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Biomedical subjects

A Bruno

Publications and source records attributed to A Bruno.

252 records · Page 14Linked to original sources

Cryptosporidium parvum life cycle in suckling mice: a Nomarski interference-contrast study of a human-derived strain.

Cryptosporidiosis has emerged as one of the life-threatening opportunistic enteric infections in HIV-infected persons. To date, Cryptosporidium parvum is known to infect man via person-to-person or zoonotic transmission. We studied the sequential stages of the life cycle of C. parvum by Normarski interference-contrast microscopy in fresh gut specimens of newborn mice, infected with a strain derived from an AIDS patient with cryptosporidial diarrheal enteritis. Many 4- to 5-day-old suckling BALB/C mice were orally inoculated with 1 x 10(6) oocysts, obtained by acid flocculation of the patient's stools. The animals were sacrificed from 4 to 96 h post-infection and the ileum was examined microscopically. All stages of the asexual life cycle of C. parvum, from excysted sporozoites in the intestinal lumen through the development of type II mature meronts, 12- to 72-h post-infection, were documented by extemporaneous microscopic evaluation of fresh gut samples. The sexual cycle, characterized by the appearance of micro- and macrogametocytes, followed by a zygote developing into a sporulated oocyst, was documented as early 48-h post-infection. Our Nomarski interference-contrast observations on the life cycle of C. parvum yielded data comparable with those originally published by Current and Reese, and confirm the results of previous electron microscopic studies performed by several other authors.

Acquired Immunodeficiency Syndrome↗

Albumin excretion rate is not increased in atherosclerotic patients with peripheral vascular disease.

In type I diabetic patients, microalbuminuria is considered predictive of nephropathy and has been found associated with an increased mobility and mortality for atherosclerosis. An association between microalbuminuria and atherosclerosis has been reported in non diabetic atherosclerotic patients with hypertension. The aim of this study is to evaluate whether albumin excretion rate (AER) is increased in a selected group of normotensive patients with documented peripheral atherosclerotic disease. We measured the AER on overnight urine collections in: 20 normotensive, non diabetic, atherosclerotic patients and in 14 healthy volunteers, matched for sex, age, body mass index. All subjects had normal renal function and negative family history of hypertension and diabetes. The AER values were 2.46 +/- 0.52 micrograms/min in controls, 3.25 +/- 0.69 micrograms/min in atherosclerotic patients, and the difference was not statistically significant. No subject (patient or control) was microalbuminuric. These results suggest that AER is not a marker of widespread vascular damage in normotensive atherosclerotic patients with normal glucose tolerance.

Albuminuria↗

Total body bone scan in the evaluation of tumor response to preoperative chemotherapy in the treatment of osteosarcoma.

With the introduction of preoperative (neoadjuvant) chemotherapy in the treatment of osteosarcoma, an early preoperative evaluation of the effectiveness of chemotherapy is essential, so that treatment may be modified in cases which are not responsive, and so that the surgical margin may be planned. The authors evaluate the accuracy of total body bone scan with Tc99m MDP in determining response to chemotherapy in 43 patients affected with osteosarcoma of the limbs, and preoperatively submitted to two cycles of chemotherapy with MTX i.v. and CDP i.a. All of the cases were submitted to a double bone scan examination, before and after preoperative chemotherapy. A bone scan evaluation using a qualitative method was compared to the percentage of necrosis observed in the tumorous tissue by histological examination carried out after surgery. In 58% of the cases the two values corresponded perfectly, in 28% of the cases bone scan evaluation overestimated response, and in 14% it underestimated it. In order to obtain quantitative preoperative data on response to chemotherapy in osteosarcoma, orientation towards the use of more sophisticated bone scan methods seems to be necessary, with computerized analysis of captation by dynamic measurement after infusion of Tc99m MDP or by radiocompounds with intracellular fixation such as Ga 67.

Adolescent↗

[Operations for limb salvage in vascular surgery].

Direct revascularization which involve the femoro-popliteo-tibial district is called "limbs salvage" surgery. Such operations are performed in the arteriopathic patient in order to avoid ulcers and distal necrosis, whose natural evolution, without an adequate treatment, leads to amputation. One of the distal by-pass techniques is obtained by using in situ saphenous vein. The Authors report their experience with 281 patients who underwent direct revascularization surgery (by-pass), discussing technique and results.

Aged↗

Preprandial and postprandial variations of insulin sensitivity in different times of the day assessed by the artificial pancreas in type I diabetics.

The aim of this study is to see whether changes in insulin need and in sensitivity to exogenous insulin occur in insulin-dependent diabetics receiving 3 daily non-isocaloric meals (at 0630, 1200 and 1730). In 9 type I diabetics submitted to the artificial pancreas control the insulin administered/dietary carbohydrates index (I/C) after breakfast (2.4 +/- 0.5) was significantly higher than after lunch (0.8 +/- 0.1) and after supper (0.84 +/- 0.1) (p less than 0.01). A trend to the reduced insulin sensitivity in the morning was also observed in fasting periods, when it was calculated as the ratio between blood glucose and insulin administered (BG/I): differences of BG/I however were not significant. It was concluded that diurnal variations of insulin sensitivity do occur in type I diabetic subjects, with an increment of insulin requirement in the morning.

Blood Glucose↗

Triple immunofluorescence evaluation of CD15, CD34 and class II expression by flow cytometry in normal and leukemic bone marrows.

BACKGROUND: The CD15/CD34 phenotype has been reported as aberrant and exploited for monitoring minimal residual disease in acute myeloid leukemia (AML) patients. Moreover, CD15/CD34 has been described as a rare phenotype in normal bone marrow (NBM) (< 0.10%). We used a triple immunofluorescence assay to investigate the expression of CD15, CD34 and class II antigens in normal (NMB) and leukemic (LBM) bone marrows. METHODS: A FACScan for quantitative fluorescence and the PAINT-A-GATE program for multiparametric analysis were utilized. Fifteen normal bone marrow and fifteen leukemic bone marrow samples were studied with a triple immunofluorescence assay. A FACSorter was used for sorting. RESULTS: Eleven out of 15 normal marrows contained less than 0.67% (range 0.01-0.66) cells which coexpressed CD15, CD34 and class II antigens. Three normal marrows contained more than 0.67% but less than 1.84% (range 1.05-1.83) triple stained cells. The entire group of leukemic marrows coexpressed triple stained cells with a frequency higher than 1% (range 1.1-48.6); furthermore, 10 samples contained the same population at frequencies higher than 10%. The difference between normal and leukemic marrows was statistically significant (p = < 0.001). Triple positive cells (TPc) from NBM were sorted for morphology, which proved to be consistent with myeloid progenitor features (early myeloblasts). This confirms that CD15+ CD34+ Class II+ precursors are commonly expressed in NMB, although at low frequency. Interestingly, 12 (80%) AMLs out of 15 were diagnosed as M1 (5) or M2 (7), while the remaining were M4 (2) and M5a (1). Additionally, all M2 cases were positive at percentages higher than 10%. Apparently CD15, CD34, class II expression correlates mainly with granulocyte differentiation. Two complete remission (CR) LBM, positive at onset for the triple combination, were regularly monitored. In one case the TPc percentage always remained near the normal values found in NBM (0.72%), and this patient is still in CR. In the other, overt relapse was preceded by a progressive increase in the TPc percentage. CONCLUSIONS: Although the presence in NBM of CD15+ CD34+ and class II+ precursors hinders minimal residual disease detection, we conclude that this unusual combination may distinguish a leukemic population and may allow monitoring of "early relapse".

Acute Disease↗

Diagnosis of acute myeloid leukemia and system Coulter VCS.

BACKGROUND: The aim of this study was to evaluate the possible contribution VCS could make in a hematological laboratory for the diagnosis of acute myeloid leukemia (AML). MATERIALS AND METHODS: Peripheral blood samples from 42 AML patients and 58 normal donors were analyzed by flow cytometry with the VCS. Normal and leukemic peripheral blood samples were tested to establish a correlation between VCS data and the reference manual method. We evaluated the sensitivity threshold of the VCS for blast cell detection in progressively diluted samples. We looked at a correlation between different scatterplots and flags and the FAB classification of acute myeloid leukemia in order to identify a characteristic VCS image for each subtype. Thirty-four bone marrow samples (18 normal donors and 16 leukemic patients) were analyzed by the VCS system to demonstrate a characteristic scattergram distribution. Further, we tried to compare scatterplots to the flags of leukemic bone marrow samples and, finally, we compared VCS scatterplots with aberrant antigen expression in AML cases. RESULTS AND CONCLUSIONS: Overall VCS specificity was 93.1% (54/58) in peripheral blood samples; sensitivity was 100% (42/42) and VCS efficiency was 96%. In AML the characteristic X6 flag was observed in 95.23% of the cases (40/42). In peripheral samples discrimination was made between AML M1 with agranular blasts > 50% of the non erythroid cells (NEC), M4, M5 on the one hand, and AML M1 with granular blasts > 50% of NEC, M2, M3 on the other: the X5 flag was often present in the second group because of the different localization of the cells (p = 0.001). In all normal bone marrow samples we observed granuloblasts in different maturation stages in the neutrophil region of the DF1 VCS scatterplot corresponding to the X5X6 flags or, rarely, to the X5X6X1, because of the presence of immature erythroid cells. This association X5X6 was never observed alone in patients affected by AML. In our study, it was difficult to identify peculiar scatterplots and alarms for each FAB class of AML. Nevertheless, we observed that in all M4 and M5 FAB cases the blastic cells both in the peripheral blood and in the bone marrow samples were located in the monocyte region, with the frequent presence of the X3 flag often associated with the X6 flag. Eight out of the 16 AML bone marrow samples (1 FAB M0, 1 M2, 1 M3, 2 M4, 3 M5) showed the X2 flag and partial localization of blasts in the lymphoid region. In all these cases the presence of some small blastic cells with agranular cytoplasm was confirmed by morphological observation and cytochemical stainings.

Acute Disease↗