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Biomedical subjects

R M Rogers

Publications and source records attributed to R M Rogers.

At least 19 recordsLinked to original sources
PubMed1992

Effects of growth hormone on diaphragmatic recovery from malnutrition.

A 25% weight loss was induced in adult Fisher 344 rats by nutritional deprivation. Subsequently, normal feeding was resumed. Refed animals were divided into three groups and received recombinant human growth hormone (rhGH) injections during 5 wk of refeeding, saline injections during 5 wk of refeeding, or 9 wk of refeeding without injections. The effects of nutritional deprivation and the various refeeding protocols on the cross-sectional areas (CSA) of each of the four types of myofibers [typed immunohistochemically with antibodies against four myosin heavy chain (MHC) isoforms known to be present in the rat diaphragm] were determined. Malnutrition decreased the CSA of myofibers containing MHC2X, MHC2B, and MHC2A (i.e., fast myofibers), with the greatest effect on muscle mass being due to the atrophy of fibers containing MHC2X. Fibers containing MHC beta/slow failed to undergo malnutrition-induced atrophy. Whereas refeeding for 5 wk in the absence of rhGH allowed the recovery of CSA of fibers containing MHC2A, fibers containing MHC2B and MHC2X remained smaller than fibers of similar type in control animals. In contrast, 5 wk of refeeding supplemented with rhGH returned all fiber CSAs to control values. Even when refeeding alone was extended to 9 wk to allow for weight stabilization, the CSA of the fibers containing MHC2B and MHC2X remained smaller than similar fibers in control muscle. Serum insulin-like growth factor, a marker of malnutrition (R. Reeves and J. Elders, J. Nutr. 109: 613-620, 1979), was significantly decreased after nutritional deprivation and returned to normal after 5 wk of refeeding and GH supplementation.

Animals↗
PubMed1992

Is loss of body weight in chronic obstructive pulmonary disease patients with emphysema secondary to low tissue oxygenation?

The available clinical information to date does not support the hypothesis that tissue oxygen debt is the primary cause of the wasting process in the chronic obstructive pulmonary disease (COPD) patient population. However, this should not deter the 'believers' of the hypothesis from further investigation. The information outlined above supports the need for reconsideration of this clinical problem. Tissue oxygen requirements and utilization is a complex interplay of multiple variables. Likewise, the assessment of nutritional status in the setting of oxygen therapy is complicated by shifts in body fluid compartments independent of changes in the fat-free mass (FFM). Utilization of newer techniques will be required to resolve the contribution of low tissue oxygenation to the wasting process. The continued development of noninvasive methods for the assessment of tissue metabolism, cardiac function, and tissue energy requirements will allow investigators to further clarify the relationship between tissue oxygenation and metabolism in patients with COPD. Clinical trials designed to examine this issue must recognize the multiple effects of oxygen on all aspects of nutrient utilization, including caloric intake, needs, and tissue delivery. Failure to address all aspects of this system will lead to continued debate regarding the etiology of weight loss in the COPD patient population.

Clinical Trials as Topic↗
PubMed1992

Pulmonary function abnormalities in chronic severe cardiomyopathy preceding cardiac transplantation.

Pulmonary function data, including diffusing capacity, were evaluated in 56 patients with chronic severe cardiomyopathy before heart transplantation. Cardiac catheterization data were used to describe the relationship between cardiac and pulmonary function. Of 56 patients 44 had some abnormality in pulmonary function. The majority, 30 of 56, had a restrictive impairment alone. Of 28 patients in whom diffusing capacity was measured, 64% had a diffusion impairment. There was no association of pulmonary function impairment with type of cardiomyopathy or smoking history. Pulmonary capillary wedge pressure correlated positively with DLCO, but not with FVC or TLC. Cardiac index and ejection fraction did not correlate with diffusing capacity. This precardiac transplantation cardiomyopathy patient group demonstrated frequent pulmonary function abnormalities not previously recognized.

Adult↗
PubMed1992

Physiologic effects of oral supplemental feeding in malnourished patients with chronic obstructive pulmonary disease. A randomized control study.

The association between severe nutritional depletion and chronic obstructive pulmonary disease (COPD) has long been recognized. A potential therapeutic benefit to nutritional support was previously suggested by us in a pilot investigation. Subsequent studies have reported conflicting results regarding the role of nutritional therapy in this clinical population. We report a randomized controlled study of nutritional therapy in underweight patients with COPD that combines an initial inpatient investigation (controlled nutritional support) with a prolonged outpatient follow-up interval. Provision of adequate calorie and protein support, adjusted to metabolic requirements, resulted in weight gain (intervention = +2.4 kg versus control -0.5 kg), improved handgrip strength (intervention = +5.5 kg-force versus control -6.0 kg-force), expiratory muscle strength (intervention = +14.9 cm H2O versus control -9.2 cm H2O), and walking distance (intervention = +429 feet versus control -1.0 foot). Inspiratory muscle strength was also improved (intervention = +11.4 cm H2O versus control +4.8 cm H2O) although this did not quite reach statistical significance. We conclude that provision of adequate nutrient supply under controlled conditions results in significant clinical improvements in the COPD patient population. However, the intervention is costly, time-intensive, and of limited therapeutic magnitude. More detailed work of alternative outpatient strategies combined with additional rehabilitative measures is indicated to delineate the full therapeutic potential of nutritional support for this clinical population.

Basal Metabolism↗
PubMed1991

Serum and lavage lactate dehydrogenase isoenzymes in pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the accumulation of lipoproteinaceous material in the alveolar space. Serum lactate dehydrogenase (LDH) has been noted to be elevated in patients with PAP in previous studies. We sought to extend this observation in a series of patients with PAP by looking at total serum LDH concentrations and LDH isoenzyme fractions measured before and after whole lung lavage. Total LDH and LDH isoenzymes were also determined in the lavage effluent. Total serum LDH was elevated before lavage in 10 of 16 patients. Prelavage serum LDH and prelavage alveolar-arterial O2 gradient showed a significant correlation (r = 0.62, p less than 0.05). A decrease in serum LDH was found after lavage in all patients in whom postlavage data was available (paired t test, p less than 0.01, n = 11), although the magnitude of this decrease varied considerably. The isoenzyme pattern before lavage was isomorphic, and this pattern was unchanged after whole lung lavage. This was in marked contrast to the LDH isoenzyme pattern observed in the lavage effluent, which showed a lower percent LDH1 and LDH2 and a higher percent LDH3, LDH4, and LDH5 when compared with the corresponding prelavage isoenzyme percentages for serum (unpaired t test, p less than 0.001). There was no correlation between the total serum LDH concentration and the total lavage LDH concentration. These data confirm that elevated serum LDH is a common finding in PAP. Furthermore, the LDH elevation found consistently in the alveolar fluid points to this as the source of the serum LDH.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchoalveolar Lavage Fluid↗
PubMed1990

Inductance plethysmography measurement of CPAP-induced changes in end-expiratory lung volume.

The respiratory inductance plethysmograph (RIP) has recently gained popularity in both the research and clinical arenas for measuring tidal volume (VT) and changes in functional residual capacity (delta FRC). It is important however, to define the likelihood that individual RIP measurements of VT and delta FRC would be acceptably accurate (+/- 10%) for clinical and investigational purposes in spontaneously breathing individuals on continuous positive airway pressure (CPAP). Additionally, RIP accuracy has not been compared in these regards after calibration by two commonly employed techniques, the least squares (LSQ) and the quantitative diagnostic calibration (QDC) methods. We compared RIP with pneumotachographic (PTH) measurements of delta FRC and VT during spontaneous mouth breathing on 0-10 cmH2O CPAP. Comparisons were made after RIP calibration with both the LSQ (6 subjects) and QDC (7 subjects) methods. Measurements of delta FRC by RIPLSQ and RIPQDC were highly correlated with PTH measurements (r = 0.94 +/- 0.04 and r = 0.98 +/- 0.01 (SE), respectively). However, only an average of 30% of RIPQDC determinations per subject and 31.4% of RIPLSQ determinations per subject were accurate to +/- 10% of PTH values. An average of 55.2% (QDC) and 68.8% (LSQ) of VT determinations per subject were accurate to +/- 10% of PTH values. We conclude that in normal subjects, over a large number of determinations, RIP values for delta FRC and VT at elevated end-expiratory lung volume correlate well with PTH values. However, regardless of whether QDC or LSQ calibration is used, only about one-third of individual RIP determinations of delta FRC and one-half of two-thirds of VT measurements will be sufficiently accurate for clinical and investigational use.

Functional Residual Capacity↗
PubMed1990

Intensity versus type of affect elicited by dissociative cognitions in moderating acute pain.

75 undergraduates were trained to use cognitions that elicited either high or low pleasure, high or low fear, or received an expectancy manipulation. Groups high in pleasure showed greater tolerance for pressure pain than other treatment groups but did not differ from expectancy; differences were not found on discomfort ratings. Results were not attributable to differential compliance with instructions, perceived effectiveness of cognitions used, or the number of cognitions used. The percentage of time during stimulation that assigned cognitions were used appeared to mediate tolerance. Expectations for improved tolerance elicited by appealing cognitions and compelling placebos may also mediate tolerance.

Adolescent↗
PubMed1990

Nutritional assessment and support in chronic obstructive pulmonary disease.

Malnourished COPD patients demonstrate energy requirements significantly above predicted needs especially during activity. Recognition of this altered metabolic state is essential to the design of any nutritional intervention program. This factor alone, however, cannot explain the wasting syndrome observed in these patients. The elevated demands appear to combine with recognized factors which act to limit caloric intake. Nutritional repletion with calorie and protein supply proportional to demand is associated with weight gain, nitrogen retention, and improvement in physiologic parameters of muscle strength. Greater success of outpatient nutritional repletion in this population is dependent on alternative feeding strategies to deal with those symptoms which limit caloric intake, especially during a disease exacerbation. Future clinical research must explore these strategies before an adequate assessment of the risk and cost-benefit ratio of nutritional intervention can be determined. Additional work is indicated in techniques to identify those patients who would benefit from calorie supplementation as well as techniques to monitor the response of these individuals. Information gathered from the continued study of this population of stable outpatients with COPD will have wide application to the entire COPD patient population. This includes those patients with respiratory failure on mechanical ventilation, where numerous complicating factors makes the study of nutritional intervention and respiratory muscle function difficult.

Body Constitution↗
PubMed1989

Daily living with COPD. Self-help skills to improve functional ability.

Although patients with chronic obstructive pulmonary disease (COPD) experience many problems as a result of their disease, they can use numerous strategies to maximize functional ability and maintain health. Patients with COPD should be encouraged to learn more about their disease and use commonsense approaches to management. Referral to a pulmonary rehabilitation program that offers comprehensive assessment, individualized treatment, and access to support groups is also valuable. Rehabilitation programs often result in an improved capability for daily activities and a better quality of life.

Activities of Daily Living↗
PubMed1989

Improvement in alveolar macrophage migration after therapeutic whole lung lavage in pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the accumulation of lipoproteinaceous material in the alveolar space. Alveolar macrophages (AM) in this disease have been noted in the past to have abnormally decreased function. It is not known whether these abnormalities are reversible with treatment of the disease. In this study, the effect of therapeutic whole lung lavage (WLL) on AM migration in four patients with PAP was determined. Standard segmental bronchoalveolar lavage (BAL) was performed 1 day before and 6 days after WLL. AM recovered by BAL were assayed for migratory response to N-formyl-methionyl phenylalanine (FMP) and endotoxin-activated human serum (EAHS). As expected, migration toward both stimuli was decreased before WLL compared to a group of normal controls. After WLL, AM migration toward both stimuli was not only greater than before the WLL but also was greater than normal. In one patient, serial BAL over a period of 18 months showed a marked decline in AM migration coincident with a clinical relapse of the disease. Thus, the defect in AM function found in PAP is reversible with WLL but can recur if clinical remission is not sustained.

Cell Migration Inhibition↗
PubMed1989

Body weight in chronic obstructive pulmonary disease. The National Institutes of Health Intermittent Positive-Pressure Breathing Trial.

This study reviews the relationship between body weight, pulmonary function, and survival in the recent clinical trial of intermittent positive pressure breathing (IPPB). We related body weight, expressed as a percent of the ideal (%IBW), to the numerous other features of the disease recorded in this data set. Body weight was directly related to FEV1 (p = 0.0001), so that all subsequent analyses of body weight had to first consider FEV1. Mortality appeared to be influenced by body weight independent of FEV1. In patients with %FEV1 less than 35, mortality increased with decreasing body weight (p = 0.093), and this relationship was stronger in patients with %FEV1 35 to 47 (p = 0.048) and even stronger in patients with %FEV1 greater than 47 (p = 0.007). After adjusting for FEV1, body weight was a powerful positive correlate with exercise capacity (p = 0.0001). Body weight was also inversely related to %TLC (p = 0.0408) after adjusting for FEV1. Body weight was a powerful predictor of diffusing capacity (p = 0.0001) in patients with the same FEV1. These results support the hypothesis that factors related to nutritional status are an independent influence on the course of COPD.

Adult↗
PubMed1989

Ventilation and breathing pattern during progressive hypercapnia and hypoxia after human heart-lung transplantation.

The effects of human pulmonary denervation on the ventilatory responses to progressive hyperoxic hypercapnia and isocapnic hypoxia as well as the effect on resting breathing pattern were evaluated in nine female heart-lung transplant (H-LT) recipients. The results were compared to those obtained from 10 normal women of comparable age and stature. Testing was performed 2 to 37 months after H-LT (median, 7.5 months). Cardiac function was normal in all H-LT recipients. None of the patients had spirometric evidence of airway obstruction, while six had a restrictive pattern with forced vital capacities less than 80% of predicted values. Resting minute ventilation (VE), tidal volume (VT), and ventilatory drive (VT/TI) in the H-LT recipients were not significantly different from those of the normal subjects. Inspiratory time (TI), however, was significantly shorter in the H-LT patients (1.64 +/- 0.2 versus 2.09 +/- 0.13 s, p = 0.035), and resting breathing frequency (F) tended to be greater in the H-LT recipients (16.27 +/- 2.04 versus 12.82 +/- 0.53 breaths/min, p = 0.052). The overall ventilatory response to hypercapnia was reduced after H-LT (0.91 +/- 0.17 versus 1.5 +/- 0.27 L/min/mm Hg CO2, p less than 0.043), as was the F response (0.2 +/- 0.09 versus 0.65 +/- 0.13 breaths/min/mm Hg CO2, p less than 0.01). The VT and VT/TI responses to hypercapnia did not differ between the H-LT recipients and normal subjects. There were no significant differences between the two groups with respect to the responses to progressive hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Breathing during wakefulness and sleep after human heart-lung transplantation.

To study the effects of pulmonary denervation on breathing during sleep, sleep studies were conducted on seven heart-lung transplant recipients (H-LT) and a comparable number of sex-matched normal subjects of similar age. Four of the H-LT patients had a restrictive pattern on spirometry. The time since transplantation ranged from 45 to 1,102 days. There were no significant differences between the groups with respect to total sleep time or distribution of sleep stages. There were no significant differences between the H-LT recipients and normal subjects with respect to baseline awake oxyhemoglobin saturation (SaO2) or the nadirs of SaO2 during REM and non-REM sleep, the absolute number and frequency (number per hour of sleep) of apneas, hypopneas, desaturation events, both over the whole night of study or separately during non-REM and REM sleep. Across wakefulness and all sleep stages, the H-LT patients tended to have shorter total respiratory cycle times (Ttot) (p = 0.052) and more rapid breathing frequency (F) than the normal subjects. This was associated with significantly shorter inspiratory times (Tl) (p less than 0.001) and smaller duty cycles (Tl/Ttot) (p less than 0.005) in the H-LT recipients. During non-REM and REM sleep, F tended to be higher in the H-LT recipients with pulmonary restriction than in the nonrestricted patients. There were no significant differences between the H-LT recipients and the normal subjects with regard to the periodicity of breathing, either in terms of timing parameters or breath amplitude.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Oxygen consumption of the respiratory muscles in normal and in malnourished patients with chronic obstructive pulmonary disease.

Patients with severe chronic obstructive pulmonary disease (COPD) commonly experience weight loss. An increased energy expenditure for respiration might explain the increased caloric requirements and weight loss seen in this patient population. We measured the oxygen cost of augmenting ventilation (O2 cost) using an open circuit technique with dead-space stimulation of ventilation in nine normally nourished (greater than 90% ideal body weight) and in 10 malnourished (less than 90% ideal body weight) patients with COPD as well as in seven normal control subjects. O2 cost was significantly elevated in the malnourished patients with COPD (4.28 +/- 0.98 ml O2/L ventilation) relative to the normally nourished group (2.61 +/- 1.07) and the normal control subjects (1.23 +/- 0.51) (p less than 0.001). The measured resting energy expenditure (REEmeas) was also increased compared with predicted values (REEpred) in the malnourished population (REEmeas/REEpred = 94.57 +/- 6.21% for control subjects, 105.5 +/- 19.66% for normally nourished patients with COPD, and 119.4 +/- 11.69% for malnourished patients with COPD) (p less than 0.005). The malnourished population was characterized by a greater degree of hyperinflation (RV/TLC = 0.55 +/- 0.09 for normally nourished versus 0.69 +/- 0.06 for malnourished patients) and inspiratory muscle weakness (PImax = 51 +/- 16.5 for the normally nourished and 34 +/- 12.2 for the malnourished population). We conclude that malnourished patients with COPD are characterized by a relative increase in resting energy requirements and, specifically, increased energy requirements for augmenting ventilation. This increase in energy requirements may result from the increased mechanical work load associated with severe COPD and/or a reduced ventilatory muscle efficiency.

Aged↗
PubMed1988

DLco in COPD.

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Humans↗
PubMed1987

Prolonged spontaneous remission in a patient with untreated pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis is a relatively rare, diffuse lung disease for which whole lung bronchopulmonary lavage is an effective treatment. The possibility of spontaneous remission also exists, but few actual cases have been described. This report describes a 56-year-old woman in whom pulmonary alveolar proteinosis was diagnosed 18 years earlier and who had a prolonged spontaneous remission before presenting with disabling symptoms. The possibility of prolonged spontaneous remission, although unusual, needs to be kept in mind when therapeutic decisions are to be made in patients with pulmonary alveolar proteinosis.

Female↗