Reversed bowel segments for the treatment of short bowel syndrome: assessment of their minimal length in correlation with electromyographic pattern in the rat

Reversal of a distal intestinal loop is a surgical therapy intended to cure rapid intestinal transit in short bowel syndrome. To be active, a reversed loop must present a retrograde propagation of electromyographic patterns and must not be so long as to cause total obstruction. The aim of the current study was to propose methods to calculate the minimal length of the intestinal reversed loop taking into consideration the two previous conditions. Intestinal electromyograms were recorded in 65 rats at short-term (4 days after surgery) and ten rats at long-term (50 days after surgery). Control rats demonstrated that the preprandial regular spiking activity (RSA) of the migrating myoelectrical complex (MMC) extended simultaneously a definite part of the intestine which corresponds to the minimal length to reverse. A similar result can be obtained from a trigonometric representation. Whatever the method, the minimal lengths allowing the recording of RSA decreased along the rat intestine from 6 cm (proximal jejunum) to 4 cm (distal ileum). The experiments demonstrated that shorter loops did not present the preprandial RSA. In conclusion, the minimal reversed length depends on intestinal electromyographic parameters and, thereby, on the intestinal level.

The utility of traditional prehospital interventions in maintaining thermostasis

OBJECTIVE

Hypothermia can have a negative effect on the metabolic and hemostatic functions of patients with traumatic injuries. Multiple methods of rewarming are currently used in the prehospital arena, but little objective evidence for their effectiveness in this setting exists. The purpose of this study was to assess the relative effectiveness of traditional prehospital measures in maintaining thermostasis in trauma patients.

METHODS

Participating helicopter and ground ambulance ALS units were prospectively randomized to provide either routine care only (passive or no warming) or routine care (passive warming) in conjunction with active warming (either reflective blankets, hot pack rewarming, or warmed IV fluids). A total of 174 trauma code patients, aged >14 years, who met inclusion criteria were prospectively enrolled by prehospital providers. Patients who received a non-assigned intervention or who had incomplete temperature data were dropped from the analysis. A total of 134 patients were included in the final analysis.

RESULTS

Patients who received hot pack rewarming showed a mean increase in body temperature during transport (+1.36 degrees F/0.74 degrees C), while all other groups (no intervention, passive rewarming, reflective blankets, warmed IV fluids, warmed IV fluid plus reflective blanket) showed a mean decrease in temperature during transport [-0.34 to -0.61 degrees F (-0.2 to -0.4 degrees C); p<0.01]. In addition, the hot pack group was consistent, with every patient who received hot pack warming showing an increase in body temperature during transport, while in all other groups there were patients who had both increases and decreases in temperature. The intervention groups did not differ significantly on exposure to precipitation, transport unit temperature, total prehospital time, initial vital signs, amount of fluid administered, Injury Severity Score, or Glasgow Coma Score.

CONCLUSIONS

Most traditional methods of maintaining trauma patient temperature during prehospital transport appear to be inadequate. Aggressive use of hot packs, a simple, inexpensive intervention to maintain thermostasis, deserves further study as a potential basic intervention for trauma patients.

Documenting the scholarship of clinical teaching through peer review

The essence of teaching is to make a positive difference in the lives of students. To this end, the nursing department at Kent State University developed and implemented a faculty-driven, voluntary program for peer review of clinical teaching. The authors describe the clinical peer review program and its positive outcomes.

Peripheral neurotensin participates in the modulation of pre- and postprandial intestinal motility in rats

The present study was undertaken to determine whether neurotensin is involved in the regulation of the intestinal postprandial motor response and, if so, whether the regulatory pathway depends upon peripheral or central neurotensin secretion. Neurotensin, injected by the i.v. route (5 micrograms/kg) during the fasting state, induced firstly an increased irregular spiking activity during 30-40 min. This effect was followed by an increase of frequency of the myoelectrical complexes during 60 min. When injected by the i.c.v. route, neurotensin (0.5 microgram/kg) reinforced the fasting motility pattern of the small intestine after a latency of 70 min. Neurotensin was ineffective on the colon. The neurotensin receptor antagonist SR 48692 (200 micrograms/kg i.v.) reduced the duration of the postprandial motor response of the small intestine and blocked the late postprandial phase on the proximal colon while it suppressed the early postprandial phase on the distal colon. When administered i.c.v. (20 micrograms/kg), SR 48692 had no effect. It is concluded that neurotensin modulates intestinal postprandial motility essentially by a peripheral regulatory pathway. Endogenous neurotensin is involved in the maintenance of the postprandial motility pattern on the small intestine and the proximal colon while it is involved in the initiation of this response on the distal colon. This suggests that endogenous neurotensin acts via both endocrine and nervous mechanisms.

Hormone replacement therapy in a risk-benefit perspective

The relative cost-effectiveness of different treatment strategies for hormone replacement therapy (HRT) was assessed within the framework of a computer model. Where data were lacking, it was necessary to make assumptions about the effects of HRT, particularly in relation to combined oestrogen-progestogen therapy and cardiovascular disease; however, sensitivity analyses were performed to assess the impact of changing these assumptions on the cost-effectiveness equation. It appears that net expenditure by the NHS will depend critically on the direct costs of treatment, rather than on any indirect costs incurred or saved as a result of side-effects. In terms of mortality, a reduction in cardiovascular disease risk would have greatest impact and would overshadow any small increase in breast cancer risk which may be associated with long-term use. If the cardioprotective effect of oestrogen is real, our results suggest that long-term prophylactic treatment of hysterectomised women would be relatively cost-effective. Treatment of symptomatic menopausal women for any period of time appears to offer very good value for money. The lack of data relating to combined oestrogen-progestogen therapy and cardioprotection, and the major importance of the latter in the equation of benefits and risks, make it more difficult to draw conclusions about the cost-effectiveness of treating non-hysterectomised asymptomatic women for prophylactic reasons.

Age and experimental obstructive emphysema. A morphometrical study on the rat

Age, as a risk factor in the development of experimental obstructive emphysema, is proposed as the hypothesis of this study. Ninety-two Wistar rats were organized into two age groups: adult (16 weeks) and middle-aged (56 weeks). Each age group was subdivided into three groups: a control group, consisting of unmanipulated animals; a "cannula" group consisting of animals into whose trachea a cannula was implanted; and a "valve" group, consisting of animals into whose trachea a valve had been implanted. The survival was one month. A histomorphometric study was performed on the lungs and the results were compared statistically. Throughout the experiment the amount of food consumed by each animal and the variations in weight were monitored. After sacrifice, the lungs were processed for light microscopy. Thirteen histomorphometric variables were quantified and subsequently systematized into three groups: those which quantified the size of the distal airspace ("area of the alveolar section", "alveolar chord" and "mean linear intercept"): those which quantified the tissue ("wall thickness", "tissue density", "internal perimeter of each alveolar section", "internal alveolar perimeter per field" and "alveolar section/section perimeter"); and those which quantified the elastic fibre ("elastic fibre area", "elastic fibre perimeter", "elastic fibre area/elastic fibre perimeter", "elastic fibre density" and "elastic fibre density per tissue density"). The results were compared statistically and the sensitivity, specificity and misclassification indices were calculated, as well as the attributable and relative risk. From the results, it was observed that, in general, the animals of the valve and cannula groups in both age groups displayed a decrease in food intake and a body weight loss. The middle-aged animals were the only group which displayed significant differences in all the morphometric variables except wall thickness, when the cannula and valve groups were compared with the control group. In both the cannula and valve groups, the values of the variables which quantified the distal airspace increased, while the values of the variables which quantified the lung tissue and the elastic fibre decreased. In the manipulated middle-aged group, the attributable risk of developing emphysema was 56.66% and the relative risk 5.55; in the group of manipulated adult animals, the attributable risk was 23.55% and the relative risk 1.66. The results of this study lead us to propose that the middle-aged rats with experimental airflow obstruction displayed a greater risk of developing emphysema than the adult rats which were subjected to the same procedure.

A microtiter plate assay for measurement of serum alanine aminotransferase in blood donors

BACKGROUND

Alanine aminotransferase (ALT) testing in blood donors is required in many countries as a surrogate test for viral hepatitis. Current automated ALT assays do not fulfill some operational requirements of blood banks.

STUDY DESIGN AND METHODS

The standard ALT measurement method of the International Federation of Clinical Chemistry was adapted to the 96-well microtiter plate to obtain optimal conditions. The method was compared with a reference biochemical method using an analyzer on 251 serum samples.

RESULTS

The analytical variability was minimal (2.3% for an ALT level of 59 IU/L and 3.6% for an ALT level of 33 IU/L) after a total analysis time of 8 minutes and a time of 7 minutes before the first reading. With these measures, a linear standard curve was obtained in the range of 10 to 130 IU per L.A computerized validation procedure allowed rejection of samples with high ALT levels. Comparison with the analyzer gave a correlation coefficient, r = 0.935. The method proved to be efficient and time-saving in routine use over an 8-month period.

CONCLUSION

The microtiter plate ALT assay is helpful in allowing the simultaneous distribution of ALT and immunoenzymatic assays. It provides accurate results and a minimal risk of false-negative results.

Hypothyroidism increases TRH and TRH precursor levels in rat anterior pituitary

Thyroliberin (TRH) has been reported to be synthesized in anterior pituitary. Modulations of anterior pituitary concentrations of TRH and its precursor (proTRH) were investigated in rats rendered hypothyroid for 21 and 48 days. In hypothyroid rats, as expected, plasma TSH levels were increased and plasma free T4 concentrations were reduced, whereas anterior pituitary concentrations of TRH were markedly increased (mean +/- SEM fmol/mg protein, 106.9 +/- 21.1 at 21 days and 181.8 +/- 59.0 at 48 days vs 42.2 +/- 13.4 in controls). Significant increases of proTRH concentrations were found in hypothyroid rats (mean +/- SEM fmol/mg protein, 266.5 +/- 16.7 at 21 days and 320.4 +/- 51.1 at 48 days vs 214.1 +/- 18.3 in controls). Daily administration of L-T4 for the last week of PTU treatment (days 41 to 48) reversed hypothyroidism by lowering plasma TSH levels and by increasing plasma free T4 concentrations. Concomitantly, T4 administration significantly decreased anterior pituitary TRH contents (114.4 +/- 35.9) as well as proTRH contents (250.4 +/- 11.7). The fact that hypothyroidism regulates anterior pituitary TRH and proTRH contents strengthens the view that TRH might play a role in local regulatory mechanisms within the anterior pituitary on the thyrotropic function.

Effect of the slow-release formulation of somatuline (BIM 23014) on estrogen-induced hyperprolactinemia and lactotroph hyperplasia in the female rat

Somatuline, in common with other SRIH analogues, exerts antiproliferative and antisecretory activities on various tumors. Our purpose was to test the effectiveness of a slow-release formulation of somatuline on lactotroph hyperplasia and PRL hypersecretion induced by estrogens (17 beta E2) in rats. Female rats were primed with 17 beta E2 for 6 weeks before receiving somatuline (2 mg/kg) intramuscular injections every 10 days for one month. The mean anterior pituitary weight was 11.22 +/- 0.32 mg (mean +/- SEM) in non-estrogenized rats, 29.62 +/- 1.63 mg in 17 beta E2-primed rats and 23.58 +/- 1.26 mg in 17 beta E2-primed somatuline-treated rats. Mean plasma PRL level was 5.63 +/- 0.97 ng/ml, 182.37 +/- 27.55 ng/ml and 113.89 +/- 15.07 ng/ml in the same groups respectively. Thus, the 17 beta E2-induced pituitary enlargement and hyperprolactinemia were 20% and 38% lower respectively when animals were treated with somatuline during the last month of estrogenization. The 17 beta E2-induced increase in PRL cell density was also reduced by somatuline treatment. We conclude that the slow-release formulation of somatuline impedes 17 beta E2-induced hyperprolactinemia and pituitary enlargement concomittantly, at least in part by acting on lactotroph proliferation.

A possible interaction between serotonin and cholecystokinin-8 in the ileo-colonic motor responses to feeding in rats

The effects of cholecystokinin (CCK)-A, CCK-B, and 5-hydroxytryptamine-2 (5-HT2) receptor antagonists on the postprandial myoelectric activity of the ileum and the proximal and distal colon in rats were studied. After L364,718, a CCK-A receptor antagonist, or ritanserin, 5-HT2 receptor antagonist, the duration of the ileal postprandial motor pattern was reduced by 60%. In contrast, L365,260, a CCK-B receptor antagonist, had no effect. In the distal colon, the postprandial response was inhibited by CCK-A, CCK-B, and 5-HT2 receptor antagonists, whereas they were inactive in the proximal colon. CCK-8 administered at the end of the meal suppressed the inhibitory effect of ritanserin on the ileum and the distal colon. These results suggest that, in rats, CCK-8 is involved in the control of the ileal motor response to feeding through CCK-A receptors and in that of the distal colon through both CCK-A and CCK-B receptors. Serotonin seems to play a role in CCK-8 control through 5-HT2 receptors.

Measuring the impact of menopausal symptoms on quality of life

OBJECTIVE

To examine the impact of menopausal symptoms on the overall quality of life of women.

DESIGN

Data collection with a questionnaire administered by an interviewer, incorporating two different quality of life measurement techniques (time trade off and rating scale).

SETTING

Specialist menopause clinic and two general practices in Oxford.

SUBJECTS

63 women aged 45-60 years recruited opportunistically during a clinic or appointment with a general practitioner; no exclusion criteria.

RESULTS

Subjects gave very low quality of life ratings for health states with menopausal symptoms. The time trade off method of measuring preferences for these health states (on a scale from 0 to 1, where preference for full health is given as 1) yielded utility values of 0.64 for severe menopausal symptoms and 0.85 for mild symptoms. The rating scale measurement technique yielded even lower values: utilities of 0.30 and 0.65 were obtained for severe and mild symptoms respectively. Kappa scores indicated that the two methods produced results that were poorly related but not contradictory. Comparison of quality of life ratings before and after treatment with hormone replacement therapy showed significant improvements: with the rating scale measurement technique mean increases in utility values after the relief of severe and mild menopausal symptoms were 0.56 and 0.18 respectively.

CONCLUSIONS

Quality of life may be severely compromised in women with menopausal symptoms, and perceived improvements in quality of life in users of hormone replacement therapy seem to be substantial. This emphasises the need to include quality of life measurements when assessing outcomes of hormone replacement therapy. Several limitations may exist with widely applied measurement techniques, calling for the development of appropriate and well validated instruments for measuring quality of life associated with reduced health states.

An economic appraisal of alternative pre-natal screening programmes for Down's syndrome

The objective of this study was to evaluate economically a screening programme within the Oxford Regional Health Authority for Down's syndrome, based on maternal serum alpha fetoprotein, unconjugated oestriol and human chorionic gonadotrophin as well as maternal age (the triple test) against maternal age alone. The design of the study involved cost-effectiveness analysis of the triple test relative to the maternal age screening programme, and the main outcome measure was the cost per Down's birth avoided. It was found that the triple test is more cost-effective over a wide range of assumptions concerning detection rates and procedure costs. Indirect costs are important in considering the cost-effectiveness of the screening programmes. The most efficient detection rate is around 58 per cent for which the cost per Down's birth avoided is approximately 29,600 pounds if only direct costs are evaluated, 20,100 pounds if all NHS costs are considered and -49,800 pounds if all resource consequences are analysed. It may be concluded that screening for Down's syndrome using the triple test is cost-effective over a wide range of assumptions concerning detection rate and procedure costs. If all resource costs are considered, the programme is highly cost-effective in comparison with other health care interventions.

Action of enkephalinase (EC 3.4.24.11) inhibition on the pre- and post-prandial electromyographic patterns of colon in rats

Endogenous opioids are an important regulatory factor for the digestive tract and specially for its motility pattern. Enkephalin degradation includes an enkephalinase (EC 3.4.24. 11) and the effects on the colic electromyographic profile of its inhibition by acetorphan has been investigated in the unrestrained rat. Electromyogram consisted of Long Spike Bursts (LSB). In fasted state, they propagated indifferently in both aboral or oral directions from any point of the colon. Feeding privileges LSB which start near the cecal junction and propagated aborally to the distal colon. The acetorphan treatment (A) increases the percentage of LSB propagating aborally on the entire colon in fasted state and (B) reinforces the increased percentage of LSB which propagated down on the entire colon induced by feeding. All the actions of acetorphan on colic motility pattern disappear after inhibition of opioid receptors by naloxone. That may account for involvement of enkephalins in acetorphan properties on the pattern of the colic electrical activity.

Effect of some gastrointestinal hormones on motor and electrical activity of the digestive tract in the conscious cat

Three peptides structurally related to gastrin and known to be full agonists of antral motility in the conscious cat, pentagastrin (PG), cholecystokinin (CCK) and synthetic octapeptide of cholecystokinin (OP-CCK), were compared in relation to antral and duodenal electrical activity. They induced the same antral effect in eliciting an increase in the basal electrical rhythm (BER) and a short-lasting decrease in the frequency of the bursts of spikes. The electrical changes were correlated with lumen pressure changes measured in parallel, consisting of a decrease in the frequency of high-amplitude peaks and an increase in low-amplitude peaks. The additive effect of PG and CCK shows that the peptides are full agonists for antral electrical activity, as they are for antral motility and acid secretion. In contrast to the antrum, the three peptides increased the frequency of the duodenal spike bursts, CCK and OP-CCK decreased the BER frequency, while PG increased BER slightly. The increase in antral and duodenal BER obtained after a beef-liver meal, which produced a large endogenous gastrin release, suggests a major role for gastrin in antral motility induced by feeding, at least in the cat.

Further studies on proteinases and alpha 2-macroglobulin activity in diabetic plasma

Loss of chymotrypsin binding capacity of alpha 2-macroglobulin in diabetic plasma on in vitro incubation, could be partially prevented by phenylmethyl sulphonyl fluoride and pepstatin A. Prior ten-fold dilution of plasma with 0.02 M phosphate buffer (pH 7.0) completely arrested the process. The phenomenon could not be reactivated by Ca2+, lecithin or bovine serum albumin. Diabetic plasma, like normal plasma, exhibited maximal hydrolytic activities on H-D-Pro-Phe-Arg-p-nitroanilide, H-D-Val-Leu-Arg-p-nitroanilide and H-D-Ile-Pro-Arg-p-nitroanilide. The hydrolytic activities were not significantly diminished on incubation of plasma at 37 degrees C for 12 hr, unlike alpha 2-macroglobulin activity. On gel chromatography on Sephadex G-200, part of the proteolytic activity in diabetic plasma coeluted with alpha 2-macroglobulin in the VO region. A second activity peak (absent in normal plasma) was eluted with a Ve/V0 value of 1.40. Possible role of free proteinases in diabetic plasma in the inactivation of alpha 2-macroglobulin is discussed.

HRT: an analysis of benefits, risks and costs

A cost-effectiveness analysis of hormone replacement therapy (HRT) was undertaken to assess the relative benefits of different treatment strategies, and to identify which factors most influence cost-effectiveness. The current lack of conclusive evidence on the effects of HRT, especially in relation to combined therapy and cardiovascular disease, necessitated the use of a large number of assumptions in our model. In terms of net health benefits, the potential reduction in cardiovascular disease would have greatest impact, and would overshadow any small increase in breast cancer risk possibly associated with long-term use. Net expenditure by the NHS will depend critically on the direct costs of treatment, rather than on any indirect costs incurred or averted as a result of side-effects. In terms of cost-effectiveness, long-term prophylactic treatment of hysterectomised women and treatment of symptomatic women with a uterus compare favourably with other accepted health care interventions.

[Physico-chemical properties of 4 endodontic sealing cements]

Four endodontic sealers were compared with two series of tests, in thin layer and in 10 mm long and 5 mm diameter rods. Under these conditions, the Pulp Canal Sealer showed the best ability to present a thin layer and the same flow than the Cortisomol. Its setting time was 15 minutes. Forty-eight hours later, the Sealite showed a very good tightness compared to the other sealers. At 30 days, the Pulp Canal Sealer and the OZn-Eugénol were the tightest ones. Less water was absorbed with the Cortisomal and the Sealite. Is there, for these sealers, any correlation between water-absorbtion and tightness?

A radioautographic comparison of in vivo 3H-proline and 3H-serine incorporation in the pulpal dentine of rat molars: variations according to the different zones

3H proline and 3H serine were injected intraperitoneally to rats which were killed 4 and 24 hours later. The incorporation of the labelled precursors was studied in the odontoblasts, predentine and dentine of the first lower molars. After radioautography, statistically significant differences in grain density appeared between the furcation, occlusal and lateral areas of the pulp chamber. The incorporation of predentine components into dentine was faster in the lateral than in the occlusal area, the slowest being detected in the furcation area. These differences may be related to the distribution of occlusal forces in the rat molar.