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M M Cohen

Publications and source records attributed to M M Cohen.

At least 145 records · Page 8Linked to original sources
PubMed1995

A population-based health information system.

The authors introduce the Population Health Information System, its conceptual framework, and the data elements required to implement such a system in other jurisdictions. Among other innovations, the Population Health Information System distinguishes between indicators of health status (outcomes measures) and indicators of need for health care (socioeconomic measures of risk for poor health). The system also can be used to perform needs-based planning and challenge delivery patterns.

Canada↗
PubMed1995

Measuring the health of the population.

A set of 102 population-based indicators was developed from multiple administrative data sources; these indicators were used to compare the health status of 1 million Manitoba residents across eight administrative regions for 1 year. Marked variations in health status were shown. Despite theoretically equal access to care in a universally insured system and high rates of utilization of hospital and physician services, residents of Manitoba's two northern, more remote regions scored most poorly--consistently and with statistical significance--across a variety of health status indicators. The strength of the various indicators was evaluated, and premature mortality emerged as the most useful "flagship" indicator for future analyses. Indicators that purport to be sensitive to how well a health care system is performing showed patterns similar to those derived from more classic measures (eg, mortality, low birth weight). Furthermore, the "system sensitive indicators" did not appear to be sufficiently independent of utilization biases.

Adolescent↗
PubMed1995

Hypothesis: patient with possible disturbance in programmed cell death.

Programmed cell death is a physiological process in mammalian development by which specific types of cells are eliminated, and, hence, is of fundamental importance in normal human embryogenesis. A patient is described with multiple congenital anomalies that may be explained by a disturbance of programmed cell death. Anomalies included macrocephaly, hypoplastic lacrimal ducts, narrow external ear canals, pharyngeal mucous membrane fold, unilateral cryptorchidism, cord-like vasa deferentia, and complete cutaneous syndactyly of the hands and feet.

Abnormalities, Multiple↗
PubMed1995

Cross-linguistic comparisons in the integration of visual and auditory speech.

We examined how speakers of different languages perceive speech in face-to-face communication. These speakers identified synthetic unimodal and bimodal speech syllables made from synthetic auditory and visual five-step /ba/-/da/ continua. In the first experiment, Dutch speakers identified the test syllables as either /ba/ or /da/. To explore the robustness of the results, Dutch and English speakers were given a completely open-ended response task. Tasks in previous studies had always specified a set of alternatives. Similar results were found in the two-alternative and open-ended task. Identification of the speech segments was influenced by both the auditory and the visual sources of information. The results falsified an auditory dominance model (ADM) which assumes that the contribution of visible speech is dependent on poor-quality audible speech. The results also falsified an additive model of perception (AMP) in which the auditory and visual sources are linearly combined. The fuzzy logical model of perception (FLMP) provided a good description of performance, supporting the claim that multiple sources of continuous information are evaluated and integrated in speech perception. These results replicate previous results found with English, Spanish, and Japanese speakers. Although there were significant performance differences, the model analyses indicated no differences in the nature of information processing across language groups. The performance differences across languages were caused by information differences due to different phonologies in Dutch and English. These results suggest that the underlying mechanisms for speech perception are similar across languages.

Adult↗
PubMed1995

Effects of optical pitch on oculomotor control and the perception of target elevation.

In two experiments, we used an ISCAN infrared video system to examine the influence of a pitched visual array on gaze elevation and on judgments of visually perceived eye level. In Experiment 1, subjects attempted to direct their gaze to a relaxed or to a horizontal orientation while they were seated in a room whose walls were pitched at various angles with respect to gravity. Gaze elevation was biased in the direction in which the room was pitched. In Experiment 2, subjects looked into a small box that was pitched at various angles while they attempted simply to direct their gaze alone, or to direct their gaze and place a visual target at their apparent horizon. Both gaze elevation and target settings varied systematically with the pitch orientation of the box. Our results suggest that under these conditions, an optostatic response, of which the subject is unaware, is responsible for the changes in both gaze elevation and judgments of target elevation.

Adolescent↗
PubMed1995

Analysis of phenotypic features and FGFR2 mutations in Apert syndrome.

A phenotypic and genotypic survey was conducted on 36 Apert syndrome patients. In all but one patient, an FGFR2 mutation, either S252W or P253R, was found in exon IIIa (exon U or 7). The frequency was 71% and 26%, for the mutations S252W and P253R, respectively. These mutations occur in the linker region between immunoglobulin-like domains II and III, which are involved in activation of the receptor by ligand binding and dimerization. The fact that one patient did not have a mutation in the same exon suggests further genetic heterogeneity in Apert syndrome. The frequencies of occurrence or means for measurements of 29 different clinical features (including severity of craniofacial features, syndactyly of the hands and feet, and multisystem involvement) were determined for all patients and for the two subgroups defined by their mutations. Comparison between the subgroups for the different clinical features was performed and suggested no statistically significant differences. These results are not unexpected, because the two common mutations for Apert syndrome alter FGFR2 at adjacent amino acids that are likely to have similar biological, and therefore phenotypic, consequences.

Acrocephalosyndactylia↗
PubMed1994

Variations in hysterectomy rates in Ontario: does the indication matter?

OBJECTIVES: To examine variations in rates of hysterectomy for the five main indications for the procedure in regions of Ontario. DESIGN: Cross-sectional population-based analysis of hospital discharge abstracts. SETTING: All acute care facilities in Ontario. PARTICIPANTS: All 65,599 women whose hospital record contained a procedure code indicating that a hysterectomy was performed between Apr. 1, 1988, and Mar. 31, 1991. Duplicate cases, records of cancelled procedures and nonresidents were excluded. MAIN OUTCOME MEASURES: Crude and age-adjusted rates of hysterectomy, by indication, for each region of Ontario. RESULTS: Five indications accounted for more than 80% of hysterectomies performed. The median age-adjusted rate of hysterectomy for Ontario regions during the study period was 6.25 per 1000 women, with a 2.7-fold variation among regions. The regions with rates of hysterectomy in the highest quartile tended to be rural, and those with rates in the lowest quartile tended to be urban areas with teaching hospitals. When rates of hysterectomy for specific indications were examined, they showed substantial variations among regions in the rate of the procedure for menstrual hemorrhage (18-fold variation), uterine prolapse (9.3-fold) and endometriosis (6.3-fold). A smaller but still significant variation was shown in the rate of hysterectomy for leiomyoma (2.3-fold). Regional variation in the rate of hysterectomy for cancer (2.5-fold) was not statistically significant. CONCLUSIONS: There are large interregional variations in rates of hysterectomy, especially for indications that are more discretionary than others (i.e., menstrual hemorrhage, uterine prolapse and endometriosis) and less variation in rates when treatment options and diagnosis are clear-cut. This result suggests the need for more definitive practice guidelines on treatment of the indications for which the rate is more variable.

Adult↗
PubMed1994

Regional Proteus syndrome and somatic mosaicism.

We report on a patient with regional manifestations of Proteus syndrome. Major findings included multiple hyperostoses of the calvaria, facial bones, and mandible. Additionally, the patient had a scleral tumor. This lends further support to the hypothesis of somatic mosaicism as a cause of Proteus syndrome. Because mosaic distribution of lesions is variable in extent, criteria for the diagnosis of Proteus syndrome should be loose rather than overly rigid even though patients with limited regional involvement may be particularly difficult to diagnose.

Child↗
PubMed1994

Determination of gene dosage by a quantitative adaptation of the polymerase chain reaction (gd-PCR): rapid detection of deletions and duplications of gene sequences.

Screening methods based on the polymerase chain reaction (PCR), such as denaturing gradient gel electrophoresis, single-stranded conformational polymorphism, and heteroduplex analysis, are powerful tools for the detection of point mutations as well as small deletions and insertions, but are unable to detect heterozygous deletions or duplications of exons, genes, or chromosomes. We now report a PCR-based approach, designated gene dosage-PCR (gd-PCR), that allows rapid screening for heterozygous deletions and duplications of genes or exons. Gene dosage-PCR is a quantitative method in which two in vitro synthesized DNA internal standards are coamplified with the genomic DNA sample, one corresponding to the gene of interest (test sequence) and the other to a reference (disomic) gene (reference sequence). Both internal standards are designed to be amplified with the same primer pairs and with efficiencies similar to those of their genomic DNA counterparts, yielding PCR products slightly smaller than those derived from genomic DNA. Amplification of approximately equimolar amounts of the two internal standards and genomic DNA, in the presence of [32P]dCTP, results in four radiolabeled PCR products; after electrophoresis and quantification of the products, gene dosage is easily calculated. For validation, genomic DNA from 56 subjects, 28 with cytogenetically documented Down syndrome (trisomy 21) and 28 controls that were disomic for chromosome 21, was assayed. Using the beta-amyloid precursor protein gene (APP: chromosome 21q21) as the test sequence, control subjects had an adjusted mean gene dose of 2.00 +/- 0.29, while subjects with Down syndrome had a mean gene dose of 3.05 +/- 0.27.(ABSTRACT TRUNCATED AT 250 WORDS)

Amnion↗
PubMed1994

Alpha 1-antitrypsin deficiency. Impact of genetic discovery on medicine and society.

An increasing body of molecular information resulting from advances in basic research is being incorporated into clinical practice by medical genetics. The process by which these research advances progress from the laboratory to the bedside and their medical, social, and legal impact is a topic of intense current interest. Some authors have claimed that new genetic information may lead to discrimination in insurance and employment; change the way courts allocate responsibility for injury and resultant damages; and be inappropriately interpreted by the medical profession. To address some of these issues, we chose, as a model, to review alpha 1-antitrypsin deficiency, described over 30 years ago. At this time, such concerns with respect to alpha 1-antitrypsin deficiency have not yet been realized, perhaps for the following reasons: (1) knowledge of alpha 1-antitrypsin deficiency, while common among geneticists and pulmonologists, has not been well disseminated in the medical community; (2) insurers, employers, lawyers, and judges are not generally aware of the deficiency and its implications; (3) insurers, if they are aware of the deficiency, have not found it cost-effective to screen for the condition; and (4) in the legal context, case law involving other types of preexisting conditions is being applied to genetic predispositions.

Biomedical Research↗
PubMed1994

Genetic heterogeneity among craniosynostosis syndromes: mapping the Saethre-Chotzen syndrome locus between D7S513 and D7S516 and exclusion of Jackson-Weiss and Crouzon syndrome loci from 7p.

Saethre-Chotzen, Crouzon, and Jackson-Weiss syndromes are craniosynostotic autosomal dominant conditions with a wide variability in expression. Saethre-Chotzen has been mapped to chromosome 7p by L. A. Brueton et al. (1992, J. Med. Genet. 29: 681-685), the Greig cephalopolysyndactyly gene was identified at 7p13 by A. Vortkamp et al. (1991, Nature 352: 539-540), and many cases of craniosynostosis have been associated with 7p deletions. We confirmed linkage of the Saethre-Chotzen syndrome locus to chromosome 7p. The tightest linkage was to locus D7S493 (Z = 5.04, theta = 0.00), and linkage and haplotype analyses refined the location of the gene to the region between D7S513 and D7S516. Jackson-Weiss and Crouzon syndrome loci were analyzed using markers spanning the entire 7p arm and were excluded, proving that they are nonallelic to Saethre-Chotzen, Greig cephalopolysyndactyly, and the del(7p) syndromes.

Abnormalities, Multiple↗
PubMed1994

Complex karyotypic mosaicism as a result of non-disjunction and subsequent centromere fission.

Karyotypic discrepancy among four different cell types is described in tissues derived from a pregnancy terminated because of chromosomal anomalies. Chorionic villus cells demonstrated 46,XX (direct preparation) and 46,XX/47,XX,+mar1 (cultured cells) karyotypes, while fetal skin fibroblasts had a karyotype of 47,XX,+18 and the placenta showed a triple mosaicism of 47,XX,+18/47,XX,+mar1/48,XX,+18,+mar2. The origin of this complex chromosomal distribution and its significance are discussed in comparison with findings in similar cases.

Abortion, Induced↗
PubMed1994

Survival following surgical treatment of gastric cancer. A challenge for the community endoscopist.

The management of 124 patient diagnosed with adenocarcinoma of the stomach from 1971 to 1990 was reviewed. Early gastric cancer increased from 0% to 9% of the cases between the first and last quarter of the study. Proximal gastric cancer similarly increased from 8% in the first decade to 29% of all cases diagnosed during the second decade of the study. Follow-up information was available for all patients. Nineteen patients (15%) had no operation and two survived more than 2 years. Twelve patients had a surgical biopsy only and four had a palliative bypass; none survived 2 years. Eighty-six patients (69%) had a surgical resection with a 30-day operative mortality of 8% and a 5-year survival of 17%. Prognosis was significantly better for patients with T-1 and T-2 tumors and for those with distal cancers. Patients with early gastric cancer had 67% 5-year survival. These data should encourage efforts to improve the diagnosis of early gastric cancer.

Adenocarcinoma↗
PubMed1994

The airway: problems and predictions in 18,500 patients.

The purpose of this study was to describe methods, risk factors, and outcomes of airway management in all patients (obstetrics excluded) attended by anaesthetists over 27 months. Preoperatively, anaesthetists recorded patient factors and assessed four airway characteristics. Methods of tracheal intubation and ease of direct laryngoscopy following general anaesthesia (easy, awkward, difficult) were noted. Factors predictive of poor outcome and the value of the preoperative airway examination were determined. For 18,205 patients following a direct laryngoscopy, (GA), tracheal intubation was difficult (> 2 laryngoscopies) in 1.8% and awkward (< or = 2 laryngoscopies) in 2.5%. This approach was a failure in 0.3%, and surgery was postponed in 0.05%. However, an alternative approach to direct laryngoscopy, (GA) was the first choice in 353 patients. Risk factors for difficult tracheal intubation included male sex, age 40-59 yr and obesity (P < or = 0.01). For direct laryngoscopy, (GA), airway characteristics predictive of difficult tracheal intubation were decreased mouth opening (relative risk 10.3), shortened thyromental distance (9.7), poor visualization of the hypopharynx (4.5), and limited neck extension (3.2), any two (7.6) and more than two (9.4) (P < 0.01). For 1,856 patients (10.0%) where at least one airway characteristic was abnormal, a direct laryngoscopy, (GA) resulted in 8.3% awkward and 6.0% difficult tracheal intubations. For patients with no abnormal airway characteristics, tracheal intubation was easy in 96.3%. Where tracheal intubation was difficult, 34.3% of patients had one or more abnormal airway characteristics preoperatively. Patients with difficult tracheal intubation had an increased rate of desaturation (< 90%), hypertension (> 200 mm Hg) and dental damage on induction of anaesthesia. It is concluded that difficult tracheal intubations occurred infrequently but were associated with increased morbidity. Patient factors and four physical airway characteristics were useful predictors but limited in identifying all problems.

Adult↗