PubMed Health⌕ Search

Biomedical subjects

J J Johnson

Publications and source records attributed to J J Johnson.

At least 37 records · Page 2Linked to original sources
PubMed1991

Severe hypercarbia resulting from inspiratory valve malfunction in two anesthetized horses.

Severe hypercarbia was documented by arterial blood gas analysis in 2 adult horses anesthetized for exploratory laparotomy. Both horses appeared to be adequately anesthetized, but continued to breathe against the ventilator. In both cases, the inspiratory valve on the anesthesia machine was found to be stuck open, permitting expired CO2 to return to the inspiratory limb of the anesthetic circuit and to be inhaled with the next breath. Correction of the malfunctioning valve alleviated the hypercarbia. Problems with the flow valves of the anesthesia machine should be suspected when anesthetized horses breathe against the ventilator and develop severe hypercarbia.

Anesthesia↗
PubMed1991

Lung ischemia-reperfusion injury in awake sheep: protection with verapamil.

We caused unilateral lung ischemia-reperfusion injury in awake sheep by simultaneously occluding the left pulmonary artery and left main stem bronchus for 12 h. The occluded left lung was inflated with nitrogen. Reperfusion resulted in an elevation of lung lymph flow from 1.3 to 5.0 ml/15 min and an increase in lymph-to-plsma protein concentration ratios. Reperfusion, but not ischemia alone, caused an increase in wet-to-dry weight ratios in both the reperfused left lung and the contralateral right lung. Granulocytes increased in both lungs during the ischemic period and after reperfusion, and hypoxemia developed after reperfusion. The calcium channel antagonist, verapamil, given just before reperfusion, caused a marked attenuation in the reperfusion-induced changes in the lung lymph variables and wet-to-dry weight ratio. However, verapamil did not affect the hypoxemia or granulocyte sequestration seen after reperfusion. We conclude that reperfusion of ischemic sheep lung results in increased microvascular permeability that can be partially prevented by verapamil.

Animals↗
PubMed1990

The Caenorhabditis elegans rol-6 gene, which interacts with the sqt-1 collagen gene to determine organismal morphology, encodes a collagen.

The rol-6 gene is one of the more than 40 loci in Caenorhabditis elegans that primarily affect organismal morphology. Certain mutations in the rol-6 gene produce animals that have the right roller phenotype, i.e., they are twisted into a right-handed helix. The rol-6 gene interacts with another gene that affects morphology, sqt-1; a left roller allele of sqt-1 acts as a dominant suppressor of a right roller allele of rol-6. The sqt-1 gene has previously been shown to encode a collagen. We isolated and sequenced the rol-6 gene and found that it also encodes a collagen. The rol-6 gene was identified by physical mapping of overlapping chromosomal deficiencies that cover the gene and by identification of an allele-specific restriction site alteration. The amino acid sequence of the collagen encoded by rol-6 is more similar to that of the sqt-1 collagen than to any of the other ten C. elegans cuticle collagen sequences compared. The locations of cysteine residues flanking the Gly-X-Y repeat regions of rol-6 and sqt-1 are identical, but differ from those in the other collagens. The sequence similarities between rol-6 and sqt-1 indicate that they represent a new collagen subfamily in C. elegans. These findings suggest that these two collagens physically interact, possibly explaining the genetic interaction seen between the rol-6 and sqt-1 genes.

Amino Acid Sequence↗
PubMed1989

Female clerical workers' perceived work and nonwork stress and dissatisfaction as predictors of psychological distress.

The present investigation explored the predictability of psychological distress from perceived work and nonwork stress and dissatisfaction for a sample of 108 female clerical workers. A stepwise multiple regression was performed on the data, and it was found that nonwork variables contributed more to perceived psychological distress than did work variables. Implications of this research as related to gender and organizational concerns are discussed.

Adaptation, Psychological↗
PubMed1989

Skin color and ear oximetry.

Measurements of arterial blood oxygen saturation from two ear oximeters were compared with 655 simultaneously drawn arterial blood samples in 187 patients grouped by skin color quantified by the Munsell color system. Technical problems including warning lights and messages with the two ear oximeters were recorded. There were significantly more technical problems in patients with the darkest skin color associated with inability to obtain a reading or warning message indicating poor tissue penetration of the signal (18 and 15 percent vs 1 percent). When readings could be obtained, the ear oximetry readings were found to be slightly less accurate in the darker patient groups. These findings suggest that dark skin color may affect the performance and accuracy of ear oximeters, including the newer type of pulse oximeters.

Blood Gas Monitoring, Transcutaneous↗
PubMed1989

Jaccoud's-type arthropathy: an association with malignancy.

We describe a patient who developed Jaccoud's type arthropathy as an initial manifestation of small cell anaplastic carcinoma of the lung. This is the first time this arthropathy has been reported as a musculoskeletal manifestation of malignancy.

Aged↗
PubMed1988

The sqt-1 gene of C. elegans encodes a collagen critical for organismal morphogenesis.

Different mutations in the sqt-1 gene of C. elegans can lengthen, shorten, or helically twist the entire animal. We have cloned the sqt-1 gene and have shown that it encodes a collagen. sqt-1 was localized to a 35 kb region of DNA by physical mapping of chromosomal deficiencies. A transposon (Tc1)-induced mutation of sqt-1 was generated and utilized to identify the sqt-1 gene within this 35 kb region. Sequence analysis of the sqt-1 gene shows that it encodes a 32 kd collagen polypeptide that is similar in size and structure to other members of the C. elegans collagen family. The Tc1 insertion mutant has no detectable sqt-1 transcripts, yet it is morphologically normal, indicating that the null phenotype of sqt-1 is wild type. These results demonstrate that collagen mutations can have dramatic effects on organismal morphology.

Alleles↗
PubMed1988

Coexistence of Paget's disease and dermatomyositis.

The occurrence of Paget's disease and dermatomyositis in a single patient has not been previously reported. We present 2 patients with this combination of disorders and consider why these diseases might coexist.

Dermatomyositis↗
PubMed1987

Toxicity of methotrexate in rheumatoid arthritis.

Seventy-two patients with rheumatoid arthritis had been treated with pulse weekly oral methotrexate with a mean followup of one year. Minor side effects (oral ulcers, transient elevation of liver enzymes, nausea, vomiting) were present in 46 patients (63.8%), whereas major side effects (severe infection, cytopenia, respiratory failure, seizures, gastrointestinal bleeding) were present in 7 (9.7%), 2 of whom died. Patients with major side effects had shorter disease duration and increased frequency of extraarticular manifestations as compared to those with no side effects. No association between a particular clinical or genetic variable and occurrence of side effects to methotrexate was found.

Administration, Oral↗
PubMed1986

Spontaneous enophthalmos from chronic maxillary sinusitis.

Spontaneous enophthalmos has been reported to occur after demineralization of the orbital floor from chronic maxillary sinusitis. We report a 24-year-old female who developed spontaneous enophthalmos without demineralization of the orbital floor. A contracture from the maxillary sinus apparently pulled the orbital floor downward. Release of the fibrous tissue through a combined orbital and sinus approach produced satisfactory correction of the enophthalmos without the use of alloplastic implants. This case suggests that fibrotic contraction in the maxillary sinus pulling the floor of the orbit downward can produce spontaneous enophthalmos without boney destruction.

Adult↗
PubMed1977

A validity study of the Neural Efficiency Analyzer in relation to selected measures of intelligence.

This study attempted to determine the validity of the Ertl Neural Efficiency Analyzer as a measure of intellectual ability by using NEA-Alpha and Neural Efficiency scores to predict collage grade point average (GPA) both alone and in combination with paper-and-pencil measures of intelligence for 22 male and 64 female college students. Results indicate that NEA-Alpha scores can predict GPA with moderate sucess and also that NEA-Alpha scores account for variability in grade point average not associated with paper-and-pencil tests.

Adult↗