Erythroid failure in Diamond-Blackfan anemia is characterized by apoptosis

Programmed cell death, also known as apoptosis, is frequently initiated when cells are deprived of specific trophic factors. To investigate if accelerated apoptosis contributes to the pathogenesis of Diamond- Blackfan anemia (DBA), a rare pure red blood cell aplasia of childhood, we studied the effect of erythropoietin (epo) deprivation on erythroid progenitors and precursors from the bone marrow of DBA patients as compared with hematologically normal controls. Apoptosis in response to epo deprivation was evaluated by enumeration of colony-forming unit- erythroid (CFU-E)- and burst-forming unit-erythroid (BFU-E)-derived colonies in plasma clot semisolid culture and by the identification of typical DNA oligosomes by gel electrophoresis from marrow mononuclear cells in liquid culture. In all DBA patients there was a marked decrease in CFU-E- and BFU-E-derived colony formation compared with normal controls at comparable time points of epo deprivation, with a complete loss of CFU-E-derived colonies in semisolid culture by 9 hours of epo deprivation versus 48 hours in controls. The BFU-E-derived colony response to epo deprivation displayed a similar pattern of decrement. Apoptotic changes assessed by the presence of characteristic DNA fragmentation began in the absence of epo deprivation and were readily detected within 3 hours of epo deprivation in DBA cultures versus 9 hours in controls. We conclude that DBA is characterized by accelerated apoptosis as measured by the loss of erythroid progenitor clonogenicity and increased progenitor and precursor DNA fragmentation leading to the formation of characteristic oligosomes, consistent with an intrinsic erythroid-progenitor defect in which increased sensitivity to epo deprivation results in erythroid failure.     

A selective cyclooxygenase 2 inhibitor suppresses the growth of H-ras-transformed rat intestinal epithelial cells

BACKGROUND & AIMS: Constitutive expression of cyclooxygenase 2 (COX-2) has been found in 85% of colorectal cancers. Ras mutations are found in 50% of colorectal adenocarcinomas. The aim of this study was to determine the role of COX-2 in ras-induced transformation in rat intestinal epithelial (RIE) cells. METHODS: Cell growth was determined by cell counts. The expression of COX-2 was examined by Northern and Western analyses. For tumorigenicity assays, cells were inoculated into dorsal subcutaneous tissue of athymic nude mice. DNA-fragmentation assays were performed to detect apoptosis. RESULTS: The expression of COX-2 was increased in RIE-Ras cells at both messenger RNA (9-fold) and protein (12-fold) levels. Prostaglandin I2 levels were elevated 2.15-fold in RIE-Ras cells. Serum deprivation further increased COX-2 expression 3.8-fold in RIE-Ras cells. Treatment with a selective COX-2 antagonist (SC58125) inhibited the growth of RIE-Ras cells through inhibition of cell proliferation and by induction of apoptosis. SC-58125 treatment reduced the colony formation in Matrigel by 83.0%. Intraperitoneal administration of SC-58125 suppressed RIE-Ras tumor growth in nude mice by 60.3% in 4 weeks. SC-58125 treatment also induced apoptosis in RIE-Ras cells as indicated by increased DNA fragmentation. CONCLUSIONS: Overexpression of COX-2 may contribute to tumorigenicity of ras-transformed intestinal epithelial cells. Selective inhibition of COX-2 activity inhibits growth of ras-transformed intestinal epithelial cells and induces apoptosis. (Gastroenterology 1997 Dec;113(6):1883-91)     

Juvenile amyopathic dermatomyositis

We report a 15-year-old girl with a 10-year-old history of typical skin features of dermatomyositis (DM) without evidence of muscle involvement. Amyopathic dermatomyositis(ADM) is defined by the presence of biopsy confirmed classic cutaneous findings of dermatomyositis in the absence of any clinical or laboratory signs of muscle disease for at least 2 years after onset of skin pathology. To exclude muscle involvement muscle enzymes should be normal; moreover additional use of magnetic resonance imaging and muscle ultrasound is currently being proposed. It is as yet undetermined. whether early aggressive immunosuppressive treatment of ADM might prevent the development of myositis at a later date or influence the course of the skin disease. In a paediatric patient with ADM we advocate a more expectant attitude with careful and regular monitoring for possible development of muscle disease.     

Association of interstitial nephritis with tubule cell injury and proliferation in NZB/NZW mice.

A technique is described which shows how to obtain a suspension of only progressively motile spermatozoa, from semen, by active penetration into an overlying buffer layer. About 60% of the number of motile spermatozoa in the original semen sample can be obtained as an output in the removed buffer layer. With this method many more semen samples, in particular those with less than 70% motile spermatozoa, can be used than otherwise would have been possible. Moreover, with such a suspension of only motile spermatozoa the sensitivity of the micro-immobilization test is substantially improved, due to the absence of non-specific clumping, the minimization of specific tail-to-tail agglutination and an optimal end-point reading because of the absence of background immotility. As the complement source, a 1:8 dilution of rabbit or guinea-pig serum in human AB serum was found to be most suitable. The 1 microliter sperm suspension is initially mixed with 2 microliter of serum and incubated for 30 min, and then a further 2 microliter volume of complement is added, which is incubated for 2 hr with the serum-sperm mixture, and the test is read under an inverted microscope.     

Treatment of Bech?et's syndrome with transfer factor

Six patients with Beh?et's syndrome were treated with transfer factor (TF) from randomly selected donors. Mucocutaneous symptoms and signs were predominant at the time that TF injections were started. Three patients showed great improvement, one moderate improvement, and one was unresponsive to multiple injections of TF from different donors. One case was uninterpretable because of concomitant administration of high doses of prednisone and chlorambucil and brief treatment with TF. These results indicate that TF therapy may be beneficial in some patients with Beh?et's syndrome and that a trial of TF is warranted at least in the absence of severe ocular or neurologic manifestations.     

Interstitial hyperthermia in combination with brachytherapy

Flexible coaxial cables were modified to serve as microwave antennas operating at a frequency of 915 MHz. These antennas were inserted into nylon afterloading tubes that had been implanted in tumors using conventional interstitial implantation techniques for iridium-192 seed brachytherapy. The tumor volume was heated to 42-45 degrees C within 15 minutes and heating was continued for a total of 1 hour per treatment. Immediately following a conventional brachytherapy dose and removal of the iridium seeds the tumors were heated again in a second treatment. This interstitial technique for delivering local hyperthermia should be compatible with most brachytherapy methods. The technique has proved so far to be practical and without complications. Temperature distributions obtained in tissue phantoms and a patient are described.     

Tobacco smoking: a comparison between alcohol and drug abuse inpatients

This study compared the tobacco smoking of alcohol and drug abuse patients. The subjects were male inpatients (67 alcohol, 60 drug, and 13 mixed alcohol and drug abusers) of a Veterans Administration substance abuse program who had completed the Tolerance Questionnaire (Fagerstrom, 1978) and the Michigan Alcohol Screening Test (Skinner, 1979) as part of routine intake assessment procedures. As expected, an extremely high percentage (89.6%) of the alcohol abusers reported smoking cigarettes. Interestingly, an equally high prevalence of smoking was noted among the drug (90.0%) and mixed substance abuse (100%) groups. Comparisons conducted between abuse groups indicated that the alcohol abusers smoked significantly more cigarettes per day and had significantly higher Tolerance Questionnaire scores than the drug abusers, but did not differ from the mixed abuse group on any smoking variable. Additional comparisons of the total substance abuse population with a national sample of similarly aged males indicated that only the alcohol group smoked more cigarettes per day, but that all substance abuse groups smoked higher nicotine delivery cigarettes than the national sample.