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Biomedical subjects

M M Cohen

Publications and source records attributed to M M Cohen.

At least 163 records · Page 9Linked to original sources
PubMed1994

Loop ileostomy for temporary fecal diversion.

The aim of this study was to prospectively assess the morbidity of creating and closing loop ileostomies in a consecutive series of patients having an ileoanal pouch procedure. Between 1983 and 1991, 203 patients had loop ileostomies created for temporary fecal diversion after an ileoanal pouch procedure. There was one death as a result of liver failure. One patient developed a persistent pouch-vaginal fistula that resulted in pouch excision. The remaining 201 patients had their ileostomies closed at a mean time of 10 weeks after the primary procedure. Only 7% needed surgery to correct ileostomy-related problems. After ileostomy closure, complications were noted in only 2% of patients. Loop ileostomy is easy to create and provides highly effective fecal diversion, which decreases the incidence of and mitigates the serious sequelae of pouch sepsis. Closure is simple, does not require a laparotomy, and is associated with few complications. Our experience with loop ileostomy for temporary fecal diversion after an ileoanal pouch procedure has been favorable. The loop ileostomy may be the stoma of choice for most clinical situations in which temporary fecal diversion is indicated.

Adenomatous Polyposis Coli↗
PubMed1994

Visual, orthographic, phonological, and lexical influences in reading.

The fuzzy logical model of perception (FLMP), used as a framework to analyze phenomena in reading, asserts that there are multiple influences on reading performance. Experiments on the dynamic interaction of letter information and orthographic context are presented. Previous results have supported the FLMP over a variety of interactive activation models. These findings indicated that lateral masking and the time course of processing must be accounted for in the theoretical prediction of letter and word recognition. A new finding is that the word superiority effect is not influenced by the nature of the backward masking stimulus, nor is it diminished with letter and word masks, contrary to the predictions of several extant explanations. The FLMP is extended to account for reaction time in reading. Perceptual recognition, naming, and lexical decision tasks reflect the influence of multiple sources of information. These include orthographic structure, spelling-to-speech correspondences, and word frequency. Reading can be productively analyzed as a prototypical pattern recognition situation in which the reader exploits multiple sources of information in perception and action.

Auditory Perception↗
PubMed1994

Critical respiratory events in the postanesthesia care unit. Patient, surgical, and anesthetic factors.

BACKGROUND: Previous studies have noted a high incidence of adverse outcomes in the postanesthesia care unit (PACU), but few have examined associated factors and patient outcomes. To determine the frequency of acute, unanticipated respiratory problems and to examine the associated patient, surgical, and anesthetic factors, we prospectively collected preoperative, intraoperative, and postoperative data on 24,157 consecutive PACU patients who received a general anesthetic during a 33-month period. METHODS: A PACU critical respiratory event (CRE), was defined as any unanticipated hypoxemia (hemoglobin oxygen saturation < 90%), hypoventilation (respiratory rate < 8 breaths/min or arterial carbon dioxide tension > 50 mmHg) or upper-airway obstruction (stridor or laryngospasm) requiring an active and specific intervention (ventilation, tracheal intubation, opioid or muscle relaxant antagonism, insertion of oral/nasal airway or airway manipulation). These problems were documented by PACU nurses whereas data on case-mix, surgical factors, and intraoperative management were retrieved from the anesthetic record. Significant patient, surgical, and anesthetic factors were identified by logistic regression analysis. Other morbidity experienced by patients with a CRE was also noted. RESULTS: For patients given general anesthesia the risk of a CRE was 1.3% (hypoxemia 0.9%, hypoventilation 0.2%, airway obstruction 0.2%). Preoperative factors that increase risk were age > 60 yr, male gender, diabetes, and obesity (P < 0.05). Patients who underwent operative procedures on an emergency basis and whose operation was longer than 4 h were also at increased risk, but those undergoing perineal procedures were at lower risk (P < 0.05). Anesthetic risk factors (P < 0.05) included opioid premedication (relative odds 1.8), sedatives preoperatively (2.0), fentanyl > 2.0 micrograms.kg-1.h-1 as the sole opioid (1.9), fentanyl used in combination with morphine (1.6) and atracurium > or = 0.25 mg.kg-1.h-1 (2.2). Patients in whom anesthesia was induced with thiopental (relative odds 2.5), compared with those who received propofol for induction, were also at increased risk of a CRE. Patients with a CRE stayed longer in PACU, had higher rates of unanticipated admissions to the intensive care unit and were more likely to have PACU cardiac problems (P < 0.01). CONCLUSIONS: A CRE is relatively rare. Multiple patient and surgical factors and specific aspects of anesthetic management are associated with the occurrence of a CRE in the PACU.

Airway Obstruction↗
PubMed1994

Complex chromosomal rearrangements: some breakpoints may have cellular adaptive significance.

Cytogenetic study of a 3-year-old girl with developmental delay and some minor abnormalities revealed a complex chromosome rearrangement (CCR) involving seven chromosomes with eight breakpoints, leading to monosomy of segment 5q15-q22. According to breakpoint distribution, CCRs may be classified as those with primary intrachromosomal abnormalities (including inversions, insertions, duplications, etc.) and those without them. Only the latter group of CCRs was used in this analysis. Comparison of theoretical and observed breakpoint distributions in 33 cases demonstrated that recurrent involvement of some chromosome(s) ("re-entry") occurs more frequently than expected. One possible explanation for this observation suggests that the initial event leads to an unstable provisional rearrangement, and subsequent breaks are necessary to stabilize the karyotype.

Child, Preschool↗
PubMed1994

Assessing discomfort after anaesthesia: should you ask the patient or read the record?

OBJECTIVE: To assess the quality of anaesthesia care from the patients' viewpoint compared with the hospital record. DESIGN: Prospective study during 1988-9. SETTING: Four teaching hospitals (A-D) in Canada. PATIENTS: 15,960 inpatients receiving anaesthetic requiring at least an overnight stay, for whom an interview and review of hospital records within 72 hours of surgery were complete. MAIN MEASURES: Rates of postoperative symptoms of discomfort (nausea or vomiting, headache, back pain, sore throat, eye symptoms, and tingling) according to the hospital record versus interview and the relation between symptoms and patients' satisfaction with the anaesthetic experience. RESULTS: The preparation of completed interviews ranged from 31.0% to 72.7%, owing mainly to patients discharge (hospitals A and B) and severity of illness (C and D). Interviewed patients were similar to all inpatients in the hospitals but were younger and healthier and more had had effective operations and were general surgical than cardiovascular or neurosurgical patients. In all, 26% to 46% of patients at the four hospitals reported at least one symptom of discomfort. Agreement between interviews and hospital records was low, symptoms being more commonly reported by interview than in the record (for example, headache was reported for 5.8%-17% of patients compared with 0.3%-3.0% in hospital records). After controlling for case mix patients who reported at least one symptom were 2.91 times (95% confidence interval 1.89 to 4.50) more likely to be dissatisfied with their anaesthetic care than patients who did not. CONCLUSIONS: Anaesthesia services are typically neglected in studies of hospital quality, yet patients express considerable anxiety about anaesthetic care. Monitoring and recording patients' discomfort clearly need to be improved if the quality of anaesthesia is to be properly evaluated.

Adult↗
PubMed1994

The postoperative interview: assessing risk factors for nausea and vomiting.

Most studies of postoperative nausea and vomiting have concentrated on single etiologic factors and have not detailed the method of assessing these symptoms. This study used postoperative interview data from patients at four teaching hospitals during 1988-89, to determine 1) risk factors for nausea/vomiting, 2) whether the type of surgery affected the rate of nausea/vomiting among female patients, 3) whether differences in rates across hospitals were due to differences in patient case-mix, and 4) whether there were differences in the rate of nausea/vomiting among the patients of individual anesthesiologists. Research nurses performed 16,000 interviews (59% of all inpatients) from a closed-question standardized format. With a multiple logistic regression that controlled simultaneously for all risk factors, factors associated with increased risk for nausea/vomiting for all patients included younger age, female, lower physical status score, no preoperative medical conditions, nonsmokers, elective procedures, longer duration of anesthesia, inhaled anesthetics, use of intraoperative opioids, and gynecologic or ophthalmologic operations. Among women, risk factors were similar, with minor gynecologic surgery associated with increased risk (relative odds = 2.30). We found marked variations in the rate of nausea/vomiting across hospitals (range, 39% to 73%), and these variations were not explained by the case-mix of patients. The rate of nausea/vomiting varied substantially across anesthesiologists in each hospital and the differences were not explained by differences in the patients they managed. Thus in the time period immediately preceding the introduction of newer antiemetic drugs, we found that the rates of this common problem were persistently high as perceived from the patients' point of view.

Adult↗
PubMed1994

The premature infant: anesthesia for cesarean delivery.

The influence of anesthetic technique (general [GA] versus epidural [EPI]) on neonatal outcome was assessed for singleton infants of gestational age 32 wk or less, delivered by cesarean section. Neonates were identified from a prospectively collected perinatal database from 1986 to 1991. The independent effect of anesthetic technique on low 1-min Apgar scores after controlling for other risk factors was assessed by ordinal logistic regression. Among the 509 infants studied, 30% had Apgar scores of 0 to 3 at 1 min and 5.9% at 5 min. Among infants delivered with GA, 46.4% had low 1-min and 10.1% had low 5-min Apgar scores as compared to 22.0% and 3.8% for EPI. GA as compared to EPI was associated with higher risk of low (0-3) 1-min score after controlling for confounding factors (relative odds = 2.92, [1.99, 4.27 95% confidence intervals]). Other factors significantly related to low 1-min Apgar scores included malpresentation, maternal diabetes, primiparity, low gestational age, and associated neonatal outcomes (presence of respiratory distress syndrome and intraventricular hemorrhage). When there is a choice to be made in cesarean delivery of the premature infant, EPI is associated with higher 1- and 5-min Apgar scores compared to GA.

Anesthesia, Epidural↗
PubMed1994

The possible role of nystagmus in motion sickness: a hypothesis.

An alternative hypothesis to that provided by conflict theory is formulated to account for motion sickness. The new approach is predicted on the oculocardiac reflex (i.e., bradycardia produced by extra-ocular muscle traction) (18) and empirical evidence that retrobulbar anesthesia significantly lowers the incidence of emesis after strabismus surgery (14). Eye muscle traction is presumed to elicit afferent signals that ultimately stimulate the vagus nerve (15). The same neuromotor sequence is presumed to occur during reflexive eye movements under vestibular control and during more complicated combinations of reflexive and voluntary eye movements. It is proposed that the blocking of afferent signals from extra-ocular muscle in an otherwise intact vestibulo-ocular system will eliminate the signs and symptoms of motion sickness normally produced in a provocative environment.

Eye Movements↗
PubMed1993

Holoprosencephaly and primary craniosynostosis: the Genoa syndrome.

We report on 2 sibs with holoprosencephaly of the semilobar type, unusual facial appearance not diagnostic of holoprosencephaly, and primary craniosynotosis involving the coronal and lambdoid sutures. The condition represents a newly recognized syndrome, possibly having autosomal recessive inheritance.

Abnormalities, Multiple↗
PubMed1993

Another postnatal-onset obesity syndrome.

We describe an apparently newly recognized postnatal-onset obesity syndrome with short stature, mental deficiency, hypogonadism, micropenis, contractures of the fingers, and cleft lip-palate. Comparison is made with other postnatal-onset obesity syndromes, particularly Vasquez syndrome and Urban syndrome. The cause of our patient's syndrome is unknown at present. We encourage the reporting of other cases to help clarify whether our patient represents a separate entity.

Adult↗
PubMed1993

Sutural biology and the correlates of craniosynostosis.

The purpose of this paper is to provide a new perspective on craniosynostosis by correlating what is known about sutural biology with the events of craniosynostosis per se. A number of key points emerge from this analysis: 1) Sutural initiation may take place by overlapping, which results in beveled sutures, or by end-to-end approximation, which produces nonbeveled, end-to-end sutures. All end-to-end sutures occur in the midline (e.g., sagittal and metopic) probably because embryonic biomechanical forces on either side of the initiating suture tend to be equal in magnitude. A correlate appears to be that only synostosed sutures of the midline have pronounced bony ridging. 2) Long-term histologic observations of the sutural life cycle call into question the number of layers within sutures. The structure varies not only in different sutures, but also within the same suture over time. 3) Few, if any, of the many elegant experimental research studies in the field of sutural biology have increased our understanding of craniosynostosis per se. An understanding of the pathogenesis of craniosynostosis requires a genetic animal model with primary craniosynostosis and molecular techniques to understand the gene defect. This may allow insight into pathogenetic mechanisms involved in primary craniosynostosis. It may prove to be quite heterogeneous at the basic level. 4) The relationship between suture closure, cessation of growth, and functional demands across sutures poses questions about various biological relationships. Two conclusions are provocative. First, cessation of growth does not necessarily, or always lead to fusion of sutures. Second, although patent sutures aid in the growth process, some growth can take place after suture closure. 5) In an affected suture, craniosynostosis usually begins at a single point and then spreads along the suture. This has been shown by serial sectioning and calls into question results of studies in which the affected sutures are only histologically sampled. 6) Craniosynostosis is etiologically and pathogenetically heterogeneous. Known human causes are reviewed. Is craniosynostosis simply normal suture closure commencing too early?(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

Growth pattern in the Apert syndrome.

In this paper, we demonstrate that a discernible and unique growth pattern characterizes the Apert syndrome. The keys to understanding Apert newborn measurement values are brain size and cranial configuration. Both true megalencephaly and coronal synostosis are present at birth. Thus, the head is unusually heavy and the cranium is disproportionately high. Mean newborn length and weight are above the normal 50th centile. Of our newborn patients, 16% exceeded 4,000 g in weight. Preterm infants were appropriate or slightly large for gestational age. A biphasic linear growth pattern was found. In childhood, deceleration of linear growth occurs so that most values fall between the 5th and 50th centiles. From adolescence to adulthood, deceleration becomes more pronounced. This 2-step linear growth deceleration results in large measure from rhizomelic shortness of the lower limbs. Puberty takes place within the normal time frame. Although a disproportionate amount of the megalencephaly accounts for the dramatic increase in head height, the widely patent midline calvarial defect, allowing the brain to expand anteriorly into the metopic area, and some increase in the head breadth permit the mean head circumference at birth to normalize slightly above the 50th centile. During the growth period, the head circumference was studied in surgically unoperated Apert patients from the 1960s and earlier. The natural history of the growing cranium consists of gradual deceleration in head circumference from slightly above the 50th centile at birth to within or at -2 SD later on.

Acrocephalosyndactylia↗
PubMed1993

Skeletal abnormalities in the Apert syndrome.

This paper reports on skeletal abnormalities in 38 patients with Apert syndrome. Analysis includes alterations in the shoulders, humeri, elbows, hips, knees, rib cage, and spine (except the cervical spine). Some patients had subacromial dimples and elbow dimples during infancy. Mobility at the glenohumeral joint was limited. Progressive limitation in abduction, forward flexion, and external rotation with growth was virtually a constant finding. The acromioclavicular joint was prominent and sometimes had an angular, pointed appearance clinically. This was often associated with atrophic musculature and winging of the scapulae. Limited elbow mobility was common and usually mild in degree. Decreased elbow extension was most often found with decreased flexion, pronation, and supination occurring less frequently. Limited elbow mobility did not change significantly with growth in contrast to the increasing severity observed in the shoulder joint. Short humeri were a constant finding beyond infancy and genua valga of mild degree were present in many cases. Radiographic examination strongly suggests that the Apert syndrome is characterized by a multiple epiphyseal dysplasia. We found delay in appearance of postnatal ossification centers, particularly in the humeral head, greater tuberosity, capitulum, and radial head. Subsequently, these bones became abnormal in shape. Glenoid dysplasia was observed consistently. The neck of the scapula was very short or absent and the inferior margin of the glenoid cavity was poorly demarcated from the infraglenoid tubercle. The humeral head became oblong in shape with relative prominence of the greater tuberosity which compromised abduction. In the elbow, the capitulum was often small and the radial head was flat in many instances.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrocephalosyndactylia↗
PubMed1993

Saethre-Chotzen syndrome with familial translocation at chromosome 7p22.

Chromosome analysis of a male infant and his mother with Saethre-Chotzen syndrome demonstrated an apparently balanced translocation, t(2;7)(p23;p22). This association lends support to localization of the gene for Saethre-Chotzen syndrome to the 7p2 region and supports further involvement of gene(s) in the 7p22 region.

Acrocephalosyndactylia↗
PubMed1993

Proteus syndrome: clinical evidence for somatic mosaicism and selective review.

I report 2 unusual cases of Proteus syndrome that support the concept of somatic mosaicism. In one patient, a huge connective tissue nevus covered the chest and abdomen and hyperostoses of the calvaria were observed. In the other patient, linear verrucous epidermal nevi, epibulbar dermoids, and hyperostoses were found. No enlargement of the limbs or digits occurred and the plantar surfaces of the feet were normal. Selective aspects of Proteus syndrome not previously reviewed are also presented including: uncommon neoplasms; pulmonary and renal abnormalities; brain malformations; facial phenotype associated with seizures and severe mental deficiency; and types of abnormal growth in the craniofacial skeleton.

Brain↗
PubMed1993

Compromise of the spinal canal in Proteus syndrome.

We report on 2 children with spinal stenosis and neurologic sequelae. They illustrate the 2 ways in which spinal compromise may develop in Proteus syndrome--vertebral anomalies or tumor infiltration. In one patient, spinal stenosis resulted from an angular kyphoscoliosis. In the other, cord compression resulted from infiltration of a paraspinal, intrathoracic angiolipoma.

Angiolipoma↗