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Biomedical subjects

R J Baker

Publications and source records attributed to R J Baker.

At least 127 records · Page 7Linked to original sources
PubMed1978

Platelet metal levels in normal subjects determined by atomic absorption spectrophotometry.

A method has been developed for the estimation of iron, copper, zinc, calcium and magnesium in human platelets using atomic absorption spectrophotometry. Fe and Cu are either absent or present in very low concentration approaching the limit of detection: Zn, Ca and Mg are readily detectable. EDTA is preferable to ACD(A) or heparin as the anticoagulant for collection in that the platelet yield is reliable: however, slightly low results for Ca and Mg are obtained. Corrections for residual plasma and contaminating red cells are essential. Plasma and platelet metal levels in 33 normal subjects are reported together with the findings in four studies undertaken on platelets obtained from subjects with polycythemia vera.

Adult↗
PubMed1977

Monitoring in critically ill patients.

Although monitoring of critically ill patients has made giant steps forward in the past 15 years, such monitoring techniques must be viewed as a calculated risk, since a small but finite proportion of patients who are monitored by invasive techniques will suffer untoward and, occasionally, catastrophic consequences. Minimizing the risk involves careful general evaluation of the patient, adherence to strict indications for use of invasive techniques, and care coupled with experience in the actual manipulation. The specific procedure or procedures to be undertaken must be felt to be essential to the successful outcome of the care of the patient. The treatment of all critically ill patients must be individualized, and the monitoring techniques employed should be similarly individualized. With such a judicious approach, a great deal of valuable information can be obtained, and an effective and intelligent therapeutic regimen outlines so as to assure a successful outcome in as many patients as possible.

Angiography↗
PubMed1977

Persistence of antibiotics in milk from cows treated late in the dry period.

Nineteen cows were treated via intramammary infusion at various times prior to calving with one of two dry cow antibiotic preparations (cloxacillin or penicillin). Milk samples from these cows after calving were analyzed for antibiotic residues by the Sarcina lutea cylinder plate method. Eight cows were treated with cloxacillin was detected in the milk of only two cows after calving and then for only one milking, so no problem should exist with cloxacillin if the manufacturer's recommendations are followed. Penicillin residues were not detected in milk samples taken from cows treated more than 9 days prior to calving with the dry cow penicillin preparation. However, seven of nine cows treated with penicillin up to 9 days prior to calving had detectable penicillin residues in the milk from treated quarters after calving. Only one cow had detectable penicillin residues longer than the manufacturer's recommended milk withholding time of 96 h, and this cow was treated only 3 days prior to parturition. Normal routine on a dairy farm and adherence to manufacturer's recommendations should result in no antibiotic residue problems in milk from cows treated during the dry period for mastitis control with either cloxacillin or penicillin.

Animals↗
PubMed1977

The role of biliary scanning in the investigation of the surgically jaundiced patient.

The diagnostic accuracy of biliary scanning using 99mTc-pyridoxylideneglutamate has been determined in a series of 51 surgically jaundiced patients. This noninvasive technique was found to be safe, reliable and universally applicable in all instances of jaundice, regardless of the serum bilirubin value or prothrombin time. The results were found to compare favorably with those of other investigative procedures. It is suggested that the 99mTc-pyridoxylideneglutamate biliary scan is most advantageously carried out after clinical assessment and full biochemical evaluation of the patient. The scan result will indicate the next logical step in the management of the patient whether it be endoscopic retrograde cholangiopancreatography, percutaneous transhepatic cholangiography, biopsy of the liver or laparotomy.

Biliary Tract↗
PubMed1977

Biliary scanning with Tc-99m pyridoxylideneglutamate--the effect of food in normal subjects: concise communication.

Technetium-99m pyridoxylideneglutamate biliary scans were performed in 19 normal subjects in both the fasted and nonfasted state. The effect of eating was to reduce visualization of the gallbladder from 100% (fasted) to 47% (nonfasted). The common bile duct was seen in 84% on both occasions but intrahepatic and cystic ducts were seen less frequently in the nonfasted group. Preparation of patients by fasting is essential if information concerning gallbladder function is sought.

Adult↗
PubMed1976

Chromosome homology and evolution of emydid turtles.

G-, C-, Q-banding and standard karyotypic analyses were used to study the chromosomal relationships of emydid turtles. Ten species of emydids were used (5 batagurines and 5 emydines) which samples all of the karyotypic variation known for the Emydidae. Data from a testudinid and a chelydrid are compared to the emydids. The karyotype of Mauremys and Sacalia is considered representative of the primitive karyotype for this group because of its widespread occurrence in the morphologically primitive Batagurinae and its similarity to that of some testudinids. The emydine karyotype is believed to have evolved from the primitive batagurine karyotype by the deletion of a heterochromatic macrochromosome. Siebenrockiella and Rhinoclemys are karyotypically derived batagurines.

Animals↗
PubMed1976

Responses of rumen microflora to high-concentrate low-roughage diets containing whey products.

After 3 wk on a standardization ration of alfalfa hay and corn silage ad libitum and concentrate at 1 kg/3 kg milk, 15 lactating Holstein cows were fed 2.3 kg hay/day and one of five concentrate rations ad libitum for a 6-wk experiment. Cows were returned to the standardization ration after the experimental period. Concentrate rations during experimental period were: 1) control, 2) 14% dried whole whey, 3) 5.9% high mineral whey product, 4) 11.8% demineralized whey product, and 5) 9.8% lactose. Ration 3 contained the same amount of minerals from whey as ration 2 while rations 4 and 5 contained the same amounts of lactose as ration 2. Whey products replaced portions of corn and soybean meal in the rations. Total protozoa numbers in rumen contents averaged 1.8 X 105 /ml and were not different among times although they tended to be less during the experimental period on ration 4. Dasytricba decreased on rations 1, 2, and 4, while trends in numbers of Isotricha, Entodinium, and Diplodinium were not consistent. Only a few Ophryscolex were in a couple of the rumen samples. Bacterial numbers increased from 4.0 X 109/ml during standardization to 5.8 X 109/ml during the high-grain period, then returned to 3.8 X 109/ml in the post-experimental period. The number of lactose fermenters increased on all diets containing whey or whey products but not on the control diet. No differences in numbers of starch digesters were detected between times or among experimental rations because of large variations in numbers. Numbers of proteolytic organisms were not different among experimental rations but were generally lower during the post-experimental period.

Animal Feed↗
PubMed1976

Severe ischemia of the hand following radial artery catheterization.

Percutaneous radial artery catheterization for blood gas monitoring and continuous arterial pressure recording has become a common place procedure in the management of critically ill patients. Five patients with severe ischemia after cannulation have been encountered in the past 20 months, four of whom lost segments of one or more digits. Review of the events preceding and during radial artery cannulation allowed elucidation of the following principles: radial artery catheterization should be preceded always by a negative Allen test; the catheter should be removed after 12 to 18 hours, especially if the patient is critically ill, is hypercoagulable, or has impaired tissue perfusion; the superficial temporal artery is safer to use and permits long-term cannulation (5 to 7 days) without ill effect; and agressive approach to assessing flow and arterial reconstruction is essential if severe ischemic symptoms occur during or after radial artery catheterization. Ancillary measures, including cervicodorsal sympathetic block, intravenous low molecular weight dextran and heparin, and intra-arterial reserpine and fibrinolysin, may improve palmar circulation but should not be substituted for both noninvasive and angiographic study of arterial flow, followed by surgical restoration of flow, when indicated.

Aged↗
PubMed1975

Newer Techniques in evaluation of injured patients.

Effective management of the severely injured requires an experienced, knowledgeable, and thoughtful physician who has a rational approach to both evaluation and treatment firmly in mind. When in doubt, access to a Trauma Registry (computerized) can be exceedingly valuable to assist in selecting the most effective treatment for a given clinical problem. The evaluation of the patient centers about general metabolic considerations, including acid-base disequilibrium, respiratory insufficiency, fluid volume monitoring, tissue perfusion (urine output), and osmolality. Diagnostic efforts to identify organ injury include infusion pyelography, paracentesis, radionuclide scanning, and angiography. The most critical diagnostic evaluation, however, remains frequent, careful examination of the injured patient, meticulously noting and interpreting all changes in physical findings.

Abdominal Injuries↗