A model for the delivery of care for HIV-positive clients.
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Adolescent↗
Biomedical subjects
M Cohen
Publications and source records attributed to M Cohen.
Case report: empyema with hydropneumothorax and bacteremia caused by Clostridium sporogenes.
Clostridia species are rare causes of pleuropulmonary infections. This report describes an immunocompromised patient who had a renal transplant, had multiple risk factors for anaerobic pleuropulmonary infection, and developed an acute empyema with hydropneumothorax that was associated with Clostridium sporogenes bacteremia. Therapy included antibiotics and surgical drainage of the empyema. Species identification of clostridia can usually be limited to whether the species is perfringens or nonperfringens because the majority of clinically significant clostridial infections are caused by Clostridium perfringens. Increased cost and consumption of time limits the usefulness of species identification of nonperfringens species. However, the identification of clostridia species that are known to be associated with specific underlying diseases or known to have variable and unpredictable antibiotic susceptibilities may affect patient management. The role of the laboratory in identifying such anaerobic isolates is discussed.
Bacteremia↗
Simultaneous distraction osteogenesis and microsurgical reconstruction for facial asymmetry.
Restoring facial balance in patients with severe facial asymmetry is a challenging problem for the craniofacial team. Attention to bony reconstruction as well as soft-tissue contouring is required for patients with moderate to severe deformities. Traditionally, facial skeletal reconstruction was performed with osteotomies and bone grafting. More recently, distraction osteogenesis has proven to be successful in achieving bone lengthening. For select cases, distraction osteogenesis has lessened the need for major skeletal procedures and has allowed earlier surgical intervention. The reconstruction of the soft tissues in facial asymmetry has generally been performed as a second-stage procedure after skeletal reconstruction. The disadvantage of these traditional approaches is that it requires two separate major operative procedures, with the accompanying increased morbidity, hospital stay, and cost. We present a patient with hemifacial microsomia and a grade III mandibular deformity, in whom both the hard- and soft-tissue deficiencies were corrected in one surgical procedure with mandibular distraction osteogenesis and soft-tissue augmentation with a vascularized parascapular osteocutaneous flap. The technique and results at 1-year follow-up are presented.
Adolescent↗
Positive end-expiratory pressure-induced hemodynamic changes are reflected in the arterial pressure waveform.
OBJECTIVE: To examine whether the hemodynamic changes due to mechanical ventilation with positive end-expiratory pressure (PEEP) can be assessed by the respiratory-induced variations in the arterial pressure waveform during normovolemia and experimental acute ventricular failure. DESIGN: Prospective, controlled experimental study. SETTING: Institutional experimental laboratory. SUBJECTS: Adult mongrel dogs. INTERVENTIONS: Experimental acute ventricular failure was induced by the infusion of pentobarbital (a cardiodepressant) and methoxamine (a vasoconstrictor), combined with volume loading. Both the control and acute ventricular failure groups were subjected to ventilation with incremental levels of PEEP up to 20 cm H2O. MEASUREMENTS AND MAIN RESULTS: Cardiac function was evaluated by cardiac output and left and right ventricular change in pressure over time (dP/dt) measurements. Arterial pressure waveform analysis was performed by measuring the systolic pressure variation, which is the difference between the maximal and minimal systolic blood pressure values during one mechanical breath. The components of the systolic pressure variation, namely, dUp and dDown, which are the increase and decrease in the systolic pressure during the mechanical breath relative to the systolic pressure during apnea, were also measured at each PEEP level. PEEP caused significant reduction of cardiac output in normovolemic dogs, and was associated with significant increases in systolic pressure variation and dDown. Acute ventricular failure decreased the variations in the systolic pressure and caused the dDown component to disappear. The application of PEEP did not affect cardiac output in dogs with acute ventricular failure, nor did it change systolic pressure variation and the dDown. CONCLUSIONS: Analysis of arterial pressure waveforms during mechanical ventilation reflected the decrease in cardiac output in dogs with normal cardiac function subjected to incremental PEEP. In dogs with acute ventricular failure in which PEEP did not affect cardiac output, the systolic pressure variation was similarly unaffected by PEEP. In the absence of cardiac output measurement during mechanical ventilation with PEEP, the analysis of the respiratory variations in the arterial pressure waveform may be useful in assessing changes in cardiac output.
Animals↗
First-pass evaluation of myocardial output during dipyridamole stress using turbo-FLASH magnetic resonance imaging.
RATIONALE AND OBJECTIVES: This study evaluated the value of dynamically enhanced fast low-angle shot (FLASH) magnetic resonance (MR) imaging in measuring cardiac output with and without dipyridamole pharmacological stress. METHODS: Ten subjects underwent rest and stress MR imaging. Rest images were acquired using electrocardiogram gated MR (turbo-FLASH: repetition time = 6 mseconds; echo time = 12 mseconds; flip angle = 12 degrees, inversion time = 100) 10 to 45 seconds after intravenous bolus of 0.04 mmol/kg gadolinium (Gd)-DTPA using a Siemens 1.0-tesla Magnetom SP. Stress was induced within the MR imaging scanner with 0.56 mg/kg dipyridamole over 4 minutes with stress MR images obtained after a second bolus of Gd-DTPA in exactly the same position and time intervals. Cardiac output was calculated with a least squares error analysis before and after dipyridamole stress for the left and right ventricles in all 10 patients, and comparison was made with cardiac output by Fick dilution technique during cardiac catheterization in seven patients. RESULTS: This MR analysis methodology shows reasonable correlation (r = 0.953) between left ventricular and right ventricular cardiac output with no effect on cardiac output during immediate dipyridamole stress. Fick dilution studies demonstrated a correlation of 0.96. CONCLUSIONS: Turbo-FLASH MR can demonstrate time-activity curves and cardiac output calculations consistent with theoretical predictions.
Aged↗
Speech characteristics associated with the Furlow palatoplasty as compared with other surgical techniques.
Reported here are the results of a retrospective study of the speech outcome for 63 cleft subjects who had Furlow repairs compared with 20 subjects who had other procedures. The two groups of children were similar in cleft type, sex, and race. The same two surgeons repaired the palates in both groups, and the same two speech pathologists with high reliability examined the children at least 5 years postoperatively using the Pittsburgh Weighted Values for Speech Symptoms Associated with VPI (velopharyngeal incompetence). Subjects who had had Furlow repairs were superior on measures of hypernasality, articulation, and total speech scores; and fewer pharyngeal flaps were required by Furlow subjects. These findings suggest the need for randomized, double-blind investigations comparing outcome of the Furlow procedure with the intravelar veloplasty, the V-Y pushback, and other specified procedures.
Cleft Palate↗
Dielectronic recombination and excitation autoionization rate coefficients for potassiumlike Mo23+ to fluorinelike Mo33+
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Journal Article↗
Single-mode selection and axial mode control in a free-electron maser oscillator using a prebunched electron beam.
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Journal Article↗
Elevated levels of the endogenous retrovirus ERV3 in human sebaceous glands.
ERV3 (HERV-R) is a complete human endogenous retrovirus located on the long arm of chromosome 7. Long terminal repeat-envelope (env) gene spliced mRNAs of 9 and 3.5 kb are widely expressed in human tissues and cells, but gag-pol mRNAs have not been found. Furthermore, the env gp70 gene contains an open reading frame throughout its length. The highest expression of ERV3 mRNA detected so far is in placenta and the lowest in choriocarcinoma cell lines. We have previously shown that the human monoblastic cell line U-937 and some normal and neoplastic tissues also express high levels of ERV3 env message by Northern blot analysis; however, this method does not distinguish between mRNA expression in different cell types in tissues. In this report, we have studied the ERV3 mRNA expression in specific cell types of human skin by in situ hybridization. We found high levels expression of ERV3 env mRNA in human sebaceous glands in normal skin and dermoid cysts of the ovary. In all glands, the expression is maximal in the periphery of the lobule and ceases towards the center in the region of characteristic holocrine secretion. Since it is known that the regulation of sebaceous glands is primarily via steroid hormones, particularly androgens, it is possible that expression of ERV3 is hormone dependent.
Adolescent↗
Two brothers with multiple congenital anomalies and mental retardation due to disomy (X)(q12-->q13.3) inherited from the mother.
We present the phenotypic, cytogenetic and molecular findings in two dysmorphic and mentally retarded brothers with disomy Xq12-->q13.3. The mother and the grandmother carry the same rearrangement of the X chromosome, which was interpreted as an inverted insertion of the segment (X)(q12-->q13.3) into Xq21.2. The X-inactivation-specific-transcript (XIST) is expressed in the probands mother but is absent in her son, confirming the hypothesis that X inactivation is realized only if two X inactivation centers reside on different X-chromosomes (trans-configuration). In the phenotypically normal mother the aberrant X chromosome was late replicating in all cells, indicating functional monosomy of the constitutional segment trisomy. The phenotype of the brothers is considered to be the consequence of a functional disomy Xq12-->q13.3. The trait combination observed in the brothers was compared with the spectrum of clinical and anthropological traits for proximal Xq disomy in males, elaborated by phenotype analyses of the available literature cases.
Abnormalities, Multiple↗
Sentinel lesions of primary CNS lymphoma.
Some patients ultimately diagnosed with primary CNS lymphoma (PCNSL) have transient symptomatic contrast enhancing lesions. These "sentinel lesions" of PCNSL recede spontaneously or with corticosteroid treatment and present an important diagnostic dilemma because they show variable, but non-diagnostic histopathological features. Four previously healthy, immunocompetent patients aged 49 to 58 years had contrast enhancing intraparenchymal brain lesions. Before biopsy, three of the four were treated with corticosteroids. Initial biopsies showed demyelination with axonal sparing in two, non-specific inflammation in one, and normal brain in one. Infiltrating lymphocytes predominantly expressed T cell markers with rare B cells. All four patients recovered within two to four weeks after the initial biopsy and imaging studies showed resolution of the lesions. The CSF was normal in three of the four patients tested; oligoclonal bands were absent in both of the two tested. After seven to 11 months, each patient developed new symptomatic lesions in a different region of the brain, biopsy of which showed a B cell PCNSL. The mechanism of spontaneous involution of sentinel lesions is not understood, but may represent host immunity against the tumour. Sentinel lesions of PCNSL should be considered in patients with contrast enhancing focal parenchymal lesions that show non-specific or demyelinative histopathological changes. Close clinical and radiographic follow up is essential if PCNSL is to be diagnosed early in such patients.
Adrenal Cortex Hormones↗
Pontine lesions in idiopathic narcolepsy.
Three patients had longstanding (37 to 50 years), highly disabling narcolepsy, poorly controlled by treatment. The clinical histories were typical, consisting of sleepiness, cataplexy, sleep paralysis, hypnagogic hallucinations, disturbed nocturnal sleep, and HLA-DR2 tissue typing. Polygraphic findings confirmed the diagnosis. Neurologic examination, spinal fluid, and evoked potentials were normal. On MRI scanning, all three patients showed overlapping bilateral and symmetric brainstem T2 hyperintensities circumscribed to the ventrolateral aspect of the midrostral pons. The nature of the lesions remains uncertain but their location corresponded to the pontine oral reticular formation, where the neuronal network generating REM sleep is located. This is the first report of MR signal abnormalities in patients with idiopathic narcolepsy and suggests a causal relationship between the disease and the central pontine lesions.
Aged↗
Early pathologic and biochemical changes in Creutzfeldt-Jakob disease: study of brain biopsies.
We examined brain biopsy tissue from five patients with a neurologic syndrome consistent with Creutzfeldt-Jakob disease using Western blot analysis and immunohistochemistry for the detection of protease-resistant prion protein, in addition to histopathologic examination. Our results indicate that the formation of protease-resistant prion protein is an early event in disease pathogenesis and Western blot analysis can detect protease-resistant prion protein in the absence of structural lesions using a small amount of brain biopsy tissue.
Adult↗
Noninvasive positive pressure ventilation in status asthmaticus.
OBJECTIVE: In asthmatic patients with acute respiratory failure (ARF), placing an endotracheal tube is associated with a high rate of complications and results in increased airway resistance. In acute asthma, mask-continuous positive airway pressure (CPAP) decreases airway resistance and the work of breathing (WOB), but does not improve gas exchange. In COPD with ARF, adding intermittent positive pressure ventilation to mask-CPAP results in an additional improvement in WOB and is highly effective in correcting gas exchange abnormalities. In our medical ICU, noninvasive positive pressure ventilation (NPPV) is used as first-line interventional therapy in eligible patients with hypercapnic ARF. We report our experience with NPPV in 17 episodes of asthma and ARF over a 3-year period. METHODS: A face mask was secured with head straps, avoiding a tight fit, and connected to a ventilator (PB-7200). Initial ventilatory settings included CPAP at 4 +/- 2 cm H2O to offset intrinsic positive end-expiratory pressure and pressure support ventilation (PSV) at 14 +/- 5 cm H2O aiming at a respiratory rate less than 25 breaths/min and an exhaled tidal volume of 7 mL/kg or more. PSV was then adjusted following arterial blood gas results. RESULTS: Mean age was 35.4 +/- 11.3 years; 10 patients were female. The mean (+/- SE) for different physiologic values are reported at initiation, less than 2 h, 2 to 6 h, and 12 to 24 h into NPPV. pH was 7.25 +/- 0.01, 7.32 +/- 0.02 (p = 0.0012), 7.36 +/- 0.02 (p < 0.0001), and 7.38 +/- 0.02; PaCO2 was 65 +/- 2, 52 +/- 3(p = 0.002), 45 +/- 3(p < 0.0001), and 45 +/- 4; PaO2 fraction of inspired oxygen was 315 +/- 41, 403 +/- 47, 367 +/- 47, and 472 +/- 67 (p = 0.06); and respiratory rate was: 29.1 +/- 1, 22 +/- 1 (p < 0.0001), 20 +/- 1, and 17 +/- 1. NPPV was well tolerated, and only two patients required sedation. Initial delivered minute ventilation was 16 +/- 4 L/min. The mean (+/- SD) peak inspiratory pressure to ventilate in the NPPV-treated patients was 18 +/- 5 cm H2O and always less than 25 cm H2O. There was no complication or problem with expectorating of secretions. Oral intake (liquid diet) was preserved. Two patients required intubation (35 min and 89 h into NPPV) for worsening PaCO2. Duration of NPPV was 16 +/- 21 h. All patients survived. Length of hospital stay was 5 +/- 4 days. CONCLUSIONS: In asthmatic patients with ARF, NPPV via a face mask appears highly effective in correcting gas exchange abnormalities using a low inspiratory pressure (< 25 cm H2O). A randomized study is in progress to assess fully the role of NPPV in status asthmaticus.
Adult↗
Teaching model for closure of oronasal fistula and bone grafting of the maxilla.
Secondary bone grafting of the maxilla and closure of the residual oronasal fistula at the stage of transitional dentition has become a well-accepted treatment modality. This procedure, in conjunction with orthodontic treatment, has been incorporated into the management protocol of many cleft teams around the world in an effort to further improve functional and esthetic habilitation of patients with unilateral or bilateral clefts of the lip, alveolus, and palate.
Bone Transplantation↗
Intraoral-appliance modification to retract the premaxilla in patients with bilateral cleft lip.
Management of the protrusive premaxilla in patients with bilateral cleft lip is challenging for the reconstructive team. Several intra- and extraoral orthopedic techniques to reposition the protrusive premaxilla prior to bilateral cleft lip repair have been presented in the literature. A modification to a previously described tissue-borne palatal plate with a latex strap is presented. In the modified plate, the latex strap is replaced by an orthodontic elastomeric chain, and the chain over the prolabium is covered with soft denture liner. This appliance is effective in retracting the premaxilla, noninvasive, easy to construct and adjust, economic, well tolerated by the patient, and accepted by the parents.
Cleft Lip↗
Dips on Békésy or audioscan fail to identify carriers of autosomal recessive non-syndromic hearing loss.
Békésy and audioscan sweep audiometry tests were carried out in 24 presumed obligate carriers of autosomal recessive non-syndromic hearing loss and 30 sex and age appropriate controls, with a view to defining the most expedient criteria for dips on either test in respect of possible carrier detection. On Békésy, dips with a minimum depth of 22.5 dB generated the greatest difference between carriers and non-carriers, while on audioscan, the criterion of a minimum dip depth of 15 dB provided the best discriminant. Using these criteria, the prevalence of dips was also evaluated in 8 unaffected siblings and 24 age appropriate control subjects. The findings both in the adult and the paediatric groups do not support the hypothesis that the presence of dips, either on Békésy or audioscan, is linked to the carrier state in ARNSHL.
Acoustic Impedance Tests↗
Auditory deficits and hearing loss associated with focal brainstem haemorrhage.
Four cases of central pontine haemorrhage are described in which auditory dysfunction was documented. Two cases had a hearing loss, in one of which there was recovery of the low frequencies. This case provides support for the tonotopic organization of the auditory pathways in the caudal pontine area, with the lowest frequencies being encoded medially. In all cases, there were abnormalities of the auditory brainstem responses, wave V being consistently involved, while wave III was abnormal in only one patient. In three cases, the masking level differences and crossed acoustic reflex thresholds were abnormal. The ipsilateral reflex thresholds were normal at least on one side in all cases. In the patient with the most significant hearing loss, loudness recruitment, assessed both psychophysically and with the acoustic reflex thresholds, was evident. These data are interpreted in terms of there being damage to the medial superior olivary nuclei and trapezoid body involving both afferent and efferent fibres.
Adult↗