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Biomedical subjects

M M Lane

Publications and source records attributed to M M Lane.

At least 37 records · Page 2Linked to original sources
PubMed1994

Medium-term follow-up of pulmonary autograft replacement of aortic valves in children.

Pulmonary autograft replacement (PAG) of the aortic valve in children has been shown to be safe and effective with a low incidence of late valve dysfunction. Relief of all types of left ventricular outflow tract obstruction using the pulmonary root has been possible. Concern about the durability of the pulmonary root in the aortic position, and the potential for growth of the pulmonary autograft used either as a root replacement or intraaortic implant, has been questioned. Sixty-five consecutive patients, aged 1.8 to 21 years (mean 12 years) operated on between September 1986 and January 1993, 35 with an intra-aortic implant (IA) and 30 with root replacement (RR), were evaluated by clinical and serial echocardiographic studies (ECHO) up to 6.5 years post-operatively. The hospital mortality rate was 3.0% (70% CL 2.1-5.1%). Two patients required reoperation for PAG insufficiency (AI), one for technical malalignment necessitating replacement at 6 months, and one with progressive leaflet prolapse due to adherence of the valve leaflet to a ventricular septal defect (VSD) patch. Freedom from significant aortic regurgitation at 6-year follow-up was 100% for RR and 91 +/- 6% for IA, and freedom from all valve-related complications including reoperation was 92 +/- 5% at 6 years. Significant enlargement of the aortic annulus which parallels somatic growth has been measured by ECHO in 17 IA implants (P < 0.001) and 17 RR patients (P < 0.01) by 1 year, and in 10 IA (P = 0.007) and 6 RR (P < 0.05) by 2 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Pulmonary autograft replacement of the aortic valve in the potential parent.

Aortic valve replacement in the child and young adult is often delayed, and multiple operations or invasive procedures are performed to avoid valve replacements. Prosthetic valves, bioprosthetic valves, or allograft valves have been associated with significant complications or early failure and have been a disappointing solution for the patient requiring aortic valve replacement. The pulmonary autograft replacement (PAR) of the aortic valve in children has been shown to be safe and effective with a low incidence of late valve dysfunction. The absence of thromboembolism, the avoidance of anticoagulants, and its viability with the potential for growth and repair strongly support its use for the potential parent, patients of age 35 or less. The experience with 112 patients, 32 females and 80 males, ages 1.5 to 35 years (average 16.1) are reviewed. Twenty-four had aortic insufficiency, 34 had aortic stenosis, and 54 had both aortic stenosis and insufficiency. Actuarial survival was 95.4% +/- 2.0% at 7 years and freedom from reoperation or significant aortic insufficiency of the autograft valve was 92.7% +/- 3.7%. Freedom from all valve related complications of the autograft valve and the homograft replacement of the pulmonary valve was 90.0% +/- 4.0%. Reoperation for the autograft valve was related to limited experience in one, leaflet prolapse and adherence to a VSD patch in one, associated lupus erythematosus in one, and annular and sinotubular dilatation in one. Reoperation of the homograft valve in two patients was secondary to early homograft stenosis, probably due to rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1993

Neonatal coarctation repair. Influence of technique on late results.

BACKGROUND: Coarctation repair in the neonate (< or = 28 days) is associated with higher mortality and increased incidence of restenosis compared with older infants. It has been suggested that resection of pericoarctation ductal tissue may reduce this risk of restenosis. METHODS AND RESULTS: To further clarify these issues, we reviewed our experience with 111 consecutive neonates undergoing primary repair between 1973 and 1991. Hospital mortality was 14.4% (16 of 111) and was not significantly different for the type of repair:resection and end-to-end anastomosis (RETE) 10.7% (6 of 56), subclavian flap angioplasty (SFA) 16.7% (6 of 36), and patch angioplasty (PA) 16.7% (3 of 18). Associated complex cardiac pathology was associated with higher operative risk: 25% (10 of 40) versus 8.4% (6 of 71) (P = .02). Median follow-up of 4.2 years (range, 0.1 to 18.5 years) was 99% complete. Late mortality was 13.6% (13 of 95), of which 92% occurred within 1 year of repair. Twenty percent (19 of 95) needed reintervention for restenosis, RETE 16% (8 of 50), SFA 13% (4 of 30), and PA 47% (7 of 15) (P = .02). Of these, 84.2% (16 of 19) required reintervention within 1 year of repair. Freedom from reintervention 1 and 8 years after operation was 80 +/- 4% and 77 +/- 5%, respectively. Actuarial survival 8 years after operation was 73 +/- 4%; for simple coarctation, this was 90 +/- 4%. By multivariate analysis, survival was negatively influenced only by presence of associated cardiac pathology (P = .002) and reintervention only by patch angioplasty technique of repair (P = .007). CONCLUSIONS: In the neonate, resection of coarctation (RETE) does not diminish the risk for reintervention compared with SFA. The risk for both late death and recurrent coarctation are highest within the first year after repair, and follow-up should be particularly vigilant during this period.

Actuarial Analysis↗
PubMed1990

Early detection of colorectal cancer by quantitative fluorescence image analysis of exfoliated cells.

Early-stage colorectal cancer is potentially curable. In the present study, we applied quantitative fluorescence image analysis (QFIA) cytology to the detection of experimental colorectal cancer in a rodent model. QFIA cytology combines visual cytologic examination with quantitation of DNA content in single exfoliated cells. Cancer was induced by treating 110 rats with subcutaneous 1,2-dimethylhydrazine. Sequential colon washes were obtained weekly from each animal for 20 weeks. Control animals were treated identically except for the administration of carcinogen. Cells that were cytologically abnormal or had increased DNA content were found starting in the second week. By the eighth week, roughly 50 percent of animals had positive results, and this level remained approximately constant for the duration of the study. Tissue pathologic results were normal during weeks 1 to 7. Dysplasias became common during weeks 8 to 15 whereas most cancers appeared during weeks 16 to 21. These results indicate that QFIA cytology is a highly sensitive method for detecting even preneoplastic changes resulting from carcinogen administration and may prove useful in detecting human colorectal cancer.

Animals↗
PubMed1986

Effects of prior administration of steroids upon recovery from lethal sepsis.

The effects upon survival of large doses of steroid administered to dogs prior to challenging them with lethal sepsis was evaluated in this study. Dogs were given 30 milligrams per kilogram of body weight per day of methylprednisolone sodium succinate for one, two or eight days and then were infused with 9.72 +/- 0.35 X 10(9) Escherichia coli per kilogram of body weight. All dogs in group 1 (n equals six) not given steroid died within 25 hours. Of the dogs in group 2 (n equals 12) given one or two doses of steroid previously, 42 per cent permanently survived (more than seven days). All dogs in group 3 (n equals five) given eight daily doses of steroid prior to infusion of Escherichia coli died within 17 hours. Dogs in group 4 (n equals six) were given eight daily doses of steroid prior to infusion of Escherichia coli and treated on the day of infusion of Escherichia coli with a regimen of methylprednisolone and gentamicin sulfate which results in a 100 per cent survival rate when given to dogs that have not received prior treatment with steroid. Thirty-three per cent of the dogs in group 4 permanently survived. One or two daily large doses of steroid did not detrimentally affect survival of the dogs. Eight days of steroid administration suppressed endogenous cortisol production. When the dogs were treated with six hours of steroid-antibiotic therapy, survival benefits were limited.

Adrenal Cortex Hormones↗
PubMed1985

Reoperation in congenital aortic stenosis.

Over a 22-year period, 81 patients underwent initial operations for critical aortic stenosis at our institution. Their ages ranged from 3 days to 20 years (mean, 7.3 +/- 5.9 years). Fourteen (17%) were infants less than 1 year old. Three children died perioperatively (3.7%). We have followed the survivors and 3 children who underwent initial operations elsewhere for a mean of 9.0 +/- 6.8 years (range, 2 to 23 years). To the present, 27 patients have undergone one reoperation (24 of our initial survivors) at a mean interval of 7.3 years, with 2 perioperative deaths. Ten of these patients have required a second reoperation at a mean interval of 3.7 years, with 2 deaths perioperatively. There were 3 late cardiac deaths after the initial procedure and 1 after a third operation. Actuarial reoperation-free survival is 56.7% at 10 years. While overall survival is 88.6% at 10 years, we find a significantly poorer survival among those patients with valvular stenosis compared with those with subvalvular lesions (p = 0.03). We believe that for children with all levels of aortic stenosis, good functional results and survival can best be obtained by follow-up, recatheterization, and reoperation.

Actuarial Analysis↗
PubMed1985

Trends in bacterial susceptibility to antimicrobial agents.

Concern over the development of drug resistance by common pathogens has grown over recent years. In order to discover and describe possible trends at this institution, susceptibility data for 18 organisms and 21 antimicrobial agents for the years 1975 through 1982 at the Veterans Administration Medical Center in Oklahoma City were reviewed. Summaries of susceptibility data for 64 major combinations of drugs and organisms are presented. Two gram-positive organisms (enterococcus group D and Staphylococcus aureus) as well as a gram-negative (Pseudomonas aeruginosa) appear to be decreasing in susceptibility to several drugs. However, some gram-negative bacilli (Proteus, Serratia, and Enterobacter spp. and Klebsiella pneumoniae) showed evidence of markedly increasing susceptibility to certain drugs.

Anti-Bacterial Agents↗
PubMed1985

Senning repair for transposition of the great arteries in the first week of life.

Infants with D-loop transposition of the great arteries (D-TGA) may have unacceptable results after the balloon septostomy while awaiting surgery. It has been our policy to repair defects in infants with D-TGA and intact ventricular septum or small ventricular septal defect at the time of diagnosis. We report our experience with the Senning operation in 18 newborns less than 1 week of age. The mean age at operation was 3 days (range 12 hr to 7 days) and the mean weight was 3.5 kg (range 2.8 to 4.8). There were two early postoperative deaths (11%) and one late death (5%). Early mortality was associated with preoperative acidosis and congestive heart failure. Late mortality was associated with severe left ventricular outflow tract obstruction (LVOTO). The 15 long-term survivors have been followed for an average of 27 months and 11 of the 16 perioperative survivors have undergone postoperative catheterizations. There was no evidence of systemic or pulmonary venous obstruction. One patient developed LVOTO that led to his death. Two patients had residual atrial shunts. Electrocardiograms revealed no major arrhythmias. All patients are clinically asymptomatic. Good hemodynamic, electrocardiographic, and clinical results can be obtained with correction of D-TGA in the first week of life.

Arteries↗
PubMed1983

Preventing versus delaying death in shock therapy studies: evaluating "survival".

When results from a short-term experimental study of septic shock indicate that a therapy increases survival time (i.e., delays death), should the reader conclude that the therapy ultimately will increase the percentage of permanent survivors (i.e., prevent death)? If not, how long must animals be observed after lethal sepsis to reasonably validate that a therapy can be used to effect complete recovery? To help answer these questions, we reevaluated survival data from the symposium that entailed the largest number of separate shock therapy studies ever performed on a homogeneous group of dogs in one place at one time with a single lot of endotoxin. Twenty-eight scientists studied the responses of 115 treated and 38 untreated dogs given LD80 endotoxin by bolus injection to compare 15 therapies (most previously reported to have "increased survival"): the numbers of dogs alive were recorded at 0, 0.5, 1, 2, 4, and 7 days. Chi-square analysis indicated significantly more treated than untreated dogs alive only at 24 hr and significantly fewer treated dogs alive on day 7 than on day 2. Individual comparison of the proportion of animals alive in each of the 15 treated groups with the untreated group showed more dogs alive (P less than 0.05) in 3 treated groups at day 1 and in 1 treated group at day 2 and 4; so, four therapies appeared to "increase survival." However, by day 7 no therapy group had statistically more survivors than the untreated group. This evaluation indicates that in order to make a clear distinction between increasing survival time and increasing the percentage of permanent survivors, both treated and untreated dogs should be observed and compared after septic challenge until the percentage of survivors in both groups attains a steady state.

Animals↗
PubMed1976

Renal gluconeogenesis and increased glucose utilization in shock.

The roles of renal gluconeogenesis and glucose utilization in control, hemorrhaged, and endotoxin-injected animals were investigated using anesthetized, eviscerated, nonnephrectomized and nephrectomized dogs. Results demonstrate an increased glucose utilization in both hemorrhagic and endotoxic shock which was marked after endotoxin. Since blood glucose values dropped more in nephrectomized, hemorrhaged animals, in contrast to the nonnephrectomized, hemorrhaged dogs, the kidneys were assumed to perform a significant gluconeogenic role. The kidneys did not appear to perform gluconeogenesis in endotoxin shock since blood glucose levels were comparable in eviscerated, endotoxin-treated animals whether nephrectomized or not. To ascertain the tissue responsible for the increased glucose utilization in endotoxin shock, a study was performed with endotoxin added to blood in vitro (estimated LD100 concentration). The endotoxin-treated blood (n = 7) demonstrated an increased glucose utilization compared with saline controls (n = 7) (P less than or equal 0.02). Acclerated glucose utilization rates were comparable between the eviscerated, nephrectomized animals and in vitro experiments. These data suggest that excessive glucose demand by certain blood components may partially explain the lethal hypoglycemia of endotoxin shock.

Animals↗