Content and thrombin-induced release of acid hydrolases in gel-filtered platelets from patients with storage pool disease

The levels of four acid hydrolases, beta-N-acetyl glucosaminidase, beta- glucuronidase, beta-galactosidase, and acid phosphatase, and the extent of their release (release II) by thrombin was determined in platelets from nine normal subjects, nine patients with storage pool disease, and in normal platelets which had been exposed to aspirin. The levels of all four hydrolases were normal in patients with SPD. However, release of three of these hydrolases (acid phosphatase was an exception) by low concentrations of thrombin (0.015 and 0.04 U/ml) was decreased in the patients as a group, although considerable variation in the extent of release of each enzyme was noted. In contrast, aspirin failed to inhibit release II in normal platelets (except for a slight impairment in the release of beta-N-acetyl glucosaminidase), although release I (serotonin, ATP and ADP) was inhibited. All release defects could be overcome by using higher concentrations of thrombin (0.2 U/ml). The normal levels of acid hydrolases in the platelets of patients with SPD (who are deficient in the platelet dense granules) suggest that these enzymes are not normally stored in the dense granules, but rather in alpha-granules. The findings also support the conclusions of previous studies that the release reaction is impaired in SPD. This release defect appears to be different from that seen in normal platelets after exposure to aspirin.     

Marrow harvesting from normal donors

The experience at a single institution in harvesting marrow for allogeneic transplantation on 1,270 occasions from 1,160 normal donors is presented in detail, together with an analysis of all the donor complications. Four donors were less than 2 years old, and the youngest was 6 1/2 months. No special difficulties were encountered with these young donors. Hospitalization time was three days or less for 99% of the procedures. Six donors had life-threatening complications; three of a cardiopulmonary and two of an infectious nature, and one cerebrovascular embolic episode. Significant operative site morbidity, usually transient neuropathies, occurred in ten procedures. Ten percent of the donations were associated with transient postoperative fever of unknown origin. Increasing donor age was associated with a reduction of the cellularity of the marrow harvest. The use of stored autologous blood permitted the avoidance of blood bank transfusion in 81% of males, 69% of females, and 50% of children. It was concluded that the procedure was associated with a very low risk of complication, but that the involvement of normal donors in such an operation justifies stringent monitoring.     

Primary retroperitoneal myxoid/round cell liposarcoma is a nonexisting disease: an immunohistochemical and molecular biological analysis

Almost all primary retroperitoneal liposarcomas can be classified as well-/dedifferentiated liposarcoma. Rarely, however, primary retroperitoneal liposarcoma is classified as myxoid/round cell liposarcoma, based on the presence of myxoid areas and vascular crow's feet pattern, which has resulted in a debate on the classification of liposarcoma in the retroperitoneum. Genetically, myxoid/round cell liposarcoma and well-/dedifferentiated liposarcoma are different diseases. Myxoid/round cell liposarcoma is characterized by a translocation causing FUS-CHOP or EWSR1-CHOP fusion, whereas well-/dedifferentiated liposarcoma is characterized by an amplification of the 12q13-15 region, including MDM2 and CDK4 genes. As myxoid/round cell liposarcoma is highly radio- and chemosensitive, differentiation between subtypes is important to optimize treatment. We studied whether primary retroperitoneal liposarcomas diagnosed as myxoid/round cell liposarcoma represent molecularly true myxoid/round cell liposarcoma or are histopathological mimics and represent well-/dedifferentiated liposarcoma. Primary retroperitoneal myxoid/round cell liposarcoma (n=16) were compared to primary extremity myxoid/round cell liposarcoma (n=20). Histopathological and immunohistochemical features were studied. Amplification status of the 12q13-15 region was studied using a multiplex ligation-dependent probe amplification analysis, and FUS-CHOP or EWS-CHOP translocations were studied using RT-PCR. In primary retroperitoneal myxoid/round cell liposarcoma, MDM2 and CDK4 staining was both positive in 12 of 15 cases. In primary extremity myxoid/round cell liposarcoma, MDM2 was negative in 18/20 and CDK4 was negative in all cases. Multiplex ligation-dependent probe amplification showed the amplification of 12q13-15 region in 16/16 primary retroperitoneal myxoid/round cell liposarcomas and in 1/20 primary extremity myxoid/round cell liposarcomas. Translocation was present in all (18/18) primary extremity myxoid/round cell liposarcomas, but absent in all primary retroperitoneal myxoid/round cell liposarcomas. On the basis of immunohistochemical and molecular characteristics, apparent primary retroperitoneal myxoid/round cell liposarcoma can be recognized as well-/dedifferentiated liposarcoma with morphological features mimicking myxoid/round cell liposarcoma. In these cases, treatment should probably be specifically designed as for well-/dedifferentiated liposarcoma. Moreover, finding of myxoid/round cell liposarcoma translocations in a retroperitoneal localization is highly suggestive of metastasis and should prompt search for a primary localization outside the retroperitoneum.     

Analysis of the relationship between age and treatment response in migraine

In migraine, headache severity varies with age. As a consequence, the effectiveness of medication may also depend on a patient's age. The purpose of this study was to assess the combined effect of age and drug treatment on headache characteristics. Using data from clinical trials of sumatriptan in adolescents and adults, we show how the interaction between age and drug exposure can be parameterised as a covariate on a Markov model that describes the decline of headache severity over three clinically defined stages (no relief, relief and pain-free status). The model explains important clinical observations: (i) the rates at which the pain relief and pain-free status were attained were found to be inversely related to age; (ii) in placebo-treated patients, the mean transit time from 'no relief' to 'relief' is 3 h for young adolescents and increases to 6 h for patients aged ≥ 30 years; and (iii) sumatriptan reduces the transit time to 2 h, irrespective of age. These findings indicate that the therapeutic gain over placebo increases with age. Prospective studies of antimigraine drugs should take this relationship into account when extrapolating efficacy data from adults to adolescents.     

Lung lesions: correlation between viewing time and detection

The influence of viewing time on the detectability of subtle and obvious lung cancers was studied. Frontal chest radiographs of 40 patients with subtle cancers, 40 patients with obvious cancers, and 40 healthy control subjects were shown to four observers for four different viewing times (0.25 second, 1 second, 4 seconds, and unlimited time). Receiver operating characteristic analysis was used to compare the detectability of lesions. Performance was degraded as viewing time decreased. The true-positive fractions for subtle and obvious cancers were 30% and 70% at 0.25 second and 74% and 98% at unlimited viewing time, respectively, for a given false-positive fraction of 20%. Thus, even with unlimited viewing time, the false-negative fraction for subtle cancers was 26%. The difference in detectability between subtle and obvious lung cancers was exaggerated at 1.0 second compared with 4 seconds and unlimited viewing time. The following conclusions were reached: (a) a substantial proportion of subtle lung lesions are missed, even with unlimited viewing time; (b) a large proportion of obvious lung cancers are detected with flash viewing; (c) the detectability of lesions decreases considerably as viewing time becomes less than 4 seconds; and (d) differences in detectability are exaggerated by short viewing times.     

Renal failure in giant cell vasculitis

A 59-year-old white woman with temporal arteritis developed progressive renal failure. Renal biopsy results showed focal and segmental necrotizing glomerulonephritis; furthermore, giant cells were present in the destructed vessel walls. Immunosuppressive therapy did not prevent terminal renal failure. This case shows that renal involvement may be a feature of temporal arteritis.