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Biomedical subjects

M M Cohen

Publications and source records attributed to M M Cohen.

At least 109 records · Page 6Linked to original sources
PubMed1996

Suture formation, premature sutural fusion, and suture default zones in Apert syndrome.

On the basis of our studies, we postulate that suture formation in Apert syndrome is related to the relative maturity of abutting calvarial bones. The fused coronal suture, a consistent manifestation at birth, develops first because the ossification centers of the frontal and parietal bones are in intimate contact early during intrauterine life. Calvarial immaturity and the megalencephalic brain characteristic of the Apert syndrome appear to work in concert to produce a widely patent midline calvarial defect extending from the glabella to the posterior fontanelle. Because sagittal growth in the coronal sutures cannot take place, the megalencephalic brain grows upward and laterally, and bulges forward through the midline defect. The defect fills in by coalescence of bony islands without proper suture formation because the gap to be bridged is so great that the time window for developing sutural interdigitations may have closed. Other sutures, such as the lambdoid, squamosal, and sphenotemporal, develop with normal interdigitations because abutting bone margins are in close enough proximity to permit suture formation.

Acrocephalosyndactylia↗
PubMed1996

Hunter-McAlpine craniosynostosis phenotype associated with skeletal anomalies and interstitial deletion of chromosome 17q.

Hunter-McAlpine syndrome is an autosomal dominant disorder consisting of variable manifestations including craniosynostosis, almond-shaped palpebral fissures, small mouth, mild acral-skeletal anomalies, short stature, and mental deficiency. We report on a 9-year-old boy with this phenotype with more severe skeletal abnormalities than previously described. Chromosomes showed del(17)(q23.1-->q24.2); the more severe phenotype may be explained by the deletion. The deletion also suggests the possibility that the gene for Hunter-McAlpine syndrome might map to that region.

Abnormalities, Multiple↗
PubMed1996

Has laparoscopic cholecystectomy changed patterns of practice and patient outcome in Ontario?

OBJECTIVE: To examine the effect of the introduction of laparoscopic cholecystectomy (LC) on patterns of practice (number of cholecystectomy procedures, case-mix and length of hospital stay) and patient outcomes in Ontario. DESIGN: Cross-sectional population-based time trends using hospital discharge data. SETTING: All acute care hospitals in Ontario where cholecystectomy was provided. PATIENTS: All 119,821 Ontario residents who underwent cholecystectomy between 1989-90 and 1993-94. After exclusions (initial bile duct exploration, cancer, incidental cholecystectomy, or missing codes for age, sex or residence) 108,442 patients remained. OUTCOME MEASURES: Number of cholecystectomy procedures, proportion of patients with acute or chronic gallstone disease, length of hospital stay, and rates of death, readmission, and bile duct injury and other in-hospital complications after cholecystectomy by year. RESULTS: The number of cholecystectomy procedures increased by 30.4% between 1989-90 and 1993-94. The number of patients with chronic gallstone disease increased by 33.6%, and the number who underwent elective surgery increased by 48.3%. The proportion of procedures performed as LC increased from 1.0% in 1990-91 to 85.6% in 1993-94. Patients who received LC tended to be younger female patients with chronic gallstone disease with no coexisting conditions undergoing elective operations. The mean length of stay, adjusted for case-mix differences, was significantly lower in 1993-94 than in 1989-90 (2.6 days v. 7.5 days) (p < 0.05); the values for LC and open cholecystectomy in 1993-94 were 1.8 days and 7.3 days respectively. The decrease in the crude death rate over the study period (0.3% to 0.2%) was not significant (relative odds 1.10, 95% confidence interval [CI] 0.72 to 1.69). In 1993-94 the adjusted risk of readmission to hospital within 30 days was 1.38 (95% CI 1.19 to 1.58) as compared with 1989-90. Over the 5 years the rate of bile duct injuries tripled (0.3% in 1989-90 v. 0.9% in 1993-94). The adjusted risk of having at least one complication after cholecystectomy in 1993-94 was 1.90 (95% CI 1.75 to 2.07) as compared with 1989-90. CONCLUSIONS: LC has had a substantial effect on the number of cholecystectomy procedures performed, the type of patient having the gallbladder removed and the length of hospital stay. Death rates are unchanged, but the odds of readmission and in-hospital complications are both increased. Future research should be directed toward determining the reasons for the overall increase in rates, developing methods to reduce bile duct injuries and identifying other relevant outcomes, such as patient satisfaction with the procedure.

Adolescent↗
PubMed1996

Craniofrontonasal syndrome: study of 41 patients.

Of 41 patients with craniofrontonasal syndrome, 35 were female and 6 were male. Although most cases were sporadic, 7 familial instances were found. Craniofrontonasal syndrome represents a unique, incompletely understood X-linked disorder. Unusual manifestations in females included thick, wiry, and curly hair (49%), anterior cranium bifidum (6%), axillary pterygia (9%), unilateral breast hypoplasia (postpubertal; 11%), and asymmetric lower limb shortness (14%).

Adolescent↗
PubMed1996

Cerebrofaciothoracic syndrome.

We report on a patient with a large septum pellucidum, hypodensity of gray matter, hypertelorism, and costovertebral anomalies. Only 5 previous cases have been described with this distinctive phenotype. Autosomal recessive inheritance seems likely.

Abnormalities, Multiple↗
PubMed1996

Planned and unplanned postoperative admissions to critical care for mechanical ventilation.

PURPOSE: To determine which factors influence the clinician in choosing critical care admission and postoperative ventilation, we prospectively examined the incidence, timing, causes, and risk factors for admission to critical care for postoperative ventilation within 48 hr of a surgical procedure (excluding cardiac and neurosurgical). METHODS: Patients were categorized as: admission planned preoperatively; admission unplanned and identified in the OR (Operating Room) or PACU (Post Anaesthetic Care Unit); and admission unplanned, identified after PACU discharge. Rates of admission by category for those with specific preoperative and intraoperative characteristics were compared to those without the characteristics to determine risk factors for admission (P < 0.01). RESULTS: Only 329 of 15,059 cases (2.2%) had a critical care admission. Of these, 288 were planned, 31 identified in the OR or PACU, and 10 after PACU discharge. A respiratory aetiology was the reason for admission in 75% of unplanned cases. Preoperatively, age > or = 60 yr and common systemic illnesses (cardiac, renal, pulmonary) were markers for planned admission, but only positive HIV status was a risk factor for unplanned admission. The two main physiological features which identified all critical care admissions were haemoglobin oxygen saturation < 90% (preoperatively breathing room air and intraoperatively) and tachycardia during the operative period. Six of ten of the unplanned after PACU discharge patients underwent bronchoscopy with a neurolept analgesic technique. CONCLUSION: Postoperative admissions to a critical care unit, both planned and unplanned, are uncommon. This study has identified haemoglobin oxygen desaturation during the perioperative period and intraoperative tachycardia as important markers for all admissions to critical care.

Adult↗
PubMed1996

The incidence of airway problems depends on the definition used.

PURPOSE: Definitions currently used to describe airway difficulties are confusing, inconsistent, and may be misleading. To understand the "extent of the problem" better using three different definitions we examined the corresponding rates of airway difficulty in 3,325 consecutive adult patients who had direct laryngoscopy with tracheal intubation following induction of general anaesthesia. METHODS: Definitions were (i) poor view at laryngoscopy (GRADE 3-4) documented on modified diagrams of Cormack and Lehane; (ii) > or = 3 laryngoscopy attempts; and (iii) failure of direct laryngoscopy. The incidences of airway difficulty attributable to each definition were compared. RESULTS: For the three definitions rates varied, 10.1% for poor view, 1.9% > or = 3 laryngoscopies, and failure 0.1%. For patients with a GRADE 3-4 view, 15.8% required > or = 3 laryngoscopies, but for those with > or = 3 laryngoscopies, 84.1% had GRADE 3-4 view. All patients with failed laryngoscopy had > or = 3 laryngoscopies and a GRADE 4 view. CONCLUSION: This wide variation in defining the "extent of the problem" emphasizes the need for agreement of definitions and improved methods to document airway difficulties.

Female↗
PubMed1996

Using an alternative data source to examine randomization in the Canadian National Breast Screening Study.

Criticisms of the Canadian National Breast Screening Study (NBSS) assert that reported findings (more deaths in women aged 40-49 allocated to mammography versus no mammography and no difference in mortality between women who had mammography and physical examination versus physical examination alone for those aged 50-59) may be due to more women with prior breast disease being allocated to the mammography arms of the study. The possibility that allocation was not random was examined for NBSS participants in Manitoba, Canada, using health insurance data that were external to and independent of the NBSS. The study design consisted of a retrospective observation study using health insurance (claims) data to construct health histories of breast disease prior to NBSS entry. Self-reported breast disease from the NBSS entry questionnaires was compared to breast disease histories on the basis of health insurance claims. The setting consisted of one NBSS screening center in Winnipeg, Canada. The patient population consisted of 9477 women with at least one health insurance claim in the 24 months prior to NBSS entry. We determined the proportions of women within each study arm who had claims for breast disease, breast disease investigation, or xeromammograms in the 24 months prior to NBSS entry, and compared the proportion of women's self-reports of breast disease or xeromammography with the presence/absence of a claim prior to NBSS entry for breast disease or xeromammography. No significant differences in the proportion of women with prior histories of benign breast disease, investigation, or xeromammograms (p > 0.05) were found across the study arms. Nine women in the mammography group versus one in the no mammography group had one prior health insurance claim for breast cancer, but eight of these women had no subsequent claims for breast cancer. There were no differences across the study arms in the proportion of women who reported a prior history of breast disease or a prior xeromammogram for whom an insurance claim was found. Using data external to the NBSS for Manitoba participants, the study found no definitive evidence to support a nonrandom allocation of women with prior breast disease to the mammography arms of the study. However, generalizability to the other NBSS centers cannot be assured.

Adult↗
PubMed1996

Reminding and monitoring: new uses of administrative data for preventive care.

This article illustrates how administrative data can be used to improve population health in an environment of fiscal constraint. In our universal single-payer health system, health care providers submit standardized data. This allows provinces to create health information utilities that generate population-based data that can be used for research and health care delivery. Although more study is needed to determine the cost-effectiveness of using such data to raise the rates of primary and secondary prevention, it appears that appropriately designed information systems could improve population health with relatively little additional cost.

Aged↗
PubMed1996

A clinical study of the craniofacial features in Apert syndrome.

A clinical study of the craniofacial features in Apert syndrome is based on our experience with 136 cases. Characteristics included hyperacrobrachycephaly, steep wide forehead, flat occiput, common craniofacial asymmetry, ocular hypertelorism and proptosis, downslanting palpebral fissures, divergent upgaze and esotropic downgaze, a tendency towards large ears, and marked depression of the nasal bridge. The nose is short and wide with a bulbous tip, and the anterior facial height is reduced. Common features during infancy included horizontal grooves above the supraorbital ridges that disappear with age, a break in the continuity of the eyebrows, and a trapezoidal-shaped mouth at rest. Radiographic aspects of Apert syndrome were also assessed. Tables are provided which compare the craniofacial features of Apert and Crouzon syndromes.

Acrocephalosyndactylia↗
PubMed1996

Frontonasal dysplasia: analysis of 21 cases and literature review.

Twenty-one patients with frontonasal dysplasia were studied. A 2:1 male-to-female sex ratio and increased paternal and maternal ages at the time of conception were found. The significance is uncertain because of small sample size and lack of normal mean values for parental age in Brazil. Apparently, our series is the first to report macrocephaly (six cases). Our series also had a high frequency of patients with agenesis of the corpus callosum (12 cases), basal encephalocele (10 cases), lipoma of the corpus callosum (four cases), and mental deficiency (11 cases). Three patients had the combination of agenesis of the corpus callosum, mental deficiency, and micropenis. It is concluded that frontonasal dysplasia is pathogenetically heterogeneous, representing a regional defect which may not be a single developmental field or sequence. Causal genesis includes a dominantly inherited form, dup(2q), and autosomal recessive Shanske syndrome. Of unknown genesis are two subsets of frontonasal dysplasia patients: 1) the combination of agenesis of the corpus callosum, tibial hypoplasia, and hallucal duplication and 2) ophthalmofrontonasal dysplasia or oculoauriculofrontonasal dysplasia with associated ear tags and epibulbar dermoids.

Abnormalities, Multiple↗
PubMed1996

Fibroblast growth factor receptor 2 mutations in Beare-Stevenson cutis gyrata syndrome.

Beare-Stevenson cutis gyrata syndrome (MIM 123790) is an autosomal dominant condition characterized by the furrowed skin disorder of cutis gyrata, acanthosis nigricans, craniosynostosis, craniofacial dysmorphism, digital anomalies, umbilical and anogenital abnormalities and early death. Many of these features are characteristic of some of the autosomal dominant craniosynostotic syndromes. Mutations in Crouzon, Jackson-Weiss, Pfeiffer and Apert syndromes have been reported in the FGFR2 extracellular domain. In Crouzon syndrome patients with acanthosis nigricans, a recurrent mutation occurs in the transmembrane domain of FGFR3. We now describe the detection of FGFR2 mutations in the Beare-Stevenson cutis gyrata syndrome. In three sporatic cases, a novel missense mutation was found causing an amino acid to be replaced by a cysteine; two had the identical Ty375Cys mutation in the transmembrane domain and one had a Ser372Cys mutation in the carboxyl-terminal end of the linker region between the immunoglobulin III-like (Iglll) and transmembrane domains. In two patients, neither of these mutations were found suggesting further genetic heterogeneity.

Abnormalities, Multiple↗
PubMed1996

Cardiovascular events in the postanesthesia care unit: contribution of risk factors.

BACKGROUND: The purpose of this study was to determine the relationship of four postanesthesia care unit (PACU) cardiovascular events to long-term outcomes (unplanned critical care admission or mortality) and to evaluate the contribution of anesthetic management compared with other perioperative factors in predicting these events. METHODS: For patients admitted to the PACU after receiving general anesthesia (n = 18,380), the risk of long-term outcomes was examined for patients in the PACU with hypertension, tachycardia, bradycardia, or hypotension. Using logistic regression (P < 0.05), risk factors (grouped as patients, surgical, anesthetic, operating room observations, and other PACU observations) for each cardiovascular event were determined. For each factor grouping, the relative contributions to each cardiovascular event were compared using maximum likelihood chi-square analysis. RESULTS: Patients in the PACU with hypertension or tachycardia had more unplanned critical care admissions (2.6% and 4.0% vs. 0.2% for patients with no events) and greater mortality (1.9% and 2.3% vs. 0.3% and 0.4%) (P < 0.01). For PACU hypertension (rate 2.0%), age, smoking, renal disease, female gender, and angina were significant risk factors. For PACU tachycardia (0.9%), intraoperative tachycardia and dysrhythmia were the major contributors. Patient factors also increased the risk of bradycardia (2.5%); namely age, ASA physical status 1 or 2, and preoperative beta blocker therapy. For hypotension (2.2%), duration of surgery > 2 h, completion after 6 PM, and gynecologic intraabdominal procedures were significant risk factors. Compared to patient, surgical, intraoperative, or PACU observations, anesthetic factors studied (premedication, induction agent, ventilation, use of opioids) provided only a small contribution in predicting these events. CONCLUSIONS: Hypertension and tachycardia in the PACU, although infrequent, are associated with increased risk of unplanned critical care admission and mortality. Patient, surgical, intraoperative, or PACU observations contribute more to cardiovascular events in the PACU than do differences in anesthetic management identified in this study.

Anesthesia↗
PubMed1996

Changing anesthesiologists' practice patterns. Can it be done?

BACKGROUND: Because the ultimate purpose of new medical knowledge is to achieve improved health outcomes, physicians need to possess and use this knowledge in their practice. The authors introduced enhanced education and individualized feedback to reduce postoperative nausea and vomiting (PONV). The primary objective was to increase anesthesiologists' use of preventive measures to reduce PONV, and the secondary objective was to determine whether patient outcomes were improved. METHODS: After obtaining hospital ethics committee approval, the effect of education and feedback on anesthesiologist performance and the rate of PONV in major surgery elective inpatients during a 2-yr period was assessed. After baseline data collection (6 months), anesthesiologists at the study hospital received enhanced education (8 months) and individualized feedback (10 months). Parallel data collection was performed at a control hospital at which practice was continued as usual. The education promoted preventive measures (antiemetic premedication, nasogastric tubes, droperidol, metoclopramide). Individualized feedback provided the number of patients receiving promoted measures and the rate of PONV. The mean percentage of anesthesiologists' patients receiving at least one promoted measure and the rate of PONV were compared with baseline levels. RESULTS: At the study hospital, there was a significant increase in the mean percentage of the anesthesiologists' female patients receiving a preventive measure as well as a significant increase in the use of droperidol > or = 1 mg (P < 0.05) for all patients. The use of other promoted measures was unaffected. Absolute rates of PONV were unaffected at the study hospital until the post-feedback period (decrease of 8.8% between baseline and post-feedback (P = 0.015)). CONCLUSION: It was demonstrated that enhanced education and individualized feedback can change anesthesiologists' practice patterns. The actual benefit to patients from use of preventive measures was limited when used in the everyday clinical situation. Therefore, only modest decreases in PONV were achieved, despite the use of preventive measures.

Anesthesiology↗
PubMed1996

Perception of asynchronous and conflicting visual and auditory speech.

Previous research has shown that perceivers naturally integrate auditory and visual information in face-to-face speech perception. Two experiments were carried out to study whether integration would be disrupted by differences in the stimulus onset asynchrony (SOA), the temporal arrival of the two sources of information. Synthetic visible and natural and synthetic auditory syllables off/ba/, /va/, [symbol: see text]a/, and /da/ were used in an expanded factorial design to present all possible combinations of the auditory and visual syllables, as well as the unimodal syllables. The fuzzy logical model of perception (FLMP), which accurately describes integration, was used to measure the degree to which integration of audible and visible speech occurred. These findings provide information about the temporal window of integration and its apparent dependence on the range of speech events in the test.

Adult↗