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Biomedical subjects

C Andrews

Publications and source records attributed to C Andrews.

At least 19 recordsLinked to original sources
PubMed1995

The effect of transfection of the CEA gene on the metastatic behavior of the human colorectal cancer cell line MIP-101.

Carcinoembryonic antigen (CEA) has been shown to increase the metastatic potential of some human colorectal cancer cell lines. To investigate further the mechanisms involved we have produced three clones (6, 8 and 17) from the poorly differentiated human colorectal cancer cell line MIP-101 that have been transfected with the full length cDNA encoding for human carcinoembryonic antigen (CEA). They produce CEA with a mol. wt. of 180000 by Western blotting and secrete it into the culture medium. Clone 6 is a high CEA producer, clones 8 and 17 are intermediate producers. The doubling time for clone 8 was similar to that of the parent cell line while clones 6 and 17 had doubling times nearly twice that of the parent cells. These clones are tumorigenic when injected subcutaneously in nude mice are positive for CEA by immunoperoxidase staining and the mice have elevated blood levels of CEA. Clone 6 formed large aggregates in culture while clone 17 formed smaller aggregates. Clone 8 behaved like the parent cell line with rare cell/cell contact. Clones 6 and 17 also adhered to CEA coated plastic while clone 8, a neo-transfected control and the parent cell line did not. A significant increase in the incidence of hepatic tumors was observed with clone 6 (P < 0.01) and clone 17 (P < 0.02) following intrasplenic injection into nude mice. Immunohistopathology of the hepatic tumors showed strong CEA staining from clones 6 and 17 with weak staining from clone 8. The parent cell line was negative for CEA as were the neo-transfected controls. Of the neo controls none of 10 had liver colonies. Mice injected with clone 6 which developed liver metastasis had the highest plasma levels of CEA (37.3 +/- 8.8 ng/ml). We observed strong CEA staining in Kupffer cells in the normal liver adjacent to the CEA producing tumors. This study provides further evidence for the involvement of CEA in the metastatic process.

Adenocarcinoma↗
PubMed1995

Preventing and managing pressure sores in palliative care.

Pressure sore rates were addressed in a palliative care unit by undertaking risk assessment, monitoring wound status and introducing a dressing protocol. A systematic approach to pressure sores in palliative care resulted in a decrease in pressure sore rates in one hospice.

Clinical Nursing Research↗
PubMed1994

Normal colonic epithelium adheres to carcinoembryonic antigen and type IV collagen.

BACKGROUND/AIMS: Human colorectal carcinoma cells bind to collagen and laminin in the basement membrane as well as to carcinoembryonic antigen (CEA) on neighboring cells. The purpose of this study was to determine whether normal colonic epithelial cells bind to CEA, collagen, or laminin. METHODS: Intact colonic crypts were isolated from normal mucosa in 13 specimens resected for colorectal carcinoma or colonic diverticulitis. Colonocytes were released from the crypts by treatment with collagenase and deoxyribonuclease and tested for adhesion to CEA, type IV collagen, and laminin in a solid-phase adhesion assay. RESULTS: Twelve percent to 25% of colonocytes in all specimens bound to CEA. Colonocytes from seven specimens also bound to type IV collagen, but none of the colonocyte preparations bound significantly to laminin. Monoclonal antibodies to CEA and to the hyaluronate receptor CD44 and enzymatic removal of membrane CEA blocked the adhesion of colonocytes to CEA. CONCLUSIONS: First, colonocytes use the same epitopes on CEA and CD44 as colorectal carcinoma cells to adhere to solid-phase CEA. Second, colonocytes bind to solid-phase CEA through CEA-to-CEA homophilic binding. Third, CEA and type IV collagen, but not laminin, are adhesion ligands for human colonocytes.

Antibodies↗
PubMed1994

The OR suite as a unique trauma resuscitation bay.

Trauma is the fourth leading cause of death in the United States, and trauma injuries affect more than 50 million Americans annually. Inadequate care of trauma patients can cause unnecessary patient deaths. To decrease death and disability caused by trauma, one Denver hospital developed a trauma OR based on the "Golden Hour" principle (ie, the sooner a patient receives treatment, the more likely the patient will survive). Since 1977, this hospital has performed 1,838 trauma resuscitations in the trauma OR suite. This article discusses the importance of triage and recants the history of trauma patient transportation. The authors detail the trauma procedures at their hospital, including the specific roles of trauma team members and the necessary equipment, and provide demographic information on the trauma resuscitations performed at the hospital since 1988. The article also discusses the extensive and continuous orientation necessary for trauma team members and explains the quality improvement strategies implemented by this hospital.

Adolescent↗
PubMed1994

A control/experimental trial of an operant treatment for early stuttering.

A preliminary study (Onslow, Costa, & Rue, 1990) suggested that a parent-conducted program of verbal response-contingent stimulation would be an effective treatment for stuttering children younger than 5 years. The present study was designed to expand those preliminary findings by using a larger group of children and by comparing them to a control group of children. Twelve children in the experimental group achieved median percent syllables stuttered (%SS) scores below 1.0 for a 12-month posttreatment period. The children's treatments were completed in a median of 10.5 1-hour clinic sessions and a median of 84.5 days from the start of treatment. The majority of parents of the control children withdrew from the study and elected to have treatment begin for their child. These results suggest that the program may be a cost-effective method for managing a clinical caseload of stuttering children younger than 5 years. It is suggested that controlled clinical trials cannot be used validly or ethically to determine the number of cases of early stuttering who recover without formal intervention.

Age Factors↗
PubMed1994

Stromal tumors of the stomach: prognostic value of the PCNA index.

Reliable indicators of behavior in stromal tumors of the gastrointestinal tract have yet to be elucidated. Aggressive behavior has been associated with large size, hypercellularity, tumor necrosis, nuclear atypia, and high mitotic rate. Recently, new methods of measuring proliferation have been developed that exploit the phenomenon of cell cycle specific protein synthesis. In this study the expression of the S-phase specific nuclear protein proliferating cell nuclear antigen (PCNA) is tested as an indicator of malignancy. Sixteen stromal tumors of the stomach were reviewed for tumor size, cellularity, nuclear atypia, mitotic rate, necrosis, vascular invasion, and predominant cell type. Local recurrence and/or mortality were ascertained with a minimum follow-up of 5 yr. An immunohistochemical assay for PCNA was performed on a paraffin section of tumor and the percentage of positively stained cells ("PCNA index") was determined. Among the nine men and seven women, age 37 to 80 (median 66) yr, two had local recurrences that were treated surgically with no metastases. Only positive resection margin correlated with local recurrence. Two other patients developed distant metastases at 8 and 15 mo and died. Mortality did not correlate with age, sex, size, cellularity, necrosis, cell type, and vascular invasion. High grade nuclear atypia (2/2 versus 1/14, P = 0.02) and high mitotic rate (20.5 versus 5.5 per 40 hpfs, P = 0.01) did correlate with mortality. PCNA index did not correlate with local recurrence, but was sharply higher in fatal cases (6.4 versus 1.2, P = 0.001). Both fatal tumors had PCNA values above 6.0, and all others had values of 4.0 or less. The PCNA index is a proliferative marker that may have prognostic value in gastric stromal tumors.

Adult↗
PubMed1992

DDD pacing mode survival in patients with a dual-chamber pacemaker.

Dual-chamber (DDD) pacing mode survival was assessed by reviewing 486 consecutive initial transvenous DDD pacemaker implantations between December 1981 and December 1988 inclusive, with a mean follow-up time of 33 months. The patients' mean age was 71.4 years and 55% were male; 38% had dominant sinoatrial and 62% had dominant atrioventricular (AV) node disease. Nineteen patients (4%) underwent secondary operative intervention for lead dislodgement (n = 11), lead or pulse generator malfunction (n = 6) or infection (n = 2). During follow-up, 87 patients (18%) had their device permanently reprogrammed out of the DDD mode and 10 others (2%) required temporary reprogramming out of this mode; 12 patients who required device reprogramming were managed in other dual-chamber or atrial pacing modes. Reasons for reprogramming included atrial fibrillation (n = 48; 10%); loss of atrial sensing (n = 26; 5%); recurrent "endless loop" tachycardia (n = 5; 1%); lead dislodgement without repositioning (n = 4; 1%); pulse generator malfunction (n = 1; 1%) and other (n = 5; 1%). The occurrence of atrial fibrillation was associated with dominant sinoatrial disease and a prior history of atrial fibrillation; 19% of atrial sensing loss was attributable to early or faulty pacemaker technology. The DDD mode survival rate at 1, 2, 3, 4 and 5 years was, respectively, 90%, 88%, 84%, 79% and 78%.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

The clinical relevance of electromyopotential oversensing in current unipolar devices.

UNLABELLED: Electromyopotential oversensing of unipolar pacemakers was first appreciated 20 years ago, but its prevalence in present day devices is less well defined. Thirty-four pacemaker patients, only two with symptoms suggestive of oversensing, were evaluated in unipolar settings to assess the frequency of provocation of oversensing in one or, if present, both pacing channels. The sensing threshold of each patient, whenever possible, was recorded as well. RESULTS: Atrial oversensing occurred in 11/18 patients (61%), all at sensitivities in the 0.4-1.0 mV range. Ventricular oversensing was noted in 13/33 patients (39%), with all but one programmed to settings of 1.25 mV or more sensitive (i.e. < 1.25 mV). Twenty six of 26 patients amenable to testing had ventricular sensing thresholds of at least 4.0 mV or more. Of the 15 patients amenable to atrial sensing threshold testing, 4 had a threshold of 1.0 mV or < 1.0 mV, 6 had thresholds between 1.0-2.0 mV, and 5 sensed at settings > 2.0 mV. CONCLUSION: Electromyopotential oversensing remains a relevant issue in current day unipolar pacemakers. Most patients do not describe symptoms related to electromyopotential interference, yet such interference is frequently provoked. Oversensing is common at high sensitivities typically utilized for atrial sensing, but quite unusual at settings necessary for adequate ventricular sensing. Programming unipolar devices to unnecessarily high sensitivities should be avoided or serious consequences may result.

Cardiac Pacing, Artificial↗
PubMed1992

Removal of infected transvenous leads requiring cardiopulmonary bypass or inflow occlusion.

Infection, although uncommon, can be the most lethal of all potential complications after transvenous pacemaker implantation. The infection rate at our institution has been 0.56% (42 implants) during the preceding 17 years for 7435 transvenous pacemakers implanted in 4333 patients. Four of the 42 patients required use of cardiopulmonary bypass or inflow occlusion to remove the infected transvenous leads. Seven patients had their pacemakers implanted elsewhere and were transferred to our medical center for treatment. One patient died postoperatively because of persistent sepsis from a retained lead segment. All other patients survived, and none had recurrent infection. We recommend removal of all hardware if there is infection of the pacemaker system. If traction or other methods fail to remove the transvenous portion of the pacemaker system, open methods of removal, although rarely required, are safe and effective and should be used without delay.

Adolescent↗
PubMed1991

Pacemaker infection with Mycobacterium avium complex.

A 21-year-old. HIV negative, malnourished, homeless woman with congenital heart block had a pacemaker implanted at 7 years of age and multiple procedures thereafter. The most recent of these procedures was replacement of a pulse generator in the right pectoral region. Four months later she had fever, pain, and swelling over the implant site resulting from infection with mixed flora and Mycobacterium avium complex. The pacemaker system was removed by thoracotomy via a median sternotomy and a new DDD pacemaker simultaneously implanted. She was treated with systemic antibiotics--isoniazid, rifampin, ethambutol--for 2 weeks. Six months later she was healthy, pacing well, and apparently free of infection, off all medications.

Adult↗
PubMed1990

Clinical predictors and natural history of atrial fibrillation in patients with DDD pacemakers.

Effective DDD pacing requires that patients remain free of atrial fibrillation (AF). Four hundred eighty-nine consecutive patients undergoing initial transvenous DDD implants were reviewed to determine the incidence of postimplant AF in this population and to assess what factors, known at implant, predicted the later development of AF. The variables analyzed included age, sex, indication for implant (dominant SA or AV node disease), history of AF, atrial electrogram characteristics and pacing threshold, and the status of retrograde conduction. Forty-eight patients (9.8%) developed AF a mean of 23 months postimplant, and 11 of these patients returned to sinus rhythm and were managed once again in DDD for significant periods. A prior history of AF and the presence of dominant sinoatrial disease were far more prevalent in the patients who developed AF (P less than 0.001) though the vast majority of patients with these two independent risk factors remained in sinus rhythm through much or all of their follow-up period. We conclude that the incidence of AF is not of a magnitude to preclude DDD pacing in the vast majority of patients in sinus rhythm at implant.

Aged↗
PubMed1989

Lyme carditis: an important cause of reversible heart block.

Lyme disease is a tick-borne spirochetal infection, characterized by erythema chronicum migrans and an acute systemic illness. The disease is endemic in many parts of the north-eastern United States. Without treatment, late rheumatic, neurologic, and cardiac complications frequently occur. We report four serologically confirmed cases of Lyme carditis in previously healthy young men (mean age, 45 years) from endemic areas. Each presented with severe symptomatic atrioventricular block, three with episodes of prolonged ventricular asystole. Two had permanent pacemakers implanted (one was later removed), and another, very nearly did, before diagnosis. All four patients were treated with antibiotics, and in each case their rhythm returned to sinus, though one patient has Wenckebach second degree block with atrial pacing at 120 beats/min 16 months later. Carditis occurs in 4% to 10% of cases of Lyme disease and usually begins 3 to 6 weeks after the initial illness. It manifests as a transient myocarditis with varying degrees of atrioventricular block. The diagnosis is made primarily on clinical grounds and confirmed by serologic testing. Temporary cardiac pacing is frequently needed by patients who have severe heart block with hemodynamic instability. The evidence suggests that, in most cases, the block is at the level of the atrioventricular node. The block generally resolves completely with antibiotic treatment. Complete heart block rarely persists more than 1 week and the long-term prognosis appears to be excellent. Consideration and prompt recognition of this potentially lethal, but reversible, cause of heart block is crucial in order to avoid inappropriate permanent pacemaker implantation.

Adult↗
PubMed1989

Stage II endometrial carcinoma treated with external-beam radiotherapy, intracavitary application of cesium, and surgery.

From September 1972 to September 1987, thirty-six patients with stage II carcinoma of the endometrium were treated with external-beam radiotherapy to the pelvis, a single intracavitary application of cesium-137, and extrafascial hysterectomy with adnexectomy. Patients were followed for a median of 54.4 months. Overall 2- and 5-year actuarial survival rates were 83 and 58%, respectively. Survival was analyzed in terms of the independent variables surgical stage, presence of a gross cervical lesion, and residual disease within the myometrium or cervix. Factors contributing to patients survival were analyzed by the log-rank method. The 12 patients with a gross cervical lesion had an adverse prognosis, as compared to those without such a lesion (P less than 0.05). Seven of the twelve patients (58%) with a cervical lesion at clinical staging demonstrated persistent or recurrent disease. The presence of extrauterine disease at surgery was a major prognostic factor in patient survival (P less than 0.01). All six patients with extrauterine disease expired 2.3 to 53.0 months after hysterectomy. Two patients with persistence of disease expired 2.3 and 7.5 months after hysterectomy. Eleven patients developed recurrent disease 2.1 to 56.5 months after hysterectomy. All presented with distant metastases. Four of the thirteen patients with persistent or recurrent disease had no residual tumor within the myometrium.

Aged↗