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Biomedical subjects

E R Morgan

Publications and source records attributed to E R Morgan.

At least 19 recordsLinked to original sources

Agricultural restructuring and gastrointestinal parasitism in domestic ruminants on the rangelands of Kazakhstan.

In order to evaluate the epidemiology of parasitism in farmed ruminants in the changed agricultural context in Kazakhstan, 505 cattle, sheep and goats were surveyed for gastrointestinal parasitism using coprological examination, and a further thirty sheep and four goats using post mortem extraction of helminths. The dominant helminth genera were Marshallagia, Nematodirus and Trichostrongylus. Haemonchus was also present. Faecal egg counts were low (mean abundance 0-115 eggs per gram in different groups), and there was no relationship between faecal egg density and body condition score. Eggs of Nematodirus spp. were more common in sheep less than 1 yr of age, whereas those of the Trichostrongylidae were generally more common in adult sheep. Based on faecal egg counts, sheep grazing on common land close to permanent human settlements were generally no more heavily infected than those grazing the remote open plains. This could be due to a non-linear relationship between livestock numbers and stocking density. We suggest that cessation of strategic nematode control in the region following post-Soviet agricultural reform was offset by a general reduction in stocking density, such that parasite burdens remained low. However, recovery in livestock numbers is likely to lead to increased levels of infection and production loss unless sustainable control strategies are put in place.

Age Factors↗

Effects of aggregation and sample size on composite faecal egg counts in sheep.

Composite faecal egg counts (FEC) are increasingly used to support strategic anthelmintic treatment decisions in grazing livestock. However, their accuracy as estimators of group mean FEC is affected by the number of individual samples included, how thoroughly they are mixed, and the underlying degree of parasite aggregation between individual hosts. This paper uses a Negative Binomial model for parasite aggregation, and a Poisson model for egg distribution within faecal suspensions, in order to optimise composite FEC protocol for commercial sheep flocks. Our results suggest that faecal egg density in a well-mixed composite sample from 10 sheep (3g of faeces from each), estimated by examination of four independently filled McMaster chambers, is likely to provide an adequate estimate of group mean FEC in the majority of situations. However, extra care is needed in groups of sheep for which high levels of FEC aggregation might be expected. The implications of statistical error in FEC estimates depend on how they are used. The simulation-based approach presented here is a powerful tool for investigating the risks of error in FEC-driven treatment decisions in different situations, as well as for the statistical analysis of parasitological data in general.

Animals↗

Prevalence and diagnosis of parasites of the stomach and small intestine in horses in south-west England.

Parasites were extracted from the stomach and small intestine of 118 horses at slaughter. The most abundant species was the tapeworm Anoplocephala perfoliata. Maximum likelihood analysis was used to investigate the relationship between the number of worms and their total weight, and the ability of an antibody-based elisa to diagnose the level of infection. The total weight of tapeworms increased towards a maximum as the number of worms increased, suggesting a population density-dependent constraint on the weight. The number of A perfoliata present could be predicted approximately from the results of the elisa. Although wide variation in elisa optical densities confound interpretation in individual animals, tests on groups of animals could provide a useful reflection of overall levels of infection.

Abattoirs↗

Natural killer cell lymphoma: report of two pediatric cases, therapeutic options, and review of the literature.

BACKGROUND: Natural killer (NK) cell lymphomas are rapidly fatal malignancies that to the authors' knowledge are rare in children. In the current study, the authors report the cases of two boys with NK cell lymphomas with refractory disease who both were salvaged with high dose chemotherapy and stem cell transplantation and compare these patients with those in the published experience. METHODS: A comprehensive literature review was performed to identify other cases of pediatric patients with NK cell lymphomas, their treatment, and outcome. RESULTS: One of the patients in the current study developed two recurrences and the other patient experienced early disease progression during front-line treatment. Both then were treated with high dose chemotherapy followed by stem cell rescue. At last follow-up, the patients remained free of disease at 15 months and 16 months, respectively, after transplantation (48 months and 22 months, respectively, from the time of diagnosis). In addition to the 2 patients in the current study, the authors found 13 pediatric patients reported in the literature to date. Of the 7 patients with localized (Stage I-II) disease, 5 patients (71%) were reported to be alive 1-107 months after diagnosis. Of the 6 patients with Stage IV disease, only the 2 patients who received high dose chemotherapy and stem cell rescue (33%) were alive at the time of last follow-up (at 30 months and 12 months, respectively). Including the patients reported in the current study, 9 of 15 children with NK cell lymphoma (all stages) (60%) were reported to be alive at the time of last follow-up. CONCLUSIONS: Although pediatric NK cell lymphomas rapidly can become fatal, it appears that high dose chemotherapy followed by stem cell transplantation is effective therapy, especially in patients with advanced or resistant disease. Further follow-up is needed to determine whether this treatment approach will be curative.

Antineoplastic Combined Chemotherapy Protocols↗

Peripheral blood stem cell transplantation in young children: experience with harvesting, mobilization and engraftment.

The purpose of this study was to determine the feasibility and assess optimal timing of harvesting peripheral blood stem cells (PBSC) for transplantation in young children. Thirteen children with body weight less than 25 kg, mean age of 3.9 years (1-9 yrs) who had recurrent solid tumors and leukemia were given tumor specific chemotherapy followed by i.v. rhG-CSF (5 microg/kg/d) for stem cell mobilization. Cytaphereses were done through a central venous line (CVL) during the marrow recovery phase (WBC >0.5 x 10(9)/l). The phereses were analyzed separately and assigned to three groups depending on the WBC at the time of the pheresis: Group I (WBC <1.0 x 10(9)/l), Group II [WBC in the range 1.0-3.0 x 10(9)/l] and Group III (WBC >3.0 x 10(9)/l). Samples from each harvest were assayed for cell count, CFU-GM, BFU-E, CD34+ cell count, and tumor cell immunocytology in patients with neuroblastoma (NBL). A median of 3.2 x 10(8) mononuclear cells per kg (MNC/kg), [mean 2.8 x 10(8) MNC/kg, standard error of the mean (SEM) +/- 0.74 (1.1-4.7)] were infused following myeloablative therapy. 78 phereses were performed in 13 children with a median weight of 18 kg (10-25 kg). A median of 5 phereses were performed per patient. There were no significant differences in the percentage and number of CD34+ cells, CFU-GM or BFU-E colonies assayed by plating 0.5 x 10(5) cells. Differences could be found in the total number of MNC (p<0.008) and the number of MNC/kg (p<0.001) between Groups II and III. No tumor cell contamination was detected in the NBL patients by immunocytology. All patients were rescued with PBSC and achieved sustained white cell engraftment (ANC >0.5 x 10(9)/l) at a median of 13.5 d (10-25 d) and platelet engraftment (untransfused platelet count >20.0 x 10(9)/l) at a median of 29 d (12-63 d). The only toxicity encountered during the phereses was thrombocytopenia in 4 patients whose median post-pheresis platelet count was 6.0 x 10(9)/l (3.0-9.01). It is concluded that collection of PBSC in young children is feasible and safe and can be performed through a cuffed CVL at the time of WBC recovery post mobilization with chemotherapy and G-CSF. Cytopheresis can be effectively performed when the peripheral WBC count approaches 1.0 x 10(9)/l. Following stem cell infusion, engraftment was prompt and durable.

Adolescent↗

Serum erythropoietin levels in children with leukemia.

OBJECTIVE: Our aim was to test the hypothesis that, in leukemic children, serum erythropoietin (EPO) levels vary inversely with hemoglobin. DESIGN: Twenty-four children (15 males, nine females) with an age range of 1-16 years (mean, 7.7 years) diagnosed with acute leukemia (22 acute lymphocytic, two acute myeloid) were studied over 4 months. Serum EPO and hemoglobin were measured simultaneously at multiple time points in the course of their disease, and a multiple regression analysis was performed to describe the EPO-hemoglobin relationship. RESULTS: In a model adjusted for individual subject, there was a significant correlation between hemoglobin and logEPO in these leukemic children (r = -0.55, P < .01, n = 100). When measurements at hemoglobins less than 10.0 were analyzed the correlation increased significantly (r = -0.88, P < .01, n = 21). However, approximately 20% of the observations fell into one of two groups: an inappropriately low EPO for hemoglobin or an inappropriately elevated EPO for hemoglobin. The clinical characteristics of the children at each of these determinations were not different in any manner from the determinations which fell within the 95% confidence intervals for predicted mean EPO value: each of the outlying points came from a patient who at other times had an appropriate EPO for hemoglobin. CONCLUSIONS: There existed a significant inverse relationship between hemoglobin and EPO, suggesting that the feedback mechanism for EPO is intact. Reasons for inappropriately high or low EPO, for level of hemoglobin, are not clear and may be reflective of other aspects of bone marrow or EPO metabolism.

Acute Disease↗

Prior fungal infection is not a contraindication to bone marrow transplant in patients with acute leukemia.

PURPOSE: Our aim was to assess the feasibility of bone marrow transplantation (BMT) in patients with acute leukemia who have had prior documented invasive fungal infection within 5 months pretransplant treated aggressively with systemic amphoteric in B and, when applicable, surgical resection of the infected tissue. MATERIALS AND METHODS: We reviewed the charts of patients with acute leukemia at our institution who underwent BMT between August 1992 and April 1994 after being treated for a severe fungal infection. We evaluated criteria for diagnosis of fungal infection, timing of infection in relation to BMT, and antifungal treatment modalities. We determined peritransplant complications, evidence for recurrence of fungal infection during BMT, morbidity related to antifungal drug therapy, and overall outcome in each patient. RESULTS: Fungal infection developed in eight patients. Sites of involvement included lung, liver, spleen, and skin. All patients were treated with systemic amphotericin B. Some also underwent surgical resection of infected tissue following clinical control of infection. All patients underwent BMT. Seven of eight patients engrafted and survived BMT. One patient died of recurrent pulmonary mucormycosis. Three patients are alive and free of leukemia and fungal disease. Four patients died of noninfectious causes and had no evidence of fungal disease at the time of death. CONCLUSIONS: Aggressive therapy of prior fungal infection followed by ongoing anti-fungal prophylaxis in acute leukemia patients may allow BMT without reactivation of the fungus. Reports of larger series of such patients as well as studies of the efficacy of chemoprophylaxis of fungal infections are needed.

Adolescent↗

Haploidentical related umbilical cord blood stem cell transplant in a child with acute non-lymphocytic leukemia.

Umbilical cord blood stem cells (UCBSC) were used to reconstitute hematopoiesis following myeloablative therapy in a 13-month-old infant with acute nonlymphocytic leukemia (ANLL):FAB-M5 who had failed to sustain a chemotherapeutic remission. The patient's mother was 18 weeks pregnant with her second child at the time of diagnosis. Amniocentesis revealed that the fetus was HLA-haploidentical with the patient at the paternally inherited allele. The umbilical cord blood was harvested and processed by Ficoll centrifugation with 100% recovery of 5 x 10(7) mononuclear cells/kg and then cryopreserved. Two weeks after collection the cells were thawed and then infused into the patient following conditioning with total body irradiation, cyclophosphamide, and etoposide. Graft-versus-host-disease (GVHD) prophylaxis consisted of cyclosporine and methotrexate. The patient experienced clinical grade I GVHD consisting of skin involvement only that resolved within 2 weeks following the addition of corticosteroids. Engraftment was achieved with an absolute neutrophil count (ANC) above 0.5 x 10(9)/l on day 16, a platelet count above 50 x 10(9)/l on day 56, platelet transfusion independence on day 32 and red blood cell transfusion independence after day 44. Three months following transplantation restriction fragment length polymorphism (RFLP) revealed no discernible difference between the donor and the recipient. The patient remains in remission without evidence of GVHD 23 months post-transplant.

Antineoplastic Combined Chemotherapy Protocols↗

Treatment of poor-risk neuroblastoma patients with high-dose chemotherapy and autologous peripheral stem cell rescue.

A single institutional pilot study was conducted in which 12 poor-risk neuroblastoma (NB) patients were uniformly treated with multi-agent induction chemotherapy followed by myeloablative consolidation chemotherapy and unpurged peripheral blood stem cell (PBSC) rescue. In addition to using standard criteria for evaluating response to induction chemotherapy, tumor cell contamination of the peripheral blood and/or bone marrow was analyzed in seven patients by immunocytology using a panel of five anti-NB monoclonal antibodies. Seven patients had morphologic evidence of bone marrow disease at the time of diagnosis, and two additional patients had tumor cells detected in bone marrow samples by immunocytology prior to the second cycle of chemotherapy. After three cycles of chemotherapy, two of the 12 patients continued to have evidence of bone marrow disease. Samples from 29 PBSC harvests collected from nine patients were also analyzed for the presence of contaminating tumor cells by immunocytology. In each case, the stem cells were found to be free of tumor. Eleven of the 12 patients underwent myeloablative therapy and PBSC rescue; five patients remain alive without disease progression, 28+ to 53+ months from diagnosis, and six patients have developed recurrent disease. We conclude that PBSCs can be successfully harvested from children with NB, and used for hematopoietic reconstitution following myeloablative chemotherapy. However, more effective therapy for poor-risk NB patients is still urgently needed.

Adult↗

Teaching communication skills. An essential part of residency training.

OBJECTIVE: To design a structured curriculum concerning issues of communication with patients and families for use during training of pediatric residents. BACKGROUND: The stimulus for this initiative arose from residents perceived need for such a program and the realization that a structured approach to communication techniques did not currently exist in our residency and, in fact, in many undergraduate and graduate medical education curricula. METHODS: Our program was designed to address complex and difficult areas in physician-patient interaction, including how to deliver "bad news," deal with hostile parents, and speak to children about serious illness; the psychosocial aspects of death and dying were also covered in the program. Various teaching techniques were used. We attempted to assess residents' response and alteration in behavior consequent to the program. RESULTS: The program was successfully incorporated into the training of our residents and was carried out by using existent personnel; minimal expense was incurred. The residents thought the course was valuable and effective, although no statistically significant change in the communication skills of residents could be demonstrated. CONCLUSIONS: The area of physician-patient communication can be taught in a structured fashion during residency. Programs should be devised to meet the changing needs of training during residency and should incorporate the unique strengths of individual institutions.

Adult↗

Pancreatic blastomatous tumor in a child responding to therapy used for hepatoblastoma: case report and review of the literature.

A case is reported of a 7-year old girl diagnosed with initially inoperable metastatic embryonic pancreatic tumor, which showed a significant clinical response to chemotherapeutic agents commonly used to treat hepatoblastoma. This regimen was selected because certain histologic features of the tumor demonstrated characteristics seen in hepatic tissue. After two course of chemotherapy (cis-platinum and adriamycin), there was a significant reduction of the primary mass, and it was completely resected, although the tumor subsequently recurred in the metastatic, unoperated site. The embryological relationship between the tumor in this patient and hepatoblastoma, as well as the literature concerning treatment in pediatric pancreatoblastic tumors are reviewed. Complete eradication of tumor appears to be necessary for cure.

Antibiotics, Antineoplastic↗

Pyomyositis during induction chemotherapy for acute lymphocytic leukemia.

PURPOSE: Pyomyositis is a rare disease in temperate climate regions and frequently has a subacute presentation. Because of this, the entity is often misdiagnosed. PATIENTS AND METHODS: Two boys with acute lymphocytic leukemia (ALL) who presented with muscle pain, shortly after receiving induction chemotherapy, were evaluated. RESULTS: Presenting physical examination and laboratory findings were unremarkable except for extremity pain and tenderness. These symptoms were initially attributed to a neurotoxic side effect of vincristine. As the children's symptoms progressed, muscle abscess formation was finally delineated by gallium and computed tomography scans, and the diagnosis of pyomyositis was made. In both cases, the invading organism was Staphylococcus aureus. Both children responded well to incision and drainage of the abscesses and antibiotic therapy. CONCLUSION: Four cases of pyomyositis occurring in ALL patients shortly after induction chemotherapy have now been described. We feel that when children from this population present with muscle pain, pyomyositis should be part of the differential diagnosis. With early medical and surgical intervention, morbidity and mortality can be avoided.

Abscess↗

Prenatal detection of neuroblastoma by fetal ultrasonography.

PURPOSE: We report three cases of neuroblastoma diagnosed by prenatal ultrasound examination and examine the biologic features of tumors diagnosed prenatally. PATIENTS AND METHODS: Neuroblastoma is the most common tumor detected in the newborn period. Thus, some of these tumors develop prenatally and should be detectable by maternal ultrasound. Here we report three cases in which a neuroblastoma was suspected on prenatal ultrasonography. In addition, we review selected features of 17 additional cases reported in the literature. RESULTS AND CONCLUSIONS: These data indicate that, although the majority of patients have favorable clinical and biological features and do well, some patients do not, and the DNA index may be the most important predictor of outcome.

Female↗

Renal functional reserve in long-term survivors of unilateral Wilms tumor.

We hypothesized that long-term survivors of unilateral Wilms tumor would have a decreased renal functional reserve secondary to the consequences of hyperfiltration in the nephrons of the remaining kidney. Therefore we evaluated the renal functional reserve in 12 long-term survivors of Wilms tumor after unilateral nephrectomy (mean +/- SE: 15 +/- 1.1 years; range 9 to 23 years). We measured the creatinine clearance before and after an acute, oral protein load to determine the renal functional reserve. Study subjects and control subjects were matched for age, gender, and body surface area. The basal creatinine clearances were similar (Wilms group 132 +/- 13 vs control group 142 +/- 11 ml/min/1.73 m2; p = not significant (NS]. There was no significant difference in the renal functional reserve between long-term survivors of Wilms tumor and matched control subjects (Wilms group 17 +/- 11 vs control group 25 +/- 11 ml/min/1.73 m2; p = NS). The change in creatinine clearance was not secondary to volume expansion because the fractional excretion of sodium was unchanged with protein loading (Wilms group before loading 0.92 +/- 0.12 vs after loading 0.99 +/- 0.13 (p = NS); control group before loading 0.91 +/- 0.12 vs after loading 1.0 +/- 0.14 (p = NS)). We conclude that up to 15 years after nephrectomy for unilateral Wilms tumor in childhood, there is no evidence of hyperfiltration injury.

Adolescent↗