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Biomedical subjects

K Francis

Publications and source records attributed to K Francis.

At least 19 recordsLinked to original sources

Measures of clinical agreement for nominal and categorical data: the kappa coefficient.

The desire to determine the extent inter-rater measurements obtained in a clinical setting are free from measurement error and reflect true scores has spurned a renewed interest in assessment of reliability. The kappa coefficient is considered the statistic of choice to analyze the reliability of nominal and categorical types of data recorded on the same patient by more than one clinician. This paper presents a simple computer program written in PASCAL that can be used in a clinical environment to quickly determine the reliability of nominal or categorical data. This computer program calculates both weighted and non-weighted kappa coefficients with their corresponding standard errors as well as bias-correcting jackknife estimates of kappa for use with small sample sizes.

Data Interpretation, Statistical

A height-adjusted step test for predicting maximal oxygen consumption in males.

A suitable testing device that is generally favored for estimating maximal oxygen consumption (VO2max) under field conditions or in environments where testing equipment is limited is the step test. Recently a mathematical model was reported to standardize the height of stepping for individuals of various heights. The purpose of this study was to validate this model in males. Thirty-three men aged 18 to 47 (x = 28) performed each of three rate-specific step tests and a Bruce treadmill test. Direct measurements of VO2max obtained from the treadmill test were correlated with a 15 second recovery heart rates after three different step tests were performed at stepping frequencies of 22, 26 and 30 ascents/minute. The correlation coefficients for prediction of VO2max from the recovery heart rate and directly measured oxygen consumption were 0.77 at 22 and 0.81 at 26 and 30 ascents/minute. Each relationship was statistically significant at the p < 0.01 level. It can be concluded that the single-stage height adjusted step test provides an effective predictor of VO2max in males and can be used when more complex methods of clinical testing are unavailable or not feasible.

Adolescent

The use of the walk test for the development of exercise guidelines.

The general interest in the application of exercise testing to evaluate the work capacity or change in the functional ability of individuals has resulted in the development of a variety of non-invasive field tests such as the one-mile-walk test. Health professionals often find it difficult to incorporate the results of such a field test in a format that can be used to advise individuals about how to start a safe and effective exercise program. This paper presents a computer program written in BASIC that determines an individual's maximal aerobic work capacity from a one-mile-walk test and establishes safe walk/jog guidelines that can be used to enhance physical fitness. Results are summarized in tabular as well as graphical format. This program, coupled with a new understanding of the benefits of exercise, allows for much more effective and precise exercise programs that will result in the improvement of the cardiovascular system and enhance the likelihood of long-term compliance.

Adult

A simple height-specific and rate-specific step test for children.

Recently an anatomic model was reported for adults that standardized the platform height for step tests using an individual's stature and a specified hip angle. In order to determine if the model could be used to predict the platform height for children, platform heights were calculated and hip angles were measured in 146 boys and 140 girls ages 6 to 18 years who were divided into four age groups (6 to 8, 9 to 11, 12 to 15, and 16 to 18 years old). There were no statistical differences between measured and calculated hip angles in any of the age groups. In order to determine the validity for predicting maximal oxygen consumption from stepping using a calculated platform height, three step tests were employed using one platform height and stepping frequencies of 22, 26, or 30 ascents/min. Each of the tests was administered to 93 6- to 18-year-olds. Correlation coefficients between the 15-second recovery heart rate after stepping and maximal oxygen consumption measured on a treadmill were .80 at 30 ascents/min, .79 at 26 ascents/min, and .81 at 22 ascents/min. Each of the correlation coefficients was significant at the P less than .01 level. It can be concluded that the model is valid for standardizing the platform height for children for use with a single stage step test for estimating maximal oxygen consumption.

Adolescent

Heat illness in football players in Alabama.

Fall football practice in Alabama generally begins during the later months of summer during some of the hottest periods of the year. Exercise during these periods significantly exposes young athletes to risks of heat illness and possible death and is made even more dangerous while training in full football uniform. In order to delineate specific guidelines to reduce the risk of heat illness, optimal practice times and fluid replacement schedules were studied for the state of Alabama. A review of five-year climatological data (1984-1988) for the months of August and September were conducted for four geographic regions of the state. A study of the data revealed that there were no environmental combinations at any time periods during the month of August for any locale in the state that would be considered safe for outdoors practice in full uniform. Similar results were recorded for September for cities in the south-central portion of the state. There were only two time periods during which players could practice outdoor with extreme caution. The periods were at 0900 and 1800 hrs in the north-central and northern portions of the state. If practice is conducted outdoors in Alabama during August and September, copious amounts of water should be consumed prior to practice; frequent water breaks should be scheduled throughout practice at which time each player should consume 150 - 200 ml; and the player should be carefully monitored for signs of heat illness.

Football

Phase I clinical and pharmacological study of liposome-entrapped cis-bis-neodecanoato-trans-R,R-1,2-diaminocyclohexane platinum(II).

cis-Bis-neodecanoato-trans-R,R-1,2-diaminocyclohexaneplatinum++ +(II) (NDDP) is a liposome dependent cisplatin analogue since the liposome carrier is required for its i.v. administration and for its biological activity. A Phase I study of liposome entrapped NDDP (L-NDDP) was performed using a single i.v. injection every 4 weeks. L-NDDP was prepared and characterized at M. D. Anderson Cancer Center. The maximum tolerated dose of L-NDDP was 312.5 mg/m2. The dose-limiting toxicity was myelosuppression, affecting all three blood cell lineages. The granulocyte nadir occurred on days 14-18, and the platelet nadir consistently earlier (days 11-12). The median day of recovery of blood cell counts was day 21 (range, 18-32). Other toxicities included grade 2 nausea and vomiting, fever consisting of a single temperature spike in most patients, grade 1 diarrhea after 60% of courses, and grade 1-2 malaise lasting for 5-10 days after the infusion in 73% of courses. Transient alanine aminotransferase elevations without clinical relevance were common. No signs of renal dysfunction or ototoxicity were observed. One patient with a preexisting peripheral neuropathy showed some progression of the neuropathy after a cumulative dose of 1605 mg/m2. Except for fever and transient liver dysfunction, no liposome related side effects were observed in spite of the high doses of lipid administered. The blood clearance of L-NDDP fits a two-compartment model at lower doses and a single-compartment model at the maximum tolerated dose, suggesting that saturation of the reticuloendothelial organs occurs at the maximum tolerated dose. Two minimal responses were observed. L-NDDP has a toxicity profile similar to that of carboplatin. Phase II studies to address the issue of how the therapeutic index of platinum compounds is affected by liposome entrapment are being planned.

Antineoplastic Agents

Purification and characterization of two forms of hydrogenase isoenzyme 1 from Escherichia coli.

A hydrogenase associated with dihydrogen uptake (HUP hydrogenase) was purified from an Escherichia coli mutant (strain SE1100) defective in utilization of molybdate and thus fermentative dihydrogen production. This protein had two subunits with apparent molecular weights of 59,000 and 28,000 (form 1). An immunologically cross-reactive hydrogenase was also purified from E. coli K10 grown in glucose-minimal medium and harvested at the mid-exponential phase of growth. Upon purification to homogeneity, this hydrogenase contained only one subunit with an apparent molecular weight of 59,000 (form 2). The two forms of the HUP hydrogenase exhibited similar kinetic characteristics. The electrophoretic properties of the enzyme and its response to pH suggest that this HUP hydrogenase is the HYD1 isoenzyme. The HYD1 isoenzyme was the only hydrogenase detectable during the stationary phase of growth in E. coli grown in Mo-deficient medium.

Cell Fractionation

Anaerobic threshold.

The general interest in the application of exercise testing to evaluate the work capacity or change in the functional ability of individuals has resulted in the development of a variety of non-invasive tests and test parameters such as the anaerobic threshold. This paper presents a computer program written in BASIC that determines the anaerobic threshold from expired respiratory gases collected from an incremental exercise test. Results are summarized in tabular as well as graphical format. The use of the incremental exercise test in conjunction with this computer program provide another means of efficiently determining the exercise capability of the patient.

Algorithms

The use of the ventilatory anaerobic threshold for the development of exercise guidelines.

The general interest in the application of exercise testing to evaluate the work capacity or change in the functional ability of individuals has resulted in the development of a variety of noninvasive tests and test parameters such as the anaerobic threshold. This paper presents a computer program written in BASIC that determines the anaerobic threshold from expired respiratory gases collected from an incremental exercise test. Results are summarized in tabular as well as graphical format. The use of the incremental exercise test in conjunction with this computer program will provide another means of efficiently determining the exercise capability of the patient.

Anaerobic Threshold

Determination of functional aerobic capacity using the microcomputer.

The general interest in the application of exercise testing to evaluate the work capacity or change in the functional ability of individuals has resulted in the development of a variety of non-invasive tests and test protocols such as the Bruce Treadmill Protocol. This paper presents a computer program written in BASIC that determines an individuals functional work capacity and functional age from minutes completed during a Bruce Treadmill incremental exercise test. Results are summarized in tabular as well as graphical format. The use of the Bruce Treadmill protocol in conjunction with this computer program provides another means of efficiently determining the exercise capability and functional status of a patient.

Computer Systems

Height-adjusted, rate-specific, single-stage step test for predicting maximal oxygen consumption.

A suitable ergometer that is generally favored for estimating maximal oxygen consumption (VO2 max) under field conditions or in environments where testing equipment is limited is the step test. Recently a mathematical model was reported to standardize the height of stepping for individuals of various heights. We designed a study to validate this model using a three-minute single-stage step test for predicting VO2 max in women. Seventeen women aged 19 to 33 performed each of three rate-specific step tests and a Bruce treadmill test. Direct measurements of VO2 max obtained from the treadmill test were correlated with the 15 second recovery heart rates after three different step tests done at stepping frequencies of 22, 26, and 30 step-ups per minute. The correlation coefficients of prediction of VO2 max from 15 second recovery pulse counts and directly measured oxygen consumption were 0.74 at 22 step-ups/min, 0.77 at 30 step-ups/min, and 0.8 at 26 step-ups/min. Each relationship was significant at the P less than .01 level. It can be concluded that the single-stage step test described in this study provides an effective predictor of VO2 max in young women and can be used when more complex methods of laboratory testing are unavailable or not feasible.

Adult

Delivery room management of meconium staining of the amniotic fluid and the development of meconium aspiration syndrome.

A 1-year prospective survey of obstetric and pediatric management of meconium staining of the amniotic fluid in 464 patients was undertaken. Pharyngeal suctioning before delivery was performed using bulb syringe (N = 130), De Lee suction catheter (N = 186), or both (N = 98); endotracheal intubation after delivery was also done in 413 instances. Using any of the three suctioning techniques, no differences were seen in Apgar scores, respiratory rates, presence or absence of meconium on or below the vocal cords, or development of meconium aspiration syndrome (MAS). If meconium was present on the vocal cords, it was present below the vocal cords in 76% of the cases. If no meconium was visualized, it was found below the vocal cords in only 7% of the cases. Of the 142 infants with meconium below the vocal cords, 10% developed MAS and all 14 survived.

Amniotic Fluid

Methods of anaerobic power assessment (a statistical program for the IBM PC)

Many sports activities that involve brief, high-intensity exercise tend to be anaerobic. To improve or optimize anaerobic performance, assessment of anaerobic power is necessary. A variety of tests have been developed, three of which are used widely; these are the Margaria step test, the Wingate cycle ergometer test, and the 50-yd dash. Estimates of anaerobic power requiring a minimal amount of equipment can be obtained using field tests such as the 50-yd dash. More quantitative measurements can be made using the Margaria step test or the Wingate cycle ergometer test. Whereas these tests have identifiable limitations, they are relatively easy to administer and require only a minimum of equipment. Because maximal anaerobic power is a kind of work important in many common sports activities, the measurement of anaerobic power should be considered with other routine assessments for optimizing performance.

Computers