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Biomedical subjects

M Horn

Publications and source records attributed to M Horn.

At least 145 records · Page 8Linked to original sources

Cancer chemotherapy after solid organ transplantation.

To assess how well chemotherapy is tolerated after solid organ transplantation, we reviewed our experience at the Children's Hospital of Pittsburgh with five patients aged 1 to 12 years. Four patients had a liver transplant, indications for which were hepatoblastoma in two patients, hepatic failure secondary to Wilms' tumor chemoradiotherapy in one patient, and familial intrahepatic cholestasis in one patient. A fifth patient received a cardiac transplant for unresectable angiosarcoma of the right atrium. After transplant, chemotherapy was given for the treatment of the primary malignancy in four of the patients. The patient with familial intrahepatic cholestasis received chemotherapy for secondary lymphoproliferative disease that had not responded to the cessation of immunosuppression. All patients other than this patient were on immunosuppression with prednisone (0.5 to 2 mg/kg daily) and cyclosporine (to maintain serum levels at 800 to 1000 ng/ml radioimmunoassay) throughout the duration of chemotherapy. Courses of chemotherapy included one or more of the following agents: Adriamycin (Adr, 20 mg/m2 daily, three patients), Cyclophosphamide (Ctx, 1 gm/m2, one patient), cisplatin (CDDP, 90 mg/m2, one patient), Vincristine (Vcr, greater than 0.75 to 1.5 mg/m2, three patients), Actinomycin D (Act-D, 7.5 micrograms/kg, one patient), Ifosfamide (I, 1800 mg/m2, one patient) and Etoposide (VP-16, 100 mg/m2, one patient). All patients received greater than or equal to 3 courses (range, 3 to 9; mean, 5) of chemotherapy every 3 to 4 weeks. Dose reductions were made because of neutropenia in three patients but none were greater than 50%. Severe rejection was seen in one patient who had, however, manifested evidence of rejection prior to his first postoperative course of chemotherapy. No nephro or cardiac toxicity was seen. This preliminary experience suggests that chemotherapy is well tolerated after solid organ transplantation.

Adolescent↗

Neuronal pathways in the guinea-pig lumbar sympathetic ganglia as revealed by immunohistochemistry.

Tyrosine hydroxylase (TH)- and peptide-immunoreactivity of postganglionic neurons and of nerve fibres in guinea pig lumbar paravertebral sympathetic ganglia 2-4 after transection of the communicating rami and the visceral branches, respectively, were investigated by single- and double-labelling techniques. Six subpopulations of postganglionic neurons were discriminated immunohistochemically: two cell types, which were immunoreactive to only one of the applied antisera - TH, and vasoactive intestinal polypeptide (VIP); and four cell types in which immunoreactivity was colocalized - TH/neuropeptide Y (NPY), NPY/VIP, dynorphin/alpha-neoendorphin and dynorphin (alpha-neoendorphin)/NPY. Small intensely fluorescent (SIF) cells dependent on their location exhibited differential immunobehaviour to NPY-/dynorphin-(alpha-neoendorphin-) and TH-antisera. Immunoreactivity to substance P (SP), calcitonin gene-related peptide (CGRP), met-enkephalin-arg-phe (MEAP) and leu-enkephalin was present in nerve fibres but not in postganglionic neurons with frequent colocalization of SP/CGRP- and MEAP/leu-enkephalin- and, sometimes leu-enkephalin/SP- and dynorphin/SP-immunoreactivity. TH-immunoreactive intraganglionic nerve fibres were numerically more increased after cutting the visceral branches, than after transection of the communicating rami. Vice versa, NPY-, VIP-, dynorphin- and alpha-neoendorphin-immunoreactive nerve fibres were particularly increased in number after cutting the communicating rami. Many but not all of the nerve fibres exhibited colocalization of two of these peptides. SP-, CGRP-, and enkephalin-immunoreactive nerve fibres were not visibly affected by cutting the visceral branches but virtually disappeared after lesioning the communicating rami.

Animals↗

Severe chemotherapy-related hepatic toxicity associated with MZ protease inhibitor phenotype.

We describe a 10 1/2-month-old boy in whom fulminant hepatic failure following chemotherapy for Wilms' tumor developed. He then received an orthotopic liver transplant. An unexpected finding was the accumulation of alpha 1-antitrypsin (AAT) in periportal hepatocytes. A pretransplant serum sample showed a Pi MZ phenotype. The rarity of hepatic failure following treatment for Wilms' tumor raises the possibility of an increased susceptibility to toxic injury in the presence of AAT accumulation. Determination of the frequency of protease inhibitor MZ phenotype in patients who have chemotherapy-related hepatotoxicity could be used to initiate a prospective study aimed at identifying an at-risk population for chemoradiotherapy-related hepatoxicity.

Alleles↗

[Waterhouse-Friderichsen syndrome in adults].

Only a minority of published cases of Waterhouse-Friderichsen-syndrome occurred in adults (Harms et al., 1973). At the autopsy of a 23 years old woman there were found sugillations of the eyelid, of the peri- and epicard, of the serosa of the small intestine and of the lung. In the region of the adrenal gland a brownish-red mass was detectable. Histologically an adrenal apoplexy with necrosis and in liver, spleen and lung a lot of neutrophils were seen. Streptococcus viridans was pointed out in the blood.

Adrenal Cortex↗

[The Wilcoxon, Mann and Whitney test: conditions under which and hypotheses for which it is applicable].

The test of Wilcoxon, Mann and Whitney is applicable only under the assumption that the two distribution functions FX and FY do not intersect. In case of doubt this assumption should be examined by drawing the estimates of FX and FY. If the assumption is true, the test simultaneously examines whether X and Y have equal means, equal medians, and whether 'X greater than Y' and 'Y greater than X' have the same probability 1/2. Independent of the assumption one concludes 'FX not equal to FY' in case of significance and 'P(X greater than Y) = 1/2 in case of no significance and large sample sizes. If the assumption may be violated, no statement is possible concerning means or medians. The probability P(X greater than Y) can be compared even against some p0 (being possibly different from 1/2), and a confidence interval for P(X greater than Y) can be calculated, when using the large sample modification of the test by Hilgers (1981).

Animals↗

Thrombocytosis as a presenting feature of acute lymphoblastic leukemia in childhood.

To determine the incidence of thrombocytosis at presentation in acute lymphoblastic leukemia (ALL), medical records of all children diagnosed at the Children's Hospital of Pittsburgh from 1980 to 1987 were reviewed. Out of 217 such patients, 7 (3.2%) had platelet counts greater than 400,000/mm3. All of the seven were boys compared with a male:female ration of 1.4:1 in the entire ALL population. Other than sex, no characteristics were clearly associated with thrombocytosis, including white blood cell count, hemoglobin, lymphoblast morphology, and immunologic or chromosomal markers. Apart from ALL, no inflammatory or infectious process which might have caused a thrombocytosis, was detected in any of these patients. The period of induction therapy was notable for the preservation of platelet counts greater than 20,000/mm3 in all patients. However, of the seven children with thrombocytosis, two had major induction complications: one, a cavernous sinus thrombosis; and the other, gastrointestinal bleeding with duodenal perforation. We conclude that thrombocytosis at diagnosis can be seen in children, particularly boys, with ALL. Based on small numbers, this group of patients may be at risk for major events during induction therapy. Large numbers, longer follow-up, and platelet function studies on similar patients will be of interest.

Biopsy↗

Possible association of sudden infant death with partial complement C4 deficiency revealed by post-mortem DNA typing of HLA class II and III genes.

Based on evidence of an increased rate of respiratory infections in sudden infant death (SID) infants as well as the observation of familial occurrence, we analysed in a retrospective study class II and class II genes of the major histocompatibility complex in 40 cases of SID by Southern blot analysis of DNA obtained post mortem from tissue samples. In 24 cases, the parents were interviewed and confirmatory human lymphocyte antigen (HLA) and DNA typing was carried out. Using HLA-DR beta and -DQ beta probes, no evidence of an abnormal HLA-DR frequency distribution in SID infants was detected (P = 0.97). Using DNA probes for the tandemly arranged complement C4 and steroid 21-hydroxylase genes, an increased number of C4B gene deletions in SID cases was found. The increase in C4 gene deletions was significant (P = 0.0125) in infants with recurrent infections. These data indicate a possible role of partial C4 deficiency as a genetically predisposing risk factor in SID.

Complement C4↗

Economic motivation for smoking cessation in chronic psychotic patients.

For many chronic psychotic patients the sole motivation to discontinue tobacco smoking may involve economic reasons. As institutions increasingly adopt no-smoking policies, economic motives for smoking cessation may take on added importance in assisting this population with smoking cessation.

Adult↗

Rhabdomyosarcoma in Roberts syndrome.

A 23-month-old child diagnosed as having Roberts syndrome, born to consanguineous parents, developed a sarcoma botryoides. Cytogenetic evaluation of peripheral blood lymphocytes and tumor cells showed premature centromere separation, which is characteristic of Roberts syndrome.

Abnormalities, Multiple↗

Krypton-81m imaging of the right ventricle.

We report the development of a method for obtaining right-ventricular radionuclide angiograms using continuous peripheral intravenous infusion of the ultra-short-lived nuclide krypton-81m. This tracer has a half-life of 13 sec, emits a single 190-keV photon, and is extremely insoluble. During infusion into a peripheral vein, Kr-81m achieves stable count rates over the right heart, and it is essentially completely cleared by the lungs during its initial pulmonary transit. Thus no interfering activity is present in the systemic circulation. Initial studies provide excellent data on right-heart anatomy and function.

Heart↗

[A statistical method for the determination of the yield correlation of antibiotic-producing microorganisms].

The antibiotic yields of industrial selectants must be checked at several steps of cultivation. Here the question arises whether the activities at the different levels of cultivation are correlated. The common coefficient of correlation cannot be used because repeated determinations of the yield at one selectant result in different values. In order to have only one fixed value per selectant we define the mean value around which the observed values are varying. But these mean values cannot be observed. Thus, an adequate method of correlation similar to that in Guiard and Herrendörfer (1977) was used. The method is demonstrated in two examples: With selectants of Streptomyces noursei for streptothricin titers in 20 ml- and 20 l-cultures as well as with selectants of Penicillium chrysogenum for potency indices in surface cultures and penicillin titers in 50 ml submerged cultures, respectively. In both cases the coefficients of correlation were above 0.7.

Anti-Bacterial Agents↗

Restrictive ventilatory pattern in precapillary pulmonary hypertension.

Patients with precapillary pulmonary hypertension (PPH) have classically been reported to have normal pulmonary mechanical function. We reviewed spirometric data from 8 patients with primary pulmonary hypertension and from 17 patients with chronic thromboembolic pulmonary hypertension. All patients had undergone right heart catheterization and pulmonary angiography. Five of the 8 patients with primary pulmonary hypertension demonstrated a severe restrictive ventilatory pattern with a mean vital capacity (VC) of 50.4% predicted and a mean total lung capacity (TLC) of 64.3% predicted. Five of the 17 patients with chronic thromboembolic pulmonary hypertension manifested a restrictive pattern with a mean VC of 68.0% predicted and a mean TLC of 75.3% predicted. We conclude that restrictive ventilatory defects occur more frequently than previously described in patients with PPH. The physiologic mechanism responsible for the restrictive ventilatory pattern is not clear.

Adult↗