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Biomedical subjects

A Colombo

Publications and source records attributed to A Colombo.

At least 145 records · Page 8Linked to original sources
PubMed1992

Coronary angioplasty of chronic occlusions: factors predictive of procedural success.

In a retrospective study of 365 chronic total occlusions that were submitted for angioplasty, we studied the influence of 27 clinical, morphologic, and procedural variables as possible predictors of successful outcomes. Success rate was shown to be significantly influenced by the following variables: operator experience (41% in early patients, first 6 months; 73% in late patients, last 6 months of entire series; p less than 0.001), duration of occlusion (less than or equal to 1 month, 89%; 1 to 3 months 87%; greater than or equal to 3 months 45%; unknown 60%; p less than 0.001), morphology of occlusion (tapered, 83%; abrupt, 51%), length of occlusion (less than or equal to 15 mm, 71%; greater than 15 mm, 60%; p less than 0.001), and bridging collaterals (present, 29%; absent, 67%; p less than 0.001). None of the other clinical, angiographic, or procedural variables correlated with the success rate of coronary angioplasty. The calculated probability for an experienced operator (greater than 100 occlusions attempted) to successfully open an occlusion with favorable morphology (less than or equal to 1 month old, short, tapered, without bridging collaterals) is 99%. An attempt by the same operator to open an occlusion with unfavorable structure (greater than or equal to 3 months old, long, untapered) has only 47% probability of success. The probability increases to 84% when the occlusion is tapered. We concluded that in addition to the duration and the length of occlusion, tapered morphology, bridging collaterals, and operator experience can predict successful angioplasty in chronic total coronary occlusion.

Aged↗
PubMed1992

Mathematical definition of the curve of Spee in permanent healthy dentitions in man.

The intrinsic morphology of the mandibular curve of Spee (i.e. independent from reference planes) was studied in 50 men and 45 women with sound dentitions. Left and right curves were reconstructed by a second-order quadratic interpolation of buccal cusp tips. Gender differences were found in both sides, while side differences were found only in the male sample. Male and female curves had similar concavities, but the position of the interpolating second-order quadratic curve relative to the dental arch was significantly different. The right and left male sides showed different concavities, the right-hand side being flatter than the left. Male curves appeared larger than female ones, and the left-hand side was significantly larger than the right regardless of gender. The reported second-order quadratic curves could be used as reference for prosthetic and orthodontic reconstructions.

Adult↗
PubMed1992

Percutaneous transluminal coronary angioplasty in patients aged 70 years and older: immediate and long-term results.

We analyzed all coronary angioplasty procedures performed in patients aged greater than 70 yr since 1987. There were a total of 92 patients with a mean age of 74 +/- 4 yr (range 70-82). The clinical diagnosis was unstable angina in 79%. Single-vessel disease was present in 41%, double-vessel in 29% and triple-vessel in 30% of patients. A left ventricular ejection fraction of less than 40% was present in 18 patients. Angioplasty was attempted on one vessel in 52 patients (56%), on two vessels in 29 patients (32%) and in three vessels in 10 patients (11%). Angiographic success was achieved in 96% of stenoses and in 53% of chronic total occlusions attempted. Complete revascularization was achieved in 56% of patients. Complications included three patients (3.2%) who underwent emergency coronary artery bypass grafting, 1 patient (1.1%) who sustained a myocardial infarction and 5 patients (5.4%) who died. During hospitalization, which averaged 3 +/- 2 days, 1 patients sustained reversible renal failure and 5 patients required blood transfusion for a large groin hematoma. Clinical success at discharge was 83%. At a mean follow-up of 13 months (range 3-45 months), symptomatic improvement was observed in 59 of the 76 patients who had achieved clinical success, with 42 of these patients (55%) being asymptomatic. The following clinical events occurred: myocardial infarction in 1 patient, new percutaneous transluminal coronary angioplasty in 9 and 3 patients died of cardiac reasons.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Comparative studies on the effects of doxorubicin and differentiation inducing agents on B16 melanoma cells.

The differentiation-inducing activity of doxorubicin on B16 melanoma cells grown in vitro was compared with that of other known differentiation inducers, such as theophylline, retinoic acid, and melanocyte-stimulating hormone (MSH). At drug concentrations resulting in cytostatic effects, doxorubicin and theophylline induced morphological changes (dendritic-like structures with a terminal melanin granule) with an enhancement of total melanin content and tyrosinase activity. Retinoic acid did not alter melanin content and cell morphology, although it affected cell growth. MSH enhanced total melanin content and tyrosinase activity, with no significant morphological changes. Flow cytometric analysis showed that MSH led to an accumulation of cells in G1 phase whereas doxorubicin induced an accumulation of cells in G2 + M. Studies on DNA content in doxorubicin-treated cells, selected on the basis of a morphologically differentiated pattern, showed a clustering of these cells in G2 + M, probably due to a cytokinesis block. Thus doxorubicin can induce cell differentiation comparable with other differentiation inducers.

Animals↗
PubMed1992

A model-based study of learning and memory following transient global amnesia attacks.

Verbal learning and forgetting were studied in patients one month after an episode of Transient Global Amnesia and in normal control subjects by means of a two-stage stochastic model, which allows independent measurements of encoding, storage and forgetting. We preliminarily ascertained both the necessity and the sufficiency of the model to account for several performance scores of the two experimental groups, and then compared the learning and forgetting functions between groups. In spite of the analytical power of the statistical method adopted. Transient Global Amnesia was not found to entail persistent impairment of encoding and storage, as well as of retaining memory traces and retrieval algorhythm.

Cerebral Cortex↗
PubMed1992

A comparison of secretory antibodies in breast-fed and formula-fed infants over the first six months of life.

In the present study salivary IgA, anti-Escherichia coli, anti-beta-lactoglobulin and anti-poliovirus type 1 IgA and IgM in serum and saliva were evaluated longitudinally in 13 breast-fed and 14 formula-fed infants over the first six months of life. Salivary IgA was quantified by electroimmunodiffusion; specific IgA and IgM antibodies were determined in serum and saliva by ELISA. Salivary IgA was significantly lower at age one month in breast-fed compared with formula-fed infants but in breast-fed infants salivary IgA increased with age and was significantly higher at six months than at one month. In both groups of infants, at the age of six months, salivary IgA levels were significantly lower than in adult controls. No significant differences in secretory anti-E. coli were observed between the two groups of infants. Salivary anti-poliovirus IgA and IgM antibodies increased transiently only to disappear in most babies at age six months, while anti-beta lactoglobulin IgA and IgM, present in saliva at all ages, showed a wide scatter. No important differences in specific serum IgA or IgM antibodies were observed either between the groups or at different times within the groups.

Age Factors↗
PubMed1992

Veralipride for hot flushes during gonadotropin-releasing hormone agonist treatment.

Hot flushes are the commonest symptom induced by gonadotropin-releasing hormone agonists (GnRHa). We performed an open observational trial to evaluate the efficacy of veralipride, an antidopaminergic drug, in reducing hot flushes in 25 premenopausal women treated with a GnRHa for endometriosis (8 subjects) or menorrhagia (17 subjects). The patients received goserelin depot for 6 months and veralipride was added for the third month. Hot flushes, severe in all women at 2 months, improved in both frequency and intensity in 92% of the subjects during veralipride administration. The benefit obtained persisted until the end of the GnRHa treatment.

Adult↗
PubMed1992

Results of coronary angioplasty in patients aged 75 years and older.

We studied a group of 47 patients greater than or equal to 75 years old. The mean age was 77 +/- 1.5 years and there were 28 (60 percent) male patients. Multivessel disease was present in 72 percent. Angioplasty was successful in 93 percent of 90 stenoses and in 30 percent of ten total occlusions. Single vessel angioplasty was done in 53 percent of patients, double vessel in 28 percent and triple vessel in 19 percent. Incomplete or absent revascularization was present in 47 percent and 9 percent, respectively. Primary clinical success was accomplished in all patients with single vessel disease; in 85 percent of patients with double vessel disease, and in only 52 percent of patients with triple vessel disease. Complications were highest in patients with triple vessel disease: 14 percent mortality and 5 percent emergency CABG. The follow-up at one year showed 91 percent survival. The PTCA is a valid alternative method of revascularization in elderly patients with single and double vessel disease. The results in triple vessel disease are less encouraging.

Age Factors↗
PubMed1992

Laparoscopic aspiration of ovarian endometriomas. Effect with postoperative gonadotropin releasing hormone agonist treatment.

In the period 1988-1990 this prospective study of 33 women with moderate or severe endometriosis who underwent laparoscopy for infertility and/or chronic pelvic pain, was conducted to evaluate the efficacy of aspirating endometriotic cysts followed by administration of a gonadotropin releasing hormone (GnRH) agonist in reducing the size of ovarian endometriomas. The cysts (mean diameter, 4.5 cm; range, 2-7; unilateral, 21 cases; bilateral, 12 cases) were punctured, aspirated, washed and emptied completely. After laparoscopy, 15 subjects received goserelin administered as a 28-day subcutaneous depot for three months, whereas 18 patients undergoing simple observation constituted internal controls. Ultrasound scans were performed before and at one, three and six months after laparoscopy. One case and three controls requested surgery between the four- and five-month follow-up scans and did not complete the study. All the other women had recurrent cysts at the six-month scan. There were no significant differences in mean endometrioma diameter between the two groups at any observation time nor between prelaparoscopic and six-month ultrasound examinations within each treatment group. We conclude that aspiration and washing of endometriotic cysts, combined with postoperative administration of GnRH agonists or not, is ineffective.

Adult↗
PubMed1992

[Angioplasty in total occlusion of the coronary arteries: the importance of the angiographic variables].

Total coronary occlusions can be treated by coronary angioplasty with a lower success rate when compared to the angioplasty success rate of stenoses. To evaluate factors associated with successful re-opening of total coronary occlusion we evaluated 128 occlusions attempted in 120 patients. We analyzed clinical and angiographic variables. Successful re-opening was obtained in 65% of total occlusions attempted; 1 patient (0.8%) had to undergo emergency coronary artery bypass surgery. Only the morphological characteristics of the occlusions were predictive of success. When total occlusions had a tapered morphology, success was achieved in 87% of the attempts versus 50% of success without tapered morphology (p < 0.001). The success, when the occlusion was associated with the presence of bridging collaterals, was very low (present: 30% success; absent: 71% success, p < 0.005). Success for occlusions longer than 1.5 cm was lower when compared to shorter occlusions (61% vs 78%; p < 0.005). The type of occlusion (absolute, functional), the presence of a branch originating at the level of the occlusion, the duration of the occlusion, the artery and its segment were not predictive of success. Multivariate analysis showed that tapered morphology was the only variable associated with successful re-opening of a total occlusion (87% probability of success when present). We conclude that it is possible to re-open a total coronary occlusion with low complication rate and high primary success rate when careful care is applied with particular attention paid to the morphology of the occlusion.

Adult↗
PubMed1992

The molecular architecture of an insect midgut brush border cytoskeleton.

The cytoskeletal apparatus of the vertebrate intestinal brush border (BB) has served as a model system for the actin-based cytoskeleton of nonmuscle cells. In this study, we examine the structural organization and molecular architecture of the BB cytoskeleton expressed in the midgut of lepidopteran larvae, Manduca sexta. Electron microscopy of the midgut of the 5th instar larvae revealed enterocytes with an apical BB surface comparable to that in the vertebrate intestine, with both microvillar (MV) and terminal web (TW) domains, the latter defined by a zone of organelle exclusion directly beneath the MV. As reported previously for the larval dragon fly, the MV contain a bundle of actin filaments, as determined by staining with rhodamine phalloidin (Kukulies, J., et al., Protoplasma 121, 157-162 (1984)) and heavy meromyosin decoration (Komnick, H., J. Kukulies, Zoomorphology 107, 241-253 (1987)). Two-dimensional gel analysis revealed the presence of multiple isoelectric variants of actin with the major isoform corresponding to the non-muscle actin isoform II, expressed in Drosophila. Like the vertebrate BB, the Manduca BB can be isolated intact from enterocytes by mechanical shear. Immunochemical analysis of isolated BB fractions or whole homogenates of midgut revealed proteins of appropriate molecular weight immunoreactive with antibodies to the MV core proteins: BB myosin I, villin and fimbrin, and the TW components: spectrin, myosin II and tropomyosin. Immunocytochemical localization of a subset of these proteins at the light microscopic (spectrin) and electron microscopic (actin, villin, spectrin, myosin II, and tropomyosin) level reveals that the molecular architecture of the Manduca BB cytoskeleton is homologous to that found in vertebrates.

Animals↗
PubMed1992

[A new therapeutic approach in hepatic hydrothorax].

Hepatic hydrothorax is a complication of hepatic cirrhosis which frequently conditions respiratory insufficiency. Traditional therapy is almost always inefficacious. The paper reports four cases which were successfully treated using pleurodesis with sterile talc. Treatment was simple with no major complications. At the 6-month check-up no cases of recurrent pleural effusion were observed.

Adult↗
PubMed1992

["Kissing balloon" of the protected common trunk of the left coronary artery: description of a successfully treated case].

The authors describe a case of coronary angioplasty on a distal Left Main coronary lesion. The left coronary tree was protected by the left internal mammary connected to left anterior descending artery. The procedure was performed using the "kissing balloon" technique, with a single guiding catheter. Immediate angiographic result and one-year follow-up have been excellent.

Angioplasty, Balloon, Coronary↗
PubMed1991

Identification of spectrin and calmodulin in rabbit spermiogenesis and spermatozoa.

Actin was localized in the four subacrosomal bulges (Camatini et al., Eur. J. Cell Biol. 45:276-281, 1987), which characterize the sperm head of rabbit spermatozoa (Phillips, J. Ultrastruct. Res. 38:591-604, 1972), and in the postacrosomal region (Welch and O'Rand, Dev. Biol. 109:411-417, 1985; Camatini et al., Eur. J. Cell Biol. 45:276-281, 1987). Specific antibodies and indirect immunogold labelling on testis Lowicryl K4M sections and spermatozoa cryosections were used to study the distribution of calmodulin and a spectrin-like protein. This protein was also present close to the shaping membranes of the head. The results presented suggest a membrane-cytoskeletal role of actin, spectrin, and calmodulin.

Animals↗
PubMed1991

A computer filing system for drug use in a pregnancy consultation service.

A computerized database for documenting drug use in pregnancy was set up on a personal computer. Summaries of the information available from the literature on more than 700 drugs taken during pregnancy have already been entered and are currently in use. This reliable, cheap, handy, and personal system (the first available on the topic) may be a potentially useful instrument not only for drug consultation services, but for individual physicians, too.

Databases, Factual↗
PubMed1991

Deficient antiendometrium lymphocyte-mediated cytotoxicity in patients with endometriosis.

OBJECTIVE: To study the possible role of the immune system in the pathogenesis of endometriosis. DESIGN: A cytotoxicity assay by 51Cr release was performed to determine the lymphocyte cytotoxic response toward endometrial targets and an erytroleukemic cell line (K562). SETTING: The assays were performed in an academic research environment. PATIENTS, PARTICIPANTS: Twenty-five control women and 25 patients with endometriosis were selected on the basis of laparoscopic examination. INTERVENTIONS: The lymphocyte cytotoxic activity was evaluated separately on endometrial stromal and epithelial cells after 4 hours' incubation. MAIN OUTCOME MEASURE: The study was designed to determine, in controls and endometriosis patients, the lymphocyte-mediated cytotoxicity toward stromal and epithelial cells of endometrium. RESULTS: The lymphocyte response in the presence of stromal cell antigens was significantly lower (P less than 0.02) in disease-affected women when compared with that obtained in controls (2.89 +/- 0.87 and 7.64 +/- 1.66, respectively). In contrast, when the same assay was performed on K562 cells, no difference was observed between endometriosis patients and controls. CONCLUSIONS: These data suggest that an altered immune recognition might be one of the pathogenic mechanisms of endometriosis. Moreover, they indicate that this is not a general phenomenon but is specific for the endometrial target.

Adult↗
PubMed1991

The aphasic isolate. A clinical-CT scan study of a particularly severe subgroup of global aphasics.

This paper outlines the clinical and CT scan features of a subtype of global aphasia, characterized by an extreme loss of communicative abilities, verbal as well as nonverbal. Three to four weeks after a left hemisphere stroke, 17 patients were completely unable to communicate with people addressing them. Though there were differences in their willingness to interact with the environment, they were characterized by complete loss of speech output and by inaccessibility to any kind of message, whether given verbally or through gestures. Patients who survived were reassessed 6 and 12 mos later and half of them were still found in a state of complete communicative isolation. The remainder had somewhat improved, but remained globally aphasic. The attempt to find a CT scan basis for this picture was disappointing. Only 35% of patients had a lesional pattern in agreement with the traditional view that ascribes global aphasia to the involvement of Broca's and Wernicke's areas. The location of lesion in the other cases spanned from anterior cortical damage, to posterior cortical damage, to deep nuclei damage and none of the lesions that have been proposed to account for subcortical global aphasia was consistently observed.

Aged↗