Biomedical subjects

A C Klassen

Publications and source records attributed to A C Klassen.

42 records · Page 3Linked to original sources

PubMedDate not supplied

Cerebrospinal fluid in cerebral hemorrhage and infarction.

Cerebrospinal fluid (CSF) abnormalities were correlated with pathological diagnoses in 61 patients with autopsy-verified intracerebral hemorrhage or cerebral infarction. Lumbar punctures were performed within one week of onset of symptoms. The CSF color and red blood cell counts were the most useful CSF parameters in differentiating between intracerebral hemorrhage and cerebral infarction. In 75% of the patients with intracerebral hemorrhage, the CSF was either grossly bloody or xanthochromic; in 25%, the CSF was clear. In patients with cerebral infarction, the CSF was never grossly bloody; in two patients with hemorrhagic infarction, the CSF was xanthochromic. The CSF pressure, protein values and leukocyte counts were less useful in differentiating intracerebral hemorrhage from cerebral infarction. Cases with hemorrhagic infarction could not be separated from those with ischemic infarction on the basis of CSF analysis. In clear CSF, the polymorphonuclear neutrophilic leukocyte (PNL) counts were never greater than 20 per cubic millimeter. In xanthochromic or cloudy CSF, leukocyte counts, especially PNLs, were frequently elevated, occasionally to the high levels.

Cerebral Cortex↗

PubMedDate not supplied

Respiratory rate and pattern disturbances in acute brain stem infarction.

Respiratory rates and patterns were studied in 23 patients with acute brain stem infarction using impedance pneumography. Autopsy was obtained in six of eight fatal cases. Pontine lesions were present in all patients, with coexistent infarction of midbrain in four and of medulla in nine. Respiratory rate and pattern abnormalities observed included Cheyne-Stokes respiration, Cheynb-Stokes variant pattern and tachypnea. Abnormalities of respiratory rate and pattern of varying duration were observed at some time in all patients. All patients in whom prominent Cheyne-Stokes respiration or tachypnea were observed had extensive bilateral pontine lesions involving both basal and tegmental portions. However, not all patients with large pontine infarcts had Cheyne-Stokes respiration or tachypnea. Cheyne-Stokes respiration was prominent in four patients (two fatal, two nonfatal). Cheyne-Stokes variant pattern was present frequently in four patients (one fatal, three nonfatal). Sustained tachypnea developed in five patients, four of whom died. In ten patients (one fatal, nine nonfatal), normal respiratory rate and pattern predominated with only rare or occasional apperance of Cheyne-Stokes respiration or Cheyne-Stokes variant pattern, especially during sleep. The types of respiratory rate and pattern abnormalities in acute brain stem infarction were not specifically related to the level of lesions, but rather to the size and bilaterality of the lesions. Respiratory alkalosis was present in varying degrees in most patients with either tachypnea or prominent CSR.

Acute Disease↗

PubMedDate not supplied

Sympathetic regulation of cephalic blood flow.

Blood flow to bilateral tissues (cranial and extracranial) was studied by means of the particle distribution method in two groups of anesthetized dogs (five using 25-mu radioactive microspheres, six using 15-mu microspheres) and five anesthetized stumptail Macaques monkeys (8-mj spheres) during unilateral sympathetic stimulation. The stimulatory parameters were adjusted to produce maximum pupillary dilatation. In the five dogs hemispheric and regional cerebral blood flow decreased but not significantly. Flow to the extracranial tissues decreased 82%. Hemispheric brain blood flow averaged 0.70 ml/min/gm for Paco2 of 40 mm Hg. In the six dogs sympathetic stimulation did not significantly decrease cerebral blood flow but decreased flow to extracranial tissues (72.3%). At an average Paco2 of 33.2 mm Hg, hemispheric blood flow to the unstimulated side averaged 0.51 ml/min/gm. In the five monkeys findings were essentially the same as those observed in the dogs. The hemispheric blood flow averaged 0.36 ml/min/gm on the nonstimulated side for an average Paco2 of 36.6 mm Hg. Under the conditions studied, electrical stimulation of the cervical sympathetic nerves does not appear to modify regional or total brain blood flow in dogs and Macaques monkeys. The vascular response in oral and other extracranial tissues is very dramatic, however.

Animals↗

PubMedDate not supplied

Cancer screening services for the elderly.

The reported practices and recommendations of primary care physicians with regard to cancer screening of elderly patients (65 years and older) were studied in a 1987 survey of 400 Maryland physicians. More than 90 percent of physicians in four specialties studied reported providing digital rectal examinations, physical breast examinations, and mammography to the elderly. However, only 54 percent of obstetrician-gynecologists and 68 percent of general practitioners provided sigmoidoscopy, 70 percent of obstetrician-gynecologists provided stool guaiac slide tests, 74 percent of general practitioners provided breast self-exam instruction, and 79 percent of internists provided Pap tests. Physicians were asked what screening intervals they recommended for each test for asymptomatic elderly patients. These reports were compared with current American Cancer Society (ACS) recommendations. Large proportions of physicians in four specialties recommended sigmoidoscopy and mammography less often than the ACS recommended. More than 20 percent of physicians in the four specialties believed the elderly do not need routine sigmoidoscopy. Most physicians (90 percent or more) recommended Papanicolaou tests more often than the ACS recommended. Specialty and young physician age were the best predictors of physicians' overall adherence to ACS recommendations for cancer screening schedules.

Aged↗

PubMedDate not supplied

Curtailment of well child services by a local health department: impact on rural 2-year-olds.

The impact of changes in the delivery of well child health services by a rural health department on the reported health status, immunization status, and patterns of health care use is evaluated for poor children born in 1981, when well child clinic services were reduced. Using birth certificate records, all 1981 resident births were enumerated for the case county in Maryland and for a demographically similar comparison county that had continued to operate health department well child clinics. Trained local interviewers tracked and interviewed mothers or guardians of the 1981 cohort. Data were obtained on 567 of 589 eligible children, reflecting a 96 percent response rate. Children in each county were defined as poor if their mothers reported receiving AFDC (Aid to Families with Dependent Children), food stamps, or medical assistance or reported annual household incomes of below +5,000. This poverty status indicator was significantly correlated with health department use in the comparison county. Findings indicate that mothers of poor children in both counties were as likely as mothers of nonpoor children to assess their 2-year-old's health status as good, to identify a regular source of preventive care, and to report complete immunizations for their toddler. Although many private physicians in the case county appear to be seeing poor children in their offices, the distribution of study children among physicians was highly skewed. Out of 19 physicians or health facilities in the case county, one pediatrician was reported as the primary source of pediatric care for 52 percent of the 2-year-olds, one-third of whom were poor. In contrast, no one physician or facility was reported as providing pediatric care for more than 10 percent of 2-year-olds in the comparison county. Findings are discussed in light of these differences in physician supply and practice patterns.

Child Health Services↗

PubMedDate not supplied

Drug use and illnesses among eighth grade students in rural schools.

We examined the relationship between drug use by young adolescents and two indicators of illness, frequency of illness and numbers of days absent from school owing to illness. Data were from a general health survey of all eighth grade students enrolled in public schools in two rural Maryland counties. A total of 745 students completed a self-administered questionnaire during school hours in January 1984. Information was obtained on a variety of sociodemographic characteristics and on the students' use of tobacco, alcohol, and marijuana. Correlational analyses were used to examine the relationships among cigarette smoking, beer or wine drinking, whiskey or hard liquor drinking, and marijuana use. Logistic regression was used to model the effects of drug use behaviors on the likelihood of being absent from school 3 or more days, adjusting for the student's age, sex, race, parents' education, illness frequency, and concerns about learning problems in school. We found substantial covariation among the use of cigarettes, alcohol, and marijuana. After adjusting for the background variables of illness, frequency, and learning problems, we found that students who are frequent cigarette smokers experienced a 2.6 risk of school absenteeism. Other drug use behaviors were not associated significantly with increased risk of missing school. Findings are discussed within the context of health-related consequences of drug use.

Absenteeism↗