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Biomedical subjects

D A Roth

Publications and source records attributed to D A Roth.

90 records · Page 5Linked to original sources
PubMed1979

Low temperature induces decreased germinability of Cylindrocladium microsclerotia.

Numbers of germinable Cylindrocladium crotalariae microsclerotia (assayed at 26 degrees C) decreased progressively over 4 weeks when naturally infested soils were incubated at 6 degrees C. Lower numbers of germinable microsclerotia were obtained from a soil incubated at--3 than at 5 degrees C, while no germinable microsclerotia were found for soils incubated at--10 degrees C. Significantly, when soils incubated at--10 or at 6 degrees C for 4 weeks were transferred to 26 degrees C for 4 weeks, the low-temperature effect was partially reversed. Incubation of naturally infested soils under field conditions from October to February indicated that a similar low-temperature induced phenomenon exists in nature. Germinability of axenic laboratory-grown microsclerotia of C. crotalariae, C. floridanum, and C. scoparium incubated 4 weeks at 6 degrees C ranged from 0 to 91% (mean = 38%) of the initial germinability. Partial recovery of laboratory-grown microsclerotia from the low-temperature effect, by incubation at 26 degrees C, was demonstrated. Conductivity measurements of solutions bathing microsclerotia incubated at 6 degrees C were higher than those incubated at 26 degrees C for 4 weeks and indicated that chilling injury may account, in part, for decreased germinability of microsclerotia.

Cold Temperature↗
PubMed1977

Renal proximal tubular dysfunction and paroxysmal nocturnal hemoglobinuria.

A patient with paroxysmal nocturnal hemoglobinuria, who required many blood transfusions for hemolytic episodes, had a persistent hyperchloremic metabolic acidosis. Bicarbonate infusion demonstrated a large fractional excretion of bicarbonate (28.6 per cent at a plasma bicarbonate level of 23 meq/liter) which was consistent with proximal renal tubular acidosis. Generalized aminoaciduria and decreased tubular reabsorption of phosphate were also present. Marked deposition of iron in renal proximal tubules was associated with these functional abnormalities. We believe that, as systemic acidosis can promote hemolysis in patients with paroxysmal nocturnal hemoglobinuria, hemolysis can lead, by way of iron deposition in renal tubules, to further acidosis. This cycle should be interrupted with appropriate doses of bicarbonate.

Acidosis, Renal Tubular↗
PubMed1977

High-performance liquid chromatography of pyruvic and alpha-ketoglutaric acids and its application to urine samples.

Pyruvic and alpha-ketoglutaric acids were quantitatively and rapidly converted to quinoxalones by a new method, to enhance their detectability in the ultraviolet. The quinoxalones were separated by reversed-phase chromatography with use of 10 micronm particles packed in a 30-cm (length) column. An aqueous solution of ammonium acetate and methanol was used for linear gradient elution. The urinary excretion of pyruvic and alpha-ketoglutaric acids by normal individuals, diabetic patients, and patients with renal dysfunction was determined.

Chromatography, High Pressure Liquid↗
PubMed1976

Cervical analgesic discography. A new test for the definitive diagnosis of the painful-disk syndrome.

The cervical discogenic (painful-disk) syndrome consists of scapular pain radiating into the head, shoulder, and upper arm, often associated with paresthesias but without neurologic deficit. Plain roentgenograms or myelograms are normal or show degenerative changes. Positive-contrast discography has been useful but is subject to a high percentage of false-positive results roentgenographically and nonspecific pain patterns clinically. Analgesic discography more precisely confirms the diagnosis and more accurately locates the pain-producing disk. Injection of a local anesthetic into a painful disk produces transient symptomatic relief and full neck mobility. Its use during a two-year period in 71 consecutive discogenic patients followed by anterior cervical fusion resulted in a 93% excellent or good recovery rate. Analgesic discography is the most effective test for diagnosis and location in the painful-disk syndrome.

Analgesia↗
PubMed1975

Disseminated MYycobacterium kansasii infection with pancytopenia and interstitial nephritis.

Disseminated Mycobacterium kansasii infection associated with pancytopenia was diagnosed in a 40-year-old man found to have granulomata in kidney and liver biopsy specimens. The M. kansasii was isolated from the urine and tissue obtained by renal biopsy. Serial renal biopsies and renal tissue obtained at autopsy showed severe interstitial fibrosis which was thought to represent a tissue response to the M. kansasii infection. The periportal and parenchymal fibrosis found in the liver at autopsy were consistent with a similar response in the liver.

Adult↗
PubMed1971

Prognosis of pituitary adenomas with arteriographic abnormal vascularization.

A case report and five additional cases from the literature of angiographically demonstrated abnormal vascularization of chromophobe adenomas are presented. The appearance is that of a fine network of vessels appearing in the arterial phase and a homogeneous blush beginning in the capillary phase and lasting throughout the venous phase. The network is derived from dilated branches of the extradural internal carotid artery and is seen in the arterial phase. The stain, appearing in the venous phase, is due to filling of tiny sinusoidal channels and thin-walled vessels throughout the stroma. All the patients had large, actively growing tumours which compressed and infiltrated surrounding structures. Complete tumour removal was not possible in the patients operated upon. The combined morbidity-mortality rate was 83% and was due to the large tumour size, adherence to vital centres, extreme vascularity during surgical removal, and propensity to bleed spontaneously. The appearance of abnormal vascularity in a pituitary adenoma suggests a poor prognosis.

Adenoma, Chromophobe↗