Abnormalities of the neonatal brain: MR imaging. Part II. Hypoxic- ischemic brain injury

Eighty-five infants, 82 of whom were 29-44 weeks postconceptional age, were imaged with a 0.6-T magnet. Eight infants had cerebral infarction. In premature neonates with very water, low-intensity white matter on T1-weighted images, ultrasound was better than both computed tomography and magnetic resonance (MR) imaging in depicting parenchymal changes of infarction or edema. However, after 37 weeks gestation, MR imaging was superior. Cerebral atrophy, present in seven infants, was consistent with subarachnoid space widths of 7 mm or more, or subarachnoid space widths of 5-6 mm with ventricular/brain ratios of 0.36 or greater. Delayed myelination was seen in a total of 18 infants with histories of hypoxic-ischemic insult. MR imaging shows promise in the neonatal period. It facilitates recognition of infarcts in full-term infants and may be used to predict abnormal neurologic outcome in infants who have initial delayed myelination.     

Identifying relevant diagnostic studies in MEDLINE. The diagnostic value of the erythrocyte sedimentation rate (ESR) and dipstick as an example

OBJECTIVE: We aimed to examine sensitivity and positive predictive value of MEDLINE searching for diagnostic studies, relevant for the primary health care setting. METHOD: Results of MEDLINE searches were compared with a reference standard collection of studies on two subjects, the diagnostic value of ESR in discriminating between 'pathology' and 'no pathology', and the dipstick method in diagnosing urinary tract infections. The main outcome measures were sensitivity (proportion of the total number of reference standard diagnostic studies that could be identified by the search) and positive predictive value (proportion of the total number of publications retrieved by MEDLINE that were incorporated in the reference standard). RESULTS: The combined MeSH and freetext search was more sensitive than MeSH term searching only, for both the ESR and the dipstick search. With this combined search sensitivities of 0.91 and 0.98 and predictive values of 0.10 and 0.68 were found for ESR and dipstick respectively. By restricting the search with keywords describing the primary health care setting the predictive values increased to 0.72 and 1.00 but sensitivity dropped to 0.10 and 0.07 (ESR and dipstick respectively). CONCLUSION: Combining freetext and MeSH term searching, without restriction to the primary health care setting, is a valuable strategy in systematically searching for available evidence on the value of a diagnostic test in the scope of a specific disease. The predictive value seems to depend on the breadth of the disease area. MEDLINE should provide a term such as 'diagnostic evaluation study' to be used in the limit field Publication Type to specify diagnostic studies.      

HORNER'S SYNDROME: AN UNUSUAL IATROGENIC COMPLICATION OF PNEUMOTHORAX

SUMMARY A patient is reported with spontaneous pneumothorax in whom a Horner's syndrome occurred as a complication of drainage tube thoracostomy. Ascending sympathetic fibres lie in close contact with the parietal pleura at the apex of the hemithorax and may be damaged by an inappropriately positioned thoracostomy tube. It is suggested that drainage tubes found to be sited medially at the apex of the hemithorax should be immediately repositioned to avoid this complication.     

Bench-to-bedside review: Paediatric viral lower respiratory tract disease necessitating mechanical ventilation – should we use exogenous surfactant?

Treatment of infants with viral lower respiratory tract disease (LRTD) necessitating mechanical ventilation is mainly symptomatic. The therapeutic use of surfactant seems rational because significantly lower levels of surfactant phospholipids and proteins, and impaired capacity to reduce surface tension were observed among infants and young children with viral LRTD. This article reviews the role of pulmonary surfactant in the pathogenesis of paediatric viral LRTD. Three randomized trials demonstrated improved oxygenation and reduced duration of mechanical ventilation and paediatric intensive care unit stay in young children with viral LRTD after administration of exogenous surfactant. This suggest that exogenous surfactant is the first beneficial treatment for ventilated infants with viral LRTD. Additionally, in vitro and animal studies demonstrated that surfactant associated proteins SP-A and SP-D bind to respiratory viruses, play a role in eliminating these viruses and induce an inflammatory response. Although these immunomodulating effects are promising, the available data are inconclusive and the findings are unconfirmed in humans. In summary, exogenous surfactant in ventilated infants with viral LRTD could be a useful therapeutic approach. Its beneficial role in improving oxygenation has already been established in clinical trials, whereas the immunomodulating effects are promising but remain to be elucidated.     

Chest injury in children with blunt abdominal trauma: evaluation with CT

One or more significant chest injuries were identified in 62 of 512 children (12%) examined with computed tomography (CT) after blunt abdominal trauma. Thirty-eight percent of all abnormalities identified on CT scans were underestimated or missed on the initial chest radiograph. Pleural and parenchymal abnormalities were missed in 50% and 34% of initial chest radiographs, respectively. Chest injuries occurred more frequently in children less than 7 years of age than in older children (62% vs 38%, P less than .02). Children with chest injuries tended to be more physiologically unstable than children without, as determined with lower (worse) mean trauma scores (P less than .001). Both the presence and severity of chest injuries strongly affected outcome. Mortality was 1.3% in children with no chest injury, 10.8% in children with significant unilateral chest injury, and 40% in children with significant bilateral or mediastinal chest injury (P less than .0001). Significant unsuspected or underestimated thoracic injuries are relatively common in children, and CT scans of the chest obtained while examinations of the upper abdomen are being performed can be helpful in the early recognition of such injuries.     

Morphology of the ovary of Caiman crocodilus (Crocodylia: Alligatoridae).

We describe the ovarian histology and characterize the folliculogenesis of adult females of Caiman crocodilus in order to compare them with other species of Reptilia. The gonad has a thin irregular cortex and a well-developed reticular stroma, composed of vascularized chordae, drained by large lymphatic vessels and separated by extensive lacunae. Simple cuboidal to squamous epithelium, dense connective tissue with numerous elastin fibers, and smooth muscle constitute the ovarian wall. This morphology is similar to that of other Crocodylia, Aves and Testudines. Germinal nests are distributed in the ovarian cortex, some of them with oogonia. Oocytes leave the germinal nests with a single layered cuboidal granulosa, remaining simple during vitellogenesis, as in other Archosauria and Testudines and different from Squamata. As the oocyte grows, the theca is formed by numerous fibroblasts, collagen fibers, and smooth muscle fibers, becoming very thick, highly vascularized and developing muscle bands at advanced vitellogenesis. Folliculogenesis shares morphological features with other species of Reptilia. The corpus luteum is similar to that described for Archosauria; during luteolysis, the theca shrinks and the amount of luteinic cells decreases. The relationship of the corpus luteum to vitellogenesis and egg maintenance is unclear in Crocodylia. Follicular regression in Caiman crocodilus corresponds to an invasive atresia type. Histological features seen in the ovary of Caiman crocodilus are similar to those described in Alligator mississippiensis indicating that these features could be shared among Crocodylia. Also several of these morphological characteristics are observed in Aves suggesting a similar reproductive functional morphology in Archosauria.