[Autonomic and somatic neuropathy in the diabetic patient: electric clinical analysis]. / Neuropatía autonómica y neuropatía somática en el paciente diabético: análisis electroclínico.

INTRODUCTION AND OBJECTIVE: Neuropathy is the more often complication in the diabetic patients. The relationship between somatic and autonomic neuropathy has not been studied on these patients, so we decided to compare both situations. PATIENTS AND METHODS: We have performed a comparative study among clinical elements, the nerve conduction study (NCS) and the autonomic cardiovascular function in 120 insulin dependent diabetics patients. We use clinical scales, the NCS and the heart rate variability study (HRVS) to know de autonomic cardiovascular function. RESULTS: Sensation was the clinical manifestation more compromised and there was not correlation between clinical manifestation and the HRVS. In the NCS the nerve conduction velocity was the element more affected and the nerve more compromised was the sural; there was good correlation between NCS and HRVS. Fifty per cent of patients had some degree of neuropathy, and the duration of the disease was an important factor on this damage. The clinical elements, the NCS and the HRVS together let us classified patients in: patients without neuropathy (10 cases), patients with somatic neuropathy (31 cases), patients with autonomic neuropathy (7 cases), patients with somatic-autonomic neuropathy (72 cases). CONCLUSIONS: To defined the diagnosis of cardiovascular autonomic neuropathy (CAN) is necessary the HRVS, the subclinical presentations of CAN are often without manifestation. There is a close relationship between the somatic and autonomic nerve damage, influenced by the duration of the disease.

Cardiovascular autonomic dysfunction in sickle cell anemia: a possible risk factor for sudden death?

Cardiovascular autonomic function tests were performed in 24 patients with sickle cell anemia (SCA). Twenty-five healthy Afro-Caribbean black subjects and 38 healthy white subjects of Hispanic origin served as controls. Measurements based on heart rate variability (HRV) included the coefficient of variation (the standard deviation of the distribution of R-R intervals divided by the mean) and spectral analysis (low- and high-frequency bands) at rest, HRV during deep breathing (expiration-inspiration difference), Valsalva maneuver (Valsalva ratio) and lying-to-standing test (30:15 ratio). Fourteen patients (58.3%) were found to have cardiovascular autonomic dysfunction based on abnormal values for at least two cardiovascular autonomic function tests, whereas ten (41.7%) had preserved cardiovascular autonomic function. In contrast, all control subjects had normal cardiac autonomic function. SCA is known to be associated with sudden death. Involvement of autonomic nervous dysfunction in sudden death has been reported in various diseases and we suggest that this may be the case in SCA.

[Studies of cardiovascular autonomic function and duration of QTc interval in smokers]. / Estudios de función autonómica cardiovascular y duración del intervalo QTc en sujetos fumadores.

OBJECTIVES: A total of 97 apparently healthy subjects were studied in order to establish the influence of smoking habits in studies on neurocardiovascular control and the QTc interval duration. MATERIAL AND METHODS: The study group consisted of 37 smokers and 60 non-smokers as the control. A 12-lead electrocardiogram was performed on all subjects to determine the duration of the QTc interval. Other aspects studied include heart rate variability at rest during 150 cardiac cycles using time domain: coefficient of variation and root mean squared successive difference; and frequency domain: low frequency band (0.04-0.15 Hz) and high frequency band (0.15-0.50 Hz), to determine total energy logarithm and maximum energy frequency. Additionally, conventional cardiovascular autonomic function tests, such as orthostasis, Valsalva maneuver and deep breathing were performed. RESULTS: No significant differences were observed in the duration of the QTc interval nor in time and frequency domain parameters, except in the maximum frequency in the high frequency band, which appeared significantly lower (p < 0.05) in smokers when compared to non-smokers (0.28 +1- 0.1 vs 0.33 +/- 0.1 Hz). No modifications were noted in the cardiovascular autonomic function tests applied to smokers and non-smokers, and the QTc interval was not linked to the rest of the variables studied. CONCLUSIONS: To conclude, smoking habits do not seem to have a significant influence in studies addressed to determine the impact of the autonomic nervous systems on cardiovascular control.

A flow cytometric study of DNA staining in situ in exponentially growing and stationary Euglena gracilis.

DNA stainability by different fluorochromes has been compared in exponentially dividing and stationary Euglena cells. With the intercalating fluorochromes, ethidium bromide, acridine orange and DAPI, a decrease of fluorescence intensity of the G1 cells is observed when cells enter stationary stage. However this decrease of fluorescence is not obtained with the nonintercalating fluorochrome Hoechst 33258. If nuclear basic proteins are extracted, however, the intensity of staining by either Hoechst 33258 or ethidium-bromide is comparable in stationary and dividing cells. Therefore, the decrease of fluorescence intensity of the G1 cells observed during the transition from exponential to stationary phase is not due to a loss of DNA but is related to the exposure of chromatin binding sites for ethidium bromide. In Euglena cells, DNA accessibility for intercalating fluorochromes depends upon chromatin structure and consequently upon cell age.

Cadmium-induced ultrastructural changes in Euglena cells.

The ultrastructure of Euglena gracilis grown in the presence of Cd showed only numerous myelin-like structures in mitochondria, chloroplasts altered in shape, and thylakoid arrangement and increase of osmiophilic plastoglobuli. These alterations indicate that respiratory processes are the initial target of Cd toxicity.

Flow fluorometric study of DNA content in nonproliferative Euglena gracilis cells and during proliferation.

Ethanol-fixed Euglena gracilis cells have been analyzed by flow microfluorometry during the lag, logarithmic and stationary phases. The histogram of a plateau stage culture reveals, as expected, an unimodal distribution, but the peak is at lower fluorescence intensity as compared to G1 logarithmic cells. The fluorescence intensity drops as the cells enter the stationary stage. Ultimately the decrease represents a change of about 25%. When cells recover from the plateau stage, the fluorescence intensity increases during the lag phase, and climbs to the level found in a G1 logarithmic population. The reason for the decrease in the fluorescence intensity during the stationary stage may be due to a possible loss of DNA or to a decrease in the number of chromatin-binding sites for intercalating ethidium bromide.

[The effect of 3 mercury derivatives on the growth of Euglena gracilis Z]. / Influence de trois dérivés mercuriels sur la croissance d'Euglena gracilis Z.

The study of the toxicity of three mercuric derivatives on the growth of Euglena gracilis Z. shows that these chemicals act according to two different ways: quick inhibition of the growth for a peculiar concentration or progressive inhibition characterized by a lag-phase, the significance of which is discussed.