Brain function and effects of shift work: implications for clinical neuropharmacology

Night or shift work is to a relevant extent unavoidable, suits a growing preference for flexibility and is predicted to spread. However, a significant percentage of shift workers report discomfort or health problems and they often (15-20% of cases) move to different occupations. Apart from social implications, the issue has medical and scientific relevance, with evidence suggesting that the circadian rhythm phases are neither equivalent nor interchangeable with respect to function and performance. Shift work may affect the gastrointestinal and cardiovascular functions, alter the hormonal and sleepiness cycles, favor sleep disturbances of medical relevance, interfere with behavior and social life and increase the risk of accidents (e.g. road accidents). The implications for clinical (neuro)pharmacology are relevant and, in several instances, critical. Shift work can interfere with mechanisms regulating drug kinetics in peripheral compartments and action at selective brain sites, either directly or through effects on the gastrointestinal/hormonal cycles. In this paper, the relevant literature is reviewed and original data on the effects of shift work are reported. Basic and clinical research should take into account the possible effects on drug action of an active life and working schedule in inappropriate phases of the circadian cycles and the risk of inadequate drug dosing or unexpected abnormal action in subjects under long-term or chronic treatment. A scientific approach, action by the scientific community involved in pharmacological research and monitoring by the regulating agencies are advisable. Regulation may help reduce the medical and social impact and improve quality of life.

Health conditions of bus drivers in a 6 year follow up study

The bus drivers of a public bus company, working in a fast rotating 4 shift system from 05.00 to 24.30, were examined in 1993 (230 persons) and 1999 (266 persons). The comparison between the two years showed no significant differences for all the parameters evaluated by the Standard Shiftwork Index and medical examination. In both surveys work organisation was considered "efficient-fairly good" by most workers, who were mostly satisfied with their job. Work load was rated significantly higher for "afternoon" and "morning" shifts, during which most accidents at work and "in itinere" occurred. Night sleep was reduced by 3 hours on "early" shift and about 2 hours on "morning" shifts. The most prevalent health troubles dealt with low back pain, gastritis, headache and haemorrhoids. Neuroticism was the trait more correlated with poorer health conditions, whereas shiftwork exposure appeared as a significant predictor of risk of critical Effort/Reward Imbalance and minor psychological disorders. Both extrinsic and intrinsic efforts significantly increased with age, but not reward. The comparison of the same cohort of 108 persons examined both in 1993 and in 1999 showed a significant increase of low back pain, gastrointestinal troubles, haemorrhoids and lipids disorders.

Dissection of the HLA association with multiple sclerosis in the founder isolated population of Sardinia

Several studies have indicated that multiple sclerosis (MS) is associated and linked to the major histocompatibility complex (MHC)/human leukocyte antigen (HLA) region of chromosome 6p21.3, but the exact location and nature of the primarily associated locus within the HLA complex is still controversial and largely presumptive. By linkage disequilibrium mapping, we have systematically investigated this chromosome region in the founder population of Sardinia to determine the relative associations of the various loci with MS. An overall 11.4 Mb region, which encompasses the whole HLA complex, was scanned with 19 microsatellite markers and with single nucleotide polymorphisms within 12 functional candidate genes and assessed for MS association using the extended transmission disequilibrium test (ETDT). A peak of association represented by the three adjacent DRB1, -DQA1 and -DQB1 loci was detected in the class II region. Two additional less significant areas of association were detected, respectively, in the centromeric side of the class II region at the DPB1 locus and, telomeric of the classically defined class I loci, at the D6S1683 microsatellite. Conditional ETDT analysis indicated that these regions of association could be independent of each other. Within the main peak of association, DRB1 and DQB1 contribute to the disease association independently of each other whereas DQA1 had no detectable primary genetic effects. We evaluated the haplotype distribution at the region showing the strongest association and found five DQB1-DRB1 haplotypes positively associated with MS in Sardinia. These consistently included all the haplotypes previously found associated with MS in the various human populations, thus supporting a primary effect of the products of these loci in MS. Overall these results are consistent with a multilocus model of the MHC encoded susceptibility to MS.

The 24-hour society between myth and reality

The 24-hour society appears to be an ineluctable process towards a social organisation where time constraints are no more "restricting" the human life. But, what kind of 24-hour society do we need? At what costs? Are they acceptable/sustainable? Shift work, night work, irregular and flexible working hours, together with new technologies, are the milestone of this epochal passage, of which shift workers are builders and victims at the same time. The borders between working and social times are no more fixed and rigidly determined: not only the link between work place and working hours is broken, but also the value of working time changes according to the different economic/productive/social effects it can make. What are the advantages and disadvantages for the individual, the companies, and the society? What is the cost/benefit ratio in terms of physical health; psychological well-being, family and social life? The research on irregular working hours and health shows us what can be the negative consequences of non-human-centered working times organisations. Coping properly with this process means avoiding a passive acceptance of it with consequent maladjustments at both individual and social level, but adopting effective preventive and compensative strategies aimed at building a more sustainable society, at acceptable costs and with the highest possible benefits.

Nitrergic relaxation in urethral smooth muscle: involvement of potassium channels and alternative redox forms of NO

We examined the contribution of K+ channels to the relaxation responses induced by different redox forms of nitric oxide (NO., NO- and NO+) in comparison with those evoked by electrical field stimulation (EFS) of nitrergic nerves in the sheep urethra. K+ channel blockers with different selectivity profile were used. Sodium nitroprusside (SNP) and different S-nitrosothiols were used as NO+ donors, Angeli's salt as an NO- donor and nitroglycerin (GTN) was chosen as a representative compound known to require metabolic activation in the target tissue. Pure NO gas was used to prepare NO. solutions. Relaxation evoked by EFS of nitrergic nerves or by exogenous NO was not inhibited by any of the K+ channel blockers, but was enhanced by 4-aminopyridine [inhibitor of voltage-dependent K+ (KV) channels]. This suggests that, whereas K+ channel activation and hyperpolarization of the postsynaptic membrane do not contribute to relaxation, prejunctional modulation of the nitrergic neurotransmission by Kv channels may be relevant. Relaxation induced by NO+ or NO- donors was not affected by K+ channel blockade with the following exceptions: glybenclamide, a blocker of ATP-sensitive K+ channels (KATP), enhanced responses to SNP and Angeli's salt, 4-aminopyridine inhibited relaxation evoked by Angeli's salt and GTN, and charybdotoxin, a blocker of large-conductance, Ca2+-activated K+ channels (BKCa) inhibited those induced by the S-nitrosothiol S-nitrosoglutathione. These results do not suggest the existence of a general mechanism of action on K+ channels for compounds releasing either NO+ or NO- in the sheep urethra. None of the K+ channel blockers affected relaxation induced by the membrane-permeable analogue of cGMP, 8-bromo-cGMP. However, the fact that the addition of the phosphodiesterase inhibitor zaprinast (0.1 mM) enhanced the relaxation to Angeli's salt, while preventing the inhibition induced by 4-aminopyridine, suggests that involvement of guanylate cyclase activation in the action of NO donors on K+ channels can not be excluded. Accordingly, the guanylate cyclase inhibitors 1H-[1,2,4]-oxadiazole-[4,3-a]-quinoxalin-1-one (ODQ, 10 microM) and 4H-8-bromo-1,2,4-oxadiazolo(3,4-d)benz(b)(1,4)oxazin-1-one (NS 2028, 10 microM) almost abolished relaxations to EFS and Angeli's salt. In contrast, ODQ only moderately inhibited relaxations to NO.. In addition, the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl imidazoline-1-oxyl 3-oxide (carboxy-PTIO) effectively inhibited responses to NO. whilst not affecting those to EFS or NO-, suggesting a close similarity between the nitrergic transmitter and nitroxyl ion. We conclude that nitrergic relaxation induced either by the endogenous transmitter or by exogenous NO donors in the ovine urethra is not mediated by postsynaptic alterations in the K+ conductance; only a prejunctional modulation through Kv channels seems to be significant. In addition, the production and/or release of alternative redox forms of NO, such as NO-, may be involved in neurotransmission processes in the urethra.

The effect of a change in sleep-wakefulness timing, bright light and physical exercise interventions on 24-hour patterns of performance, mood and body temperature

Experiments consisting of baseline, bright light and physical exercise studies were carried out to compare the effect of a 9-hour delay in sleep-wakefulness timing, and the effects of bright light and physical exercise interventions on 24-hour patterns of performance, mood and body temperature were examined. Each study comprised a 24-hour constant routine at the beginning followed by 3 night shifts and 24-hour constant routine at the end. Performance on tasks differing in cognitive load, mood and body temperature was measured during each constant routine and the interventions were applied during the night shifts. The 24-hour pattern of alertness and performance on the tasks with low cognitive load in post-treatment conditions followed the change in sleep-wakefulness timing while more cognitively loaded tasks tended to show a reverse trend when compared to pre-treatment conditions. There was a phase delay around 4 hours in circadian rhythms of body temperature in post-treatment conditions.

Flexible work hours, health and well-being in the European Union: preliminary data from a SALTSA project

Demand for flexible work hours (FWH) is increasing in Europe aimed at increasing the number of production hours on one hand, and, on the other, reducing individual working hours and/or increasing autonomy and control on them. In view of the lack of knowledge of the effects of FWH on health and safety, we started a pilot project, funded by the Joint Programme for Working Life Research in Europe (SALTSA), aimed at: a) comparing the most relevant national legislation and how the EU Directive 93/104 "concerning certain aspects of working time" has been implemented in the member States; b) reporting prevalence and trend of FWH in Europe according to the three EU Surveys on Working Conditions carried out in the last decade; c) collecting practical examples of innovative FWH; d) evaluating their impact on health and safety in relation to work sectors, job demands, social life, aging and gender. Consequent actions are going to include information and consultancy for pertinent authorities and social parties involved, as well as training programmes for Union officials and similar groups concerning the organisation of FWH according to ergonomic principles.

Subjective effects of AMPT-induced dopamine depletion in schizophrenia: correlation between dysphoric responses and striatal D(2) binding ratios on SPECT imaging

Approximately one third of schizophrenic patients treated with neuroleptic drugs experience unpleasant subjective responses, that are collectively known as neuroleptic dysphoria. Experimental research in animals indicates that drug induced dopaminergic blockade in mesolimbic circuits, especially the nucleus accumbens, leads to impaired pleasure responsivity and dysphoria. The present study tested this putative mechanism in drug-free schizophrenic patients (n = 12), through inducing dysphoric responses with alphamethyl paratyrosine (AMPT) and simultaneously quantifying their baseline striatal dopmine (D(2)) function with (123)IBZM-SPECT imaging. Results showed a wide variability in the occurrence and severity of dysphoric responses, clearly distinguishing a dysphoric group from non-dysphoric responders. Severity of dysphoric responses, measured by standardized rating scales, correlated inversely with changes in D(2) receptor binding ratios (r = +0.82, p <.01). These results support the notion that striatal dopaminergic activity is not uniformly elevated in all schizophrenic patients, and the sub-group of individuals with lower baseline dopamine function are at an increased risk for dysphoric responses during antipsychotic therapy with dopaminergic blocking drugs.

[Ambulatory closed surgery for the treatment of pilonidal sinus]

Pilonidal disease (PD) is a common chronic disorder of the sacrococcygeal region afflecting young people. Despite several methods for treating PD have been described, the management remains controversial. Recent reports have advocated different surgical approaches such as open or closed technique, but recurrence plagues all forms of therapy. We conducted this case review to evaluate the validity of an outpatient closed technique in the treatment of chronic pilonidal disease. Between January 1997 and July 1999, 65 consecutive patients with quiescent chronic PD were electively treated by surgical excision of the cyst and primary closure. There were 47 men (72%) and 18 women (28%) in this study. Patients ranged in age from 14 to 47 years, the average age being 21 years. The median healing time was 8 days and the median time to return to full work was 20 days (range 10-25). Infection and recurrence rates were 1.5% and 4.6% respectively. There was no correlation among recurrence rate, postoperative infection, or prior surgery. Cyst excision and primary closure is a safe, low cost operation with a very high long-term success rate and a negligible rate of complications. It can successfully be performed under local anaesthesia in an outpatient facility.

Clinical significance of normobasemia in early post-operative outcome of hepatic resections

BACKGROUND

Major hepatic resections are usually followed by acid-base unbalance. Adjustment of the acid-base disorders is considered central when dealing with these critical patients and normobasemia is thought to be a favourable prognostic factor when occurring in the immediate postoperative outcome after major surgery. The present study was undertaken to investigate the influence of acid base balance on the early outcome after hepatic resection.

METHODS

A series of fifty-seven cirrhotic patients was submitted to liver resection for hepatocellular carcinoma. Forty-eight patients experienced an uneventful early postoperative outcome (CTR group). Nine died in the postoperative course (HD group). In all patients pulmonary, renal and hepatic functions were monitored pre- and postoperatively. The pH values were detected daily preoperatively and in the course of the first three days after hepatic resection. In the same days acid base balance and arterial ketone body ratio were assessed on arterial blood samples. Data were collected in a data base and statistical analysis was performed.

RESULTS

A significantly higher metabolic alkalosis was found to characterize the first and second postoperative days (POD1 and POD2) in the CTR group (pH 7.43+/-0.007 vs pH 7.33+/-0.001; pH 7.45+/-0.006 vs pH 7.35+/-0.009; p<0.05). Lower values of pH and an associated impaired energetic status of the liver were found to characterise the postoperative course of the poor prognosis patients. At POD1 AKBR decreased in both groups but while recovering at POD2 in patients of CTR group maintained significantly lower values in HD group (AKBR 1+/-0.3 vs 0.5+/-0.2; p<0.01). A lower energetic status of the liver is associated with an inadequate tricarboxylic acid cycle and is responsible for an impaired production of HCO3-.

CONCLUSIONS

Apparent normobasemia is then expressive of liver failure leading to poor postoperative outcome.

The influence of somatostatin on bacterial translocation

BACKGROUND

Bacterial translocation is defined as the passage of bacteria from the gastrointestinal tract to extraintestinal sites mostly as a consequence of the loss of the gut barrier function. Somatostatin and octreotide, exerting many inhibitory effects on the gastrointestinal tract, have been evidenced to promote bacterial translocation.

DESIGN

experimental research.

SETTING

University teaching Hospital.

INTERVENTIONS

Sixteen pigs forming the study group received 25 mg/kg of octreotide twice a day for ten days. A control group (n=16) received an equal volume of saline solution for the same period. All animals were sacrificed and tissue cultures were obtained from mesenteric lymph nodes (MLN), liver and spleen. Portal venous and central venous blood samples were also withdrawn for culture.

RESULTS

In the octreotide group, cultures were positive for bacteria in 43.7% (7/16) of animals. Viable bacteria were recovered from MLN, liver and spleen. Portal and systemic blood cultures showed no growth of bacteria. The mean value of bacterial detection in MLN, liver and spleen was 196+/-13 CFU/g, 190+/-26 CFU/g, and 173+/-0 CFU/g, respectively. P value was not statistically significant. Bacterial translocation did not occur in the animals of the control group. Fisher s exact test revealed a statistically significant difference (p<0.007) between the two groups regarding bacterial translocation to MLN.

CONCLUSIONS

The administration of octreotide is followed by a conspicuous increase in bacterial translocation in pigs. Further clinical studies are needed to demonstrate similar effects on humans.

Working and health conditions of Italian air traffic controllers

The paper summarises some studies carried out in recent years on Italian air traffic controllers. Work stress appeared related mainly to mental charge, aggravated by time pressure and high responsibility. Shiftwork was not considered highly stressful, thanks to the good shift schedules adopted. The disorders most frequently complained of had a prevalent psychosomatic component, concerning the digestive, neuropsychic, and cardiovascular systems. However, their prevalence was lower than, or similar to, that recorded in general population. The controllers engaged in regional centres showed slightly worse health conditions than those engaged in airport towers; the same was found in the radar controllers compared to those working in non-radar positions.

Total mesorectal excision and low rectal anastomosis for the treatment of rectal cancer and prevention of pelvic recurrences

HYPOTHESIS

Total mesorectal excision lowers the rate of pelvic recurrence and positively affects the survival after surgical treatment of rectal cancer.

DESIGN

Case series.

SETTING

Tertiary care university hospital.

PATIENTS

Fifty-three consecutive patients were admitted with curative intent to surgery at the First Department of Surgery of the University of Rome "La Sapienza," Rome, Italy, with diagnoses of rectal carcinoma. The mean follow-up was 68.9 months; follow-up was complete for all patients who entered the trial.

INTERVENTIONS

Low anterior resection and total mesorectal excision were performed in all cases, regardless of the location of the rectal cancer. A straight mechanical colorectal anastomosis was performed on a rectal stump, never exceeding 5 cm. No kind of adjuvant therapy was given. Mesorectum and open rectum were studied by serial transverse section at 5-mm intervals. A search for depth of penetration and distal intramural extension of the tumor was made. Lymph nodes were detected by clearing method, and nodal metastases (NM) and nonnodal metastases (NNM) were recorded as situated proximally, distally, or at the level of the tumor.

RESULTS

There was no postoperative mortality. Clinical and radiologic leaks occurred in 2 and 4 patients, respectively. Mean disease-free survival was 65.9 months. Pelvic recurrence occurred in 5 patients (9%). Overall 5-year survival rate was 75%. Involvement of mesorectum by NM and NNM was detected in 27 and 24 cases, respectively. Both NM and NNM were found to be distal in 33% and 40% of cases, respectively.

CONCLUSIONS

Microscopic spread to the distal mesorectum may exceed the intramural spread of rectal cancer. Failure to perform total mesorectal excision leaves a potentially residual disease in the distal mesorectum, thus predisposing the patient to pelvic recurrence.

Halo structure of (14)Be

The two-neutron halo nucleus (14)Be has been investigated in a kinematically complete measurement of the fragments ((12)Be and neutrons) produced in dissociation at 35 MeV/nucleon on C and Pb targets. Two-neutron removal cross sections, neutron angular distributions, and invariant mass spectra were measured, and the contributions from electromagnetic dissociation (EMD) were deduced. Comparison with three-body model calculations suggests that the halo wave function contains a large nu(2s(1/2))(2) admixture. The EMD invariant mass spectrum exhibited enhanced strength near threshold consistent with a nonresonant soft-dipole excitation.

Nicotine prevents striatal dopamine loss produced by 6-hydroxydopamine lesion in the substantia nigra

While the work of several groups has shown the neuroprotective effects of nicotine in vitro, evidences for the same effects in vivo are controversial, mainly regarding neuroprotection in experimental models of Parkinson's disease. In this context, we investigated the capability of various systemic administration schedules of nicotine to prevent the loss of striatal dopamine levels produced by partial or extensive 6-hydroxydopamine (6-OHDA) lesion of rat substantia nigra (SN). Eight days after 6- and 10-microg injections of 6-OHDA in the SN there was a significant decrease of dopamine concentrations in the corpus striatum (CS) and a concomitant increase in dopamine turnover. While 10 microg 6-OHDA produced an almost complete depletion of dopamine in the SN, 6 microg decreased dopamine levels by 50%. Subcutaneous nicotine (1 mg/kg) administered 4 h before and 20, 44 and 68 h after 6 microg 6-OHDA, prevented significantly the striatal dopamine loss. Administered only 18 or 4 h before or only 20, 44 and 68 h after, nicotine failed to counteract the loss of dopamine or the increase in dopamine turnover observed in the CS. Nicotine also failed to prevent significantly the decrease of striatal dopamine levels produced by the 10-microg 6-OHDA intranigral dose. Chlorisondamine, a long-lasting nicotinic acetylcholine receptor antagonist, reverted significantly the nicotinic protective effects on dopamine concentrations. These results are showing that putative neuroprotective effects of nicotine in vivo depend on an acute intermittent administration schedule and on the extent of the brain lesion.

[Layered and mass sutures in the closure of median laparotomies]

A retrospective comparison of 2830 patients with midline abdominal incision closures was made. Dehiscences, infections, hernias were compared examining continuous mass closures (group A) versus interrupted mass closures (group B) and interrupted layered sutures (group C). The three groups were well matched for known risk factors for each of the above complications. Mass closures produced a significant higher number of infections (p = 0.0006) and hernias (p = 0.0001). There was no significant difference in the rate of dehiscences in the three suture groups (p = 0.07). A significant correlation was found in all three groups between the incidence of infections and that of outcoming incisional hernias. In the current study layered closure of the of the midline abdominal wounds yielded better results when compared with both running mass and interrupted mass closures. The knowledge of these findings might help when choosing the procedure to close a midline abdominal incision.

[Biphasic hypopharyngeal synovial sarcoma: ultrastructural, cytofluorometric and immunohistochemical study and brief review of the literature]

Synovial sarcomas account for 7-10% of all soft tissue malignancies and the rare head and neck region location accounts for an average 5% of them. A brief review of the data in the Literature has shown that not more than one hundred cases of cervical-facial synovial sarcoma have been reported. In the head and neck locations this form of tumor is significantly less aggressive, with a higher survival rate and a recurrence rate much lower than the 60-70% shown for other locations in the limbs. After a brief review of the Literature, Authors present a rare clinical case of hypopharyngeal synovial sarcoma which recently came under observation. Despite the accurate diagnostic procedure, after surgical removal of the tumor by CO2 laser microlaryngoscopy, diagnosis required the use of histological and ultrastructural techniques. CT and NMR of the neck using contrast medium showed that the structure of the neoformation was similar to that of the soft tissues, it was 3-4 cm in diameter, located in the hypopharynx and had an extensive surface in contact with the left glossoepiglottic groove. The lesion appeared to involve the free edge of the aryepiglottic fold, coming into contact with the free edge of the epiglottis; it could not be dissociated form the epiglottis and obliterated both the homolateral glossoepiglottic vallecula and the pyriform sinus. Structural analysis after radiography with a contrast medium showed a marked impregnation of the lesion, indicative of high degree of vascolarization. Ultrastructural, cytofluormetric and immunohistochemical analyses were performed on the neoplasm in order to process all these data together with the clinical parameters; in other words a multi-parameter evaluation was performed, as suggested by other Authors, to determine the therapy and arrange more accurate monitoring of this patient, victim of a neoplasm with a high potential for metastases.

Hepatotoxicity of camptothecin derivatives in a primary culture system of rat hepatocytes

The topoisomerase I inhibitors are a new class of antineoplastic agents currently under clinical development. Among these compounds there are some camptothecin (CPT) derivatives with improved toxicity profiles and antitumor activity: irinotecan (CPT-11) and topotecan (TPT), particularly active against colon, lung and ovarian cancer. The aim of this study was to evaluate the cytotoxicity of CPT, CPT-11, its metabolite SN38 and TPT in a primary culture system of rat hepatocytes. Cytotoxicity was evaluated by measuring the leakage of lactate dehydrogenase (LDH) into the medium and by assessing cell viability in terms of tetrazolium salts (MTT) reduction by mitochondrial dehydrogenase activity. Our results showed that cytotoxicity was limited in the case of short drug exposure. There was a significant and time-dependent increase in LDH leakage and a significant time- and dose-dependent decrease in MTT reduction after 3 h of incubation (p<0.01). In the treatments with doses related to peak plasma levels, CPT-11 was less responsible for the observed in vitro hepatotoxicity than its metabolite SN38; TPT had lower LDH leakage compared to SN38 and CPT-11 but showed significant and early (3 h) decrease in MTT reduction: this may mean a different mechanism of cellular damage. These results demonstrate that CPT derivatives are directly toxic to liver cells in a distinct time- and dose-related response.

[Work capacity and aging]

Maintaining a good work ability depends on satisfactory health and employment status, which is supported by suitable working conditions and correct life styles. From the biological perspective, ageing means a foreseeable progressive and overall deterioration of the various physiological systems, but not of such a kind and severity to consider most people over 50 as too old or unfit for work, as has been shown by several studies that assessed work ability not only in terms of biological age, but of functional age and actual work output. From the physio-pathological perspective, we can observe either illnesses associated with the passage of time or age-related changes that might precipitate diseases, as well as environmental changes that modulate ageing and developmental changes that accelerate or retard ageing. From the practical point of view, it should taken into account that job demands often do not follow the natural biological and functional changes of the individual, consequently the relative work load can be higher in older workers. On the other hand, ageing also means a professional growth in terms of strategic ability, shrewdness, wisdom and experience. The high interindividual variability of physical, mental and social conditions that is observed with the increase in age makes it necessary to adopt flexible and personally tailored measures, as shown by recent surveys in some European countries aimed at reducing age discrimination and work disability, and at promoting work ability by means of actions directed towards both improvement of work organisation and support of psycho-physical conditions of older workers.

[Aging of the working population in the European Union]

The working population over 50 years of age will grow considerably during the next 15 years. After 2010, the number of retired people over 65 years of age will be almost double that of 1995, with a strong impact also on working conditions and the labour market. Work ability is a dynamic process that changes, through its components, throughout life and is the result of the interaction between individual resources (including health, functional capacity, education and skills), working conditions, and the surrounding society. Work ability creates the basis for the employability of an individual, which can be supported by a number of actions (e.g. legislation on work and retirement) and social attitudes (e.g. age discrimination). Consequently, the prevalence of limitations in work ability varies significantly according to how it is evaluated and the frequency of work disability can vary considerably in different times, locations and populations. The Work Ability Index, created and used in a Finnish 11-year longitudinal study, has been proved a useful practical tool for the assessment of workers' fitness and a good predictor of work disability. Measures able to restore, maintain or promote work ability depend on the current work status and the needs of the target groups, and must concentrate on work content, physical work environment and the work community. The actions targeted towards the individual, on the other hand, concentrate on strengthening the health status and functional resources of the workers and developing professional expertise and skills. Correctly targeted and integrated measures improve work ability of ageing workers and therefore lead to improved work quality, increased productivity and also improved quality of life and well-being. They also have positive long-term effects on the "third age", when the worker retires.

Prospective evaluation of omentoplasty in preventing leakage of colorectal anastomosis

PURPOSE

The aim of this study was to investigate the role of omentoplasty, by means of intact omentum, in preventing anastomotic leakages after rectal resection.

METHODS

Between 1992 and 1997 a total of 112 patients (64 males) with a mean age of 64.7 (range, 39-83) years were randomly assigned to undergo omentoplasty (Group A) or not (Group B) to reinforce the colorectal anastomosis after anterior resection for rectal cancer. The primary end point was anastomotic leakage; the secondary end point included morbidity and mortality related to omentoplasty.

RESULTS

The two groups were comparable in terms of preoperative and intraoperative characteristics. Staple-ring disruption at plain abdominal radiographs was detected in seven instances in Group A and in ten in Group B patients (P = not significant). Two leakages were evident clinically in Group A and seven in Group B (P < 0.05). Three leaks were documented radiologically in Group A and eight in Group B (P = not significant). No complications related to omentoplasty were observed in Group A. There were two repeat operations for anastomotic leakage in Group B. At followup, one stricture developed in Group A and three in Group B (P = not significant)

CONCLUSIONS

Despite a similar incidence of staple-ring defects, a strikingly lower rate of clinically and radiologically detected leaks developed in patients submitted to omentoplasty. Although not affecting the incidence of anastomotic disruption, omentoplasty seems to contain the severity of anastomotic leakage.