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Biomedical subjects

M Montgomery

Publications and source records attributed to M Montgomery.

At least 37 records · Page 2Linked to original sources
PubMed1993

Different patterns of neuropathological disease in rhesus monkeys infected by simian immunodeficiency virus, and their relation to the humoral immune response.

The brains of 21 rhesus monkeys inoculated with SIVMAC251 were examined after intervals ranging from 3 to 27 months and compared with five uninoculated controls. Eighteen animals became infected and individually exhibited several distinct patterns of disease. Nine (50%) had largely intramural leptomeningeal venous infiltrates (LMVI) without multinucleate giant cells (MGC) or foamy macrophages. Three (17%) had only MGC lesions, involving the cerebral parenchyma. One had both patterns and five (33%) neither. The controls had sparse and tiny LMVI only, similar to three inoculated animals that did not become infected. Immunohistochemistry showed the predominance of T and B lymphocytes in LMVI and choroid plexus mononuclear lesions but a predominance of macrophages over lymphocytes in the MGC lesions. Specific disease patterns differed in their association with the humoral immune response. Animals with LMVI were all hypergammaglobulinaemic when killed compared to pre-inoculation levels, and the size of the change in serum immunoglobulin concentration was positively correlated with a quantitative index of LMVI density. Furthermore, their post-mortem lymph node histology was hyperplastic. In contrast, animals found at autopsy to have MGC brain lesions were hypogammaglobulinaemic compared to preinoculation. The results are consistent with two phases in SIV-associated disease: one characterized by LMVI and hypergammaglobulinaemia and another featuring MGC and hypogammaglobulinaemia.

Animals↗
PubMed1993

A multicenter, randomized, double-blind, placebo-controlled, dose-titration study of oral pilocarpine for treatment of radiation-induced xerostomia in head and neck cancer patients.

PURPOSE: To determine the efficacy and safety of pilocarpine hydrochloride for symptomatic relief of postradiation xerostomia symptoms and for saliva production in patients with head and neck cancer. PATIENTS AND METHODS: One hundred sixty-two head and neck cancer patients who had received at least 40 Gy of radiation (117 patients had received > 60 Gy) with clinically significant xerostomia were enrolled onto a randomized, double-blind, placebo-controlled, multi-center clinical investigation. Patients received 2.5-mg tablets for the first 4 weeks, 5.0-mg tablets for the second 4 weeks, and 10.0-mg tablets for the last 4 weeks of the 12-week study. Patients were allowed to titrate pilocarpine or placebo for improvement in symptoms or to reduce side effects. Patients were evaluated for symptomatic relief by questionnaires and visual analog scales (VAS), and for saliva production by sialometry. RESULTS: Pilocarpine produced a significant improvement (P = .035) in overall global assessments compared with placebo. There was a statistically significant (P = .020) decreased use of oral comfort agents such as artificial saliva, hard candy, and water. Values for symptomatic improvement in dryness approached significance (P = .057). There were statistically significant postdose improvements in whole and parotid salivary flow in pilocarpine treatment groups versus placebo. All pilocarpine dosages tested were judged to be safe. Adverse experiences were primarily sweating, rhinitis, headache, nausea, and urinary frequency, with the most common side effect being mild to moderate sweating. There were no serious drug-related adverse experiences in any of the pilocarpine treatment groups. CONCLUSION: It is concluded that pilocarpine produces clinically significant benefits for the symptomatic treatment of postradiation xerostomia. Best results were obtained with continuous treatment for 8 to 12 weeks with doses greater than 2.5 mg three times per day.

Administration, Oral↗
PubMed1993

Conjugal amyotrophic lateral sclerosis: report of a young married couple.

We report a 38-year-old nurse who developed amyotrophic lateral sclerosis (ALS) beginning in September 1990. In May 1991, her 38-year-old husband developed dysarthria, which progressed to typical ALS. This is the fourth report in the literature of conjugal ALS occurring outside of Guam. Although this event is most likely due to coincidence, exogenous agents should be considered in the etiology of ALS.

Adult↗
PubMed1993

Hematopoietic stem cell deficit of transplanted bone marrow previously exposed to cytotoxic agents.

High-dose chemotherapy and/or total body irradiation followed by autologous bone marrow rescue has improved the survival of patients with a variety of malignancies. Candidates for autologous bone marrow transplantation (ABMT) often have received prior exposure to cytotoxic agents, some of which may damage primitive stem cells. We have developed an in vivo murine model to evaluate the effects of a number of individual cytotoxic agents on the ability of syngeneic donor marrow to provide long-term hematopoiesis in recipients following high-dose total body irradiation. Marrow was experimentally obtained by giving donor mice 6 weekly injections of saline, cytosine arabinoside, cyclophosphamide, cisplatin, 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), or busulfan, drugs known to have differing effects on primitive hematopoietic stem cells. After time to allow recovery of marrow and peripheral blood counts, 1 x 10(7) marrow cells from these mice were transplanted into lethally irradiated syngeneic recipients. Five to 6 months after marrow transplantation, the quality of long-term hematopoietic recovery was measured by WBC counts, marrow cellularity, CFU-S content, and determinations of stem cell self-renewal. Abnormalities were noted with the use of donor marrow exposed to all cytotoxic agents. Recipients of marrow previously exposed to cytosine arabinoside, an agent that spares the most primitive stem cells, were the least affected. Recipients of marrow previously exposed to busulfan, an agent known to damage primitive stem cells, were most affected with a decrease in peripheral blood counts, marrow cellularity, stem cell content, self-renewal capacity, and long-term survival. A decrease in hematopoietic stem cell self-renewal was seen in recipients of marrow previously exposed to cyclophosphamide, cisplatin, and BCNU even when marrow cellularity and CFU-S content were normal. These data suggest that the capacity of syngeneic donor marrow to provide long-term hematopoiesis in lethally irradiated recipients is dependent on its donor marrow primitive stem cell content. Long-term hematopoiesis may be severely compromised in recipients of donor stem cells previously exposed to cytotoxic agents which damage primitive stem cells.

Animals↗
PubMed1991

Relationship between response to inhaled salbutamol and methacholine bronchial provocation in children with suspected asthma.

Fifty children (27 females, 23 males) ages 6-15 years who were referred for evaluation of suspected asthma had baseline FEV1 and FEF25-75 of greater than or equal to 80% and FEF50 greater than or equal to 70% of predicted values. All had these tests repeated on the same day, after inhaling salbutamol. On a subsequent day PC-20 (methacholine) was determined as an index of bronchial hyperreactivity (BH). Fourteen age-matched healthy children (6 females, 8 males) were studied in a similar manner. There was no significant relationship between the PC20 and the change in FEF25-75 or FEF50 following salbutamol. There was a negative correlation between the initial FEV1 (% predicted) and the percent change in FEV1 following salbutamol (P less than 0.01). An increase in FEV1 of greater than 6% occurred in 7/12 (58.3%) patients with PC20 less than or equal to 0.25 mg/mL (Group I); in 7/24 (29.2%) patients with PC20 = 0.26-2.0 mg/mL (Group II); in only 1/14 (7.1%) patients with PC20 greater than 2.1 mg/mL (Group III) and in none of those asymptomatic (control) children with PC20 greater than 8.0 mg/mL (Group IV). All subjects who had a change in FEV1 greater than 6% after salbutamol had a PC20 less than 8 mg/mL and this test detected the majority of patients with severe BH. However, although the sensitivity of the test was 100%, the predictive value was only 36%. We conclude that in the presence of a normal baseline FEV1 a change of greater than 6% following salbutamol inhalation is indicative of bronchial hyperreactivity.

Administration, Inhalation↗
PubMed1990

[The effect of ipratropium bromide on lung function in patients with cystic fibrosis].

The main manifestation of cystic fibrosis (CF) of the lungs is an obstructive ventilation disturbance. The fact that the administration of atropine improves pulmonary function in patients with CF suggests a vagal mechanism for the development of bronchal obstruction. In a single-blind, placebo-controlled study, we investigated the effect of 250 micrograms of an inhalation solution of the anticholinergic substance ipatropium bromide (IB) on the pulmonary function of 11 patients with CF (age range: 8 to 29 years). The mean figures for the changes in FEV1.0, FEF25-75%, RV and TLC after inhalation of IB and placebo did not differ significantly. However, FEV1.0 and FEF25-75% after administration of IB increased in 4 out of 11 patients, and decreased in one. The lung volumes changed significantly in only a single case. This variable effect of inhaled IB in CF patients is in agreement with findings that have been observed for other substances with a "bronchodilatory" effect in patients with CF.

Administration, Inhalation↗
PubMed1989

Home measurement of oxygen saturation during sleep in patients with cystic fibrosis.

Feasibility and reproducibility of home measurement of arterial oxygen saturation (SaO2) were evaluated in 14 clinically stable patients with cystic fibrosis (CF). Changes in SaO2 during sleep were compared to the clinical status and pulmonary function while awake to identify predictors of nocturnal oxyhemoglobin desaturation. Each patient was assessed by clinical score, spirometry, and arterial blood gas analysis within 72 hours of the overnight study. Eight patients were studied on more than one occasion to assess dependence of SaO2 on position and reproducibility of overnight studies. A pulse oximeter stored up to 8 hours of nocturnal SaO2 measurements in its memory. Off-line analysis of trend data provided the proportion of sleep with SaO2 less than 90% and less than 85%. We found that patients with daytime PaO2 less than 60 mm Hg spent greater than 80% of their sleep with SaO2 less than 90%, while those with PaO2 greater than 70 mm Hg spent less than 20% of the night with SaO2 less than 90%. Patients with daytime PaO2 of 67-70 mm Hg were desaturated to less than 90%, from 0 to 98% of the night. No consistent body position dependence of daytime SaO2 was found. Home measurement of SaO2 during sleep was reproducible, with a difference on two repeat occasions of 4% +/- 2 (mean +/- SEM) for %time with SaO2 less than 90% and 3% +/- 2 for %time with SaO2 less than 85%. The severity of hemoglobin desaturation during sleep could not be reliably predicted from clinical scores or awake pulmonary function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Effect of terfenadine on the response to exercise and cold air in asthma.

To assess the role of histamine as a mediator in the response to exercise and isocapnic hyperventilation of cold air (IHCA) in asthma, we studied nine asthmatic subjects, age 13 to 25 years. All had exercise induced asthma (EIA) and positive responses to IHCA. Baseline lung function was measured before standardized challenges with histamine, exercise and IHCA. On separate days, these tests were repeated 3 h after a single oral dose of 120 mg terfenadine (TF). Histamine responsiveness decreased significantly, with a provocative concentration, producing a greater than or equal to 20% fall in FEV1 (PC20), of 1.1 +/- 0.8 mg/ml (mean +/- SEM) before and 12.0 +/- 4.9 mg/ml after the antihistamine. EIA was significantly less after TF, with 53 +/- 5% mean maximal falls in FEV1 from baseline before, and 29 +/- 9% after treatment (P less than 0.01, paired t-test). In contrast, the effect of TF on the response to IHCA was insignificant, with mean maximal falls of 45 +/- 7% in FEV1 before, and 41 +/- 7% after treatment. There was a correlation between PC20 and lowest FEV1 (% predicted) for EIA (r = 0.56, P less than 0.05), but not for IHCA (r = 0.34, NS). This study indicates a role of histamine as a mediator in EIA but not in IHCA, supporting different mechanisms for both stimuli.

Adolescent↗
PubMed1987

Nomenclature used by health care professionals to describe breath sounds in asthma.

We studied the spontaneous, uninstructed description by 40 health care professionals of breath sounds in asthmatic patients, and their use of lung sound terminology following current recommendations. Tape play-back auscultation of recorded tracheal and lung sounds was performed by ten observers in each group of residents, nurses, staff physicians and physiotherapists. They repeated the test after two weeks to three months. Individual descriptions were compared to computer-aided characterization of the breath sound recordings. We found significant differences in the preferred terms for description of adventitious lung sounds between the groups of health care professionals. There was considerable intraobserver variability, with less agreement when suggestions for a more complex characterization were followed. Our observations indicate the importance of teaching a standardized nomenclature for lung sounds to health care professionals, using only terms which are clearly informative of pulmonary disease.

Allied Health Personnel↗
PubMed1984

Elevated urinary excretion of 18-oxocortisol in glucocorticoid-suppressible aldosteronism.

A radioimmunoassay procedure for the measurement of urinary 18-oxocortisol was developed. The antibody was raised against 18-oxocortisol 3-carboxymethyloxime-BSA and had relatively high specificity, except for aldosterone (26.3%). The RIA required a preliminary HPLC purification using a Lichrosorb diol column eluted with toluene:acetonitrile:isopropanol:acetic acid (83:11.9:5.1:0.01). The eluate portion corresponding to 18-oxocortisol was evaporated and subjected to RIA. The RIA procedure had an intraassay variability of 11% when using a pool containing 10.8 micrograms/24 hr (n = 6) and 17% with a pool containing 3.28 micrograms/24 hr. The interassay variability was 11% (n = 4). The recovery of added 18-oxocortisol was 90 +/- 10%. The urinary excretion of 18-oxocortisol in 22 white normal subjects was 3.26 +/- 1.98 (SD) micrograms/24 hr (range 0.8 to 7.1 micrograms/24 hr). The mean excretion of 18-oxocortisol in 4 patients with glucocorticoid-suppressible aldosteronism (GSA) was 38.6 micrograms/24 hr (range 25.5 to 54.6 micrograms/24 hr). The excretion of 18-oxocortisol in 3 patients with adenomas producing primary aldosteronism (APA) varied between 11.1 to 17.3 micrograms/24 hr and in 3 patients with idiopathic aldosteronism (IA) varied between 2.5 to 10.6 micrograms/24 hr. 18-Oxocortisol excretion is increased markedly in the urine of patients with GSA: what role this relatively weak mineralocorticoid plays in the pathogenesis of their hypertension is unknown. Its elevation is probably a reflection of a postulated lack of involution of the 18-methyloxidase in the inner layers of the adrenal.

Glucocorticoids↗
PubMed1978

Primary hypothyroidism and pituitary insufficiency.

A 40-year-old man with primary hypothyroidism and sellar enlargement is described. There was deficiency of all pituitary tropic hormones except TSH which was elevated. TRH stimulation revealed responsiveness of pituitary thyrotropic cells, and thyroxine administration suppressed the elevated TSH. These findings are compatible with either a TSH-producing chromophobe adenoma resulting from primary hypothyroidism or, because of the suppressibility of the TSH secretion, thyrotropic hyperplasia secondary to hypothyroidism maintaining TSH secretion in the face of a non-TSH-secreting pituitary tumor.

Adult↗
PubMed1977

Somatosensory determinants of lordosis in female rats: behavioral definition of the estrogen effect.

By coating the ventral surface of male rats with a dye, regions of contact between male and female during male mounting were recorded precisely on the female's hair and skin. The male rat touches the female's flanks, rump, tailbase, perineum, and perivaginal surfaces during the female's initiation and maintenance of lordosis. Film analyses showed that the male's paws and pelvic thrusting stimulate the female's skin with dominant frequencies between 10 and 20 per second. Somatosensory stimuli were applied by the experimenter to the female skin locations contacted by the male. Deflection of hair on the flanks or perineum alone did not cause lordosis. Light stimulation simultaneously on flanks and perineum caused lordosis only in some females given high estrogen dosages supplemented by progesterone. When flank stimuli were followed by pressure on the rump, tailbase, and perineum, lordosis was triggered reliably in hormone-treated females. Here the estrogen-dependence of the reflex was shown, and progesterone synergized with the estrogen effect. Among lordosis components, rump and head elevations in response to pressure stimuli on the rump, tailbase, and perineum appear to be hormone-sensitive. These results help to define the minimal cutaneous sensory requirement for lordosis. In turn, the estrogen effect on lordosis may be defined behaviorally as increased responsiveness to pressure on rump, tailbase, and perineal skin, after flank stimulation. These results illustrate how estrogen, progesterone, and somatosensory stimuli interact in causing lordosis, increases in the strength of one factor compensating for decreases in another.

Animals↗
PubMed1976

Polyuria associated with an antibody to vasopressin.

1. A patient with polyuria in whom diabetes insipidus had been diagnosed was treated with Pitressin. Resistance to this therapy developed after 18 months and a circulating antibody to vasopressin was then demonstrated. Withdrawal of therapy led to a fall in titre of the antibody and an increase in maximal urinary concentration. 2. The antibody to vasopressin was associated with the IgA fraction of the serum immunoglobulins and its characteristics are described.

Adult↗
PubMedDate not supplied

Fecundability and husband's age.

The effect of husband's age on the probability of conception is evaluated from World Fertility Survey data in five developing countries: the Ivory Coast, Ghana Kenya, the Sudan, and Syria. Proportional hazards models, which include wife's age, husband's age, marriage duration, union type, and post-partum exposure as covariates, are used to describe the monthly conception rate for second and higher-order birth intervals in which no contraception was used. With the exception of Syria, the resulting models indicate that the effects of male age are generally small in relation to the influences of marital duration and the age of the woman.

Adult↗
PubMedDate not supplied

Gynecologic disorders in the older patient.

This review addresses the presentation and management of gynecologic disorders in older women. While these conditions are often managed by a primary caregiver, many women may present to the ED because they lack a primary gynecologic caregiver, their established gynecologic caregiver is not available, they are embarrassed to discuss their symptoms with an established caregiver, or they seek immediate relief of symptoms and reassurance. The emergency physician (EP) must be aware of the normal physiologic changes that occur with aging and how these changes may produce symptoms in older women. This review addresses physiologic changes and pathophysiologic conditions. Knowledge of these conditions and their management will facilitate reassurance of the patient, expedite appropriate initial therapy, and enable the EP to efficiently refer patients requiring further gynecologic assessment.

Aged↗