Longevity of silicone and polyurethane catheters in long-term enteral feeding via percutaneous endoscopic gastrostomy.

BACKGROUND: As percutaneous endoscopic gastrostomy (PEG) is often used for many months or years, the longevity of the feeding tubes plays an important role in the global outcome and costs of PEG. AIM: A retrospective study to evaluate the longevity of silicone and polyurethane PEG catheters. METHODS: The records of 297 patients who were fed via PEG for over 90 days were evaluated. The material of the PEG catheter, duration of follow-up, local complications, need to remove PEG because of tube deterioration or local complications and time from PEG placement to PEG removal were recorded and compared. RESULTS: Two hundred and twenty-eight patients had polyurethane and 69 had silicone PEG catheters. The follow-up ranged from 116 to 3207 days for the polyurethane group and from 98 to 1861 days for the silicone group. No differences were observed in either local complications or PEG removal because of local complications. Tube deterioration causing PEG removal occurred in 36 of the 228 polyurethane PEG catheters and in 25 of the 69 silicone PEG catheters (P = 0.0005). Tube deterioration occurred significantly earlier in the 25 silicone catheters than in the 36 polyurethane catheters. The mean time from PEG placement to PEG removal was 287 days (95% confidence interval, 239-335) for silicone tubes and 573.9 days (95% confidence interval, 425-723) for polyurethane tubes (P = 0.0024). CONCLUSION: Polyurethane PEG catheters seem to be more resistant to deterioration than silicone PEG catheters, and at present they should be preferred for long-term enteral feeding via PEG.

Who are the non-dippers? A better definition via the blood pressure circadian rhythm.

OBJECTIVE: The non-dipping phenomenon (NDP) can be better interpreted when considering that blood pressure (BP) shows a within-day variability which is the expression of a circadian rhythm (CR). PATIENTS AND METHODS: The NDP was investigated at the light of the BP CR by analysing the ambulatory BP monitoring of 298 essential hypertensive patients (EHP), 84 secondary hypertensive patients (SHP), as well as 93 normotensive subjects (NS). According to the rhythmometric validation, the investigated subjects were defined "rhythmic" (R) or "non-rhythmic" (NR). RESULTS: The non-dippers (ND) were found among not only the EHP (14%) and SHP (27%) but also the NS (16%). The percentages of R ND were 9%, 4% and 20%, respectively in EHP, SHP and NS. The R ND were characterized by a nocturnal phase-shift (100% in NS), associated with an amplitude increase (50% in EHP) or a mesor increase (50% in EHP; 100% in SHP) in BP CR. The NR ND were characterized by an amplitude almost negligible (100% in NS) associated with a mesor increase (100% in EHP; 100% in SHP). CONCLUSIONS: The detection of a NDP associated with a rhythmicity suggests that the criterion with which the ND are identified cannot be used for making inferences on the BP CR in HP or NS. The rhythmic characteristics in ND suggest that the rhythmometric analysis is fundamental for identifying the abnormal time structure of BP 24-h values in the presence of the NDP.

Hunger sensation in Graves' disease before and after pharmacological therapy.

PURPOSE: Hunger sensation (HS) provides information about the need of eating in order to counterbalance the energy expenditure (EE). HS was, thus, investigated in patients affected by Graves' disease (PAGD), a clinical condition characterized by excessive EE. MATERIALS AND METHODS: Ten newly diagnosed PAGD were investigated before and after therapy. Thirty clinically healthy subjects (CHS) were investigated as controls. The investigated subjects were asked to provide the 24-h profile of their HS by subjectively self-rating (from 1 to 10 hunger units) their orectic perception (OP) at regular intervals of 30 minutes (orexigram). The orexigrams were investigated via the conventional descriptive statistics as well as the Single-Cosinor method. RESULTS: PAGD were found to show a very consistent increase of their HS (hyperorexia), whose day-night variability was, still, the expression of a circadian rhythm, characterized by an elevation in its oscillatory level and extent. Interestingly, the pre-treatment hyperorexia was seen to show a normalization (eurexia) after pharmacological therapy. CONCLUSIONS: According to these results, it can be affirmed that hyperorexia is a clinical sign of Graves' disease, which is obtained via mechanisms of tonic and amplitude modulation of the HS circadian rhythm. Because of the eurexia after remission, it can be argued that the hyperorexia is a theleological response really aimed at increasing food intake in order to counterbalance the excessive EE which characterizes the thyrotoxicosis.

Properties of chicken skeletal muscle pyruvate kinase and a proposal for its evolutionary relationship to the other avian and mammalian isozymes.

Pyruvate kinase (EC 2.7.1.40) was isolated and purified from chicken and turkey breast muscle with a purification procedure very similar to that used for the bovine skeletal muscle isozyme (Cardenas, J., Dyson, R., and strandholm, J. (1973), J. Biol. Chem. 248,6931). A study of the chemical and physical properties of the chicken enzyme revealed that it is a tetramer of four apparently identical subunits, closely resembling in this and most other respects the mamalian type 7 isozyme. The properties of these two enzymes are similar enough to permit subunits of chicken type M pyruvate kinase to combine with subunits of mammalian type L (one of the three mammalian isozymes) to form interspecies tetrameric hybrid isozymes in relative quantities that do not differ makedly from those formed when both the M and L isozymes are of mammalian origin. The similarity between the mammalian and avian type M pyruvates kinases suggests a close evolutionary relationship. Further comparisons among the three mammalian and two avian isozymes of pyruvate kinase are consistent with a common evolutionary origin, perhaps from an ancestral form of the type K isozyme, which is the only pyruvate kinase identified in mammalian and avian embryos.

Bone morphogenesis in implants of insoluble bone gelatin.

Insoluble bone gelatin with inclusions of insoluble noncollagenous protein produces new bone when implanted in muscle in allogeneic rats. The implanted residue provides the milieu for expression of bone morphogenetic potential of migratory mesenchymal cells. Neutral buffer solutions activate endogenous enzymes that degrade components essential for cell interactions and differentiation of bone. Chloroform-methanol either denatures or extracts constituents responsible for degradation. Insoluble bone gelatin produces new bone after extraction at 2 degrees with neutral salts, 0.5 M EDTA, 0.1 M Tris.HCl, 4 M urea, 0.5 M hydroxylamine, and 10 M KCNS, as well as after limited digestion with pepsin or collagenase, but not after extraction with 5 M guanidine, 7 M urea, water saturated with phenol, or after alkali hydrolysis with 0.1 N NaOH. The specific activity of cell populations interacting with insoluble bone gelatin suggests that a chemical bond between collagen and a noncollagenous protein or part of a protein, cleaved by a neutral proteinase, controls the bone morphogenetic reaction.

Hunger sensation: a chronobiometric approach to its within-day and intra-day recursivity in anorexia nervosa restricting type.

Hunger sensation (HS) is a perception with a daily (circadian) and within-day (ultradian) recursive pattern. In human beings, circadian repeatability was investigated by means of the Single Cosinor method, while the ultradian recursivity was investigated by means of the spectral analysis, both applied to the 24-h HS profile (orexigram). Orexigrams were provided by each subject investigated, who self-rated her subjective orectic stimulus (OS) (from 1 to 10 hunger units) every half hour. The study was performed in 19 female patients aged 13-52 newly diagnosed as in the first episode of Anorexia Nervosa Restricting Type, with a BMI below 18.7. The control group consisted of 10 clinically healthy women aged 21 to 52 years with a BMI from 23 to 25. Two types of orexigrams were found. The first was characterized by a low profile with negligible ultradian variability, in which the HS circadian rhythm (CR) was still detectable, but the power spectrum (PS) was composed of unusual ultradian components associated with a very diminished amplitude for the circadian harmonics. The second was characterized by an almost regular profile, in which the ultradian variability was clearly detectable, the CR regularly fluctuated, and the PS was almost regularly composed. These findings indicate that anorectic patients (AP) can be recognized by their orexigram as "hyporectic", or "eurectic". Therefore, the term "anorexia" seems to be appropriate for AP who exhibit the first type of orexigram (anorectic aphagia nervosa), whereas the second identifying those who could be defined as suffering from "eurectic aphagia nervosa".

Daily hunger sensation and body composition: I. Their relationships in clinically healthy subjects.

The human hunger sensation (HS) is a perceptive signal characterized by day-night variability (DNV). This pattern was investigated with respect to its relations with the body compartments in 22 clinically healthy subjects (CHS, 11 males and 11 females, mean age: 24 +/- 2.5 years, mean BMI: 21 +/- 1.7). The DNV was investigated by means of conventional descriptive statistics and the single cosinor method (SCM). Both procedures were applied to the orexigram, i.e., the 24-h profile of the orectic stimulus (OS) provided by each subject, who self-rated his/her HS (from 1 to 10 hunger units) every half hour. Body composition was investigated by Bioelectrical Impedance Analysis (BIA) on the day when the orexigrams were compiled. It was found that the daily HS level correlates positively with the Free Fat Body Mass (FFBM) and negatively with the Fat Body Mass (FBM). These opposite relations indicate that HS is stimulated by the needs of the FFBM, and inhibited by expansion of the FBM, and provide further evidence of the existence of an "adipostat" anorectic mechanism.

Anxiety, depression, hunger and body composition: III. Their relationships in obese patients.

The present paper explores the relationships between anxiety, depression, hunger sensation and body composition in obese patients (OP). The aim is to detect whether or not there are abnormalities in these relationships in OP as compared to clinically healthy subjects (CHS). The study was performed on 22 CHS (2 M, 20 W; mean age = 24 +/- 2 years; mean body mass index = 21 +/- 2 kg/m2) and 48 OP (4 M, 44 W; mean age = 40 +/- 17 years; mean body mass index = 32 +/- 7 kg/m2). Anxiety and depression were found to be correlated, negatively, with the relative lean body mass, and, positively, with the fat body mass in OP but not in CHS. These findings corroborate the idea that anxiety and depression can reach an abnormal expression when obesity shows its worst loss in lean body mass and its highest expansion in adipocyte mass. As hunger sensation was found not to correlate with either anxiety or depression in OP, the opinion is expressed that the impairment of anxio-depressive integrity is a corollary of obesity rather than a primary affective disorder leading to obesity via an enhanced food intake.

Daily hunger sensation and body compartments: II. Their relationships in obese patients.

Hunger sensation (HS) is a signal whose levels change during the 24-h day. The daily mean level of HS was correlated with the human body compartments, as investigated by bioelectrical impedance analysis, to detect the relationship between the orectic perception and both the free fat mass (FFM) and the fat body mass (FBM) in 22 clinically healthy subjects (CHS) (2 M, 20 W, BMI: 18.5-24.0 kg/m2) and 48 obese patients (OP) (4 M, 44 W, BMI: 25.2-54.7 kg/m2). In CHS, the daily mean level of HS correlated positively with the FFM and negatively with the FBM. These correlations were not present in OP. This lack of relationships between HS and the body compartments where energy is maximally consumed (i.e., the FFM) and maximally stored (i.e., the FBM) indicates that the orectic response to energy expenditure and the orectic inhibition to fat accumulation are feedback mechanisms which are impaired in obesity.