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Biomedical subjects

J W Pate

Publications and source records attributed to J W Pate.

At least 55 records · Page 3Linked to original sources
PubMed1988

Investigation of passive venovenous shunts during the anhepatic period of canine hepatic transplantation.

The anhepatic period of canine orthotopic hepatic transplantation is usually accompanied by cardiovascular instability due to occlusion of both the portal and inferior systemic venous systems. The present study was undertaken in order to determine some of the hemodynamic and renal alterations that occur during a 2 hour anhepatic period in the dog and to investigate the use of a passive endoportal, endocaval venovenous shunt that places both the portal and infrahepatic vena caval limbs of the shunt directly into the divided ends of these vessels. Three groups of experimental animals were studied. One group had hepatectomy without a shunt and was compared with two other groups which had hepatectomy with some form of venovenous shunting. Systemic arterial blood pressure, portal and inferior vena caval pressure, urinary output, and renal histology were all better maintained when a shunt was used.

Animals↗
PubMed1988

Mechanism of calcium and magnesium translocation in acute pancreatitis: a temporal correlation between hypocalcemia and membrane-mediated excessive intracellular calcium accumulation in soft tissues.

Hypocalcemia frequently occurs in acute pancreatitis (AP), but its pathogenesis remains unknown. Since AP is often accompanied by acute alteration in the structure and function of cellular membranes, we investigated whether hypocalcemia associated with AP can be explained by acute translocation of Ca from extracellular to intracellular compartments. AP was induced in dogs by injection of autologous bile into the pancreatic duct, and in rats by controlled infusion of artificial bile containing Na-taurochlorate, Keflin, and trypsin into the cannulated bile duct. Plasma Ca, Mg, amylase, and PTH concentrations were determined in the serial samples. Tissue [Ca] and [Mg] were determined in pancreas, liver, kidney, and abdominal wall muscle biopsies obtained immediately before and 24 h after induction of AP in dogs or 2 h following induction of AP in rats to evaluate the temporal correlation between hypocalcemia and excessive intracellular Ca accumulation in soft tissues. Hypocalcemia (p less than 0.001) and hyperamylasemia (p less than 0.01) occurred within 6 h of AP in dogs, and persisted throughout. Plasma [Mg] was lowered and PTH activity was elevated at 6 and 18 h, and returned to a near normal level by 24 h. Concomitant with persisting hypocalcemia and lower ultrafilterable plasma [Ca2+], tissue [Ca] was significantly elevated in pancreas (71%), liver (24%), and abdominal muscle (112%), but was depleted in kidney by 25%. Pancreas biopsy following AP revealed histological signs of fulminant pancreatitis. [Mg] was depleted only in the pancreas (18%) and remained unaltered in other tissues. No significant changes were noted in the sham-operated animals. The observed temporal correlation between profound hypocalcemia and acute excessive intracellular Ca accumulation in soft tissues strongly suggests that hypocalcemia in AP may be precipitated by leaky-plasma-membrane-mediated excessive intracellular Ca accumulation. Similar data together with significantly reduced cellular energy charge (p less than 0.01) obtained from AP rats provided additional support to our hypothesis.

Acute Disease↗
PubMed1987

Electrocardiographic, biochemical, and morphologic abnormalities in dystrophic hamsters with cardiomyopathy.

Electrocardiographic (EKG) changes were investigated in 7-month-old dystrophic hamsters (DH) with cardiomyopathy and were correlated with biochemical and histologic aberrations. Abnormally tall R-I and R-aVL amplitudes, deep S-III and S-aVR waves, and elongated PR-I, QT-I, and QRS-I intervals (all at P less than 0.0001) were noted in DH compared with normal hamsters. These EKG changes are similar to those seen in Duchenne muscular dystrophy (DMD) and support cardiac hypertrophy (P less than 0.001) in DH. Excessive intracellular calcium accumulation in the heart (P less than 0.0001), diaphragm (P less than 0.001), and rectus femoris (P less than 0.05), and elevated plasma creatine kinase concentrations (P less than 0.001) were also noted in DH. Histopathology in the cardiac and skeletal muscles of DH included fatty infiltration, centronucleation, and sporadic necrosis with calcium deposition. Observed EKG abnormalities, biochemical alterations, and histological aberrations in the cardiac and skeletal muscles of DH are strikingly similar to those reported in DMD and thus substantiate the relevance of DH as a suitable model for the study of muscular dystrophy and cardiac hypertrophy.

Animals↗
PubMed1985

Traumatic rupture of the aorta: emergency operation.

Fifty-nine patients who had traumatic aortic rupture in the area of the isthmus and were treated less than one week after injury were studied. Most patients (N = 47) underwent repair using pump-oxygenator partial bypass; 7 had simple cross-clamping. Paraplegia developed in 4 during operation. One patient died of a head injury after receiving heparin for bypass. The experience with these patients and a critical review of the literature indicate that the use of extracorporeal circulation and avoidance of hypoxia and hypercapnia may decrease the probability of paraplegia. When laparotomy preceded thoracotomy, there were no clearly deleterious effects of heparinization.

Accidents↗
PubMed1985

Soft tissue calcium and magnesium content in acute pancreatitis in the dog: calcium accumulation, a mechanism for hypocalcemia in acute pancreatitis.

The mechanism of hypocalcemia in acute pancreatitis remains unknown despite continued investigative work over the past several decades. Because acute pancreatitis is accompanied by multiple systemic manifestations and alterations of plasma membranes, the possibility that an abnormal translocation of calcium from extracellular to intracellular compartments could play a role in hypocalcemia of acute pancreatitis was investigated in dogs. Acute pancreatitis was induced by injecting bile into the pancreatic duct. Plasma calcium, magnesium, and amylase concentrations were determined. Calcium and magnesium contents were also measured in biopsy specimens of pancreas, liver, skeletal muscle, and kidney before and after induction of acute pancreatitis. As expected, hypocalcemia and hyperamylasemia occurred 6 hours after induction of pancreatitis, and persisted throughout the experiment, 13 to 25 hours. Plasma magnesium concentration fell at 6 and 18 hours, and returned to an almost normal level by the end of the study. A significant elevation in calcium content of pancreas (71%), liver (24%), and muscle (112%), and 25% reduction of calcium in kidney were observed in dogs with histologic signs of pancreatitis. However, tissue magnesium concentration fell in pancreas (18%) but remained unchanged in the other tissues investigated. No significant changes in any variables were detected in sham-operated animals. In another group of dogs in which the accessory pancreatic duct was not occluded when bile was injected, the histologic lesions were extremely mild, although the plasma calcium concentration and the pancreatic calcium and magnesium contents were altered just as much as in the severely affected dogs. Data suggest that the hypocalcemia of acute pancreatitis may be the result, at least in part, of accumulation of calcium in soft tissues. The decreased calcium content in kidney could be related to hypocalcemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Amylases↗
PubMed1985

Postsplenectomy complications.

Postsplenectomy complications were reviewed among 420 patients with simple splenic injury, splenic plus multisystem trauma, elective splenectomy, incidental or accidental splenectomy, and those having splenectomy prior to renal transplantation. Complications not specifically related to splenectomy occurred postoperatively in 52 per cent and 41 per cent, respectively, in the complex trauma and incidental-accidental splenectomy groups. Nonfatal complications specifically related to splenectomy occurred in 15 per cent of patients with multi-organ injury and in 18 per cent of patients with incidental-accidental splenic removal. Morbidity was infrequent when simple splenic trauma prompted splenectomy or in elective splenectomy. Mortality related to splenectomy occurred most often following renal transplantation, but also appeared high when the spleen was removed for multiple trauma or incidental to other surgery. The latter category is at risk for morbidity and mortality when splenectomy is incidental to a planned procedure (e.g., radical gastrectomy) or accidental as when injured by the surgeon. These splenectomies and those planned prior to transplantation may be unnecessary in many instances. The postsplenectomy sepsis syndrome was encountered late only once in this entire series; nonetheless, sound indications for splenectomy must prevail before splenic removal since significant early morbidity and mortality follows splenectomy.

Adult↗
PubMed1984

Lower esophageal ring: experiences in treatment of 88 patients.

The lower esophageal ring is an unusual clinical disorder of the esophagus and consists of a thin submucosal circumferential scar that forms in the lower esophagus. It is probably an acquired lesion resulting from repeated insults to the lower esophageal mucosa. The symptom of dysphagia results from esophageal obstruction, and the degree of obstruction is directly related to the internal diameter of the ring. Episodic aphagia results from impaction of food at the site of the ring. Since 1970, 88 patients have been seen with either dysphagia or episodic aphagia. Sixty-five with chronic limited reflux were treated primarily by oral dilation. Two of them required an antireflux procedure at a later date because of accentuation of reflux symptoms. Eighteen patients received surgical treatment initially because of severe reflux disease. Treatment consisted of interruption of the ring combined with an antireflux procedure. Five patients received no treatment. Lower esophageal ring may be managed satisfactorily through oral dilation, resulting in relief of dysphagia. If reflux disease is present or is accentuated by dilation and cannot be controlled medically, then the appropriate antireflux procedure should be done.

Adult↗
PubMed1984

Digital venous angiography. A prospective evaluation in peripheral arterial trauma.

Digital venous angiography (DVA), a new radiographic technique, was prospectively compared to conventional intra-arterial angiography (CA) in a group of 153 patients with trauma and suspected peripheral arterial injury ( PAI ). Criteria for entry included: large hematoma, proximity to a major vessel, shotgun wounds, blunt injury of the extremities, and fractures or dislocations of areas with high risk of arterial injury. Patients with unequivocal clinical evidence of PAI were excluded. Study patients had both DVA and CA. Sixteen injuries were diagnosed: lacerations (9), transection (1), AV fistulae (2), thromboses (2) and minute intimal flaps (2). All patients with abnormal studies were surgically explored; there were no false-positives. There were no known false-negatives with CA. The intimal flaps were not recognized initially on DVA and their clinical significance is questioned. DVA, compared to CA in PAI , had decreased patient discomfort, cost, and morbidity. It has the potential for study of multiple areas of the body from a single I.V. catheter. DVA can probably replace CA for civilian penetrating wounds. CA may remain the standard for blunt and high velocity injuries.

Adolescent↗
PubMed1983

Squamous cell carcinoma of the thoracic esophagus.

Carcinoma of the esophagus, the fourth most common malignant tumor of the gastrointestinal tract, still has a dismal outlook. Since July 1960, we have collected data on 642 patients with this lesion. Adenocarcinomas (which might arise from gastric mucosa) have been excluded. Almost one-fifth of the patients were far-advanced and inoperable when first diagnosed. Time between onset of symptoms and diagnosis was deemed excessive in over half of the patients; physicians frequently accounted for much of this delay. Preoperative diagnosis proved accurate in 99 per cent of the cases. Evaluations of direct extensions and distant metastases and attention to nutritional status correction were of prime importance. Operative technique and indications for surgery have become "standardized," and while surgical mortality has remained about 20 per cent throughout the period, morbidity has decreased steadily. Comparisons of irradiation and surgery in relation to palliation indicate that palliation is probably better in the surgically treated patient. However, it is emphasized that this comparison, as well as comparison of other results, is not scientifically valid since the groups of patients are not comparable due to clinical selection.

Carcinoma, Squamous Cell↗
PubMed1981

Clinical and laboratory evaluation of cefoperazone.

Cefoperazone, a third-generation cephalosporin derivative, has been reported to have excellent antibacterial activity against a wide range of gram-positive and gram-negative pathogens, including Pseudomonas aeruginosa. We treated 54 patients with a variety of clinical infections with cefoperazone and determined the susceptibilities of their 90 bacterial isolates. An additional 25 aerobic isolates obtained from patients treated with cefamandole in a comparison study were also tested for susceptibility to cefoperazone. Thus a total of 115 isolates were studied in vitro. One hundred nine (95%) of 115 bacterial isolates, including gram-positive and gram-negative aerobes and anaerobes, were susceptible to less than or equal to 32 microgram/ml. Only four isolates (three Escherichia coli and one Serratia marcescens) were highly resistant (minimal inhibitory concentration greater than or equal to 128 microgram/ml). We were able to assess clinical outcome of cefoperazone therapy in 53 patients; favorable responses (cure of improvement) were found in 48 (91%). P. aeruginosa was a major pathogen in three patients treated with cefoperazone; all three showed a favorable response. Side effects of cefoperazone therapy were noted in seven (13%) patients, and laboratory abnormalities were observed in 11 (20%) patients; all of these were mild and readily reversible. Cefoperazone thus appears to be safe, well tolerated, and suitable for use in a variety of human infections.

Bacterial Infections↗
PubMed1980

Penetrating wounds of the neck: explore or not?

While routine formal exploration for all neck wounds penetrating the platysma remains a safe policy, our experience indicates that it is not necessarily the best policy in large, well-staffed teaching hospitals with extensive trauma services. Careful and repeated physical examinations and observations supplemented by simple radiograph examinations allowed selection of a large group of patients who were satisfactorily treated by simple wound closure and clinical observations. Aggressive emergency room management and adequate exposure and repair of vascular injuries prevented cerebral damage so common in previous reports.

Angiography↗
PubMed1979

Symptomatic lower esophageal ring: treatment of 24 patients.

The lower esophageal ring, or Schatzki's ring, consists of a thin, submucosal, circumferential scar which forms a thin incomplete diaphragm in the lower esophageal lumen. The symptoms may be either episodic aphagia or progressive dysphagia, and the severity of symptoms is related to the diameter of the ring. Between 1970 and 1978, we saw 24 patients with lower esophageal rings and complaints of episodic aphagia or progressive dysphagia. Symptoms of esophagitis were present in 20 of the 24. Twenty were treated surgically by interrupting the rings and repairing the sliding hiatal hernias. Two were treated by dilatation and two received no treatment to the ring. Hiatal hernias have recurred in two patients. In one, there is a recurrent ring and in the other, an acid peptic stricture. The ring has responded to dilatation and the peptic stricture to dilatation and repair of the recurrent hernia. Two patients without symptoms of esophagitis, treated by dilatation, are doing well but the follow-up period is so far too short to draw any conclusion.

Aged↗
PubMed1979

Peripheral pulmonary embolization from central pulmonary aneurysm.

A 59-year-old man underwent successful repair of a pulmonary arterial aneurysm because of peripheral pulmonary embolization. These lesions are relatively rare; and, to out knowledge, peripheral embolization from such an aneurysm has not been previously reported.

Aneurysm↗
PubMed1977

Present status of coronary artery surgery.

Postinfarction ventricular septal defects are best repaired surgically several weeks after occurrence; however, deterioration of the patient's condition may require emergyncy operation. Ventricular aneurysms are resected when associated with low cardiac output, emboli occur or when present in a patient who is otherwise a candidate for aortocoronary grafting. Mitral valve replacement may be required when coronary disease produces severe malfunction of a papillary muscle or rupture of a chorade tendineae. Acute infarctectomy alone is not recommended at this time. The balloon assist device may result in some patients who are candidates for infarctectomy with aortocoronary bypass graft. Preinfarction angina which is not controlled by medical therapy should be treated by immediate aortocornary bypass. Tachyarrhythmias are not an absolute contraindication to surgery. Stable angina that is unacceptable to the patient under optimal medical therapy and is associated with operable anatomical lesions is the prime indication for coronary artery surgery. Relief of pain and increased exercise tolerance are usual after surgery. Sometimes life may be prolonged.

Angina Pectoris↗
PubMed1977

Cyanoacrylate sealing of pancreatic biopsy sites in dogs.

The ability of ethyl cyanocrylate monomer adhesive in preventing leaks following pancreatic surgery dogs was evaluated. Seventeen of 18 dogs in the control group had evidence of pancreatic leak following biopsy. There was no evidence of leak in 17 of 18 dogs on which the adhesive was used to seal the cut surface of the pancreas. Similar successful use of ethyl cyanoacrylate in patients would provide a safe method of taking a specimen from a mass for biopsy in the pancreas.

Animals↗