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There is considerable evidence to suggest that an FcR similar in structure to class I MHC Ags, neonatal Fc receptor (FcRn), transports IgG across the intestinal epithelium of suckling mice. However, this has not previously been shown definitively, nor has it been shown whether FcRn is the only, or even the major, IgG transporter in the neonatal mouse gut. We report here that neonatal mice homozygous for a targeted disruption of the beta 2microglobulin (beta 2m) gene, which encodes one subunit of FcRn, had reduced FcRn alpha-chain at the lumenal plasma membrane of intestinal cells. These mice had strikingly lower serum IgG levels during the first month after birth than littermates that possessed functional FcRn. Furthermore, we found by fostering mice on mothers with a different IgG allotype that all of the IgG in sera of beta 2m-/- mice was endogenous, and that none was obtained from milk. We conclude that FcRn is the only transporter of IgG from mother to young in the mouse. The onset of IgG synthesis in mice that received no milk IgG lagged behind that in siblings with normal IgG transport, suggesting that maternal IgG stimulates Ab production in the neonate. We noted no difference between the IgG concentrations in the milk of beta 2m-/- and beta 2m+/- mice, indicating that FcRn is not involved in the secretion of IgG into milk.

Mice transgenic for beta 2-microglobulin gene deletion (beta 2M-/-) can clear respiratory pathogens but at a slower rate than control mice. How these mice eliminate virus is not known, but the process is believed to involve CD4+ T cells. Recent studies from other laboratories have suggested a role for CD8+ cytotoxic T lymphocytes (CTLs) in both recognition of beta 2M deficient cells by allogeneic mice and rejection of MHC-incompatible tumor cells by beta 2M-/- mice. After influenza inoculation, we found no evidence for anti-influenza CD8 CTL activity from the lungs or spleens of beta 2M-/- mice. Anti-influenza CD4+, class-II restricted CTL activity was demonstrated from both the lungs and spleens. We next used mitogen-stimulated splenocytes from beta 2M-/- mice for targets in an in vitro CTL assay. This method for determining MHC class II CTL activity showed that the lungs and spleens of influenza-infected beta 2M-/- mice contained precursors to CD4+, but not CD8+, effector CTLs. The data indicate that CD8+ CTLs have no role in anti-viral activity in beta 2M-/- mice. Development of anti-tumor CTLs and anti-viral CTLs may arise via different mechanisms.

Previous work has suggested that human subjects engaged in tasks, like the Stroop task, that require response selection utilize the medial frontal cortex. We used positron emission tomography to measure blood flow changes in a stimulus-response compatibility task designed to maximize the demand on response selection processes. We report significant activation in the cingulate sulcus (Brodman's area 32) and a correlation of activity in this region with faster response time for an incongruent stimulus-response task.

A technique has been developed for automated detection of the intercommissural (AC-PC) line for positron emission tomography (PET). The AC-PC line is estimated from the location of four internal landmarks; the frontal and occipital poles, the inferior aspect of the anterior corpus callosum, and the subthalamic point. The landmarks are detected automatically in PET mid-sagittal slices by combining edge detection, interpolation and profile curve analysis techniques. The anatomical relationships between the true and estimated AC-PC lines from the landmarks was confirmed by analysis of magnetic resonance (MR) images. Accuracy of the automated estimation technique was assessed in co-registered PET and MR images, which showed minimal angular differences and displacements of the estimated from the true AC-PC lines. The automated detection of the AC-PC line in a PET study enables accurate stereotactic localization of functional signals without the need for additional anatomical imaging and provides a basis for objective and reproducible intersubject comparison.

We report in vitro and in vivo preclinical studies of a new cerebral blood flow tracer, [99mTc]N1-(2-mercapto-2-methyl-propyl)-N2-(2- propargylthio-2-methylpropyl)-1,2-benzenediamine (T691). The tracer demonstrates excellent in vitro chemical stability and accumulates regionally in the brain in a pattern consistent with that of cerebral blood flow. First-pass cerebral extraction determined with the use of the brain uptake index method in the rat was 0.76. Bolus intracarotid injection in monkeys indicated a cerebral extraction of 68% and prolonged retention of 67% of the initially extracted activity. Autoradiographic studies in rats revealed a pattern characteristic of cerebral blood flow at both 1 and 60 min after systemic injection. Dynamic tomographic imaging following systemic injection in the monkey revealed peak brain activity 1 to 2 min postinjection, without significant decline over 60 min. Chromatographic studies of brain as long as 60 min following systemic injection of [99mTc]T691 showed no evidence of tracer metabolism to account for its retention. Overall, [99mTc]T691 demonstrates promise as a potential new clinical tracer of cerebral perfusion.

To test the hypothesis that rapid eye movement (REM) sleep in schizophrenic patients is associated with cognitive function, we studied 18 schizophrenic inpatients by means of electroencephalograms taken during sleep in their own hospital beds after a minimum 2-wk medication withdrawal period. Patients underwent neuropsychological tests to measure memory function and other aspects of cognitive performance. REM sleep measures demonstrated positive and negative correlations with cognition and memory measures, depending on when REM occurred after sleep onset. Minutes of REM sleep and REM density in the first period correlated negatively with performance, while REM minutes occurring after the first REM period correlated positively with neuropsychological performance. Further work should test whether phasic REM sleep regulation at the beginning of the night plays a compensatory role for neuropsychological dysfunction in schizophrenics.

To study the effects of neuroleptic therapy on sleep EEG variables in schizophrenia, as well as the clinical correlates of these variables, we performed polysomnographic (PSG) studies on 14 schizophrenic inpatients before and during neuroleptic therapy. Sleep continuity measures improved after 3 weeks of neuroleptic therapy, showing decreased sleep latency and improved sleep efficiency. REM latency increased with treatment, although half the patients continued to exhibit REM latencies less than 60 min. Other sleep stages and measures of REM sleep (density, activity, number of periods) did not appear to change with neuroleptic treatment. At baseline, REM latency had strong negative correlations with BPRS and SANS scores, but with 3 weeks of such treatment, this association disappeared. Further work is needed to distinguish direct medication effects from the effects of the changing clinical state on PSG measures.

In an open-label prospective study the safety, efficacy, and patient tolerance of an enterally administered isotonic intestinal lavage solution containing polyethylene glycol-3350 was evaluated in 20 pediatric patients (ages 1 1/2 to 19 years) undergoing diagnostic colonoscopy. After an oral dose of metoclopramide, lavage solution was administered by mouth or nasogastric tube at a rate of 40 ml/kg per hour until stools were clear. Emesis occurred in 4 patients, nausea in 11, and abdominal distension in 5. Clear stools were produced in a mean (+/- SE) time of 2.6 +/- 0.3 hours. The volume of lavage solution delivered, which ranged from 15.6 to 183.3 ml/kg, varied inversely with the weight (and age) of the patient. Preparation of the colon was considered optimal in 11 patients, satisfactory in 7, and suboptimal in 2. Small but significant decreases in urine osmolality, blood urea nitrogen, serum glucose, and potassium values were noted at the termination of perfusion. Postperfusion serum glucose concentration in the smallest patient (11.4 kg) was 61 mg/dL (3.4 mmol/L). Mean (+/- SEM) change in weight after perfusion was 0.14 +/- 0.05 kg (range -0.2 to +0.6 kg). Of 20 patients, 11 required or requested nasogastric administration of the lavage solution because of its unpleasant taste. We conclude that whole intestinal perfusion with a balanced electrolyte solution containing polyethylene glycol is safe, acceptable, and efficacious in children.

We describe noninfectious bloody diarrhea in 13 of 16 infants referred for management of short bowel syndrome and parenteral nutrition during a 33-month period. The condition was characterized by bloody, watery stools associated with carbohydrate malabsorption. Colitis occurred at a mean age of 4.2 months during periods of advancing enteral feedings of a hydrolyzed protein- or amino acid-containing formula. Sigmoidoscopy performed in nine patients revealed edema, patchy erythema, loss of normal vascular pattern, and mucosal friability without ulcerations or pseudomembranes. Colonic biopsy specimens demonstrated edema and mixed hypercellularity of the lamina propria, with prominent eosinophilia. Rectal bleeding ceased if formula feedings were decreased or withheld. Of multiple medications administered, sulfasalazine seemed to improve rectal bleeding most effectively in our patients and allowed for more rapid reintroduction of enteral feedings.

Lymphangiomas result from abnormal development of the lymphatic system, with obstruction to lymph drainage from the affected area. The neck is the most common site (25%). In this study, we review the literature of lymphangioma in the neck and thorax and have undertaken detailed analysis of 52 children with cervical lymphangioma treated during the 20 years 1969-1988. Cervicomediastinal lymphangioma is uncommon (4%) and lesions confined to the thorax are rare, with none in our series. Neck lymphangiomas occur in early childhood with half being diagnosed at birth and almost 90% before school age. All have a mass. Two-thirds are asymptomatic; sudden enlargement, inflammation, infection, feeding difficulties and respiratory symptoms occur in the remainder. Pharyngeal and laryngeal involvement, usually associated with large infiltrating lesions, results in acute airways obstruction. The respiratory symptoms caused by mediastinal extensions are usually less dramatic. Lymphangiomas have a characteristic appearance on ultrasound examination and CT scan. These investigations are mandatory for an undiagnosed intrathoracic mass and when there is clinical suspicion of mediastinal extension of cervical lymphangioma but should be obtained for neck swellings only when the clinical diagnosis is in doubt. The recommended treatment is surgical excision which can be achieved with no mortality and little morbidity. An initial period of observation is justified for asymptomatic cervical lesions because there is a small incidence (6%) of spontaneous regression. Cervicomediastinal lymphangiomas can be removed at one operation using a neck incision combined with median sternotomy. The surgeon must preserve vital structures (especially vagus, recurrent laryngeal and phrenic nerves) and should not necessarily attempt total removal of all lymphangiomatous tissue. Massive infiltrating cervical lesions pose a particular challenge and may require multiple operations over many years before a satisfactory result with good-quality survival is attained.

Is the job of medical record department director substantially the same in any acute care hospital? If not, what are some of the differences in roles and responsibilities? This study addresses that question as it relates to medical record department directors in South Carolina acute care general hospitals.