning during acquisition. Also, subjects' JOLs are not particularly good at accurately forecasting their eventual level of recall on long-term retention tests that occur several weeks after acquisition.

The TEL/platelet-derived growth factor beta receptor (PDGF beta R) fusion in chronic myelomonocytic leukemia is a transforming protein that self-associates and activates PDGF beta R kinase-dependent signaling pathways

The TEL/PDGF beta R fusion protein is the product of the t(5;12) translocation in patients with chronic myelomonocytic leukemia. The TEL/PDGF beta R is an unusual fusion of a putative transcription factor, TEL, to a receptor tyrosine kinase. The translocation fuses the amino terminus of TEL, containing the helix-loop-helix (HLH) domain, to the transmembrane and cytoplasmic domain of the PDGF beta R. We hypothesized that TEL/PDGF beta R self-association, mediated by the HLH domain of TEL, would lead to constitutive activation of the PDGF beta R tyrosine kinase domain and cellular transformation. Analysis of in vitro-translated TEL/ PDGF beta R confirmed that the protein self-associated and that self-association was abrogated by deletion of 51 aa within the TEL HLH domain. In vivo, TEL/PDGF beta R was detected as a 100-kDa protein that was constitutively phosphorylated on tyrosine and transformed the murine hematopoietic cell line Ba/F3 to interleukin 3 growth factor independence. Transformation of Ba/F3 cells required the HLH domain of TEL and the kinase activity of the PDGF beta R portion of the fusion protein. Immunoblotting demonstrated that TEL/PDGF beta R associated with multiple signaling molecules known to associate with the activated PDGF beta R, including phospholipase C gamma 1, SHP2, and phosphoinositol-3-kinase. TEL/PDGF beta R is a novel transforming protein that self-associates and activates PDGF beta R-dependent signaling pathways. Oligomerization of TEL/PDGF beta R that is dependent on the TEL HLH domain provides further evidence that the HLH domain, highly conserved among ETS family members, is a self-association motif.

Association of cocaine and methamphetamine use with giant gastroduodenal ulcers

OBJECTIVES

Giant gastric and duodenal ulcers (>2-3 cm in greatest dimension) are reported to have higher rates of complication and mortality and to be associated with increasing age, renal failure, and use of nonsteroidal antiinflammatory drugs (NSAIDs). This study investigated the outcome and associations of gastric and duodenal ulcers >2.5 cm compared to ulcers of lesser size.

METHODS

Records from all patients with gastric and duodenal ulcers >0.5 cm diagnosed by upper endoscopy between January 1994 and September 1995 were studied for evidence of concurrent use of aspirin, NSAIDs, methamphetamine, and cocaine, as well as for transfusion requirements, length of hospital stay, mortality, surgery, rebleeding, Helicobacter pylori infection, and malignancy.

RESULTS

A logistic regression analysis of the 220 patients identified revealed that recent methamphetamine and/or cocaine use was significantly predictive of giant ulcer formation (p = 0.0002) with an odds ratio of 9.66. Also significant was younger age (p = 0.026) and aspirin or NSAID use (p = 0.046). H. pylori infection was significant only for giant gastric ulcers (p = 0.031). Ulcer size did not predict mortality, rate of rebleeding, requirement for surgery, transfusion requirements, or length of hospital stay. However, giant gastric ulcers were significantly more likely to be malignant (p = 0.002).

CONCLUSIONS

Giant gastric and duodenal ulcers were strongly associated with stimulant abuse. They were also associated with younger age and use of aspirin or NSAIDs. Additionally, giant gastric ulcers were associated with malignancy and H. pylori infection. Ulcer size did not predict rate of complications or outcome.