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Biomedical subjects

M Colombi

Publications and source records attributed to M Colombi.

At least 73 records · Page 4Linked to original sources
PubMed1987

Acute gangrene of the scrotum and penis in four hematologic patients. The usefulness of hyperbaric oxygen therapy in one case.

We describe four cases of Fournier's gangrene complicating the postchemotherapy aplastic phase (polymorphonuclear cells [PMN] less than 500/microliter) in three patients with acute leukemia and one patient with non-Hodgkin's lymphoma. Blood and local cultures from two patients contained Pseudomonas aeruginosa, and local cultures from another patient grew both P. aeruginosa and Proteus rettgeri. Early recognition and aggressive antibiotic and surgical treatment with granulocyte recovery were fundamental factors in resolution of the gangrene in three of the four patients. Hyperbaric oxygen therapy, never reported in hematologic patients, was also very useful in one patient in whom the clinical course was particularly acute.

Adolescent↗
PubMed1987

Thromboembolic and other events following valve replacement in a pediatric population treated with antiplatelet agents.

To determine if anticoagulation therapy is necessary after valve replacement with the St. Jude Medical prosthesis in young subjects, 30 consecutive patients were studied. They ranged in age from 4 to 20 years, and each had undergone valve replacement some time between February, 1982, and June, 1984. There was 1 hospital death (3.3%; 70% confidence limits [CL] = 0.4% to 10.9%). The 29 hospital survivors were treated with aspirin and dipyridamole. All patients were followed up. There were 5 late deaths (17.2%; 70% CL = 9% to 27%), at a mean of 8 months postoperatively. Follow-up revealed that 7 thromboembolic events occurred in 7 of the hospital survivors (24.1%; 70% CL = 15% to 35%). Hemiparesis occurred in 1 patient, and documented valve thrombosis and death occurred in another. Transient sensorimotor deficits were found in the 5 other patients. Prosthetic valve endocarditis developed in 1 hospital survivor (3.5%; 70% CL = 0.4% to 11%) and resulted in late death. There were no reoperations in the hospital survivors. We conclude that the St. Jude Medical prosthesis is useful for valve replacement in the young because of its low profile, durability, and hemodynamic characteristics. However, we recommend that these patients receive full anticoagulation therapy.

Adolescent↗
PubMed1987

Plasma cyclic nucleotide levels in acute leukemia patients.

To verify the clinical usefulness of extracellular cyclic nucleotide determination as a tumor marker, plasma cyclic AMP (cAMP) and cyclic GMP (cGMP) levels were measured in 70 normal subjects and 173 acute leukemia patients studied in different stages of their disease. Mean plasma cAMP levels were similar in leukemic and normal subjects, although in 48 patients in the active stage of the disease, first diagnosis, or relapse, the cAMP values were below the normal range, and most of these patients failed to respond to chemotherapy. Plasma cGMP levels were markedly elevated in untreated patients, normalized in all patients who attained complete remission, and increased promptly to pretreatment values in patients who relapsed, suggesting that their determination may be useful to monitor the patients' response to treatment.

Acute Disease↗
PubMed1986

A family of fibronectin mRNAs in human normal and transformed cells.

Previously, two fibronectin mRNAs, generated by alternative splicing of the extra domain (ED) and type III connecting segments (IIICS) sequences, have been described in a human transformed cell line and in human liver, respectively. We now report on a family of fibronectin mRNAs identified by Northern blotting analysis in two normal human fibroblast strains (HEL 299 and Flow 7000) and five transformed cell lines (8387 and HT-1080, fibrosarcomas; G-361, melanoma; JEG-3, choriocarcinoma; and RD, rhabdomyosarcoma). Seven different fibronectin mRNA forms with electrophoretic mobilities ranging between 8.6 and 7.7 kb were identified. Each cell line contains three (HEL 299, Flow 7000 and 8387) or two (HT-1080, G-361, JEG-3 and RD) fibronectin mRNAs species with characteristic size. In all cell lines we detected one fibronectin mRNA form which lacks the ED sequence (ED- fibronectin mRNA) and one or two fibronectin mRNAs containing it (ED+ fibronectin mRNA). These data show that the presence of ED+ and ED- fibronectin mRNAs is a general feature of all cells tested. Moreover, the fibronectin mRNA pattern is characteristic of the cell type analyzed, suggesting the occurrence of specifically programmed splicing mechanisms in each cell line.

Cell Line↗
PubMed1986

Relationship between circulating plasminogen activators and tumor development in mice.

Plasminogen activators (PAs) present in the plasma of BALB/c mice and produced in vitro by murine tumor cell cultures (B77-3T3, SR-BALB, AA6) have been characterized using electrophoretic-zymographic techniques. BALB/c mouse plasma contains a main PA activity with an approximate molecular weight of 88,000 and pI 6.3, inhibited by anti-human tissue-type plasminogen activator (t-PA) serum, here defined as murine t-PA. On the contrary, all tumor cells tested release a PA activity with a molecular weight of 44,500 and pI 9.2 characteristic of urokinase-type activator (murine u-PA). The injection s.c. of the different tumorigenic cells into BALB/c mice leads to tumor development and to a rapid increase of t-PA from the first day following the injection. This early enhancement of t-PA activity is not detectable in mice given injections of lethally irradiated B77-3T3 cells. Moreover the development of the tumor in the animals is related to the appearance of increasing levels of u-PA in the blood. This activity is detectable in the plasma of treated mice almost 2 wk before detection of a tumor 1 mm in diameter. During tumor development, the molecular weight of the u-PA and t-PA forms present in the plasma does not change, while there is a decrease of the isoelectric point of the u-PA leading to the appearance of distinct PA activities with pI 7.6 and 8.9. Syngenic and allogenic lymphocytes, injected in BALB/c mice, do not induce any modification in the pattern of the plasma PA. The injection of highly metastatic cells, as opposed to nonmetastatic or low-metastatic cells, does not give rise to detectable levels of u-PA in the plasma of treated mice. These data suggest that the lack of plasma u-PA activity facilitates the formation of metastates, while the increase of this activity is important in tumor development and is independent of the metastatic potential of the injected cells.

Animals↗
PubMed1984

Selective PF4 release in vitro induced by heparin and related glycosaminoglycans (GAGs)--correlation with beta-TG release and platelet aggregation.

We studied human platelet aggregation and beta-TG/PF4 release induced by heparin and related GAGs in vitro both in normal PRP and in PRP after aspirin. In our experimental conditions, heparin and related GAGs always caused PF4 release in vitro from normal platelets, whether or not there was measurable platelet aggregation in the aggregometer. Significant beta-TG release was induced only by the mucosal heparin preparation (which also induced platelet aggregation in some citrated PRP). Therefore, while beta-TG release in vitro seems to correlate with platelet aggregating activity of heparin, the selective PF4 release, caused by heparin and related GAGs also in conditions in which neither platelet aggregation nor beta-TG are measurable, is probably associated with the high affinity of PF4 for heparin. The degree of affinity of GAGs for PF4 (heparin greater than DeS greater than HS) seems to correlate with PF4 release. Moreover, the significant reduction in PF4 release in vitro after aspirin suggests that GAGs-induced PF4 release is related to a cyclooxygenase-dependent activation process.

Adenosine Diphosphate↗
PubMed1984

Value of CT scanning in the diagnosis of CNS mycotic involvement: report of 3 cases.

Fungal infections of the CNS are becoming an increasingly serious problem in immunosuppressed patients. We describe three patients with malignant blood disease who in the course of systemic fungal infection presented cerebral involvement. The nature, site and extent of the cerebral involvement were defined by computed tomography (CT). Further, in one patient it was possible to follow the course of the lesion and assess the effectiveness of antimycotic therapy by CT because of its noninvasiveness and repeatability.

Adult↗
PubMed1984

Relationship between multiple forms of plasminogen activator in human breast tumors and plasma and the presence of metastases in lymph nodes.

Plasminogen activators (PAs), a family of proteases active in blood coagulation, may play an important role in cancer. Indeed, blood coagulation disorders, such as altered fibrinogen and fibrin metabolism and increased incidence of vascular thrombosis, are common in patients with advanced malignant disease. Different types of human tumors are known to contain high levels of PA. The isoelectric focusing patterns of the PAs present in tumors and plasma from patients with breast cancer were compared with those of purified human urokinase and melanoma tissue PA. The pattern of isoelectric molecular forms of PA active at pH 8 showed two groups of several bands: in plasma from tumor-bearing patients and controls, these groups were in the pl ranges of 6.6 to 6.8 and 8.0 to 8.5; in mammary adenocarcinoma tissue, the ranges were 6.8 to 7.9 and 9.0 to 9.4. These patterns were different from those obtained with purified markers; the latter were 5.8 to 9.4 and 5.9 to 7.6 for purified human urokinase and melanoma plasminogen tissue activator, respectively. PA activity in tumor-bearing patients was very high in malignant tissue and, on the contrary, very decreased in plasma; this latter decrease was correlated with the presence of metastases in the axillary lymph nodes. These results suggest that the high PA activity in the tumor tissue might participate in the destruction of the peritumoral tissue, thus allowing its invasion by tumor cells, whereas the low activity of PA in the plasma might increase plasma fibrin, reflecting thus an early disorder in blood coagulation which would enhance the formation of metastases.

Adenocarcinoma↗
PubMed1984

Unusual bone marrow hyperplasia in a case of thalassemia intermedia.

A case of beta thalassemia intermedia is described. Beside the typical hematologic picture and extramedullary erythropoiesis in the liver always present in such a clinical form, atypical masses due to foci of erythropoiesis were found at paravertebral, parasternal and subcostal sites. The size of these masses caused problems in differential diagnosis; they have been solved by computerized axial tomography.

Adult↗
PubMed1983

Studies on transformation markers and tumorigenicity in segregant clones from a human hybrid line.

Thirty segregant clones were back-selected in 8AG or 5BUdR media from a non-tumorigenic human intraspecific hybrid line (HeLa TK- X fibroblasts HPRT-) displaying a high plasminogen activator (PA) level, a disorganized fibronectin (FN) matrix and anchorage-independence. These clones exhibited a widely modulated expression of the above markers concomitantly with different degrees of chromosome loss. Out of six representative segregant clones tested in nude mice, two were found to re-express tumorigenicity. No significant correlation was observed between PA or FN levels and anchorage-independence, as well as between these markers and tumorigenicity.

Animals↗