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Biomedical subjects

A Shenkin

Publications and source records attributed to A Shenkin.

At least 145 records · Page 8Linked to original sources
PubMed1980

Assay for trimethoprim in serum and urine by means of ion-pair chromatography.

We describe a rapid, precise, and reliable procedure for assay of trimethoprim in serum and urine by ion-pair chromatography. Trimethoprim concentrations in urine are determined by an externally standardized, direct-injection procedure; assay in serum involves a simple preliminary extraction and internal standardization. The assays are suitable for pharmacokinetic studies and have been applied to determination of trimethoprim concentrations in serum and urine during therapy with Co-trimoxazole, a sulfonamide/trimethoprim preparation.

Chromatography, Gas↗
PubMed1979

Assessment of nutritional status: the biochemical approach and its problems in liver disease.

The role of laboratory tests in the assessment of nutritional status is reviewed. Methods commonly used in evaluating adequacy of energy, protein, mineral and vitamin intake are discussed, and a protocol for nutritional assessment and monitoring is presented. The specific nutritional problems found in liver disease, and the effects these have on this protocol are considered.

Amino Acids↗
PubMed1979

Intra-individual variation in commonly analyzed serum constituents.

Concentrations of 27 commonly estimated serum constituents were measured in blood sampled from 20 apparently healthy volunteers at 0830, 1230, and 1630 hours on each of four days, at weekly intervals. Time-dependent statistically significant (p less than or equal to 0.01) variation was observed in 12 of the constituents. The 15 constituents that showed no statistically significant diurnal variation included the immunoglobulins, other specific proteins, enzymes, cholesterol, calcium, copper, and magnesium. On the different days of the study consistent temporal patterns were observed in urea, creatinine, phosphate, zinc, bilirubin, triglyceride, total protein, and albumin. The magnitude of variation was particularly great in potassium, iron, zinc, and bilirubin. In general, day-to-day changes in concentration exceeded within-day changes, except for potassium, phosphate, and zinc, for which greater changes could be observed within-day than from one day to another at the same time.

Alanine Transaminase↗
PubMed1978

Effect of dietary protein on urinary excretion of 3-methylhistidine in rat.

The excretion of the amino acid 3-methylhistidine in urine has been shown to be correlated with protein catabolism in skeletal muscle. In rats, 3-methylhistidine is partly acetylated (N-acetyl-3-methylhistidine) and it has been proposed that the relative amounts of 3-methylhistidine and N-acetyl-3-methylhistidine in urine is age dependent. In this experiment the effect of dietary protein quality on urine excretion of 3-methylhistidine and N-acetyl-3-methylhistidine was studied. Six groups of rats (mean weight 80 g) were fed diets containing 10% protein of different quality, the net protein utilization ranging from 76.7 for egg albumin to 28.9 for wheat gluten. The excretion of non-acetylated 3-methylhistidine was not dependent on the diet. There was, however, a good correlation between protein quality and total urine 3-methylhistidine (3-methylhistidine plus N-acetyl-3-methylhistidine), the higher the protein quality, the greater being the excretion of total 3-methylhistidine. The relative amounts of 3-methylhistidine and N-acetyl-3-methylhistidine correlated with the mean body weight, but not the age, of the animals. This study therefore demonstrates that a relationship exists between the nutritive quality of the dietary protein and the urinary excretion of 3-methylhistidine in rats.

Animals↗
PubMed1978

[General aspects of intravenous feeding of cancer patients].

In order to obtain or maintain a good nutritional status in cancer patients, it is often necessary to perform intravenous nutrition. In summary, several studies have indicated that intravenous nutrition may be beneficial in association with surgery, radiation, or chemotherapy in patients with cancer. More controlled studies, however, are required. There is no indication at the present time of any adverse effects of this method of treatment in relation to tumor growth. The general nutritional improvement in patients on intravenous nutrition increases the immunocompetence, resistance to radiation and cytostatics as well as the mood and quality of life of the cancer patients. In very broad terms this new intravenous nutrition therapy means that a cancer patient should not be left without specific cancer therapy because of starvation and its serious or even fatal complications.

Acidosis↗
PubMed1978

[General aspects concerning the intravenous feeding of cancer patients].

In order to obtain or maintain a good nutritional status in cancer patients, it is often necessary to perform intravenous nutrition. In summary, several studies have indicated that intravenous nutrition may be beneficial in association with surgery, radiation, or chemotherapy in patients with cancer. More controlled studies, however, are required. There is no indication at the present time of any adverse effects of this method of treatment in relation to tumor growth. The general nutritional improvement in patients on intravenous nutrition increases the immunocompetence, resistance to radiation and cytostatic as well as the mood and quality of life of the cancer patients. In very broad terms this new intravenous nutrition therapy means that a cancer patient should not be left without specific cancer therapy because of starvation and its serious or even fatal complications.

Acidosis↗
PubMed1977

Poly(A)-binding RNAs from nuclei and polysomes of BHK-21 cells.

The presence in nuclei and cytoplasm of cultured BHK-21/C13 cells (baby hamster fibroblasts) of RNA species with high affinity for poly(A) was detected using either a Millipore-poly(A)-binding assay or columns of poly(A)-Sepharose 4B. The nuclear species which labels rapidly is metabolically unstable and appears to be a specific subclass of heterogenous nuclear RNA. Digestion with T1 RNAase gives rise to a low level (1%) of oligonucleotide fragments of a disperse size range which are relatively rich in uridylate residues. The cytoplasmic species with affinity for poly(A) is similar in size to polyadenylated messenger RNAs and also associates with polysomes. However it appears to be distinct from the polyadenylated messenger RNAs by virtue of an unusual base composition and relative metabolic instability.

Binding Sites↗
PubMed1977

Some problems in the correction for intrinsic light-scattering of samples in specific protein analysis by automated immunoprecipitation.

Heparinised plasma samples have falsely high blank values in the automated immunoprecipitation system when blanks are measured by omitting antiserum from the assay. This is probably due to an interaction of heparin and serum proteins, together with either fibrinogen or polyethylene glycol. A more accurate estimate of the blank of heparinised plasma samples is obtained by measuring it with a solution of nonimmune serum substituted for the antiserum.

Blood↗
PubMed1977

[Complete parenteral nutrition of amino acids, glucose, vitamins and minerals with inclusion of fats].

The objective of complete intravenous nutrition is to supply by the intravenous route all the nutrients normally obtained in the oral diet and the same relative proportions as absorbed from an oral diet. Some suggested allowances to meet these nutritional requirements in patients with different clinical conditions are made. There appears to be little overall difference in the clinical effectiveness of an intravenous regime in which all the non-protein energy is provided by glucose and one in which both glucose and lipid are used. However, the use of a system of complete intravenous nutrition, which by definition must contain lipid, does have specific practical advantages which make it the system of choice in certain circumstances.

Amino Acids↗
PubMed1976

An assessment of the clinical usefulness of plasma ribonuclease assays.

The usefulness of plasma ribonuclease assays was studied in (i) patients with possible protein deficiency, (ii) patients with myelomatosis, (iii) patients with carcinoma of the breast. In each group, the major factor associated with elevation of plasma ribonuclease was impairment of renal function. The assay was therefore of little value in the assessment of patients with myelomatosis or carcinoma of the breast. However, in the patients with possible protein deficiency and normal renal function, an elevation of plasma ribonuclease is, in general, associated with a decrease in serum albumin, transferrin and cholinesterase. Plasma ribonuclease may therefore be a useful parameter in the assessment of protein nutritional status.

Acute Kidney Injury↗