Considerations on 2 cases of accidental hanging in 3-year-old children]

Two cases of accidental hanging that occurred at school in comparable circumstances in two three-year-olds are reported. The opposite outcomes in these two cases together with data from a review of the literature highlight the importance of first aid training to give victims of such injuries the best chance of survival.     

Detection of arrhythmogenic cellular magnesium depletion in hip surgery patients

The use of high-dose magnesium infusions in critically ill and surgical patients is increasing. This practice is associated with considerable risk of toxicity, as no reliable criteria are currently available to detect significant intracellular magnesium depletion. We have evaluated, before and after surgery, 33 elderly patients with hip fracture, by 24-h Holter ECG monitoring, Doppler echocardiography and serum chemistry; lymphocyte magnesium was measured using atomic absorption spectrophotometry. The severity of ventricular arrhythmias increased, and serum and mononuclear magnesium concentrations decreased significantly after surgery. Decreases in either serum magnesium concentrations > 0.125 mmol litre-1 or cellular magnesium > 6 nmol mg- 1, but not serum or lymphocyte absolute magnesium concentrations, were associated with postoperative development of repetitive arrhythmias. Variations in serum magnesium concentrations correlated with intracellular decreases, and yielded good accuracy in predicting the postoperative worsening of arrhythmias. Thus perioperative differences in serum magnesium concentrations reflected intracellular variations and allowed us to identify patients with clinically relevant cellular magnesium depletion.      

Cranioplasty with autogenous autoclaved calvarial bone flap in the cases of tumoural invasion

Summary When a bone flap is raised in the course of a craniotomy, the ideal is to replace it at the end of the procedure. When it is invaded by tumoural cells, it cannot be replaced due to the risk of tumoural recurrence. In these cases we have autoclaved the bone flap to be able to replace it with no fear of tumoural recurrence.Between October 1989 and October 1995 sixty-two patients required autoclaving of the bone flap in the course of a craniotomy due to tumoural invasion (thirty-five meningiomas, sixteen bone tumours, five metastases, and eight scalp tumours).The infiltrated bone flaps were removed, cleaned, autoclaved for 20 minutes at 134 °C and 1 kg/cm² and re-implanted.Patients were followed-up for 10 to 58 months (average 41 months). At every follow-up visit skull x-ray studies, clinical examination, and photographs were done. When needed a CT scan was performed to assess the thickness of the bone flap.On follow-up roentgenograms partial resorption was observed in twelve cases (19.3%). CT scan studies showed loss of thickness in another thirty-five cases (56.4%). Meanwhile the external aspect remained unchanged.In six cases (3.2%) biopsies of the bone flaps were taken at a second surgical procedure. They showed newly formed bone partly re-populated by osteocytes but retaining areas of sequestered bone.We conclude that autoclaved bone, if replaced with direct contact with living bone, it is gradually repopulated with osteocytes. Cranial vault autoclaved autologous bone flap is a good alternative when the original bone flap is invaded but not destroyed by tumoural cells.     

Effect of dipyridamole with or without aspirin on urine protein excretion in patients with membranous glomerulonephritis

Summary The antiproteinuric effect of the antiplatelet agent dipyridamole has been assessed after inhibiton of thromboxane B₂ (TxB₂) synthesis in 8 patients with confirmed membranous glomerulonephritis. There were three study periods, each of 30 days, and 45 days apart, namely a washout period, treatment with dipyridamole 300 mg/d, and dipyridamole 225 mg/d plus aspirin 150 mg/d. On Days 1 and 30 of each study period serum and urine creatinine, 24-h excretion of protein, creatinine clearance, platelet aggregometry on whole blood and serum TxB₂ were measured. Treatment with dipyridamole alone or with aspirin produced significant inhibition of platelet aggregation and a fall in 24-h protein excretion; the latter amounted to 54% with dipyridamole alone and 56 % with dipyridamole plus aspirin (NS). Dipyridamole plus aspirin caused an 82 % reduction in serum TxB₂.     

A model to predict long-term sustained response to interferon therapy in chronic hepatitis C

Interferon therapy is used widely for chronic hepatitis C but only a minority of treated patients achieve a long-lasting sustained response. We have developed, by logistic regression, a mathematical model to estimate the probability of sustained response in an individual patient with chronic hepatitis C when treated with interferon-α (IFN-α). The model, which includes age, sex, disease duration, pretreatment serum γ-glutamyl-transpeptidase, alanine aminotransferase and virus genotype, was developed from a database of 307 patients and validated in a new set of 200 patients. It performed well as goodness-of-fit ( P = 0.71 and P = 0.15 in the development and test sample, respectively) and discrimination (area under receiver operating curve = 0.79 in the development and 0.78 in the test sample, respectively). This model may provide decision support in the treatment of chronic hepatitis C with IFN-α.     

Early gamma interferon responses in lethal and nonlethal murine blood-stage malaria.

This study was undertaken to explore early differences in cytokine production during nonlethal and lethal blood-stage murine malaria infections. Cytokine analysis of spleens during these infections showed that the principal difference between two nonlethal and two lethal Plasmodium species was the production of gamma interferon 24 h after infection with nonlethal parasites. In contrast, no increases in interleukin-4 production were observed in the first 24 h and tumor necrosis factor alpha levels increased equally in both nonlethal and lethal infections. During the later phase of infection with nonlethal parasites, both gamma interferon and interleukin-4 levels increased markedly a few days before parasite clearance. Early increases in gamma interferon production in nonlethal infections of Plasmodium yoelii and Plasmodium chabaudi were dose related and increased significantly with the size of the inoculum. Studies with the nonlethal P. yoelii suggest that the early gamma interferon response is mediated by T cells and natural killer cells, as it was reduced in athymic mice and in mice depleted of their natural killer cells by treatment with specific antiserum. Infecting mice with increasing numbers of lethal P. yoelii and Plasmodium berghei parasites did not increase the amount of gamma interferon, interleukin-4, and tumor necrosis factor alpha produced in a dose-dependent fashion. We conclude that one consequence of the early production of gamma interferon and tumor necrosis factor-alpha, particularly after nonlethal P. yoelii infection, may be to adjust the balance of T-helper cell subset activation, and probably that of other immune responses, so as to enhance the mechanisms that are essential for elimination of the parasites. This suggests that a successful vaccine should contain antigens capable of inducing such responses.     

Uptake and intracellular distribution of idarubicin in secondary cultures of normal and neoplastic urothelium

This study analyzes the uptake and endocellular distribution of idarubicin (IDA) in normal and neoplastic urothelial secondary cultures in relation to the changes in concentration and time of exposure. The urothelial lines were isolated by Freshney's method from biopsy fragments taken from five patients with superficial bladder cancer. Pharmacological experiments were carried out on subcultures previously immunophenotypically characterized and did not exceed ten passages. The uptake and endocellular distribution of IDA was analyzed by densitometric image analysis on cells treated for 10, 20, 30 and 60 min and 2 h with scalar dosages from 10 ng/ml to 2430 ng/ml. Microscopic observations and densitometric analyzes revealed that in the cells treated with IDA, fluorescence was higher in the cytoplasm compared to the nucleus and increased with the change in dosage. Moreover, densitometric data showed that IDA uptake in the first 20 min was higher in the neoplastic cells, but after that period its behavior became heterogeneous at 30 and 60 min, while at 2 h there was an inversion of the trend. These results suggest that the in vitro cytotoxicity should be evaluated in order to verify whether the elevated uptake of IDA in the first 20 min of treatment is really correlated to a more elevated toxicity in the neoplastic cells with respect to the normal cells. This is presently under investigation.     

Rearrangement of centromeric satellite DNA in hippocampal neurons exhibiting long-term potentiation.

In situ hybridization in conjunction with three-dimensional reconstruction was used to examine the topology of satellite DNA (sDNA) sequences in hippocampal CA1 neurons. In slices fixed immediately after preparation, 4-5 signals/nucleus were detected in CA1, CA3 and dentate neurons. 70-80% of 154 neurons examined in these 3 areas displayed all signals at the nuclear periphery. In the remaining fraction of neurons, sDNA signals were divided between the nucleolus and the nuclear periphery. sDNA signals were consistently localized to the nuclear midplane. Slices left to equilibrate in artificial cerebral spinal fluid for 1 h, in the absence of potentiation, exhibited a significant increase in the total number of signals/nucleus in CA1 and dentate neurons. This increase in the number of signals occurred in both nucleolar and peripheral compartments, with the number of the nucleolar compartment nearly doubling. The total number of signals/nucleus was found to be consistently reduced in tetanized CA1 neurons (4.89 +/- 0.09 signals/nucleus, n = 195, P less than 0.05) as compared to neurons from unpotentiated slices (5.27 +/- 0.10 signals/nucleus, n = 81). A similar decrease in the total number of signals/nucleus was also observed in CA1 neurons exposed to N-methyl-D-aspartate (NMDA), from 5.27 +/- 0.10 signals/nucleus (n = 81) to 5.00 +/- 0.08 signals/nucleus (n = 215, P less than 0.05). In contrast, dentate neurons, employed as internal controls, did not exhibit any change in number and compartmentalization of sDNA signals.(ABSTRACT TRUNCATED AT 250 WORDS)