Limitations of the keyhole technique for quantitative dynamic contrast-enhanced breast MRI

The effect of keyhole data acquisition on quantitative analysis of dynamic MRI was examined. Experiments were performed retrospectively on raw data obtained from clinical dynamic contrast-enhanced breast imaging procedures. The effects of keyhole phase-encoding acquisition and type of reconstruction algorithm on the accuracy of derived quantitative parameters was assessed. Results indicate that the minimum keyhole size used should be restricted by the approximate minimum size of the expected lesions. Furthermore, reconstruction algorithms that offer improved image resolution do not circumvent this restriction.     

Gastro-oesophageal reflux disease: Medical or surgical treatment? Report of an interactive workshop

Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper.     

Management and survival of meconium ileus. A 30-year review.

Cystic fibrosis patients born with meconium ileus (MI) have had an improved outcome over the last three decades. The authors reviewed the impact of surgical management and long-term nutritional care on the survival of patients with MI. Of the 59 cases of MI seen from 1959 to 1989, 48 cases were managed operatively using either the Bishop-Koop ileostomy (BK), the Mikulicz ileostomy, primary resection and anastomosis (RA), or ileostomy. Six-month survival of MI has improved from 37% to 100%. Nonoperative cases (n = 11) had 100% long-term survival. The RA survivors required less late operative intervention (20%) as compared with other surgical patients (81%). A comparison of serial growth percentiles of CF patients with MI with those of their non-MI CF peers showed similar long-term decreases. These data confirm: (1) There is an improved survival for MI independent of the surgical procedure; (2) The BK ileostomy is an effective and time-tested MI treatment; (3) Primary resection and anastomosis in selected cases may have a lower surgical morbidity rate; and (4) Meconium ileus does not adversely affect the long-term nutritional outcome of CF patients.     

Acute volaemic changes modify the gastroduodenal resistance to the flow of saline in anaesthetized dogs

The effect of acute and sequential volaemic changes on the gastroduodenal flow of saline was assessed in 23 anaesthetized dogs following two different experimental protocols. Hypervolaemia, by i. v. infusion of saline, induced a gradual decrease on gastroduodenal flow which amounted to 76% below control values (P < 0.001) when volaemic expansion attained 5% of body weight. This effect was volume dependent (17% increase on gastroduodenal flow per volume of infused saline equivalent to 0.5% of body weight, P < 0.001), lasted for at least 90 minutes after infusion was completed and was also obtained by expanding previously bled animals. Hypovolaemia due to bleeding was followed by an increase on gastroduodenal flow of about 88% above control values (P < 0.05) when haemorrhage was equal to 3% of body weight. This effect was also volume dependent (23 % increase on gastroduodenal flow per volume of blood shed equivalent to a 0.5% of body weight, P < 0.01) and was reversed after blood volume was restored. These modifications in the resistance of the gastroduodenal segment to the flow of liquid due to acute volaemic changes suggest that the extracellular fluid volume modulates the contractile activity of the gastroduodenal portion of the gut possibly to set a gastroduodenal handling of liquid adequate to cope with volaemic imbalances.     

Prospective trial of supranormal values as goals of resuscitation in severe trauma.

We prospectively tested the effect of the early postinjury attainment of supranormal values of cardiac index (> or = 4.52 L/min per square meter), oxygen delivery (> or = 670 mL/min per square meter), and oxygen consumption (> or = 166 mL/min per square meter) on outcome in traumatized patients with an estimated blood loss of 2000 mL or more. The goals in control patients were to attain normal values for all hemodynamic measurements. During the 6-month period, 33 protocol patients and 34 control patients with similar vital signs, estimated blood losses, and severity of injuries were enrolled in the study. Eight (24%) protocol patients died, while 15 (44%) control patients died. The protocol patients had fewer mean (+/- SEM) organ failures per patient (0.76 +/- 1.21 vs 1.59 +/- 1.60), shorter stays in the intensive care unit (5 +/- 3 vs 12 +/- 12), and fewer mean days requiring ventilation (4 +/- 3 vs 11 +/- 10) than did the control patients (P < .05 for each). We conclude that attaining supranormal circulatory values improves survival and decreases morbidity in the severely traumatized patient.     

Differential modulation of Purkinje cell activity by enkephalin and corticotropin releasing factor.

Several peptides have been localized within afferents to the opossum's cerebellum, including cholecystokinin (15), enkephalin (16, 17) and corticotropin releasing factor (7, 9). Each of these peptides has a heterogeneous laminar and lobular distribution. Two peptide, enkephalin (ENK) and corticotropin releasing factor (CRF) are present in specific populations of climbing fibers and mossy fibers, which have an overlapping distribution in several areas of the cerebellum, in particular the lateral aspect of vermal lobules VII and VIII. Within this location ENK and CRF are co-localized in individual climbing fibers and mossy fibers (7). In the present study, the physiological effects of these peptides on Purkinje cell activity were analyzed. The data indicate that ENK and CRF have opposite effects on Purkinje cell activity. ENK suppresses spontaneous activity as well as that induced by application of glutamate and aspartate, as described previously (5). In contrast, CRF enhances both spontaneous and amino acid-induced unit activity. Further, when applied simultaneously, CRF blocks the suppressive effect induced by ENK. Previous studies have shown that climbing fibers, as well as the mossy fiber-parallel fiber pathway, are excitatory to Purkinje cells (11). However, immunohistochemical data have shown that these afferents are heterogeneous with respect to their chemical content (7-9, 15-17, 25). As found in the current and previous studies (3, 5) peptides in climbing and mossy fibers modulate the responsiveness of Purkinje cells to primary excitatory neurotransmitters in selected areas of the cerebellar cortex. However, the firing rate of individual Purkinje cells is differentially altered depending on which neurochemical messenger(s) are released.(ABSTRACT TRUNCATED AT 250 WORDS)     

Neuropathological Effects of Triphenyl Phosphite on the Central Nervous System of the Hen (Gallus domesticus)

The neurotoxic effects of single subcutaneous injections of1000 mg triphenyl phosphite (TPP)/kg body weight were investigatedin White Leghorn hens. At 7 days postexposure, birds began toshow signs of mild to moderate ataxia that progressed to severeataxia and paralysis at 21 days. Inhibition of whole brain neuropathytarget esterase was 85% at 48 hr and 73% by 21 days postexposure.After postexposure periods of 7, 14, and 21 days, hens werekilled and their brains and spinal cords were examined for degeneratingaxons and terminals using the Fink-Heimer silver impregnationmethod. A small amount of degeneration was noted at 7 days.By 21 days, dense degeneration was noted in the spinal graymatter and funiculi. Degeneration was also present in the granularcell layer of cerebellar folia I-VI and in nuclei and fibertracts of the medulla. Moderate to dense degeneration was alsoseen in several forebrain and midbrain areas including the paleostriatum,ansa lenticularis, the dorsointermediate thalamic nucleus, lateralspiriform, pedunculopontine tegmental, and lateral mesencephalicnuclei and in the deeper layers of the optic tectum. These resultsindicate that, in addition to affecting the spinal cord andbrainstem, exposure to TPP also damages higher order centersresponsible for processing and integrating sensorimotor, visual,and auditory information.