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Biomedical subjects

L G Martin

Publications and source records attributed to L G Martin.

At least 19 recordsLinked to original sources
PubMed1995

Third degree atrioventricular block and acquired myasthenia gravis in four dogs.

Third degree atrioventricular block was diagnosed in 4 dogs with acquired myasthenia gravis (serum acetylcholine receptor antibody titer > 0.6 nmol/L). All 4 dogs had megaesophagus. Two dogs also had mediastinal thymomas, which were resected. One dog with thymoma received a permanent pacemaker at the same time that it underwent thymectomy; the other did not develop third degree atrioventricular block until 3 months after thymectomy. Both dogs with thymoma died of severe aspiration pneumonitis within 3 months after surgery. The third dog received a permanent pacemaker and was treated with pyridostigmine bromide, but also died of aspiration pneumonitis 1 month after the pacemaker was implanted. The fourth dog was treated with prednisolone and pyridostigmine bromide and improved, but did not become clinically normal. Because third degree atrioventricular block as well as myasthenia gravis can cause signs of weakness, acquired myasthenia gravis should be considered in dogs with idiopathic cardiac conduction disturbances. Likewise, an ECG should be evaluated in dogs with acquired myasthenia gravis.

Animals↗
PubMed1994

Hematologic emergencies.

The most common life-threatening hematologic emergencies include hemorrhage and severe anemia. Successful treatment of these conditions depends on the emergency veterinarian having a thorough understanding of the possible etiologies of these conditions, and a systematic approach to diagnosis and therapy. Use of blood component therapy can be a life-saving technique in these patients. The goal of this article is to familiarize the emergency veterinarian with a systematic approach to the diagnosis and treatment of hematologic emergencies.

Anemia↗
PubMed1994

Transjugular intrahepatic portal systemic shunt for the management of symptomatic cirrhotic hydrothorax.

OBJECTIVE: To investigate the safety and effectiveness of performing transjugular intrahepatic portal systemic shunt (TIPS) for the management of symptomatic cirrhotic hydrothorax in patients with advanced cirrhosis. METHODS: TIPS was performed by standard technique after portal vein patency had been established by ultrasound. Portal-hepatic vein pressure gradient was determined before and after placement of the shunt. A portal-hepatic vein gradient of less than 12 mm Hg was the treatment goal. RESULTS: Five patients underwent TIPS placement over an 11-month period. Despite use of diuretics, the patients had required a median of seven thoracenteses (range 2-11) for control of symptoms preceding placement of the shunt. A TIPS was placed without serious complications in all five patients. In two patients, insertion of the shunt was associated with no further need for thoracentesis. The other three patients had recurrent need for thoracentesis. These three patients were found to have occluded shunts which were rendered patent by angioplasty and/or urokinase. Subsequently, two required no further thoracentesis, whereas, in the other patient, the need for thoracentesis was decreased dramatically. CONCLUSIONS: TIPS appears to be a safe and useful technique for the management of patients with symptomatic cirrhotic hydrothorax that is refractory to medical therapy. Recurrence of the pleural effusion after placement of TIPS may be an indication of shunt occlusion.

Adult↗
PubMed1993

Local infusion of fibrinolytic agents for acute renal artery thromboembolism: report of ten cases.

Management of acute renal artery occlusion remains a therapeutic challenge. We report our experience with 10 cases of acute renal artery occlusion treated primarily by local infusion of fibrinolytic agents. Renal artery occlusion occurred as a result of thrombosis of a stenosed vessel in three cases, from renal artery embolism in two cases, as a complication of percutaneous transluminal angioplasty in four cases, and in association with aortic occlusion in one case. Flank pain was present in all cases and hematuria in four cases. Acute renal failure was seen at the time of presentation in four cases (one case from bilateral occlusion and three cases from an associated nonfunctioning contralateral kidney). Diagnosis was confirmed by renal isotope scanning and arteriography in all cases. All patients were treated by selective infusion of streptokinase or urokinase into the occluded renal arteries. In five cases this was combined with balloon catheter angioplasty. Therapy was initiated within 24 hours from the onset of symptoms in three cases, within 3 days in four cases, within 6 days in two cases, and after 5 weeks in one case. Successful revascularization was initially achieved in 7 of the 10 cases by arteriographic criteria. Rethrombosis occurred in one patient after 3 days and fibrinolytic therapy was repeated successfully. Renal function was restored in one of the four patients presenting with acute renal failure. One complication necessitating resection occurred as a result of fibrinolytic therapy in the form of acute mesenteric embolism with descending colon infarction. No major bleeding complications were encountered and there were no deaths in this group of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

Effects of sex steroids on myocardial anoxic resistance.

Eight treatment groups of CD strain castrate male or female rats were injected daily with cottonseed oil (sham), testosterone propionate (50 micrograms/100 g body wt), estradiol benzoate (7 micrograms/100 g body wt), or a combination of both steroids dissolved in cottonseed oil. These physiologic replacement dosages of sex steroids, determined by bioassay procedures, were injected in a 0.1-ml bolus of cottonseed oil daily (intraperitoneally) for 16 weeks. Myocardial anoxic resistance was quantified by means of an in vitro right ventricular strip preparation that evaluated the ability of the isolated right ventricle to maintain contractions in response to electrical pacing at 1 Hz after 10 min of anoxia. While this parameter was elevated 2- to 3-fold in the estrogen-treated groups of male and female castrates compared with the sham (oil)-injected groups, neither testosterone treatment alone nor combination steroid treatment produced anoxic resistance values that differed significantly from those of the sham-injected animals. Thus, although estrogen alone may afford anoxic protection to the myocardium, testosterone is able to abolish this hormone-induced protection.

Analysis of Variance↗
PubMed1993

Polytetrafluoroethylene aorta-vena cava graft for hemodialysis: report of a case.

In children with chronic renal failure, vascular access for hemodialysis is difficult because of the small size of the vessels and the requirement for substantial blood flow through the fistula or graft. As the child grows older, the ease of constructing a satisfactory access usually increases as the vessels increase in size. Unfortunately, this increased ease is often offset by the paucity of suitable access sites because the larger peripheral sites have already been used with only transient success. We report a child with chronic renal failure since 1 month of age with no peripheral sites available because of prior failed procedures who underwent placement of polytetrafluoroethylene limbs to the aorta and vena cava at the age of 6 years. He has continued on hemodialysis for the past 4 1/2 years with this technique of vascular access.

Animals↗
PubMed1992

Nonoperative management of visceral aneurysms and pseudoaneurysms.

During the period from 1975 to 1991, 41 patients with 60 visceral artery aneurysms were treated at the Affiliated Hospitals of Emory University. The total included 13 patients in whom 16 aneurysms were treated primarily by transarterial embolization. There were seven hepatic artery aneurysms, three splenic artery aneurysms, three gastroduodenal artery aneurysms, two left gastric artery aneurysms, and one right gastroepiploic artery aneurysm. Average age of these patients was 50 years; there were eight males and five females. Seven patients presented with gastrointestinal bleeding, and two patients presented with abdominal pain. In four patients, the aneurysm was an incidental finding. Etiology of the true or false aneurysms consisted of pancreatitis in two patients, trauma in three patients, connective tissue disease in one, and was unknown in the remainder. Embolization was performed in seven cases with Gianturco coils and Gelfoam, with coils alone in four, with Gelfoam alone in four, and with detachable balloons in one instance. Complete occlusion was achieved initially in 13 cases. Recanalization occurred in two patients over a mean follow-up period of 8.6 months, requiring re-embolization in one patient, whereas the other patient was managed expectantly. In three cases, embolization was unsuccessful: two cases required surgical correction, and one case was managed expectantly. Only one complication was related to the embolization procedure, which was a common hepatic arterial dissection that proceeded to the formation of a false aneurysm. Embolization as the primary treatment modality for visceral artery aneurysms should be considered in patients with the following diagnoses: pseudoaneurysms associated with pancreatitis, intrahepatic aneurysms, most splenic artery aneurysms, and gastric, gastroduodenal, and gastroepiploic aneurysms. The procedure has a low risk and may obviate a difficult surgical procedure, but it does not preclude surgical intervention should the need arise.

Adolescent↗
PubMed1992

Long-term results of angioplasty in 110 patients with renal artery stenosis.

Percutaneous transluminal renal angioplasty (PTRA) is generally considered of little benefit in the treatment of ostial renal artery stenosis. This report contains long-term follow-up (> 12 months in all patients; mean follow-up, 38 months) for 110 patients who underwent PTRA for treatment of ostial renal artery stenosis. There was no significant difference in patient benefit related to bilaterality or multiplicity of lesions treated or to renal function before angioplasty (P > .1). Although there was no statistically significant difference in benefit among groups of patients who received treatment, certain trends were apparent. The least benefit occurred in patients with insulin-dependent diabetes and those with symptoms or history of vascular disease in another organ system. Treatment of lesions with proportionately larger balloons did not result in greater benefit. Restenoses were redilated in 16 patients for whom initial treatment failed. Eleven of these were ostial restenoses. The ostial stenosis in one patient was redilated a second time. At the end of follow-up, primary, secondary, and tertiary clinical benefits were 48%, 57%, and 58%, respectively. This was not statistically different (P = .14) from a control group of 94 patients with nonostial stenoses who had 68% long-term benefit. The authors conclude that ostial renal artery stenosis is not a contraindication to PTRA, and balloon angioplasty can play an important role in blood pressure control in this patient population.

Adult↗
PubMed1992

Living arrangements of elderly Japanese and attitudes toward inheritance.

Using data from the 1988 Mainichi Newspaper/Nihon University National Family Survey, we analyzed the living arrangements and attitudes toward inheritance of Japanese aged 60 and over. Logit analysis indicates that living arrangements are influenced by gender, age, marital status, education, urban residence, and number of living children. Log-linear modeling of inheritance attitudes shows that living with married children, lower educational attainment, and living in a traditionally agricultural area are associated with favoring bequests to eldest sons, as opposed to bequests to all children equally or to whoever takes care of the elderly person. The results are consistent with modernization theory of gerontology and convergence theory of family sociology in that elderly persons with more "modern" characteristics are more likely to depart from prewar ideals of living with married children and preferring bequests to eldest sons only.

Aged↗
PubMed1992

Different roles for two enhancer domains in the organ- and age-specific pattern of polyomavirus replication in the mouse.

Viral replication in mice infected with murine polyomavirus strains with novel enhancer rearrangements was analyzed by direct in situ hybridization of whole mouse sections and by hybridization of nucleic acids extracted from a specific set of organs. The enhancer rearrangements included a deletion of the B domain as well as duplications within the A domain. Comparisons between enhancer variants demonstrate that the B domain plays an important role in replication in most organs, in particular in the kidney, at the neonatal stage (days 0 to 7 postbirth). In contrast, the B domain is not required in those organs which can sustain replication in the adult, i.e. mammary gland, skin, and bone (class I organs [J. J. Wirth, A. Amalfitano, R. Gross, M. B. A. Oldstone, and M. M. Fluck, J. Virol. 66:3278-3286, 1992]). Altogether, the results suggest that the B and A domains mediate very different functions in infection of mice, controlling the acute and persistent phases of infection, respectively. A model of mouse infection based on the crucial role of differentially expressed host transcription factors is presented.

Aging↗
PubMed1992

Arterial injuries associated with complete dislocation of the knee.

To determine the frequency and type of arterial injuries associated with complete dislocation of the knee and to correlate the findings at physical examination with those at arteriography, a computerized search for patients with a diagnosis of dislocation of the knee at discharge from an urban trauma hospital was performed. Nineteen patients with complete dislocation of the knee were found. Arterial injuries were seen in six patients (32%). Four of the 19 patients had no pedal pulse at physical examination. In three of these four patients, occlusion of the popliteal artery was seen on arteriograms. The fourth patient had occlusion of an anomalous anterior tibial artery and a compartmental syndrome. Two of the 15 other patients with pedal pulses (13%) had nonoccluding intimal defects of the popliteal artery; these two patients did well without surgery. It is concluded that abnormal peripheral pulses associated with complete knee dislocation are highly predictive of major arterial injury. If peripheral pulses are normal, a low but definite frequency of arterial damage exists.

Adult↗
PubMed1992

Peripheral transcatheter embolization with platinum microcoils.

Embolotherapy with platinum microcoils delivered through the Tracker-18 microcatheter (Target Therapeutics, San Jose, Calif) was performed in 16 patients when peripheral superselective catheterization with standard angiographic catheters was not possible. The Tracker-18 catheter could be directed distally into small peripheral vessels for delivery of the microcoils. These microcoils, with attached fiber strands, resulted in vascular occlusion within a few minutes in all cases. Embolotherapy was technically successful in all patients. The procedures were clinically successful in 15 of 16 patients (94%), and no complications were encountered. Embolization with platinum microcoils through the Tracker-18 catheter is useful when standard methods of embolization are not possible.

Adolescent↗
PubMed1991

Population aging policies in East Asia and the United States.

As a result of successful efforts to reduce fertility and mortality, East Asian populations are beginning to age, in some cases rapidly. Policies in response to population aging range from attempts in Singapore to reverse it by encouraging more births to efforts in Japan to accommodate it by increasing employment opportunities for older workers. The population of the United States, which had a longer postwar baby boom, is aging more slowly than these two countries and may be able to learn from the East Asian experience with aging policies.

Aging↗
PubMed1991

Therapy of the Kasabach-Merritt syndrome with cryoprecipitate plus intra-arterial thrombin and aminocaproic acid.

A patient with the Kasabach-Merritt syndrome with disseminated intravascular coagulopathy and congestive heart failure due to a giant hepatic cavernous hemangioma achieved thrombosis of his tumor with a combination of cryoprecipitate plus intra-arterial thrombin and epsilon aminocaproic acid. This was documented by an absence of Indium 111-labelled platelet sequestration, marked decrease in thrombin:antithrombin complex generation, and normalization of platelet count and fibrinogen. Interventional angiography with aminocaproic acid and thrombin is advocated in patients whose tumors are amenable to such an approach so as to avoid a systemic antifibrinolytic state.

Aged↗
PubMed1991

Young Investigator Award. Raman spectroscopy of human atherosclerotic plaque: implications for laser angioplasty.

Raman spectroscopy is a specialized technique that permits highly specific identification of specimens, in contrast to fluorescence spectroscopy with which analysis of arterial tissues generates spectra that are broad and featureless, with little difference seen between normal artery and atheroma. Various plaque types and the contributions of different arterial fluorophores were studied to determine if Raman spectroscopy could function as a potential guidance modality for laser angioplasty. Arterial specimens obtained at atherectomy and post mortem were studied in air and while immersed in blood. One hundred fifty-six Raman spectra were collected from arterial specimens and chromatographic samples of collagen, elastin, cholesterol, beta-carotene, and L-tryptophan. Analysis showed both fatty and fibrous atherosclerotic plaques to have characteristic spectral peaks at 1,002, 1,154, and 1,516 cm-1, while the Raman spectrum of normal vessel was featureless. Spectral peaks of beta-carotene were nearly identical to those of fatty plaque. The arterial fluorophores collagen, elastin, cholesterol, and L-tryptophan were non-contributory. The Raman spectrum of fatty plaque immersed in a blood field was also detectable, suggesting that this technique may be useful for in vivo plaque recognition.

Angioplasty, Laser↗
PubMed1991

The utility of 99mTc-mercaptoacetyltriglycine in captopril renography.

99mTc-Mercaptoacetyltriglycine (MAG3) is a new 99mTc renal radiopharmaceutical with properties similar to orthoiodohippurate (OIH). 99mTc-MAG3 is highly protein bound and is efficiently extracted by the proximal tubules. While the clearance is only 50 to 65% that of OIH, the plasma concentration is higher and the rates at which the two tracers appear in the urine are almost identical. Studies comparing 99mTc-MAG3 and OIH in animals with renovascular hypertension (RVH) show comparable results. Preliminary studies comparing 99mTc-MAG3 renography with angiography in hypertensive patients show promising results and suggest 99mTc-MAG3 will probably have a sensitivity and specificity for detecting RVH similar to OIH. The optimal criteria for defining an abnormal study still need to be determined and then applied in a prospective study.

Animals↗
PubMed1991

Benign biliary strictures: treatment with percutaneous cholangioplasty.

Results of percutaneous balloon cholangioplasty of 17 patients with 28 benign biliary strictures were compared with those of published radiologic and surgical series to determine whether stricture location was related to therapeutic success and whether a patient should undergo percutaneous or surgical therapy. Treatment was considered successful if there was no anatomic evidence of recurrent stricture or need for surgery (mean follow-up, 32 months). Treatment was successful in all nine (100%) intrahepatic (zone 1) strictures, 11 of 12 (92%) extrahepatic-extrapancreatic (zone 2) strictures, one of three (33%) intrapancreatic (zone 3) strictures, and three of four (75%) bilienteric anastomotic (zone 4) strictures. Restenosis occurred in five patients; cholangioplasty was ultimately successful in two of those patients after redilation and stent placement. On the basis of these results and those of published radiologic and surgical series, the authors believe that cholangioplasty is the treatment of choice for zone 1 strictures and is as effective as surgery for zone 2 and 4 strictures. Patients with zone 2 and 4 strictures with concomitant portal hypertension or a history of multiple previous biliary surgical procedures should be considered good candidates for cholangioplasty. Zone 3 strictures may be better treated surgically than percutaneously.

Aged↗