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Biomedical subjects

L A Crane

Publications and source records attributed to L A Crane.

10 recordsLinked to original sources
PubMed1992

Right-side dominance for song control in the zebra finch.

Adult male zebra finches underwent unilateral denervation of the syrinx or unilateral lesion of the forebrain nucleus HVC known to be important for song control. Disruptive effects on song were greater after right-side than after left-side operations. After denervation of the right half of the syrinx, the fundamental frequencies of all syllables within a song converged on a value near 500 Hz, and nearly all syllables were altered in type. In contrast, the syllables produced after denervation of the left side of the syrinx largely maintained their preoperative frequencies, and fewer syllables changed in type. Unlike nerve sections, HVC lesions did not result in strikingly lateralized effects on syllable phonology; however, HVC lesions did affect the temporal patterning of a bird's song, whereas nerve sections did not, and changes in temporal patterning were more marked after right than after left HVC lesions. Right-side dominance for zebra finch song control is the reverse of that described in other songbird species with lateral asymmetry for vocal communication. We suggest that the need for a dominant side is more important than the side of dominance.

Anesthesia↗
PubMed1992

Improving adherence to screening follow-up among women with abnormal Pap smears: results from a large clinic-based trial of three intervention strategies.

In a large randomized trial involving over 2,000 women with abnormal cervical cytology (pap smear), three clinic-based interventions were tested as strategies to increase return rates for screening follow-up: 1) a personalized follow-up letter and pamphlet; 2) a slide-tape program on pap smears; and 3) transportation incentives (bus passes/parking permits). The three interventions were evaluated using a 2 x 2 x 2 factorial design. Results of this study confirm a high rate of loss to screening follow-up (i.e., no return visits) among women with abnormal pap smears (29% overall), with substantial variability among the 12 participating clinics (13% to 42/%). For the sample as a whole, both transportation incentives and the combined intervention condition of personalized follow-up and slide-tape program had a significant positive impact on screening follow-up. However, transportation incentives emerged as the dominant intervention condition among patient subgroups that can be characterized as more disadvantaged socioeconomically and at higher risk of developing cervical cancer, including patients receiving care from the county health department (odds ratio (OR) = 1.51; P less than .05); patients without health insurance (OR = 1.77; P less than .01); and patients with more severe pap smear results (OR = 1.71; P less than .05). In contrast, among patient subgroups that can be characterized as relatively more advantaged and at lower risk of developing cervical cancer, only the combined intervention condition of personalized follow-up and slide-tape program was associated with a higher patient return rate. Subgroups reflecting this pattern included patients seen in noncounty clinics (OR = 4.54; P less than .05) and patients with less severe pap smear results (OR = 5.16; P less than .01). The implications of these findings are discussed in terms of designing clinic-based interventions to improve screening follow-up.

Adolescent↗
PubMed1991

Use of diet pills and amphetamines to lose weight among smoking and nonsmoking high school seniors.

Used data on 3,305 high school seniors collected as part of the 1984 Monitoring the Future project to examine the relationships among cigarette use, diet pill use, and use of amphetamines for weight loss. Results indicate that females were more likely than males to report use of all three substances. In addition, Whites were more likely than Blacks to use all three substances. Both female and male smokers were more likely than nonsmokers to use diet pills. Amphetamine use for weight loss was positively related to smoking among females, but not among males. The relationships between smoking and diet pill use, and smoking and amphetamine use to lose weight, were maintained when race, sex, and other drug use were controlled simultaneously. Two explanations for these relationships are considered. The first is that smoking is related to the use of most other licit and illicit drugs. The second explanation is that there is a greater preoccupation with weight among smokers, with weight concerns potentially motivating the initiation of smoking.

Adolescent↗
PubMed1990

Screening for cervical cancer in emergency centers and sexually transmitted disease clinics.

Low-income women are at increased risk of developing cervical cancer compared with middle- and upper-income women. How can poor women be reached for screening and early diagnosis of cervical cancer and its precursor stages? One answer to this question is based on the observation that a high percentage of the unscreened population has received some form of medical care within the previous 5 years. Emergency centers and sexually transmitted disease (STD) clinics often provide such care to patients who lack a regular source of health care. Thus, they represent potential resources for cervical cancer screening. However, in a survey of 19 hospitals whose patient populations include a high proportion of low-income patients, only five reported a protocol for cervical cancer screening in their emergency centers. Similarly, all 11 STD clinics included in this survey reported that fewer than 5% of their female patients had a Papanicolaou smear taken even though virtually all of them received a pelvic examination. Based on these findings, it appears that health care administrators and policymakers could intensify their cancer prevention programs by mobilizing these resources for cancer control.

Community Health Centers↗
PubMed1979

Simple cannula for repeated intracerebral drug administration in rats.

A simply constructed cannulation system for chronic implantation in rats is described. The guide cannula, stylet and injection cannula are all made from stainless steel tubing, require litte time to construct, and are designed for minimum brain damage and atraumatic infusion into unanesthetized rats.

Animals↗
PubMed1979

Integrated cardiovascular responses to combined somatic and visceral afferent stimulation in newborn piglets.

Mean aortic pressure, arterial flow and heart rate response to interactions of afferent stimulation of the sciatic nerve (SNS) and carotid sinus stimulation by infusion (CSI) or inhibition by bilateral common carotid occlusion (BCCO) were studied in 25 newborn piglets under halothane-N2O anesthesia. Combined stimulation of the somatic and visceral afferents produced no heart rate changes. Combinations of pressor stimuli (BCCO and high frequency SNS) showed facilitation; femoral and renal resistances increased. However, combinations of depressor stimuli (CSI and low frequency SNS) showed occlusion. In combinations of pressor with depressor stimuli, the pressor pattern of responses dominated. Thus, dissimilar types of excitatory afferent inputs are capable of evoking facilitation in the neonatal cardiovascular regulatory system.

Afferent Pathways↗
PubMed1978

Integrated cardiovascular responses to combined somatic afferent stimulation in newborn piglets.

Heart rate, mean aortic pressure and arterial flow responses to interactions of afferent stimulation of the sciatic (SNS) and median nerve of the brachial plexus (BNS) were studied in 30 newborn piglets under halothane-N2O anesthesia. High frequency or intensity SNS or BNS stimulation resulted in pressor responses accompanied by significant increases in the femoral flow and carotid and renal resistance. Combined stimulation produced responses smaller than the estimated sum of the responses. Low frequency or intensity SNS or BNS resulted in depressor responses accompanied by significant decreases in mean femoral flow without change in heart rate; combined stimulation produced responses smaller than the estimated sum. When pressor and depressor patterns of stimulation were combined, pressor responses always dominated. The absence of facilitation to any combination of interactions implies that the cardiovascular regulatory system is not fully developed at birth and undergoes, therefore, postnatal maturation.

Afferent Pathways↗