Ethosuximide kinetics: possible interaction with valproic acid

Ethosuximide kinetics were determined in six normal healthy adults after a single dose (phase 1) and at steady-state (phase 2). After the completion of phase 2, valproic acid was added to the ethosuximide regimen (phase 3) to assess the possibility of drug interaction. Between phases 1 and 2 total clearance fell from 13.1 to 11.1 ml/hr/kg (P less than 0.05) and nonrenal clearance fell from 10.1 to 8.3 ml/hr/kg (P less than 0.05). When valproic acid was added (phase 3) there was no further change in total or nonrenal clearance (11.2 and 8.3 ml/hr/kg). To assess the possibility of nonlinear ethosuximide kinetics a review was conducted of patients who received ethosuximide as sole therapy for absence seizures. Of 106 patients, 10 met the required criterion that defined steady state. Data from seven of the 10 patients showed evidence of a nonlinear relationship when steady-state ethosuximide concentrations were plotted against dose.

A conceptual model for determining the least restrictive treatment-training modality

Much attention has been paid in recent years to the concept of the least restrictive treatment or training for developmentally disabled individuals. However, few well-defined procedures exist for determining the restrictiveness of modalities commonly used with these individuals. The authors identified ten frequently used modalities and six criteria for determining their relative restrictiveness. A total of 97 mental health professionals rated each modality according to the criteria, and a generalized rank order of the ten was obtained. Criteria were then established for applying the more restrictive modalities to individual residents' cases. The authors propose a four-part review process to ensure that the individual needs and rights of residents are respected.

An open comparison of dosage frequencies of beclomethasone dipropionate in seasonal allergic rhinitis

In an open group-comparative study, 123 adult patients with seasonal allergic rhinitis were allocated at random to one of three treatment groups; each of which received a daily dose of 400 micrograms beclomethasone dipropionate as (1) one puff in each nostril four times daily, (2) two puffs in each nostril twice daily and (3) four puffs in each nostril once per day. The result of treatment was assessed on daily symptom scores and the use of antihistamine tablets. There were no statistically significant differences between the three groups. The results indicate that it is unnecessary to give beclomethasone dipropionate nasal spray four times daily, and treatment in the morning and in the evening is recommended.

Injuries to the upper extremity: patterns of occurrence

Injuries to the upper extremity, as reported in home interviews, physician office records, and hospital records, are a problem of great magnitude. Upper extremity injuries not only are responsible for a great deal of disability and for a large number of visits for medical care, but also, because they often affect people of working age, have a great impact on society because of loss of productivity. However, regardless of the age at which they occur, these injuries can have an impact on the quality of life of the injured, both in the short term and in the long.

Binding of fibronectin to Clq; inhibition of binding by aggregated IgG

Fibronectin was shown to bind to C1q using alkaline phosphatase conjugated fibronectin and C1q coated polystyrene tubes. The binding of the alkaline phosphatase conjugated fibronectin to C1q was dose dependent and inhibited by fibronectin and by the sulfated polymers heparin and chondroitin sulfate. The fibronectin interaction was inhibited only slightly by gelatin indicating that the fibronectin-gelatin interaction was different from that with C1q. Heat aggregated IgG blocked the binding of fibronectin to C1q and fibronectin inhibited the binding of aggregated IgG to C1q. These results suggest that fibronectin may be a factor affecting the determination of immune complexes in serum specimens by C1q binding assays.

Infrared spectrometer for Voyager

The Voyager IR investigation uses a Michelson interferometer with a 4.3-cm(-1) spectral resolution in the 80-2500-cm(-1) range and a single-channel radiometer for the visible and near-IR, 5000-30,000-cm(-1). Both devices share a Cassegrain telescope with a 50-cm diam primary mirror and a 0.25 degrees field of view. Design, calibration, and performance are discussed along with a sample spectrum of Jupiter.

Attitudes and choice of contraceptive

Attitudes towards contraceptive methods were sampled among 117 women, in their mid-20's, selecting a new method (Pill, IUD, Injectable) and a comparison group of women undergoing termination of pregnancy for the first time. High concordance was found, suggesting women were applying essentially the same standards in making their selection.

Acute microwave irradiation and cataract formation in rabbits and monkeys

Rabbits and monkeys were irradiated in the near field of a cavity-backed 2450 MHz resonant slot radiator, to determine the cataractogenic threshold. Rabbits developed cataracts at incident "apparent" power densities of 180 mW/cm2 (E2/120 pi, where E=rms/electric field strength). Monkeys sustained facial burns, but no lens damage, even at incident "apparent" power densities of 500 mW/cm2. These results were substantiated by computer thermal models.

Antenatal diagnosis in practice

Over a period of 5 years, 434 women at risk of having abnormal babies have had antenatal daignostic tests carried out during the first half of their pregnancy by the laboratories of the Department of Human Genetics, University of Cape Town. From these investigations, it was predicted that 13 fetuses had chromosomal abnormalities, 6 had severe central nervous system defects and 4 had autosomal recessive metabolic disorders. In addition, 4 cases with X-linked recessive traits were monitored and 3 male fetuses were recognized. Affected pregnancies were terminated except for 1 with a fetal sex-linked disorder where the parents revoked their original decision. The diagnosis was confirmed by fetal autopsies in all cases except 4 (2 spontaneous abortions and 2 out-of-town terminations). There was only 1 case where culture failed and the pregnancy went to term with the birth of a baby with Down syndrome. Antenatal diagnosis is now an important part of normal clinical practice. The fact that the fetal abnormalities were recognized in 6% of pregnancies is justification for the use of this procedure.

Experimental pancreatic carcinogenesis. II. Lifetime carcinogenesis studies in the outbred Syrian golden hamster with N-nitroso-bis(2-hydroxypropyl)amine

A high incidence of pancreatic duct neoplasms was induced in outbred male Syrian golden hamsters following weekly sc injection of N-nitroso-bis(2-hydroxypropyl)amine for life. The first such tumors appeared as early as 16 experimental weeks; the maximum incidence reached 100% by the termination of the study. Tumors in the respiratory tracts and angiosarcomas of the livers of the hamsters were also observed in high frequency. Latency of the induced neoplasms was significantly decreased by the substitution of distilled water for olive oil as the vehicle for the carcinogen.

Diagnosis of occult familial medullary carcinoma of the thyroid using pentagastrin

Medullary carcinoma of the thyroid is unique in that it can often be diagnosed solely on the basis of abnormally high basal serum thyrocalcitonin levels. Two brothers described in this report were found to have normal basal serum thyrocalcitonin levels when examined after another family member died from metastatic medullary carcinoma of the thyroid. Pentagastrin, a synthetic analog of gastrin, was subsequently administered to these two high-risk relatives and found to stimulate the release of thyrocalcitonin to abnormally high levels. They were found to have occult medullary carcinoma of the thyroid. Eight other first-degree relatives of the deceased patient with normal basal serum thyrocalcitonin levels were screened with pentagastrin and found to have normal stimulated levels of thyrocalcitonin. This report reinforces the need to recognize that medullary carcinoma of the thyroid can be familial and that physicians are obligated to screen asymptomatic kin who are at high risk. We recommend that all susceptible relatives, even if they have normal basal serum thyrocalcitonin levels, undergo the provocative pentagastrin test with repeat annual testing if necessary. In addition, the provocative pentagastrin test can be used to follow up patients who have undergone thyroidectomy.

Labetalol in the difficult hypertensive patient in general practice

An open study was carried out in general practice to assess the effectiveness and tolerance of labetalol in the treatment of 53 difficult hypertensive patients, most of whom had failed to respond to previous hypotensive therapy. The results showed that in the 49 patients receiving treatment for more than 3 months good blood pressure control was readily achieved, and with labetalol alone in all but 6 of them. The majority were controlled on doses ranging from 300 to 600 mg per day. Treatment was discontinued in 3 patients because of severe side-effects. Mild, tolerable side-effects, similar to those found with beta-adrenergic blocking agents, were reported by 35 patients.

Patterns of second malignant neoplasms in children

A search of the records of 10 pediatric oncology centers revealed 102 children with more than one malignant neoplasm. In this group of 102 patients, all pediatric cancers were seen as initial lesions, but Wilms' tumor and retinoblastoma were over-represented and leukemia and brain tumors underrepresented. Survival variation as well as tumor susceptibility may be responsible for this disproportion. Osteosarcomas and chondrosarcomas were the most frequent second malignant neoplasms (SMN). Embryonal tumors were rare as SMN and adult-type tumors (carcinomas) appeared at earlier than expected ages, whether arising after irradiation or not related to that form of therapy. Radiation was associated with 69 SMN, genetic disease accounted for 27 SMN and both conditions were noted in 15 SMN. In the group of 21 patients for whom neither radiation nor a known genetic disorder could be implicated, there were three with colon carcinoma and glioma and five with leukemia or lymphoma and glioma. These combinations may reflect new tissue-specific hereditary cancer syndromes.

Chemical carcinogenesis and experimental models using human tissues

The majority of human cancer is caused by environmental agents including chemical carcinogens. These chemical carcinogens are both naturally-occurring compounds and products of an industrialized society. Most of the environmental chemical carcinogens require enzymatic activation into electrophilic metabolites which readily react with cellular macromolecules leading, in some cases, to malignant transformation of target epithelial cells. Model systems for studying carcinogenesis in human target tissues are being developed to link investigations using experimental animals with human cancer. Metabolism of chemical carcinogens is being studied in human tissues maintained in these model systems. For example, a marked variation among individuals in their capacity to metabolize carcinogenic polynuclear aromatic hydrocarbons has been observed. This inter-individual variation may, in part, be due to genetic factors. Model systems using human tissues should be useful in several areas of cancer research including: 1) identifying environmental carcinogens, their metabolic pathways and host factors determining susceptibility; and 2) testing new methods of prophylatic intervention in populations at high risk of developing cancer.

Benzo(a)pyrene diol epoxides as intermediates in nucleic acid binding in vitro and in vivo

Evidence has been obtained that a specific isomer of a diol epoxide derivative of benzo(a)pyrene, (+/-)-7 beta,8alpha-dihydroxy-9alpha, 10alpha-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene, is an intermediate in the binding of benzo(a)pyrene to RNA in cultured bovine bronchial mucosa. An adduct is formed between position 10 of this derivative and the 2-amino group of guanine.

Decreased risk of radiation-associated second malignant neoplasms in actinomycin-D-treated patients

One hundred two long-term survivors of childhood cancers with second malignant neoplasms (SMNs) were collected from 10 institutions. Forty-seven cases fulfilling study criteria were studied to determine the risk of developing a SMN in irradiated fields after exposure to various chemotherapeutic agents. The case control method was used. The risk of developing such tumors was decreased by a factor of 7 in patients receiving actinomycin-D (AMD). The "protective" effect of AMD was more pronounced in patients receiving repeated courses of the agent. No change in relative risk was found for children given antifolates, the vinca alkaloids, or alkylating agents. AMD "protection" is an unexpected finding because the agent is an oncogen in animals and an enhancer of radiation, the latter being a known carcinogen. Possible mechanisms, which remain speculative, are discussed. These results indicate the need for careful long-term observation of cancer survivors to gain understanding of the late effects of multimodal treatments.

Correlations of scores on the Wechsler Intelligence Scale for Children and the Peabody Picture Vocabulary Test for adolescents in a special educational program

The Wechsler Intelligence Scale for Children and the Peabody Picture Vocabulary Test were administered to 159 socio-economically deprived Negro adolescents who had been placed in a special educational setting. Ages ranged from 12 to 15 yr., with a mean age of 138 yr. The Wechsler mean Full Scale IQ was 72.4 with a standard deviation of 9.8. Analyses yielded no significant differences between the Verbal and Performance sections of the Wechsler scale and there were no distinctive Wechsler subtest profiles discernible. Inter-correlations of the Wechsler subtests were similar to those reported in the Wechsler manual. While the obtained mean Peabody IQ closely approximated the mean Wechsler IQ, intercorrelations between the Peabody IQ and the Wechsler Full Scale, the Wechsler Verbal, and the Wechsler Performance IQs were relatively low. A statistical test showed a clear cumulative age deficit.

Intelligibility of connected discourse

An approach to measuring the intelligibility of free-running connected discourse that contrasts with the quasi-statistical methods generally used with nonsense syllables, words, or sentences is described. With this approach, intelligibility is viewed as a decision by the listener that specifies how well the message was understood. The goal of testing, therefore, is to quantify the listener’s response with meaningful indices of performance. The various speech-Bekesy procedures are sensitive to a listener decision, but they fail to specify how the criterion of intelligibility was interpreted by the listener and have the additional disadvantage of specifying intelligibility as a threshold level in decibels rather than as a magnitude of intelligibility in percent. Experiments are reported in which systematic modifications were made to the speech-Bekesy procedures. The two major methods are “tracking to constant percentage criteria of intelligibility” and “estimation of intelligibility.” The results specify intelligibility of connected discourse by a performance-intensity function. The data are stable across alternative testing methods and compare favorably with sentence-repetition scores.

Image Analysis Illustrated With A Spearman Case

Because one can write the inverse of the correlation matrix in an extremely simple fashion when the variables form a perfect Spearman case, it is possible to use such a case to illustrate some well-known princeples in component and factor analysis.

"Fixed" splitting of the second heart sound in ventricular septal defect

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