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Biomedical subjects

M J Harris

Publications and source records attributed to M J Harris.

At least 127 records · Page 7Linked to original sources
PubMed1989

Cortisone cure of the eyelid closure defect in lidgap-Stein fetal mice: a dose-response and time-response study as a test of the hypomorph hypothesis for the lidgap alleles.

The lidgap-Stein mutation is one of a series of alleles that cause the birth defect open eyes in mice. Previously it was known that cortisone administered during pregnancy prevents the defect in some lidgap-Stein fetuses. In this study, the hypothesis that lidgap-Stein is a hypomorph of effect intermediate between that of its alleles lidgap-Miller (least abnormal) and lidgap-Gates (most abnormal) was tested in a dose-response, time-response, and scanning electron microscopic study. Cortisone produced a response at doses of 20-80 mg/kg, with maximum cure of 30% in right eyes, 24% in left eyes, and 13% bilaterally. There was significantly more response in right than in left eyes. The response was slight at doses of less than 20 mg/kg and dropped to zero at the highest dose of 120 mg/kg. Treatment on days 13 or 14 gave the maximum response, with little or no response to treatment on days 10, 11, 12, 15, or 16. Severity of defect, measured as the size of gap in open eyes on day 18, was not reduced as the frequency of open eyes was reduced; most unclosed eyes remained wide open. The much lower level of maximum bilateral response to cortisone in lidgap-Stein (13%) than in lidgap-Miller (94%) is entirely compatible with the hypomorph hypothesis.

Alleles↗
PubMed1989

A scanning electron microscope study of fetal eyelid closure accelerated by cortisone in SWV/Bc mice.

Eyelid closure occurs earlier in SWV/Bc and CBA/J mouse fetuses whose mothers were treated with cortisone on day 14 of gestation than it does in fetuses from untreated mothers. Similar treatment prevents the open-eyes defect of lidgap-Miller mutant mice, but examination by scanning electron microscope (SEM) has shown differences in the periderm of the closing eyelids of the cortisone-treated mutant compared with those of untreated genetically normal fetuses. (Untreated mutant eyelids remain wide open and very abnormal). The present study has examined at the SEM level the accelerated eyelid closure of cortisone-treated normal strain, SWV/Bc, fetuses to investigate whether the differences from normal in the eyelids of treated lidgap-Miller fetuses are part of the mechanism of the cortisone "cure." At the SEM level, cortisone-accelerated eyelid closure of SWV/Bc fetuses is indistinguishable from that in untreated fetuses. This suggests that the early eyelid closure induced by cortisone in normal strain fetuses represents acceleration of the normal coordinated sequence of events that leads to closure, rather than an abnormality that fortuitously leads to closure. The data also indicate that the cellular abnormalities seen previously in treated lidgap-Miller mutant fetuses are a combination of 1) abnormalities due to the mutation that are not completely reversed by cortisone and 2) normal developmental stages that have become concurrent with the cortisone-induced late closure in lidgap-Miller mutant fetuses.

Animals↗
PubMed1989

Genetic analysis of the cause of exencephaly in the SELH/Bc mouse stock.

A new mouse stock, SELH/Bc, having a high liability to exencephaly has been developed. About 17% of SELH fetuses are exencephalic. The genetic cause of this exencephaly was investigated in a cross to a normal related ICR/Bc strain and in subsequent classical genetic crosses (F2, first and second backcrosses). The data were compared with a number of genetic models, including that of a single recessive mutation with 17% penetrance. The data did not fit single-locus inheritance. The expectations from the multifactorial threshold model based on an underlying quantitative liability trait with additive inheritance were found to fit the data very well. The number of loci involved was estimated to be about two or three. About 70% of exencephalic SELH fetuses are female, and there is no overall deficiency of males. The relatively higher risk in females was constant across the genetic backgrounds in the experiment. In summary, the liability to exencephaly in SELH mice appears to be a multifactorial threshold trait, and it therefore resembles human neural tube defects in type of genetic etiology. SELH therefore may be a valuable animal model in the study of neural tube defects.

Animals↗
PubMed1989

Instrumental assessment of lingual motor instability in tardive dyskinesia.

Instrumental measurement of fine tongue instability was carried out in 28 psychiatric patients (13 with and 15 without tardive dyskinesia [TD]) and 11 normal controls. All of the 13 TD patients and 4 of the 15 non-TD patients had instability of tongue greater than 2 standard deviations of the normal control mean. The tongue instability correlated with lingual (but not total body) dyskinesia rating and with age in the psychiatric patients. Our findings suggest that spectral analysis of fine tongue position is sensitive to overt as well as subclinical dyskinesia associated with neuroleptic usage.

Antipsychotic Agents↗
PubMed1989

The effects of a mother's second pregnancy on the firstborn child.

Mothers in the last trimester of the second pregnancy admit to being less active, more tired and moody than previously. Many were more anxious than usual. Their first child frequently showed behavioural changes. Those surveyed were between 1 1/2 and 4 years of age and showed more clinging, sleep disturbance and misbehaviour with tantrums than expected. It is presumed that the mother's pregnancy induces anxiety in her child with consequent behavioural changes.

Anxiety↗
PubMed1989

Recognition and treatment of depression in Alzheimer's disease.

Although there is no generally effective treatment for Alzheimer's disease, some common psychiatric symptoms associated with the disease, including depression, may respond to pharmacological intervention. Recognition of the depression requires a high index of suspicion from the primary care physician and caregivers and a history from family members or other caregivers. Several groups of medications, including tricyclic antidepressants, monoamine oxidase inhibitors, and psychostimulants, have been used for treatment of depression in dementia patients. Generally, Alzheimer's patients require lower dosages of medication and longer drug treatment trials than younger patients treated for depression.

Aged↗
PubMed1989

Monochromatic endoillumination for epimacular membrane surgery.

We attempted to simultaneously increase visualization of epimacular membranes and minimize retinal phototoxicity by filtering the light of the endoilluminator during vitreous surgery. The monochromatic filters we employed to eliminate short wavelengths were not useful because they reduced the level of illumination. We advise using the lowest level of illumination possible and an ultraviolet/infrared filter over the light source when working close to the retinal surface. The filter can be adapted to replace the fluorescein filter in the Ocutome console to facilitate insertion and withdrawal.

Evaluation Studies as Topic↗
PubMed1988

Operating microscope-induced retinal phototoxicity during pars plana vitrectomy.

We treated two cases of retinal phototoxic damage created by the coaxial illumination of the operating microscope during vitrectomy surgery. These lesions were probably created at the end of the vitrectomy procedure, after intraocular manipulation had ceased. This critical period, while the sclerotomy sites were being closed, was estimated to last no longer than ten to 15 minutes. We recommend that the cornea be shielded during sclerotomy closure at the conclusion of those vitrectomy procedures with a clear liquid media and clear crystalline lens or pseudophakos.

Adult↗
PubMed1988

Quantitative analyses of voluntary orofacial motor control in schizophrenia and tardive dyskinesia.

This paper reports the results of an investigation of voluntary control of lip, jaw, and tongue movements in schizophrenic patients with and without tardive dyskinesia. The aims of the study were to determine if voluntary orofacial motor control is disrupted in schizophrenia and to evaluate the relationship between voluntary motor control deficits and selected neurological and behavioral variables. Twenty-two schizophrenic patients and 13 normal control subjects were studied. Of the patients, 11 had moderate to severe TD. Analyses were made of performance on pursuit tracking tasks to evaluate differences between TD and non-TD patients and between medicated and currently unmedicated patients. The results indicated significant group differences in voluntary orofacial motor control. The finding that many non-TD patients exhibited voluntary motor dyscontrol suggests that this may represent a disorder independent of the involuntary dyskinesia. The findings indicated that the level of neuroleptic and/or antiparkinsonian medication was unrelated to the degree of voluntary motor control impairment. The results are discussed in terms of probable neurophysiological mechanisms underlying the motor control deficits in schizophrenia.

Adult↗
PubMed1988

Water-stress-induced changes in the abscisic acid content of guard cells and other cells of Vicia faba L. leaves as determined by enzyme-amplified immunoassay.

A highly sensitive, solid-phase, enzyme-amplified immunoassay for the plant growth regulator (+)-abscisic acid (ABA) was developed. The assay sensitivity (0.2-10 fmol) was sufficient for analyzing free ABA in homogeneous tissue samples dissected from Vicia faba L. leaves. Eight hours after detached leaves had been desiccated to 10% loss of fresh weight, the bulk leaf ABA content increased from </=0.2 to 6.2 ng.(mg dry weight)(-1). Epidermal tissue, spongy parenchyma cells, and palisade parenchyma cells from this water-stressed leaf had the following ABA contents, respectively: 4.8, 9.4, and 9.0 ng.(mg dry weight)(-1). Guard cells, which respond to exogenous ABA by losing solutes and volume, were also assayed. When they were dissected from control (fully hydrated) leaves, their ABA content was approximately 0.7 fg.(cell pair)(-1) [[unk]0.2 ng.(mg dry weight)(-1)]. In contrast, the ABA content of guard cells of water-stressed leaves was approximately 17.7 fg.(cell pair)(-1). These results indicate that ABA accumulation in a highly stressed V. faba leaflet is generalized; guard cells contain only 0.15% of bulk leaf ABA. The time course for loss of ABA from guard cells of a floating epidermal peel was studied. There was little loss within 30 min, but after 4 hr, the ABA content was only 17% of the original value. These results indicate that the bulk of guard cell ABA is not readily diffusible (i.e., probably not apoplastic). The results also indicate that common laboratory procedures results in lowered guard cell ABA content.

Journal Article↗
PubMed1988

Late-onset schizophrenia: an overview.

Onset of schizophrenia after the age of 40 has been a controversial topic. We reviewed more than 30 publications (mainly from Europe) on this subject. Many of the studies had methodological shortcomings, including problems in precisely dating the onset of schizophrenia. Nonetheless, it appears that a certain proportion of patients present for the first time with diagnosable schizophrenia after age 40. Late-onset schizophrenia is characterized by paranoid symptomatology, a high female:male ratio, an elevated prevalence of hearing loss and ocular pathology, schizoid or paranoid traits in premorbid personality, a tendency toward chronicity, and symptomatic improvement with neuroleptics. Family studies suggest that the prevalence of schizophrenia in relatives of late-onset schizophrenic probands is higher than that in the general population, but lower than that in relatives of earlier-onset schizophrenic probands. We believe that late-onset schizophrenia is a valid entity (or group of entities). Studies of the course, biological associations, neuropsychological performance, and pharmacological characterization of late-onset schizophrenia are warranted.

Adult↗
PubMed1988

Drug-induced psychosis and depression in the elderly.

This article discusses drug-induced psychosis and depression in the elderly population. Selected reports with particular emphasis on the geriatric population are evaluated with histamine blockers, antiparkinson, anti-inflammatory, antituberculosis, antineoplastic, antidepressant, anticonvulsant, cardiac, antihypertensive, and steroid drugs. Particular emphasis is placed on possible mechanisms of these side effects and factors contributing to increased incidence in the elderly population. In review, the clinician is advised to use special caution when prescribing these agents in the elderly considering increasing patterns of drug-induced psychosis and depression.

Aged↗
PubMed1988

Cleft palate: more genetic lessons from mice.

Cleft palate occurred in high frequency (14%) in the F2 generation of the cross between two stocks of mice, LGG and SELH, neither of which produces more than 2% cleft palate. The cleft palate trait results from a new combination of alleles that is not present in either parental stock. The lack of cleft palate in the F2 generation after outcrosses of both parental stocks to other strains shows that this new combination of alleles has specific contributions from both parental strains, and also that there must be at least two loci involved. A deficiency of Mod-1 homozygotes in the SELH/LGG F2 adults suggests that one of the loci involved may be linked to Mod-1 and that the number of loci involved is few. Significantly more F2 males (19%) than females (9%) were affected with cleft palate. The data can be explained by a two-locus epistatic model with a dominant mutation (P) at one locus that causes cleft palate when not suppressed by or compensated for by a dominant allele (S) at a second locus. The parental stocks would be PPSS and ppss. In the F2 generation, the new combinations PPss and Ppss would express cleft palate, a total expected of 19%. Similar new combinations of alleles at two loci may explain some instances of high occurrence of cleft palate or other developmental threshold traits in previously unaffected human families.

Animals↗
PubMed1988

Late-onset schizophrenia. Studying clinical validity.

The authors compared clinical characteristics of 36 late-onset schizophrenic patients from four centers (hospitals in San Diego, Baltimore, Los Angeles, and Montreal). There was a preponderance of the paranoid type with bizarre delusions and auditory hallucinations, chronic course of illness, and response to relatively low doses of neuroleptics. A comparison of late-onset and younger schizophrenic patients revealed both similarities and differences between the two groups. The authors reviewed the relevant literature and discussed the implications for assessing the validity of the concept of late-onset schizophrenia. They believe that, although less common, late-onset schizophrenia is probably as valid an entity (or group of entities) as schizophrenia with onset before age 45.

Adult↗
PubMed1988

Clinical presentation of late-onset schizophrenia.

DSM-III-R defines late-onset schizophrenia as schizophrenia that begins after age 45. The authors describe five patients who met DSM-III-R criteria for this disorder. The characteristic features of the disorder include bizarre delusions (usually of a persecutory nature), auditory hallucinations, a history of normal functioning at least until age 45, and a deterioration in personal-social functioning after the onset of illness. Physical examination, routine laboratory tests, neuropsychological evaluation, and magnetic resonance imaging (MRI) scans did not suggest the presence of any diagnosable organic mental disorder. In each of the five cases, mood disorders, delusional (paranoid) disorder, and schizophrenia with onset before age 45 were also considered in the differential diagnosis and ruled out. The authors' case vignettes support the premise that late-onset schizophrenia is a clinically diagnosable entity. Cautions in the diagnosis and treatment of such patients are discussed.

Age Factors↗
PubMed1987

Job satisfaction among academic coordinators of clinical education in physical therapy.

The Academic Coordinator of Clinical Education is the physical therapy faculty member who is responsible for the clinical component of the curriculum. The responsibilities involved in the ACCE's job are such that ACCEs seem to be at risk for job dissatisfaction and burnout. The purpose of this descriptive study was to investigate the levels and patterns of job satisfaction among ACCEs in physical therapy. A questionnaire, including a 32-item job satisfaction inventory, was sent to the ACCE at each accredited entry-level education program for physical therapists and physical therapist assistants (N = 169). One hundred twelve (66.3%) responses were received and analyzed. Demographic characteristics of the respondents are reported. The results of the study showed that ACCEs, in general, expressed low levels of occupational dissatisfaction and burnout. Satisfaction with the aspects of the job involving self-esteem, achievement, and creativity seems to outweight dissatisfaction with the time available, the work load, and organizational efficiency. Those ACCEs with doctoral degrees expressed the highest levels of dissatisfaction and burnout. Those ACCEs working in entry-level master's degree programs expressed the lowest level of dissatisfaction; those in tenure-track positions expressed the lowest level of burnout. Factors contributing to job satisfaction and dissatisfaction are discussed.

Achievement↗
PubMed1987

Effectiveness of improved targeting efforts for influenza immunization in an ambulatory care setting.

Annual vaccination programs against influenza are aimed at decreasing the morbidity and mortality associated with an infection. Recent epidemics have resulted in 40,000 excess deaths reported. The success of an immunization program depends both on the composition of the annual vaccine and the targeting efficacy of the program. National estimates of targeting efficacy are reported at 20%. An evaluation performed in the author's ambulatory care practice in the spring of 1984 yielded an overall efficacy of 24% in targeting activities. Efforts to improve the targeting practices included enhanced practitioner and patient education about the vaccine, flagging of medication records for patients at risk, and adoption of CDC guidelines for categorizing patients based on the degree of risk. A subsequent evaluation in 1986 showed a significant improvement in targeting efficacy (40%; P less than .001). Subgroup analysis indicated that the targeting efficacy of the program was greatest for the high-risk patients (P less than .025). An overall immunization rate of at least 80% of patients at risk is our desired goal.

Adolescent↗