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Biomedical subjects

D H Baker

Publications and source records attributed to D H Baker.

At least 307 records · Page 17Linked to original sources

Assessment of the quantity of biologically available phosphorus in yeast RNA and single-cell protein.

Two assays were conducted with chicks fed a phosphorus-deficient crystalline amino acid diet from day 8 to 17 posthatching to evaluate the phosphorus availability of purified torula yeast RNA and single-cell protein (Torula yeast). Tibia bone ash of the chicks was the criterion used in both assays, and regression analysis was used to evaluate bone ash as a function of phosphorus intake. A standard curve was established by feeding graded levels of KH2PO4 in each assay. Weight gain, tibia weight and tibia ash all responded to phosphorus supplementation whether provided by KH2PO4, RNA or single-cell protein. Weight of tibia ash provided the best linear fit when evaluated as a function of phosphorus intake. Availability in both assays estimated using the slope-ratio technique wherein milligrams of available phosphorus per gram of RNA or single-cell protein was calculated. In assay 1 the available phosphorus in RNA was found to be 93.2 mg/. In assay 2 the available phorphorus in single-cell protein was found to be 14.1 mg./g.

Animal Feed↗

Radiographic findings in esophageal atresia with proximal pouch fistula (type B).

Patients with esophageal atresia and proximal pouch fistula have plain films that simulate esophageal atresia without fistula. Clinical suspicions of the existence of the proximal pouch fistula may occur when marked aspiration of barium occurs following outlining of the proximal pouch, or by choking spells during irrigation of the proximal pouch. Outlining of the fistula from the pouch requires some form of continuous imaging, either with T.V. tape, cine or 70 mm. spot films. Of interest is the fairly long distal esophageal segment found in the three cases reported, as opposed to the usual short segment of the distal esophagus seen in infants with esophageal atresia without fistula.

Esophageal Atresia↗

Barium enema findings in type I hepatorenal glycogen storage disease.

Four children with Type I hepatorenal glycogen storage have been studied by barium enema. All showed strikingly similar changes of a smooth-walled, slightly narrow but normal length colon without any haustration. The findings simulated colitis but the patients had either mild diarrhea or no gastrointestinal complaints. Small bowel series was normal. Endoscopy and biopsy failed to provide an adequate explanation, there being no evidence of glycogen storage in the biopsy material and the degree of colitis in two patients who were endoscoped was minimal. The explanation for these radiographic findings is not known at present, although they have similarities to the "cathartic colon syndrome" described in adults.

Barium Sulfate↗

Methionine toxicity in the chick: nutritional and metabolic implications.

Several assays with young chicks fed crystalline amino acid diets were conducted to investigate the effects of supplemental glycine, serine, threonine, arginine, or adenine on the growth depression resulting from consumption of excess methionine. Glycine was partially effective in alleviating the growth depression caused by excess methionine. The addition of threonine together with glycine improved performance still further. Efficiency of food utilization for weight gain was greater in birds fed the methionine-imbalanced diet supplemented with glycine and threonine than in those fed the control diet. Supplemental glycine, threonine, or adenine, but not arginine, was effective in ameliorating the hypoglycemia resulting from consumption of excess methionine. The rate of oxidation of a tracer dose of threonine was increased markedly by feeding 1.25% excess methionine. This was reflected in a 20% depression in threonine utilization for weight gain as measured by slope ratio. The data suggest that both threonine and glycine are antagonized by consumption of excess methionine.

Adenine↗

Calcified intraluminal meconium in newborn males with imperforate anus. Enterolithiasis in the newborn.

Five cases are reported and reference is made to 3 previous similar cases of calcified intraluminal meconium in newborn males with "imperforate anus." A rectourinary fistula was found in most of the patients; none of the cases had meconium peritonitis. The calcifications may develop in areas of prolonged stasis; the possible added role of the mixture of urine and meconium in utero is raised.

Abnormalities, Multiple↗

Pancreatitis and the battered child syndrome. Report of 2 cases with skeletal involvement.

Two cases of pancreatitis associated with the trauma of child abuse are reported. In the first case the skeletal survey was initially negative but the child later showed widespread roentgen evidence of intramedullary necrosis and periosteal new bone reaction. These lesions healed without treatment. In the second patient, the pancreatitis was accompanied by ascites and subsequently by bile peritonitis, duodenal obstruction, and a bile-filled abscess in the pancreas. This patient had skeletal fractures. The clinical problems of these 2 patients emphasize the need not only to relate pancreatitis to the battered child syndrome but also to distinguish between the bone changes due to direct trauma and those related to pancreatitis.

Abdominal Injuries↗

The Weissenbacher-Zweymuller syndrome of micrognathia and rhizomelic chondrodysplasia at birth with subsequent normal growth.

Two patients are reported with the clinical and roentgenographic findings of the Weissenbacher-Zweymuller syndrome. The features are neonatal micrognathia (Pierre Robin syndrome), rhizomelic chondrodysplasia with dumbbell shaped femur and humeri. The bone changes tend to regress and there is normal growth on serial studies. A third case seemed at birth to show similar roentgenographic changes but was dwarfed; serial observations revealed him to be a case of the Kniest syndrome with micrognathia as an added feature. The term "micrognathic dwarfism" suggested by Maroteaux is probably best aboided since it will inevitably include a variety of conditions, only some of which are associated with dwarfism.

Diagnosis, Differential↗

Factors associated with utilization of the calcium salt of methionine hydroxy analogue by the young chick.

Six growth assays were conducted using crystalline amino acid diets to investigate the efficacy of methionine hydroxy analogue (OH-M) as a precursor of sulfur bearing amino acids (SAA). The influence on OH-M utilization of dietary modifications of the methionine-cystine ratio, inorganic sulfate as K2SO4 and supplemental mixtures of the branched-chain amino acids (leucine, isoleucine and valine) was explored. Performance of chicks fed OH-M was inferior to those fed an equivalent molar quantity of DL-methionine. Additional dietary sulfate or supplemental mixtures of the branched-chain amino acids did not improve OH-M utilization. OH-M was found to support growth equal to that of 0.35% methionine and 0.35% cystine when fed at a level 25% above the SAA level provided by methionine and cystine. On a weight basis the calcium salt of OH-M has 88.15% OH-M activity. From assays reported herein the calcium salt of OH-M was calculated to have approximately 70% methionine activity.

Amino Acids↗

Lack of response to supplemental tin, vanadium, chromium and nickel when added to a purified crystalline amino acid diet for chicks.

An experiment was conducted to ascertain if supplementing a completely purified diet with tin, vanadium chromium and nickel would enhance chick performance between hatching and 27-days posthatching. No effects on rate and efficiency of gain or on feather development were noted. A level of 350 p.p.m. magnesium, all in inorganic form, was found adequate for chick growth during this period.

Amino Acids↗

Efficacy of D-, L- and DL-methionine for growth of chicks fed crystalline amino acid diets.

Four assays employing young male chicks were conducted to evaluate the relative efficacy of D-, L- and DL-methionine and to estimate the requirement for D- and L-methionine when serving as the sole source of sulfur amino acids or when added to a diet containing 0.27% L-cystine. Crystalline amino acid diets containing 14.9% protein equivalent and 4200 kcal. M.E./kg. were used in all assays. L-methionine supported faster and more efficient gains than D- or L-methionine when fed at levels below thhe requirement. At levels of supplementation near the requirement, however, equal efficacy was attained. When serving as the sole source of sulfur amino acids, the requirement as estimated by least squares for optimal gain was 0.58% of the diet or 104 mg./day for L-methionine and 0.59% or 104 mg./day for D-methionine. In the presence of cystine, the requirements were estimated at 0.27% or 49 mg./day and 0.30% or 52 mg./day for L- and D-methionine respectively. The results indicate that at lower levels of supplementation, L-methionine is a better source of sulfur amino acids than D-methionine. On the other hand, L- and D-methionine appear to have equal efficacy when incorporated into diets that are only marginally deficient in sulfur-bearing amino acids.

Amino Acids↗