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Biomedical subjects

R W Baker

Publications and source records attributed to R W Baker.

At least 19 recordsLinked to original sources
PubMed1992

Emergence of obsessive compulsive symptoms during treatment with clozapine.

BACKGROUND: Clozapine differs from other currently available antipsychotics in its prominent serotonin blockade. We explore the relationship between clozapine and obsessive compulsive symptoms, which have been linked to deficient serotonin. METHOD: We reviewed our experience in treating 49 chronic schizophrenic patients with clozapine. RESULTS: Five patients were identified who experienced either de novo obsessive compulsive symptoms or exacerbation of preexistent symptoms. Clinical details are provided for each case. CONCLUSION: Clozapine may produce or unmask obsessive compulsive symptoms. This may reflect a variation on the normal course of clinical improvement, or may more specifically result from clozapine's atypical pattern of CNS receptor antagonism. Further attention to this issue is warranted.

Adult↗
PubMed1991

An American Board of Orthodontics case report. Correction of a Class III mandibular prognathism and asymmetry through orthodontics and orthognathic surgery.

The Class III malocclusion with mandibular prognathism can involve many factors, among which are excessive mandibular growth, underdevelopment of the maxilla, environmental factors, and trauma to the jaws. The correction of this malocclusion can involve an orthodontic or a combined orthodontic-orthognathic approach. Skeletal asymmetries can complicate this situation, making treatment either more difficult, more complicated, or both. This case presentation involves treatment with a combined orthodontic-orthognathic approach. [This case was presented to the American Board of Orthodontics in partial fulfillment of the requirements for the certification process conducted by the Board.]

Adolescent↗
PubMed1991

Occlusion as it relates to TMJ. A study of the literature.

References in this report are to papers that basically point toward similar findings. They have helped in the search for the etiology of TMJ dysfunction. We have tried to point out that there is no research that shows that restorative dentistry or orthodontics are etiological factors in TMJ dysfunction. The old bug-a-boo about what causes TMJ--why it is more prevalent in women, etc.--is still under intensive study. Again, we should use a cautious approach to TMJ, be positive, be informed, and proceed with the right method, that is, a valid diagnosis before treatment.

Humans↗
PubMed1990

Family response to improvement by a relative with schizophrenia.

The sudden improvement in long-term schizophrenic patients after treatment with clozapine is frequently disconcerting to their families. In many cases the patients appear to have increased hostility toward their families because of the alleviation of negative symptoms such as apathy and blunted affect. The authors believe that psychoeducational intervention can help families adjust to the change in their family members and describe such intervention with three families. They emphasize the importance of recognizing that a patient's improvement can be a stressor in the family relationship and the need for devising appropriate interventions.

Adult↗
PubMed1988

A symptom rating scale for delirium.

The authors present a 10-item clinician-rated symptom rating scale for delirium. Compared to demented, schizophrenic, and normal control groups, 20 delirious subjects scored significantly higher on the scale, which quantitates multiple parameters affected by delirium. The scale can be used alone or in conjunction with an electroencephalogram and bedside cognitive tests to assess the delirious subject.

Adult↗
PubMed1987

Alterations in ventilatory pattern and ratio of dead-space to tidal volume.

The effects of alterations in ventilatory pattern on the simultaneously measured physiologic and anatomic dead-spaces (VDphys and VDan, respectively) and the dead-space to tidal volume ratio (VD-VT) were studied in 17 healthy normal subjects (13 men, four women, ages 21 to 36 years). There were no significant changes in VDan with increases in respiratory frequency (f) or tidal volume (VT). The VDphys increased (mean change +0.153 L, p less than 0.05) with increase in VT (mean increase +0.84 L, p less than 0.01), but did not alter significantly with a twofold increase in f, at control VT. Increase in VT significantly reduced VD/VT (mean change -10.4 percent, p less than 0.05), but increase in f, at control VT, did not significantly alter VD/VT. These results indicate that in normal subjects, increase in VT alters ventilation/perfusion matching in the lungs, whereas an increase in f, at constant VT, has no effect on ventilation/perfusion matching. Increases in VD/VT cannot, therefore, be ascribed to alterations in ventilatory pattern where either VT, or f, or both are increased.

Adult↗
PubMed1985

Alprazolam withdrawal delirium unresponsive to diazepam: case report.

A case is presented in which a 68-year-old man became delirious after being withdrawn from a low dosage of alprazolam. The delirium was not affected by administration of alprazolam. The authors suggest that alprazolam may have enhanced specificity for a subpopulation of benzodiazepine receptors.

Aged↗
PubMed1984

Retention of intact cells on bronchoscopy brushes after cleaning.

Reusable nylon bristle bronchoscopy brushes were evaluated to assess whether cytologically recognizable cells could be retained on the bristles after conventional cleaning techniques. Twenty brushes were used during bronchoscopy; 5 brushes were inserted directly into freshly resected neoplasms. The brushes were then scrubbed and rinsed in chlorhexidine gluconate, iodine, and alcohol, and air dried. Several days later fresh cytologic specimens were prepared from the apparently clean brushes. Eighty percent of the cytologic specimens exhibited strands of mucus, most containing well-preserved alveolar macrophages, polymorphonuclear leukocytes, and ciliated epithelial cells. Although no malignant cells were retained, it is clear that conventional cleaning techniques are inadequate for the removal of cells and acellular debris. Consideration should be given to immersing brushes in acetylcysteine or employing disposable brushes.

Bronchoscopy↗
PubMed1984

Ventilatory regulation in eucapnic morbid obesity.

In morbid obesity, there is an increased hindrance to breathing caused by the effects of the increased mass on the chest wall and abdomen; subjects with morbid obesity can maintain eucapnia by increasing inspiratory neuromuscular drive and/or by altering central breath timing. We studied 23 eucapnic, obese subjects (greater than 190% predicted ideal weight), 7 males and 16 females with a mean age of 36.6 +/- 9.2 yr and 18 healthy, normal male subjects. Total lung capacity, functional residual capacity, and total thoracic compliance were significantly (p less than 0.05) reduced in the obese subjects. At rest, minute ventilation was significantly increased because of an increase in respiratory frequency, which in turn was due to a significant decrease in the expiratory time (TE) per breath; the ratio of inspiratory to expiratory time (TI/TE) was thus significantly altered, indicating an alteration in central breath timing. Resting inspiratory neuromuscular drive (as represented by mouth occlusion pressure) was significantly increased in the obese subjects, but tidal volume was not significantly altered. There was an increased ventilatory responsiveness to hypoxia and relatively decreased ventilatory responsiveness to hypercapnia in the obese subjects. These results indicate that morbidly obese subjects maintain eucapnia primarily by an alteration in central breath timing. Although these subjects have decreased responsiveness to CO2, putting them at some risk of developing respiratory failure under conditions of hypercapnic/hypoxic stress, it is possible that this is counteracted by the increased responsiveness to hypoxia.

Adult↗
PubMed1983

Controlled release of water-soluble macromolecules from bioerodible hydrogels.

A bioerodible hydrogel based on water-soluble unsaturated polyesters crosslinked through the double bonds and capable of immobilizing water-soluble macromolecules has been developed. As the ester linkages cleave, the entrapped macromolecule is gradually released to the surrounding aqueous environment. In vitro rate of hydrolysis and concommitant macromolecule release can be controlled by constructing unsaturated polyesters containing varying proportions of esters activated by electron-withdrawing substituents vicinal to the ester function and/or by varying crosslink density. Polyesters containing unsaturation either in the polymer backbone or pendant have been prepared. Macromolecule-containing hydrogels have been fabricated as dessicated microspheres that can be resuspended in water and passed through a 22-gauge hypodermic needle.

Biodegradation, Environmental↗
PubMed1981

Intestinal permeability in patients with eczema and food allergy.

Polyethylene glycol (PEG) was used as a probe molecule to investigate intestinal absorption in eight patients with eczema and evidence of food allergy and ten with eczema alone. In both groups absorption of molecules of larger molecular weight was greater than in normal subjects but absorption of molecules of low molecular weight was normal. There was no difference in absorption between eczema patients with or without food allergy. These results suggest that there is an intestinal mucosal defect in eczema which exists whether or not there is coexistent food allergy. Half the patients with eczema alone and two of the eight with food allergy had more of the large molecular weight PEG recovered in their urine in the second 12 h after ingestion than in the first 12 h. This could be the result of abnormal permeability in the more distal small bowel or even in the colon.

Adolescent↗
PubMed1979

Development of an estriol-releasing intrauterine device.

Estriol-releasing intrauterine devices were developed for experimental use in animals and humans. The devices consist of a reservior containing the steroid surrounded by a rate-limiting polyurethane membrane. After an initial transient, the drug is released from the device at a constant rate for 1 year or more; devices with a much longer release period can be fabricated readily. A constant release rate is achieved by maintaining solid drug in the reservoir and good physical contact between the drug and the inside wall of the device. The methods used to fabricate the devices are described along with release rate and stability data.

Chemistry, Pharmaceutical↗