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Biomedical subjects

M S Cohen

Publications and source records attributed to M S Cohen.

At least 37 records · Page 2Linked to original sources
PubMed2001

Closed reduction and percutaneous pinning of fractures of the proximal phalanx.

This study reports the results of 12 unstable extraarticular fractures of the proximal phalanx treated with transarticular intramedullary Kirschner wires. Early proximal interphalangeal joint motion was allowed and all patients achieved uneventful union, with an average total active motion of 265 degrees. Objective physical assessment revealed one significant flexion contracture, one flexor tendon adhesion and one significant rotational deformity. Excellent results were observed in ten of the 12 patients.

Adolescent↗
PubMed2001

Deviation of atrial septum primum in association with normal left atrioventricular valve size.

Deviation of atrial septum primum (DASP) is an unusual anatomic finding in patients with normal left atrioventricular valve size. To better describe this anomaly, we reviewed our echocardiographic database from January 1987 to May 1999. Twenty-four patients had DASP and a normal-sized left atrioventricular valve. Six had inferior DASP with common atrioventricular canal. Of these, 3 had evidence of left atrial outlet obstruction. Five survived surgical intervention with follow-up of 24 +/- 14 months. Seventeen patients had superoposterior deviation with the right pulmonary veins draining anomalously to the right atrium. Only 8 of 17 underwent surgical resection; none of the 17 have evidence for late development of obstruction. One patient had both inferior deviation and superoposterior DASP and underwent early successful repair. DASP occurs in patients with normal left atrioventricular valve size. Inferior DASP can result in left atrial outlet obstruction and requires surgical intervention. Superoposterior DASP carries less physiologic consequence. Echocardiography can distinguish this anomaly from other forms of left atrial obstruction.

Child, Preschool↗
PubMed2001

Risk of malignancy in thyroid incidentalomas identified by fluorodeoxyglucose-positron emission tomography.

BACKGROUND: Thyroid tumors often exhibit increased metabolic activity, as evidenced by enhanced glucose uptake on positron emission tomography (PET) with use of (18)F-fluorodeoxyglucose (FDG). The incidence of new thyroid lesions found on routine FDG-PET has not been previously reported. METHODS: A retrospective review of all patients who underwent FDG-PET imaging at our institution from June 1, 1996, through March 15, 2001, identified patients with a newly diagnosed thyroid lesion. Thyroid incidentaloma was defined as a thyroid lesion seen initially on FDG-PET in a patient without a history of thyroid disease. Available follow-up data were documented. RESULTS: One hundred and two of 4525 FDG-PET examinations (2.3%) demonstrated thyroid incidentalomas. Eighty-seven of 102 patients had no thyroid histology because of other malignancies. Fifteen patients had thyroid biopsy: 7 (47%) with thyroid cancer, 6 (40%) with nodular hyperplasia, 1 with thyroiditis, and 1 with atypical cells of indeterminate origin. The average standardized uptake values were higher for malignant compared with benign lesions. CONCLUSIONS: Thyroid incidentaloma identified by FDG-PET occurred with a frequency of 2.3%. Of the thyroid incidentalomas that underwent biopsy, 47% were found to be malignant. Given the risk of malignancy, patients with new thyroid lesions on PET scan should have a tissue diagnosis if it will influence outcome and management. Standardized uptake values may be helpful in predicting benign versus malignant histology.

Adult↗
PubMed2001

The collateral ligaments of the elbow: anatomy and clinical correlation.

Stability of the elbow is provided by the congruous nature of the bony articulations and the medial and lateral collateral ligament complexes. The medial ligament provides additional support to valgus stress. The lateral ligament prevents rotational instability between the distal humerus and the proximal radius and ulna. Collateral ligament insufficiency typically is posttraumatic and can occur on either side of the joint. An understanding of the normal anatomy is required to make the correct diagnosis and complete a successful surgical reconstruction.

Athletic Injuries↗
PubMed2001

Decompressive surgery for typical lumbar spinal stenosis.

Between 1991 and 1992, 103 consecutive patients (average age, 65 years) underwent decompressive surgery for treatment of typical lumbar spinal stenosis. Clinical results at 1-year followup revealed that four patients had revision surgery. At 2- to 5-years followup, there were no additional revision surgeries. Two patients underwent revision surgery for a deep infection, and two underwent revision surgery for a superficial infection. Outcome results showed that 77 patients completed the questionnaire, 15 were lost to followup and 11 died. Postoperative results showed that 64 of 77 patients had no or mild pain, 72 of 77 patients stated that they were satisfied or somewhat satisfied with their overall results of surgery, and 73 of 77 were satisfied with pain relief. Younger patients had greater improvement in function and a greater reduction in severity scores. However, satisfaction was similar in both groups. Survivorship results (failure was revision surgery) showed at the end of 4 years, a patient had a 95% chance of not having revision surgery. Statistically, there was no association between outcome and cofactors such as scoliosis, spondylolisthesis, number of levels decompressed, discectomy, or smoking. Satisfaction rates for older patients were similar to patients younger than 65 years although physical function scores and severity scores were less.

Aged↗
PubMed2001

Decompression, fusion, and instrumentation surgery for complex lumbar spinal stenosis.

Between 1990 and 1993, 54 consecutive patients were treated with decompression, fusion and instrumentation surgery for complex lumbar spinal stenosis. The mean age of the patients was 60 years. The average followup was 39 months. Clinically, there was one deep wound infection, and three mechanical failures. There were two staged operations. There were three revision surgeries performed for mechanical reasons. Of the 47 patients who completed the questionnaire, 96% of patients were very satisfied or somewhat satisfied with the operation, 98% were satisfied with relief of pain, 94% were satisfied with their ability to walk, 89% were satisfied with their strength, and 94% were satisfied with balance. Survivorship analysis (failure endpoint was revision surgery) revealed that at the end of 4 years, the patient had a 92% chance of not undergoing revision surgery for any reason (mechanical and infectious), and a 94% chance of not undergoing revision surgery for mechanical reasons. Lumbar decompression, fusion, and instrumentation surgery seems to be efficacious in patients with complex lumbar spinal stenosis (associated previous lumbar spine operations with evidence of radiographic instability, radiographic evidence of junctional stenosis after surgery, radiographic evidence of instability, degenerative spondylolisthesis greater than Grade I with instability, if present, and degenerative scoliosis with a curve greater than 20 degrees).

Decompression, Surgical↗
PubMed2001

Domestic cat model for predicting human nucleoside analogue pharmacokinetics in blood and seminal plasma.

To establish whether a feline model can predict nucleoside analogue behavior in human semen, zidovudine (ZDV) and lamivudine (3TC) pharmacokinetic parameters (PKs) were determined in the blood and seminal plasma of healthy cats. Our results show considerable similarity in ZDV and 3TC PKs between cats and humans. As in humans, ZDV and 3TC tend to accumulate in feline seminal plasma. Area under the blood plasma concentration-time curve was predictive of seminal plasma excretion. The felid model offers a unique in vivo experimental alternative for investigating the pharmacokinetics of nucleoside analogues in the male genital tract.

Animals↗
PubMed2001

Structure-function correlation of laminar vascularity in human rectus extraocular muscles.

PURPOSE: Orbital and global layers of rectus extraocular muscles (EOMs) are believed to serve different functions. This study sought anatomic and functional evidence of differing blood flow in the two layers of rectus EOMs. METHODS: Four human orbits ranging in age from 17 months to 93 years were serially sectioned and stained for muscle fibers with Masson's trichrome and for vascular smooth muscle with monoclonal antibody to smooth muscle alpha-actin. Digitally assisted microscopy was used to obtain measurements of luminal cross sections and counts of muscular blood vessels, as well as measurements of muscle fiber number and cross-sectional areas of the two layers. Findings were correlated with first-pass gadodiamide contrast magnetic resonance imaging (MRI) in two living humans to demonstrate relative perfusion of EOMs. RESULTS: In all rectus EOMs, the orbital layer had significantly more vessels per unit area, more vessels per fiber, and more total vascular luminal area, than the global layer (P: < 0.05). Vascularity of EOMs was greatest in the youngest specimen. First-pass contrast MRI was consistent with perfusion of the orbital layer earlier than the global layer of living human rectus EOMs. CONCLUSIONS: Orbital layers of human rectus EOMs have significantly more muscular vessels than the global layers and stain earlier after intravenous bolus injection of paramagnetic MRI contrast. These findings suggest higher and even more rapid blood flow in the orbital layers that may correlate with greater metabolic activity. Greater blood flow is consistent with more sustained mechanical loading of the orbital than the global layer.

Adult↗
PubMed2001

A data compression method for image time series.

Image time series for functional studies frequently vary relatively little from one time point to the next. We describe here a method of lossless file compression that calculates the change in signal intensity as a char (one byte), as opposed to a short or long integer (usually two or four bytes), thus resulting in a compressed file size just over half the size of the original (a 2:1 compression ratio). The calculations and format are exceedingly simple; the compression time is comparable to the time required for a file copy, and is thus transparent to most users. The approach works equally well on any integer-based scanning modality, such as PET, CT, or DSA. Our purpose in this communication is to advocate it as a potential standard, to promote free interchange of scan data.

Algorithms↗
PubMed2001

Syndromic treatment of gonococcal and chlamydial infections in women seeking primary care for the genital discharge syndrome: decision-making.

The syndromic treatment of gonococcal and chlamydial infections in women seeking primary care in clinics where resources are scarce, as recommended by WHO and implemented in many developing countries, necessitates a balance to be struck between overtreatment and undertreatment. The present paper identifies factors that are relevant to the selection of specific strategies for syndromic treatment in the above circumstances. Among them are the general aspects of decision-making and caveats concerning the rational decision-making approach. The positive and negative implications are outlined of providing or withholding treatment following a specific algorithm with a given accuracy to detect infection, i.e. sensitivity, specificity and predictive values. Other decision-making considerations that are identified are related to implementation and include the stability of risk factors with regard to time, space and the implementer, acceptability by stakeholders, and environmental constraints. There is a need to consider empirically developed treatment algorithms as a basis for policy discourse, to be evaluated together with the evidence, alternatives and arguments by the stakeholders.

Algorithms↗
PubMed2000

Breakthrough pneumococcal bacteremia in patients being treated with azithromycin and clarithromycin.

Streptococcus pneumoniae strains have exhibited decreasing susceptibility to penicillins and macrolides during the past several years. We reviewed the medical charts of all patients with pneumococcal bacteremia who were admitted to a university hospital over a period of 1 year, to identify failures of outpatient therapy. Of 41 patients admitted with pneumococcal bacteremia, 4 had previously taken either azithromycin or clarithromycin for 3-5 days. All 4 had pneumococcal strains that exhibited low-level resistance to macrolide antibiotics. Among pneumococci, low-level resistance to macrolides can lead to clinical failure, and resistance to macrolides should be considered during the selection of empiric therapy for patients with presumed pneumococcal infections.

Aged↗
PubMed2000

Patterns of brain activation in people at risk for Alzheimer's disease.

BACKGROUND: The epsilon4 allele of the apolipoprotein E gene (APOE) is the chief known genetic risk factor for Alzheimer's disease, the most common cause of dementia late in life. To determine the relation between brain responses to tasks requiring memory and the genetic risk of Alzheimer's disease, we performed APOE genotyping and functional magnetic resonance imaging (MRI) of the brain in older persons with intact cognition. METHODS: We studied 30 subjects (age, 47 to 82 years) who were neurologically normal, of whom 16 were carriers of the APOE epsilon4 allele and 14 were homozygous for the APOE epsilon3 allele. The mean age and level of education were similar in the two groups. Patterns of brain activation during functional MRI scanning were determined while subjects memorized and recalled unrelated pairs of words and while subjects rested between such periods. Memory was reassessed in 14 subjects two years later. RESULTS: Both the magnitude and the extent of brain activation during memory-activation tasks in regions affected by Alzheimer's disease, including the left hippocampal, parietal, and prefrontal regions, were greater among the carriers of the APOE epsilon4 allele than among the carriers of the APOE epsilon3 allele. During periods of recall, the carriers of the APOE epsilon4 allele had a greater average increase in signal intensity in the hippocampal region (1.03 percent vs. 0.62 percent, P<0.001) and a greater mean (+/-SD) number of activated regions throughout the brain (15.9+/-6.2 vs. 9.4+/-5.5, P=0.005) than did carriers of the APOE epsilon3 allele. Longitudinal assessment after two years indicated that the degree of base-line brain activation correlated with degree of decline in memory. CONCLUSIONS: Patterns of brain activation during tasks requiring memory differ depending on the genetic risk of Alzheimer's disease and may predict a subsequent decline in memory.

Aged↗
PubMed2000

Simultaneous determination of lamivudine and zidovudine concentrations in human seminal plasma using high-performance liquid chromatography and tandem mass spectrometry.

A HPLC-MS-MS method was developed and validated to measure lamivudine and zidovudine simultaneously in small volumes of human seminal plasma. Sample preparation was simple and rapid, requiring 25 microl of sample, the use of isotopically labeled lamivudine and zidovudine as internal standards and ultrafiltration through a molecular mass cut-off membrane. Lamivudine and its internal standard were separated from zidovudine and its internal standard with isocratic HPLC. Detection was carried out using tandem mass spectrometry. This validated method was used to analyze seminal samples obtained from six HIV-positive patients prescribed lamivudine and zidovudine.

Anti-HIV Agents↗
PubMed2000

Features of urethritis in a cohort of male soldiers.

Of 400 cases of urethritis in male soldiers enrolled in a behavioral intervention project, the etiology of 69% was defined at study enrollment, as well as the etiology of 72% of 25 repeated episodes involving 21 men during the first 78 days of active follow-up (5% of the cohort). Chlamydia trachomatis (36%), Neisseria gonorrhoeae (34%), and Ureaplasma urealyticum (19%) were the most common causes of infection identified at enrollment and during subsequent visits (44%, 28%, and 12%, respectively). By univariate analysis, patients with repeated infection ("repeaters") were significantly more likely to report a history of sexually transmitted disease (STD; relative risk [RR], 3) and sex with sex workers (RR, 4) than were nonrepeaters. By multivariate analysis, only STD history was significant (RR, 2.8). Characteristics of repeaters in this cohort suggest that specific patterns may be used to establish screening "profiles" of potential repeaters, by which such individuals might be targeted for aggressive intervention at the time of the initial diagnosis.

Adult↗
PubMed2000

Trends of gonorrhea and chlamydial infection during 1985-1996 among active-duty soldiers at a United States Army installation.

High rates of sexually transmitted diseases (STDs) have been reported in military populations. However, it remains uncertain whether the incidence of STDs is higher among military personnel than in the civilian population. The annual incidence of gonorrhea and chlamydia from 1985 through 1996 at Fort Bragg, North Carolina, was determined by use of a clinic database and demographic information for the entire installation. A direct standardization for age, sex, and race/ethnicity was performed, and the adjusted annual rates among active duty soldiers were compared with rates among men and women in North Carolina and the United States. Results showed that the adjusted incidence of gonorrhea and chlamydia among Fort Bragg soldiers remained higher overall than comparable state and national rates during the period of analyses. The 1996 adjusted chlamydia rates for male and female active duty soldiers were 3-fold to 6-fold higher than rates for males and females in North Carolina and in the United States as a whole. STDs continue to lead to significant morbidity in this representative military population.

Adolescent↗