Evaluation of Noncommercial Ultrasound Gels for Use in Resource-Limited Settings.

OBJECTIVES: Ultrasound (US) is increasingly used in settings where commercial US gel is unavailable. This study evaluated noncommercial gel recipes compared to commercial gel. METHODS: A search for US gel formulations revealed 6 recipes. Half-strength commercial gel and a modified glucomannan recipe were also tested. Nine gels, including commercial gel, were tested in Liberia and the United States. In each session, 2 physician sonologists evaluated 9 gels on 2 models, obtaining videos from the hepatorenal space with a curvilinear transducer, the cardiac parasternal long view with a phased array transducer, and the left basilic vein with a linear transducer. The sonologists and models, who were blinded to gel identity, made independent quantitative and qualitative gel evaluations comparing the test gel to commercial gel. Two physician sonologists who were blinded to the gel identities and a US operator reviewed the images and rated their quality. An analysis of variance in repeated measures was performed to test for differences in the overall score, real-time quality, and other characteristics. Post hoc pairwise comparisons to commercial gel were performed with a Tukey-Kramer adjustment. Inter- and intra-rater reliability was calculated for the image review. RESULTS: Commercial gel earned a perfect score. Compared to commercial gel, xanthine gum gel scored highest, followed by half-strength commercial gel. Hot concentrated glucomannan and cold glucomannan gel were found to be significantly worse than commercial gel. No significant difference was found between images based on the gel used on the image review. CONCLUSIONS: No significant difference in image quality was found between commercial and noncommercial gels on US image review.

Defective acid hydrolase secretion in RUNX1 haplodeficiency: Evidence for a global platelet secretory defect.

BACKGROUND: RUNX1 haplodeficiency is associated with thrombocytopenia, platelet dysfunction and a predisposition to acute leukaemia. Platelets possess three distinct types of granules and secretory processes involving dense granules (DG), α-granules and vesicles or lysosomes containing acid hydrolases (AH). Dense granules and granule deficiencies have been reported in patients with RUNX1 mutations. Little is known regarding the secretion from AH-containing vesicles. METHODS AND RESULTS: We studied two related patients with a RUNX1 mutation, easy bruising, and mild thrombocytopenia. Platelet aggregation and 14 C serotonin in platelet-rich plasma (PRP) were impaired in response to ADP, epinephrine, collagen and arachidonic acid. Contents of DG (ATP, ADP), α-granules (ß-thromboglobulin) and AH-containing vesicles (ß-glucuronidase, ß-hexosaminidase, α-mannosidase) were normal or minimally decreased. Dense granules secretion on stimulation of gel-filtered platelets with thrombin and divalent ionophore A23187 (4-12 µmol L-1 ) were diminished. ß-thromboglobulin and AH secretion was impaired in response to thrombin or A23187. We studied thromboxane-related pathways. The incorporation of 14 C -arachidonic acid into phospholipids and subsequent arachidonic acid release on thrombin activation was normal. Platelet thromboxane A2 production in whole blood serum and on thrombin stimulation of PRP was normal, suggesting that the defective secretion was not due to impaired thromboxane production. CONCLUSIONS: These studies provide the first evidence in patients with a RUNX1 mutation for a defect in AH (lysosomal) secretion, and for a global defect in secretion involving all three types of platelet granules that is unrelated to a granule content deficiency. They highlight the pleiotropic effects and multiple platelet defects associated with RUNX1 mutations.

Intensive point-of-care ultrasound training with long-term follow-up in a cohort of Rwandan physicians.

OBJECTIVE: We delivered a point-of-care ultrasound training programme in a resource-limited setting in Rwanda, and sought to determine participants' knowledge and skill retention. We also measured trainees' assessment of the usefulness of ultrasound in clinical practice. METHODS: This was a prospective cohort study of 17 Rwandan physicians participating in a point-of-care ultrasound training programme. The follow-up period was 1 year. Participants completed a 10-day ultrasound course, with follow-up training delivered over the subsequent 12 months. Trainee knowledge acquisition and skill retention were assessed via observed structured clinical examinations (OSCEs) administered at six points during the study, and an image-based assessment completed at three points. RESULTS: Trainees reported minimal structured ultrasound education and little confidence using point-of-care ultrasound before the training. Mean scores on the image-based assessment increased from 36.9% (95% CI 32-41.8%) before the initial 10-day training to 74.3% afterwards (95% CI 69.4-79.2; P < 0.001). The mean score on the initial OSCE after the introductory course was 81.7% (95% CI 78-85.4%). The mean OSCE performance at each subsequent evaluation was at least 75%, and the mean OSCE score at the 58-week follow up was 84.9% (95% CI 80.9-88.9%). CONCLUSIONS: Physicians providing acute care in a resource-limited setting demonstrated sustained improvement in their ultrasound knowledge and skill 1 year after completing a clinical ultrasound training programme. They also reported improvements in their ability to provide patient care and in job satisfaction.

Improvement of microbial strain and fermentation process of rapamycin biosynthesis.

The purpose of this investigation is to enhance the production of the immunosuppressant drug rapamycin by subjecting the strain CBS 773.23 to ultraviolet (UV) and N-methyl-N'-nitro-N-nitroso guanidine (NTG) mutations. Among all the mutants tested, MTCC 5681 (NRC-CM03/SH) obtained by NTG mutagenesis of strain CBS 773.72 showed the highest activity, 210 mg/L. The effect of different factors including medium composition, pH, temperature, and intensity of mixing on rapamycin production was studied. Based on the study, the optimal concentrations of soluble starch and dry yeast granules were found to be 50 g/L and 1.5 g/L, respectively. Furthermore, optimal values for pH, temperature, and shaking speed were found to be 6.0, 28°C, and 220 rpm, respectively. The production of rapamycin increased 1.6-fold, to 360 mg/L, in shake-flask culture using the optimal combination of factors observed compared with basal cultivation medium using MTCC 5681 mutant strain.

Tosylate salts of the anticancer drug lapatinib.

Two tosylate salts of an anticancer drug lapatinib, viz. a monotosylate [systematic name: ({5-[4-({3-chloro-4-[(3-fluorophenyl)methoxy]phenyl}amino)quinazolin-6-yl]furan-2-yl}methyl)[2-(methylsulfonyl)ethyl]azanium 4-methylbenzenesulfonate], C29H27ClFN4O4S(+)·C7H7O3S(-), (I), and a ditosylate [systematic name: 4-({3-chloro-4-[(3-fluorophenyl)methoxy]phenyl}amino)-6-]5-({[2-(methylsulfonyl)ethyl]azaniumyl}methyl)furan-2-yl[quinazolin-1-ium bis(4-methylbenzenesulfonate)], C29H28ClFN4O4S(2+)·2C7H7O3S(-), (II), were obtained during crystallization attempts for polymorphism. In both structures, the lapatinib cation is in a distorted U-like conformation and the tosylate anion is clamped between the aniline N atom and methylamine N atom through N-H···O hydrogen bonds, forming an R2(2)(15) ring motif. The 4-anilinoquinazoline ring system is essentially planar in (I), while it is twisted in (II), controlled by an intramolecular C-H···N interaction. In (I), alternating cations and anions are linked by N-H···O hydrogen bonds into C2(2)(6) chains. These chains are linked by cations in a helical manner. The presence of the additional tosylate anion in (II) results in the formation of one-dimensional tapes of fused hydrogen-bonded rings through N-H···O and C-H···O interactions. These studies augment our understanding of the role of nonbonded interactions in the solid state, which is useful for correlation to the physicochemical properties of drug products.

Sorafenib and its tosylate salt: a multikinase inhibitor for treating cancer.

Sorafenib, a drug that targets malignant cancer cells and cuts off the blood supply feeding the tumour, has been crystallized as the free base, 4-(4-{3-[4-chloro-3-(trifluoromethyl)phenyl]ureido}phenoxy)-N-methylpyridine-2-carboxamide, C(21)H(16)ClF(3)N(4)O(3), (I), and as a tosylate salt, 4-(4-{3-[4-chloro-3-(trifluoromethyl)phenyl]ureido}phenoxy)-2-(N-methylcarbamoyl)pyridinium 4-methylbenzenesulfonate, C(21)H(17)ClF(3)N(4)O(3)(+)·C(7)H(7)O(3)S(-), (II). In both structures, the sorafenib molecule is in an extended conformation. The pyridine-2-carboxamide group exhibits a syn conformation of the N atoms in (I), whereas an almost anti orientation is present in (II). In both crystal structures, the two terminal groups, viz. pyridine-2-carboxamide and the trifluorophenyl ring, are oriented differently to the conformations found in enzyme-bound sorafenib. The sorafenib molecules in (I) are linked into zigzag chains by N-H···O hydrogen bonds, whereas in (II) the presence of the additional tosylate anion results in the formation of chains of fused hydrogen-bonded rings. This study reveals the variations in the solid-state conformation of the sorafenib molecule in different crystalline environments.

Response of thickened nerve trunks and skin lesions of leprosy patients to MDT.

This paper indicates the responses of thickened nerve trunks in leprosy patients to MDT. Out of 1625 cases, 557 (34.2%) cases had thickened nerve trunks at the time of registration. From these cases, 175 (31.4%) were randomly selected and re-examined by personal visit about 5 years after RFT. Follow-up showed persistent thickening in 96 (54.8%) cases. Persistence of nerve thickening was higher in MB leprosy. Additional nerve thickening appeared in 8 (4.6%) cases. New disability developed in 6 (3.4%) cases after RFT but these persons did not come for check up voluntarily. Reaction occurred in 6 during follow-up. Both MB and PB considered together thickening continued in as high as 96 (54.8%) compared to persisting skin lesions in 24 (13.7%) cases. Persons with thickened nerve trunks require more counseling to report for check up at the earliest sign of nerve function deficit.

Transfer of disability care of leprosy to the affected persons and the community members.

Bargarh district in the western Orissa had high leprosy burden and LEPRA India supported in control activities. Its main focus was on POD care with community participation. After motivation and capacity building, it transferred the responsibility of POD care to affected persons, family, community partners and GHS staff in 2006. The effectiveness of this approach was evaluated in 2009. With personal contact responses from 112 (17%) persons with disability and 18 stakeholders were obtained. Result shows 98% affected persons are staying with family; 92% are practicing self-care; 92% felt self-care is beneficial; 57% and 36% are using commercial and MCR footwear respectively. Surgical correction of deformity is maintained in 80% of cases. Difficulty in activity and in community participation was experienced in about one third of affected persons the latter is mostly due to self stigma. The facilitators were happy with their beneficiaries.

A simple and effective approach for the treatment of chronic wound infections caused by multiple antibiotic resistant Escherichia coli.

Antimicrobial resistance is a major problem in present-day therapy. Despite the advent of newer antimicrobial agents with a broad spectrum of activity, multiple antibiotic resistant pathogens are difficult to eliminate from infected sites. The present study was carried out to develop an approach, using citric acid as a sole antimicrobial agent, for the treatment of chronic wound infections caused by multiresistant Escherichia coli (MAREC). A total of 34 cases of chronic wound infections yielding MAREC isolates on culture were studied. The antibacterial effect of citric acid against MAREC was evaluated in vitro by broth dilution method. Three percent citric acid gel was applied to each wound once daily until it healed completely. All 34 isolates were inhibited by citric acid with minimum inhibitory concentrations in the range of 1500-2000 microg/ml. Topical application of 3% citric acid to wounds 7-42 times resulted in elimination of MAREC from infected sites and successful healing of wounds in all 34 patients. This treatment modality was simple, reliable, non-toxic and effective. Hence, the use of citric acid for the cost-effective treatment of wound infections caused by MAREC is recommended.

Decreased platelet expression of myosin regulatory light chain polypeptide (MYL9) and other genes with platelet dysfunction and CBFA2/RUNX1 mutation: insights from platelet expression profiling.

We have reported on a patient with thrombocytopenia, impaired platelet aggregation, secretion, phosphorylation of pleckstrin and myosin light chain (MLC), and GPIIb-IIIa activation, associated with a heterozygous mutation in transcription factor CBFA2 (core binding factor A2, RUNX1 or AML1). To obtain insights into the abnormal platelet mechanisms and CBFA2-regulated genes, we performed platelet expression profiling in four control subjects and the patient using the Affymetrix U133 GeneChips. In the patient, 298 probe sets were significantly downregulated at least 2-fold. MLC regulatory polypeptide (MYL9 gene) was decreased approximately 77-fold; this is an important finding because agonist-stimulated MLC phosphorylation is decreased in patient platelets. Genes downregulated > or = 5-fold include those involving calcium binding proteins (CABP5), ion transport (sodium/potassium/Ca exchanger, SLC24A3), cytoskeletal/microtubule proteins (erythrocyte membrane protein band 4.1-like 3, EPB41L3; tropomyosin 1, TPM1; tubulin, alpha 1, TUBA1), signaling proteins (RAB GTPase activating protein 1-like, RABGAP1L; beta3-endonexin, ITGB3 BP) and chemokines (platelet factor 4 variant 1, PF4V1; chemokine CXCL5, CXCL5). These and other downregulated genes are relevant to the patient's platelet defects in function and production. These studies provide the first proof of concept that platelet expression profiling can be applied to obtain insights into the molecular basis of inherited platelet defects.

Dysregulation of PLDN (pallidin) is a mechanism for platelet dense granule deficiency in RUNX1 haplodeficiency.

Essentials Platelet dense granule (DG) deficiency is a major abnormality in RUNX1 haplodeficiency patients. The molecular mechanisms leading to the platelet DG deficiency are unknown. Platelet expression of PLDN (BLOC1S6, pallidin), involved in DG biogenesis, is regulated by RUNX1. Downregulation of PLDN is a mechanism for DG deficiency in RUNX1 haplodeficiency. SUMMARY: Background Inherited RUNX1 haplodeficiency is associated with thrombocytopenia and platelet dysfunction. Dense granule (DG) deficiency has been reported in patients with RUNX1 haplodeficiency, but the molecular mechanisms are unknown. Platelet mRNA expression profiling in a patient previously reported by us with a RUNX1 mutation and platelet dysfunction showed decreased expression of PLDN (BLOC1S6), which encodes pallidin, a subunit of biogenesis of lysosome-related organelles complex-1 (BLOC-1) involved in DG biogenesis. PLDN mutations in the pallid mouse and Hermansky-Pudlak syndrome-9 are associated with platelet DG deficiency. Objectives We postulated that PLDN is a RUNX1 target, and that its decreased expression leads to platelet DG deficiency in RUNX1 haplodeficiency. Results Platelet pallidin and DG levels were decreased in our patient. This was also observed in two siblings from a different family with a RUNX1 mutation. Chromatin immunoprecipitation and electrophoretic mobility shift assays with phorbol ester-treated human erythroleukemia (HEL) cells showed RUNX1 binding to RUNX1 consensus sites in the PLDN1 5' upstream region. In luciferase reporter studies, mutation of RUNX1 sites in the PLDN promoter reduced activity. RUNX1 overexpression enhanced and RUNX1 downregulation decreased PLDN1 promoter activity and protein expression. RUNX1 downregulation resulted in impaired handling of mepacrine and mislocalization of the DG marker CD63 in HEL cells, indicating impaired DG formation, recapitulating findings on PLDN downregulation. Conclusions These studies provide the first evidence that PLDN is a direct target of RUNX1 and that its dysregulation is a mechanism for platelet DG deficiency associated with RUNX1 haplodeficiency.

Early growth response transcription factor EGR-1 regulates Galphaq gene in megakaryocytic cells.

BACKGROUND: Galphaq (Gene GNAQ) plays a major role in platelet signal transduction but little is known regarding its transcriptional regulation. OBJECTIVES: We studied Galphaq promoter activity using luciferase reporter gene assays in human erythroleukemia (HEL) cells treated with phorbol 12-myristate 13-acetate (PMA) for 24 h to induce megakaryocytic transformation. METHODS AND RESULTS: PMA-treated HEL cells showed enhanced Galphaq expression. Reporter (luciferase) gene studies on 5' upstream construct (up to -116 bp from ATG) revealed a negative regulatory site at -238/-202 and two positive sites at -203/-138 and -1116/-731. The positive regulatory region -203/-138 contained overlapping Sp1/AP-2/EGR-1 consensus sites. Gel shift studies on Galphaq oligonucleotides 1 (-203/-175) and 2 (-174/-152) using HEL cell extracts demonstrated protein binding that was due to early growth response factor EGR-1 at two sites. Mutations in either EGR-1 site markedly decreased the gene activity, indicating functional relevance. Mutation of consensus E-Box motif (-185/-180) had no effect. Reduction in the expression of endogenous EGR-1 with antisense oligonucleotide to EGR-1 inhibited PMA-induced Galphaq transcription. Correspondingly, Egr-1 deficient mouse platelets also showed approximately 50% reduction in the Galphaq expression relative to wild-type platelets. CONCLUSIONS: These studies suggest that Galphaq gene is regulated during PMA-induced megakaryocytic differentiation by EGR-1, an early growth response transcription factor that regulates a wide array of genes and plays a major role in diverse activities, including cell proliferation, differentiation and apoptosis, and in vascular response to injury and atherosclerosis.

Platelet function analyzer (PFA)-100 closure time in the evaluation of platelet disorders and platelet function.

BACKGROUND: Closure time (CT), measured by platelet function analyzer (PFA-100) device, is now available to the clinical laboratory as a possible alternative or supplement to the bleeding time test. AIM: On behalf of the Platelet Physiology Subcommittee of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis (ISTH-SSC), a working Group was formed to review and make recommendations on the use of the PFA-100 CT in the evaluation of platelet function within the clinical laboratory. METHODS: The Medline database was searched to review the published information on the PFA-100 CT in the evaluation of platelet disorders and platelet function. This information, and expert opinion, was used to prepare a report and generate consensus recommendations. RESULTS: Although the PFA-100 CT is abnormal in some forms of platelet disorders, the test does not have sufficient sensitivity or specificity to be used as a screening tool for platelet disorders. A role of the PFA-100 CT in therapeutic monitoring of platelet function remains to be established. CONCLUSIONS: The PFA-100 closure time should be considered optional in the evaluation of platelet disorders and function, and its use in therapeutic monitoring of platelet function is currently best restricted to research studies and prospective clinical trials.

Activation of the tissue factor pathway of blood coagulation during prolonged hyperglycemia in young healthy men.

Patients with diabetes have an increased prevalence of premature atherosclerotic vascular disease, and alterations in plasma coagulation proteins have been incriminated as a possible cause. The roles of hyperglycemia and hyperinsulinemia in the pathogenesis of these changes are unknown. To examine the effects of prolonged hyperglycemia and of selective hyperinsulinemia on the tissue factor pathway of blood coagulation, nine healthy young men were infused with glucose to maintain levels at 11.1 mmol/l (approximately 200 mg/dl) for 18-72 h (hyperglycemia-hyperinsulinemia group). Five normal men were infused with regular insulin to maintain levels comparable to that in the previous group (900 pmol/l, approximately 150 microU/ml) and with glucose to maintain levels at 5.6 mmol/l (approximately 100 mg/dl) (euglycemia-hyperinsulinemia group). Measured were plasma activated factor VII activity (FVIIa), FVII coagulant (FVIIC) activity, FVIII coagulant (FVIIIC) activity, tissue factor pathway inhibitor (TFPI) antigen, and thrombin markers; and serum glucose, insulin, and electrolytes. Plasma FVIIa, FVIIC, FVIIIC, and TFPI rose during hyperglycemic-hyperinsulinemia but not during euglycemic-hyperinsulinemia. Markers of thrombin generation rose transiently and inconsistently during hyperglycemia-hyperinsulinemia. We concluded that in normal subjects, hyperglycemia-hyperinsulinemia induced activation of the tissue factor pathway, reflected by increases in plasma FVIIa, FVIIC, and TFPI. This activation was independent of hyperinsulinemia, hypertriglyceridemia, and hyperosmolality. The elevations in plasma coagulation factors during hyperglycemia-hyperinsulinemia, characteristic of type 2 diabetes, may constitute a potential for enhanced thrombin generation and thrombosis when triggered by exposure of tissue factor, such as during arterial plaque rupture.

Thrombolysis in myocardial infarction (TIMI): comparative studies of coronary reperfusion and systemic fibrinogenolysis with two forms of recombinant tissue-type plasminogen activator.

Coronary recanalization rates and changes in plasma proteins of the fibrinolytic system were evaluated with two preparations of recombinant tissue-type plasminogen activator (rt-PA): the early formulation in liquid excipient ("old" rt-PA) and the later lyophilized form ("new" rt-PA). The dose dependency of coronary recanalization and of effects on plasma proteins was evaluated for the new rt-PA. Four groups of patients were studied: Study 1, 80 mg old rt-PA infused intravenously over 3 hours (n = 113); Study A, 80 mg new rt-PA over 3 hours (n = 47); Study B, 100 mg new rt-PA over 3 hours (n = 83); and Study C, 150 mg new rt-PA over 6 hours (n = 62). With equal doses of 80 mg, coronary recanalization rates at 90 minutes of infusion, determined angiographically, averaged 62% (Study 1) and 45% (Study A) with no overlap of 95% confidence limits. Increasing the dose of the new rt-PA to 100 mg, recanalization rates at 90 minutes averaged 71% (Study B), similar to those observed in Study 1. An increase to 150 mg resulted in higher recanalization rates at 30 minutes of infusion, 42% compared with 24% in Study 1 with no overlap of 95% confidence limits, and comparable rates at 90 minutes, 76 versus 62%. A linear trend test indicated a significant relation (p less than 0.01) between the dose of the new rt-PA and the rate of coronary recanalization at 30, 60 and 90 minutes of infusion. The new rt-PA affected plasma proteins of the fibrinolytic system less than the old form. There was a dose-dependent relation (p less than 0.001) in the effect of the new rt-PA on the plasma proteins. The frequency of bleeding complications was similar in the four study groups. These results indicate that the new rt-PA is less potent than the old rt-PA, in relation to both coronary reperfusion and systemic fibrinogenolysis. A higher and longer dosage regimen caused more rapid recanalization with similar effects on fibrinogenolysis.

Thrombolysis in Myocardial Infarction (TIMI) Trial--phase I: hemorrhagic manifestations and changes in plasma fibrinogen and the fibrinolytic system in patients treated with recombinant tissue plasminogen activator and streptokinase.

Two hundred ninety patients with acute myocardial infarction were treated according to random assignment with an intravenous infusion of either 80 mg of recombinant tissue plasminogen activator (rt-PA) over 3 h or 1.5 million units of streptokinase over 1 h. Patients received an intravenous bolus of heparin (5,000 U [USP]) before pretreatment coronary angiography and a continuous infusion (1,000 U/h) starting 3 h later. The frequency of major and minor hemorrhagic events (33% rt-PA, 31% streptokinase) and associated transfusions (22% rt-PA, 20% streptokinase) were comparable in both groups. More than 70% of bleeding episodes in each group occurred at catheterization or vascular puncture sites. Precipitable fibrinogen levels, measured in plasma samples collected in the presence of a protease inhibitor (aprotinin), declined in rt-PA and streptokinase groups by averages of 26 and 57% at 3 h and by 33 and 58% at 5 h, respectively (rt-PA versus streptokinase, p less than 0.001). At 5 h the plasma plasminogen declined by 57% (rt-PA) and 82% (streptokinase) (p less than 0.001); plasma fibrin(ogen) degradation products were higher in streptokinase-treated patients (244 +/- 12 micrograms/ml, mean +/- SE) than in rt-PA-treated patients (97 +/- 9 micrograms/ml, p less than 0.001). At 27 h, plasma fibrinogen and plasminogen levels were lower and fibrin(ogen) degradation products higher than pretreatment levels in both groups. The frequency of hemorrhagic events was higher in patients with greater changes in plasma factors at 5 h; within treatment groups the levels of fibrin(ogen) degradation products correlated with bleeding complications (p less than 0.005). Thus, in the doses administered, rt-PA induces systemic fibrinogenolysis that is substantially less intense than that induced by streptokinase. The high frequency of bleeding encountered is related to the protocol used, including vigorous anticoagulation, arterial punctures and thrombolytic therapy. These findings emphasize the need for avoidance of invasive procedures and for meticulous care in the selection and management of patients subjected to thrombolytic therapy.

Mapping the platelet proteome: a report of the ISTH Platelet Physiology Subcommittee.

Proteomic technology has the potential to transform the way we analyze platelet biology, through the determination of platelet protein composition and its modification upon stimulation and with disease. We are a considerable way from achieving these goals, however, because of significant limitations in current methodology. It is therefore important to consider the extent to which these aims can be met and the way that proteomic data should be presented and used. These issues are discussed in the present paper by the Platelet Physiology Subcommittee of the ISTH Scientific Standardisation Committee (SSC). It is recommended that proteomic information be combined with data from other experimental approaches to establish a database on protein expression and function in platelets.

Angiographic contrast agent-induced acute hemolysis in a patient with hemoglobin SC disease.

Radiographic contrast media used for angiographic procedures are hyperosmolar and induce sickling in vitro of erythrocytes from patients with sickle cell disorders. We treated a 51-year-old black woman with hemoglobin SC disease, but without a history of painful crises, who developed severe intravascular hemolysis and pulmonary infiltrates following administration of a contrast agent for coronary angiography and ventriculography. This case emphasizes the potential for severe complications following administration of the currently available contrast agents to patients with sickle cell disease. We suggest that newer contrast agents with lower osmolality than the commonly used ones need to be carefully evaluated for radiologic studies in patients with sickle cell disease.

Low incidence of thrombocytopenia with porcine mucosal heparin. A prospective multicenter study.

We treated 193 patients either intravenously (94) or subcutaneously (99) for at least 5 days with porcine intestinal mucosal heparin and followed them up prospectively with frequent platelet counts to determine the incidence of heparin-related thrombocytopenia and arterial thrombosis. None of the patients in the study developed severe thrombocytopenia (platelet count, less than 100 x 10(9)/L) or arterial thrombosis. Eight patients had a platelet count of 100 to 140 X 10(9)/L on one occasion, with a count of greater than 140 x 10(9)/L on the subsequent measurement. The mean (+/- SD) values of the initial and lowest platelet counts during therapy in all patients were 288 +/- 100 x 10(9)/L and 253 +/- 88 x 10(9)/L, respectively, with the lowest counts occurring on day 4.1 +/- 4.2. A least-squares line was computed for each patient to fit the day and counts; the slopes were significantly different from zero and negative in 7.8% of patients and positive in 14.5%. This multicenter study confirms the reports that the incidence of heparin-related severe thrombocytopenia and arterial thrombosis is distinctly low in patients treated with porcine-mucosal heparin.

Secretion defect in platelets stored at 4 degrees C.

To understand the functional changes induced by storage, we have examined the adenine nucleotides of platelets stored for 72 hr at 22 degrees C and 4 degrees C. Ten platelet concentrates (PC) were stored at each temperature with five in each group having a final volume of 50 ml and 30 ml. The total ATP and ADP content of platelets decreased following storage in all 4 groups of PC, with the decrease being greater in the PC stored at 22 degrees C than those at 4 degrees C. The mean thrombin secretable ATP + ADP content of platelets from PC stored at 22 degrees C and 4 degrees C were 29.7% and 19.7% of the total content, respectively (p less than 0.001). Thus, cold stored platelets have a higher total content of ATP + ADP but secrete distinctly lesser amounts than 22 degrees C stored platelets. Labeling of the metabolic pool adenylates with 14C-adenine revealed a greater decrease in the adenylate energy charge of the platelets stored at 4 degrees C. The secretion defect demonstrated in cold stored platelets may be related to the inability of these platelets to maintain ATP homeostasis.