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Biomedical subjects

M B Brown

Publications and source records attributed to M B Brown.

At least 127 records · Page 7Linked to original sources
PubMed1990

Urodynamic tests for female geriatric urinary incontinence.

Most urodynamic tests currently in use in the evaluation of female urinary incontinence have not been applied to a community-based sample to determine their specificity. In this study of a random sample of noninstitutionalized elderly, 258 self-reported continent and 198 self-reported incontinent women sixty years and older, who participated in a household survey, underwent a clinic evaluation (history, physical examination, and urinalysis); of these 67 continent and 100 incontinent female respondents underwent urodynamic testing. The uroflowmetry, cystometry, and supine static urethral pressure profilometry (UPP) findings did not differ significantly between continent and incontinent subjects (whether based on a self-report or a clinician's diagnosis of urinary continence status). Standing static and dynamic UPP and lateral cystography showed significant differences between self-reported continent and incontinent respondents. The provocative stress test significantly distinguishes continence from incontinence, and stress incontinence from other types. The sensitivity of the provocative stress test was 39.5 percent, whereas its specificity is 98.5 percent. Urodynamic testing including uroflow study, static UPP, and lateral cystography should not be used as a screening test but rather selectively as a confirmatory test, and to determine the therapeutic approach, and to assess the outcome of therapy.

Aged↗
PubMed1990

Two-year incidence, remission, and change patterns of urinary incontinence in noninstitutionalized older adults.

In this study, patterns of urinary incontinence, its severity and types were studied by three sequential data collections at annual intervals. The data are from a panel survey of a probability sample of 1,956 noninstitutionalized persons aged 60 and over residing in Washtenaw County, Michigan, who were interviewed in their homes about urine loss. Based on these self-reports, the prevalence of urinary incontinence was 18.9% in men and 37.7% in women. One-year incidence rates of about 20% among women and about 10% among men were found. One-year remission rates were about 12% for women and about 30% for men. When becoming incontinent, respondents were most likely to develop mild incontinence. Those who changed their severity level were most likely to progress from mild to moderate.

Aged↗
PubMed1990

Identification of Mycoplasma felis and Mycoplasma gateae by an immunobinding assay.

An immunobinding assay capable of distinguishing between Mycoplasma felis and Mycoplasma gateae was developed. Nitrocellulose was used as the solid support. Polyclonal rabbit antiserum against M. felis or M. gateae was used in the assay. Binding of the specific rabbit antiserum was detected by alkaline phosphatase-conjugated goat anti-rabbit immunoglobulin and an alkaline phosphatase substrate (Nitro Blue Tetrazolium-5-bromo-4-chloro-3-indolyl phosphate). The immunobinding assay was effective in the detection of feline mycoplasmas on agar plates, on primary isolation plates, in broth cultures, and in mixed cultures. No cross-reactions were observed with other related mycoplasmal species. The assay was cheap to perform and easy to interpret, and it required little technical time.

Alkaline Phosphatase↗
PubMed1990

Differential regulation of serum immunoreactive luteinizing hormone and bioactive follicle-stimulating hormone by testosterone in early pubertal boys.

The microheterogeneity and bioassayable activity of serum FSH (B-FSH) can be regulated by exogenous GnRH in boys with idiopathic hypogonadotropic hypogonadism and by estrogen in a women with gonadal dysgenesis, presumably via hormonally mediated changes in the degree of FSH glycosylation. To test the hypothesis that testosterone (T) regulates the circulating forms of B-FSH, we raised the serum T levels of early pubertal boys to adult levels. In this model, high dose T inhibits the pubertal nocturnal augmentation of LH secretion, apparently through decreased GnRH secretion. This model allowed us to test a second hypothesis, that B-FSH is a sensitive indicator of hypothalamic GnRH release. The boys were studied on two consecutive weekends, during which they received either saline (S) or T infusions. Beginning at noon on the study day, after an overnight acclimatization, the boys received either S or T at 33% or 100% of the adult male production rate. Blood was sampled from 2000-0800 at 10-min intervals for immunoactive LH and FSH (I-FSH) and for B-FSH, as determined by the in vitro Sertoli cell aromatase induction assay, and at 30-min intervals for T. Gonadotropin levels were analyzed as mean hourly or 3-h concentrations and as pulse profiles by two established objective peak detection programs, Cluster and Detect. During S treatment, mean LH increased after the onset of sleep (P = 0.0006) and, after plateauing for several hours, declined to baseline in the early morning hours. Mean levels of B-FSH were also minimally (but significantly) increased after the onset of sleep (P = 0.046) and paralleled the decline noted for LH. Mean levels of I-FSH did not demonstrate a diurnal rhythm. The effect of T was gonadotropin specific. High dose T abolished the nocturnal elevation in mean LH concentrations, but had no effect on the nocturnal elevation of B-FSH (P less than 0.05) or on I-FSH levels. The LH pulse frequency was greatest from 2300-0450 h, during S treatment (P = 0.016). The pulse frequency of B-FSH was also minimally increased after the onset of sleep (P = 0.045). The T infusion abolished the nocturnal increase in LH pulse frequency, without an effect on B-FSH pulse frequency. B-FSH pulse frequency exceeded LH pulse frequency during S treatment (8.0 +/- 0.7 pulses/12 h vs. 5.5 +/- 0.4), and B-FSH pulses persisted throughout the night. The pulse amplitudes of LH and B-FSH were not affected by T.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1990

Antimicrobial resistance in streptococcal species isolated from bovine mammary glands.

Streptococcal species isolated from dairy cows with clinical mastitis were obtained from mastitis research workers in Florida, Louisiana, New York, Vermont, Washington, and West Virginia. Seventy-one streptococcal isolates were tested, including 39 strains of Streptococcus agalactiae, 21 strains of S dysgalactiae, and 11 strains of S uberis. The minimal inhibitory concentration of erythromycin, lincomycin, oxytetracycline, penicillin, spectinomycin, streptomycin, and tetracycline was determined for each isolate. Differences were not detected among strains with respect to geographic origin. None of the strains was resistant to penicillin. Lincomycin was the next most effective antimicrobial, with only 2 resistant strains of each streptococcal species. There were no differences among the streptococcal species with respect to resistance to either penicillin or lincomycin. Streptococcus uberis was more likely to be resistant to erythromycin than were S agalactiae and S dysgalactiae (P less than 0.02). Streptococcus agalactiae and S uberis had similar distributions for resistance to oxytetracycline, tetracycline, spectinomycin, and streptomycin. Strains of S dysgalactiae were more likely to have intermediate resistance to oxytetracycline and streptomycin than were strains of S agalactiae and S uberis, which were highly resistant to oxytetracycline and streptomycin (P less than 0.001). Differences were not detected among the streptococcal species with respect to resistance to spectinomycin. Resistance to multiple antimicrobials was observed in all streptococcal species tested. Although S dysgalactiae appeared to have a greater percentage of strains (73%) that were resistant to multiple antimicrobials than did S agalactiae (31%) or S uberis (45%), differences were not statistically significant.

Animals↗
PubMed1990

Sexual function in the elderly.

Little is known about sexual behavior among the elderly living in the community. Questions about sexual activity and its correlates were included in a clinic examination whose participants were identified by a household survey of a probability of Washtenaw County, Michigan, elderly, aged 60 years and over, on the medical, epidemiological, and social aspects of aging. Estimates of proportions based on responses at the clinic examination were also projected to the demographics of the household survey. The estimated proportions of individuals who are sexually active are 73.8% for married men and 55.8% for married women; among unmarried men and women the proportions are 31.1% and 5.3%, respectively. The levels decrease significantly with age in both genders. The estimated proportion of married men with erectile impotence is 35.3%. Significant associations were observed between having problems with mobility and the lack of sexual activity in both genders. The prevalence of impotency was significantly associated with a history of heart attack, urinary incontinence, and the use of sedatives. The consumption of at least one cup of coffee per day was significantly associated with a higher prevalence of sexual activity in women and with a higher potency rate in men.

Aged↗
PubMed1990

Correlation methods for the centering, rotation, and alignment of functional brain images.

Simple methods are described using correlation analysis to rotate functional brain images to a standard vertical orientation, identify the antero-posterior centerline, and align multiple images from the same brain level. Image rotation and centering are performed by determining the angle of rotation and centerline coordinate that result in maximal left-right correlation. Testing of this method on sets of multiple images acquired simultaneously through different brain levels suggests that the optimal rotation can be determined within 1 degree and the centerline within 0.3 mm. Spatial alignment of two or more images from the same brain level of a single subject is accomplished by finding the translation and rotation that yield the highest correlation between the images. Testing of the alignment method on sets of simultaneously acquired images at multiple brain levels suggests that the optimal translation can be determined within 0.45-0.69 mm and the optimal rotation within 0.8 degrees. These methods are completely objective and can easily be automated.

Aged↗
PubMed1989

Prevalence and outcome of surgery for female incontinence.

A 4.7 percent surgery rate to correct urine loss conditions was found by a large scale survey of sixty-year and older non-institutionalized women in a Michigan county. The initial postoperative results reported by the respondents were 74 percent complete continence and 23 percent partial relief. The long-term self-reported outcomes (two years or more post-surgery) were an absolute continence rate of 39 percent and 17 percent with mild incontinence (the median time since surgery was 12 years), whereas the short term (4-23 months, mean 7.1 months) absolute continence rate was 71 percent. The characteristics of the incontinence respondent who had previous surgery showed 70 percent having mixed stress-urge type of incontinence and 66 percent losing urine almost weekly or daily. Bladder emptying symptoms were reported by 30.4 percent of the continent previously-operated respondents compared with 13.0 percent of the incontinent previously-operated respondents. All continent respondents and 84 percent of the incontinent respondents believed that physicians can help people with a urine loss condition.

Aged↗
PubMed1989

Circannual cycles of luteinizing hormone and prolactin secretion in ewes during prolonged exposure to a fixed photoperiod: evidence for an endogenous reproductive rhythm.

Circulating patterns of luteinizing hormone (LH) and prolactin (PRL) were monitored for 5 yr in ewes maintained either outdoors in natural conditions or indoors in a fixed, short photoperiod (8L:16D). The ewes were ovariectomized and each was treated with a Silastic implant containing estradiol to provide a fixed negative feedback signal to the reproductive neuroendocrine axis. Serum concentrations of LH and PRL were subjected to a statistical algorithm developed for the purpose of detecting hormone cycles. In ewes maintained outdoors, serum concentrations of both hormones underwent high amplitude cycles with a period no different from 365 days. Among ewes maintained in the fixed photoperiod, unambiguous cycles of LH and PRL persisted through the 5 yr of exposure to short days. Period of these cycles differed from 365 days. Further, the LH cycles became desynchronized among ewes housed together and desynchronized with respect to the LH cycles in ewes kept outdoors. These findings document the existence of an endogenous circannual rhythm of reproductive neuroendocrine function in ewes.

Animals↗
PubMed1988

Regeneration and repair of myelinated fibers in sural-nerve biopsy specimens from patients with diabetic neuropathy treated with sorbinil.

There is reason to believe that diabetic neuropathy may be related to the accumulation of sorbitol in nerve tissue through an aldose reductase pathway from glucose. Short-term treatment with aldose reductase inhibitors improves nerve conduction in subjects with diabetes, but the effects of long-term treatment on the neuropathologic changes of diabetic neuropathy are unknown. To determine whether more prolonged aldose reductase inhibition reverses the underlying lesions that accompany symptomatic diabetic peripheral polyneuropathy, we performed a randomized, placebo-controlled, double-blind trial of the investigational aldose reductase inhibitor sorbinil (250 mg per day). Sural-nerve biopsy specimens obtained at base line and after one year from 16 diabetic patients with neuropathy were analyzed morphometrically in detail and compared with selected electrophysiologic and clinical indexes. In contrast to patients who received placebo, the 10 sorbinil-treated patients had a decrease of 41.8 +/- 8.0 percent in nerve sorbitol content (P less than 0.01) and a 3.8-fold increase in the percentage of regenerating myelinated nerve fibers (P less than 0.001), reflected by a 33 percent increase in the number of myelinated fibers per unit of cross-sectional area of nerve (P = 0.04). They also had quantitative improvement in terms of the degree of paranodal demyelination, segmental demyelination, and myelin wrinkling. The increase in the number of fibers was accompanied by electrophysiologic and clinical evidence of improved nerve function. We conclude that sorbinil, as a metabolic intervention targeted against a specific biochemical consequence of hyperglycemia, can improve the neuropathologic lesions of diabetic neuropathy.

Action Potentials↗
PubMed1988

Cerebral hypometabolism in progressive supranuclear palsy studied with positron emission tomography.

Progressive supranuclear palsy (PSP) is characterized by supranuclear palsy of gaze, axial dystonia, bradykinesia, rigidity, and a progressive dementia. Pathological changes in this disorder are generally restricted to subcortical structures, yet the type and range of cognitive deficits suggest the involvement of many cerebral regions. We examined the extent of functional impairment to cerebral cortical and subcortical structures as measured by the level of glucose metabolic activity at rest. Fourteen patients with PSP were compared to 21 normal volunteers of similar age using 18F-2-fluoro-2-deoxy-D-glucose and positron emission tomography. Glucose metabolism was reduced in the caudate nucleus, putamen, thalamus, pons, and cerebral cortex, but not in the cerebellum in the patients with PSP as compared to the normal subjects. Analysis of individual brain regions revealed significant declines in cerebral glucose utilization in most regions throughout the cerebral cortex, particularly those in the superior half of the frontal lobe. Declines in the most affected regions of cerebral cortex were greater than those in any single subcortical structure. Although using conventional neuropathological techniques the cerebral cortex appears to be unaffected in PSP, significant and pervasive functional impairments in both cortical and subcortical structures are present. These observations help to account for the constellation of cognitive symptoms in individual patients with PSP and the difficulty encountered in identifying a characteristic psychometric profile for this group of patients.

Aged↗
PubMed1988

Clinical and cystometric characteristics of continent and incontinent noninstitutionalized elderly.

A survey of the clinical and cystometric characteristics of continent and incontinent elderly subjects living in a community has not been reported previously. Household respondents identified initially from a random probability sample were invited to undergo a free clinic evaluation followed by an invitation to free urodynamic testing. Of the 1,955 household respondents 456 women and 298 men attended the clinic. From this group 169 women and 94 men accepted the urodynamic invitation. Cystometric studies reveal a significant difference between the over-all prevalence of uninhibited detrusor contraction between genders, 7.9 per cent for women and 35 per cent for men. The occurrence of uninhibited detrusor contractions is more prevalent among incontinent than continent subjects and this difference is marginally significant. There is no significant association between uninhibited detrusor contractions and symptoms of difficult bladder emptying, irritative symptoms, voiding frequency, nocturia and urodynamic diagnosis of outlet obstruction (normal or high pressure and poor flow) but there were significant associations with responses to questions about the delay in getting to a toilet. The mean bladder capacities of men and women do not differ significantly between the different age groups but the capacity is significantly smaller for those with uninhibited detrusor contractions. The post-void residual urine volume shows no association with the continence status. These findings raise questions regarding our conventional thinking as to the etiology of uninhibited detrusor contractions, especially in men, and of urinary incontinence in general.

Aged↗
PubMed1988

Urinary incontinence and psychological distress among older adults.

We examined the relationship between urinary incontinence and psychological distress in a sample of community-dwelling older adults. The data are from a probability sample of Washtenaw County, Michigan residents ages 60 years and older, who were interviewed in 1983 and 1984. A total of 747 women and 541 men were included in the analyses. Experiencing urinary incontinence, particularly in a severe form, was weakly related to depression, negative affect, and low life satisfaction. These relationships are partly explained by the fact that incontinent respondents are less healthy than are continent respondents.

Adaptation, Psychological↗
PubMed1988

Human circadian rhythms in temperature, trace metals, and blood variables.

The literature supports the concept that circadian changes in body temperature reflect changes in the thermoregulatory set point. We were interested in studying the relationship between the circadian rhythm in body temperature and 24-h variations in plasma concentrations of iron, zinc, circulating leukocyte counts, and plasma interleukin 1 (IL-1) activity. Eight healthy men were studied for two separate 48-h sessions. Rectal temperature, plasma iron and zinc concentrations, plasma IL-1 activity, circulating leukocyte counts, and several other blood variables were monitored. Circadian rhythms in temperature, trace metals, and various leukocyte populations were demonstrated. The 24-h pattern of changes in plasma concentrations of iron and zinc approximate an inverse relationship with rectal temperature. Although we were unable to detect any IL-1 activity in human plasma collected at 4-h intervals, the daily changes in plasma trace metal concentrations and the variations in leukocyte populations may provide indirect evidence for a daily variation in local (e.g., in liver) or central nervous system release of IL-1.

Adult↗
PubMed1988

Importance of changing photoperiod and melatonin secretory pattern in determining the length of the breeding season in the Suffolk ewe.

Three groups of ovariectomized Suffolk ewes bearing s.c. Silastic implants of oestradiol were subjected to a 90-day priming treatment of an inhibitory long photoperiod (16 h light/day; 16L:8D). On Day 0 of the experiment, they were moved to stimulatory photoperiods. One control group was transferred to 12L:12D and a second control group was transferred to 8L:16D; both groups remained in those photoperiods to determine the timing of reproductive induction and refractoriness. The experimental group was transferred to 12L:12D on Day 0 and then to 8L:16D on Day 55 to determine whether the further reduction in daylength could delay the development of refractoriness. Reproductive neuroendocrine condition was monitored by serum concentrations of LH and FSH. Both gonadotrophins remained elevated for a longer period of time in the experimental group receiving the second reduction in daylength than in either control group, indicating that the second photoperiodic drop delayed the onset of photorefractoriness. Measurement of 24-h patterns of circulating melatonin suggests that the prolonged stimulation of reproductive neuroendocrine activity in the experimental group resulted from a lengthening of the nocturnal melatonin rise. These findings indicate that refractoriness to an inductive photoperiod can be temporarily overcome by exposure to a shorter daylength, and that the change in duration of the nocturnal increase in melatonin secretion is important in photoperiodic signalling. Thus, in natural conditions, the decreasing autumnal daylength, and the resulting expansion of the nocturnal elevation in melatonin secretion, may be utilized to produce a breeding season of normal duration.

Animals↗
PubMed1988

Effects of source and washing of erythrocytes on growth of bacterial pathogens from the bovine mammary gland.

Effects of source and washing of RBC on quantitative growth and hemolytic zone sizes of common bacterial pathogens of the bovine mammary gland were evaluated. Blood samples used to prepare the blood agar media were obtained from 10 adult dairy cows, 10 dairy calves, and 10 sheep. Hemolytic zone sizes produced by Staphylococcus aureus were significantly (P less than 0.01) larger on blood agar prepared with washed RBC than on blood agar prepared with nonwashed RBC, regardless of RBC source. With the exception of Corynebacterium bovis, growth of all bacteria was equivalent or significantly higher on medium prepared with washed RBC, compared with that on medium prepared with nonwashed RBC, regardless of RBC source. Significantly higher numbers of C bovis (P less than 0.01) and Streptococcus agalactiae (P less than 0.01) were isolated on medium prepared with washed cow RBC. Significantly higher numbers of Str uberis (P less than 0.01) and S aureus (P less than 0.05) were isolated on medium prepared with washed sheep RBC and washed calf RBC, respectively. Growth of Escherichia coli was not affected by the RBC source. Seemingly, RBC used in the preparation of medium should be washed. The source of RBC, as well as inter-animal variation, also should be considered in the quality control of medium.

Animals↗
PubMed1987

Measurement of antibody to Mycoplasma hominis by an enzyme-linked immunoassay and detection of class-specific antibody responses in women with postpartum fever.

The standard conditions for detection of human IgG, IgM, and IgA antibodies to Mycoplasma hominis by an enzyme-linked immunosorbent assay (ELISA) were established with the use of a cell lysate antigen and alkaline phosphatase conjugates. Antigen was used at a concentration of 10 micrograms of protein per milliliter, sera were diluted 1:200, and conjugates were diluted 1:500. Agreement between cultured isolation of M. hominis from the lower genital tract and presence of antibody in 207 women was 71%, 82%, and 86% for IgG, IgM, and IgA, respectively. When the ELISA was compared with the mycoplasmacidal assay, an overall agreement of 81% occurred, with the majority of the discrepancies occurring in the ELISA-positive and mycoplasmacidal-negative category. A linear relationship between end point titer and the A400 value (ELISA or absorbance value at 400 nm) at a standard serum dilution was demonstrated for the IgG, IgM, and IgA classes. Although the ELISA was relatively independent of antigen heterogeneity, no single strain detected more than 87% of positive sera, thus suggesting that optimum detection of antibody to M. hominis by the ELISA will require use of antigen pools derived from multiple strains of M. hominis.

Antibodies, Bacterial↗