Small-dose nitric oxide improves oxygenation during one-lung ventilation: an experimental study

Inhaled nitric oxide (NO) at 20 or 40 ppm does not improve arterial oxygenation during one-lung ventilation (OLV). The authors hypothesized that NO at smaller concentrations might improve oxygenation. Twelve piglets weighing 26 to 32 kg were studied. When PaO(2) had reached a plateau during OLV, NO at doses of 4, 8, 16, and 32 ppm were randomly administered for 30 min. Hemodynamic data were determined by invasive monitoring. Blood gas analysis and, in six animals, ventilation-perfusion analysis by the multiple inert gas elimination technique were used to characterize pulmonary gas exchange. NO at 4, 8, 16, and 32 ppm improved PaO(2) during OLV. NO at 4 ppm had a more intense effect on arterial oxygenation than doses of 8, 16, and 32 ppm (DeltaPaO(2), 42 +/- 35 mm Hg versus 22 +/- 20 mm Hg, 13 +/- 18 mm Hg, and 15 +/- 16 mm Hg; P < 0.05). NO at 4 ppm reduced intrapulmonary shunt flow, whereas a larger concentration exhibited no statistically significant effect. The authors conclude that NO improves arterial oxygenation more effectively at smaller doses than at larger doses. This dose-dependent effect remains to be confirmed in acute hypoxemia during OLV. IMPLICATIONS: Inhaled nitric oxide at 4 ppm improves arterial oxygenation during one-lung ventilation to a greater extent than larger doses, and this effect is caused by a reduction in intrapulmonary shunt.     

Norwegian oncologists' expectations of intensity-modulated radiotherapy

Although intensity-modulated radiotherapy (IMRT) may increase the therapeutic ratio of radiotherapy for a range of malignancies, only a few IMRT treatments have yet been performed in the Nordic countries. The scores derived from a national survey to assess Norwegian oncologists' expectations of IMRT are presented. A questionnaire was distributed to all consultants in oncology at Norwegian radiotherapy clinics. Summary scores of daily general radiotherapy workload (DGRTW), acquaintance with IMRT (AI) and expectations of IMRT (EI) were derived. Thirty-nine questionnaires (67%) were returned from a total of 58 oncologists. The oncologists' scores on the AI scale (mean score: 7.5 out of 21) were rather low. Their AI scores were found to be positively correlated with their DGRTW. Higher scores on the EI scale were documented (mean score: 6.2 out of 14): 15 oncologists (39%) rated IMRT as one of the three major contributors to potentially increased cancer survival. Oncologists treating patients with prostate, head and neck, gastrointestinal and CNS tumours had higher EI scores than the other oncologists (7.7 vs. 5.1; p=0.01). The Norwegian radiation oncologists' expectations of IMRT are high in terms of both the potential clinical benefit and the rate of implementation. This should encourage the radiotherapy communities to continue (or rapidly initiate) their efforts in providing the routines required for safe implementation of IMRT.     

The origin of lactation as a water source for parchment-shelled eggs

Available evidence indicates that mammary gland secretions first evolved in synapsids that laid parchment-shelled eggs. Unlike the rigid-shelled eggs of birds and some other sauropsids, parchment-shelled eggs lose water very rapidly when exposed to ambient air of lower vapor pressure, whether due to differences in relative humidity or to differences in temperature. This precludes endothermic incubation of parchment-shelled eggs in an open nest. Synapsids may have avoided egg desiccation by incubating eggs in a pouch, but this would limit maternal activity. Parchment-shelled eggs are able to take up liquid water across the eggshell. I propose that mammary secretion originally evolved as a means of supplying water to eggs, and as such was essential to the evolution of endothermy among the egg-laying cynodonts that were ancestral to mammals. It is possible that synapsid eggs, like parchment-shelled squamate eggs, were also capable of uptake of some nutrients, such as sodium and ionic calcium. Living monotremes still produce parchment-shelled eggs. The porous eggshell and bilaminar yolk sac membrane of these eggs permit substantial uptake of uterine secretions during the intrauterine period, and might also facilitate uptake of mammary secretions during egg incubation. In its simplest form, mammary secretion may be an ancient trait of egg-laying synapsids, having had an important role long before milk became obligatory for suckling young.     

A concomitant tumour boost in bladder irradiation: patient suitability and the potential of intensity-modulated radiotherapy.

BACKGROUND AND PURPOSE: In radiotherapy (RT) of bladder cancer, dose escalation without increased adverse effects could be achieved with a concomitant bladder tumour boost. In this study we quantified (1) the fraction of patients suitable for this approach, and (2) the potential of intensity-modulated RT (IMRT) to achieve this boost while also sparing normal tissues. MATERIALS AND METHODS: The fraction of patients suitable for this boost approach was quantified using both a series of 30 radical therapy candidates, and a series of 15 consecutive RT patients. IMRT plans with 3, 5, 7 and 9 equi-spaced beams were set up for the patients in the RT series found suitable for a boost. Two sets of targets were defined, with (i) wide and (ii) narrow margins around both the tumour (prescribed 120% dose) and the non-involved bladder (prescribed 100% dose). The inverse planning optimisation minimised the dose deviation across the targets whilst fulfilling dose-volume histogram (DVH) constraints--based on what could be achieved with conformal RT (CRT)--for both the normal tissues and the targets. RESULTS: Fourteen of the 30 radical therapy candidates (47%) and 10 of the 15 RT patients (67%) were suitable for a boost. The 20% boost could be obtained while maintaining target coverage with at least one IMRT plan in 9 of 10 cases with wide margins and for all 10 cases with narrow margins. Using wide margins, all 3-field plans were unacceptable, the 5-field plans were acceptable for 5 of 10, and the 7- and 9-field plans for 9 of the 10 patients. The normal tissue volumes receiving doses >100% were on average reduced by a factor of 3-4 compared with CRT. The normal tissue volumes receiving intermediate doses (73-88%) decreased slightly, whereas volumes receiving the lowest doses (30-48%) increased with the number of beams. The use of narrow margins resulted in markedly lower normal tissue irradiation. CONCLUSION: This study has shown bladder tumour boosting to be both clinically relevant and technically feasible using IMRT. This approach is ready for clinical implementation, although further improvement could be expected if integrated with target localisation techniques.     

Vaginoperitoneal fistula and fallopian tube prolapse after total laparoscopic hysterectomy

Vaginoperitoneal fistula and fallopian tube prolapse are uncommon after hysterectomy, whether vaginal or abdominal. The main symptoms are leukorrhea and discharge that mimic urinary incontinence. A case report with a complex history of endometriosis, several surgical procedures, and total laparoscopic hysterectomy (TLH) is presented, and the diagnostic procedures and laparoscopic repair are discussed.     

Circulatory responses in children with unexplained syncope evaluated by continuous non-invasive finger blood pressure monitoring

Cardiovascular responses on active standing in children with unexplained syncope were investigated with continuous non-invasive finger artery pressure monitoring (Finapres). We examined 34 symptomatic patients (13 boys and 21 girls), aged 8–16 years, and 24 age-matched controls. Finger blood pressure and heart rate were monitored continuously for 5 min in the supine position and for 10 min while standing. Ten of 34 patients developed fainting symptoms with hypotension during upright posture (fainters). In the initial standing phase (0–30 s), two prominent abnormal blood pressure responses were found in patients: a marked decrease 45 f 18/23 ± 8 mmHg and a prolonged recovery time (16.5 ± 2.9 versus 27.7 ± 13.6 s), which appeared to be based on impaired vasoconstriction. Either or both abnormalities were observed in 21 (62%) of the 34 patients and in 2 (8%) of the controls. In addition, fainters also had a more marked increase in heart rate during standing compared with non-fainters. Our findings suggested that more than half of children with syncope had abnormal cardiovascular reflexes in the initial phase which appeared to be associated with vasodepressor syncope. The active standing test with a continuous beat-to-beat blood pressure recording has a high sensitivity in detecting abnormalities of autonomic function in patients with unexplained syncope.     

The Effect of Breathing on the Cardiovascular Adjustments Induced by Face Immersion in Man

Andersen (1963) has reported that bilateral interruption of the trigeminal nerve abolishes submersion bradycardia typical of ducks. A slowing of the heart upon face immersion of man has later been reported by several authors. (Craig 1963, Elsner et al. 1963, Brick 1966, Paulev 1969 and Song et al. 1969). Arrest of breathing, how ever, is obviously a consequence of face immersion of normal subject?. It would therefore be of interest to repeat these experiments in a person, who has the ability to continue to breathe normally while his head is kept under water i.e. a tracheosto-mized man. Studies of the heart rate related to face immersion in this person may furnish valuable information concerning the afferent pathways involved in the establishment of the cardio-vascular adjustments to diving in man.     

Endovascular repair of abdominal aortic aneurysm in octogenarians: an analysis based on EUROSTAR data

PURPOSE: To investigate the early and late outcome after endovascular treatment of abdominal aortic aneurysm (EVAR) in octogenarians compared with patients aged < 80 years. METHODS: Patients treated for abdominal aortic aneurysm (AAA) with endovascular repair during the period 1996 to 2004 were collated in the EUROSTAR registry. This study group consisted of 697 patients aged > or = 80 years. Comparison was made with 4198 patients aged < 80 years with regard to the incidence of preoperative characteristics and outcomes of the procedure. RESULTS: The proportion of octogenarians treated by EVAR increased during the study period, from 11% in the first year to 18% in the last year. Octogenarians more frequently had cardiac disease, impaired renal function, and pulmonary disease (P = .03, P < .0001 and P = .0001). Thirty-two percent of the octogenarians were recorded unfit for open surgery as opposed to 22% in younger patients (P < .0001); they also had a larger aneurysm diameter (62 vs 58 mm, respectively; P < .0001). The 30-day and in-hospital mortality in octogenarians was 5% vs 2% in the younger group (P < .0001). More device-related complications and systemic complications, including cardiac disease, were noted in octogenarians (7% vs 5% and 19% vs 11%, P = .03 and P < .0001, respectively). This group of patients also had a higher incidence of postoperative hemorrhagic complications, including hematoma (7% vs 3%, P < .0001, respectively). No differences in conversion to open repair and post-EVAR rupture rate were observed. Aneurysm-related mortality and late all-cause mortality was 7% vs 3% and 10% vs 7%, both P < .0001. CONCLUSION: Our study supports that EVAR might be considered when treating elderly patients, provided their aneurysms are anatomically suited for the endovascular technique. The risk for late complications compared with open repair may be outweighed by a lower early mortality as well as a shorter time for physical recovery.     

Histopathological outcome in 167 patients operated on with radical retropubic prostatectomy

OBJECTIVE: To evaluate the histopathological outcome in patients with prostate cancer operated on with radical retropubic prostatectomy. MATERIAL AND METHODS: A total of 167 patients with clinically organ-localized prostate cancer treated with open radical retropubic prostatectomy between 1996 and 2001 were divided into three equally sized consecutive cohorts (cohorts I-III). The prostatectomy specimens were re-examined by two pathologists with respect to pathological tumour stage, tumour grade and surgical tumour margins. RESULTS: The mean preoperative prostate-specific antigen (PSA) value was statistically significantly higher in cohort I compared to cohorts II and III: 13.2, 9.0 and 8.5 ng/ml, respectively (p<0.05). The incidence of locally advanced (pT3a-3b) tumours was 44% in cohort I and 20% in both cohorts II and III (p<0.05). The incidence of positive tumour margins was 58% in cohort I, compared to 30% in cohort II and 13% in cohort III (p<0.05). The incidence of positive intracapsular tumour margins was 55% in cohort I, compared to 25% in cohort II and 8.9% in cohort III (p<0.05). The incidence of positive tumour margins in the pT2 tumours in cohorts I-III was 57%, 26% and 8.9%, respectively (p<0.05). Cohort III had significantly more low-grade tumours (Gleason score 4-6; 58.9%) compared to cohorts I (31.5%) and II (34%). There was a higher incidence of Gleason score >or=7 in the pT3 tumours compared to the pT2 tumours (80% vs 46%) and in margin-positive compared to -negative tumours (69.6% vs 48.6%) (p<0.05). CONCLUSIONS: The decline in pT3 tumours and positive tumour margins between cohorts I-III is probably due to a gradually more strict selection of patients for radical retropubic prostatectomy. The successive reduction in positive intracapsular tumour margins is most likely due to an improved surgical technique.     

Longitudinal studies on Listeria monocytogenes and other Listeria species in two salmon processing plants

Two plants processing salmon fillets and cold smoked salmon were investigated for occurrence of Listeria in products and the environment. Analyses were conducted for a period of 31 weeks. At plant A, 252 samples were examined of which 97 were from unprocessed fish and 155 from cold-smoked fish. At plant B, 189 samples of unprocessed fish were investigated. The first examination of unprocessed fish at plant A showed a presence of L. monocytogenes and L. spp. in 81% and 19% of the samples respectively. For cold-smoked fish the figures were 43% and 23%. At plant B, L. monocytogenes was isolated in 63% of the samples. During the test period, management at the processing plant initiated various hygiene precautions to improve the sanitary situation. The last batch of analyses of unprocessed fish at plant A showed a presence of L. monocytogenes and L. spp. in 42% and. 33% of the samples respectively. For cold-smoked fish, the figures were 6% and 11%. The isolation figures at plant B for L. monocytogenes and L. spp. were 50% and 17% respectively. The hygienic precautions did not have a significant effect on the presence of L. monocytogenes and L. spp. We suggest that Listeria bacteria are a part of the resident flora and are not eliminated by current cleaning and sanitation programmes. Cold-smoking, however, gave a significant reduction in the isolation of L. monocytogenes (P = 0.0082), while the isolation of L. spp. did not decrease after this process.