Coagulation Technique Research Articles

Possibilities for ocular vessel coagulation (author's transl)

Present-day possibilities of influencing pathological ocular vessels using an argon laser are presented. A distinction is made here between indirect methods such as area coagulation and direct methods with which specific vessels are treated. Whereas clinical tests involving vessel coagulation with pigmented epithelium absorption have already been carried out more or less successfully, selective vessel coagulation with hemoglobin absorption is still largely at the experimental stage. Our own experiments on animals have shown, however, that with the selection of a suitable coagulation technique and the use of suitable exposure parameters, vessel occlusion can be induced with the argon laser. To achieve this, shortening of the exposure times is particularly necessary.

Evidence against Vitamin K Deficiency in Normal Neonates

Umbilical cord plasmas from 24 normal full-term neonates were studied. We confirmed the prolonged prothrombin time and low levels of Vitamin K dependent clotting factors previously described (1), but using a number of recently developed immunological and coagulation techniques we could find no evidence of vitamin K deficiency. We conclude that the decreased levels of vitamin K dependent clotting factors of normal neonates are the result of decreased synthesis by the immature liver and that it is questionable whether vitamin K prophylaxis is necessary for these infants.

Dorsal root entry zone lesions for pain relief

✓ Arm pain due to avulsion of the cervical dorsal roots of the brachial plexus may become intractable, ameliorated little, if at all, by contemporary medical or surgical treatment. Severe and sudden trauma to the neck, shoulder, or arm is the usual cause of avulsion of the cervical rootlets. The injury may result in complete sensorimotor paralysis of the involved extremity, or a partial deficit if only a few rootlets are involved. Previous therapies have included stellate block, sympathectomy, high cervical cordotomy, rhizotomy, transcutaneous stimulation, dorsal column stimulation, mesencephalic tractotomy, cingulotomy, and the use of narcotics. The extent of the pathological change in the spinal cord following root avulsion is not completely known; at the time of operation, abnormalities frequently noted included ipsilateral atrophy of the dorsal aspect of the cord, dense arachnoid scarring, microcyst formation, and loss of both dorsal and ventral roots. The cervical myelogram is abnormal, although not necessarily pathognomonic of the extent of injury. The surgical technique of coagulation of the dorsal root entry zone is discussed, and the results and morbidity in 21 patients are reviewed. Thirteen patients (67%) continue to have good pain relief, with follow-up periods ranging from 6 months to 3½ years. Three patients with extremity pain from other causes are included in the series. Clinical observations suggest the possibility that pain resulting from brachial plexus avulsion originates from pathophysiological changes in the injured dorsal horn of the spinal cord. This report is a discussion of a new technique aimed at destruction of the dorsal root entry zone for relief of chronic extremity pain.

So-Called Facet Denervation in the Management of Intractable Back Pain

Attempted denervation of the zygapophyseal joint with radio-frequency coagulation techniques has been proposed as a method for treatment of pain of spinal origin. This study reports an appraisal of the method as applied to 149 patients selected from a population of 234 individuals with intractable spinal pain. Those selected for radiofrequency coagulation were patients who obtained temporary relief from local anesthetic blockade of the zygapophyseal joints. An overall 40% of patients achieved satisfactory relief from the “denervation.” In those with no prior spinal surgery, 61% were improved by the method. Only 26% of those having had prior surgery claimed benefit. Follow-up time ranged between 6 and 30 months.

Adsorption of Tryptophan onto Calcium Carbonate Surface

Adsorption of tryptophan onto CaCO3 at constant ionic strength (0.05 M Nacl) and from dilute aqueous solution (10(-4) M to 10(-3) M tryptophan) is reported. Adsorption was primarily determined by the charge characteristics of both the adsorbate amino acid and adsorbent CaCO3. When both adsorbate and adsorbent are semicharged, tryptophan ions are expelled away from the CaCO3-solution interface. Tryptophan is only removed by CaCO3 in a narrow pH range, 6.0 greater than pH less than 8.5 within which CaCO3 has positive charges, and tryptophan is negatively charged. The pH of zero point of charge, pHzpc, of CaCO3 was also determined by alkalimetric tritration and coagulation techniques and a value of 9.50 +/- 0.5 was found. These preliminary finding demonstrate primarily that interfacial chemical reactions play an important role in the temporal and spatial transformation of dissolved organic matter in natural water systems.

Tissue factor activity in lymphocyte cultures from normal individuals and patients with hemophilia A.

The procoagulant material of lymphocytes has been characterized as tissue factor. Lymphocytes stimulated with phytohemagglutinin or the purified protein derivative of the tubercle bacillus developed procoagulant activity with incubation in tissue culture. While this material corrected the prolonged clotting time of factor VIII (AHF) deficient plasma, we have shown, utilizing a sensitive radioimmunoassay, that no AHF antigen was present in the cell cultures. Further, we have demonstrated this material to be tissue factor by coagulation techniques and immunological cross-reactivity. The published data regarding factor VIII synthesis is reviewed in light of these observations and comments are made regarding the role of the lymphocyte procoagulant.

Von Willebrand's disease type B: a newly defined bleeding diathesis.

Summary: A patient with a lifelong bleeding diathesis is described. Studies of haemostatic function revealed a prolonged bleeding time and reduced glass bead adhesiveness. All other routine studies of haemostatic function yielded normal results, in particular the Factor VIII level, estimated both by antibody and coagulation techniques. Ristocetininduced platelet aggregation was absent and could be corrected by the addition of plasma or serum from normal controls or haemophiliacs, but not from patients with Von Willebrand's disease. It is apparent that the Von Willebrand plasma factor is either reduced in amount or inactive in this patient without an accompanying reduction in the Factor VIII level. It is postulated that Factor VIII may have two separate sites of biological activity, one concerned with the intrinsic pathway of coagulation and the other with platelet glass bead adhesiveness and skin bleeding time. It is proposed that this patient possesses a specific abnormality in the latter site, in contradistinction to the specific defect in the site concerned with intrinsic coagulant function in haemophilia.

Factor 8 on the vascular intima: possible importance in haemostasis and thrombosis.

THE site of factor VIII (anti-haemophilic factor) in tissues is uncertain. Clinical observations have suggested that it is associated with the reticuloendothelial system1,2 and in experimental studies it has been shown to be released from perfused liver, spleen and kidney3,4. Pool5 detected it only in the spleen by coagulation techniques. It is also thought to be present in cultures of peripheral blood leucocytes and skin fibroblasts6,7, and factor VIII-like material has been extracted from the kidney8. In all these studies factor VIII has been detected by coagulation techniques but the development of immunological methods has offered a potentially more specific and sensitive approach. We have used a factor VIII inhibitor neutralization technique to demonstrate the presence of factor VIII antigen in washed crude homogenates of liver, spleen and kidney9. This work has now been extended, by using immunohistological studies with fluorescein-conjugated antisera. These indicate the presence of factor VIII on the vascular intima of many organs and in the mononuclear cells of the spleen. The results may be of importance for studying not only the physiology of haemostasis but also the pathogenesis of thrombosis.

A technique of tissue coagulation by microwave

A technique of tissue coagulation by microwave

Reduction of energy in photocoagulation with the Zeiss-Oberkochen Xenon-Are Apparatus. II. Application of short-pulse, small-spot technique to humans.

A short-pulse, small-spot xenon arc coagulation technique, worked out on rabbits as described in a preceding paper, has been applied to humans with good results. The lesions can be made to resemble in most respects to those generated by weak ruby laser pulses, insofar as the choroid and the nerve fiber layer are not damaged, resorption of edema is rapid and pigment proliferation abundant. The technique consists in superposing the cathode hot-spot of the xenon arc by its mirror image, using small field stops and electronically controlled exposure times of typically 0.1 sec. The apparatus used was the photocoagulator of Zeiss-Oberkochen equipped with the optical attachement which allows of working with the Goldmann contact glass. Detailed description of some cases treated illustrates this method.

Stability of ferric oxide hydrosols

Ferric oxide hydrosols are composed of a haematite core surrounded by an hydrated oxide shell. Interactions have been studied, on both sides of the p.z.c., between ferric oxide surface and a series of anions and cations having characteristics ranging from structure promoters to structure breakers. Although ferric oxide has a moderate crystalline field, the observed adsorption sequences show that the interface acts as a structure promoter for water molecules. The large spreading of the measured adsorption sequences, especially at extreme pH values, proved the coagulation technique to be a good tool for the study of ion-surface interactions. A new type of behaviour has been observed; at low surface potentials the ions behave as indifferent but at higher surface potentials they are specifically adsorbed.

COAGULATION TESTING: A COMPARISON OF TECHNIQUES—PART II

Coagulation to remove particulate matter from turbid waters may be carried out by any of several techniques. This report attempts to discover which coagulation techniques yield comparable results, and which of these is preferable from the operator's standpoint. Because of its length, this report is divided in half. Part I appeared in last month's issue.

COAGULATION TESTING: A COMPARISON OF TECHNIQUES—PART 1

Coagulation to remove particulate matter from turbid waters may be carried out by any of several techniques. This report attempts to discover which coagulation techniques yield comparable results, and which of these is preferable from the operator's standpoint. Because of its length, this report is divided in half. Part II, containing the results and a discussion, will appear in next month's issue.

Control of bleeding by silk ligation and diathermy coagulation during tonsillectomy: A comparison of efficacy of the two techniques in the first 24 hours after surgery.

Objective:To assess and compare the relative efficacy of silk ligation and diathermy coagulation techniques in controlling bleeding during tonsillectomy in the first 24 hours.Methods:This prospective study was conducted at the Department of ENT, Khalifa Gul Nawaz Teaching Hospital, Bannu and this department related consultants’ private clinics from January 1, 2012 to December 31, 2014. The study included 180 cases. All patients included were having history of recurrent, acute tonsillitis, with more than 6–7 episodes in one year, five episodes per year for two years, or three episodes per year for three years. All the surgeries were performed by dissection method. Haemostasis during the procedure was secured by either ligation with silk 1 or using diathermy. The results were analyzed using SPSS 16.0 for windows.Results:A total of180 cases were included in the study. The ages of the patients ranged from 5 to 40 years with the mean age of 15.56 years and a std.deviation of +/- 8.24. The male to female ratio was 1.25:1. The number of hemorrhages occurring was greater in the ‘diathermy coagulation’ group as compared to the ‘silk ligation’ group. However, the observed difference was statistically insignificant (p >.05).Conclusion:Primary haemorrhage occurring during tonsillectomy is a serious threat and control of bleeding during the procedure should therefore be meticulous. Both suture ligation and coagulation diathermy for control of bleeders during the procedure by dissection method are equally effective.

Determination of Temik Residues in Raw Fruits and Vegetables

Abstract Temik, 2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl)oxime, is a systemic pesticide effective both by topical application to the plant and by systemic translocation from treated soil. The method developed for residues of Temik in crops is based on extraction of the crops with chloroform, followed by cleanup involving both coagulation and liquid partitioning techniques. The analysis involves both base- and acid-catalyzed hydrolysis to liberate hydroxylamine, which is then oxidized by iodine to nitrous acid; the latter is determined by diazotization (a modification of the Griess test for nitrites). The method is sensitive to about 0.03 ppm; average recovery from 8 crops is 96.3 ± 3.2%. Other current commercial pesticides do not interfere in the analysis.

Organic constituents of gelatins and glues. I.‐Heat‐coagulable mucoprotein components from gelatins

AbstractComponents isolated from acid and lime processed gelatins by a heat denaturation and coagulation technique are shown to be mucoproteins contaminated with smaller amounts of gelatin and lipid, and probably having their origin in the alkali‐soluble mucoproteins of the connective tissues used for the manufacture of the gelatins. Differences in amino‐acid composition of the isolated materials are noted. From comparisons of these with materials isolated by other techniques it is concluded that at least two types of mucoproteins are found in gelatins; one of these originates from the alkali‐soluble mucoproteins of the connective tissues and the other from materials similar to the acetic‐acid‐soluble fraction from connective tissue not precipitated by NaCl.

Some practical aspects of anticoagulant therapy.

ANTICOAGULANT therapy at the Royal Victoria Hospital in Montreal is directed by the personnel of the hematology service. Certain technicians are highly trained in coagulation techniques and perform the prothrombin and clotting determinations. The hematologist in charge of anticoagulant therapy not only supervises the laboratory tests but is continually aware of the clinical condition of the patient; he advises as to initiation and cessation of anticoagulant therapy, selects the anticoagulants to be used, and orders their daily dosage. This has resulted in extensive experience in the clinical and laboratory aspects in managing a wide variety of patients. As a prerequisite to starting anticoagulant therapy, each patient is assessed clinically as regards indications and contraindications, and preliminary hematologic studies are performed as indicated. Heparin is usually administered intravenously every four hours. The three-tube modified Lee-White clotting time is performed initially, two and one-half hours after the first heparin injection and twice