Comparison of floor sanitation methods.

Two methods for cleaning waxed polyvinylchloride and porcelain grès hospital room floors were compared in order to determine their decontamination capacity: dry wiping followed by damp washing, and damp washing followed by dry wiping. Dry wiping followed by damp washing did not produce any significant reduction in the average bacterial load. However, damp washing followed by dry wiping reduced the bacterial load for both types of flooring. The difference was statistically significant.

A lower level of entropy in circadian rhythm of the sinus R-R intervals suggests a prevalence of the cardiac sympathetic regulation in early physiological pregnancy.

The study estimates the unpredictable disorder (chaos) within the 24 h pattern of sinus R-R intervals (SRRI) in clinically healthy pregnant women (CHPW) and clinically healthy non-pregnant women (CHNPW), in order to evaluate the early gestational changes in neurovegetative cardiac pacing. SRRI were provided by the 24-h Holter ECG of 10 CHPW and 10 CHNPW. SRRI were investigated by descriptive conventional statistics by means of the Time and Frequency Domain Analysis, and subsequently, in their chaotic component by means of entropy analysis. Both the SRRI and entropy were tested via the Cosinor method to better decipher whether or not the periodic disorder in heart rate variability is modified in pregnancy as a result of a gestational tonic resetting of the cardiac sympatho-vagal regulation. Cosinor analysis documented that the circadian rhythm of both the SRRI and entropy were preserved in CHNPW and CHPW. However, the circadian rhythm of SRRI and entropy in CHPW exhibited a significantly decreased 24 h mean. Via the analysis of the rhythmicity of entropy, this study has documented that the chaos in the 24 h pattern of SRRI is less prominent in CHPW than in CHNPW. Such a reduction of level in the deterministic periodic chaos of heart rate variability provides evidence that, in early pregnancy, a tonic elevation of the sympathetic activity regulates cardiac pacing.

Analysis of the chaotic component of the sinusal R-R intervals as a tool for detecting a silent cardiac dysautonomia in type 2 diabetes mellitus.

This study explores the heart rate (HR) variability (V) in order to detect whether the chaotic component of the sinusal R-R intervals (SRRI) can be interpreted as an early indicator of a silent cardiac neurovegetative dysautonomia in apparently uncomplicated Type 2 diabetic patients (DP). The SRRI were provided by the 24-h Holter ECG of 10 Type 2 DP (5 M and 5 F, mean age = 41 +/- 5 years). Control data were obtained by the 24-h Holter ECG of 10 clinically healthy subjects (CHS, 5 M and 5 F, mean age = 38 +/- 6 years). The chaotic component of HRV was investigated via the correlation dimension (CD) analysis (A) of the SRRI, performed per each hour of the ECG recording. The hourly-qualified series of SRRI, HR and CD index (I) were, in turn, analyzed via methods of conventional statistics and chronobiology, the latter ones for assessing the circadian rhythm (CR). The CDI CR was found to peak during the night in CHS, and to be unphysiologically rotated to the diurnal hours of the day in Type 2 DP. The diurnal inversion of the CDI CR in Type 2 DP suggests that the chaotic component of HRV shows an abnormal rhythnic pattern over the day-night period. Considering that the investigated Type 2 DP were lacking of documentable signs of cardiac neuropathy, it is hypothesized that the diurnal phase of shift CDI CR might be a potential indicator of a silent autonomic cardiac dysfunction in Type 2 DP. Such a hypothesis waits for further confirmations.

[When science becomes technology: epistemological and ethical consequences of the Adduction]. / Quando la scienza diviene tecnologia: conseguenze epistemologiche ed etiche della Adduzione.

Notwithstanding that the sciences are every day closest to technology, the Philosophy of Science has not yet well realized the epistemological and ethical differences that make different the "Traditional Naturalistic Science" (TNS) and the technological, artefactual, intrusive science that I called: "Post-Modern Meta-Naturalistic Science" (P-MM-NS). The first type of science has as a primary scope the knowledge of nature, using a methodology that departs from the methodic doubt, realizes a hypothesis, defines the aim(s), adopts a protocol, interprets and discusses the results, inferentially derives the conclusions, according to the classical philosophical reasonings of induction, deduction, abduction. In my philosophical reasoning, I realized that P-MM-NS follows an absolutely different epistemological procedure. The technological science prefigures a scope, produces a non-natural technically-modified object, gives for sure the occurrence of the effect for which the object has been manufactured. This means that only "in retrospect" it will ascertain whether or not the promised effect has occurred, considering that any technical artifact could be rejected by that natural environment in which it has been, acritically, delivered, without knowing how to remedy in case of an unexpected effect. In such a circumstance, the technological science has totally failed in its scope and effect, The potential failure of the predicted effect will prove that P-MM-NS follows a logical reasoning that is substantially and formally "sui generis" with respect to the epistemology and ethics of NS. This divergence from the classic reasoning of induction, deduction, abduction, has been called by me: "Adduction", because of the following considerations: the scientific procedure doesn't depart from the methodic doubt and hypothesis, only declares a scope, for which it is produced a technically-manufactured object, and gives for sure which will be the expected effect, but, not knowing how to remedy to negative results in case of a failure. It is, thus, clearly visible that the adduction is a type of logical reasoning that is self-referential and tautogical, being only based on a declaration of intents, adducted for justifying the production of a technical artifact, assuring an effect without suspecting that it could not respond to the promised scope.

Usefulness of twenty-four-hour blood pressure patterns and response to short-term sodium restriction in normotensive subjects in detecting a predisposition to systemic arterial hypertension.

Twenty clinically healthy subjects were studied to identify normotensive adults with a predisposition to arterial hypertension by monitoring blood pressure (BP) and restricting dietary sodium intake. Short-term restriction in sodium intake resulted in a decrease of the mean level for the circadian rhythm of BP. The phenomenon is visible in subjects without familial hypertension but not in individuals with a positive history for high BP. The response of the 24-hour BP patterns to abrupt sodium deprivation seems to be an indicator for discovering normotensive subjects at risk of developing arterial hypertension.

Blood pressure 24-hour pattern in two industrialized countries (Italy and Japan) with a different culture in salt intake.

This study investigates the blood pressure (BP) 24-hour pattern in representative samples of 2 industrialized countries, Italy and Japan, showing different cultures in salt intake. BP was monitored by means of a noninvasive ambulatory device whose readings were analyzed by means of chronobiometric procedures. The results show that the 24-hour BP pattern is not substantially different in Italian and Japanese subjects. In particular, the expected lower BP in the Italians was not detected despite their lower salt intake. Because the 24-hour mean BP value was seen not to be proportional to salt intake, the hypothesis is formulated that maintenance of the pressure regimen within a given range of variability is a principle of human physiology. To comply with this rule the Japanese people are supposed to have ethnically developed a certain resistance to dietary salt for which their cardiovascular apparatus is protected (phyletic escape to dietary sodium excess).

Preserved blood pressure and heart rate circadian rhythm in early stage Alzheimer's disease.

BACKGROUND: This study investigated the blood pressure (BP) values over the day-night period in 11 noninstitutionalized patients affected by probable Alzheimer's disease (AD) in its early stage. The scientific aim was to detect whether the BP circadian rhythm (CR) was preserved, given the fact that CR disruption was observed in advanced or institutionalized AD patients. METHODS: The BP within-day values were gathered via noninvasive ambulatory monitoring. The BP time series were analyzed according to the chronobiological procedure, called Cosinor method with three harmonic components. RESULTS: The biometric analysis was able to document that BP changes over the 24-h scale in AD patients as a function of a significant CR. Such a preserved circadian regulation is, however, compromised in the second and third harmonic component, suggesting that the BP within-day variability is desynchronized by the environmental clues that act as synchronizers during the diurnal part of the day. CONCLUSIONS: The preservation of the BP CR in the early stage of AD suggests using such a finding as a clinical tool for confirming the recent onset of the disease. As a matter of fact, it is presumed that the disease is not evolved enough to reach the suprachiasmatic nuclei, wherein is located the BP circadian pacemaker. The abolition of the ultradian components is another precocious sign that, in turn, indicates early-stage AD patients to be particularly compromised in their synchronization to diurnal cues, such as social routines, meal timing schedule, psycho-physical activity, and occupational schemes.

Twenty-four-hour pattern of hunger sensation in obesity complicated by type 2 diabetes mellitus: a pattern recognition by spectral analysis.

Hunger sensation (HS) in humans physiologically shows intraday (circadian) and within-day (ultradian) recursivity. This intrinsic periodicity was investigated by applying the cosinor method and spectral analysis to the 24-hour profile of HS (orexigram) derived by a self-rating score (from 1 to 10 hunger units [HU]) recorded every half-hour. The study of circadian and ultradian recursivity on the orexigram was performed in 30 diabetic obese patients ([DOPs], 14 men and 16 women aged 22 to 62 years; body weight, 77 to 130 kg; body mass index, 31-47). The control group consisted of 30 clinically healthy subjects ([CHS], 15 men and 15 women aged 21 to 60 years; body weight, 65 to 72 kg; body mass index, 23 to 25). DOPs showed two types of orexigrams in which hunger was felt with limitation to the diurnal part of the day or with extension to the night, respectively. The type 1 orexigram was characterized by a normal spectrum and circadian rhythm. The type 2 orexigram was characterized by subsidiary ultradian components associated with an abnormal elevation of the circadian mesor and a significant delay of the circadian phase, as the spectral analysis was indicative of a structural difference in the frequencies that sustain the intraday and within-day recursivity of the HS. Accordingly, DOPs can be recognized by their orexigram as "eurectic" or "hyperrectic" to indicate subjects with a normal or an exaggerated HS, respectively, during the 24-hour span.

Chronobiometric identification of disorders of hunger sensation in essential obesity: therapeutic effects of dexfenfluramine.

In human beings, hunger is a proprioceptive signal that shows intraday (circadian components) and within-day (ultradian components) recursivity. Both periodic components can be investigated by chronobiometric procedures by combining the Cosinor method with spectral analysis. A 24-hour profile of hunger sensation (HS) can be plotted on a 1-to-10 scale of intensity using self-rated scores performed every half-hour of the day. Circadian and ultradian components were studied in 60 patients affected by essential obesity (20 men and 40 women; mean age, 38.4 years; mean body weight, 101 kg) before and after treatment with dexfenfluramine (Isomeride; Servier, Orléans, France) 15 mg orally twice daily, for 30 days. The control group consisted of 30 clinically healthy subjects (15 men and 15 women; mean age, 37.5 years; mean body weight, 69 kg). Chronobiometric analysis shows three patterns in obese patients, which suggests that HS may be normal (eurectic obesity), exaggerated (hyperrectic obesity), or diminished (hyporectic obesity). After dexfenfluramine administration, HS was showed a substantial decrease in the daily mean level. The spectrum of resolution in circadian and ultradian components was found to be maintained in eurectic obesity and partially readjusted in hyperrectic and hyporectic obesities. This demonstrates that dexfenfluramine acts not only as an anorectic but also as a chronizer by interfering with the recursive components of HS. The anorectic and chronizing effects suggest that dexfenfluramine is a "chronoanorectic drug" that interacts with the chronobiologic properties of the serotoninergic system.

Vasoactive intestinal peptide fluctuates in human blood with a circadian rhythm.

The vasoactive intestinal peptide (VIP) may be radioimmunoassayed in systemic venous blood. The plasma concentrations of VIP were investigated in human blood according to a chronobiological design. The study documented a circadian rhythmicity in time-qualified concentrations of VIP. Accordingly, VIP may be ascribed to biological variables characterized by periodicity in their physiological attributes. The rhythmic physiology of VIP is, however, highly disturbed in its tonic and phasic properties during senescence.

Hospital use of decontaminating mats.

Decontaminating mats made of several layers of adhesive sheets (water-based acrylic 6 g/m2) supplemented with a bactericidal agent (3-1 benzoisothiazolin) at a concentration of 25% were placed in the passages providing access to the operating rooms of an orthopaedic service. Contact plates containing tryptone soy agar were used to assess bacterial concentration at specific points in front of and beyond the mats. For trolley passageways two areas were defined: central and lateral paths, corresponding to the areas walked upon by the personnel pushing the trolleys and to the paths covered by the trolley wheels, respectively. In order to exclude a simple mechanical effect, a comparison of bacterial loads at defined sites beyond the mats was carried out in the presence and in the absence of decontaminating mats. Bacterial colony counts in the presence of decontaminating mats were substantially and statistically significantly reduced compared with the absence of mats. The lower mean number of colony-forming units detected at points located beyond the mats parallels this finding; this difference is also statistically significant. We thus conclude that decontaminating mats are potentially useful in decreasing micro-organism carry-over due to personnel or the passage of trolleys into areas at high risk of infection such as operating rooms.

Endoscope washers--a protocol for their use.

A protocol for the disinfection of gastroduodenoscopes, retrograde cholangiopancreatography endoscopes and colonoscopes using endoscope washers is described. The process recommends initial manual washing with a disinfectant containing didecyldimethylammonium chloride, surfactants and enzymes, a second washing in the endoscope washer using a detergent associated with a bacteriostatic, fungistatic substance (benzoisothiazolone) and finally the use of a 2% glutaraldehyde product buffered at pH6. After treatment with 2% Steranios added to the washer, less than 1 micro-organism/ml liquid was found in the following units: 83% of the colonoscopes, 83% of the oesophagogastroduodenoscopes, 83% of the main channels of the retrograde cholangiopancreatography endoscopes and 75% of the auxiliary channels of the latter instruments. In 14% of the colonoscopes, 42% of the gastroduodenoscopes, 42% of the main and 50% of auxiliary channels in the retrograde cholangiopancreatography endoscopes there were no signs of microbial growth in the wash liquid. The results obtained indicated that this protocol allowed adequate disinfection of the endoscope channels, structurally the most difficult part of the instrument to disinfect. Emphasis is given to the degree by which instrument contamination can increase during overnight storage, suggesting that endoscopes need to be submitted to further disinfection after overnight storage. Moreover, the water flowing into the washers can also cause instrument recontamination, particularly during the final rinses. Therefore, to better safeguard the health of patients undergoing endoscopy, special care must be taken to maintain the filters and disinfect the washers themselves, no matter how effective the disinfection protocol used may be.

Circadian rhythm of blood pressure and life style: a study of clinically healthy subjects living in rural and industrialized countries.

The aim of this study is to investigate how the blood pressure (BP) circadian rhythm (CR) is influenced by life style. Two groups of subjects were recruited from Nepal and Japan because of the extremely different occupational routines of these countries. The Nepalese represent a rural culture, while the Japanese reflect an industrialized civilization. Both the ethnic groups have in common a high dietary sodium intake. The BP monitoring was estimated according to chronobiological methods. Results provide evidence for a phase difference in BP CR which is coherent with the life style in the two groups. Furthermore, the estimates demonstrate that the Japanese show a higher level in daily BP which is related to the greater number of hours in which they are active. These findings may be taken into account for better deciphering of what is the role of life style on BP physiology in human beings.

The relevance of continuous blood pressure monitoring in examining the relationship of memory efficiency with blood pressure characteristics.

The study of the relationship between hypertension and cognitive decline is characterized by various difficulties of realization and, as a consequence, by incongruent results. One of the reasons for these difficulties may be explained by the occasional method of measurement of blood pressure (once a day). This study presents the results obtained in 27 normotensive and mild hypertensive subjects of both sexes (ages between 20 and 77 years) with a continuous blood pressure monitoring for 24 h. A noninvasive sphygmomanometric technique was used employing a portable recorder programmed to take a measure every 30 min. Both objective and subjective measures of memory, measures of attention efficiency, and IQ were correlated to the blood pressure measures. Continuous monitoring data of blood pressure were analyzed according to a model that included a macroscopic descriptive analysis, a microscopic rhythmometric analysis, and a microscopic integrative analyses where the effects of the interaction between level and duration of excess and the time of the day when the excess eventually appeared were considered. Results evidenced no differences in cognitive efficiency between those subjects identified with the traditional occasional measurement of blood pressure as hypertensives of mild severity and the normal subjects. Cognitive efficiency of our subjects was found correlated, independently from the clinical diagnosis, with the time of peak and with the duration of excess of their blood pressure when the results of the analyses on the continuous monitoring of blood pressure were considered.

Twenty-four-hour pattern of atrial natriuretic peptide in heart transplantation: evidence for lack of circadian rhythm. Temporal inter-relationships with plasma renin activity, aldosterone and cortisol.

We have investigated the circadian rhythm of plasma atrial natriuretic peptide in 13 stable output heart transplanted patients, all without evidence of histological rejection and cardiac impairment, following antirejection therapy with Cyclosporine, Azathioprine and Prednisone. The 24-h pattern of plasma renin activity, plasma aldosterone and plasma cortisol has been studied as well. All the investigated variables were assayed six times over the 24-h span. The circadian time-qualified data were analyzed by ANOVA and Cosinor method. The 24-h mean levels of atrial natriuretic peptide, plasma renin activity and plasma aldosterone are significantly increased, while the concentrations of plasma cortisol are reduced in the heart transplanted recipients. ANOVA detected a significant within-day variability of all these humoral variables only in healthy subjects. A statistically significant circadian rhythm was validated by Cosinor procedure for all the investigated molecules in healthy subjects but not in heart transplanted patients. In our opinion, the increase of atrial natriuretic peptide is a counterregulatory mechanism aimed to compensate the cyclosporine-mediated activation of the renin-angiotensin-aldosterone system. The disappearance of the plasma renin activity, aldosterone and atrial natriuretic peptide circadian rhythm can be ascribed to the constant activation of the renin-angiotensin-aldosterone system. The hypocortisolism is due, in our opinion, both to glucocorticoid therapy and increase of plasma ANP concentration.

Temporal correlation of some endocrine circadian rhythms in elderly subjects.

The aim of this chronobiological study was to investigate temporal correlations in the circadian patterns of 6 hormones, namely somatotrophic hormone (STH), prolactin (PRL), cortisol (F), aldosterone (ALD), insulin (IRI) and C-peptide (CP), assayed in systemic blood serum drawn at 07:00, 10:00, 13:00, 16:00, 19:00 and 22:00 h from an antecubital vein in 19 young subjects (aged 20-29 yr, comprising 10 males and 9 females; and 20 elderly subjects (aged 70-81 yr, comprising 10 males and 10 females). All subjects were sampled on a normal dietary sodium intake (120-140 mEq/24h) while following a social routine of diurnal activity (07:00-23:00) and nocturnal rest (23:00-07:00). Time-qualified data were analyzed by lead-lag correlation and by cosinor analysis. According to the lead-lag correlation findings, it would appear that the correlation which exists between several time-qualified series in young subjects is no longer present in elderly subjects. The circadian rhythms which were found to have lost their temporal correlations with advancing age were those between STH and IRI, STH and ALD, PRL and IRI, PRL and CP, and ALD and CP. It should be noted that the correlation between hormonal rhythms breaks down mainly on account of a peculiar age-related change in the magnitude of the circadian fluctuation. This chronological decline in amplitude led to the conclusion that the senescence of endocrine rhythmic functions is a biological phenomenon characterized by altered circadian variability.

Effect of ageing on circadian rhythms of plasma renin and aldosterone in mesor-hypertensive women.

This study investigated the changes in circadian rhythms of plasma renin activity (PRA) and plasma aldosterone (PA) which occur in essential mesor-hypertensive women, increasing in age. Systemic blood samples were taken throughout a 12 h period from both mesor-hypertensive women and clinically healthy women (control). The women in each group were either post-menopausal or had normal menstrual cycles. A cosinor method of temporal series was the analysis employed to compute the properties of PRA and PA circadian rhythms. The clearest effect of ageing, recorded in essential mesor-hypertensive women, is a decrease in circadian mesor of PRA cycle (P = 0.002). The age-related changes in clinically healthy women appear to be more extensive and involve a decrease for both mesor (P less than 0.001) and amplitude (P = 0.007) of PRA circadian rhythm. These disparities are convincing evidence for a non-physiological decline of the RAAS rhythmic function in the aged essential mesor-hypertensive women. The lack of an age-associated decrease in circadian PRA amplitude merits and pathophysiological and clinical investigation because it is a possible risk factor for post-menopausal, essential mesor-hypertensive women.

Ageing and circadian rhythm of plasma renin and aldosterone.

Five men and 8 women, 60-69 yr of age, and 4 men and 5 women, 17-37 yr of age, volunteered for this exploration of possible age-related changes in circadian-rhythm (CR) characteristics of radioimmunoassayable plasma renin (PRA) and aldosterone (PA). Blood was drawn at 06.00, 08.00, 12.00, 18.00, 20.00 and 24.00 from recumbent subjects on a habitual sodium intake of 120-140 mEq/24 h. Time-qualified data of PRA and PA, fitted by a 24-h cosine curve, were summarized by a population mean-cosinor method. Circadian characteristics were compared by a multivariate analysis using Hotelling's t2 test. Rhythmometry reveals in the elderly women a lower mesor (P less than 0.001) and amplitude (P = 0.036) of the CR in PRA and a higher mesor and amplitude (P = 0.021 and P = 0.020, respectively) of the PA-CR. The PRA acrophase is delayed (P less than 0.001) in the elderly women (04.40 vs. 08.04) while the timing of the PA acrophase is similar in the age groups of women compared (05.52 vs. 05.20). These differences found in women were not observed in the smaller groups of men. The seventh decade of life may be characterized by an internal circadian desynchronization between the major components of the renin-angiotensin-aldosterone system. A sex-dependent amplification of the extent of circadian variation in aldosterone may precede a decrease in the circadian amplitude occurring during the eighth decade of life, as a sign of the adrenopause in women.

Day-time changes for pituitary-thyroid hormones denote a rhythmic structure not detectable in elderly subjects.

The day-time concentrations of TSH, T3, T4, FT3 and FT4 were investigated in clinically healthy volunteers, 20 young individuals, aged from 20 to 27 years, and 12 elderly subjects, aged from 70 to 81 years. Nocturnal sampling was purposely avoided in order to eliminate the interindividual differences in sleep patterns. The day-time series were analysed by means of cosinor analysis to interpolate the best-fitting sinusoidal wave that covers the day-night period. The reconstruction of the circadian sinusoidal wave was validated for TSH, T3, T4, FT3 and FT4 in young subjects, and, with limitation, for T4 in elderly individuals. The findings suggest that the day time patterns of TSH, T3, FT4 and FT3 in elderly subjects are characterized by a dyschronism that is not detectable in young subjects. The investigation of the day-time concentrations is suggested as a cost-effective tool for exploring the circadian cycle of the pituitary-thyroid hormones in aged people.

Common migraine as a weekly and seasonal headache.

The aim of this study was to demonstrate that a possible recurrence may pertain to migraine attacks (MAs). The study was carried out by checking the personal diaries of 30 migraine sufferers ("migraineurs") who carefully annotated the date of their MA over twelve consecutive months. The group was composed of 15 males and 15 females, ranging in age from 17 to 37 years. The individual MAs were summarized in order to obtain the time-qualified frequency per each time period of recurrence. The periodicity in time data series was analysed by means of the Single Cosinor method. The rhythmometric analysis was found to be highly statistically significant; the circaseptan (P = 0.007) and circadian (P = 0.004) recurrence of MA showing critical incidence on Sunday and in January, respectively. No circatrigintan periodicity was validated in relation to the solar and lunar months or menstrual cycle. These findings suggest to us a possible linkage of MA to environmental factors which entrain the routine of our lives. Because of the circaseptan and circannual repetitivities, common migraine syndrome was defined as a "weekly and seasonal headache".