Quality of plasma for fractionation--does it matter?

Many plasmapheresis techniques cause greater activation of platelets, complement and coagulation than does simple whole blood collection. Activation of the coagulation cascade has been particularly evident in tests for potential thrombogenicity in prothrombin complex concentrates made from apheresed plasma. Attempts to improve the factor VIII content and fractionation yield of source plasma have centred on rapid freezing, increased concentration of anticoagulants and the exploitation of anticoagulants optimal for the preservation of coagulant, rather than cellular, activities. The cumulative advantage is of the order of 10% over recovered plasma. There are potential pitfalls in applying low-citrate anticoagulation strategies to plasmapheresis. Recalcification of citrated plasma, under cover of an optimal concentration of heparin, might be explored more vigorously.

Multiple Beau's lines in a patient with fever of unknown origin

We describe a case of fever of unknown origin (FUO) of 9 months' duration in which the finding of regularly spaced multiple Beau's lines (the "ladder nail" sign) pointed to the possibility of a relapsing fever of the Pel-Ebstein variety and an underlying lymphoma. Subsequent investigation confirmed the association of the Beau's lines and fever, as well as the diagnosis of Hodgkin's disease as the cause of the FUO. In this setting, Beau's lines may provide an important diagnostic clue and should be carefully looked for on physical examination.

Mediastinal mass with right pleural effusion

We have described the case of a 65-year-old man who had a right hemothorax from rupture of an aneurysm of the ascending thoracic aorta and survived. This type of subacute presentation with survival of the patient has not been documented previously in contemporary medical literature.

Verapamil intoxication: a literature review of overdoses and discussion of therapeutic options

Calcium channel antagonists can be quite toxic. In the management of poisoning, early recognition is critical. Calcium channel antagonists are frequently prescribed, and the potential for serious morbidity and mortality with overdosage is significant. Ingestion of these agents should be suspected in any patient who presents in an overdose situation with unexplained hypotension and conduction abnormalities. The potential for toxicity should be noted in patients with underlying hepatic or renal dysfunction who are receiving therapeutic doses. Because there is no specific antidote, decontamination of the gastrointestinal tract is crucial. Intravenous calcium should be administered to symptomatic patients because it is relatively innocuous and may be beneficial. Volume expansion should be the initial approach to hypotension unrelated to bradycardia. Patients who have had a verapamil overdose should be observed in intensive care units where Swan-Ganz catheterization and ventricular pacing are routinely available. The choice of sympathomimetic agents for treatment remains controversial. According to the published literature, isoproterenol, epinephrine, and norepinephrine may be more effective in improving bradycardia and the resultant hypotension than dopamine. However, none of these agents is universally effective. A more logical approach may be to improve cardiac output with agents like amrinone. Bay K 8644 and 4-aminopyridine show promise as potential antidotes but at present are still experimental.

Regulation of tobacco acetolactate synthase gene expression

Acetolactate synthase (ALS) catalyzes the first common step in the biosynthesis of isoleucine, leucine, and valine. The previous cloning of two tobacco (Nicotiana tabacum) ALS genes (SurA and SurB) has allowed transcript accumulation from these genes to be monitored. mRNA blot analysis of ALS transcripts showed a message size of 2.2 kb. Quantitation of the levels of ALS messages in tobacco organs indicated that there was 3- to 4-fold variation in the levels of expression of the ALS genes in different organs. This variability correlated with the developmental stage of the samples, with the highest levels of expression found in developing organs. In situ hybridizations of anti-mRNA probes to plant sections established that ALS messages are most prevalent in metabolically active and dividing cells of roots, stems, and floral tissue. Using RNase protection assays, the transcriptional start sites of the ALS genes were determined, and the expression levels of the two tobacco ALS genes were then followed separately. Both tobacco ALS genes are expressed in a coordinated manner in all tobacco organs examined, with the SurB gene being consistently expressed at higher levels than the SurA gene.

Sonography of the scrotum after orchiectomy: normal and abnormal findings

Sonography is the primary imaging technique for evaluating the scrotal contents. In this pictorial essay, we illustrate a range of normal and abnormal sonographic findings in patients after orchiectomy, including the appearances of the normal postorchiectomy space, acute and subacute hematomas, recurrent neoplasm, second primary tumor in the remaining testis, and testicular prostheses.

Telomere reduction in endometrial adenocarcinoma

OBJECTIVE

Some of the genomic instability that is observed in solid tumors may be due to the loss of telomeric sequences. These experiments were designed to compare the number of telomeric repeat sequences in endometrial adenocarcinoma with that found in adjacent normal tissue.

STUDY DESIGN

Deoxyribonucleic acid was extracted from normal and malignant uterine tissue of 11 patients undergoing hysterectomy for treatment of endometrial adenocarcinoma and also from five endometrial carcinoma cell lines. The relative number of telomeric repeat sequences in each sample was measured by hybridization of these deoxyribonucleic acids to a probe specific for the human telomeric repeat. Hybridization signals were quantified by autoradiography and a beta-particle detection system.

RESULTS

A reduction of telomeric repeat sequences in tumor versus normal tissue was found in 10 of 11 cases. Telomere reduction was also seen in endometrial carcinoma cell lines.

CONCLUSIONS

Telomere reduction is a genetic characteristic of many endometrial tumors. Telomere reduction may contribute to the genesis and progression of endometrial carcinoma, or it may be a secondary effect of the tumorigenesis process.

Production and therapeutic use of a factor XI concentrate from plasma

Factor XI deficiency is an uncommon bleeding disorder usually manifested by excessive bleeding after surgery or trauma. Until recently the only effective therapy has been fresh-frozen plasma (FFP) infusion. We describe the efficacy and safety of a new factor XI concentrate produced from human donor plasma by a modification of the method used for antithrombin III concentrate. The mean recovery of factor XI in the circulation measured on 62 occasions was approximately 91% of the injected dose, and the mean half-disappearance-time was 52 h. The concentrate was used for 31 invasive procedures in 30 patients, including 16 patients who had a definite bleeding tendency on previous occasions, with normal haemostasis being achieved in all but 1. Only 1 patient (previously experiencing allergy to FFP) experienced adverse effects during infusion. Monitoring of liver function tests and viral antibody status in suitable patients has shown no evidence of transmission of hepatitis viruses, HIV-1 or parvovirus B19. We conclude that this concentrate provides effective treatment for patients with factor XI deficiency. Preliminary results suggest safety from virus transmission, but this needs to be established in further studies of previously untreated patients.

Obstructive sleep apnea syndrome

Over the past 2 decades, we have gained great insight into the sleep apnea syndromes. Though progress in this field continues, many problems, including an incomplete understanding of the disease and its natural history, remain. Future work should clarify these areas as well as provide a better understanding of our available therapeutic options.

Intracerebral haemorrhage due to acquired factor XIII inhibitor--successful response to factor XIII concentrate

A 63-year-old woman presented with extensive bruising. An inhibitor to factor XIII was detected. Subsequent subcutaneous bruising and soft tissue haemorrhage into the left foot were treated with infusions of pasteurized factor XIII concentrate with good effect. Immunosuppression with cyclophosphamide was attempted but in spite of this she suffered a right cerebral haemorrhage necessitating further intensive therapy with factor XIII concentrate. This overcame the inhibitor, adequate post-infusion factor XIII levels were achieved and she made an excellent recovery. Factor XIII concentrate was well tolerated with no evidence of transmission of hepatitis or HIV infection. The inhibitor appeared to interfere with haemostasis by hindering the fibrin binding site of factor XIII, resulting in interference in clot-solubility tests. Subsequently the inhibitor resolved.

A pilot study of antithrombin replacement in intensive care management: the effects on mortality, coagulation and renal function

A prospective, randomized, controlled trial to examine the effects of antithrombin supplementation on mortality, coagulation and renal function has been carried out on 132 intensive care patients. Antithrombin activity was measured in all patients on admission to the intensive care unit (ICU). Patients with an antithrombin activity of less than 70% were randomized to either receive antithrombin replacement or to act as controls. Antithrombin activity was maintained above 70% in the treated patients throughout their stay on ICU. Ninety-three patients had an antithrombin activity of less than 70% and 35 received replacement therapy. Patients with antithrombin activity below 70% remained on the ICU significantly longer and had a significantly higher mortality rate than patients with antithrombin activity above 70%. Antithrombin supplementation neither reduced mortality nor shortened the intensive care stay. Fifty patients with reduced antithrombin activity remained on the ICU for at least 4 days, 25 received antithrombin and 25 acted as controls; coagulation parameters and renal function have been monitored in these patients. Fibrinogen concentration and platelet count were unaffected by antithrombin replacement. Antithrombin supplementation did not appear to reduce the incidence of impaired renal function in sepsis, trauma and postoperative patients. The creatinine clearance fell below 20 ml/min in eight patients in the no-treatment arm while by comparison only three patients in the treatment arm developed impaired renal function. Our study does not demonstrate a clear role for the use of antithrombin supplementation in intensive care, however the finding that antithrombin reduced renal impairment is encouraging and a larger study to confirm this finding is at present underway.

Activated neutrophils increase microvascular permeability in skeletal muscle: role of xanthine oxidase

To determine the role of xanthine oxidase in the microvascular dysfunction produced by activated granulocytes, we examined the effect of xanthine oxidase depletion or inhibition on the increase in microvascular permeability produced by infusion of the neutrophil activator phorbol myristate acetate (PMA). Changes in vascular permeability were assessed by measurement of the solvent drag reflection coefficient for total plasma proteins (sigma) in rat hindquarters subjected to PMA infusion in xanthine oxidase-replete and -depleted animals, in animals pretreated with the xanthine oxidase inhibitor oxypurinol, and in animals depleted of circulating neutrophils by pretreatment with antineutrophil serum (ANS). Xanthine oxidase depletion was accomplished by administration of a tungsten-supplemented (0.7 g/kg diet) molybdenum-deficient diet. In animals fed the tungsten diet, muscle total xanthine dehydrogenase plus xanthine oxidase activity was decreased to less than 10% of control values. Estimates of sigma averaged 0.84 +/- 0.04 in control hindquarters, whereas PMA infusion was associated with a marked increase in microvascular permeability (decrease in sigma to 0.68 +/- 0.03). PMA infusion also caused an increase in the amount of the radical-producing oxidase form of xanthine oxidase (from 3.9 +/- 0.05 to 5.6 +/- 0.4 mU/g wet wt). ANS pretreatment attenuated this permeability increase (sigma = 0.77 +/- 0.04) and diminished the rise in xanthine oxidase activity (4.9 +/- 0.5 mU/g wet wt). Xanthine oxidase depletion with the tungsten diet or pretreatment with oxypurinol had no effect on this neutrophil-mediated microvascular injury (sigma = 0.69 +/- 0.06 and 0.67 +/- 0.03, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Oxidant-mediated, CD18-dependent microvascular dysfunction induced by complement-activated granulocytes

To determine the mechanisms whereby complement-activated granulocytes induce microvascular dysfunction in skeletal muscle, we examined the effect of antineutrophil serum (ANS), IB4 (a monoclonal antibody that inhibits CD18-dependent neutrophil adherence), xanthine oxidase inhibition or inactivation, deferoxamine, and catalase on the increase in canine gracilis muscle microvascular permeability induced by intravascular administration of zymosan-activated plasma (ZAP). Changes in vascular permeability were assessed by measurement of the solvent drag reflection coefficient (sigma) for total plasma proteins, and the extent of neutrophil infiltration was estimated by assessing muscle myeloperoxidase activity. ZAP infusion was associated with a marked increase in vascular permeability compared with control muscles that received no treatment or to muscles treated with zymosan heat-inactivated plasma (ZIP) (sigma = 0.51 +/- 0.04, 0.89 +/- 0.02, and 0.90 +/- 0.01, respectively). Estimates of sigma in animals rendered neutropenic with ANS, or treated with IB4, deferoxamine, or catalase before ZAP infusion were not significantly different from values obtained in control or ZIP-treated muscles (sigma = 0.96 +/- 0.02, 0.88 +/- 0.03, 0.85 +/- 0.02, and 0.79 +/- 0.01, respectively). However, xanthine oxidase inactivation or inhibition provided no protection from this ZAP-induced microvascular dysfunction (sigma = 0.58 +/- 0.02 and 0.58 +/- 0.01, respectively). In addition, neutropenia and inhibition of neutrophil adherence also prevented ZAP-induced increases in vascular resistance and tissue neutrophil infiltration.(ABSTRACT TRUNCATED AT 250 WORDS)

Transparent polyurethane (Omiderm) dressing for free flaps

A transparent polyurethane dressing (Omiderm) for free flaps is presented. Considering the importance of reliable flap monitoring postoperatively, this synthetic membrane allows for constant ability to observe the flap, assess the capillary filling, and detect the blood flow with an ultrasound Doppler device.

Effect of exercise on complement activity

Complement measurements of C1, C1q, C2, C3, C4, C5; the anaphylatoxins, C3a, C4a, and C5a; and total hemolytic activity of the classical and alternative pathways were made in 26 experienced adult runners before and after shortterm aerobic exercise. The baseline results were compared with those of nonexercising age-matched controls. In most subjects tested, running resulted in nanogram increases in C3a and C4a with corresponding decreases in the hemolytic activity of C4 (C4H). Baseline values of C3 and C4H were decreased significantly in runners when compared with nonexercising controls. Preliminary studies measuring the effect of exercise on C3a levels were also done in three asthmatic runners. Mean resting and postexercise levels, and exercise-induced increases in C3a anaphylatoxin in the asthmatic subjects were significantly higher than in the nonasthmatic subjects. The findings indicate that short-term exercise results in the activation of C3 and C4 and subsequent generation of C3a and C4a anaphylatoxins, and suggest that both activation of the classical pathway of complement and a selective downregulation of C3 production may occur in persons regularly engaged in aerobic exercise. The exaggerated generation of C3a by asthmatic subjects during exercise raises the possibility that anaphylatoxins play an etiologic role in exercise-induced asthma.

Skeletal muscle oxidative capacity, antioxidant enzymes, and exercise training

The purposes of this study were to determine whether exercise training induces increases in skeletal muscle antioxidant enzymes and to further characterize the relationship between oxidative capacity and antioxidant enzyme levels in skeletal muscle. Male Sprague-Dawley rats were exercise trained (ET) on a treadmill 2 h/day at 32 m/min (8% incline) 5 days/wk or were cage confined (sedentary control, S) for 12 wk. In both S and ET rats, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) activities were directly correlated with the percentages of oxidative fibers in the six skeletal muscle samples studied. Muscles of ET rats had increased oxidative capacity and increased GPX activity compared with the same muscles of S rats. However, SOD activities were not different between ET and S rats, but CAT activities were lower in skeletal muscles of ET rats than in S rats. Exposure to 60 min of ischemia and 60 min of reperfusion (I/R) resulted in decreased GPX and increased CAT activities but had little or no effect on SOD activities in muscles from both S and ET rats. The I/R-induced increase in CAT activity was greater in muscles of ET than in muscles of S rats. Xanthine oxidase (XO), xanthine dehydrogenase (XD), and XO + XD activities after I/R were not related to muscle oxidative capacity and were similar in muscles of ET and S rats. It is concluded that although antioxidant enzyme activities are related to skeletal muscle oxidative capacity, the effects of exercise training on antioxidant enzymes in skeletal muscle cannot be predicted by measured changes in oxidative capacity.

Neutrophil-mediated microvascular dysfunction in postischemic canine skeletal muscle. Role of granulocyte adherence

Recent studies implicate a role for granulocytes in the genesis of the microvascular and parenchymal cell dysfunction, which occurs upon reperfusion of ischemic tissues. Although the molecular mechanisms underlying this neutrophil-mediated injury are not completely understood, it is clear that an essential first step in granulocyte migration from the vascular lumen to the interstitial space is adherence to vascular endothelium. The purpose of this study was to determine whether prevention of neutrophil adherence with monoclonal antibody IB4 directed against the neutrophil CD11/CD18 glycoprotein adherence complex or neutrophil depletion with a specific polyclonal antineutrophil serum would attenuate the microvascular dysfunction seen in postischemic skeletal muscle. Changes in vascular permeability were assessed by measurement of the solvent drag reflection coefficient for total plasma proteins (sigma) in isolated canine gracilis muscle subjected to ischemia/reperfusion, ischemia/reperfusion plus antineutrophil serum, or ischemia/reperfusion plus IB4. Estimates of sigma averaged 0.83 +/- 0.04 in nonischemic, control gracilis muscles, while ischemia/reperfusion was associated with a marked increase in vascular permeability (decrease in sigma to 0.54 +/- 0.04) and vascular resistance (increased by 135 +/- 41% over the control value). Prevention of neutrophil adherence or neutrophil depletion prevented this increase in vascular permeability (sigma = 0.80 +/- 0.03 and 1.01 +/- 0.06, respectively) and resistance (decrease of 16.51 +/- 8.0% and increase of 2.4 +/- 4.6% over control values, respectively). The results of this study suggest that neutrophils play a critical role in the genesis of microvascular dysfunction in postischemic skeletal muscle. Furthermore, neutrophil adherence to vascular endothelium appears to be a prerequisite for the production of this injury.

GABAergic responses in ventrolateral medulla in spontaneously hypertensive rats

Gamma-Aminobutyric acid (GABA) and the GABA antagonist bicuculline methiodide were used to investigate the role of GABAergic transmission in the rostral and caudal ventrolateral medulla in 12- to 13-wk-old spontaneously hypertensive (SH) (n = 7) and normotensive, control Wistar-Kyoto (WKY) (n = 7) rats. Animals were anesthetized with urethan (1.25 g/kg sc), paralyzed with gallamine triethiodide (10 mg/kg iv), and artificially ventilated. Femoral arterial and venous catheters were inserted for the measurement of mean arterial pressure (MAP) and heart rate responses and for intravenous infusions. The ventral surface of the brain stem then was exposed. The responsiveness of the rostral ventrolateral medulla to GABA was compared in SH and WKY rats using unilateral microinjections (30 nl) of GABA at 1, 10, and 100 mM concentrations, which produced significantly (P less than 0.05) larger decreases of MAP in SH rats compared with WKY at the 10 and 100 mM concentrations (-37.3 +/- 2.8 mmHg for SH vs. -27.3 +/- 2.7 mmHg for WKY at 100 mM). Tonic GABAergic inhibition was gauged using bilateral microinjections (30 nl) of bicuculline (2 and 4 mM) into the rostral ventrolateral medulla, which caused significantly larger increases in MAP in the WKY group (+84.8 +/- 8.5 mmHg at 4 mM) compared with the SH group (+14.9 +/- 5.8 mmHg at 4 mM). In contrast, the ability to drive sympathetic outflow by microinjection of L-glutamate in the rostral ventrolateral medulla was not significantly different between WKY and SH rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular effects of L-glutamate and tetrodotoxin microinjected into the rostral and caudal ventrolateral medulla in normotensive and spontaneously hypertensive rats

The purpose of this study was to compare the responsiveness of the rostral and caudal ventrolateral medulla in spontaneously hypertensive (SH) and normotensive Wistar-Kyoto (WKY) rats to microinjection of L-glutamate, and to estimate tonic output of these areas by microinjecting the neurotoxin tetrodotoxin. Rats were anesthetized with 1.25 g/kg urethane s.c., implanted with arterial (femoral) and venous (femoral) catheters, artificially ventilated and paralyzed with gallamine triethiodide (10 mg/kg). Using a ventral approach to the brainstem, the mean arterial pressure and heart rate responses to microinjection (30 nl) of L-glutamate (1, 10 and 100 mM) and tetrodotoxin (10 microM) into the rostral and caudal ventrolateral medulla were compared in SH (n = 7) and WKY (n = 7) groups. Microinjection of L-glutamate into the rostral ventrolateral medulla produced equivalent increases in mean arterial pressure (maximum +33 +/- 3 and +36 +/- 6 mm Hg, SH and WKY groups respectively) and minimal changes in heart rate. Similar administration of L-glutamate into the caudal ventrolateral medulla caused decreases in mean arterial pressure and heart rate; changes in mean arterial pressure were significantly greater in the SH group than in the WKY group (-52.3 +/- 2.9 mm Hg for SH, -22.6 +/- 2.6 mm Hg for WKY). Bilateral microinjection of tetrodotoxin into the caudal ventrolateral medulla produced significantly larger increases of mean arterial pressure in WKY rats (+8 +/- 4 vs +46 +/- 8 mm Hg for SH vs WKY). These data indicate that SH rats may have a lower tonic activity of neurons in the caudal ventrolateral medulla, resulting in a lower restraining influence on sympathetic outflow in the SH rat.

The rostral and caudal ventrolateral medulla in young spontaneously hypertensive rats

This study was designed to compare the cardiovascular influences of the rostral ventrolateral medulla (RVLM) and the caudal ventrolateral medulla (CVLM) in young (5-6 weeks) spontaneously hypertensive (SH) and normotensive Wistar-Kyoto (WKY) rats. SH and WKY groups had similar pressor and depressor responses to microinjection of L-glutamate into the RVLM and the CVLM, respectively. In addition the results of this study indicate a reduced tonic sympathoinhibitory function of the CVLM in young SH rats, which may contribute to the development of hypertension in the spontaneously hypertensive rat.

Posterior hypothalamic influences on cardiovascular effects of aortic nerve stimulation

The purpose of this study was to examine the influence of stimulation of the posterior hypothalamus on the baroreflex responses produced by stimulation of the aortic depressor nerve. Animals were initially anesthetized and implanted with a bipolar electrode in the posterior hypothalamus. Three to 5 days later, animals were anesthetized with urethan, and the left aortic depressor nerve was dissected and placed on a bipolar platinum-iridium electrode. The effects of electrical stimulation of the posterior hypothalamus (0, 160, and 280 microA) were examined in baroreflex-intact and acutely sinoaortic baroreceptor-denervated animals, and the responses to aortic nerve stimulation (2, 8, 16, and 32 Hz) were examined during each level of hypothalamic stimulation. The first set of experiments was performed in baroreceptor-intact animals; e.g., in animals with arterial baroreceptor inputs intact from both carotid sinus regions in addition to intact right aortic baroreceptor afferent pathways. In that group, stimulation of the posterior hypothalamus attenuated the bradycardia and depressor effects of aortic nerve stimulation. When influences from other baroreceptor inputs were removed with acute sinoaortic baroreceptor denervation, posterior hypothalamic stimulation interrupted the reflex bradycardia due to aortic nerve stimulation; however, the depressor response to aortic nerve stimulation was not attenuated. Similar to the arterial pressure response, hypothalamic stimulation did not attenuate the decreases in mesenteric and iliac vascular resistance produced by aortic nerve stimulation in the baroreflex-denervated group. We conclude that posterior hypothalamic stimulation attenuates baroreflex-mediated bradycardia but does not alter baroreflex control of arterial pressure and peripheral vascular resistance.

Role of xanthine oxidase in postischemic microvascular injury in skeletal muscle

Previous reports indicate that allopurinol, a xanthine oxidase inhibitor, attenuates the microvascular injury produced by reperfusion of ischemic skeletal muscle. To further assess the role of xanthine oxidase in ischemia/reperfusion (I/R) injury, we examined the effect of xanthine oxidase depletion or inhibition on the increase in microvascular permeability produced by I/R. Changes in vascular permeability were assessed by measurement of the solvent drag reflection coefficient for total plasma proteins (sigma) in rat hindquarters subjected to 2 h of ischemia and 30 min of reperfusion in xanthine oxidase-replete and -depleted animals and in animals pretreated with the xanthine oxidase inhibitor oxypurinol. Xanthine oxidase depletion was accomplished by administration of a tungsten-supplemented (0.7 g/kg diet), molybdenum-deficient diet. In animals fed the tungsten diet, muscle total xanthine dehydrogenase plus xanthine oxidase activity was decreased to less than 10% of control values. Estimates of sigma averaged 0.85 +/- 0.04 in nonischemic (continuous perfusion for 2.5 h) hindquarters, whereas muscle xanthine oxidase activity averaged 3.3 +/- 0.4 mU/g wet wt. I/R was associated with a marked decrease in sigma (0.54 +/- 0.02), whereas xanthine oxidase activity was increased to 5.8 +/- 0.5 mU/g wet wt. These results indicate that I/R produced a dramatic increase in vascular permeability coincident with an increase in muscle xanthine oxidase activity. Xanthine oxidase depletion with the tungsten diet or pretreatment with oxypurinol attenuated this permeability increase (sigma = 0.72 +/- 0.03 and 0.77 +/- 0.7, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Severely heated therapeutic factor VIII concentrate of high specific activity

A new method for the manufacture of a heated factor VIII concentrate of high specific activity (2-6 IU factor VIII:C/mg protein) has been developed. Addition of heparin to cryoprecipitate extract at acid pH precipitated fibrinogen and fibronectin. Factor VIII was then recovered from the supernatant by precipitation with glycine and sodium chloride. After re-solution and desalting on Sephadex G-25, the concentrate was sterile-filtered and lyophilised. The dried product was stable to heating in the final container at 80 degrees C for 72 h. Data from 25 consecutive batches of concentrate prepared from 1,200-1,500 kg plasma pools are presented. The mean final yield of heated product was 190 IU factor VIII:C/kg plasma. The concentrate has been found to be safe and effective in clinical use.

Pneumonias

Pneumonia is a common disease seen in Emergency Department patients and is caused by a wide range of pathogens. The clinical and laboratory data that help to provide a specific etiologic diagnosis of the pneumonia are reviewed. In addition, current recommendations for the treatment and hospitalization of patients with pneumonia are detailed.

Role of iron in postischemic microvascular injury

Iron-catalyzed formation of hydroxyl radicals has been postulated to occur during reperfusion of ischemic tissues. To assess the role of iron-catalyzed oxidant production in ischemia/reperfusion (I/R) injury to skeletal muscle, we examined the effects of deferoxamine (an iron chelator) and apotransferrin (an iron-binding protein) on the increased vascular permeability produced by I/R in isolated, pump-perfused rat hindquarters. Solvent drag reflection coefficients (sigma) were measured in hindquarters subjected to 2 h of ischemia and 30 min of reperfusion with either no pretreatment, pretreatment with 50 mg/kg deferoxamine, 200 mg/kg apotransferrin, or iron-loaded deferoxamine (50 mg/kg). I/R alone was associated with an increase in vascular permeability as indicated by the significantly lower estimates of sigma obtained after I/R (0.68 +/- 0.03) compared with those obtained in nonischemic preparations (0.82 +/- 0.02). Pretreatment with deferoxamine or apotransferrin attenuated this permeability increase (sigma = 0.83 +/- 0.03 and 0.86 +/- 0.02, respectively), whereas pretreatment with iron-loaded deferoxamine afforded no protection (sigma = 0.71 +/- 0.02). These findings are consistent with the hypothesis that iron-catalyzed oxidant production is important in the genesis of microvascular injury following I/R. Since the enzyme xanthine oxidase has been implicated as a major source of oxidants generated during reperfusion, we also measured tissue levels of xanthine oxidase and xanthine dehydrogenase in muscle samples obtained from the same hindquarters in which we measured permeability changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Free radical defense mechanisms and neutrophil infiltration in postischemic skeletal muscle

A growing body of experimental data indicates that reactive oxygen metabolites such as superoxide, hydrogen peroxide, and hydroxyl radicals may mediate the microvascular and parenchymal injury produced by reperfusion of ischemic skeletal muscle. One potential source of these reactive oxygen metabolites is the inflammatory neutrophil. To assess neutrophil accumulation in postischemic skeletal muscle, we measured tissue myeloperoxidase (MPO) activity in skeletal muscle biopsies taken during control, after 4 h of ischemia, and after 1 h of reperfusion. Tissue levels of reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) were measured in the same samples to identify alterations in tissue free radical defense mechanisms due to ischemia-reperfusion. Reperfusion of ischemic skeletal muscle was associated with a dramatic increase in tissue neutrophil content (as reflected by a 26-fold increase over control in tissue MPO activity after 1 h of reperfusion) and a concurrent 50% decrease in GSH content. Tissue CAT and SOD activities were unaffected by ischemia-reperfusion. These results suggest a possible relationship between ischemia-reperfusion-induced injury, neutrophil infiltration, and the reduction in tissue GSH.

Hypoxic reperfusion attenuates postischemic microvascular injury

The results of several recent studies have demonstrated that reactive oxygen metabolites are responsible for a major portion of ischemia/reperfusion (I/R) injury in skeletal muscle. Presumably, the cytotoxic oxidants are produced during reperfusion when molecular oxygen (the source of the reactive oxygen metabolites) is reintroduced to the tissues. The purpose of this study was to test the hypothesis that molecular oxygen must be provided at reperfusion to produce I/R injury in skeletal muscle. Isolated, maximally vasodilated (papaverine) canine gracilis muscles were reperfused, after 4 h of inflow occlusion, from reservoirs containing autologous blood equilibrated with either 95% O2-5% CO2 or 95% N2-5% CO2 gas mixtures. Arterial PO2 fell from approximately 120 mmHg to less than 3-5 mmHg, during the use of nitrogen. The solvent drag reflection coefficient for total plasma proteins (sigma f) and total vascular resistance was determined for the following conditions: control (no ischemia), reperfusion with oxygenated blood after 4 h ischemia; and reperfusion (after 4 h ischemia), first with anoxic blood and then oxygenated blood. Reperfusion with oxygenated blood, after 4 h of ischemia, significantly reduced solvent drag reflexion coefficient (sigma f) from 0.93 +/- 0.02 to 0.63 +/- 0.02, indicating a dramatic increase in vascular permeability. Total vascular resistance increased from 6.1 +/- 1.1 mmHg.ml-1.min.100 g during the preischemic period to 12.9 +/- 3.0 mmHg.ml-1.min.100 g during normoxic reperfusion. In muscles reperfused with anoxic blood, sigma f averaged 0.82 +/- 0.06, whereas vascular resistance increased by 56 +/- 13%.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of glucagon in intestinal hyperemia associated with early experimental diabetes mellitus

The role of glucagon as a blood-borne mediator of the intestinal hyperemia associated with experimental diabetes mellitus was assessed in anesthetized fasted (18-24 h) rats 4 wk after the administration of streptozotocin (65 mg/kg body wt) or its vehicle. Selective removal of pancreatic glucagon from the circulation was accomplished by the intravenous administration of a highly specific glucagon antiserum. Blood flow to the gastrointestinal tract and kidneys was measured with radioactive microspheres using the reference sample technique. Blood flows were increased by at least 60% in each segment of the gastrointestinal tract of diabetic animals compared with control rats. Glucagon antiserum had no effect on blood flows in the gastrointestinal tract of control animals. However, the antiserum produced a significant reduction in blood flow to the stomach (26%), duodenum (25%), jejunum (12%), and kidneys (16%) in diabetic rats. There was no change in blood flow to the ileum or colon of diabetic animals with antiserum administration. The results of this study support the hypothesis that glucagon mediates a portion of the hyperemia noted in the stomach, duodenum, and jejunum. However, glucagon does not appear to play a role in the genesis of the hyperemia noted in more distal segments of the gastrointestinal tract (ileum and colon). A possible role for glucagon in the maintenance of renal blood flow in diabetic rats is suggested.

Hyper-IgE and human immunodeficiency virus infection

A 39-year-old black male who is an intravenous drug abuser developed certain clinical manifestations that were consistent with the hyper-IgE syndrome. These included an extremely elevated IgE (greater than 2000 IU/mL), extensive eczematoid dermatitis, and recurrent soft tissue infections. He had no history of atopic disease as a child. Immunophenotypic analysis of peripheral blood mononuclear cells showed a significant decrease in helper (CD 4) cells with a normal concentration of suppressor (CD 8) cells. Human immunodeficiency virus (HIV) antibody was detected in his serum. Previous studies of patients with atopic dermatitis as well as of patients with the hyper-IgE syndrome characteristically show decreases in total suppressor lymphocyte concentrations in peripheral blood. These results led some investigators to postulate that high IgE concentrations in patients with atopic dermatitis result from defective IgE specific suppression. More recent evidence suggests that helper cell function may be the more critical impairment in these disorders. The development of a hyper-IgE syndrome in this setting of T-helper cell viral affliction lends further support to the hypothesis that helper lymphocyte defects may have a key role in the development of atopic dermatitis and the hyper-IgE syndrome.

Susceptibility of dysgonic fermenter 2 to antimicrobial agents in vitro

Dysgonic fermenter 2 (DF-2) is a fastidious, gram-negative organism well recognized as a cause of fulminant septicemia in patients without spleens or patients with alcoholic cirrhosis. In vitro antibiotic susceptibility testing of eight strains with a Schaedler broth dilution technique revealed DF-2 to be susceptible to all of the antibiotics tested except aztreonam. Previous reports that DF-2 is aminoglycoside resistant were based on disk diffusion or agar dilution assays that may be less reliable given the slow growth of the organism and its requirement for CO2 incubation. Penicillin is commonly used as prophylaxis after dog bites and has excellent activity against DF-2.

Nosocomial infections in long-term facilities

We studied the incidence and prevalence of hospital-acquired infections in our intermediate-care units and the Nursing Home Care Unit at the Veterans Administration Medical Center, Johnson City, TN over a 4-year period (1980 through 1983). The global infection rate was 3.86 per 1,000 patient care days. The lower respiratory tract was the most common site of infection, followed by urinary tract infections, skin infections, bacteremia, wound infections, and infections at other sites. The prevalence study conducted by monthly visits over a 1-year period showed similar results. All of our patients were elderly males with multiple underlying diseases and poor performance status. The high incidence of nosocomial infections in chronic-care facilities relates to the poor functional assessment of the patients, which may increase the susceptibility of these patients to develop infections, mainly lower respiratory and cutaneous infections.

Critical role of cellular ras proteins in proliferative signal transduction

In the experiments described above, a neutralizing anti-ras antibody was utilized to study the role of ras protein in normal cell proliferation. Initially, it was demonstrated that the antibody was specific for ras protein, and that ras activity was efficiently inhibited. With the neutralizing antibody, it was first shown that ras activity is required for the proliferation of all normal cell types tested. ras activity was required just prior to initiation of S phase. The transforming activity of several retroviral oncogenes was also blocked following anti-ras injection. This included the tyrosine kinase, plasma-membrane-associated proteins, and an oncogene derived from a growth factor. On the other hand, cytoplasmic oncogenes with serine kinase activity were not dependent on ras activity for expression of the transformed phenotype. These observations form the basis of our model for proliferative signal transduction. We propose that the action of either growth factors, their receptor molecules, or related oncogenes initiate an intracellular signal received by ras proteins and then transferred by ras to cytoplasmic serine kinase oncogenes. This signal transduction system directly regulates cellular proliferation. Although further evidence in support of this model is needed, it appears from our studies that the mechanism of signaling between tyrosine kinases and ras proteins might be at the level of phospholipid metabolism. This observation is based on the fact that the mitogenic lipid molecules tested were remarkably dependent on ras activity, even more so than the growth factors or related oncogenes tested. Finally, our work suggests a fundamental distinction between normal and tumor cells. All the normal cell types tested were efficiently inhibited in proliferation by the injected antibody. Tumor cells, on the other hand, were never completely inhibited by the antibody and often were not inhibited at all. The presence of an activated ras oncogene within the tumor assured at least a partial role for ras activity in the proliferation of the mature tumor line. The significance of the observed distinction between normal and tumor cells is not known. The fact that this distinction involves a protein with an apparently critical role in normal proliferation suggests that the observation might be important.

Isolation and characterization of plant genes coding for acetolactate synthase, the target enzyme for two classes of herbicides

Acetolactate synthase (ALS) is the first common enzyme in the biosynthetic pathways to valine, isoleucine, and leucine. It is the target of two structurally unrelated classes of herbicides, the sulfonylureas and the imidazolinones. Genomic clones encoding ALS have been isolated from the higher plants Arabidopsis thaliana and Nicotiana tabacum, using a yeast ALS gene as a heterologous hybridization probe. Clones were positively identified by the homology of their deduced amino acid sequences with those of yeast and bacterial ALS isozymes. The tobacco and Arabidopsis ALS genes have approximately 70% nucleotide homology, and encode mature proteins which are approximately 85% homologous. Little homology is seen between the amino acid sequences of the presumptive N-terminal chloroplast transit peptides. Both plant genes lack introns. The tobacco ALS gene was isolated from a line of tobacco which is resistant to the sulfonylurea herbicides due to an alteration in ALS. The tobacco gene which was isolated codes for an ALS that is sensitive to the herbicides, as assayed by transformation of the gene into sensitive tobacco cells.

Response of the microcirculation in rat cremaster muscle to peripheral and central sympathetic stimulation

Microvascular diameter and flow responses to peripheral and central sympathetic stimulation were measured in different segments of the arteriolar network in rat cremaster muscle. For peripheral stimulation, a bipolar electrode was placed on the internodal segment of the lumbar sympathetic chain between ganglia L1 and L2. For central stimulation, a bipolar electrode was stereotaxically implanted in the posterior hypothalamus. Inside vessel diameter, red blood cell velocity, and volumetric flow rate were recorded in response to electrical stimulations of varying magnitude in four series-coupled segments of the arteriolar network: 1A, 2A, 3A, and 4A. Systemic arterial pressure was also monitored. The vasoconstriction and flow reduction produced by stimulation of the lumbar chain was graded with the frequency of stimulation over the range of 0.5-16.0 Hz in all arteriolar segments. Examination of the relation between stimulation frequency and vasoconstrictor response measured as percent of control diameter indicated a sequence of responsiveness to peripheral stimulation where 4A = 3A greater than 2A = 1A. No changes in diameter were recorded in the venous microcirculation at any level of stimulation. Stimulation of the posterior hypothalamus with currents of 38-300 microA for 60 seconds produced graded vasoconstriction in only 3A and 4A vessels. Fluorescence histochemistry for biogenic amines was used to examine the distribution of innervation to the microvasculature. All segments of the arteriolar network from 1A to 4A possessed an adrenergic innervation; no vessels of the venous network were found to be innervated. The results indicate that the pattern of response of the arteriolar network in rat cremaster muscle to peripheral and central sympathetic stimulation is segmentally differentiated and consistent with the distribution of the vasomotor innervation.

Studies on the effect of heat treatment on the thrombogenicity of factor IX concentrates in dogs

This study examines the effects of heat treatment for 72 h at 80 degrees C on the potential thrombogenicity of lyophilized human coagulation factor IX concentrates. Since heating generated minor amounts of thrombin, concentrate was prepared with antithrombin III addition prior to heat treatment. Changes in coagulation parameters were followed prior to and after infusion of 100 iu/kg of heated and unheated concentrates to dogs. All batches produced a transient fall in platelet count during infusion and a delayed rise in plasma fibrinopeptide A, accompanied by a minor prolongation of the activated partial thromboplastin time. Such changes were less marked for heated batches. Control infusion of a 'failed' factor IX concentrate showed an additional fall in fibrinogen, rise in fibrin degradation products and a more rapid rise in fibrinopeptide A, while thrombin infusion caused an even more dramatic intravascular coagulation. These studies indicated no increase in the potential thrombogenicity of freeze dried factor IX concentrates as a result of heat treatment.

A pasteurised concentrate of human plasma factor XIII for therapeutic use

A therapeutic concentrate of factor XIII containing both A and B sub-units has been prepared from 300 kg pools of human plasma. The process starts from a cold-ethanol fraction from cryoprecipitate supernatant and therefore does not interfere with the recovery of other clinically valuable plasma proteins. Factor XIII is purified approximately 600-fold from plasma by precipitation with sodium citrate and by the removal of fibrinogen by brief heating. The product has been pasteurised in sorbitol solution to inactivate blood-borne viruses, ultrafiltered to remove sorbitol, adsorbed with bentonite and freeze-dried in a formulation meeting requirements for intravenous injection.

Heat-treated NHS factor VIII concentrate in the United Kingdom--a preliminary study

Three patients who have been given intermediate purity NHS heat-treated factor VIII concentrate have been followed prospectively for 7-10 months. None had previously received more than six donor units of blood products containing factor VIII. There were no clinical side effects from concentrate administration, haemostasis was satisfactory and no patient developed clinical or laboratory evidence of hepatitis or HTLV III/LAV infection. Heat treatment resulted in the loss of slightly more than 20% of factor VIII activity but in vivo recovery of factor VIII and half disappearance times were within the expected range.

Wallace H. Carothers and Fundamental Research at Du Pont

In the Depression decade, the research group headed by Wallace H. Carothers made two discoveries-neoprene and nylon-that have had an enormous impact on E. I. du Pont de Nemours and industrial research generally. At the same time, Carothers's many publications helped establish the foundations of polymer science. A theoretical organic chemist, he left Harvard University to take part in Du Pont's new fundamental research program. Although founded on the academic model, it soon began to reflect its industrial setting. Some surprising experimental results, the research philosophy of a new research director, and the economic realities of the Great Depression pushed Du Pont's pure scientists toward more practical or mission-oriented goals. Nylon and neoprene emerged from this creative tension between chemists interested in science and management committed to innovation.

A pasteurized antithrombin III concentrate for clinical use

A method for large-scale production of a pasteurized antithrombin III (AT III) concentrate for therapeutic use has been adapted from published methods. It includes the following steps: (1) batchwise adsorption onto heparin-Sepharose from plasma depleted of cryoprecipitate and prothrombin complex; (2) chromatographic elution at high salt concentration; (3) pasteurization for 10 h at 60 degrees C in the presence of added citrate ion; (4) desalting on Sephadex G-25, and (5) sterile filtration and freeze-drying. Seven batches prepared in this manner gave a mean yield of 269 U AT III/kg plasma. The product passed all the usual animal safety and pyrogenicity tests and has been used successfully in several courses of treatment of congenital deficiencies.