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Biomedical subjects

R L Green

Publications and source records attributed to R L Green.

At least 55 records · Page 3Linked to original sources

Intravitreal biocompatibility of mussel adhesive protein. A preliminary study.

Mussel adhesive protein (MAP) is a new tissue adhesive derived from the sea mussel Mytilus edulis. Rabbit eyes were injected intravitreally with 1 mg of MAP or balanced salt solution in order to determine the intraocular effects of this new biologic tissue adhesive. Two concentrations of MAP were used: one was undiluted and the other was diluted to a concentration of 1:10. A marked cellular inflammatory response, compared with the control eyes, was seen clinically in the vitreous cavity of animals in which MAP was used undiluted. This response persisted for up to two weeks and was suggestive of inflammatory response to a foreign protein. When MAP was used at a dilution of 1:10, a mild transient cellular reaction was observed in the vitreous; this cleared after seven days. There was no increase in intraocular pressure, and none of the eyes developed cataract or optic nerve damage. Fluorescein angiography demonstrated no vascular leakage and electroretinography was normal in all of the eyes at two weeks. Histopathologic evaluation of the eyes at 7 and 14 days after injection revealed localized cellular inflammation in the vitreous and adjacent retina when MAP was used undiluted, but no reaction in the control eyes or in eyes injected with MAP at 1:10 dilution. This preliminary study suggests that MAP produces a marked intraocular inflammatory reaction when used at full concentration. By diluting the adhesive, a less severe inflammatory response was observed, which cleared with no complications.

Animals↗

Deletion mutagenesis of the ice nucleation gene from Pseudomonas syringae S203.

The ice nucleation gene inaZ, from Pseudomonas syringae S203, was manipulated to produce a series of defined rearrangements in its coding sequence without changing the reading frame. The effects of these mutations on the ice nucleation phenotype were determined in a heterologous host, Escherichia coli K12. Deletions which disrupted the periodicity of 16 codons, in a repetitive region of inaZ, caused the frequencies of ice nuclei in the bacterial population to be significantly depressed; the nuclei with thresholds at warmer temperatures were most affected. In contrast, when the periodicity was left intact, deletions and duplications in the same region had only slight effects on nucleation activity. Deletions removing part or all of one of the nonrepetitive regions (that encoding the amino-terminal domain of the InaZ protein) did not abolish nucleation activity, but caused it to be limited to cooler threshold temperatures. In contrast, the non-repetitive carboxy-terminal domain of the InaZ protein was shown to be essential for ice nucleation at all temperatures. The differential requirements (for periodicity, and for the amino-terminus) in forming nuclei with different thresholds may be significant for understanding what determines the threshold temperature of an ice nucleus.

Amino Acid Sequence↗

Orbital myositis involving the oblique muscles. An echographic study.

Idiopathic orbital myositis is a common nonspecific orbital inflammatory syndrome that can involve one or more of the extraocular muscles. Oblique muscle involvement is infrequently reported, possibly because such involvement is difficult to identify clinically or by computed tomography (CT). The authors reviewed seven cases of orbital myositis involving the oblique muscles solely or in association with rectus muscle involvement. Standardized echography demonstrated homogeneous low-reflective enlargement, diagnostic of myositis, of the superior and inferior oblique muscles and tendons along their courses. The finding of massive inferior chemosis was associated with involvement of the inferior oblique muscle. Although the disease typically responds to therapy with systemic steroids, residual gaze restriction may occur. The oblique muscles may be frequently involved in idiopathic orbital myositis when evaluated by standardized orbital echography. In these cases, echography provides rapid, accurate, and reliable confirmation of the diagnosis of myositis, differentiates other orbital inflammatory diseases, and provides an objective measure of the therapeutic response.

Adult↗

Prevalence, pathophysiology, and treatment of rhegmatogenous retinal detachment in treated cytomegalovirus retinitis.

Seventeen patients with the acquired immune deficiency syndrome and cytomegalovirus retinitis were treated with the antiviral drug ganciclovir (9-[1,3-dihydroxy-2-propoxy-methyl]-guanine, DHPG). Eight eyes of five patients developed rhegmatogenous retinal detachment after initiation of treatment. Multiple breaks in areas of peripheral, healed, atrophic retina accounted for the detachments. All seven eyes that underwent surgery had extensive retinal detachments that were reattached with vitrectomy and silicone oil. Retinotomy and retinal tacks were necessary in two cases that were complicated by severe proliferative vitreoretinopathy. In the fellow eye of one patient, laser treatment was used prophylactically to wall off a peripheral patch of healed retinitis. Endoretinal biopsies and culture were taken in five eyes; evidence of persistent cytomegalovirus was seen in two cases despite concurrent and clinically effective antiviral therapy.

AIDS-Related Complex↗

Echographic localization of corticosteroids after periocular injection.

The location of repository corticosteroid after subtenon injection was determined in 24 patients with macular edema associated with uveitis or anterior segment surgery. Standardized A-scan and B-scan echography were performed immediately before and after each injection. Localization was compared after subtenon injection in either the superior or inferior temporal quadrants. Echography showed that corticosteroid was deposited within the subtenon space over the macula in 11 of 24 cases. The therapeutic response manifested by improvement in macular function may be related to the proximity of the corticosteroid to the macular area. Lack of therapeutic response to repository corticosteroids may be because of placement at a site relatively far from the target zone.

Adrenal Cortex Hormones↗

A study of crying in medically and surgically hospitalized patients.

In a prospective study of hospitalized patients referred to a psychiatry consultation service, 46 patients were referred for a presumed diagnosis of depression because crying was a prominent symptom. Psychiatric consultation determined that 20% had a psychiatric disorder only, 33% had a neurological disorder only, 43% had both psychiatric and neurological disorders, and 4% had a previously undescribed entity, "essential" crying. The most common neurological disorder in these crying patients was bilateral hemispheric dysfunction associated with dementia or delirium; the most common psychiatric disorder was major depression. Effective therapy for patients who cry depends on proper identification of the cause of crying.

Crying↗

Sweat sodium levels in adults with nasal polyps.

Nasal polyps occur in 10% of children and 48% of adults with cystic fibrosis. The prevalence of abnormal sweat tests and cystic fibrosis in adults with nasal polyps has not been reported. We therefore performed sweat tests on 35 adults with nasal polyposis seen in two allergists' office practice. Sweat sodium levels ranged from 12 to 65 mEq/L (median = 34). These were considered within the normal range for adults. Abnormal sweat tests and cystic fibrosis were not found in this series of adults with nasal polyps.

Adult↗

Procedural validity of an abbreviated version of the SADS/RDC diagnostic process.

Formal diagnostic systems such as the Research Diagnostic Criteria (RDC) and standardized diagnostic interviews such as the Schedule for Affective Disorders and Schizophrenia (SADS) have enhanced clinical psychiatric research over the past decade. Because of the cost and time factors, however, they are not routinely used in most clinical settings. The availability of reliable alternatives compatible with clinical practice would encourage more psychiatrists to engage in clinical research. This study describes the nature and procedural validity of two such alternatives based on the RDC. Acceptably accurate, less costly research diagnostic processes can be incorporated into clinically oriented short-term acute inpatient units.

Alcoholism↗

Nocturnal sleep and daytime alertness of aircrew after transmeridian flights.

The nocturnal sleep and daytime alertness of aircrew were studied by electroencephalography and the multiple sleep latency test. After a transmeridian flight from London to San Francisco, sleep onset was faster and, although there was increased wakefulness during the second half of the night, sleep duration and efficiency over the whole night were not changed. The progressive decrease in sleep latencies observed normally in the multiple sleep latency test during the morning continued throughout the day after arrival. Of the 13 subjects, 12 took a nap of around 1-h duration in the afternoon preceding the return flight. These naps would have been encouraged by the drowsiness at this time and facilitated by the departure of the aircraft being scheduled during the early evening. An early evening departure had the further advantage that the circadian increase in vigilance expected during the early part of the day would occur during the latter part of the return flight.

Adult↗

Comparison of physical and genetic properties of palindromic DNA sequences.

Some viable palindromic DNA sequences were found to cause an increase in the recovery of genetic recombinants. Although these palindromes contained no Chi sites, their presence in cis caused apparent recA+-dependent recombination to increase severalfold. This biological property did not correlate with the physical properties of the palindromes' extrusion of cruciform structures in vitro. Thus, two unrelated palindromes with similar effects on recombination in both Escherichia coli and Pseudomonas syringae displayed quite different kinetics of cruciform formation. In plasmids of native superhelical density, one palindrome underwent rapid cruciform formation at 55 degrees C, whereas the other did not form detectable cruciforms at any temperature. A shorter palindrome with similarly rapid kinetics of cruciform formation did not affect recombination detectably. The lack of a clear relationship between physical and genetic properties was also demonstrated in the case of longer, inviable palindromes. Here we found that the degree of asymmetry required in vivo to rescue a long palindrome from inviability far exceeded that required to kinetically prohibit cruciform extrusion in vitro.

Base Sequence↗

The effect of venom skin testing on venom RAST titers.

Venom RAST titers were measured in 20 insect-sensitive patients before and two to three weeks after skin testing with insect venoms to determine whether venom testing might cause a rise in venom IgE titers. No significant rise in venom-specific RAST titers for honey bee, wasp and yellow jacket venoms was observed.

Adolescent↗

Immune function in marathon runners.

Quantitative immunoglobulins (IgG, IgA, IgM) and leukocyte phagocytosis and killing were studied in 20 male marathon runners to determine if rigorous physical conditioning affects immune function. C3, C4, Properdin Factor B, T and B cells, and phytohemagglutinin and pokeweed mitogen stimulation of lymphocytes were determined in selected runners. Complete blood counts, including platelets, were obtained for the group. Mean immunoglobulin values for IgG, IgA and IgM were within normal limits. Ten runners (50%) had slightly low total lymphocyte counts (less than 1500/mm3). Leukocyte phagocytosis and killing was consistently normal. Nine marathoners felt that running had increased, and one felt that it had decreased their resistance to respiratory infections. This could not, however, be correlated with significant changes in immune parameters. We conclude that long distance running has no effect on immune function.

Adult↗

Prophylaxis of attacks of hereditary angioedema.

Danazol, an attentuated androgen, has been suggested as an effective agent for the prophylaxis of attacks of hereditary angioedema. Four patients, with a clinical history of hereditary angioedema and a demonstrated depression of the serum inhibitor of the first component of complement (C1 INH) and the fourth component of complement (C4), were entered into a study to determine the minimum effective dose of this agent. All four of the patients had been experiencing attacks at least monthly, but they had only six attacks during a total of 60 patient months of Danazol therapy. The minimum effective dose varied from 100 to 400 mg/day. The drug appeared to work by increasing the level of serum C1 INH which reached the normal range in two of four patients. Side effects were only the anticipated menstrual irregularities in the female patients. Danazol appears to be an efficacious drug for prophylaxis of hereditary angioedema.

Adult↗

Use of biofeedback in weaning paralyzed patients from respirators.

Two paralyzed patients who were being treated with mechanical respirators and in whom weaning with intermittent mandatory ventilation failed were treated with regular sessions of biofeedback. Their respiratory volumes were displayed to them on oscilloscopes at bedside. A plastic (Plexiglas) template was placed on the face of the oscilloscope with two horizontal strips of adhesive tape affixed to it; the patient had to achieve a certain tidal volume (TV) to push the tracing outside the space between the horizontal lines. During each session the highest TV achieved determined the target TV to be maintained during the next session. The application of treatment coincided with improved ventilation; both patients were eventually weaned.

Biofeedback, Psychology↗

Electroencephalographic abnormalities in suicidal patients.

Struve has suggested that paroxysmal EEG abnormality is considerably more frequent in suicidal psychiatric inpatients than in nonsuicidal psychiatric inpatients. In order to see if these observations were confirmed in other populations, the Zung Index of Potential Suicide and scalp EEG were administered to 216 consecutively admitted VA psychiatric inpatients. The results indicated only slightly greater EEG abnormality in suicidal patients (14.9%), than in nonsuicidal patients (6.6%) statistical analysis failed to support either a general association between overall EEG abnormality and suicidal behavior, or the specific association between paroxysmal EEG abnormality and suicidal behavior, reported by Struve. Some of the data suggested that further EEG observations might be worthwhile on patients in the Threatener subcategory of suicidal behavior.

Adolescent↗