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Biomedical subjects

C C Baker

Publications and source records attributed to C C Baker.

At least 145 records · Page 8Linked to original sources
PubMed1979

Septic phlebitis: a neglected disease.

A review of 100 patients with peripheral septic phlebitis revealed that 54 per cent of the cases were due to intravenous catheters and 46 per cent were secondary to drug abuse. Eighty per cent of the involved veins were in the arm or neck. Pain was the most common symptom (83 per cent), with erythema and edema the most common physical signs (63 per cent). Eighty per cent of the causative organisms were gram-positive bacteria, usually Staphylococcus aureus (41 per cent) or Group A streptococcus (20 per cent). Complications were more common if septic phlebitis was due to intravenous therapy than drug abuse. No deaths were directly attributed to septic phlebitis. However, hospital stay after development of septic phlebitis was 14 days with a 56 per cent complication rate. The initial treatment of septic phlebitis should include prompt removal of the intravenous device, antibiotics, heat, and elevation. Because serious complications occur in a significant number of patients, operative excision of the involved vein should be performed if clinical deterioration occurs or if septicemia persists after 24 hours despite conservative therapy.

Arm↗
PubMed1979

Messenger RNA for the Ad2 DNA binding protein: DNA sequences encoding the first leader and heterogenity at the mRNA 5' end.

During the early stage of Ad2 infection of human cells, RNA is transcribed from five separate transcription units. Early region II encodes the mRNA for a 72K single-stranded DNA binding protein (DBP) which functions in DNA replication. This report describes the structure of the first leader of the DBP mRNA and the flanking sequences in the DNA. The leader, labeled in vivo with 32P, was isolated by DNA filter hybridization to the viral restriction fragment Eco RI F, and its RNAase T1 and RNAase A oligonucleotides were analyzed by RNA fingerprinting techniques. Comparison of this RNA sequence information with the DNA sequence of Eco RI F has located a 68 nucleotide region of the Hae III C subfragment at coordinate 75.1 that encodes the leader. This position is near the coordinate to which nascent chain analysis and ultraviolet transcription mapping have mapped an RNA initiation site, or promoter, for the DBP mRNA. The DNA sequence that overlaps the leader on the 3' side contains a donor sequence for splicing this leader to a second downstream leader. The splicing sequence shows a seven base homology with the comparable structure of the Ad2 major late leader, and a mouse globin mRNA splicing sequence. The DNA sequence upstream from the cap, the region oof the potential promoter site does not, however, contain a "TA-TAAA"-type homology of the sort noted by D. Hogness, M. Goldberg and R. Lifton (personal communication) for many cellular transcription units, and by other investigations for the Ad2 major late transcription unit. Also, the leader is found with two distinct capped 5' termini, 7meGpppA and 7meGpppG, which are encoded at adjacent positions in the DNA and thus are from mRNAs which are staggered by one nucleotide in length at the 5' end. The staggering at the 5' terminus and the lack of the upstream homolgy distinguish the DBP mRNA from many viral and cellular messenger. In both these respects, however, the DBP mRNA resembles the late messengers of SV40 and polyoma viruses. In this paper, we discuss the implications of these findings for the mechanism of specifying mRNA 5' ends.

Adenoviruses, Human↗
PubMed1979

Predicting fatal sepsis in burn patients.

The high morbidity after severe thermal insult is believed to be related partially to a resultant decrease in immunocompetence. We tested the ability of phytohemagglutinin (PHA) and Concanavalin (Con A) to stimulate lymphocyte transformation in 17 patients with moderate to severe thermal injury (greater than 25% BSA). The patients acted as their own controls and the per cent change in their mitogen response was measured over time. Eight acutely burned patients who subsequently developed severe sepsis (Group I) had decreased ability (mean, 12% of normal) to proliferate in response to PHA, and six of these died of severe sepsis. The depressed response appeared 4 to 7 days postinjury and predated clinical evidence of sepsis by 2 to 4 days. Cells from four patients who had mild infectious complications (Group II) demonstrated greatly augmented mitogen responses (mean + 243%) approximately 7 to 10 days postinjury. Five burn patients whose clinical course was sepsis free (Group III) exhibited only minimal changes in their mitogen responses (mean +30%). Although the Con A responses of the patients' cells corresponded less to their pathology, Group I patients whose cells exhibited depressed PHA responsiveness also had diminished Con A responses. Group II patients' cells also showed increases in Con A-induced stimulation. Group III patients, who had only slightly augmented PHA responses, had minimal decreases of the Con A-induced lymphocyte transformation. Many severely burned patients develop septicemia as a result of their large wound surfaces. The appearance of decreases in mitogen-induced proliferation, however, appears to characterize those patients who will be unable to handle the septic challenge.

Adult↗
PubMed1979

Changes in lymphocyte activity after thermal injury. The role of suppressor cells.

The high incidence of fatal septicemia associated with severe thermal injury is believed to result from a loss of immunocompetence. To detect burn-mediated immune defects, lymphocyte function in peripheral blood leukocytes from 18 individuals sustaining 20-80% full thickness thermal burns was investigated. We examined the kinetics of the mitogen responses, the development of suppressive activity, and the correlation of mononuclear cell functional abnormalities with the incidence of sepsis. Patients were divided into three groups corresponding to their clinical course. The phytohemagglutinin responses of Ficoll-Hypaque purified leukocytes from eight of these patients (group III) were normal at day 1-2 after injury, but were significantly depressed (mean 16% of normal) at days 5-10 after injury. All of these group III patients experienced multiple, severe, septic episodes, and septic mortality was 75%. The other 10 burned individuals showed either augmented (group II) or unaltered (group I) mitogen responsiveness. Concomitant with evaluation of their mitogen responses, the cells of burn patients were assessed for development of suppressive activity by addition to on-going normal mixed leukocyte reactions (MLR). Only the addition of mononuclear cells with depressed phytohemagglutinin responsiveness (group III) significantly decreased MLR proliferation (mean 80% reduction) by the previously highly responsive, normal MLR combinations. Addition of cells from group III burn patients collected immediately after injury had no suppressive effect. Addition of cells from patients in group I or II or of normal individual's cells had no suppressive effect. These experimental results strongly suggest that a suppressive mononuclear cell is at least partially responsible for the decreased immunocompetence of burn patients.

Adult↗
PubMed1977

Subclavian subtleties.

Several helpful technical features are presented that reduce the morbidity associated with subclavian vein catheterization. These techniques include percutaneous insertion through an indwelling catheter, repositioning the catheter without a second puncture, and securing the catheter without kinking or dislodgment. Use of these techniques will spare the patient the risks attendant to multiple subclavian punctures.

Catheterization↗
PubMed1976

On the analysis of circular dichroic spectra of proteins.

A new method is presented for analyzing circular dichroism spectra. The method employs integrals over the data and calculates the alpha-helical, beta-sheet, and random coil content of the proteins from such integrals. It is shown that the analyzed alpha-helical content is usually reliable to within 5%, beta-sheet values are somewhat less reliable, and random coil values are least reliable. Curve fitting techniques are shown to be misleading. The method has a number of advantages over existing procedures.

Circular Dichroism↗
PubMedDate not supplied

Efficacy and tolerability of subcutaneous sumatriptan administered using the IMITREX STATdose System.

The efficacy and tolerability of subcutaneous (SC) sumatriptan administered with the IMITREX (sumatriptan succinate) STATdose System, which circumvents the need for patients or health care professionals to handle a syringe, were evaluated in two randomized, double-masked, parallel-group, placebo-controlled, multicenter studies. In the clinic, 158 adults with migraine diagnosed according to International Headache Society criteria received SC sumatriptan (6 mg) or placebo delivered with the IMITREX STATdose System for treatment of a migraine attack. By 120 minutes after SC dosing, 73% and 79% of sumatriptan-treated patients, compared with 28% and 37% of placebo-treated patients in studies 1 and 2, respectively, experienced headache relief (a statistically significant difference). Clinical disability scores 120 minutes after dosing showed that 75% and 85% of sumatriptan-treated patients, compared with 30% and 42% of placebo-treated patients, were normal or only mildly impaired (a statistically significant difference). Similar efficacy rates were observed for nausea, phonophobia, and photophobia. No serious or unusual adverse events occurred, and no clinically relevant abnormalities in laboratory test values were reported. Based on these results, we concluded that SC sumatriptan (6 mg) administered using the IMITREX STATdose System is effective for the treatment of migraine. The efficacy and tolerability profiles of SC sumatriptan administered with this device are similar to those reported for SC sumatriptan administered with a conventional syringe.

Adult↗
PubMedDate not supplied

Immunologic alterations following excisional wounding and immediate repair with syngeneic or allogeneic skin grafts.

Immunosuppression and its associated infectious complications have long been recognized as consequences of major thermal trauma, though the factors that mediate this suppression remain unclear. A murine split-thickness skin graft model was developed to investigate the role of a large surface area wound in the initiation of immunosuppression in the absence of burn injury. Significant T cell-mediated immunosuppression was demonstrated following wounding and immediate repair with either syngeneic or allogeneic split-thickness skin grafts. These results are consistent with previous experiments in a murine burn model treated by escharectomy and resurfacing with syngeneic composite full-thickness skin. Data also supports the concept that mediators of inflammation at the wound site play an important role in postburn immunosuppression. Furthermore, these results suggest that the use of skin allografts during the early postburn period does not adversely affect cell-mediated immunity in any way that could be abrogated by primary autografting.

Animals↗
PubMedDate not supplied

Pentoxifylline alters class-specific immunoglobulin synthesis in resuscitated burn injury.

Pentoxifylline (PTXF) is a hemorheologic agent that can attenuate microvascular alterations induced by injury, resulting in improved microcirculatory flow. Burn injury-induced immunologic suppression may be caused by alterations in microvascular flow. We studied the effects of PTXF on humoral immunity in resuscitated burn injury. Male AKR mice (n = 80) were randomized to four groups: SHAM, BURN, PTXF-BURN, and NS-BURN (saline burn). Animals were resuscitated with Ringer's lactate and morphine sulfate and put to death at days 1 and 4 after injury. PTXF-BURN animals received PTXF (50 mg/kg intraperitoneally) at the time of resuscitation. Splenic lymphocytes (1 x 10(6) cells/well) were cultured with lipopolysaccharide (LPS) (2.5 and 10 micrograms/ml)). LPS-stimulated in vitro class-specific immunoglobulin (Ig) production was determined by enzyme-linked immunosorbent assay from splenic cell culture supernatants. Burn injury induced a reduction in immunoglobulin (Ig) M synthesis on postburn day 4. PTXF treatment was associated with an increase in IgG production, but a greater depression in IgM synthesis than burn injury alone. PTXF administration during resuscitation in burn injury does not ameliorate the burn-induced depression in IgM synthesis and results in significant potential adverse modulation of humoral immune function.

Animals↗
PubMedDate not supplied

Interleukin-1 and T cell function following injury.

Sepsis is responsible for 75% of late deaths after major thermal or traumatic injury. In the clinical setting, efforts to prevent or control sepsis, or both, should include an understanding of normal host resistance, proper resuscitation techniques, and nutritional support. Previous studies have identified T suppressor cell abnormalities following thermal injury and have suggested macrophage defects after traumatic injury. Although major thermal injury is easier to quantify than mechanical trauma, both insults can stress patients' host resistance to a maximal degree, leading to profound and often fatal immunosuppression. Recent studies summarized in this paper have suggested that the macrophage and the interleukin system may play a major role in initiating some of these immune abnormalities following injury.

Animals↗
PubMedDate not supplied

Immune mechanisms and host resistance in the trauma patient.

Sepsis is responsible for 75 percent of late deaths following major thermal injury or traumatic injury. Efforts to prevent and/or control sepsis should include an understanding of normal host resistance, proper resuscitation techniques, and nutritional support. Recent studies identifying T suppressor cell abnormalities in burn patients and macrophage defects in trauma patients are presented in this paper. Concluding remarks regarding future directions for research and therapy in this area are also made.

Bacterial Infections↗
PubMedDate not supplied

The adult respiratory distress syndrome.

The adult respiratory distress syndrome (ARDS) represents a common denominator of acute lung injury leading to alveolar flooding, decreased lung compliance, and altered gas transport. In the absence of specific etiology and therapy, the management of ARDS remains largely supportive. Ubiquitous use of intermittent positive-pressure ventilation with positive end-expiratory pressure (PEEP) improves arterial oxygenation but with some risk of pulmonary barotrauma and decreased cardiac output. The recent understanding of lung inflation as a modulator of right heart afterload and the effect of the right ventricle on global cardiac performance continues to redefine optimal patterns of ventilatory and hemodynamic intervention in ARDS.

Capillary Permeability↗