Spinal fluid dynamics during thoracic- and thoracoabdominal aortic surgery.

AIM: The intention was to investigate cerebrospinal fluid pressure (CSFP) and volume of cerebrospinal fluid (CSF) drained during and after thoracic- and thoracoabdominal aneurysm repair. The findings were related to the occurrence of postoperative neurologic deficits. METHODS: Twenty-nine patients (12 with thoracic and 17 with thoracoabdominal aortic aneurysm) were operated without shunting or extracorporeal circulation. For monitoring of CSFP an intrathecal catheter was placed in all patients. The volume of CSF withdrawn intraoperatively, on the day of operation as well as on the 1st and 2nd postoperative day was recorded. RESULTS: Twenty-six patients had no postoperative neurologic sequelae. One patient had postoperative paraplegia while 2 had paraparesis. The three patients with neurologic sequelae had higher CSFP intraoperatively than those without neurologic symptoms (P=0.04). Median CSFP during aortic cross-clamping was 19 mmHg and 10 mmHg and the median volumes of CSF drained on the day of operation 210 and 85 mL in the two groups, respectively. There was a significant positive correlation between CSFP and central venous pressure. CONCLUSIONS: A higher intraoperative CSFP was observed in patients with neurologic sequelae following thoracic- and thoracoabdominal aneurysm repair. Further, there was a tendency of higher volumes of CSF drained in this group of patients. Although, the series is too small to allow firm conclusions, it supports the view that CSFP monitoring and drainage is beneficial during thoracic- and thoracoabdominal aneurysm repair.     

Somatosensory findings in patients with spinal cord injury and central dysaesthesia pain.

OBJECTIVE: To determine whether central pain in patients with spinal cord injury is only dependent on the lesioning of spinothalamic pathways. METHODS: In sixteen patients with spinal cord injury and central dysaesthesia pain, somatosensory abnormalities in painful denervated skin areas were compared with somatosensory findings in normal skin areas as well as in non-painful denervated skin areas. RESULTS: The threshold values for detection of thermal (heat, cold, heat pain, or cold pain) and tactile stimulation were significantly changed in denervated skin areas although there were no significant differences in the threshold values between painful and non-painful denervated skin areas. The reductions of sensations of touch, vibration, joint position, and two point discrimination in painful and non-painful denervated skin areas were not significantly different. Allodynia (pain caused by non-noxious stimulation) and wind up-like pain (pain caused by repeatedly pricking the skin) were significantly more common in painful than non-painful denervated skin areas. CONCLUSIONS: Because pain and thermal sensory perception are primarily mediated to the brain via spinothalamic pathways, whereas the sensations of touch, vibration and joint position are primarily mediated by dorsal column-medial lemniscal pathways, the results indicate that central pain is not only dependent on the lesioning of either dorsal column-medial lemniscal pathways or spinothalamic pathways. The findings of abnormal evoked pain (allodynia and wind up-like pain) may be consistent with the experimental findings of hyperexcitability in nociceptive spinothalamic tract neurons, that may be involved in the pathogenesis of central pain.     

Interactions between serotonin and substance P in the spinal regulation of nociception

Interactions between 5-hydroxytryptamine (5-HT) and substance P (SP) in the mouse spinal cord were investigated using the tail-flick test and the behavioral response evoked by intrathecal (i.th.) SP or i.th. 5-HT. I.th. injection of 5-HT (20 μg) or the 5-HT₁ receptor agonists(+)-8-hydroxy-2-(di-n-propylamino)tetralin ((+)-8-OH-DPAT) (20 μg) or 5-methoxy-3(1,2,3,6-tetrahydropyridine-4-yl)-1H-indole (RU 24969) (20 μg) markedly inhibited the tail-flick reflex. The effect of these compounds was reduced when SP (5 μg) was given i.th. 55 min, or 55 and 45 min before the agonists. The tail-flick latencies recorded 5 min before injection of a 5-HT agonist were similar in animals treated with SP or vehicle. The changes in the tail-flick test were not due to changes in tail skin temperature since only minimal differences in the skin temperature were recorded between the groups injected with SP or vehicle. I.th. injection of SP (10 ng) or 5-HT (2 μg) produced a similar behavioral response consisting of biting, licking and scratching of the caudal part of the body, indicative of nociceptive stimulation. The responses both to i.th. SP and 5-HT were reduced after i.th. application of SP receptor antagonist [d-Arg¹,d-Trp^7,9,Leu¹¹]-SP (Spantide) (5 μg), as well as 5 min after i.th. injection of the 5-HT receptor antagonist metergoline (4 μg). The data may indicate functional interactions between SP and 5-HT in the mouse spinal cord, which may take place in neurons involved in the processing of nociception.     

Treatment of stomach cancer, a national experience

A total of 1165 patients with stomach cancer were entered into a prospective, observational national study. They represented 54 per cent of all stomach cancer patients reported to the Cancer Registry in Norway during the study period, and data are analysed for three hospital levels (local, county and university hospitals). The median age was 71 years (range 18-96 years). The median pretreatment delay was 113 days, and 46 per cent of patients had a performance status (Karnofsky index) of less than or equal to 80. The diagnosis was confirmed by pre-operative histology in 88 per cent of cases. In all, 88 per cent of patients underwent surgery, the resectability rate was 67 per cent and 50 per cent had a potential curative operation. Total gastrectomy was most commonly performed. Lymph node dissection was performed in 14 per cent of those undergoing a curative resection. The postoperative complication rate was 27 per cent but varied with the type of operation, being highest in proximal resection (55 per cent) and lowest after distal resection (19 per cent). A total of 7 per cent of the patients died postoperatively. Most patients had advanced disease at the time of treatment and only 6 per cent had stage I tumours. There were significant differences in patient and treatment characteristics between the three hospital levels. In conclusion, patient selection bias which will influence results does occur. A fairly aggressive attitude towards local disease was found, but the low proportion of patients undergoing lymph node dissection not only leads to questions regarding the efficacy of this treatment policy, but also casts doubt on the validity of staging of stomach cancer. Morbidity and mortality rates are still high. The consequences of the differences revealed between hospital groups are difficult to interpret. Proponents of both regionalization of treatment and small hospital care may find arguments for their case in the data.     

Microvascular decompression for hemifacial spasm: postoperative neurologic follow-up and evaluation of life quality

Microvascular decompression (MVD) is an effective and safe treatment in hemifacial spasm (HFS). Postoperative evaluations are usually made by neurosurgeons. Follow-up studies performed by neurologists and postoperative quality of life (QoL) investigations are lacking. All 25 HFS patients operated with MVD in our centre between 2000 and 2004 were evaluated with the recently validated HFS-7 scheme, extended with the item 'sleep disturbance due to HFS' (HFS-8). The patients underwent a careful neurological examination median 3 years after the operation. The evaluation focused on clinical aspects, changes in blood pressure and time until observable effect of MVD. The evaluation of HFS-7 questionnaire and the extended form (HFS-8) showed significant improvement in QoL after MVD. Neurological outcome was in almost all cases excellent or good. Eleven (44%) patients had no neurological deficits at all. Only one patient had serious complications with ipsilateral facial palsy, deafness, balance problems and vertigo. The other patients had minor neurological findings or symptoms. Eighteen (72%) patients experienced early effect within 3 months after MVD; seven (28%) patients had late effect between 6 and 14 months. Median age of the patients with late effect (62.6 years) was significantly higher than in those with early effect (52.7 years).     

Mechanisms by which the putative serotonin receptor antagonist metitepin alters nociception in mice

Summary The putative serotonin (5-HT) receptor antagonist metitepin (0.5 mg/ kg, intraperitoneally) produced hypoalgesia in the increasing temperature hot-plate test and hyperalgesia in the tail-flick test in mice. The effects of metitepin were not altered after depletion of 5-HT by the neurotoxin 5,7-dihydroxytryptamine (5, 7-DHT, 80 g free base, intracerebroventricularly) or the serotonin synthesis inhibitor p-chlorophenylalanine (PCPA, 400 mg/kg for 10 consecutive days). After chronic administration (2 or 5 mg/kg for 18 consecutive days) tolerance to the effect of metitepin (0.5 mg/kg) and cross-tolerance to the antinociceptive effect of the 5-HT agonist 5-methoxy-N,N-dimethyltryptamine (5-MeODMT, 3 mg/kg) was found in the hot-plate test but not in the tail-flick test. It is suggested that metitepin may block descending 5-HT transmission while more complex mechanisms of action are involved at supraspinal level. One possibility is that metitepin exhibits partial agonist properties or, alternatively, that the drug may block 5-HT subsystems which tonically enhance nociception.     

Interaction analysis of physician-patient communication: the influence of trait anxiety on communication and outcome

Little attention has been paid to how patients' personality traits interfere with the communication and the outcome of physician-patient interaction. We performed an experimental study with students with high and low trait anxiety as patients. One physician conducted a single consultation with 41 students applying two beforehand-specified consultation styles. Patients completed questionnaires concerning emotional state and satisfaction. The actual content of the consultations was analyzed by Roter interaction analysis system (RIAS). The physician gave more biomedical information to low-anxiety students than high-anxiety students. Students who provided a lot of biomedical information themselves were less tense after the consultation. However, students with high anxiety were more dependent on the physician actively asking biomedical questions for them to be able to deliver that same information. In contrast to low-anxiety students, those with high anxiety were less satisfied after consultations involving many psychosocial questions posed by the physician and a good deal of emotional talk on their own part. Compared to low-anxiety students, students with high anxiety were less satisfied and tenser after consultations with much positive emotional talk on the part of the physician. We conclude that physicians and educators should be aware that psychological and emotional communication may be experienced as intrusive and inappropriate by patients with high trait anxiety when they present minor somatic problems.     

Expression of VE-cadherin in zebrafish embryos: a new tool to evaluate vascular development.

We have identified the zebrafish homologue of VE-cadherin and documented its expression in the developing vascular system. The zebrafish VE-cadherin gene is specifically expressed in the vascular endothelial cell lineage beginning with the differentiation and migration of angioblasts and persists throughout vasculogenesis, angiogenesis, and endocardium development. Staining zebrafish embryos by whole-mount in situ hybridization with the VE-cadherin probe provides a method to screen embryos for vascular defects. To illustrate this utility, we used VE-cadherin expression to demonstrate a conservation of vascular endothelial growth factor-A (VEGF-A) function. The morpholino antisense oligonucleotide knockdown of VEGF-A function in zebrafish embryos results in a loss of angiogenic blood vessels, as indicated by the lack of VE-cadherin expression in the intersegmental vasculature. This loss can be restored in embryos supplemented with either zebrafish or human VEGF-A, the latter indicating that genes crucial to angiogenesis have highly conserved functional activities in vertebrates.     

Increased behavioural response to intrathecal serotonin after lesion of serotonergic pathways with 5,7-dihydroxytryptamine seems not to be due to depletion of serotonin

The behavioural response to intrathecal i.th. serotonin (5-HT) was examined in mice pretreated with the neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) or the 5-HT synthesis inhibitor p-chlorophenylalanine (PCPA) which produce similar extensive depletion of central 5-HT levels. Intrathecal 5-HT (0.4 micrograms) elicited a behavioural response consisting of reciprocal hindlimb scratching and biting or licking of the hindquarters indicative of nociceptive stimulation. The response to i.th. 5-HT was markedly increased 5 days after intracerebroventricular (i.c.v.) injection of 5,7-DHT (80 micrograms base per mouse). On the other hand, 24 h after the last pretreatment injection of PCPA (400 mg kg-1 for 6 consecutive days), the response to i.th. 5-HT was unaltered. These results indicate that i.c.v. 5,7-DHT produces supersensitivity to 5-HT. Since PCPA failed to alter the effect of 5-HT, the supersensitivity seems not to be due to depletion of 5-HT levels after the lesion.     

Haemodynamic and neurohumoral effects of cold pressor test in severe heart failure.

The effect of a cold pressor test (CPT) on haemodynamics in relation to general and regional sympathetic activity and arginin vasopressin (AVP), was studied in eleven patients with severe congestive heart failure (CHF). Compared to an age-matched control group (C), resting arterial plasma noradrenaline (NA) (419 +/- 77 vs. 182 +/- 15 pg ml-1), and adrenaline (A) (142 +/- 28 vs 54 +/- 10 pg ml-1) were higher (P less than 0.05) in CHF. AVP showed no significant difference (14 +/- 4 vs. 9 +/- 4 pg ml-1). During CPT systolic and diastolic blood pressure and systemic vascular resistance increased (P less than 0.01), as did NA (delta 114 +/- 39 pg ml-1, P less than 0.01), A (delta 33 +/- 10 pg ml-1, P less than 0.01) and heart rate (delta 10 beats min-1, P less than 0.01). The myocardial v-a difference of NA decreased (P less than 0.05), but was unchanged across the renal vascular bed during CPT. The a-v difference of NA in the hepatic vascular bed, and fractional extraction of A in the coronary sinus, renal and hepatic vascular beds remained unchanged during CPT. AVP did not change significantly and no change in cardiac index or left ventricular filling pressure was observed during CPT. These data suggest that despite an increased activation of the sympathetic nervous system at rest, a further increase in blood pressure and catecholamines took place during CPT. Thus, the effect of a CPT which activates the central sympathetic system seems not to be altered in patients with severe CHF.