Distribution of peroxisomes (microbodies) in the nephron of the rat: a cytochemical study.

The distribution of peroxisomes (microbodies) in the rat nephron was studied cytochemically, using glutaraldehyde- or formaldehyde-fixed tissue, by means of alpha-hydroxy acid oxidase activity in light microscopy or oxidation of 3,3'-diaminobenzidine (DAB) at pH 9 in both light and electron microscopy.The two cytochemical methods show peroxisomes to be nearly sperical particles found only in cells of the proximal convoluted tubule. Lysosomes were identified in the same or parallel sections, with beta-glycerophosphate or 5'-cytidylic acid as substrate. They are found in all cells of the nephron. These cytochemical methods visualize the two organelles for light microscopy; they also permit unequivocal differentiation of all kidney peroxisomes from lysosomes in electron micrographs. Peroxisomes are larger and more reactive in the cells of the pars descendens (P(3) segment) of the proximal convolution, located in the outer medulla and medullary rays, than in the cells of the pars convoluta (P(1) and P(2) segments), situated in the cortex. In contrast, lysosomes are much smaller in the P(3) segment and larger and more reactive in the P(1) and P(2) segments. In all cells of the proximal convolution, peroxisomes tend to be concentrated nearer the base of the cells than do lysosomes. Mitochondria in P(3) cells also show low levels of DAB oxidation at pH 6, in contrast to those in P(1) and P(2) cells. The possibility is discussed that P(3) cells possess an extramitochondrial means of oxidation in which peroxisome oxidases play an important role.

Conversion of vitamin B 6 compounds to active forms in the red blood cell.

In studies with pyridoxine and other B(6) compounds in blood, the active forms pyridoxal and pyridoxal phosphate were measured by differential assays using Lactobacillus casei. Red cell uptake of tritiated pyridoxine was also measured. A new metabolic pathway for conversion of pyridoxine to active forms was demonstrated in red cells. In vivo studies in normal subjects suggested that pyridoxine was taken up by red cells where it was converted to pyridoxal phosphate and then pyridoxal, followed by gradual release of a proportion of pyridoxal into plasma. In vitro incubation of pyridoxine with blood confirmed this observation. Increasing amounts of pyridoxine were taken up and converted as the amount added to blood was increased, and only very small numbers of red cells were needed to convert appreciable amounts. Conversion was markedly inhibited at temperatures lower than 37 degrees C, and stopped altogether at - 20 degrees C.Release of pyridoxal into plasma was always directly proportional to the amount of pyridoxal formed and to the volume of plasma present. That pyridoxal phosphate was not released into plasma was demonstrated in stored blood, for pyridoxine was converted mainly only as far as pyridoxal phosphate, probably due to inactivation of the phosphatase. Pyridoxal phosphate remained in the red cells. Pyridoxine was converted when incubated with washed red cells in saline or phosphate buffer suspension (0.08 M). In saline suspension, pyridoxal formed but was not released in the absence of plasma. In phosphate buffer suspension, pyridoxal phosphate was formed but was not changed to pyridoxal, probably due to inactivation of phosphatase by excess phosphate. Pyridoxamine was converted to active forms in red cells less efficiently. Pyridoxal entered red cells rapidly, equilibrating between plasma and cells within 1 min in the same ratio as pyridoxal formed inside red cells. Pyridoxal phosphate did not enter red cells in whole blood but did so readily in washed cells in saline.

Peroxisomal bifunctional enzyme deficiency.

Peroxisomal function was evaluated in a male infant with clinical features of neonatal adrenoleukodystrophy. Very long chain fatty acid levels were elevated in both plasma and fibroblasts, and beta-oxidation of very long chain fatty acids in cultured fibroblasts was significantly impaired. Although the level of the bile acid intermediate trihydroxycoprostanoic acid was slightly elevated in plasma, phytanic acid and L-pipecolic acid levels were normal, as was plasmalogen synthesis in cultured fibroblasts. The latter three parameters distinguish this case from classical neonatal adrenoleukodystrophy. In addition, electron microscopy and catalase subcellular distribution studies revealed that, in contrast to neonatal adrenoleukodystrophy, peroxisomes were present in the patient's tissues. Immunoblot studies of peroxisomal beta-oxidation enzymes revealed that the bifunctional enzyme (enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase) was deficient in postmortem liver samples, whereas acyl-CoA oxidase and the mature form of beta-ketothiolase were present. Density gradient centrifugation of fibroblast homogenates confirmed that intact peroxisomes were present. Immunoblots of fibroblasts peroxisomal fractions showed that they contained acyl-CoA oxidase and beta-ketothiolase, but bifunctional enzyme was not detected. Northern analysis, however, revealed that mRNA coding for the bifunctional enzyme was present in the patient's fibroblasts. These results indicate that the primary biochemical defect in this patient is a deficiency of peroxisomal bifunctional enzyme. It is of interest that the phenotype of this patient resembled neonatal adrenoleukodystrophy and would not have been distinguished from this disorder by clinical study alone.

Geographical distribution of acute lymphoblastic leukaemia subtypes: second report of the collaborative group study.

Childhood acute lymphoblastic leukemia (ALL) T and B precursor subtypes have been identified by standardised immunophenotyping in different geographic and ethnic settings. Comparison of the relative frequencies and estimated incidence rates of the major subtypes indicates very similar values, with the striking exception of black childhood populations in Africa in which there appears to be a significant and selective deficit in the incidence of the common (B-cell precursor) subset of ALL. There is suggestive evidence for a similar bias in ALL subtypes in South Africans of mixed ethnic origin and in Mapuche Indians from Chile. Several interpretations of these data are possible but the one favoured attributes these differences primarily to socio-economic factors and patterns of infection in infancy.

Intranasal amphotericin B reduces the frequency of invasive aspergillosis in neutropenic patients.

PURPOSE: To retrospectively study the prophylaxis of invasive aspergillosis in neutropenic patients and to relate the frequency of this fungal disease to any causal or modifying factors that could be identified. PATIENTS AND METHODS: Between 1977 and 1988, 130 patients underwent 158 intensive treatment episodes to control acute leukemia, lymphoma, and aplastic anemia, and the frequency of complicating aspergillus infection was determined. RESULTS: Proven invasive aspergillus infections occurred in 22 cases, 12 of which were fatal. Invasive aspergillosis was suspected in a further 16 cases and all these patients recovered with amphotericin B treatment. Colonization by Aspergillus in the absence of clinically significant infection was seen in 31 treatment episodes. Invasive aspergillosis involved mainly the upper and lower respiratory tract and skin. Control of the infection was closely related to the control of the underlying disease, with subsequent return of normal marrow function and resolution of neutropenia. The incidence of aspergillus infection has decreased dramatically since 1985, most probably due to the introduction of intranasal amphotericin B. This occurred despite the persistence of aspergillus spores in the hematology ward air during the 1986 to 1988 period. CONCLUSION: Intranasal aerosolized amphotericin B may protect against invasive aspergillosis, even when neutropenic patients are cared for in conventional wards without HEPA filtration.

The effect of donor pretreatment on interstitial dendritic cell content and rat cardiac allograft survival.

Different pretreatment schedules were applied to rat heart donors and their effect on heart interstitial dendritic cell content was observed using monoclonal antibodies and immunofluorescence techniques. Interstitial dendritic cell (IDC) numbers were correlated with the histology and survival of hearts transplanted into untreated allogeneic recipients. Hearts from AS donors pretreated with cyclophosphamide and total-body irradiation showed prolonged survival in DA recipients only when more than 95% of the graft interstitial dendritic cells were depleted. Reconstitution studies established that prolonged graft survival following donor pretreatment depended on the removal of bone-marrow-derived cells and that these were IDCs. These results suggest that the IDC is the most significant "passenger leucocyte", and that very small numbers of residual IDCs were still sufficient to cause rapid rejection. DA rat heart contained three times as many IDCs as the AS strain and DA hearts were much more difficult to deplete of IDCs. Pretreated DA hearts were rejected by AS recipients, although grafts with a lower IDC content resulted in an attenuated histological rejection response and a markedly decreased recipient lymphocytotoxin response. To be effective, donor pretreatment schedules had to be initiated 5 days prior to transplantation. Pretreatment 6 hr prior to transplantation failed to deplete IDC or prolong graft survival even in he weak (ASxDA)F1 to DA model. Pretreatment protocols used clinically have probably not removed IDCs adequately and the development of methods that deplete IDCs effectively could improve graft survival at no risk to the recipient.

D-aspartate oxidation by rat and bovine renal peroxisomes: an electron microscopic cytochemical study.

D-amino acid oxidase, a peroxisomal enzyme, and D-aspartate oxidase, a potential peroxisomal enzyme, share biochemical attributes. Both produce hydrogen peroxide in flavin-requiring oxidative reactions. Such similarities suggest that D-aspartate oxidase may also be localized to peroxisomes. Definitive identification of D-aspartate oxidase as a peroxisomal enzyme depends, however, on visualization at the electron microscopic level. Using incubation conditions shown to be specific for the enzyme in biochemical studies, this report extends the cytochemical localization of D-amino acid oxidase to bovine renal peroxisomes, and shows that D-aspartate can be oxidized by rat and bovine renal peroxisomes. An unexpected finding was the sensitivity of both D-amino acid oxidase activity (proline specific) and D-aspartate oxidase activity to inhibition by agents used in biochemical studies to discriminate between the two enzyme activities. Therefore, it is possible that, in the cytochemical system used in this study, (a) either D-proline and D-aspartate are substrates for only one enzyme or (b) the two enzymes have additional overlapping biochemical properties.

Peroxisomes in pulmonate gastropods.

Organelles with the morphologic characteristics of peroxisomes have been found in the cells of the kidney sac of two terrestrial pulmonate gastropods. Arion ater and Ariolimax columbianus. These peroxisomes appear in profile as circles or ellipses, 0.25 micron in diameter and 0.3-0.8 micron long; They have a finely granular matrix and a single-limiting membrane; the organelles are extensively associated with smooth endoplasmic reticulum. Some Ariolimax peroxisomes contained structures reminiscent of nucleoids while those of Arion did not. The peroxisomes of Arion ater show a strongly-positive staining reaction with the 3,3'-diaminobenzidine technique, which is inhibited in the presence of aminotriazole. Peroxisomes of Ariolimax columbianus did not show a positive reaction, despite a number of variations of the 3,3'-diaminobenzidine protocol. Speculations are made concerning the biochemical reasons for this cytochemical behavior. Peroxisomes in both tissues were negatively stained while lysosomes were positively stained in acid-phosphatase incubations.

Peroxisomes in fibroblasts from skin of Refsum's disease patients.

Skin fibroblasts were cultured from young adult patients with Refsum's disease, an inherited metabolic disorder characterized by a deficiency in oxidation of phytanic acid and by increased serum and tissue concentrations of this fatty acid. These cultures were compared to cultures of normal fibroblasts in terms of the number and distribution of peroxisomes demonstrable cytochemically in preparations incubated for catalase activity. Refsum's fibroblasts were found to contain 1-10 peroxisome profiles per 100 micron 2 of cytoplasm; the controls contained 1-2 profiles per 100 micron 2. The peroxisomes in normal fibroblasts were found in all regions of the cytoplasm. In the Refsum's material they were relatively scarce in the perinuclear region, where many of the cells showed numerous large inclusions containing lipid-like material and myelin figures. Our findings indicate that in the adult form of Refsum's disease, which is the more thoroughly studied variety, peroxisomes in fibroblasts are not diminished in number. This contrasts with a recent report concerning a case of what is thought to be an infantile form of the disorder, in which no peroxisomes were detected in a liver biopsy. If phytanic acid accumulations in the adult form are a consequence of peroxisomal defects, the defects presumably are at the level of specific enzymatic deficiencies and do not involve a generalized absence of peroxisomes.

Oxidation of oxalate and polyamines by rat peroxisomes.

During renal failure, polyamines and oxalate levels are elevated in the serum and the glomerular filtrate and are dumped by the kidney. Both of these compounds can be catabolized by oxidative reactions. We have, therefore, investigated the intracellular distribution of oxalate oxidase and of a polyamine oxidase in normal female rat kidney and liver. Polyamine oxidase was demonstrable, using spermidine as substrate in the cerous peroxyhydrate procedure of Briggs et al., in peroxisomes of kidney tubule cells and of hepatocytes. Oxalate oxidase could not be studied with this technique due to precipitation of cerium oxalate in the incubation medium. To demonstrate oxalate oxidase, and to confirm the polyamine oxidase localization, we incubated aldehyde-fixed tissue in a diaminobenzidine medium at pH 8, following the approach of Veenhuis et al., in which oxidases are demonstrated by virtue of their production of H2O2, which then serves as a substrate for endogenous catalase. Using oxalate or spermidine as substrate with this approach, we found reaction product in typical renal peroxisomes; we also found reaction product, with the polyamine substrate, in hepatocyte peroxisomes. To strengthen the conclusion that the oxidases themselves are present in peroxisomes, we used a light microscopic method, based on the tetrazolium procedures of Allen and Beard to demonstrate polyamine and oxalate oxidase activities in bodies with the distribution of renal peroxisomes.

Busulphan/cyclophosphamide conditioning for bone marrow transplantation may lead to failure of hair regrowth.

Following the introduction of bulsulphan and cyclophosphamide (BUCY) conditioning in our unit in 1987, a number of patients noted incomplete scalp hair regrowth following bone marrow transplantation (BMT). Between August 1987 and May 1989, 22 patients had undergone allogeneic or autologous BMT in our unit and we recalled for detailed assessment the 14 who were alive and well at least 6 months post grafting. Six patients had experienced incomplete hair regrowth of varying severity 7-27 months following BMT. All those affected had received BUCY conditioning and the four most severely affected were allogeneic BMT recipients. No patient had received any post-BMT chemotherapy or radiation. None of the patients had evidence of graft-versus-host disease. No laboratory test abnormalities distinguished the affected from the unaffected patients. Despite the relatively small number of patients, our results suggest that BUCY has caused permanent damage to the hair follicles of the affected patients. Prolonged alopecia may markedly impair the quality of life for long-term survivors of BMT and this unexpected complication also has significant medicolegal implications.

A community study of vitamin B12 and folate levels in the elderly.

OBJECTIVE: To measure the prevalence of low serum vitamin B12, folate, and red cell folate levels and their relationship with other nutritional indices. DESIGN: Prospective survey of elderly subjects using radioisotope dilution assays. SETTING: Primary care medical center, Christchurch, New Zealand. PATIENTS: 257 elderly subjects (age 65 years and over), residing in their own homes or in residential homes, were randomly selected. Of these, 204 (79%) participated. The study population was comparable to the elderly population of New Zealand. MAIN OUTCOME MEASURES: Vitamin B12, serum, and red cell folate levels. RESULTS: The prevalence rates for low levels of serum vitamin B12, folate, and red cell folate were 7.3%, 1%, and 3.3%, respectively. The elderly cohort had lower vitamin B12 (P less than 0.001) but higher serum and red cell folate levels (P less than 0.001) than our normal reference range (age 18-65 years). Red blood cell folate levels showed positive correlations with nutritional indices and mental test scores. No correlations were found between vitamin B12 levels and diet or other nutritional indices. CONCLUSIONS: Low folate levels in older people living at home are infrequent findings. In contrast low vitamin B12 levels are more common. Poor diet and undernutrition may contribute to low folate levels, but these factors are less important for the low B12 levels found.

Renal vein thrombosis in cases of polyarteritis nodosa and of the Henoch-Schoenlein syndrome.

The occurrence of renal vein thrombosis in a case each of polyarteritis nodosa and the Henoch-Schoenlein syndrome is reported. It is suggested that obliteration of the arterioles that supply the walls of the veins may have initiated the venous thrombosis in these two cases.

Haemoglobin A2 levels in vitamin B12 and folate deficiency.

Haemoglobin A2 levels were measured in 50 patients with vitamin B12 deficiency, 50 patients with folate deficiency, and six patients with combined deficiencies of these vitamins. All were normal except for three patients with vitamin B12 deficiency, who had a slightly elevated Hb A2 level; this fell to normal after vitamin B12 therapy. It is concluded that haemoglobin A2 levels are usually normal in vitamin B12 or folate deficiency. However, raised levels of haemoglobin A2 may be found, but these are not as high as is found in beta thalassaemia trait and should not cause difficutly in diagnosis.

Abnormal chromosome 16 in clonogenic eosinophils from a case of acute myeloid leukemia (FAB,M2).

A case of acute myeloid leukemia (AML, FAB M2) is described in which the leukemic karyotype showed several numerical and structural cytogenetic abnormalities including an abnormal chromosome 16 with breakpoint at band q22, monosomy for chromosomes 5 and 7, and a single pair of double minute chromosomes. There was no patient history of treatment for a previous malignancy or occupational exposure to mutagens. Bone marrow eosinophilia was seen at presentation for refractory anemia with excess blasts in transformation and when AML was diagnosed. When bone marrow buffy coat cells were cultured in soft agar in the presence of colony stimulating factor, 19% of the colonies and 20% of the clusters were of eosinophils. Cytogenetic examination of pooled eosinophil colonies showed the marker chromosomes that identified the leukemic population.

Cytogenetic studies of acute promyelocytic leukemia.

Translocation t(15;17) is reported in bone marrow cells from six of seven patients with active acute promyelocytic leukemia (APL). One patient who showed t(15;17) at final relapse did not show it in directly prepared or cultured cells taken from a previous relapse. Bone marrow samples from two patients showed only cells with a normal karyotype in the direct preparation, whereas more than 60% of cells cultured for 24 hr showed t(15;17). R-Banding, G-banding, and an attempt at high-resolution banding indicated the break points t(15;17)(q24;21) for one of our patients.

Nonrandom cytogenetic changes in New Zealand patients with acute myeloid leukemia.

Bone marrow clones with abnormal chromosomes were observed in 56% of 66 patients with forms of acute myeloid leukemia [French-American-British (FAB) M1-M6]. Acute myeloblastic leukemia (AML, M1 and M2) was the most common form, and 65% of these patients showed chromosomal abnormalities compared with 41% of patients with acute myelomonocytic leukemia (AMMoL, M4). The recognized nonrandom chromosomal abnormalities found were trisomy 8, monosomy 5 or 7, trisomy 1q, t(6;9), t(8;21), t(15;17), and abnormalities in 17q. There was also a strong involvement of chromosome No. 11: Abnormalities were found in eight patients when their leukemia was diagnosed and in a further three patients during the course of karyotypic evolution. Six of these patients had AMMoL or AMoL. Complex or multiple clones were found in 37% of AML patients at diagnosis. Our AML patients had a reduced frequency of abnormalities in chromosome No. 5 or 7 and an increased frequency of abnormalities in chromosome No. 8 compared with studies reported in other countries (p = 0.01). This difference suggests that in New Zealand AML might be caused by factors different from those operating in more industrialized centers.

Combination chemotherapy for advanced non-Hodgkin's lymphoma of unfavourable histology.

Thirty previously untreated adults with diffuse histiocytic and diffuse undifferentiated lymphoma were treated with a combination of adriamycin, vincristine, prednisolone, and L-asparaginase. Complete remission was achieved in 11 out of 12 cases with stage III and 7 out of 18 cases with stage IV disease (P less than 0.005). Bone marrow infiltration, clinical central nervous system involvement, and massive intra-abdominal disease all influenced the prognosis adversely. Complete remission was followed by cranial irradiation and intrathecal methotrexate, and maintained with weekly cyclophosphamide and methotrexate and daily 6-mercaptopurine. The duration of remission was significantly longer for patients with stage III disease (the median of which has not been reached), than for patients with stage IV disease (P = 0.007). Survival was significantly longer for patients in whom complete remission was achieved than for those in whom it was not (P = 0.001), and also for patients with stage III than for those with stage IV disease (P = 0.02).

Invasive aspergillosis in severely neutropenic patients over 18 years: impact of intranasal amphotericin B and HEPA filtration.

The impact of intranasal amphotericin B and high-efficiency particulate air (HEPA) filtration on the incidence of invasive aspergillosis was reviewed in patients from 1977 to 1994 undergoing intensive chemotherapy. Overall, the incidence of proven invasive aspergillosis was reduced from 24.4% (1977-1984) to 7.1% (1985-1991) (P < 0.001) following the introduction of intranasal prophylaxis, but when probable cases of aspergillosis were included and lymphoma cases excluded, there was no change in incidence. Following the introduction of HEPA filtration, patient exposure to aspergillus spores as measured by air sampling was markedly reduced and there were no new cases of invasive aspergillosis. HEPA filtration proved effective in reducing invasive aspergillosis and has allowed increasingly aggressive treatment regimens to be introduced.

The tissue distribution of the 3 alpha-fucosyl-N-acetyl lactosamine determinant recognized by the CD15 monoclonal antibodies CMRF-7 and 27.

Two monoclonal antibodies, CMRF-7 and 27, which react with cells of the granulocytic series, were obtained from hybridomas cloned from separate fusions. Biochemical studies indicate that both antibodies are of the CD15 group and react with the antigenic determinant 3 alpha-fucosyl-N-acetyl lactosamine (hapten X) expressed on some glycolipids and several different granulocyte glycoproteins with a wide range of molecular weights. The antigen was found on some promyelocytes and more differentiated granulocytes, including neutrophils and some eosinophils, but not basophils. Monocytes, lymphocytes, and erythrocytes were negative for CMRF-7 but neuraminidase treatment revealed "cryptic" sites on monocytes and some lymphoid cells. The antibody CMRF-7 reacted with the majority of acute myeloid leukemia blasts in the FAB categories M2-M5 but less frequently with M1 blasts and was positive with only 5/43 acute lymphoid leukemias. Immunoperoxidase staining of other normal human tissues indicates that this determinant is found on a range of epithelial cells in skin, the gastrointestinal tract and the genitourinary system. In addition some parts of the central nervous tissue and some endocrine organs stained with these antibodies.