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Biomedical subjects

P Martin

Publications and source records attributed to P Martin.

At least 379 records · Page 21Linked to original sources
PubMed1997

Presurgical localization of abnormal parathyroid glands using a single injection of technetium-99m methoxyisobutylisonitrile: comparison of different techniques including factor analysis of dynamic structures.

Single-tracer methoxyisobutylisonitrile (MIBI) imaging is considered to be a sensitive method for the localization of abnormal parathyroid glands. The aims of this study were to determine which of the analytical techniques described for this method - visual comparison of early (15-min) and late (120-min) images, use of time-activity curves (TACs) generated on regions of interest and factor analysis of dynamic structures (FADS) - corresponds best with surgical findings, and to ascertain the potential overall contribution of presurgical scintigraphy. Fifty-five patients were studied, 34 of whom presented with primary hyperparathyroidism (HPT) and 21 with secondary HPT. After a 925 MBq injection of technetium-99m MIBI, a 40-min dynamic acquisition was performed and static images were acquired at 5, 20, 40 and 120 min using a gamma camera equipped with a pinhole collimator. The dynamic series were submitted to FADS, an attractive non-operator-dependent technique, and TACs were generated on regions of interest after the visual comparison of early and 120-minute images (15'-120'). The presumed localizations of abnormal glands were compared with a sketch drawn by the surgeon. Sensitivity was defined as the percentage of true-positive localizations and was 84.4%, 74% and 65% in adenoma and 76%, 66.6% and 45% in hyperplasia for 15'-120', FADS and TACs, respectively. Surgical accuracy, i.e. the percentage of patients accurately and completely described, was 72%, 56% and 59% in adenoma and 53%, 30% and 22% in hyperplasia for 15'-120', FADS and TACs, respectively. The visual comparison method scored best in all cases. FADS was found to be sensitive in cases of adenoma but was handicapped by more false-positive localizations. TACs were particular inefficient in hyperplasia. With respect to the detection of adenomas, we found a relationship between the gland weight and scintigraphic positivity. This dependence on gland weight was not found in hyperplasia. The poorer results obtained with all techniques for surgical accuracy can be explained by the need for a complete scintigraphic description of all pathological glands found by the surgeon in a patient. This study demonstrates that the 15'-120' visual comparison method is more efficient and less cumbersome than TAC or the attractive FADS technique. However, it was less efficient than neck exploration by an experienced surgeon. Therefore, in our institution, scintigraphic studies are now only requested in selected cases of HPT, usually primary HPT and cases undergoing re-operation.

Adenoma↗
PubMed1997

Antidepressant treatment in helpless rats: effect on the electrophysiological activity of raphe dorsalis serotonergic neurons.

Chronic treatment with antidepressants renders serotonergic neuronal firing less sensitive to the inhibitory effect of serotonin (5-HT) reuptake blockers in the rat, and this has been considered as a major correlate of the therapeutic action of these drugs. We investigated whether the same mechanisms could be evidenced in an experimental model of depression, the learned helplessness paradigm. Rats rendered helpless by a single session of inescapable electrical footshocks exhibit, for several days, depression-like behavioural deficits which can be reversed by sub-chronic, but not acute, treatment with antidepressants. Recording of serotonergic neurons in the dorsal raphe nucleus revealed that, under baseline conditions, the spontaneous firing was similar in helpless rats and in non-helpless controls. However, neurons in the former group exhibited an enhanced sensitivity to the inhibitory action of the 5-HT reuptake blocker, citalopram (ED50 = 0.18 +/- 0.02 mg/kg IV in helpless rats versus 0.27 +/- 0.03 mg/kg IV in controls, P < 0.05). Treatment with zimeldine during 3 consecutive days induced in both helpless and control rats, a decrease in the inhibitory response of serotonergic neurons to the citalopram challenge, which resulted in a normalization of the neuronal reactivity in the helpless group (ED50 = 0.31 +/- 0.03 mg/kg IV). Since this adaptive phenomenon parallels the behavioural improvement induced by the repeated administration of zimeldine and other antidepressants in helpless rats, it might be considered as a crucial event in the mechanism of therapeutic action of these drugs.

Action Potentials↗
PubMed1997

Wound healing in embryos: a review.

Skin wounds in young embryos heal rapidly, efficiently and perfectly without scar formation, an ability that is lost as developmental proceeds. The tissue movements of repair (re-epithelialisation and connective tissue contraction) are the same in embryos as adults, but the means by which these movements are achieved are very different. Whilst adult wound front epidermal cells crawl forwards over the exposed substratum to close a defect, a gap in the embryonic epidermis is closed by contraction of a rapidly assembled actin purse-string. In the adult wound situation connective tissue contraction is brought about by specialist contractile myofibroblasts, but in the embryo standard embryonic fibroblast exert similar tractional forces to bring the wound margins together. We review what is known of the cellular sources and the levels of various growth factor signals that might activate wound closure movements during embryonic and adult repair and how this knowledge might help in designing therapeutic strategies to enhance adult healing. Finally we discuss how studies of the tissue movements of embryonic wound healing may guide our understanding of more natural tissue movements that occur during embryogenesis, such as gastrulation and neurulation.

Actins↗
PubMed1997

Cardiovascular effects of recombinant human erythropoietin in predialysis patients.

Treatment with recombinant human erythropoietin (rHuEPO) has solved the problem of anemia in patients on dialysis. However, its application to predialysis patients has raised some doubts about its effects on the progression of renal disease and on blood pressure (BP) and hemodynamic regulation. We have prospectively studied over at least 6 months a group of 11 predialysis patients receiving rHuEPO treatment (initial dose, 1,000 U subcutaneously three times a week). Clinical assessment and biochemical and hematologic measurements were made once every 2 weeks. Twenty-four-hour ambulatory BP monitoring, echocardiography, and determination of neurohumoral mediators of hemodynamics were performed once every 3 months. An adequate hematologic response was found (hemoglobin, 11.7 +/- 0.4 g/dL v 9 +/- 0.3 g/dL) without changes in the progression of renal disease. A decrease in cardiac output and an increase in total peripheral resistance was seen as anemia improved. A trend toward decreased left ventricular (LV) thickness and a significant decrease in LV mass index (from 178.2 +/- 20.6 g/m2 to 147.3 +/- 20.6 g/m2) were observed. Blood pressure control did not improve; moreover, in some patients an increase in systolic values was detected by ambulatory BP. Casual BP remained seemingly stable. Sequential determinations of neurohumoral mediators of hemodynamic substances (endothelin, renin, norepinephrine, epinephrine, dopamine) failed to explain these results. Ambulatory BP reveals a worse control in some patients who were previously hypertensive and confirms the utility of this technique in the assessment of patients under erythropoietin treatment. The trend toward LV hypertrophy regression without improved BP control confirms the role of anemia among the multiple factors leading to LV hypertrophy in end-stage renal disease (ESRD), and opens therapeutic possibilities. Better control of BP may avoid a potential offsetting of beneficial effects that correcting anemia would have on the cardiovascular system.

Adult↗
PubMed1997

Rapid analysis of 226Ra in waters by gamma-ray spectrometry.

Techniques for the determination of 226Ra in waters by gamma-ray spectrometry are examined, with an emphasis on methods capable of completion within 1-3 days of sample collection. Methods discussed utilise either: (i) the 186 keV 226Ra gamma ray, with the contribution from 235U being subtracted after a separate uranium determination, or (ii) measurement of ingrowing 222Rn progeny. An analysis of the statistical and systematic errors associated with each technique is presented. Examples are given of their application to analysis of uranium mine process waters.

Chemical Precipitation↗
PubMed1997

Effects of cardiopulmonary bypass on neonatal and paediatric inflammatory profiles.

OBJECTIVE: Cardiopulmonary bypass (CPB) causes significant morbidity in paediatric patients, yet the mechanisms involved in the related inflammatory processes (resulting in capillary leak and edema) are poorly understood. Moreover, earlier palliative and corrective intervention in neonates and infants has provided the cohorts of patients about whom little is known of their proinflammatory response. METHODS: In the present two group study, 14 neonates (age 1-28 days, 2.5-4.5 kg) and 13 infants (2-12 months, 3-7 kg), undergoing CPB for congenital heart disease were consecutively recruited. The two cohorts were well matched in terms of CPB and aortic cross-clamp times (P > 0.1). Blood samples were collected on induction of anaesthesia, 5 min following onset of CPB, at the end of CPB, and 30 min, 2 and 24 h post-protamine (PP) administration. Plasma concentration of cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8), terminal complement complex (C5b-9) neutrophil counts and leucocyte elastase were measured. RESULTS: Plasma levels of all inflammatory markers significantly increased in both groups during and following CPB as compared to baseline. During and following CPB the change in IL-8 level was more pronounced in neonates (peak 30 min PP, median(range): 1062 (182-3872) pg/ml) than in infants 568 (172-1368) pg/ml), P = 0.01. Changes in IL-6 level were indistinguishable between groups intraoperatively, but remained significantly higher at 24 h in neonates (P = 0.02). Peri and postoperative levels of C5b-9 were significantly higher in infants than in neonates (peak 30 min PP, median (range): 984 (118-1142) ng/ml vs 458 (22 1340) ng/ml in neonates respectively, P = 0.01) but were similar at 24 h. Despite this, leucocyte elastase profiles did not differ significantly between the respective cohorts. CONCLUSION: These results indicate that there may be differences between neonates and infants with regard to the inflammatory response to CPB and neonatal patients merit further investigation in order to elucidate whether the pathophysiology of their CPB related inflammatory response and its clinical sequelae differs from their older counterparts.

Cardiopulmonary Bypass↗
PubMed1997

Cell activation and thrombin generation in heparin bonded cardiopulmonary bypass circuits using a novel in vitro model.

OBJECTIVE: It is generally agreed that when the blood contact surfaces of a cardiopulmonary bypass circuit are treated with a layer of heparin molecules the activation of the humoral pathways is attenuated. However, there is still debate as to whether heparin-bonded circuits reduce thrombin generation. This study aims to examine the effects of immobilized heparin on cell activation and thrombin generation in a novel, well controlled model of cardiopulmonary bypass. METHODS: The model used consisted of a heparin-bonded and a non-bonded cardiopulmonary bypass circuit perfused in tandem with the same unit of fresh heparinized (3.3 U/ml) human blood for a period of 6 h. Samples were taken for analysis from the bag just prior to perfusion and at 30, 60, 120 and 360 min of perfusion. Whole blood was used to analyse platelet and white blood cell count, haematocrit and activated coagulation time. Plasma samples were prepared for batch analysis of the cell activation markers p-selectin, elastase and interleukin-8, and the thrombin generation markers thrombin-antithrombin and prothrombin fragment F1 + 2. A sample of tubing was taken from each circuit at the end of the perfusion and prepared for visualization by scanning electron microscopy. RESULTS: Platelet counts were significantly reduced in the non-bonded circuits compared with the heparin-bonded circuits at 30 (22 versus 200 x 10(9)/L P < 0.01), 60 (26 versus 193 x 10(9)/L P < 0.01) and 120 min (28 versus 193 x 10(9)/L P < 0.01) as were white blood cell counts at 30(1.5 versus 2.7 x 10(9)/L P < 0.01), 60 (0.9 versus 2.4 x 10(9)/L P < 0.01), 120 (0.9 versus 1.8 x 10(9)/L P < 0.01) and 360 min (0.4 versus 0.9 x 10(9)/L P < 0.05). The concentration of p-selectin was found to be significantly higher in the non-bonded circuits than in the heparin-bonded circuits at 30 (37 versus 29 ng/ml P < 0.01), 60 (37 versus 28 ng/ml P < 0.01). 120 (42 versus 27 ng/ml P < 0.01) and at 360 min (72 versus 46 ng/ml P < 0.01). Elastase was elevated in the non-bonded circuits at 30 (570 versus 145 micrograms/l P < 0.01), 60 (646 versus 278 micrograms/l P < 0.01) and 120 min (613 versus 403 micrograms/l P < 0.05) and interleukin-8 at 120 (705 versus 520 pg/ml P < 0.05) and 360 min (11326 versus 9910 pg/ml P < 0.05). A similar picture was found for the thrombin generation markers. Thrombin-antithrombin complexes were raised in the non-bonded circuits compared with heparin-bonded circuits at 60 (24 versus 13 micrograms/l P < 0.05) and 120 min (46 versus 17 micrograms/l P < 0.05) as was prothrombin fragment F1 + 2 at 30 (1.1 versus 0.7 nmol/l P < 0.01), 60 (1.3 versus 0.7 nmol/l P < 0.01), 120 (1.8 versus 0.9 nmol/l P < 0.01) and 360 min (15.0 versus 13.6 nmol/l P < 0.05). Scanning electron microscopy revealed a greater amount of adherent material on the non-bonded surface relative to the heparin-bonded surface. CONCLUSIONS: In a cardiopulmonary bypass circuit perfused with human blood the activation of platelets and white blood cells has been seen to be significantly reduced in the presence of a heparin-bonded surface. Thrombin generation due to contact activation of the intrinsic coagulation pathway is also reduced.

Adult↗
PubMed1997

Proinflammatory cytokine release during pediatric cardiopulmonary bypass: influence of centrifugal and roller pumps.

OBJECTIVE: It has been proposed that nonocclusive centrifugal pumps may elicit less blood cell trauma and hence a reduced inflammatory response than standard roller pumps. However, there have been no reports describing the impact of such pumps on proinflammatory cytokine release in pediatric cohorts. DESIGN: A prospective randomized study was undertaken. SETTING: A regional cardiothoracic center of a university hospital. PARTICIPANTS: Thirty-four pediatric patients undergoing cardiopulmonary bypass (CPB) for the correction of complex congenital heart defects were recruited. INTERVENTIONS: Either standard twin roller (n = 17), or centrifugal vortex (Biopump, Medtronic Biomedicus Inc, MN) (n = 17) blood pumping. MEASUREMENTS AND MAIN RESULTS: Venous blood was drawn (1) on induction of anesthesia, (2) 5 minutes on bypass, (3) end of CPB, (4) 30 minutes post-protamine, (5) 2 hours and (6) 24 hours postoperation. Neutrophil count, level of plasma leukocyte elastase, terminal complement complex (C5b-9); interleukin-6 (IL-6) and interleukin-8 (IL-8) were increased during and after CPB compared with the postinduction baseline. C5b-9 levels in both groups peaked at the end of CPB before returning to baseline at 24 hours: (median [range]), 564 (16 to 1,136) ng/mL in centrifugal group versus 508 (0 to 1,128) ng/mL in the roller group. IL-6 in both groups reached its peak level at 2 hours postprotamine (208 [98 to 411] pg/mL in centrifugal versus 205 [60-327] pg/mL in the roller group), before coming back to baseline at 24 hours. Plasma leukocyte elastase and IL-8 reached their maximum level 15 minutes after protamine administration: 215 (64 to 375) pg/mL in centrifugal versus 235 (87 to 410) pg/mL in roller group; and 700 (90 to 5,925) ng/mL versus 362 (120 to 3,400) ng/mL, respectively. CONCLUSIONS: The current study confirms the proinflammatory nature of pediatric CPB surgery, but failed to show a significant advantage of centrifugal pumping over roller perfusion in terms of the inflammatory response.

Cardiopulmonary Bypass↗
PubMed1997

Variants of melanoma.

The current classification of malignant melanomas gives recognition to superficial spreading melanoma, lentigo maligna melanoma, acral lentiginous melanoma, and nodular types. In addition, neurotropic and desmoplastic types are recognized. The relativity inherent in the diagnosis of melanoma, provides the basis for the classification of melanomas on the basis of size. Lesions measuring 1 mm or less in vertical dimensions are unlikely to metastasize; they qualify as borderline melanocytic neoplasia of indeterminant malignant potential. The current classification has little relevancy to the category of variant nevi with the exceptions of malignant cellular blue nevus and melanoma arising in giant congenital nevi. A classification of variant melanomas as related to variant nevi is proposed. From a different perspective, a classification of melanomas with attention to nesting and cytological patterns in vertical growth is proposed: this alternate approach gives recognition to lesions that might otherwise be classified as "nevoid" melanomas. It also provides a default category for lesions that might otherwise be assigned to the Spitz nevus-like category. All of these tools for the manipulation of the real and virtual images of melanomas have been emphasized in the concept of minimal deviation melanoma.

Diagnosis, Differential↗
PubMed1997

[Radiotherapy of macular lesions in age-related macular degeneration (AMD): initial results of a study inducted in Lyon, France].

PURPOSE: To evaluate irradiation effects on functional signs and choroidal neovascular lesions in age-related macular degeneration (AMD) that does not respond to laser therapy. MATERIALS AND METHODS: Since 1994, 250 consecutive AMD patients were treated by two radiotherapy teams for subfoveal neovascular lesions. At the end of September 1996, 52 patients were evaluable with a 1-year follow-up. Group 1 (Département de Radiothérapie Oncologie, Centre Hospitalo-Universitaire Lyon Sud) included 26 patients who were treated with a lateral beam of 6 MV photons. The irradiation doses were 20 Gy in five fractions for small lesions and 28.8 Gy in eight fractions for larger lesions. Group 2 (Centre Oncologie Radiothérapie Saint-Jean) was composed of 26 patients treated with a mini-beam of 25 MV photons via lateral arc-therapy. Beam diameters (14 and 18 mm) were adapted to the lesion size. The total dose was 16 Gy in four fractions or 20 Gy in five fractions. RESULTS: Functional and anatomical results were assessed at 3, 6, 9 months and 1 year after radiation therapy. Stable visual acuity was observed in 44% (23/52) of the patients and visual acuity was improved in 35% (18/52) of the patients at 6 months. Good functional results reached 79% (41/52) at 6 months and 74% (17/23) at 12 months. A significant decrease (> 10%) of the membrane was present in 46% (16/52) of the cases at 6 months and in 65% (15/23) of the cases at 12 months. There was no statistical difference between the two groups and dose levels. All severe complications (1 cataract, 3 dilated choridal vessels, and 2 papillitis) occurred in group 1. CONCLUSION: Though it is too early to conclude on the best dose level, radiotherapy of subfoveal neovascular lesions of AMD that cannot be treated via laser therapy provides encouraging results. The technique used must be very precise to adequately irradiate the fovea and spare surrounding sensitive areas. Further studies and trials involving patients' randomization are necessary to confirm these preliminary results.

Aged↗
PubMed1997

Predictors of loneliness in centenarians: a parallel study.

The purpose of this study was to evaluate predictors of loneliness in centenarians for two countries: The USA and Sweden. It was hypothesized that cognition, personality, social support and physical health would predict loneliness. Results indicated that personality, social support and physical health were good predictors of loneliness in the US sample, while cognition and social support were the strongest predictors in the Swedish sample. Social support predicted loneliness negatively in the US sample, but was positively associated with loneliness in Sweden.

Journal Article↗
PubMed1997

Common defects of different retinoic acid resistant promyelocytic leukemia cells are persistent telomerase activity and nuclear body disorganization.

The acute promyelocytic leukemia (APL) t(15;17) rearrangement fuses the promyelocytic leukemia (PML) gene to the retinoic acid receptor-alpha (RAR alpha). There is expression of the chimeric transcript, PML/RAR alpha, in these APL cells. These clinical APL cases respond to the differentiation agent all-trans retinoic acid (ATRA) with complete but not durable remissions because ATRA resistance develops. The NB4 APL cell line expresses PML/RAR alpha and responds to the growth inhibitory and differentiation-inducing signals of ATRA. To identify mechanisms responsible for ATRA resistance in APL, ATRA-resistant NB4 cell lines were derived from parental NB4 cells using different strategies. These lines were resistant to the growth inhibition and differentiation effects of ATRA. ATRA-resistant cells were isolated as a de novo resistant line from parental NB4 cells (NB4-R1), following chemical mutagenization and selection in ATRA (NB4-R2), or after chronic selection in ATRA (NB4-R3). Common defects linked to this ATRA resistance were found. When cultured in ATRA, these resistant cells still express PML, RAR alpha, and PML/RAR alpha proteins. Sequence abnormalities were not detected in the RAR alpha DNA binding domains cloned from a representative RA-resistant NB4 line. In ATRA-sensitive but not ATRA-resistant NB4 cells, ATRA down-regulated retinoid X receptor-alpha (RXR alpha) expression, a known marker of ATRA response in parental NB4 cells. Notably, engineered overexpression of RXR alpha in ATRA-sensitive NB4 cells did not block ATRA-mediated growth suppression. ATRA treatment of these resistant NB4 lines did not signal a decline in telomerase activity or reorganization of PML-associated nuclear bodies, but both events occurred in ATRA-sensitive NB4 cells. These ATRA-resistant NB4 lines are not fully differentiation-defective, since monocytic maturation was induced following treatment with phorbol 12-myristate 13-acetate (PMA) and 1,25 dihydroxy vitamin D3 (vitamin D3). Notably, induced monocytic differentiation of these distinct ATRA-resistant APL lines markedly repressed telomerase activity. Thus, this study suggests that persistent telomerase activity and nuclear body disorganization are linked to ATRA resistance in APL.

Antineoplastic Agents↗
PubMed1997

Coccidioidomycosis in liver transplant patients.

Eight (0.59%) of 1,347 patients who underwent liver transplantation at the UCLA Medical Center (Los Angeles) developed coccidioidomycosis. Whereas only one case occurred during the first 8 years and 10 months of the UCLA Liver Transplant Program (February 1984 to December 1992), seven cases occurred within the following 23-month period (December 1992 to November 1994). The median time of onset for infection after transplantation was 8 weeks (range, 4-312 weeks). Clinical presentations of patients with coccidioidomycosis included pneumonia (six cases), pneumonia with meningitis (one case), hepatitis (one case), and monoarticular arthritis (one case). Despite therapy with amphotericin B alone (six cases) or amphotericin B plus fluconazole (two cases), infection was fatal in four of eight cases. As of this writing, the four surviving patients are receiving chronic maintenance therapy with either fluconazole (three patients) or itraconazole (one patient). These experiences show that coccidioidomycosis can be a serious and frequently fatal infection after liver transplantation and that the incidence of this disease appears to be increasing.

Adult↗
PubMed1997

Orthotopic liver transplantation for primary sclerosing cholangitis. A 12-year single center experience.

OBJECTIVE: The purpose of this study was to analyze a single center's 12-year experience with 127 orthotopic liver transplantations (OLT) for primary sclerosing cholangitis (PSC). SUMMARY BACKGROUND DATA: Primary sclerosing cholangitis is a chronic cholestatic liver disease of unknown origin that occurs most commonly in young men and is associated frequently (70-80%) with inflammatory bowel disease (IBD). Patients with PSC also are at risk for the development of cholangiocarcinoma (CCA) and those with IBD for colon carcinoma. Although the course of PSC is variable, it frequently is progressive, leading to cirrhosis and requirement for OLT. METHODS: The medical records of 127 consecutive patients undergoing OLT for PSC from July 1, 1984, to May 30, 1996, were reviewed. Actuarial patient and graft survival was determined at 1,2, and 5 years. The incidence and outcome of patients with CCA, recurrent sclerosing cholangitis, and post-transplant colon carcinoma was determined. Results were analyzed by way of stepwise Cox regression to determine the statistical strength of independent associations between pretransplant covariates and patient survival. The median follow-up period was 3.01 years. Incidental cholangiocarcinoma (ICCA) was defined as a tumor < 1 cm in size that was discovered at the time of pathologic sectioning of the explanted liver. RESULTS: Ninety-two patients (72%) had associated IBD. Seventy-nine (62%) had undergone previous biliary tract surgery. One hundred seven patients (84%) received a single graft, whereas 20 patients (16%) required 22 retransplants. Patients received either cyclosporine- (n = 76) or tacrolimus- (n = 51) based immunosuppression. The 1-, 2-, and 5-year actuarial patient survivals were 90%, 86%, and 85%, respectively, whereas graft survival was 82%, 77%, and 72%, respectively. The presence of previous biliary surgery had no effect on patient survival. Ten patients (8%) had ICCA and their survival was not significantly different from patients without ICCA (100%, 83%, and 83% at 1, 2, and 5 years, respectively). Four patients were known to have CCA at the time of OLT, all recurred within 6 months, and had a significantly worse outcome (p < 0.0001). Recurrent sclerosing cholangitis developed in 11 patients (8.6%). The patient and graft survival in this group was not different from those in whom recurrence did not develop (patient; 100%, 90%, and 90%; graft: 80%, 70%, and 52%). Thirty patients (23%) underwent colectomy after liver transplantation for dysplasia-carcinoma or symptomatic colitis. Of the nine covariates entered into the Cox multivariate regression analysis, only common bile duct frozen section biopsy specimen showing CCA was predictive of a survival disadvantage. CONCLUSIONS: Liver transplantation provides excellent patient and graft survival rates for patients affected with PSC independent of pretransplant biliary tract surgery. Incidental cholangiocarcinoma does not affect patient survival significantly. However, known CCA or common duct frozen section biopsy specimen or both showing CCA are associated with poor recipient survival, and OLT should be proscribed in these cases. Recurrent PSC occurs in approximately 9% of cases but does not affect patient survival. Post-transplant colectomy does not affect patient survival adversely.

Actuarial Analysis↗
PubMed1997

Long-term survival after retransplantation of the liver.

OBJECTIVE: The authors determined the long-term outcome of patients undergoing hepatic retransplantation at their institution. Donor, operative, and recipient factors impacting on outcome as well as parameters of patient resource utilization were examined. SUMMARY BACKGROUND DATA: Hepatic retransplantation provides the only available option for liver transplant recipients in whom an existing graft has failed. However, such patients are known to exhibit patient and graft survival after retransplantation that is inferior to that expected using the same organs in naiive recipients. The critical shortage of donor organs and resultant prolonged patient waiting periods before transplantation prompted the authors to evaluate the results of a liberal policy of retransplantation and to examine the factors contributing to the inferior outcome observed in retransplanted patients. METHODS: A total of 2053 liver transplants were performed at the UCLA Medical Center during a 13-year period from February 1, 1984, to October 1, 1996. A total of 356 retransplants were performed in 299 patients (retransplant rate = 17%). Multivariate regression analysis was performed to identify variables associated with survival. Additionally, a case-control comparison was performed between the last 150 retransplanted patients and 150 primarily transplanted patients who were matched for age and United Network of Organ Sharing (UNOS) status. Differences between these groups in donor, operative, and recipient variables were studied for their correlation with patient survival. Days of hospital and intensive care unit stay, and hospital charges incurred during the transplant admissions were compared for retransplanted patients and control patients. RESULTS: Survival of retransplanted patients at 1, 5, and 10 years was 62%, 47%, and 45%, respectively. This survival is significantly less than that seen in patients undergoing primary hepatic transplantation at the authors' center during the same period (83%, 74%, and 68%). A number of variables proved to have a significant impact on outcome including recipient age group, interval to retransplantation, total number of grafts, and recipient UNOS status. Recipient primary diagnosis, cause for retransplantation, and whether the patient was retransplanted before or after June 1, 1992, did not reach statistical significance as factors influencing survival. In the case-control comparison, the authors found that of the more than 25 variables studied, only preoperative ventilator status showed both a significant difference between control patients and retransplanted patients and also was a factor predictive of survival in retransplanted patients. Retransplant patients had significantly longer hospital and intensive care unit stays and accumulated total hospitalization charges more than 170% of those by control patients. CONCLUSIONS: Hepatic retransplantation, although life-saving in almost 50% of patients with a failing liver allograft, is costly and uses scarce donor organs inefficiently. The data presented define patient characteristics and preoperative variables that impact patient outcome and should assist in the rational application of retransplantation.

Adolescent↗
PubMed1997

Nasopharyngeal cryptococcosis.

Naturally occurring cryptococcosis in five cats, a dog and a koala is described. Involvement of the nasopharynx was documented in all patients, and nasopharyngeal mass lesions accounted for the major presenting complaints in four. Signs referable to nasopharyngeal disease included snoring, stertor, inspiratory dyspnoea and aerophagia. Diagnoses were made by caudal rhinoscopy using a retroverted flexible endoscope, vigorous orthograde flushing with saline, or at necropsy. Concurrent cryptococcal rhinitis was present in all cases, although involvement appeared limited to the caudal nasal cavity in most cases. Typical signs of nasal cavity disease, such as sneezing and nasal discharge, were often absent. Treatment of nasopharyngeal cryptococcosis should include physical dislodgement or debulking of lesion(s) to provide immediate alleviation of upper airway obstruction, followed by systemic antifungal therapy to eliminate residual infection from the nasal cavity. Infections caused by Cryptococcus neoformans var gattii accounted for a disproportionately large number of these cases.

Animals↗