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Biomedical subjects

W H Howard

Publications and source records attributed to W H Howard.

At least 19 recordsLinked to original sources

Prescribing exercise for your patient.

The lack of exercise by most Americans is a major contributing factor to many chronic diseases. Physicians are now prescribing exercise for patients just as they would drugs. Compliance with any exercise program depends on realizing the needs and goals of the individual. The fundamental principles of an exercise prescription apply to all persons regardless of age, sex, or level of fitness. A systematic manipulation of the components of frequency, duration, intensity, and progression with periodic reevaluation allows the program to be individualized. The guidelines for the program should include all of the components of health-related physical fitness. These include cardiorespiratory endurance, body composition, muscular strength and endurance, and flexibility. A program for exercise should fit the lifestyle of the patient and be a life-long prescription.

Chronic Disease

Modified technique for dual chamber pacemaker insertion.

Insertion of a permanent dual chamber pacemaker by the Seldinger technique usually requires two needle punctures of the vein or the use of a large introducer, thus increasing the risks associated with this procedure. We describe a modified technique using a relatively small introducer and a single subclavian vein puncture that we have found to be safe and simple to perform.

Humans

Economics of mastitis control.

The frequency of use and the effects of mastitis control practices on SCC and milk yield were investigated. A survey of current management practices was combined with DHI production information to determine the relationship between milk yield, SCC, management practices, and production and producer characteristics under field conditions. The expected negative relationship between SCC and milk, fat, and protein yield was substantiated. The SCC for an individual cow was a better indicator of milk loss than was a bulk tank SCC. Most recommended mastitis control practices were estimated to be economically beneficial; however, using a sanitizer in the washing solution and having a company change the milking machine inflations were not economical. Questions were raised about the economic efficiency and efficacy of treating all cows as opposed to selected cows at drying off.

Animal Husbandry

Comparative feed efficiency of Holstein and Jersey cows.

Feed efficiency measures, gross energy (solids-corrected milk/estimated energy intake), N (milk N/N intake) utilization, and apparent digestibilities of ration dry matter and N were calculated for 34 daughters of 21 Holstein and 29 daughters of 18 Jersey sires in first and second trimesters of lactation. Cows were studied in N balance trials and were fed ad libitum corn silage-based, complete rations formulated to meet average nutrient requirements. The objective was to determine whether these breeds differ in rates of converting dietary protein or energy to milk protein or milk energy. Holstein and Jersey did not differ for digestibility of ration dry matter in either trimester of lactation. They also converted dietary protein to milk protein at similar rates. Energy efficiencies of Holstein and Jersey did not differ in first trimester, but Holstein exceeded Jersey in second trimester. Because intake of dry matter by Jersey increased about 4% from first to second trimester (opposite of Holstein) and N balance was higher than for Holstein, Jersey cows may have been repleting more adipose tissue. We suggest no comparative advantage for Jersey in spite of higher ratios of milk to body weight and feed intake less than Holstein.

Animals

Unilateral renal agenesis and other causes of the solitary photopenic renal fossa.

The differential diagnosis of a solitary photopenic defect in the renal fossa observed at renal scintigraphy is extensive. A case of one of the most unusual causes for this finding, renal agenesis, is presented. Additional cases that illustrate the similarity in the radionuclide appearance of other pathologic entities are also presented. Correlation with clinical findings and other imaging modalities is required to accurately distinguish these conditions.

Carcinoma, Renal Cell

Scintigraphic appearance of the piriformis muscle syndrome.

This is the first report in the nuclear medicine literature of the scintigraphic appearance of the piriformis muscle syndrome. This syndrome previously has been thought to be a purely clinical diagnosis and imaging modalities have been ignored. However, its confusing clinical presentation can lead to unnecessary surgical exploration. This case is presented to illustrate the characteristic scintigraphic pattern and suggest the role of nuclear medicine scanning in establishing the diagnosis.

Adult

Optimal technetium-99m RBC labeling for gastrointestinal hemorrhage study.

Four methods of Tc-99m red blood cell labeling were tested for labeling efficiency and kinetics in normal adults. From a perspective of the gastrointestinal hemorrhage study, the in vivo method was least appropriate because of extravascular loss of pertechnetate. The modified in vitro method was disadvantageous because of long labeling intervals in a syringe fixed to the patient's forearm (45 minutes). The pure in vitro methods produced the highest labeling efficiency (95% +) and are preferred by the authors.

Erythrocytes

Dual isotope scanning with gallium-67 citrate and technetium-99m radiopharmaceuticals.

The interpretation of Ga-67 scans is limited by the complex anatomic and physiologic distribution of Ga-67 and by the low resolution possible with this isotope. The use of a second isotope Tc-99m, tagged to an appropriate pharmaceutical allows the identification of anatomic landmarks. Computer acquisition of both the Ga-67 and Tc-99m images allows for subtraction of the Tc-99m images from the Ga-67 images and leads to precise localization of abnormal Ga-67 accumulations. Only a small percentage of the counts in the Tc-99m window are due to Ga-67 scatter and do not degrade the Tc-99m images. Cases illustrating the value of the dual-isotope technique are presented.

Abscess

Left ventricular volume determination from single-photon emission computed tomography.

To compare the accuracy of single-photon emission computed tomography (SPECT) with that of contrast cineangiography in measuring left ventricular end-diastolic volume, 25 consecutive patients undergoing catheterization for coronary artery or valvular heart disease were first evaluated scintigraphically. A simple, count-corrected voxel counting technique was used to derive left ventricular end-diastolic volume from transaxial SPECT slices. SPECT volume values showed a high degree of correlation with those determined by angiography (r = 0.969), with a standard error of the estimate of 23 ml. SPECT offers a highly accurate and essentially noninvasive method for measuring chamber volumes that is independent of geometric assumptions about ventricular configuration and chest wall attenuation and does not require blood sample counting.

Adult

Chest radionuclide angiography in the evaluation of pulmonary masses.

A retrospective analysis of 104 chest radionuclide angiography (CRNA) studies establishes the utility of this procedure in the evaluation of pulmonary malignancies and benign masses. Remarkable abnormalities in the perfusion of the lungs were identified in 36 (58%) of 62 cases that were not predictably normal or predictably abnormal form the clinical setting. While 60 of these 62 cases involved malignancy being evaluated for metastases, only 21 (34%) had metastases identified by radionuclide bone or liver-spleen scintigraphy. In addition to diagnosis of superior vena cava obstruction, the CRNA may have a more frequent application as an adjunct to routine scintigraphic studies directed to the identification of metastatic disease.

Adenocarcinoma

SPECT hepatic scintigraphy "hot spot" localization.

The authors report a case of "hot spot" localization on SPECT hepatic scintigraphy secondary to IVC obstruction. The tomographic slices demonstrated the location of the focal increase in radiotracer activity as anterior, within the medial segment of the left lobe of the liver. Radionuclide angiography confirmed the extensive collateral vasculature of IVC obstruction.

Humans

Biliary scintigraphy. The "hot rim" sign.

A new cholescintigraphic finding, the "hot rim" sign, is reported in a case of acute cholecystitis. Local inflammation in the gallbladder fossa may be the cause of this phenomenon.

Acute Disease

Fourier phase analysis in non-cyclic dynamic studies.

Single harmonic Fourier amplitude and phase (FA/P) analyses of 129 radionuclide angiographic (RNA) studies were found to reflect accurately the sequence and quantity of perfusion determined in the independently interpreted RNA studies. In addition, the anatomic detailing in peripheral studies (hands, feet, etc.) was considered superior to that obtained in RNA studies.

Adult