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Biomedical subjects

M J Reardon

Publications and source records attributed to M J Reardon.

At least 91 records · Page 5Linked to original sources
PubMed1989

Effectiveness of WR 163577 against animal trypanosomes in goats and mice.

A bisquinaldine, 1,6-bis-(6-amino-2-methyl-4-quinolylamino) hexane, was tested against Trypanosoma brucei ssp. in goats and against T. brucei, T. congolense and T. vivax in mice. At doses of 25 and 100 mg kg-1, the drug protected goats for at least 90 days against blood challenge with T. brucei ssp. Fifty to sixty per cent of goats challenged 180 days after treatment were protected, but all goats challenged 270 days after treatment became infected. In mice, bisquinaldine also had a marked effect on T. brucei, but only a minimal effect on T. vivax and no apparent effect on T. congolense. No drug toxicity was noted in mice even at doses of 2000 mg kg-1. Both a short-term (25 and 100 mg kg-1) and long term (100 mg kg-1) toxicity was apparent in goats treated with bisquinaldine.

Aminoquinolines↗
PubMed1989

Trypanosoma vivax: disseminated intravascular coagulation in cattle.

Five crossbred cattle infected with Trypanosoma vivax (Likoni) by Glossina morsitans developed capillary haemorrhages at the onset of parasitaemia, followed by the presence of occult blood in faecal samples and eventually melena. Two animals required treatment to survive, on days 13 and 38 respectively. The other three animals cleared their parasitaemias without treatment. Packed cell volume (PCV) levels decreased in all animals to levels ranging from 7.5 to 17%. Relapse in a treated animal initiated marked haemorrhage and a loss of 14 PCV units during a six-day period. Thrombocytopenia was common to all animals, and thrombocytes decreased to levels of 4000/microliters of blood. All animals developed increased levels of fibrinogen and fibrin monomer. Prolonged prothrombin times were found in all animals, and activated partial thromboplastin times were also extended in the two animals with high parasitaemias.

Anemia↗
PubMed1989

Natural and acquired resistance to Trypanosoma vivax in cattle.

Zebu x European (Z x E) crossbred cattle suffered a more severe course of disease than Boran cattle when infected with Trypanosoma vivax (Likoni) by Glossina morsitans. All Z x E animals in this study required Berenil treatment while all Borans self-cured the infection without treatment. The more severe disease in Z x E animals was characterized by longer periods of patent infection and fever, more severe anaemia and greater likelihood of haemorrhage. Cattle previously infected and cured with Berenil showed resistance and self-cured challenge infections. After self-cure cattle remained immune to tsetse fly challenge with the homologous trypanosome stock for long periods. Immunity induced by infection and drug or self-cure appeared to be specific for the homologous stock, since cattle immune to T. vivax (Likoni) showed no resistance when challenged with stocks of T. vivax isolated in Lugala, Uganda or Galana, Kenya. Severe haemorrhages, most prominent in the digestive tract, were seen in some infected cattle before treatment.

Animals↗
PubMed1989

Effects of splenectomy on Trypanosoma congolense infection in cattle.

The role of the spleen in cattle infected with Trypanosoma congolense was studied by comparing levels of parasitaemia, blood cell values, and body weights of intact and splenectomized cattle. A total of 28 Zebu x Hereford steers were used in two separate experiments. Seven animals were splenectomized at least four weeks prior to infection and two others were splenectomized 128 days after infection. Splenectomized animals were compared to 12 intact infected animals and seven intact uninfected controls. The splenectomized animals suffered no less severe anemia and no higher parasitaemia than the intact, infected cattle. Splenectomy in two animals during infection had no effect on packed cell volumes, parasitaemia or survival. Splenectomized cattle have lower levels of circulating lymphocytes following treatment than intact animals; also, the splenectomized steers lost more weight during the active infection.

Animals↗
PubMed1987

Atrial rupture in a child from cardiac massage by his parent.

A 4-year-old boy presented with a single seizure following a viral syndrome. He had a pericardial effusion on admission, and this increased suddenly on the third day of hospitalization, producing cardiac tamponade. After blood was aspirated from the child's pericardial cavity, the father revealed that he performed cardiac massage on his son following the seizure. A laceration of the right atrium was repaired at operation, and the boy made a good recovery. Cardiopulmonary resuscitation by lay persons is not without hazard, and patients with such a history should be watched carefully for the possibility of damage to intrathoracic structures.

Cardiac Tamponade↗
PubMed1986

Hemodynamic compromise (tricuspid stenosis and insufficiency) caused by an unruptured aneurysm of the sinus of Valsalva.

A patient is described with an unruptured aneurysm of the noncoronary sinus of Valsalva that occupied the right ventricular inflow tract and caused dynamic tricuspid stenosis and insufficiency. Results of two-dimensional echocardiography delineated the anatomy of the aneurysm and pulsed Doppler examination provided evidence that the aneurysm was unruptured. The unruptured aneurysm was resected successfully.

Adult↗
PubMed1986

Surgical repair of aneurysms involving the distal aortic arch.

The surgical approach to aneurysms involving the transverse aortic arch usually requires either techniques for perfusion or hypothermic circulatory arrest. A simplified approach may be warranted when the aneurysmal process begins in the distal aortic arch and spares the innominate artery. Between November, 1975, and January, 1984, 32 patients (22 men, 10 women; median age 61 years) underwent repair of aneurysms of the distal aortic arch by simple cross-clamping of the diseased aortic segment. In each, the aneurysm arose distal to the innominate artery and involved the arch at the origin of the left subclavian or left common carotid artery. Proximal control was achieved by cross-clamping the aortic arch between the innominate and left carotid arteries. No shunts or extracorporeal bypass circuits were employed. Proximal hypertension was controlled by sodium nitroprusside infusion. All patients were heparinized. A mean aortic cross-clamp time of 27 +/- 10 minutes was required for Dacron graft replacement in 28 patients and Dacron patch repair in three patients. Surgical repair was accomplished successfully in 32 patients. The 30 day mortality was 3% with an in-hospital mortality of 6%. There were no complications as a result of myocardial infarction or stroke. Paraplegia (three patients) was related to cross-clamp time (less than 30 minutes, 0/18; greater than 30 minutes, 3/13 [p less than 0.001]) and distal extent of the aneurysm (localized, 0/22; extensive, 3/9 [p less than 0.001]). Transient renal failure (two patients) was related to cross-clamp time (less than 30 minutes, 0/18; greater than 30 minutes, 2/13 [p less than 0.001]). This experience supports the use of simple aortic cross-clamping for aneurysms of the distal aortic arch, especially if an expeditious repair can be accomplished.

Acute Kidney Injury↗
PubMed1985

Total anomalous pulmonary venous return: report of 201 patients treated surgically.

Between 1956 and June 1984, 201 patients with uncomplicated total anomalous pulmonary venous return (TAPVR) were operated on at the Texas Heart Institute and Texas Children's Hospital. Two groups were previously reported that included periods from 1955 to 1964 and from 1964 to 1972. From 1972 until 1984, 76 patients were operated on for uncomplicated TAPVR. The mortality was 11/19 (57%) for patients less than 1 month old, 2/27 (7%) for patients 1 month to 1 year old, and 0/21 (0%) for patients older than 1 year. Forty-five percent (5/11) of the infants who died in the less than 1-month-old category were operated on when they were less than 24 hours old and in extremis when presented for correction.

Journal Article↗
PubMed1985

Human cardiac explantation and autotransplantation: application in a patient with a large cardiac pheochromocytoma.

A rare paraganglioma of the chromaffin type, located intrapericardially, was removed from a 42-year-old man by autotransplantation of the heart. Although the results were unfavorable in this case, the technique of autotransplantation deserves consideration in resecting large tumors that encroach upon the heart. To our knowledge, this technique has not been previously used for surgical excision of cardiac tumors.

Journal Article↗
PubMed1984

A complement fixation test for visceral leishmaniasis using homologous parasite antigen II. Results in an endemic area in Kenya.

Further studies of the complement fixation test using homologous parasite antigen in an endemic area for visceral leishmaniasis have showed that 82% of individuals with proven visceral leishmaniasis were positive initially whilst 92% were positive at some stage during their illness. Titres fell slowly following effective treatment and anticomplementary activity, confined to confirmed visceral leishmaniasis, was usually lost during treatment. Individuals with alternative causes of hepatosplenomegaly from the same population were negative apart from those with a presumptive diagnosis of visceral leishmaniasis but without parasitological confirmation. Less than 1% of people in the same endemic area without visceral leishmaniasis were positive, suggesting that preliminary serodiagnostic investigation would limit the need for invasive investigation under field conditions.

Adolescent↗
PubMed1984

Interrupted aortic arch: brief review and summary of an eighteen-year experience.

Interrupted aortic arch (IAA) is an uncommon congenital anomaly representing approximately 1% of congenital heart disease. More than 97% of the cases also have associated cardiac anomalies complicating their treatment. Because the median age at death in untreated cases is 10 days, this condition usually occurs as a complicated neonatal surgical emergency. There are three types of IAA: Type A is interrupted distal to the left subclavian artery. Type B, which is the most common form, is interrupted between the left common carotid and the left subclavian arteries. Type C, which is the most uncommon type, is interrupted between the innominate and left common carotid arteries. Since the first patient with this congenital anomaly was treated at our institution in 1965, 39 patients have undergone surgical treatment. Two of these (4.6%) had no associated intracardiac lesions, and both survived bypass grafting without complications. There were 12 Type A (30%), 26 Type B (67%) and one Type C (3%). A variety of individualized techniques were used to repair the defects. The three basic techniques were (1) direct aortic to aortic anastomosis bridging the gap, (2) "turndown" or "turnup" of one of the arch vessels to the aorta across the gap, or (3) bypass of the interruption with graft material. Because aortic arch and associated cardiac anomalies represent a neonatal surgical emergency, our therapeutic plan consists of treatment for biventricular failure and PGE(1) infusion to maintain ductal patency, and surgical correction as soon as feasible.

Journal Article↗
PubMed1981

An analysis of the isoenzymes of creatine phosphokinase and lactic dehydrogenase in the esophagus.

Surgical manipulation of muscular organs can cause alterations of the serum isoenzymes of creatine phosphokinase (CPK) and lactic dehydrogenase (LDH), which are frequently used to confirm the diagnosis of myocardial infarction (MI). Since the content of these enzymes and their isoenzymes has not been established for the esophagus, an experiment was conducted to evaluate and compare the enzymes in postmortem specimens from humans and fresh canine specimens. One gram transmural esophageal sections were taken from specimens having no demonstrable disease. All samples were homogenized individually in Ringer's lactate solution and centrifuged, and the supernatants were analysed for the respective isoenzyme distributions by agarose gel electrophoresis. From the study we drew the following conclusions: (1) all three isoenzymes of CPK (including CPK-MB, the myocardialisoenzyme) are present in the esophagus; (2) LDH, the isoenzyme of LDH most prevalent in myocardium, is the least common of the five isoenzymes of LDH in the esophagus; (3) the dog is an appropriate model for studying changes of these isoenzymes after operation; and (4) any potential confusion in diagnosing postoperative MI due to esophageal CPK-MB in the serum can be resolved, theoretically, by analyzing LDH serum isoenzymes. In myocardial infarction, LDH becomes the predominant isoenzyme, whereas esophageal injury should be associated, theoretically, with a serum LDH isoenzyme pattern in which LDH is the least prevalent isoenzyme.

Adult↗
PubMed1981

Acute experimental canine ehrlichiosis. I. Sequential reaction of the hemic and lymphoreticular systems.

Dogs with acute Ehrlichia canis infection showed the established clinical features of acute ehrlichiosis and had thrombocytopenia, anemia, increased serum glutamic pyruvic transaminase activity, and decreased total serum protein and albumin concentrations during the first weeks after infection, and increasing gamma globulin concentrations after the third week. Gross lesions in hemic and lymphoreticular tissues were transient lymphadenomegaly, splenomegaly, and increased red long-bone marrow. Lymphoreticular hyperplasia in the paracortical area of lymph nodes and in the splenic red pulp occurred during the second week of infection. Later, small lymphocytes were replaced by medium-sized lymphocytes and plasma cells. Activity of germinal centers increased initially, as shown by numerous mitotic figures and macrophages, but diminished later, and the follicles blended with interfollicular and paracortical tissue because of a decrease in small lymphocytes in the mantle layer. We saw splenic hemorrhages near the perifollicular sinus, and vasculitis, most often phlebitis, in the kidney between weeks 2 and 4. Multifocal reticuloendothelial hyperplasia occurred in the liver during the early stage and injured adjacent hepatocytes by compression. Lesions typical of ehrlichiosis in these dogs were interstitial pneumonia, subendothelial aggregates of mononuclear cells in pulmonary blood vessels, renal periglomerular and perivenular plasmacytosis, hemopoietic hyperplasia, and perivascular cuffs of lymphocytes and plasma cells in many organs.

Acute Disease↗
PubMed1981

Acute experimental canine ehrlichiosis. II. Sequential reaction of the hemic and lymphoreticular system of selectively immunosuppressed dogs.

The lymphoreticular response of dogs to Ehrlichia canis infection was studied after immunosuppressive therapy with cyclophosphamide or antilymphocyte serum. Immunosuppression did not increase mortality, nor did it prevent or significantly modify the clinical manifestations of acute ehrlichiosis. The clinical, hematologic and serum biochemical characteristics of acute ehrlichiosis appeared seven or more days later in immunosuppressed than in immunologically intact infected dogs. Immunosuppressive therapy generally attenuated the lesions of acute ehrlichiosis. Lymphoreticular tissues were partially depleted of lymphocytes, as would be expected following cyclophosphamide therapy, but the hemopoietic tissue of cyclophosphamide-treated principals was much more cellular than that of the controls, perhaps demonstrating a direct stimulatory effect E. canis infection on bone marrow. Antilymphocyte serum therapy reduced cellularity of the thymic-dependent areas in both the spleen and lymph nodes, but B-cell areas were not affected. The B-cell areas did not increase in activity during infection in the antilymphocyte serum-treated dogs, suggesting the need for an intact T-cell compartment for the lymphocytic proliferation that occurs in nonsuppressed infected dogs. Renal vasculitis and lympho-plasmacytosis were absent and the pulmonary and hepatic lesions were not as pronounced in the dogs given antilymphocyte serum as in immunologically competent infected dogs.

Animals↗
PubMed1981

Changes in serum total creatine phosphokinase (CPK) and its isoenzymes caused by experimental ligation of the superior mesenteric artery.

The changes in serum total CPK and its isoenzymes have not been delineated in acute mesenteric infarction. As measurement of serum CPK levels could conceivably be a useful diagnostic test for bowel infarction, this experiment was performed to assess changes in serum CPK levels in bowel infarction in dogs, using sham operation and talc peritonitis as controls. Laparotomies were performed in 20 dogs, and each was as signed randomly to one of three groups: those having laparotomy (LAP), talc peritonitis (PER), and superior mesenteric artery infarction (MAI). Mixed venous blood samples were obtained from all subjects for 30 hours after surgery. All animals were killed, and complete autopsies were performed. Confirmation of infarction and determination of its extent were obtained through both gross and microscopic examination of the gut in canines subjected to arterial infarction. Total serum CPK levels were determined by spectrophotometric analysis. Agarose gel electrophoresis was used to determine the levels of each of the isoenzymes. Significant elevations of CPK and CPK-MM occurred nine hours after injury. CPK-BB reached maximum elevation by six hours, while CPK-MB did not reach its maximum until 24 hours after injury. From data in the study we conclude that total CPK and its isoenzymes become elevated in the serum of canines subjected to experimental superior mesenteric artery infarction. That CPK-BB elevations peak in the first 12 hours after injury and CPK-MB in the second 12 hours after injury may be of particular diagnostic significance.

Animals↗
PubMed1979

Serum electrophoretic patterns of karyotypically defined owl monkeys (Aotus trivirgatus).

Sera were electrophoretically separated and examined from 238 karyotyped Aotus trivirgatus and 29 unkaryotyped offspring. Albumin polymorphism was observed with high frequency and found to conform to a codominant allele mode of transmission. A unique alpha globulin was identified in Karyotypes I, VII and unkaryotyped offspring, of which one parent was a Karyotype I. This alpha globulin phenotype appears to be a dominant characteristic.

Alpha-Globulins↗