A software tool to straighten curved chromosome images

A software tool for straightening curved chromosomes has been developed and integrated into the freely available image analysis application Image SXM (available via the Internet at http://reg.ssci.liv.ac.uk). This new tool straightens curvilinear objects in one simple step after minimal input from the user. The ends of a curvilinear chromosome are identified by the user using the mouse and a window is opened displaying the object as it would appear if it was straightened out. This image processing produces linear images of chromosomes with no loss of resolution or spatial calibration, making subsequent analysis significantly more straightforward.     

Histamine concentration of gastric mucosa in Helicobacter pylori positive and negative children.

The histamine concentration was determined by enzymatic isotopic method in biopsy specimens of oxyntic mucosa from 37 children. Nineteen of the 37 had Helicobacter pylori associated gastritis (9 with duodenal ulcer). The histamine concentration in the H pylori negative group was mean (SD) 54.1 (23.1) micrograms/g fresh weight, and that in the H pylori positive group was 26.3 (14.2) micrograms/g (p less than 0.01). There was also a significant difference between H pylori positive patients with duodenal ulcer (19.8 (6.3) micrograms/g) and those without ulcer (31.4 (17.9) micrograms/g) (p less than 0.05). These results suggest that H pylori positive patients, especially those with duodenal ulcer, have reduced 'stored' histamine, perhaps because of increased histamine liberation.     

Value of transesophageal echocardiography in the diagnosis of acute aortic dissection]

We describe our experience of six patients with clinical suspicion of acute aortic dissection (AAD) who were studied consecutively by transesophageal echocardiography (TEE) from April to July of 1991. All of them were previously submitted to transthoracic echocardiogram. The diagnosis was correctly established by TEE in five cases, confirmed by aortography and/or surgery (four cases), or by autopsy (one case). In one patient the diagnosis of AAD was excluded by TEE, and posteriorly by nuclear magnetic resonance. Four patients had a Stanford type A, and one patient a type B dissection. The site of entry was identified in three cases; the intimal entry tear of the type B dissection, not observed by TEE, was localized in the aortic arch by aortography. In three of the four type A dissection cases, a thrombus in the false lumen and an aortic regurgitation were found. No other noninvasive methods were used after the diagnosis of AAD by TEE. The surgical repair was successful in three cases, one of which, without previous necessity of aortography. In our experience, TEE increased extraordinarily the diagnosis efficacy of AAD, making possible an earlier therapeutic approach, and probably contributing to the improvement of the prognosis of this pathology.     

Fetal heart rate at 10 to 14 weeks and birthweight

In 6644 singleton pregnancies resulting in live births, the fetal heart rate was measured at 10 to 14 weeks of gestation (median 12). There was no significant association between fetal heart rate and birthweight. These findings demonstrate that if there is an association between fetal heart rate, birthweight and subsequent development of cardiovascular disease the responsible intrauterine insult and/or the adaptive fetal response are not present at 10 to 14 weeks of gestation.     

Persistent diarrhea associated with AIDS

Chronic diarrhea and wasting are very common manifestations of AIDS in adults in developing countries. Etiologic studies show that protozoa (including Cryptosporidium parvum, Isospora belli , and Enterocytozoon bieniusi ) and Mycobacterium avium-intracellulara are the most frequently identified pathogens. Limited data in children suggest that common enteric pathogens are equally as likely in HIV⁺ and HIV^- babies. Preliminary analysis of an ongoing longitudinal study of 469 babies born to mothers with known HIV serostatus in Kinshasa, Zaire, reveals progression of acute to persistent diarrhea is six times greater in HIV⁺ compared to HIV^- babies, and 3.5 times greater in HIV^- babies born of HIV⁺ mothers in comparison to HIV^- babies with HIV^- mothers. HIV⁺ babies were also at greater risk than HIV^- babies to have recurrent episodes of diarrhea (RR = 2.3). Fifty percent of the deaths were due to acute or persistent diarrhea, and were strongly associated with HIV infection. Efforts to improve child survival in AIDS infected populations will need to address HIV infections in both mothers and infants.     

Les effets de l’ayahuasca sur le système nerveux central: étude comportementale

An ayahuasca beverage sample, containing harmalol, harmol, harmane and N,N-Dimethyltryptamine alkaloids, was evaluated in the forced swimming and open field tests. In the forced swimming test, the doses have decreased the immobility time in inverse dose-dependant way. Doses of 2.5mg/kg and 10mg/kg of ayahuasca also decreased the locomotor activity and vertical exploration on open field test. The 2.5mg/kg dose decreased the locomotor activity in 44.95% and the vertical exploration in 62.12%. It is possible to suggest that doses are relationed in inverse dose-dependent way, and the 2.5mg/kg dose presented antidepressant activity.     

Annexin A1 subcellular expression in laryngeal squamous cell carcinoma

Aims: Annexin A1 (ANXA1) is a soluble cytoplasmic protein, moving to membranes when calcium levels are elevated. ANXA1 has also been shown to move to the nucleus or outside the cells, depending on tyrosine‐kinase signalling, thus interfering in cytoskeletal organization and cell differentiation, mostly in inflammatory and neoplastic processes. The aim was to investigate subcellular patterns of immunohistochemical expression of ANXA1 in neoplastic and non‐neoplastic samples from patients with laryngeal squamous cell carcinomas (LSCC), to elucidate the role of ANXA1 in laryngeal carcinogenesis. Methods and results: Serial analysis of gene expression experiments detected reduced expression of ANXA1 gene in LSCC compared with the corresponding non‐neoplastic margins. Quantitative polymerase chain reaction confirmed ANXA1 low expression in 15 LSCC and eight matched normal samples. Thus, we investigated subcellular patterns of immunohistochemical expression of ANXA1 in 241 paraffin‐embedded samples from 95 patients with LSCC. The results showed ANXA1 down‐regulation in dysplastic, tumourous and metastatic lesions and provided evidence for the progressive migration of ANXA1 from the nucleus towards the membrane during laryngeal tumorigenesis. Conclusions: ANXA1 dysregulation was observed early in laryngeal carcinogenesis, in intra‐epithelial neoplasms; it was not found related to prognostic parameters, such as nodal metastases.     

Rhythmic profiles of the late phase of acute myocardial infarction as a function of age]

OBJECTIVES: To evaluate the incidence of ventricular arrhythmias in the late phase of acute myocardial infarction (AMI) and to compare it with the following clinical parameters: age, sex, AMI localization, ventricular function (Killip classes), maximal creatinokinase (CK max) and the presence of sinus tachycardia. DESIGN: Prospective study, during a period of 31 months, of a non-selected group of patients with AMI. SETTING: Coronary Care Unit (UTIC-Arsénio Cordiero). PATIENTS: Non-selected group of 153 patients with acute myocardial infarction who survived the second week of disease. MATERIAL AND METHODS: 24-hour Holter ECG performed between the 4th and the 25th day of AMI. The patients were divided into two groups according to the hourly frequency of premature ventricular beats (PVB): less than 3 per hour (PVB less than 3/h) and 3 or more per hour (PVB greater than or equal to 3/h). RESULTS: PVB greater than or equal to 3/h occurred in 36 patients (24%). There was no differences in the occurrence of ventricular arrhythmias between sex, AMI localization, AMI size evaluated by CK max, and the presence of sinus tachycardia. Patients in Killip class III had more ventricular arrhythmias (67%) than patients in Killip class I (23%) (p less than 0.005), in Killip class II (18%) (p = 0.007), and in Killip IV (0%) (p = 0.017). In patients with serious left ventricular failure (classes III + IV) the ventricular arrhythmias were not significantly higher (40%) than in patients without serious left ventricular failure (classes I + II) (22%) (chi 2 = 2.5; p less than 0.25 NS). Patients with less than 41 years old had less PVB greater than or equal to 3/h (4%) than patients between ages 41-69 (24%) (p less than 0.05), and than patients over 70 years old (47%) (p = 0.00075). CONCLUSIONS: The majority of patients (76%) showed a low risk rithmic profile (PVB less than 3/h) in the late phase of AMI. Among all parameters the age of the patients was the one best related to the occurrence of ventricular arrhythmias. Sex, AMI localization, AMI size, and the presence of sinus tachycardia were not related to the presence of PVB. A slight tendency was found in patients with heart failure to have more PVB. On the other hand the elder group carried a statistically significant risk factor for a higher occurrence of ventricular premature beats.     

Pharmacology of an Indian-snuff obtained from Amazonian Maquira sclerophylla

The powdered bark of Maquira sclerophylla is consumed as snuff in north Brazil. Both the crude and the purified hydrosoluble extract (WP) injected i.p. in the dose range of 0.05-0.5 g/kg induced hyperexcitability, tremors, motor incoordination, ataxia, quietness and muscle relaxation in rats. The effects were progressive, dose-related and reversed after 30 min. Anesthetized rats, guinea-pigs and dogs injected with the purified extract (10-50 mg/kg, i.v.) showed a biphasic change of carotid blood pressure. The early and transient hypotension was blocked by atropine but not by vagotomy: the secondary hypertension was long lasting and sustained for over 30 min. The hypertension was shortened but not blocked after ganglionic blockade or reserpine treatment. Either pithing or alpha receptor blockade with yohimbine reduced both effects of the extract. Guinea-pigs and dogs were more responsive than rats and died by heart arrest. Incubation of WP (20 micrograms/ml) increased both the rate and force of contraction of isolated guinea-pig right atria by 2 and 5 times, respectively. Propranolol (4 micrograms/ml) blocked the chronotropic effect but did not decrease the inotropic effect. In electrically driven guinea-pig left atria, WP (10 micrograms/ml) increased the force of contraction by 80% and the maximum rate of force development by 60%, but did not change the time to peak tension, the time to 50% relaxation, or the rate of relaxation. These cardiovascular effects resemble those of digitalis-like drugs. Cardenolides were detected in WP by phytochemical screening.     

Pisosterol induces monocytic differentiation in HL-60 cells.

The aim of this study was to determine whether the antiproliferative effects observed for pisosterol, a cytotoxic triterpene isolated from Pisolithus tinctorius, are related to cell differentiation induction using HL-60 cell line as a model. Also, the effects of pisosterol on normal human cells were examined in peripheral blood mononuclear cells (PBMC). The effects on cell viability and morphological changes were the first indications showing that pisosterol induces HL-60 differentiation. The demonstration of blue tetrazolium reduction in HL-60 cells exposed to pisosterol demonstrated differentiation in a dose- and time-dependent manner, reaching a maximum effect after 72 h incubation at 5 microg/mL. Assays for alpha-naphthyl acetate esterase activity indicated that pisosterol triggers differentiation towards a monocytic cell-like pathway. The antiproliferative effect of pisosterol was determined by inhibition of DNA synthesis based on BrdU incorporation into HL-60 proliferating cells. It appears that pisosterol-treated cells, despite displaying a differentiated phenotype, continued to proliferate at all doses tested after 72 h, with a slightly decrease at 5 microg/mL. Apoptosis was observed in pisosterol-treated cells in a dose-dependent way. Nevertheless, after the same period of incubation, no cytotoxicity was detected in PBMC in the presence of pisosterol even at 25 microg/mL, providing some evidence that pisosterol may be selective for tumor cells. The mechanisms underlying the effect of pisosterol in leukemia cells indicates the induction of a monocytic cell-like differentiation, suggesting that this compound could be used in the development of new pharmacological tools with potential therapeutic value in the management of leukemia with fewer side effects.