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Biomedical subjects

C C Chu

Publications and source records attributed to C C Chu.

At least 145 records · Page 8Linked to original sources
PubMed1985

Differences in psychopathology between black and white schizophrenics.

The psychopathology of black and white schizophrenics was compared in 275 consecutive admissions of schizophrenics, who were rated on two rating scales by psychiatrists, using a structured interview. There were significant differences between black and white schizophrenics; blacks exhibited more frequent symptoms of angry outbursts, poor communication, disorientation, asocial behaviour and auditory and visual hallucinations, while whites showed more frequent symptoms of unsystematized delusions. When controlled for sex, additional symptom differences were found for female schizophrenics; blacks were more often excited, ambivalent, rigid and dysphoric. For male schizophrenics, all symptom differences disappeared except one; blacks were more frequently asocial.

Black or African American↗
PubMed1985

Psychosocial and environmental variables in outcome of black schizophrenics.

Psychosocial and environmental variables associated with the black schizophrenic patient's discharge from the hospital, community adjustment, and rehospitalization, if any, were examined. Numerous significant variables related to the outcome were identified on the medical, nursing, and social work question-naires through personal interviews with 128 black schizophrenic patients and their families.

Adolescent↗
PubMed1984

Effects of physical configuration and chemical structure of suture materials on bacterial adhesion. A possible link to wound infection.

The purpose of this study was to examine the effects of physical configuration and the chemical nature of suture materials on the preferential adherence of bacteria. Ten suture materials of 2-0 (chromic catgut, Dexon, Vicryl, PDS, Mersilene, Tycron, Ethibond, Surgilon, Ethilon, and Prolene) were used. The bacterial strains tested were Staph. aureus and E. coli. The level of bacterial adherence was determined quantitatively by radiolabelled cells and qualitatively by scanning electron microscopy. It was found that the amount of adhered bacteria depended on the type of suture material, the type of bacteria, and the duration of contact. In the group of absorbable sutures, the new PDS sutures exhibited the smallest affinity toward the adherence of both E. coli and Staph. aureus. Dexon sutures had the highest affinity toward these two bacteria. With nonabsorbable sutures, the physical configuration of the sutures contributed more to their ability to attract bacteria than the surface finish. The bacterial adherence on suture materials was also time dependent. Scanning electron microscope morphologic observation also indicated that Staph. aureus adhered on the suture surface in clusters whereas E. coli tended to adhere individually.

Absorption↗
PubMed1984

Diazepam in intractable sleepwalking: a pilot study.

Nightly ingestion of diazepam, 10mg, alleviated some or all symptoms of intractable sleepwalking in several otherwise healthy adults. Some other patients did not respond as well. The results of this double-blind, crossover study suggest that diazepam is effective for the treatment of adult sleepwalking in some individuals. Data from this study are consistent with uncontrolled case reports of such treatment. Serious side effects or tolerance to the medication did not develop in any of the subjects studied. Other benzodiazepines, which may be more or less effective, remain unstudied. Psychiatric and social histories of these adult sleepwalkers are consistent with earlier work by the authors, which indicates little evidence for an association between uncomplicated sleepwalking and serious psychopathology.

Adult↗
PubMed1983

The effect of gamma irradiation on the enzymatic degradation of polyglycolic acid absorbable sutures.

The purpose of the study was to examine the effect of gamma irradiation on the enzymatic as well as the in vivo degradation of polyglycolic acid sutures. The sutures of size 2-0 were irradiated at dosage levels of 0-20 mrad. The three enzymes chosen for this study were esterase, alpha-chymotrypsin, and trypsin. The irradiated sutures were both immersed in the enzyme solutions; their corresponding buffer controls, and implanted in inbred black-and-white hooded hister rats (Liverpool strain). The degradation of PGA sutures was determined mechanically. Among the three enzymes studied, esterase showed the highest enzymatic effect on the degradation of the unirradiated and irradiated PGA sutures. Trypsin's effect on PGA sutures was not observed until 20 mrad. The findings of trypsin demonstrated the hypothesis that synthetic high molecular weight polymers, which are initially resistant to enzymatic degradation, could become prone to enzymatic attack after altering their physical and chemical structures. Implanted PGA sutures maintained a similar or slightly higher mean tensile breaking strength in in vivo degradation compared to in vitro degradation (0.1M tris buffer of pH = 7.5); these degradation profiles suggest that PGA does not display similar behavior in in vivo and in vitro degradations. The magnitude of dissimilarity depends on the radiation dosage and on the duration of degradation, and is speculated to be attributable to the specific action of enzymes with respect to the configuration and chemical structure of the PGA sutures.

Biodegradation, Environmental↗
PubMed1983

The BPRS in assessing symptom correlates of cerebral ventricular enlargement in acute and chronic schizophrenia.

The present study was an attempt to investigate hypotheses about the interrelationship of brain dysfunction and symptoms of schizophrenia using the Brief Psychiatric Rating Scale (BPRS) and a measure of cerebral ventricular size. The ventricular brain ratio (VBR) was correlated with admission and discharge scores on the BPRS in 46 schizophrenic patients. A significant relationship was found between VBR and discharge BPRS scores. In general, the results were partially supportive of relationships found between neuropsychological data and the BPRS in a previous study, but shed little light on the relationships between brain damage and negative and positive symptoms. Limitations of using the BPRS, as well as possible sampling variations, are discussed.

Acute Disease↗
PubMed1983

An in vitro evaluation of the stability of mechanical properties of surgical suture materials in various pH conditions.

The effects of pH on the tensile properties of eight commonly used 2-0 suture materials--plain catgut, Dexon, Vicryl, silk, Nurolon, Ethilon, Mersilene, and Prolene--were examined. The pH level ranged from 3.0 to 10.0. In general, absorbable suture materials were more sensitive to pH than non-absorbable suture materials; within the same suture materials, a strong alkaline condition would have a more adverse effect on the strength of suture materials than physiologic and acidic pHs. Plain catgut sutures lost relatively significant amounts of strength at both acidic and alkaline conditions when compared with Dexon and Vicryl sutures; hence, precaution should be taken when they are used in closing tissues in contact with acidic environment like the stomach. Among the non-absorbable suture materials, silk and Nurolon exhibited the largest loss of strength in both alkaline and acidic environments after one month, while other sutures retained almost all of their original strength. Physical configuration of the suture materials seemed also to contribute to the sensitivity of suture materials toward pH. A comparison of Nurolon and Ethilon sutures demonstrated this point of view.

Absorption↗
PubMed1983

ECT for major depression in a patient with acute brain trauma.

A woman with depression and cerebral cortical laceration caused by a self-inflicted gunshot wound received ECT 3 weeks after wounding herself and had no untoward effects. The authors discuss relative contraindications to ECT based on head injury and posttraumatic seizures.

Adult↗
PubMed1982

The effect of pH on the in vitro degradation of poly(glycolide lactide) copolymer absorbable sutures.

The pH effect on the hydrolytic degradation of Polyglactin 910 copolymer was studied in terms of the tensile properties of the suture specimens. The use of a cord/yarn grip, newly designed specifically for fibrous materials, eliminated the grip-induced failure. Different degrees of hydrolytic degradation of this copolymer at 3 different pH levels were observed. The suture specimens exhibited the best retentions of breaking strength at the physiological pH of 7.44, while the specimens at pH = 10.09 showed the fastest loss of breaking strength. Thus, a maximum retention of tensile properties occurred around the pH level of 7.0, whereas smaller percentages of retention of tensile properties were observed at both acidic and strong alkaline solutions. This synthetic absorbable suture material exhibits the basic characteristic of hydrolysis which is catalyzed by both acid and base.

Biodegradation, Environmental↗
PubMed1982

Scanning electron microscopic study of the hydrolytic degradation of poly(glycolic acid) suture.

This article reports the morphological observations on the surface changes of poly-(glycolic acid) sutures which have been exposed to various dosages of gamma irradiation (0, 2.5, 5.0, 10, 20 and 40 Mrad) and duration of immersion (0, 7, 14, 28, 48, 60, and 90 days) in a physiological saline buffer. The most important gross morphological characteristics of PGA suture hydrolytic degradation is the formation of surface cracks on the filaments. The regularity of the surface cracks increased with an increase in the gamma irradiation and the duration of hydrolysis. Surface cracks were not observed in irradiated sutures that had not been subjected to hydrolytic degradation. The arrangement of the surface cracks, their orientation on the filaments, and the direction of crack propagation provide very useful information for depicting the mechanism of hydrolytic degradation in this class of fibrous material. The microfibrillar model of fiber structure has been used as the basis for the proposed degradation mechanism of PGA in vitro. It is believed that hydrolysis occurs initially in the amorphous regions sandwiched between two crystalline zones, as tie-chain segments, free chain ends, and chain folds in these regions degrade into fragments. As degradation proceeds, the size of the fragments reaches the stage at which they can be dissolved into the buffer medium. This dissolution removes the fragments from the amorphous regions, and surface cracks appeared.

Chemical Phenomena↗
PubMed1982

A comparison of the effect of pH on the biodegradation of two synthetic absorbable sutures.

The differences in hydrolytic degradation of two size 2-0 synthetic absorbable sutures, Polyglycolic acid (Dexon) and Poly(glycolide-lactide) (Vicryl), in the buffer media of three different pH levels ranging from 5.25 to 10.09, were compared in terms of the percentage retention of tensile strength. It was found that Vicryl sutures, in general, exhibited better retention of tensile strength than Dexon sutures within the studied pH range and extent of hydrolysis. When comparing Vicryl with Dexon sutures, the former was only slightly better than Dexon sutures, in the case of an acid environment. The former, however, retained better strength than the latter in a physiological pH (7.44) and under high-alkaline conditions (10.09). Among the three pH levels tested, Vicryl sutures retained the highest tensile strength in a physiological pH and showed a faster loss of tensile strength in both acidic and high-alkaline conditions. Dexon sutures, however, exhibited better retention of tensile strength in the acidic medium than in an alkaline medium. This pH dependent hydrolysis of Dexon and Vicryl sutures should command surgeons' attention in their selection of synthetic absorbable suture materials for particular needs.

Biodegradation, Environmental↗