Cloning and characterization of BS-cadherin, a novel cadherin from the colonial urochordate Botryllus schlosseri

The genomic DNA for a novel member of the cadherin family (BS-cadherin) was cloned and characterized from the colonial marine invertebrate, Botryllus schlosseri. Using a differential display of mRNA by means of PCR, a small cDNA fragment of 380 nucleotides was found to be specifically expressed in a colony undergoing allogeneic rejection processes, as compared with naive parts of the same genotype. This cDNA fragment was used as a probe to screen a genomic library of Botryllus schlosseri. A genomic fragment containing an ORF of 2718 nucleotides, with no introns, was isolated. The encoded protein exhibits a typical structure of cadherins; an extracellular domain with conserved repeated sequences (cadherin signatures), a single transmembrane domain and a conserved cytoplasmic tail region. The BS-cadherin amino-acid sequence shows 32-35% identity to mature classical cadherins type I, e.g., N-, P- and E-cadherin as well as mature classical cadherins type II, e.g., human cadherin-6, -8 and OB-cadherin. This cadherin represents a new cadherin gene family, evolutionarily distant to all other known classical cadherins.

Does number of beds reflect the surgical capability of hospitals in wartime and disaster? The use of a simulation technique at a national level

INTRODUCTION

The raw number of hospital trauma beds and occupancy has been used to assess the surgical capability of hospitals in wartime and disaster situations. The goal of this study was to examine and offer a better tool to determine the load of casualties that a hospital would be able to absorb and treat effectively during these situations.

METHODS

Simulation software was applied to various wartime scenarios. It assessed the usefulness of a computerized simulation of operating room (OR) function under loading of "standard wartime casualties." Comparison of the functioning of similar hospitals was undertaken in order to identify possible methods to optimize the care delivered. A "what-if" module was used to define the optimal way to absorb mass casualties within the known resources of a given healthcare system. Each hospital was tested under different loading of "standard casualties." Average waiting time for surgery was used as a marker of the constant decay in the standards of care with the increasing patient load.

RESULTS

Different, unique patterns of strategies for optimizing waiting periods were identified. Not all trauma centers responded by shortening waiting time by diverting the lightly injured patients from them either before or after triage. The reaction to alternate days' shift was unexpected. The temporal course of matching a patient with a functional operating room was more indicative of a hospital's capability to absorb casualties requiring surgery than was the pre-set number of beds available in the hospital.

RECOMMENDATIONS

The use of simulation techniques might be useful method to assess the nationwide surgical capability. This is a complex dilemma that cannot be predicted with trivial guessing, even when combined with previous experience of triaging. Analyzing the weak points and bottlenecks at a national level might help in creating preparedness protocols.

Videotaping in the admitting area: a most useful tool for quality improvement of the trauma care

The treatment of trauma patients in the admitting area is performed under stress and requires team work. The goals of this research were to develop and analyse the implementation process of videotaping trauma care. The Rambam Medical Center is a 900-bed referral teaching hospital. It serves a population of more than 1.5 million in northern Israel. The trauma unit has focused on various activities to increase the quality of trauma care over the past few years. We installed a video camera and taped the treatment as part of a programme for the quality improvement of trauma care. Reviewing the tapes was carried out by the trauma team under guidance in order to identify deviation from treatment protocols, errors in techniques, improper usage of time, equipment failure and problems in team work. After 3 years' experience, we found that videotaping is an accurate and inexpensive way of achieving quality control in the admitting area. It now serves as a regular method in Israeli trauma centres and we encourage others to try this method.

Optic neuropathy preceding acute retinal necrosis in acquired immunodeficiency syndrome

OBJECTIVE

To describe the clinical course of varicella-zoster optic neuropathy preceding acute retinal necrosis in patients with acquired immunodeficiency syndrome.

DESIGN

Case series.

SETTING

Two tertiary care centers in San Diego, Calif, and London, England.

PATIENTS

Three human immunodeficiency virus-positive men with previous cutaneous zoster infection, optic neuropathy, and necrotizing retinitis.

RESULTS

All patients had an episode of zoster dermatitis treated with acyclovir. Visual loss consistent with an optic neuropathy ensued, followed by typical herpetic retinitis. The cause of visual loss was not suspected to be varicella-zoster until after the retinitis occurred. Despite aggressive medical treatment, 4 of 6 eyes progressed to retinal detachment.

CONCLUSIONS

Varicella-zoster may cause an optic neuropathy in patients with acquired immunodeficiency syndrome, especially in those with previous shingles. A high index of suspicion is necessary to establish the diagnosis and begin early antizoster treatment.

Health and unemployment

This paper reviews the relationship between health and inadequate employment, especially unemployment. Poor physical or mental health can lead, via poor work performance, to job loss; however, studies that control for such selection effects are still scarce except for a few health outcomes. For example, aggregate-level studies typically find a positive association between unemployment and suicide rates over time. At the individual level of analysis, panel surveys of laid-off workers tend to find increased psychiatric problems such as depression and substance abuse. Few studies have evaluated interventions to prevent or reduce the adverse health effects of job loss. There have been even fewer studies of the health effects of other types of inadequate employment such as the increasingly prevalent forms of underemployment.

The significance of dorsal migration of the cord after extensive cervical laminectomy for patients with traumatic central cord syndrome

Central cord syndrome (CCS) resulting from traumatic cervical injury is often associated with cervical stenosis and/or spondylosis. The efficacy of multilevel laminectomy in the treatment of this condition has been controversial. The objective of this study was to validate by magnetic resonance (MR) imaging the occurrence of dorsal cord migration after extensive laminectomy for patients with the clinical syndrome of central cord damage and its relationship to the short-term outcome. During a 28-month period, the authors evaluated 20 patients (mean age 54 years) who sustained CCS after cervical spine trauma. Pre- and postoperative MR imaging assessed the adequacy of cervical cord decompression by multilevel laminectomy. All patients had cervical canal stenosis with complete obliteration of the anterior subarachnoid space over multiple levels. Seventeen patients initially had CCS of different degrees of severity. One had no motor deficit and two had motor complete with sensory deficits greater in their arms. Laminectomy, generally from C2 to C7 without facetectomy, was performed after plateau of neurological recovery (mean 17 days postinjury). Neurological assessment 3 months after operation revealed improvement in 12, stable function in 7, and progression of deficit in one with no mortality. The postoperative midsagittal MR images demonstrated adequate decompression with restoration of anterior cerebrospinal fluid space and posterior cord migration in 12 patients (60% of the 20), but only 8 of them also had improved function. MR imaging demonstrated that, in the presence of multilevel spondylosis/stenosis, laminectomy may provide adequate spinal cord decompression in patients with traumatic CCS.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of stimulus velocity and acceleration on smooth pursuit in motor neuron disease

Sinusoidal smooth pursuit eye movements were evaluated in 11 normals, five moderately and four severely affected motor neuron disease (MND) patients, using two target amplitudes and a range of frequencies. This enabled us to examine separately the effects of peak target velocity and acceleration on pursuit gain. Moderately affected patients showed an acceleration, but not a velocity saturation; severely impaired patients' performance declined with increased velocity. Smooth pursuit eye movements are thus impaired in MND, but the nature of this pursuit deficit is complex and changes with the progression of the disease.

[Head injuries from falls in children of 2 ethnic groups]

The highly prevalent problem of falls, the main cause of head injury in children, responds to preventive intervention. To aid in designing fall-prevention programs, we defined the pre- and post-hospitalization characteristics of children of 2 predominant Israeli ethnic groups: Jews (Group A) and non-Jews (Group B). In a prospective study conducted over a 10-month period in our emergency room during the morning shift, data from 274 patients aged 0-14 who presented with head injury due to a fall were collected. In Group B falls and damage were significantly more severe. Based on these differences in injury and in referral patterns between the 2 groups, a high-risk profile for head injury from falls in children was compiled to aid in designing an effective prevention program.

Single-view screening mammography: psychological, endocrine and immunological effects of recalling for a complete three-view examination

To investigate influences of a recall due to inconclusive findings on screening mammography, 45 women were examined with psychological ('mood' and 'coping'), endocrine and immunological tests immediately after complete mammography (first interview), 2-3 days after the initial screening mammography, and 3 weeks after the women had been informed of normal findings (second interview). The mood score in the first interview was significantly lower than in the second. No differences were found in the endocrine and immunological tests. The recall for complete mammography provoked a significant short-term emotional reaction not reflected in changes in the endocrine and immune functions.

The neural locus of binocular rivalry and monocular diplopia in intermittent exotropes

Patients with intermittent exotropia (strabismus) can either fixate normally or allow one eye to deviate outward by as much as 60 degrees. Two such patients (D.N. and K.C.) were studied and it was found that during eye deviation, binocular correspondence is maintained by completely 'remapping' egocentric space for the deviating eye alone using extraretinal signals from that eye. Also, by using foveal afterimages we showed that binocular rivalry occurs at a site earlier than this egocentric remapping, probably in area 17 itself. And finally, consistent with the neural remapping hypothesis, patient K.C. also experienced monocular diplopia; objects appeared double when viewed with the deviating eye.

A masked prospective evaluation of outcome parameters for cytomegalovirus-related retinal detachment surgery in patients with acquired immune deficiency syndrome

PURPOSE

The management of cytomegalovirus (CMV)-related rhegmatogenous retinal detachments in patients with acquired immune deficiency syndrome (AIDS) has been the subject of recent attention and controversy because of the high degree of variability in visual outcome, as well as significant differences in the reported incidence of profound postoperative optic atrophy. This study was designed to evaluate the various parameters affecting postoperative visual outcome, and to quantitate the degree of postoperative optic disc pallor.

METHODS

The results of 65 consecutive surgeries for CMV-related retinal detachments in 51 patients with AIDS were prospectively studied. Postoperative vision, survival, optic disc pallor, and retinitis extent were analyzed. Serial photographs of optic discs underwent masked evaluation.

RESULTS

Mean postoperative survival was 30 weeks (range, 2-146 weeks). Mean best postoperative visual acuity was 20/66 (range, 20/20-2/200) and mean final postoperative visual acuity was 20/100 (range, 20/25-no light perception). Analysis of visual outcome for eyes with no macular or papillo-macular retinitis showed a best postoperative visual acuity of 20/60 (range, 20/25-2/200) and mean final postoperative visual acuity of 20/80 (range, 20/25-no light perception). Postoperative vision was not affected by the presence of a preoperative macular detachment, with both groups (macula on or off detachments), achieving a best postoperative visual acuity of 20/60 in the absence of macular retinitis. Mild postoperative optic disc pallor was observed in 30% of surgical eyes at the final postoperative visit, and moderate pallor was noted in 13%. The mean degree of optic disc pallor was not different from the degree of optic disc pallor seen in fellow, nonsurgical eyes with CMV retinitis (surgical versus fellow nonsurgical eyes, 29% +/- 23% versus 26% +/- 30%; P = 0.64).

CONCLUSION

In this largest reported series of reattachment surgery for CMV-related retinal detachments, patients are experiencing increased postoperative survival, good vision, and relative optic nerve health.

Hemodynamic parameters in patients with acute cervical cord trauma: description, intervention, and prediction of outcome

The cardiovascular response of the patient with acute spinal cord injury (SCI) is known to be altered secondary to the cord injury. Our current protocol of managing the acute phase of patients with SCI includes invasive hemodynamic monitoring (with arterial line and Swan-Ganz catheter) and support with fluids and dopamine and/or dobutamine, titrated to maintain a hemodynamic profile with adequate cardiac output (to be determined by oxygen consumption and delivery) and a mean blood pressure of > 90 mm Hg. We feel that this protocol provides two benefits: 1) maintaining the mean blood pressure improves the morbidity of these patients by deterring ischemia and accompanying secondary insults; 2) aggressive monitoring and hemodynamic intervention help stabilize the hemodynamic status of these patients and make it possible to consider early surgery in selected cases. Our hypothesis is that the pulmonary vascular bed is more sensitive to the sympathectomized effect of acute complete cervical SCI. We analyzed the demographic, neurologic, and hemodynamic data of 50 consecutive patients during their first week postinjury. All had signs of myelopathy; 31 (62%) were considered clinically complete. Of the 50 patients, 9 (18%) died, 20 did not improve functionally, and 21 improved. The mean heart rate (82.1 +/- 13.3), blood pressure (94.4 +/- 9.4), pulmonary artery pressure (22 +/- 5) and wedge (12.7 +/- 3.4), cardiac index (4.5 +/- 0.9), systemic vascular resistance index (SVRI) (1637 +/- 399), pulmonary vascular resistance index (PVRI) (181 +/- 80), and oxygen transport (694 +/- 156) showed good response to the treatment. Because the measurements were obtained during treatment, they differ from the expected "classic sympathectomized" response, but they provide a database for further analysis of hemodynamic manipulation in SCI. An analysis of the hemodynamic parameters did not differentiate between complete and incomplete lesions or between patients with functional improvement. We determined, on the basis of the initial hemodynamic measurements, that no patient with a clinically complete motor deficit (Frankel Grade A+B) improved of the 10 who had measurements compatible with either: 1) PVRI < 100 with SVRI < 1200; or 2) PVRI < 115 with SVRI < 1300 or PVR/SVR ratio of < 0.08 when SVRI was < 1600. These patients could not have other measurements that showed low SVRI < 1350 with PVRI > 139. At odds with this unique group, 13 of 29 patients with the same clinical picture and without the above physiological criteria of severe hemodynamic deficit eventually improved (P < 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)

Cloning of LL5, a novel protein encoding cDNA from a rat pituitary library

While screening a rat pituitary cDNA library for a peptide hormone receptor, we identified a cDNA that represents a novel gene. The 3.8 kb cDNA has an open reading frame of 2.3 kb encoding a protein of 781 amino acids (M(r) = 87,507). Southern blot analysis of rat, mouse, bovine and human genomic DNAs revealed that a homologous gene is present in these species probably in a single copy. Northern blot analysis showed that in addition to the pituitary gland, the gene is also expressed in other rat tissues. Scanning of DNA and protein databanks revealed no significant homology to any other sequence. Thus, this gene encodes a heretofore unidentified protein.

A physiological coma scale: grading of coma by combined use of brain-stem trigeminal and auditory evoked potentials and the Glasgow Coma Scale

Forty-five comatose patients were prospectively studied by means of clinical examination and evoked potentials. In each patient, clinical data included Glasgow Coma Scale (GCS) score, age, pupillary response to light, corneal reflex, and eye movements. Neurophysiological evaluation was based on brain-stem trigeminal evoked potentials (BTEPs) and brain-stem auditory evoked potentials (BAEPs). For each physiological test, a progressive grading system was designed. This system was based on the evaluation of central conduction times along the trigeminal and the auditory pathways within the brain-stem. The accuracy of the clinical and the neurophysiological indicants in predicting "favorable" or "unfavorable" outcome was assessed singly and in combination. Of the clinical indicants, the GCS provided the most accurate prognosis (80%). Similar results were provided by the BAEP and the BTEP, with significant improvement in the confidence of outcome prediction. No significant difference in the accuracy of outcome predictions could be found between combined clinical data and neurophysiological data. However, the combination of clinical and neurophysiological data markedly increased both the accuracy and the confidence of outcome prediction, reaching 86% correct predictions at the over 90% confidence level with only 2% false pessimistic errors. According to these findings, a clinical-physiological coma scale, the trigeminal-auditory Glasgow (Coma Scale) score (TAG score) was designed. The TAG score demonstrated the highest accuracy at each confidence level as compared to other single indicants. We concluded that the TAG score may improve the evaluation of deep comatose patients and assist the physician in the management of such patients.

Effect of THAM upon outcome in severe head injury: a randomized prospective clinical trial

Although mortality and morbidity rates from head injury have been reduced substantially by improved prehospital interventions, intensive care, and aggressive management of intracranial pressure (ICP), successful treatment of the primary brain injury has been elusive. In experimental models, tromethamine (THAM) has been effective in treating head injury; this drug acts by entering the cerebrospinal fluid compartment, reducing cerebral acidosis and ICP, and reversing the adverse effects of prophylactic hyperventilation on early recovery. In this randomized prospective clinical trial, THAM was studied to determine if it had beneficial effects in the early management of severe head injuries and if the adverse effects of hyperventilation could be prevented. A total of 149 patients with severe head injury (Glasgow Coma Scale scores of < or = 8) were randomly assigned to either a control or a THAM group. Both groups of patients matched in terms of clinical parameters, including age, sex, number of surgical mass lesions, number in each Glasgow Coma Scale stratum, and first ICP measurement. All patients were treated by a standard management protocol, intubated, mechanically ventilated, and maintained in the pCO2 range of 32 to 35 mm Hg for 5 days. Tromethamine was administered as a 0.3-M solution in an initial loading dose (body weight x blood acidity deficit, average 4.27 cc/kg/hr) given over 2 hours, followed by a constant infusion of 1 ml/kg/hr for 5 days. Outcome was measured at 3, 6, and 12 months postinjury. Although analysis indicated no significant difference in outcome between these two groups at 3 months, 6 months, and 1 year, there was a difference regarding ICP. The time that ICP was above 20 mm Hg in the first 48 hours postinjury was less in patients treated with THAM (p < 0.05). Also, the number of patients requiring barbiturate coma was significantly less in the THAM group (5.48% vs. 18.4%, p < 0.05). The authors conclude that THAM ameliorates the deleterious effect of prolonged hyperventilation, may be beneficial in ICP control, and warrants further study as to the dosage and timing of administration.

Synthesis of a conjugate vaccine composed of pneumococcus type 14 capsular polysaccharide bound to pertussis toxin

Type 14 is one of the common types isolated from patients of all ages with infections caused by Streptococcus pneumoniae. Its capsular polysaccharide (Pn14) is composed of a neutrally charged tetrasaccharide repeat unit. Pn14 does not elicit protective levels of antibodies in infants and children and is a less than optimal immunogen of the 23-valent vaccine for adults. Pertussis toxin (PT) is both a virulence factor and protective antigen of Bordetella pertussis: it is not soluble at neutral pH and forms insoluble complexes with acidic polysaccharides. Both Pn14 and PT are potential components of vaccines for infants and children. Accordingly, a synthetic scheme was devised to prepare a conjugate of Pn14 and PT. An adipic acid hydrazide derivative of Pn14 was bound to PT at pH 3.9 by carbodiimide-mediated condensation. The conjugation procedure inactivated the PT as assayed by CHO cell and histamine-sensitizing activity. The Pn14-PT conjugate elicited antibodies in mice to Pn14 at levels estimated to be protective in humans and elicited neutralizing antibodies to PT. We plan to evaluate Pn14-PT clinically.