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Biomedical subjects

S Marks

Publications and source records attributed to S Marks.

At least 37 records · Page 2Linked to original sources
PubMed1997

Evaluation of an educational program to prevent adolescent pregnancy.

The authors evaluated the effectiveness of a school-based sex education program in decreasing rates of sexual intercourse, improving birth control use, and decreasing the incidence of pregnancies among teenagers 16 years of age and younger. Twenty-one schools received either the McMaster Teen Program or the conventional didactic sex education program. Preprogram, the mean age of the students was 12.6 years. There were no statistically significant differences between groups in time to first sexual activity for males, chi 2(1) = 2.93, p = 0.09; time to first sexual activity for females, chi 2(1) = 0.50, p = 0.48; and time to first pregnancy, chi 2(1) = 1.90, p = 0.17. Significantly more experimental group males reported always using birth control at year 1 (difference 8.9%; 95% confidence interval [CI] = 0.4, 17.4). Limitations of the program that may have influenced the results were the exclusion of contraception information and its short duration.

Adolescent↗
PubMed1997

South Africa's early experiment in social medicine: its pioneers and politics.

The election of a democratic, nonracial government in South Africa has moved the health needs of the majority of the population to center stage. In the search for precedents, health policymakers have turned to South Africa's pioneering of health centers and social medicine in the 1940s. This paper looks at the intellectual context in which these ideas were first developed; the particular political circumstances and relationships between doctors and the state in the late 1930s, which facilitated the establishment of health centers; the role that the health centers were intended to play in South Africa's wider postwar health plans; and the reasons for the centers' failure. Contrary to conventional wisdom, it argues that the failure of the health centers and the wider health plans predated the advent of the National Party to power in 1948, and resulted mainly from the marginalization of the centers as a low-cost option for the poor, which was itself a consequence of underfunding and the vested interests of local health authorities and private practitioners.

History, 20th Century↗
PubMed1997

Comparing the subjective, psychomotor and physiological effects of intravenous nalbuphine and morphine in healthy volunteers.

The purposes of this study were to characterize the subjective, psychomotor and physiological effects of nalbuphine in healthy non-drug abusing volunteers and to compare and contrast the effects of equianalgesic doses of nalbuphine and morphine. Subjects (12 males, 4 females) without histories of opiate dependence were injected in an upper extremity vein with 0, 2.5, 5.0 or 10 mg/70 kg nalbuphine, or with 10 mg/70 kg morphine, using a randomized, double-blind, crossover design. The 10-mg doses of nalbuphine and morphine are considered equianalgesic and are doses commonly given for relief of postoperative pain. Subjective effects of nalbuphine included increased scores on the Pentobarbital-Chlorpromazine-Alcohol Group scale and the Lysergic Acid Diethylamide scale of the Addiction Research Center Inventory; increased adjective checklist ratings of "nodding," "numb" and "sweating"; increased visual analog scale ratings of "coasting or spaced out," "high" and "sleepy" and increased "feel drug effect" and drug-liking ratings. Ten milligrams of nalbuphine had subjective effects similar, and similar in magnitude, to those of 10 mg of morphine. Nalbuphine produced exophoria and impairment on the Digit Symbol Substitution Test in a dose-related fashion. Ten milligrams of morphine produced exophoria but did not affect performance on the Digit Symbol Substitution Test. Both nalbuphine and morphine induced miosis and decreases in respiration rate. The results of the present study demonstrate that 2.5 to 10 mg nalbuphine had orderly, dose-related effects on subjective, psychomotor and physiological variables. The results also indicate that 10 mg of nalbuphine produces a profile of subjective, psychomotor and physiological effects similar to that of an equianalgesic dose of morphine (10 mg). The similarity in profiles between drugs at this dose is consistent with both infrahuman studies, which suggests that nalbuphine is a mu agonist, and studies with nondependent opioid abusers, in which relatively low doses of nalbuphine (such as 10 mg) produce morphine-like effects.

Adult↗
PubMed1997

Strategies to protect bone mass in the older patient with epilepsy.

The annual incidence of epileptic seizures rises dramatically after the age of 60. Risk factors associated with late-onset epilepsy include cerebrovascular disease, dementia, infection, trauma, and alcoholism. The dominant cause of seizures in older patients is a previous stroke, whereas a significant percentage of cases are attributed to the presence of a tumor. Normal aging is associated with an increased risk for fractures from trauma and osteoporosis. Antiepileptic medications may exacerbate this problem by adversely affecting bone metabolism and increasing the risk of falls related to drug toxicity. The patient work-up, careful prescribing, and monitoring for drug toxicity can help preserve bone integrity in patients receiving antiepileptic drug therapy.

Age Factors↗
PubMed1996

The effects of a cold-water immersion stressor on the reinforcing and subjective effects of fentanyl in healthy volunteers.

The reinforcing and subjective effects of fentanyl, an opioid analgesic, were tested in ten healthy volunteers without histories of drug abuse, as a function of the temperature of a water bath in which the volunteers' forearms were immersed. The temperatures were body-temperature (37 degrees C), moderately cold (10 degrees C), and very cold (2 degrees C). A discrete-trial choice procedure was used in which, in each session, volunteers sampled 50 micrograms of fentanyl (delivered as a bolus via an infusion pump) and saline, and then on three successive trials, chose between the two. Volunteers then had to immerse their non-dominant forearm in the water bath 5 min after a drug delivery. Fentanyl was chosen on 77% of choice occasions in the 10 degrees C and 2 degrees C water conditions, which was significantly different from chance levels, and on 60% of choice occasions in the 37 degrees C water condition, which did not differ from chance levels. Several subjective effects of fentanyl were also modulated by the temperature of the water bath. We conclude that in the context of a painful stimulus, 50 micrograms of fentanyl functions as a reinforcer in non-drug abusers.

Adult↗
PubMed1996

The reinforcing effects of brief exposures to nitrous oxide in healthy volunteers.

The reinforcing and subjective effects of brief (about 1.5 min) exposures to nitrous oxide, ranging from inspired concentrations of 20-80% in oxygen, were examined in 11 healthy volunteers. A choice procedure was used in which during each of four sessions, subjects first sampled a given concentration of nitrous oxide and placebo oxygen, and then chose between the two. 20, 40, 60 and 80% nitrous oxide were chosen by five, four, three, and three subjects, respectively--these choice levels did not exceed that of chance. All concentrations had psychoactive effects, and in general, concentration-related subjective effects were found. We conclude that in a medical setting, nitrous oxide inhaled in a manner similar to that when used recreationally in a naturalistic setting, does not function as a reinforcer across a wide range of concentrations, in subjects with a modest lifetime history of psychoactive drug use.

Adult↗
PubMed1996

Submucous cleft palate: diagnostic methods and outcomes of surgical treatment.

The following statements summarize our interpretation of the literature regarding submucous cleft palate: Incidence and Diagnosis of Submucous Cleft Palate 1. In surveys of classic stigmata of submucous cleft palate among the general population, the incidence has been reported to be 0.02 to 0.08 percent. In the larger of these series, the incidence of velopharyngeal inadequacy among patients identified to have submucous cleft palate was 1 to 9. The incidence of occult submucous cleft palate is not known, since these patients will only be detected during the evaluation of patients who present with velopharyngeal inadequacy. 2. The diagnosis of submucous cleft palate is made by identification of the classic stigmata on physical examination. The diagnosis of occult submucous cleft palate is only pursued if the patient has velopharyngeal inadequacy. 3. For consistency in evaluating and reporting data, patients with an overt cleft of the secondary palate that extends beyond the uvula should be reported as having a cleft palate, and not a submucous cleft palate, even if a submucous cleft exists in a portion of the palate anterior to the overt cleft. 4. The true incidence of otitis media with effusion in the presence of submucous cleft palate has yet to be determined using a prospective study. Surgical Treatment of Velopharyngeal Inadequacy in Patients with Submucous Cleft Palate 1. The technique that has most consistently been documented to result in a significant correction of velopharyngeal inadequacy is the pharyngeal flap. There is recent evidence from one large center supporting the efficacy of the Furlow Z-plasty in selected patients with submucous cleft palate. Both these procedures appear to be most effective in patients with good lateral pharyngeal wall motion. 2. If a pharyngeal flap is performed as the primary procedure to act as an obturator against which the lateral pharyngeal walls appose for closure, we do not see the need for adjunctive palatal procedures. The dynamic component of velopharyngeal competence following such a pharyngeal flap consists of lateral wall motion, which is not enhanced by further surgical manipulation of the palate. However, a pharyngeal flap may be performed as an adjunctive procedure to a palatal pushback in order to provide lining for the resultant defect in the nasal mucosa. 3. The present literature does not support "prophylactic" operations on patients who present with the physical stigmata of submucous cleft palate prior to reaching an age at which it can be demonstrated by perceptual speech assessment that velopharyngeal inadequacy remained refractory to speech therapy. A significant number of patients will never develop velopharyngeal inadequacy; therefore, surgery would be unnecessary. In addition, objective data regarding the outcomes of different surgical techniques cannot be gathered if patients with submucous cleft palate are operated on without having had velopharyngeal inadequacy documented prior to those operations. 4. In order to objectively compare the outcomes of different surgical techniques, any future studies should be prospective and utilize uniform means of assessment. As minimum criteria, these would include preoperative and postoperative perceptual speech assessments performed by a trained speech pathologist and preoperative nasopharyngoscopy and multiview videofluoroscopy. The latter two studies should be repeated postoperatively only in those patients who have persistent velopharyngeal inadequacy.

Age Factors↗
PubMed1995

HIV risk status and preventive behaviors among 17,619 women.

OBJECTIVES: To document the percentage of women at high risk for human immunodeficiency virus (HIV) infection among primary care clients, identify their most prevalent risk factors for HIV infection, and examine the relationships between risk status and preventive behaviors for HIV infection. DESIGN: Cross-sectional. SETTING: Urban and nonurban primary care clinics. PARTICIPANTS: Female clients (N = 17,619) who voluntarily completed an HIV risk-assessment form. MAIN OUTCOME MEASURES: HIV risk status, condom use, and previous HIV testing. RESULTS: Using criteria from the Centers for Disease Control, the study found 14% of the sample to be at high risk for HIV infection. Prevalent risk factors were having sex with persons at high risk for AIDS, having sex with more than six persons in a year, and having more than two sexually transmitted diseases. Women at high risk were more likely to be older, urban, and black. Overall, rates of consistent condom use and HIV testing were low, 12% and 7%, respectively. Older women, coupled women, and women of color were least likely to use condoms consistently. Women at low risk were less likely to have had HIV tests. CONCLUSIONS: To prevent HIV infection, nursing interventions can target women of all ages, especially urban and black women. Nurses should use strategies and skills to promote condom use that are different from those they use to encourage HIV testing.

AIDS Serodiagnosis↗
PubMed1995

Stress velopharyngeal incompetence in an adolescent trumpet player.

The youngest reported patient with stress velopharyngeal incompetence is presented. The patient's symptoms responded to rest with a possible contribution from palatal exercise. Surgical correction would appear to best be reserved for the professional musician with this unusual condition.

Adolescent↗
PubMed1995

The endoscopic management of sphenoid and ethmoid mucoceles with orbital and intranasal extension.

Mucoceles of the sphenoidal and ethmoidal sinuses act as benign neoplasms and can result in bony erosion extending from within the confines of the sinuses into the intracranial and orbital spaces. Endoscopic management of such mucoceles has been debated, and, by some, considered a radical form of therapy. A review of consecutive patients with sinus mucoceles revealed eight sphenoid and six ethmoid mucoceles. Four of these were confined to the sinuses and 11 extended outside of the confines of the sinuses. There were four with intracranial extension, two with orbital extension, three with both intracranial and orbital extension, and two involving the clivus. All 15 patients were managed with endoscopic decompression. Two patients with ethmoid-frontal mucoceles also had frontal sinus obliteration, via an osteoplastic flap along with sphenoethmoidal decompression with an endoscopic approach. Thirteen patients had more than one year of follow-up. Two patients with ethmoid mucoceles with intracranial extension had recurrences of the mucoceles which again have been decompressed endoscopically. There were no orbital or intracranial complications in relationship to these procedures or from the mucoceles. Symptoms related to the mucoceles including loss of vision and severe headaches were resolved with decompression. The endoscopic management of sphenoid and ethmoid mucoceles with orbital and intracranial extension is a safe and reliable approach, obviates the need for major intracranial surgery and diminishes post-operative morbidity. Close follow-up is necessary and secondary decompression can be accomplished should the mucocele recur.

Endoscopy↗
PubMed1994

Economic losses caused by foodborne parasitic diseases.

Fragmentary data indicate that zoonotic parasites cause human illnesses with medical costs and productivity and disability losses totalling billions of dollars annually. Food is an important vehicle for some of these parasitic diseases. The cost to public health is not reflected in the priorities given to these parasitic diseases in either research or public health planning. In this article, Tanya Roberts, Darwin Murrell and Suzanne Marks discuss the cost of toxoplasmosis, taeniasis, cysticercosis, trichinellosis and other foodborne parasitic diseases.

Journal Article↗
PubMed1991

Ultrasound attenuation of the calcaneus: a sensitive and specific discriminator of osteopenia in postmenopausal women.

Recent studies have evaluated techniques for estimating bone mass without radiation. The present study compares broadband ultrasound attenuation of the calcaneus and bone densities of the femoral neck and the lumbar spine in 17 normal women and 41 women with osteoporosis. Twenty of the osteoporotic women had spine (n = 16) or femoral neck (n = 4) fractures. There was a significant decrease in the broadband ultrasound attenuation (P less than 0.001) in women with osteoporosis compared with normal women. The osteoporotic women also showed a decrease in vertebral (P less than 0.0001) and femoral neck (P less than 0.0001) densities compared with normal women. At 63 dB/MHz, the sensitivity and specificity of broadband ultrasound attenuation for decreased bone mineral density with or without fractures were 76%. All women with fractures had a broadband ultrasound attenuation less than 72 dB/MHz. This corresponded to a specificity of 41%. To determine whether broadband ultrasound attenuation correlated with trabecular bone volume, samples of cadaver calcaneus were analyzed. The histologic determination showed a significant correlation between broadband ultrasound attenuation and trabecular bone volume (r = 0.992, P = 0.008). These results suggest broadband ultrasound attenuation of the calcaneus reflects bone mass and can be used as a safe and sensitive indicator for decreased axial bone density.

Absorptiometry, Photon↗