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Biomedical subjects

G D Harris

Publications and source records attributed to G D Harris.

At least 37 records · Page 2Linked to original sources
PubMed1989

Preoperative spirometry before abdominal operations. A critical appraisal of its predictive value.

Preoperative spirometry is commonly ordered before abdominal surgery, with the goal of predicting and preventing postoperative pulmonary complications. We assessed the evidence for this practice with a systematic literature search and critical appraisal of published studies. The search identified 135 clinical articles, of which 22 (16%) were actual investigations of the use and predictive value of preoperative spirometry. All 22 studies had important methodological flaws that preclude valid conclusions about the value of screening preoperative spirometry. The available evidence indicates that spirometry's predictive value is unproved. Unanswered questions involve (1) the yield of spirometry, in addition to history and physical examination, in patients with clinically apparent lung disease; (2) spirometry's yield in detecting surgically important occult disease; and (3) its utility, or beneficial effect on patient outcome. Spirometry's full potential for risk assessment in the individual patient has not yet been realized.

Abdomen↗
PubMed1988

Characterization of inositol 1,4,5-trisphosphate-stimulated calcium release from rat cerebellar microsomal fractions. Comparison with [3H]inositol 1,4,5-trisphosphate binding.

The abilities of D-myo-inositol phosphates (InsPs) to promote Ca2+ release and to compete for D-myo-[3H]-inositol 1,4,5-trisphosphate [( 3H]Ins(1,4,5)P3) binding were examined with microsomal preparations from rat cerebellum. Of the seven InsPs examined, only Ins(1,4,5)P3, Ins(2,4,5)P3 and Ins(4,5)P2 stimulated the release of Ca2+. Ca2+ release was maximal in 4-6 s and was followed by a rapid re-accumulation of Ca2+ into the Ins(1,4,5)P3-sensitive compartment after Ins(1,4,5)P3, but not after Ins(2,4,5)P3 or Ins(4,5)P2. Ca2+ re-accumulation after Ins(1,4,5)P3 was also faster than after pulse additions of Ca2+, and coincided with the metabolism of [3H]Ins(1,4,5)P3. These data suggest that Ins(1,4,5)P3-induced Ca2+ release and the accompanying decrease in intraluminal Ca2+ stimulate the Ca2+ pump associated with the Ins(1,4,5)P3-sensitive compartment. That this effect was observed only after Ins(1,4,5)P3 may reflect differences in either the metabolic rates of the various InsPs or an effect of the Ins(1,4,5)P3 metabolite Ins(1,3,4,5)P4 to stimulate refilling of the Ins(1,4,5)P3-sensitive store. InsP-induced Ca2+ release was concentration-dependent, with EC50 values (concn. giving half-maximal release) of 60, 800 and 6500 nM for Ins(1,4,5)P3, Ins(2,4,5)P3 and Ins(4,5)P2 respectively. Ins(1,4,5)P3, Ins(2,4,5)P3 and Ins(4,5)P2 also competed for [3H]Ins(1,4,5)P3 binding, with respective IC50 values (concn. giving 50% inhibition) of 100, 850 and 13,000 nM. Comparison of the EC50 and IC50 values yielded a significant correlation (r = 0.991). These data provide evidence of an association between the [3H]Ins(1,4,5)P3-binding site and the receptor mediating Ins(1,4,5)P3-induced Ca2+ release.

Animals↗
PubMed1988

Free flap reconstruction of the lower back and posterior pelvis: indications, principles, and techniques.

Reconstructive microsurgery can be successfully applied to major defects of the lower back and posterior pelvis. When present, the superior and inferior gluteal vessels can be excellent free flap recipient vessels. However, if they are absent as a result of trauma or tumor ablation, a wrist carrier can be used to transfer large blocks of tissue in a staged procedure. Five patients are presented with challenging defects for which these techniques were used.

Adult↗
PubMed1987

Initial management of hand injuries in the emergency patient.

Failure to develop a proper routine for complete examination and documentation of the injured hand may result in the inability to make the proper diagnosis. Less than optimal treatment may result. Ultimately, the end result is unnecessary functional loss and, frequently, medical-legal difficulties. Initial emergency department management of acute hand is reviewed: recognition of surgical emergencies, proper initial treatment of tendon and nerve injuries, splinting, and record keeping are emphasized.

Emergencies↗
PubMed1987

The sural artery and vein as recipient vessels in free flap reconstruction about the knee.

The sural artery and vein were used successfully as recipient vessels in nine patients who required free flap reconstruction about the knee. The anatomy of the sural vessels and the potential advantages of their use as free flap recipients are reviewed and discussed. Indications include popliteal vessels that are absent or severely damaged, as determined by preoperative angiography. No anastomotic complications were encountered in this series, indicating that the sural artery and vein can be used successfully as recipient vessels.

Adolescent↗
PubMed1987

Accelerating recovery after trauma with free flaps.

Free flap versatility and dependability make the final result of microvascular reconstruction highly predictable. Free tissue transplantation should be considered as a primary treatment after trauma. The early use of free tissue transfer will result in fewer operations and a shortened duration of hospitalization in the initial post-trauma period.

Humans↗
PubMed1987

Fluid balance and the adult respiratory distress syndrome.

This study examined the effect of fluid balance on survival in ARDS. Of the 213 patients entered into a prospective data collection study, we evaluated 113 patients who met strict criteria for ARDS. Multiple variables were analyzed for as long as 14 days after intubation including cardiac output, pulmonary capillary wedge pressure, mean blood pressure, intake minus output (I-O), cumulative intake minus output (cum I-O), and change in weight (delta wt). We found significant differences in cum I-O and delta wt between survivors and nonsurvivors on almost every day. Survivors lost weight and had a significantly lower cum I-O compared with nonsurvivors. Logistic regression was used to determine if delta wt and cum I-O could predict survival. Patients who lost 3 kg or more weight had a much higher survival than did those who gained 3 kg or more weight (67 and 0%, respectively, on Day 14). Similar results were obtained using comparably low and high values for cum I-O. The logistic regression equations demonstrated that weight loss and low cumulative I-O correlated with improved survival. Although cause and effect relationships are difficult to determine from these types of analyses, they can be used to formulate prospective studies and predict survival in patients.

Body Weight↗
PubMed1987

The dorsal thoracic fascia: anatomic significance with clinical applications in reconstructive microsurgery.

The anatomic distribution and potential arterial flow patterns of the circumflex scapular artery were investigated by Microfil injection. These studies demonstrated that the circumflex scapular artery lies within the dorsal thoracic fascia, which plays a significant role in the circulation of the overlying skin and subcutaneous tissue. We conclude that scapular/parascapular flaps are fasciocutaneous flaps, the dorsal thoracic fascia can be transferred as a free flap without its overlying skin and subcutaneous tissue, and intercommunication exists between the myocutaneous perforators of the latissimus dorsi myocutaneous flap and the vascular plexus of the dorsal thoracic fascia. We present microvascular cases in which the vascular properties of the dorsal thoracic fascia facilitated wound closure with free fascia flaps or expanded cutaneous or myocutaneous flaps.

Adult↗
PubMed1986

Incidence, site, and outcome of infections in patients with the adult respiratory distress syndrome.

Bacterial infection in the adult respiratory distress syndrome (ARDS) is associated with the occurrence of multiple organ failures and death. We studied 108 infections in 129 patients with ARDS and evaluated the organisms responsible, the body sites involved, and the outcomes of therapy. Gram-negative bacilli represented 57% of the microbial pathogens and gram-positive cocci 36%. Only 7% of infections were caused by other organisms (fungi, viruses, Pneumocystis, Legionella). Gram-negative organisms were more common in the lung, abdomen, and pleura. Bacteremia was more common in abdominal infections (11 of 17, 67%) than in infections at other sites (18 of 65, 28%), (p less than 0.01); ;9 patients were bacteremic from clinically undetected sites. Ten of 17 (59%) patients with abdominal infections survived compared with 7 of 56 (13%) patients with lung infections (p less than 0.001). A retrospective review of in vitro organism susceptibility and the antibiotics administered revealed that the patients who received adequate antibiotic therapy did not have a higher survival rate (20 of 69, 29%) than those who received inadequate antibiotic therapy (3 of 13, 23%). These data suggest that further investigation of infections in patients with ARDS is required and that emphasis should be placed on pathogenesis, prevention, and host responses.

Adult↗
PubMed1983

Effects of three types of lecture notes on medical student achievement.

Two parallel studies were conducted with junior medical students to determine what influence the forms of lecture notes would have on learning. The three types of notes given to the students were: a comprehensive manuscript of the lecture containing text, tables, and figures; a partial handout which included some illustrations but required substantial annotation by the students; and a skeleton outline containing no data from the lecture. The students' knowledge about the subject was measured before the lecture, immediately after the lecture, two to four weeks later, and approximately three months later. The students' responses to questionnaires indicated a strong preference for very detained handouts as essential to preparation for examinations. By contract, the students' performances on tests generally were better for those who had received the partial or skeleton handout formats. This was particularly true for information presented during the last quarter of each lecture, when learning efficiency of the skeleton handout group increased while the other two handout groups exhibited learning fatigue. It was concluded that learning by medical students was improved when they recorded notes in class.

Achievement↗
PubMed1983

A clinical information consultation service at a teaching hospital.

The library and the department of medicine at the University of Texas Health Science Center at San Antonio cooperated in a three-month pilot project to test a clinical information consultation service that provides patient care information to house staff members in the clinical setting. Evaluation indicated that users were highly satisfied with the service. Results of our pilot project seem to show that a clinical information consultation service can be an efficient and cost-effective means to provide information in a patient-care setting.

Hospitals, Teaching↗
PubMed1981

Posterior-wall-first microvascular anastomotic technique.

A posterior-wall-first anastomotic technique has significant advantages over the traditional method of microvascular anastomosis. Since July, 1979, the posterior-wall-first anastomosis has been used in 17 consecutive replantations involving 31 fingers or parts with a success rate of 97%. In addition 20 composite tissue transplants were carried out using the same technique with a success rate of 95%. The technique is described in detail and the advantages clearly stated.

Fingers↗
PubMed1981

The microvascular anastomotic autogenous cuff.

A carefully controlled experimental study of the haemostasis time and the patency rates in microvascular anastomoses of the rat femoral artery shows very high patency rates in 0.8-1 mm vessels with only four sutures and with the use of anastomotic autogenous cuffs to provide immediate haemostasis. The "posterior-wall-first" technique of anastomosis was performed in all cases. Not only are fewer sutures required: vascular trauma is reduced, less foreign material is introduced at the site of anastomosis and the time to complete the anastomosis is reduced. The results of this study have obvious clinical applications.

Animals↗
PubMed1980

Aspiration pneumonia, anaerobic infections, and lung abscess.

Anaerobic pleuropulmonary infections are common in the setting of aspiration. Treatment is with penicillin or in mixed infections, penicillin and other appropriate antimicrobial agents. Four syndromes are commonly recognized. Simple pneumonitis resolves promptly with antibiotic therapy. If treatment is delayed, simple pneumonitis may evolve into a more fulminant process of necrotizing pneumonia with a significant mortality despite antibiotic therapy. Lung abscess, typically a subacute or chronic infection, responds well to antibiotic therapy so long as the cavity is drained via the communicating bronchus. Empyema requires surgical drainage by either closed or open thoracostomy if resolution is to be achieved.

Anti-Bacterial Agents↗