Acute inflammation with induction of anaphylatoxin C5a and terminal complement complex C5b-9 associated with multiple intra-articular injections of hylan G-F 20: a case report

OBJECTIVE

The purpose of this case report was to investigate local immune mechanisms present during an acute inflammatory flare initiated by viscosupplementation with hylan G-F 20 in a patient with osteoarthritis (OA) and past meniscectomy.

EXPERIMENTAL DESIGN

A patient with a history of bilateral OA and partial left knee meniscectomy, who had received three injections of hylan G-F 20, was diagnosed with an acute flare reaction in the left knee. Her chart was evaluated for clinical, radiological, and laboratory findings and for clinical follow-up. Histopathological synovial examination and real-time polymerase chain reaction (RT-PCR) for genes with major roles in local inflammation and enzyme-linked immunosorbent assays (ELISAs) for markers of complement activation and cytokines were performed. To study the impact of the inflammatory and immune features we compared the case patient with groups of three representative OA and three rheumatoid arthritis (RA) patients.

RESULTS

The patient exhibited evidence of highly increased acute phase reactant C-reactive protein (CRP) in the blood. The pathological examination of the synovial membrane identified abundant fibrinous exudate with numerous particles of hyaluronan surrounded by a dense infiltrate of neutrophils and eosinophils. The synovium had moderate hypertrophy and sclerosis as well as an inflammatory infiltrate predominantly composed of T lymphocytes and macrophages with scattered perivascular eosinophils and neutrophils. Immunoperoxidase staining identified numerous deposits of C5b-9 in the fibrinous exudates and the synovial membrane of the patient. Similar findings were observed in the RA patients, whereas deposits were rare in OA synovial samples. In addition, both anaphylatoxin C5a and the terminal complement complex C5b-9 were present at high levels, comparable to those in RA patients. The levels of mRNA for interleukin-1 beta (IL-1β), IL-6, and the neutrophil marker myeloperoxidase (MPO) were markedly increased compared to those in the RA and OA patients.

CONCLUSIONS

This present study is indicative of a pseudo-septic acute inflammatory reaction in response to local accumulation of hylan G-F 20 with the activation of complement and local invasion of pro-inflammatory cells.

The spectrin cytoskeleton influences the surface expression and activation of human transient receptor potential channel 4 channels

Despite over a decade of research, only recently have the mechanisms governing transient receptor potential channel (TRPC) channel function begun to emerge, with an essential role for accessory proteins in this process. We previously identified a tyrosine phosphorylation event as critical in the plasma membrane translocation and activation of hTRPC4 channels following epidermal growth factor (EGF) receptor activation. To further characterize the signaling events underlying this process, a yeast-two hybrid screen was performed on the C terminus of hTRPC4. The intracellular C-terminal region from proline 686 to leucine 977 was used to screen a human brain cDNA library. Two members of the spectrin family, alphaII- and betaV-spectrin, were identified as binding partners. The interaction of hTRPC4 with alphaII-spectrin and betaV-spectrin was confirmed by glutathione S-transferase pulldown and co-immunoprecipitation experiments. Deletion analysis identified amino acids 730-758 of hTRPC4 as critical for the interaction with this region located within a coiled-coil domain, juxtaposing the Ca(2+)/calmodulin- and IP(3)R-binding region (CIRB domain). This region is deleted in the proposed deltahTRPC4 splice variant form, which failed to undergo both EGF-induced membrane insertion and activation, providing a genetic mechanism for regulating channel activity. We also demonstrate that the exocytotic insertion and activation of hTRPC4 following EGF application is accompanied by dissociation from alphaII-spectrin. Furthermore, depletion of alphaII-spectrin by small interference RNA reduces the basal surface expression of alphahTRPC4 and prevents the enhanced membrane insertion in response to EGF application. Importantly, depletion of alphaII-spectrin did not affect the expression of the delta variant. Taken together, these results demonstrate that a direct interaction between hTRPC4 and the spectrin cytoskeleton is involved in the regulation of hTRPC4 surface expression and activation.

Befriending patients with medication-resistant schizophrenia: can psychotic symptoms predict treatment response?

OBJECTIVES

Supportive interventions are used in schizophrenia, but little research has been conducted into whether any baseline variable predicts treatment response. The aim of this study was to establish if baseline delusions or hallucinations are associated with changes in overall symptoms in patients who received a befriending intervention.

DESIGN

The sample consisted of 44 patients with schizophrenia. These patients comprised the befriending arm of a multicentre randomized controlled trial which compared the efficacy of using CBT against befriending as an adjunct to routine care for patients with medication-resistant schizophrenia.

METHODS

Scores for auditory hallucinations and delusions relating to persecution or control were entered into two regression models. The dependent variables were change in overall symptoms (1) between baseline and end of the intervention, and (2) between baseline and 9 months post-intervention.

RESULTS

Baseline delusions predicted a good response and auditory hallucinations predicted a poor response at 9 months.

CONCLUSIONS

Baseline psychotic symptoms strongly predicted outcome in this sample. The finding that hallucinations predicted a poor outcome is consistent with previous research. These results may help to determine which patients would benefit from supportive interventions.

Epidermal Growth Factor Induces Tyrosine Phosphorylation, Membrane Insertion, and Activation of Transient Receptor Potential Channel 4

Various members of the canonical family of transient receptor potential channels (TRPCs) exhibit increased cation influx following receptor stimulation or Ca(2+) store depletion. Tyrosine phosphorylation of TRP family members also results in increased channel activity; however, the link between the two events is unclear. We report that two tyrosine residues in the C terminus of human TRPC4 (hTRPC4), Tyr-959 and Tyr-972, are phosphorylated following epidermal growth factor (EGF) receptor stimulation of COS-7 cells. This phosphorylation was mediated by Src family tyrosine kinases (STKs), with Fyn appearing to be the dominant kinase. In addition, EGF receptor stimulation induced the exocytotic insertion of hTRPC4 into the plasma membrane dependent on the activity of STKs and was accompanied by a phosphorylation-dependent increase in the association of hTRPC4 with Na(+)/H(+) exchanger regulatory factor. Furthermore, this translocation and association was defective upon mutation of Tyr-959 and Tyr-972 to phenylalanine. Significantly, inhibition of STKs was concomitant with a reduction in Ca(2+) influx in both native COS-7 cells and hTRPC4-expressing HEK293 cells, with cells expressing the Y959F/Y972F mutant exhibiting a reduced EGF response. These findings represent the first demonstration of a mechanism for phosphorylation to modulate TRPC channel function.

The LFA-1-associated molecule PTA-1 (CD226) on T cells forms a dynamic molecular complex with protein 4.1G and human discs large

Clustering of the T cell integrin, LFA-1, at specialized regions of intercellular contact initiates integrin-mediated adhesion and downstream signaling, events that are necessary for a successful immunological response. But how clustering is achieved and sustained is not known. Here we establish that an LFA-1-associated molecule, PTA-1, is localized to membrane rafts and binds the carboxyl-terminal domain of isoforms of the actin-binding protein 4.1G. Protein 4.1 is known to associate with the membrane-associated guanylate kinase homologue, human discs large. We show that the carboxyl-terminal peptide of PTA-1 also can bind human discs large and that the presence or absence of this peptide greatly influences binding between PTA-1 and different isoforms of 4.1G. T cell stimulation with phorbol ester or PTA-1 cross-linking induces PTA-1 and 4.1G to associate tightly with the cytoskeleton, and the PTA-1 from such activated cells now can bind to the amino-terminal region of 4.1G. We propose that these dynamic associations provide the structural basis for a regulated molecular adhesive complex that serves to cluster and transport LFA-1 and associated molecules.

Recent advances in solventless organic reactions: towards benign synthesis with remarkable versatility

A paradigm shift away from using solvents in organic synthesis as solventless reactions can lead to improved outcomes, and more benign synthetic procedures, in for example aldol condensation reactions, sequential aldol and Michael addition reactions en route to Kröhnke type pyridines, reactions leading to 3-carboxycoumarins, benzylidenes, 4-aryl-1,4-dihydropyridines and 2-aryl-1,2,3,4-tetrahydroquinazolines, and oligomerisation reactions for the synthesis of cavitands; kinetic considerations for the reaction of two solids can only be explained if a eutectic melt is formed during the reaction.

Understanding solid/solid organic reactions

The concept of an organic reaction between two macroscopic solid particles is investigated. Thus, we study several reactions that have been recently reported to proceed "in the solid phase" and clearly show that, in most cases, grinding the two solid reactants together results in the formation of a liquid phase. This is true both for catalytic transformations (e.g., aldol condensations and oligomerization of benzylic compounds) and for noncatalytic reactions (Baeyer-Villiger oxidations, oxidative coupling of naphthols using iron chloride, condensation of amines and aldehydes to form azomethines, homo-etherification of benzylic alcohols using p-toluenesulfonic acid, and nuclear aromatic bromination with NBS). This liquefaction implies the existence of a eutectic mixture with T(fusion) below ambient temperature (although both reagents have higher than ambient melting points). In cases where heating is required, it is again clear that a phase change (from solid to liquid) occurs, explaining the observed reaction kinetics. On the basis of 19 experimental examples, we discuss the possibility of solid-phase organic reactions and the implications of these findings to the reaction between two solid reagents. A general description of such reactive systems is proposed, based on a consideration of the potential for eutectic (or peritectic) formation between the constituents of the liquid phases that arise during the process of mechanical mixing of the solid reagents and products.

Effects of water salinity on acid-base balance in decapod crustaceans

Extracellular acid-base balance in decapod crustaceans is influenced by water salinity, although the nature of this relationship is unclear. In euryhaline crabs, a decrease in salinity results in a metabolic alkalosis in the haemolymph and an increase in salinity results in a metabolic acidosis. Alterations in acid-base status by external changes in salinity are thought to be secondary to the adjustments required for ionic and osmotic regulation. In the present study, acid-base adjustments in the haemolymph of Eriocheir sinensis after transfer to 30 % sea water accompanied alterations in muscle pH and [HCO(3)(−)], as an initial acidosis coincided with an alkalosis in the leg muscle. By 48 h transfer, haemolymph pH increased as muscle pH and HCO(3)(−) declined. Haemolymph [Cl(−)] decreased significantly 3 h after transfer to a new steady state but haemolymph [Na(+)] and muscle [Na(+)] and [Cl(−)] remained unchanged. Muscle free amino acid concentration increased twofold 6 h after transfer, followed by a 2.5-fold increase in the haemolymph after 24 h. In contrast, 30 % sea water had no effect on haemolymph acid-base adjustments in the osmoconforming crab, Necora puber, which lacks ion and osmo-regulatory mechansims. Collectively these observations support the view that salinity-induced alterations in acid-base status are caused by adjustments consistent with cell volume regulation.

Working memory capacity and strategy use

In this study, we examine the role of strategy use in working memory (WM) tasks by providing short-term memory (STM) task strategy training to participants. In Experiment 1, the participants received four sessions of training to use a story-formation (i.e., chaining) strategy. There were substantial improvements from pretest to posttest (after training) in terms of both STM and WM task performance. Experiment 2 demonstrated that WM task improvement did not occur for control participants, who were given the same amount of practice but were not provided with strategy instructions. An assessment of participants' strategy use on the STM task before training indicated that more strategic participants displayed better WM task performance and better verbal skills. These results support our hypothesis that strategy use influences performance on WM tasks.

A randomized controlled trial of cognitive-behavioral therapy for persistent symptoms in schizophrenia resistant to medication

BACKGROUND

Research evidence supports the efficacy of cognitive-behavioral therapy in the treatment of drug-refractory positive symptoms of schizophrenia. Although the cumulative evidence is strong, early controlled trials showed methodological limitations.

METHODS

A randomized controlled design was used to compare the efficacy of manualized cognitive-behavioral therapy developed particularly for schizophrenia with that of a nonspecific befriending control intervention. Both interventions were delivered by 2 experienced nurses who received regular supervision. Patients were assessed by blind raters at baseline, after treatment (lasting up to 9 months), and at a 9-month follow-up evaluation. Patients continued to receive routine care throughout the study. An assessor blind to the patients' treatment groups rated the technical quality of audiotaped sessions chosen at random. Analysis was by intention to treat.

RESULTS

Ninety patients received a mean of 19 individual treatment sessions over 9 months, with no significant between-group differences in treatment duration. Both interventions resulted in significant reductions in positive and negative symptoms and depression. At the 9-month follow-up evaluation, patients who had received cognitive therapy continued to improve, while those in the befriending group did not. These results were not attributable to changes in prescribed medication.

CONCLUSION

Cognitive-behavioral therapy is effective in treating negative as well as positive symptoms in schizophrenia resistant to standard antipsychotic drugs, with its efficacy sustained over 9 months of follow-up.

Violence as a public health emergency

Violence threatens or denies not only the health of those who are directly affected but diminishes the whole human process. Neither the violent acts themselves, nor the repercussions of these tragedies, are limited to one geographic or social setting, and it is not just the frequency of violent actions that threatens the health of the nation. It is the ripple effect that occurs from each of these incidents that affects everyone. This article discusses the problem of national violence in the United States and examines preventive programs.

A community medicine project involving an educational session in sexually transmitted diseases for high school students

The University of South Dakota School of Medicine requires that students undertake a Community Medicine project of their choice as part of the Family Medicine course in the third year of medical school. One of these projects consisted of a presentation given to a high school class in Sioux Falls, South Dakota, on sexually transmitted diseases. The effectiveness of the presentation in increasing the students' knowledge on this subject was measured by a pretest and posttest multiple choice examination. The students' knowledge was clearly increased by the presentation.

TLiSA1 (PTA1) activation antigen implicated in T cell differentiation and platelet activation is a member of the immunoglobulin superfamily exhibiting distinctive regulation of expression

T lineage-specific activation antigen 1 (TLiSA1) antigen was initially described as a T lineage-specific activation antigen involved in the differentiation of human cytotoxic T cells. Subsequently, the antigen was identified on platelets and was shown to be involved in platelet activation, hence it was renamed platelet and T cell antigen 1 (PTA1), although identity between the two antigens was not established. In the present study we have cloned the cDNA encoding TLiSA1 from Jurkat cells and show it to be a novel member of the immunoglobulin superfamily with the unusual structure of two V domains only. Identity between TLiSA1 and platelet PTA1 is established by immunological criteria, by internal peptide sequences obtained from the purified platelet glycoprotein and by sequencing the platelet transcript after reverse transcriptase-polymerase chain reaction. In Jurkat cells, TLiSA1/PTA1 mRNA and surface protein expression is greatly stimulated by treatment of the cells with phorbol ester, but the T cell proliferative signal of phorbol ester and ionophore combined greatly reduces or abrogates this response, and this suppressive effect of the ionophore is not reversed by incorporating FK506 to inhibit calcineurin. Together with the known signaling role of PTA1, these data substantiate the notion that this molecule is implicated in T cell differentiation, perhaps by engagement of an adhesive ligand.

Complete genome sequence of the methanogenic archaeon, Methanococcus jannaschii

The complete 1.66-megabase pair genome sequence of an autotrophic archaeon, Methanococcus jannaschii, and its 58- and 16-kilobase pair extrachromosomal elements have been determined by whole-genome random sequencing. A total of 1738 predicted protein-coding genes were identified; however, only a minority of these (38 percent) could be assigned a putative cellular role with high confidence. Although the majority of genes related to energy production, cell division, and metabolism in M. jannaschii are most similar to those found in Bacteria, most of the genes involved in transcription, translation, and replication in M. jannaschii are more similar to those found in Eukaryotes.

Simplification of emergency department discharge instructions improves patient comprehension

STUDY OBJECTIVE

Emergency department patients have been shown to have difficulty understanding written discharge instructions. We attempted to determine whether improvements in comprehension can be achieved by simplification of available materials.

DESIGN

We have previously tested patient understanding of standard discharge instructions. For this study, we simplified the standard instructions. Patients were given one of two simplified instruction sets. After reading the instructions, each patient was asked to answer five specific written questions about them. Results were compared with those from the original study.

SETTING

ED of a large inner-city university hospital.

PARTICIPANTS

Four hundred twenty-three adult ED patients who presented on randomly selected days.

RESULTS

The current and original groups were well matched for demographic variables. Each subject's responses were analyzed for overall success and for success with individual questions. The mean score for the current group was significantly improved over that of the original group. A trend toward improvement was demonstrated in all demographic groups with use of the simplified instructions.

CONCLUSION

Simplified written materials may help patients who do not understand current standard materials. Health care providers should simplify written materials to make them understandable to the greatest number of patients.

Ophthalmologic procedures

Step-by-step instructions for the most common and difficult ophthalmologic procedures that are performed in an emergency department. Foreign body removal, including rust rings, is explained with an emphasis on limiting further injury to the corneal epithelium and stroma. Patching, irrigation, contact lens removal and corneal culture techniques are explained. Three methods of assessing intraocular pressure are described.

Effectiveness of transnasal butorphanol for the treatment of musculoskeletal pain

A prospective, open-label study of the effectiveness of transnasal butorphanol in the treatment of pain resulting from musculoskeletal injuries. Twenty-eight patients with strains (n = 20), fractures (n = 6), contusions (n = 1), and stab wounds (n = 1) were included. All patients were examined by an attending level emergency medicine physician and deemed to have pain severe enough to warrant parenteral narcotic analgesia. All patients received an initial 1-mg dose of transnasal butorphanol. Subsequent dosing was flexible depending on response to the initial dose. All patients received pain relief from transnasal butorphanol, and only one requested alternative analgesic medication. Fifty-seven percent (n = 16) of patients noticed at least a little relief of pain within 5 minutes of administration and 93% (n = 26) received at least a little relief within 15 minutes. Seventy-one percent of the patients received a 50% reduction of pain within 60 minutes. No serious side effects were noted, but drowsiness occurred in 82% (n = 23) and dizziness in 54% (n = 15) of the patients. One patient discontinued participation in the study because of nausea. In this limited trial transnasal butorphanol proved to be a rapidly effective opioid analgesic. Further controlled studies comparing transnasal butorphanol with standard parenteral narcotics are needed.

Phorbol ester-induced transcription of an immediate-early response gene by human T cells is inhibited by co-treatment with calcium ionophore

Human T cells require two discrete signals to initiate their proliferation. In Jurkat T cells the first signal can be provided by the phorbol ester TPA and the second by the calcium ionophore A23187. We have isolated a cDNA from Jurkat T cells representing mRNA induced by TPA but inhibited by simultaneous treatment of the cells with antibody, lectin, or A23187. Sequencing revealed identity of the Jurkat clone to a cDNA, termed ETR101, recently isolated from HL60 promyelocytic leukaemia cells and shown to be an immediate early gene expressed upon TPA stimulation of these cells [Shimizu et al.: J Biol Chem 266:12157, 1991]. The gene is also induced very rapidly upon TPA treatment of Jurkat cells and is superinduced by co-treatment with cycloheximide. The predicted amino acid sequence encoded by ETR101 has weak homology to JunB and JunD, therefore it is of some interest that these three genes share the chromosomal localization, 19p13.2. The divergent effects of TPA treatment upon cell proliferation and differentiation in different circumstances allow some speculation about a possible role for the ETR101 gene product upon cellular differentiation.

Splatter during jet irrigation cleansing of a wound model: a comparison of three inexpensive devices

STUDY OBJECTIVE

Pressurized jet irrigation is commonly used to cleanse traumatic wounds but results in splatter of blood, a biohazard. Three inexpensive irrigation devices were compared to assess the degree of splatter produced: a 1.25-in. 18-gauge angiocath, an Irrijet Irrigation System with a 12.7-cm splash shield, and a Zerowet Splashield held directly against the wound (Zerowet-C) and held 4 to 10 cm from the wound, an incorrect technique (Zerowet-I).

DESIGN

A standard laceration was created in pieces of beef. This wound model was placed 1 m from the floor. Paper grid sheets were placed on the irrigator's face and chest. Six grid sheets were suspended at the 9:00, 12:00, and 3:00 positions 1 m from the wound model and 1 and 1.5 m from the floor to simulate exposure to nearby individuals. Two grid sheets were placed flat on the floor, at the 10:30 and 1:30 positions, 1 m from the base of the wound model stand. The study area was contained in a 3 x 2 x 2 m plastic sheet enclosure to prevent air drafts.

INTERVENTION

Ten irrigations were performed with the angiocath, Irrijet, Zerowet-I, and Zerowet-C. Each run used 200 mL methylene blue solution delivered with a 50-mL syringe by one-hand pressure. The methylene blue splatter on each of the grids was counted by size (diameter, less than 1 mm, more than 1 mm and less than 5 mm, more than 5 mm and less than 10 mm, and more than 10 mm).

RESULTS

There was significantly less splatter onto the irrigator's face and chest with Irrijet, Zerowet-I, and Zerowet-C. No facial splatter occurred with Zerowet-C. There was significantly less splatter at the 9:00 and 12:00 positions at both heights, and on the floor with Irrijet, Zerowet-I, and Zerowet-C. Less significant splatter difference was noted at the 3:00 position.

CONCLUSION

Irrijet, Zerowet-I, and Zerowet-C were superior to the angiocath in preventing splatter during this wound model irrigation. The correct use of Zerowet (Zerowet-C) was particularly effective in preventing splatter onto the irrigator's face.

Angioedema in the emergency department: the impact of angiotensin-converting enzyme inhibitors

Angiotensin-converting enzyme (ACE) inhibitors have been reported to cause angioedema. The purpose of this study was to establish what proportion of patients who present to the emergency department (ED) with angioedema were concomitantly taking any of the ACE inhibitors and to show how this group differed in presentation and response to treatment from the larger population of patients with non-ACE inhibitor-related angioedema. An 8-year retrospective chart review of all patients with the diagnosis of angioedema observed from January 1, 1984 to December 31, 1991 was undertaken in the ED of an urban teaching hospital. Forty-nine patients ranging from 12 to 88 years of age with symptoms and physical examination that was consistent with the diagnosis of angioedema were entered onto the study. Twelve cases of ACE inhibitor-related angioedema were identified, all occurring in the last 4 years of the review, and when compared with the non-ACE inhibitor-related group were older (mean age, 63.3 vs 43.0 years), had less of an allergic history (0% vs 49%; P = .013), but demonstrated the same severity of symptoms and response to medical therapy. No case required an artificial or surgical airway. ACE inhibitor related angioedema is becoming a common type of angioedema observed in this ED. These patients are older and free of other allergic disease and respond well to traditional therapy.

Functional illiteracy among emergency department patients: a preliminary study

STUDY OBJECTIVES

To determine the ability of emergency department patients to understand common written discharge instructions and the level of reading difficulty of standard discharge instructions.

DESIGN

The study was performed in two parts. In part 1, subjects were asked to read one set of standard written discharge instructions. Then, with the instructions to refer to, subjects were asked to answer five questions about the instructions. A subject's level of success was correlated with age, sex, and highest level of education. In part 2, 47 sets of standard written discharge instructions from six different EDs were computer analyzed using five commonly used readability formulas. Results were reported as grade levels.

SETTING

The ED of a large inner-city university hospital.

TYPE OF PARTICIPANTS

The subjects for part 1 were 400 adult ED patients who presented on randomly selected days.

MEASUREMENTS AND MAIN RESULTS

Part 1: A significant proportion of patients failed to answer correctly at least four of five questions. Patients educated beyond high school demonstrated higher levels of success than did those with less education. A trend was noted for younger subjects to perform better than older subjects. The answers to the three most frequently missed questions were contained within areas of difficult sentence structure or long paragraphs containing large amounts of information. Part 2: The average grade level required to understand instruction sheets ranged from 6.0 to 13.4. More difficult instruction sheets tended to contain numerous multi-syllabic words, long sentences, and difficult sentence structure.

CONCLUSION

A significant proportion of ED patients have a demonstrable inability to understand common written instructions. ED instruction sheets are written at a level of difficulty that is out of the readable range for many patients. Health care providers should strive to simplify written materials and to develop new methods for instructing those for whom current written materials have no meaning.

Clostridial myonecrosis resulting from subcutaneous epinephrine suspension injection

A 32-year-old asthmatic man developed a life-threatening Clostridium perfringens infection after subcutaneous epinephrine suspension injection. Extensive surgical debridement, including forequarter amputation, hyperbaric oxygen therapy, and appropriate antibiotics were used as life-saving measures. The patient made a fair functional recovery. We could find no previously reported cases of gas gangrene following subcutaneous injection in otherwise healthy individuals. The pathogenesis and treatment of this infection are discussed.

Individual embryonic fibroblasts express multiple beta chains in association with the alpha v integrin subunit. Loss of beta 3 expression with cell confluence

The alpha chain of the vitronectin receptor, alpha v, has been found in association with the integrin subunits beta 1, beta 3, or beta 5 on different cell types. We show here that cultured embryonic fibroblasts simultaneously display alpha v beta 3, alpha v beta 1, and alpha v in association with two other beta subunits, one of which is probably beta 5. Polymerase chain reaction analysis of single cells isolated by micromanipulation identified mRNA for alpha v, beta 1, beta 3, and beta 5 in six of eight clones. Immunoprecipitation of iodinated cell surface proteins with a monoclonal antibody to alpha v indicated that the relative proportions of the different beta chains in association with alpha v varied, particularly between two different cell lines. The cytokines platelet-derived growth factor, transforming growth factor beta 1, and tumor necrosis factor alpha did not appear to alter this ratio although tumor necrosis factor alpha increased the surface expression of the alpha v-associated integrins; but overnight culture in basic fibroblast growth factor caused a lower expression of alpha v beta 1 and alpha v beta 5 with no reduction in alpha v beta 3 expression. When the cell cultures were grown to complete confluence, surface expression of beta 3 was abolished, and the expression of an unknown beta chain (beta u) became more prominent. This effect was not overcome by culturing confluent cells with basic fibroblast growth factor. Affinity column chromatography showed that alpha v beta 5 bound to vitronectin but alpha v beta 1 did not, whereas alpha v beta 1 but not alpha v beta 5 bound to fibronectin. These results suggest that, on individual cells, the beta subunits found in association with alpha v may vary according to the proliferative capacity of the cell and that the promiscuous beta 3 subunit is progressively replaced by beta subunits of individual ligand specificity.

Characterization of a novel membrane glycoprotein involved in platelet activation

When platelets bind certain specific ligands they are induced to secrete the contents of their cytoplasmic granules and to aggregate. Studies of the molecular events accompanying this vital physiological response have led to a greater understanding of cell activation in general since the pathways involved are common to a number of cell types. By contrast most of the information about the cell surface molecules that initiate signal transduction has emerged from work on T lymphocyte activation, a process essential to the initiation of the immune response. We have described an activation antigen on T lymphocytes that is involved in the differentiation of these cells. In the present report it is demonstrated that the antigen is expressed on the platelet membrane with about 1,200 copies/platelet. A monoclonal antibody detecting this antigen stimulates platelet secretion and aggregation with a half-maximal response at approximately 10(-8) M. Characterization of the antigen, termed PTA1, reveals a glycoprotein of Mr 67,000 showing extensive N-linked carbohydrate, much of which appears to be heavily sialated. The amino-terminal sequence of PTA1, EEVLWHTSVPFAEXMSLEXVYPSM, indicates that the protein has not previously been characterized. Preliminary investigation of the mechanism by which PTA1 mediates platelet activation suggests involvement of protein kinase C and the 47-kDa protein of platelets is rapidly phosphorylated upon antibody-mediated activation. During this process PTA1 is also phosphorylated, as it is following platelet activation by the other agonists, collagen, thrombin, and 12-O-tetradecanoylphorbol 13-acetate. These results provide the first example of a cell surface glycoprotein that is directly involved in both platelet and T lymphocyte activation.

Relationships between fertility, peak milk yields and lactational persistency in dairy cows

Peak milk yield, lactational persistency and conception rates were studied using 5928 lactation records of high milk-producing cows at three California dairies. Log-linear analysis was used to study relationships between peak milk yield, lactational persistency, dairy of origin, lactation number and conception rates in 3850 completed lactations. Cows with peak milk yields greater than the median (38.2 kg milk per day) were less likely to have conceived in one or two breedings than cows with peak milk yields lower than or equal to the median. Cows with a higher than median (0.755) lactational persistency were less likely to have conceived in one or two breedings than cows with a lactational persistency lower than or equal to the median. Dairy of origin had a significant effect on the probability of conceiving in one or two breedings. Cows in the first lactation were more likely than those in subsequent lactations to conceive in one or two breedings. This retrospective study demonstrated that subfertility is associated with high peak lactational yields in high milk-producing California cows.

TGF beta down-regulates TLiSA1 expression and inhibits the differentiation of precursor lymphocytes into CTL and LAK cells

This study analysed the regulatory effects of transforming growth factor beta (TGF beta) on the expression of a 70,000 MW cell surface activation antigen, TLiSA1, involved in the differentiation of cytotoxic T lymphocytes (CTL) and lymphokine-activated killer (LAK) cells from their precursor(s), and also examined the role of TGF beta in the generation of these functional cells. TGF beta was shown to suppress the expression of TLiSA1 and to inhibit, in a dose-dependent manner, the generation of both CTL and LAK cells when present from the beginning of mixed lymphocyte culture; the same inhibitory effect upon the development of cytotoxic effector cells was observed with a monoclonal antibody and with monospecific rabbit antibodies against the TLiSA1 protein. Antibody to TGF beta reversed the inhibitory effect of the cytokine on differentiation and on TLiSA1 expression. Exogenous IL-2 or, to a lesser extent, tumour necrosis factor alpha (TNF alpha) added to mixed lymphocyte cultures (MLC) augmented both TLiSA1 antigen expression and cytotoxic function by the resulting blast cells; the co-addition of TGF beta inhibited both of these cytokine-mediated effects. Similarly, it was shown that phytohaemagglutini (PHA)-induced lymphoblasts up-regulate their surface expression of TLiSA1 and exhibit increased LAK activity in response to IL-2, and TGF beta inhibited both of these events; this IL-2-induced increase in LAK cell function was also inhibited by antibodies to TLiSA1. It is suggested that TLiSA1 antigen expression is intimately linked to the differentiation of cytotoxic effector cells and that such differentiation may be a distinct process from IL-2-induced proliferation, although both events can be regulated by TGF-beta.

BIVALVE HEMOCYANIN: STRUCTURAL, FUNCTIONAL, AND PHYLOGENETIC RELATIONSHIPS

The hemocyanin-like molecule found in the blood of the most primitive bivalves (protobranchs) reversibly binds O₂. Its respiratory properties and its sedimentation behavior are both distinctive. Although its electron-dense image looks like that of the gastropod hemocyanins, its molecular weight differs from those of all other molluscan Hcs and is more consistent with the concept of bivalve hemocyanin as a pair of octopod hemocyanins. Bivalve hemocyanin occurs in the solemyoids as well as the nuculoids, which argues for the integrity of the Protobranchia as a natural taxon. The ancestral bivalve O₂ carrier was previously believed to be a simple intracellular hemoglobin, which is found in the less primitive Pteriomorpha. The most obvious interpretation of the present results, however, is that hemocyanin is the primitive bivalve O₂ cannier and that it was replaced by the red blood cell, which originated at least twice: once in the pteriomorph bivalves and at least once in other taxa.

Centipedal hemocyanin: its structure and its implications for arthropod phylogeny

The oxygen carrier hemocyanin occurs in the blood of Scutigera coleoptrata, a uniramous arthropod, as well as the crustaceans and chelicerates. The native polymer appears to be composed of substructures having the same size and electron-dense image as those of other arthropod hemocyanins but assembled into a unique multiple and arranged in a unique configuration. The simplest explanation of these findings is that the arthropod hemocyanins have a common origin, exemplifying a derived (as opposed to primitive) character shared by each of the three living groups.

QT interval prolongation

The QT interval is a function of ventricular repolarization time and is measured from the onset of the QRS complex to the end of the T wave. The length of this interval is inversely related to heart rate. A prolonged QT interval is most often secondary to the use of Type I antidysrhythmic medications (quinidine, procainamide). It is also associated with phenothiazines, organophosphates, hypocalcemia, liquid protein diets and the congenital long QT syndromes. QT prolongation is associated with a variety of ventricular dysrhythmias, most characteristically Torsades des pointes. Treatment consists of correction of the underlying metabolic disorder or discontinuation of the offending medication.

Actinomyces hordeovulneris, a canine pathogen that produces L-phase variants spontaneously with coincident calcium deposition

The spontaneous production of cell-wall-deficient filaments and protoplasts by a strain of Actinomyces hordeovulneris (UCD 81-332-9) in 10% sucrose L-form media is reported. Multiple mineral deposits were present within the variants at 48 hours. Electron microscopy revealed that these deposits were amorphous, dense, and at the inner face of the cytoplasmic membrane in wall-less protoplasts and also in filaments which had a thin wall of 10 nm. These cell-wall-deficient variants produced L-form colonies when cultured for an additional 48 hours on 10% sucrose-BYE L-form plates. The colonies were composed of only a few filaments and many vesicles which were negative with Dienes' stain. Silver substitution stains of UCD 81-332-9 cells that had been grown in L-form broth for 5 days revealed heavy calcification of all cells including protoplasts. Gram stains of L-form grown cells revealed the presence of long-beaded, infrequently branched gram-positive filaments similar to those observed in clinical specimens. The formation of cell wall-deficient variants with coincident mineralization is believed to be related to the phenomenon of sulfur granule formation in vivo.

Nocardia asteroides recovery from a dog with steroid- and antibiotic-unresponsive idiopathic polyarthritis

This report describes a fatal case of idiopathic polyarthritis in a dog that was partially responsive to vigorous immunosuppressive treatment. Synovial fluids were cultured for L-forms at the following stages of disease: (i) acute arthritic relapse, (ii) incomplete remission, and (iii) death. Nocardia asteroides UCD 1-581 was recovered from the L-form broth culture of the specimen taken during acute relapse, 5 weeks after inoculation, but not at any other stage of disease. Numerous conventional microbiological cultures were unproductive during all phases. Changes occurring in L-form plates included the formation of large irregular mineral deposits and many transferable bodies resembling pseudocolonies. Microscopic examination revealed the presence of many intracellular golden-brown granules and acid-fast bodies in macrophages of the lung and bronchial lymph node tissues. The granules are believed to be the variants embedded in calcium deposits similar to those which developed in the L-form cultures in vitro. Fluorescence of these acid-fast bodies with antibody specific for superoxide dismutase of N. asteroides GUH-2 and labeled anti-immunoglobulin G established their relationship to the isolate. The unrelenting course of disease and the persistence of N. asteroides as an L-form in this animal despite vigorous immunosuppression suggest that this organism plays a direct role in the etiology of this disease.

Immunopathology of natural and experimental lymphomas induced by wild mouse leukemia virus

Naturally occurring lymphomas of Lake Casitas (LC) wild mice, and the lymphomas induced by LC murine leukemia virus (MuLV) in Swiss mice from the National Institutes of Health, displayed remarkably similar gross, microscopic, and functional characteristics. They spared the thymus, arose primarily in the splenic red pulp, became leukemic, and were comprised of stem cells lacking classic T- and B-cell markers. Cytoplasmic and surface immunoglobulin were undetectable in 34 of 35 spontaneous LC lymphomas and in any of ten LC MuLV-induced lymphomas in NIH Swiss mice. Assays for immunoglobulin secretion, complement (C'3) and Fc receptors, Thy 1.1,2 antigens, Ly 1,2 antigens, and erythroid and myeloid markers were negative on all of the spontaneous and experimental lymphomas. Cell lines were derived from five spontaneous lymphomas of LC mice. Three lines were characterized as null cells, one line as B cells, and one line as macrophages. All cell lines were diploid. The wild mouse spontaneous lymphomas, and lymphomas experimentally induced by LC MuLV in laboratory mice, provide a useful model for childhood acute lymphoblastic leukemia and for study of the early steps of B-lymphocyte differentiation.

Natural killer cell activity in a population of leukemia-prone wild mice (Mus musculus)

Natural cell-mediated cytotoxicity against YAC-I targets was measured in splenocytes from leukemia-prone wild mice trapped near Lake Casitas (LC) in southern California. Cytotoxicity was mediated by cells that were non-adherent to nylon wool, non-phagocytic and resistant to thy-1.2 antiserum plus complement. Natural MuLV viremia in LC mice did not impair splenic cytotoxicity against TAC-I target cells, Cells infected with amphotropic and ecotropic MuLV of wild mouse origin were not appreciably lysed by LC splenic effectors. Although variable levels of cytotoxicity were detected against TAC-1 by normal spleen cells, consistently low levels of cytotoxicity against allogenic LC lymphoma, sarcoma and carcinoma targets were found using the same splenocytes. These results indicate that LC mice possess splenocytes with the characteristics of natural killer (NK) cells as defined in inbred mice. The resistance of LC-derived targets to lysis by LC NK cells suggests that NK cells may not be involved in natural tumor immunosurveillance or that the development of spontaneous tumors may involve escape from NK-mediated effector mechanisms.

Acute leukemia following prolonged cytotoxic agent therapy

1. Nine patients in whom acute non-lymphoblastic leukemia (ANLL) developed following prolonged alkylating agent therapy are described. Five of the patients received no radiotherapy. The conditions treated were: Hodgkin's disease (four patients), primary amyloidosis, primary macroglobulinemia, malignant lymphoma, multiple myeloma, and carcinoma of the tonsil. 2. Prior to the advent of chemotherapy, this complication was not observed in large series of patients with lymphoproliferative disorders and multiple myeloma. However, the medical literature now contains at least 125 other detailed reports of ANLL developing after prolonged cytotoxic agent therapy. 3. Multiple myeloma and Hodgkin's disease, both of which commonly have good responses to chemotherapy, predominate as the underlying diseases. However, 35% of the case reports involve patients with other illnesses, including 12 patients who did not have neoplasms. 4. More than half of the patients developing ANLL have received chemotherapy alone without radiotherapy. 5. At least half of the patients developing ANLL experienced long periods of significant cytopenia during therapy, often with documentation of bone marrow dysplasia. 6. The wide variety of drugs associated with this complication suggests that any cytotoxic agent may be leukemogenic. However, alkylating agents overwhelmingly predominate as the class of compounds which are most often associated with terminal ANLL. 7. The vast majority of patients reported in the literature with ANLL complicating underlying malignancies have received cytotoxic drugs for prolonged periods (median 3 1/2 years) and leukemia developed most commonly 3 to 5 years after the diagnosis of the underlying disease. Most of these patients benefited from therapy and survived longer (median 5 years) than historical control of untreated patients. 8. The leukemogenic potential in man of prolonged cytotoxic agents therapy, especially with alkylating agents, seems to be well established. This evidence admonishes against the prolonged use of these drugs in non-fatal disorders. 9. More accurate assessment of risk: benefit ratios awaits the results of prospective controlled studies. The results of these studies could also lead to significant modifications in recommendations for long-term maintenance therapy with cytotoxic agents.

Aplastic anemia associated with type B viral hepatitis

Aplastic anemia is a recognized complication of viral hepatitis, but, to our knowledge, no cases associated with type B hepatitis have been described. We report the case of a patient who developed severe aplastic anemia very early in the course of infection with hepatitis B virus.