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J R Cohn

Publications and source records attributed to J R Cohn.

At least 19 recordsLinked to original sources
PubMed1999

False positive perfusion lung scintiscans in tetraplegic patients: a case series.

An accurate diagnosis of pulmonary embolism is essential to prevent excessive morbidity and mortality from either inappropriate therapy or failure to institute anticoagulation. The diagnosis of pulmonary embolism in tetraplegic spinal cord injury patients is complicated by frequent inability to perform the ventilation portion of the ventilation-perfusion scintiscan (V/Q scan) and by controversy regarding classification of defects on perfusion-only scans, as well as by coexisting pulmonary disease, systemic illness, related injuries, and the tendency for tetraplegic patients to have unexplained fever. This report describes three tetraplegic ventilator-dependent patients with hypoxic respiratory failure and normal chest radiographs who had large defects on perfusion-only lung scans. Ventilation scintiscans were not performed because the patients were ventilator-dependent with tracheostomies. Pulmonary angiography findings were normal in all patients, and all three responded to aggressive pulmonary toilet. Even large defects on perfusion-only scans despite normal chest radiographs should not be used to establish a diagnosis of pulmonary embolism in tetraplegic patients, and further diagnostic imaging is warranted.

Adult↗
PubMed1996

Respiratory and glottal efficiency measures in normal classically trained singers.

Respiratory and glottal efficiency measures were collected from a pool of 40 classically trained singers with normal larynges. All singers had > or = 3 years of formal classical voice training and were active professional solo classical singers. Mean flow rates were obtained from all subjects to assess glottal efficiency. Additionally, maximum phonation times and phonation quotients were obtained from a subset of the singers. Pulmonary function test data on forced expiratory volume, forced vital capacity, and forced expiratory flow were obtained for all subjects. Results were compared with published normal values, not specifically derived from trained singers, used commonly in voice laboratories. Differences were found, suggesting the need for separate normative data to be used for evaluation of the vocal athlete.

Adult↗
PubMed1996

Expression of the early nodulin, ENOD40, in soybean roots in response to various lipo-chitin signal molecules.

The lipo-chitin (LCO) nodulation signal (nod signal) purified from Bradyrhizobium japonicum induced nodule primordia on soybean (i.e. Glycine soja) roots. These primordia were characterized by a bifurcated vascular connection, cortical cell division, and the accumulation of mRNA of the early nodulin gene, ENOD40. A chemically synthesized LCO identical in structure to the Nod signal purified from B. japonicum cultures showed the same activity when inoculated on to soybean roots. Surprisingly, synthetic LCO or chitin pentamer, inactive in inducing root hair curling (HAD) or cortical cell division (NOI) in G. soja, induced the transient accumulation of ENOD40 mRNA. In roots inoculated with such LCO, ENOD40 mRNA was abundant at 40 h after inoculation but decreased to the background levels 6 days after inoculation. In contrast, nod signals active in inducing HAD and NOI induced high levels of ENOD40 accumulation at 40 h and 6 days after inoculation. In situ hybridization analysis showed that ENOD40 mRNA accumulated in the pericycle of the vascular bundle at 24 h after root inoculation with nod signal. At 6 days post-inoculation with nod signal, ENOD40 expression was seen in dividing subepidermal cortical cells. These results provide morphological and molecular evidence that nodule induction in soybean in response to purified or synthetic nod signal is similar, if not identical, to nodule formation induced by bacterial inoculation. Surprisingly, ENOD40 mRNA accumulation occurs in response to non-specific chitin signals. This suggests that, in the case of ENOD40, nodulation specificity is not determined at the level of initial gene expression.

Base Sequence↗
PubMed1996

Cooperative action of lipo-chitin nodulation signals on the induction of the early nodulin, ENOD2, in soybean roots.

Various lipo-chitin molecules were tested for their ability to induce the expression of the early nodulin, ENOD2, in Glycine soja roots. When inoculated separately onto G. soja roots, LCO-V (C18:1 delta 11,Mefuc), LCO-V (C18:1 delta 9,Mefuc), LCO-V (C16:0,Mefuc), and LCO-IV (C16:0) were unable to induce ENOD2 expression, even though these compounds had previously been shown to induce root hair curling, the formation of nodule-like primordia, and induction of the early nodulin, ENOD40. ENOD2 expression, however, was induced when any two of these molecules were inoculated in combination. Thus, the lipo-chitin nodulation signals appear to act cooperatively to induce ENOD2 expression. B. japonicum strains USDA110 and USDA135 and B. elkanii strain USDA61, all symbionts of soybean, were found to produce at least two distinct nod signals ([i.e., NodBj-V[C18:1,Mefuc] and NodBj-V[C16:0,Mefuc]). These two compounds were mixed in various ratios and tested for their ability to induce ENOD2 expression. The results indicate that the former compound must be present in equivalent or excess amount in order to obtain maximum ENOD2 expression. Additional nonspecific LCOs (e.g., LCO-IV[C16:2 delta 2,9; SO3]), incapable of inducing root hair curling or cortical cell division, were tested in combination with the four active LCOs listed above. It was found that any combination of one active LCO with a nonspecific LCO was sufficient to induce ENOD2 mRNA expression. The ENOD2 mRNA expression pattern detected by in situ hybridization closely resembled that found in bacterial-induced nodules with expression detected in cortical cells between primary and secondary meristems and around the vascular strands. These data demonstrate that the cooperative action of at least two LCO nodulation signals leads to a greater progression of nodule ontogeny as demonstrated by the expression of ENOD2, a marker gene for the differentiation of nodule parenchyma.

Carbohydrate Sequence↗
PubMed1995

Vocal disorders and the professional voice user: the allergist's role.

BACKGROUND: As the modulating and power source for the voice, the upper and lower respiratory tracts play a key role in management of voice production. Allergic respiratory disease can impair vocalization, which can be a particular problem in the professional voice user. OBJECTIVE: The goal of this review is to facilitate the evaluation and management of professional voice users who have allergic respiratory problems contributing to their vocal dysfunction. This article discusses the anatomy and physiology of voice production, laryngeal pathology, and special diagnostic and therapeutic considerations relative to the allergist's role in treatment of these patients. METHODS: Mechanisms of voice production are reviewed, as well as common laryngeal pathology effecting voice production. Allergic respiratory diseases are summarized, with particular attention to those aspects of management that are altered in professional voice users. RESULTS: Professional voice users require modification in their management to optimize vocal function and minimize abnormalities of the vocal tract. This includes avoidance of medications that produce drying of the airway, as well as avoidance of inhaled corticosteroids. Subtle changes in respiratory function, which may be of no consequence to other individuals, may adversely affect performance ability, and need aggressive management. Allergen immunotherapy, because of its lack of adverse effects on the vocal apparatus, is particularly well suited for treatment of professional voice users. CONCLUSIONS: Allergists have an important role to play in management of the professional voice user. With careful attention to the unique requirements of these highly trained individuals, the allergist can enhance their performance ability while minimizing side effects from treatment.

Humans↗
PubMed1995

The value of ultrasound-guided fiberoptic bronchoscopy.

Flexible fiberoptic bronchoscopy is the procedure of choice for the diagnosis of endobronchial neoplasm. Because of technical limitations of fiberoptic bronchoscopy, the use of ultrasound assistance was initiated and evaluated. This article reviews the technique, study design, and clinical results of ultrasound-assisted fiberoptic bronchoscopy.

Adult↗
PubMed1994

US-assisted bronchoscopy with use of miniature transducer-containing catheters.

PURPOSE: To demonstrate the value of ultrasound (US) guidance during flexible bronchoscopic procedures in a series of patients with known or suspected pulmonary neoplasms. MATERIALS AND METHODS: US-guided bronchoscopy was carried out as an adjunct to conventional bronchoscopy for the diagnosis of mediastinal, hilar, or parenchymal neoplasms in 25 patients with masses previously detected with chest radiography or computed tomography. Miniature transducer-containing catheters were inserted through the biopsy port of the flexible bronchoscope, and cross-sectional real-time US scans of tumors, lymph nodes, and blood vessels were obtained. RESULTS: Among six cases of peripheral masses and 19 cases of central masses, additional information was provided in 18 cases (72%). This information was used to choose the optimal site for transmural biopsy. CONCLUSION: These preliminary results suggest that this US procedure may become an important diagnostic tool during bronchoscopy, due to the ability to identify structures beyond the lumen of the tracheobronchial tree.

Adult↗
PubMed1993

Determinants of patient compliance with allergen immunotherapy.

BACKGROUND: Allergen immunotherapy (AIM) has been demonstrated to be safe and effective in the treatment of allergic respiratory disease. Although it requires considerable patient commitment, little attention has been paid to the factors that contribute to patient compliance. METHODS: Patients in a practice based at an urban university hospital, who discontinued AIM, were contacted to determine their reasons for stopping treatment. Results were correlated with demographic and disease data obtained from the patient charts. RESULTS: Review of practice records identified 217 patients on AIM. One hundred forty-eight had allergic rhinitis, (R), 66 had allergic rhinitis and asthma (RA), and 3 had allergic asthma without evidence of rhinitis (A). Seventy-four (50%) of the patients in the R group, 32 (48%) of the patients in the RA group, and three (100%) of those in the A group discontinued treatment. The groups differed in that 55% of the patients in the R group discontinued treatment because of inconvenience, compared with only 22% of the patients in the RA group (p < 0.01). By contrast, 25% of the patients in the RA group stopped because they thought that they were "better" with medication, compared with none of the patients in the R group (p < 0.001). All of the patients in the RA group who stopped because they were better completed at least the first four-vial treatment series. CONCLUSIONS: Inconvenience is the major contributing factor in noncompliance with AIM. Regulations designed to protect patients from adverse reactions should balance the potential risk of reactions against the benefits of treatment and the effect of more stringent guidelines on patient compliance.

Adult↗
PubMed1993

Boa constrictor.

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Adult↗
PubMed1992

The role of allergen immunotherapy in the respiratory complications of quadriplegia.

Patients with traumatic quadriplegia have frequent respiratory complications. These complications may be exacerbated by the presence of common and previously well-tolerated allergic disease. Quadriplegic patients are limited in their ability to cope with upper and lower respiratory allergies by a reduced vital capacity and impairment of maneuvers needed to keep the upper and lower respiratory tracts clear. This report describes two patients with traumatic quadriplegia who were treated with allergen immunotherapy. After immunotherapy, both patients had negligible long-term postinjury respiratory complications and an improved quality of life. Allergen immunotherapy should be considered early in the management of allergic patients with traumatic quadriplegia.

Adult↗
PubMed1991

Who's to blame?

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Humans↗
PubMed1989

Flow cytometric evaluation of bronchoscopic washings and lavage fluid for DNA aneuploidy as an adjunct in the diagnosis of lung cancer and tumors metastatic to the lung.

The presence of DNA aneuploidy (deviation from an exact multiple of the diploid amount of DNA) has been used to aid in the diagnoses of several malignancies. We undertook this study to determine if the addition of flow cytometric analysis (FCA) of bronchial washings and lavage specimens for the presence of DNA aneuploidy would increase the yield from bronchoscopy in the diagnosis of lung cancer and other tumors metastatic to the lung. Fifty-nine patients with a variety of both benign (33) and malignant (26) pulmonary disorders had specimens divided and submitted for both FCA and routine cytologic examination. The presence of an "obviously visible" second, aneuploid peak on the DNA histograms proved to be highly specific for the presence of malignancy, but lacked sensitivity. It was concluded that FCA is a promising technique for increasing the diagnostic yield from bronchoscopy at no increased risk to the patient. However, further studies are needed prior to its routine clinical application.

Aneuploidy↗
PubMed1989

Persistent severe asthma in an adult from transient dog exposure: a brief communication.

While atopy is commonly found without signs of asthma, it has been proposed that in some settings, allergen exposure itself can lead to the development of the asthmatic diathesis. To date, this theory has been primarily supported by cases of occupational asthma, where prolonged symptoms have persisted following termination of exposure to the suspect allergen. This model is complicated by associated medicolegal implications, as well as by the generally long-term nature of the exposure, raising questions about the concurrent natural history of a given patient's illness. We report a case of non-occupational dog dander-induced asthma. Exposure was on an intermittent basis over a 15-month period, with the patient exhibiting a classic late phase response. Following discontinuation of exposure to dog dander, he continued to have symptoms, considerably in excess of his findings prior to dog dander exposure.

Adult↗