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Biomedical subjects

C R Morris

Publications and source records attributed to C R Morris.

13 recordsLinked to original sources
PubMed1989

Hexachlorobenzene episode in Turkey.

During the period 1955-1959, approximately 4000 people in southeast Anatolia developed porphyria due to the ingestion of hexachlorobenzene (HCB), a fungicide added to wheat seedlings. These HCB exposures subsequently led to the development of bullae on sun-exposed areas, hyperpigmentation, hypertrichosis, and porphyrinuria. The condition was called kara yara or "black sore." Many of the breast-fed children under the age of 2 years whose mothers had ingested HCB-treated grain died from a disease known as pembe yara or "pink sore." In this follow-up study of 252 patients, 20-30 years postexposure, there were 162 males and 90 females, with an average current age of 35.7 years, an average of onset of 7.6 years, and a duration of 2.2 years. Many patients had dermatologic, neurologic, and orthopedic symptoms and signs. The observed clinical findings include scarring of the face and hands (83.7%), hyperpigmentation (65%), hypertrichosis (44.8%), pinched facies (40.1%), painless arthritis (70.2%), small hands (66.6%), sensory shading (60.6%), myotonia (37.9%), cogwheeling (41.9%), enlarged thyroid (34.9%), and enlarged liver (4.8%). Urine and stool porphyrin levels were determined in all patients, and 17 have at least one of the porphyrins elevated. A total of 56 specimens of human milk obtained from mothers with porphyria were analyzed for HCB. The average value was 0.51 ppm in HCB-exposed patients compared to 0.07 ppm in unexposed controls. Offspring of mothers with three decades of HCB-induced porphyria appear normal.

Adolescent↗
PubMed1989

Quality assurance in toxicology studies in developing countries.

As developing countries become more involved in the international chemical trade, they must adhere to certain requirements for importation of their chemicals into foreign countries. These developing countries will be required to provide basic safety information on their chemical products, including data developed from chemical and toxicologic testing. These data must be developed in accordance with the national requirements of the importing country. Many importing countries have adopted the OECD Test Guidelines and the OECD Principles of Good Laboratory Practice (GLP) as primary guidance to assure the quality of laboratory data. These procedures provide a basis for internationally acceptable data. Several countries have incorporated many of these provisions into their national laws or administrative procedures. These procedures describe the process of documenting the conduct of laboratory studies, including recording of data, reporting of study results, and storage of data gathered. This process is intended to assure the quality and integrity of the data so that, if required, the study can be reconstructed by an auditor or an inspector. Details of these procedures and their applicability to the international chemical trade are discussed.

Developing Countries↗
PubMed1979

Improvement of pulse-mode photographic images in MDS computer systems.

Users of scintigraphic computer systems manufactured by Medical Data Systems (MDS) frequently experience textured distortion of oscilloscope images when scans are produced by Z-axis modulation. The source of this malfunction has been identified and a way to eliminate the problem is described. The modification is simple and inexpensive. The availability of Z-axis modulation significantly enhances the capabilities of MDS systems.

Computers↗
PubMed1978

The patient's greatest hazard.

To reduce the patient's hazard in the dental office, the dentist must take a medical history, perform a limited medical examination, order and interpret laboratory tests when indicated, initiate medical consultation when necessary, and evaluate the data obtained in order to make appropriate treatment modifications for high risk patients. The current status of health which our population enjoys must not be confused with a status of robustness. An apparently well patient may be in great jeopardy while you are delivering the most skillful dental care unless adequate precautions are taken.

Blood Coagulation Disorders↗
PubMed1977

Antileukemic properties of combinations of radiation and malonato(1,2-diaminocyclohexane) platinum(ii) (NSC-224964).

Mean survival times were increased an average of 23, 53 and 61%, when 10, 15, and 20 mg/kg, respectively, of the organoplatinum congener, malonato(1,2-diaminocyclohexane) platinum(II)(NSC-224964), was given as the only treatment modality to BDF1 mice bearing 1-day-old L1210 leukemia. When a single dose of 10 mg/kg was combined with either 300 or 100 R on day 1 only, the anticipated response (ILS = 30 and 38%, respectively) based on the additive effects of the single modalities was surpassed by 26 and 21%, respectively (i.e. extent of therapeutic synergism). When divided doses of radiation (200 R/day x 3 days) were combined with 15 or 20 mg/kg of NSC-224964, survival times were enhanced an average of 15% (extent of synergism) greater than would be expected if these modalities were acting through an additive process(es).

Animals↗
PubMed1976

The effects of single administration of an antitumor platinum compound on ornithine decarboxylase activity in certain tissues of mice bearing L1210 leukemia.

A single dose of cis-dichloro(dipyridine)platinum(II) (cis-PPC), when given to BDF1 mice bearing 1-day-old L1210 leukemia, suppressed the increase of spleen and liver ornithine decarboxylase (ODC) activity which occurs concomitantly with development of the leukemia. The inhibition of ODC, the rate-limiting enzyme in polyamine synthesis, appeared to correlate with the prolonged chemotherapeutic efficacy of a single dose of the platinum complex. These observations suggest an additional mechanism by which platinum complexes express their antitumor actions and, in addition, support the view that polyamine synthesis and excretion patterns can be used as predictors of chemotherapeutic response.

Animals↗