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Biomedical subjects

L A Hoffman

Publications and source records attributed to L A Hoffman.

At least 55 records · Page 3Linked to original sources
PubMed1993

The effect of L-carnitine and soybean oil on performance and nitrogen and energy utilization by neonatal and young pigs.

A total of 64 neonatal pigs was used in an experiment to study the effect of L-carnitine and soybean oil on pig performance and N and energy utilization. Pigs were weaned at an average of 3 d of age and individually fed diets that contained dextrose, corn syrup solids, and isolated soy protein for 21 d. Two levels of soybean oil (1.18 or 12.31%) and L-carnitine (0 or 800 ppm) were used in a factorial arrangement of treatments. Diets were formulated to contain the same nutrient content per megacalorie of ME. Total fecal and urine collections were made from d 17 to 21 of the experiment. Pigs were paired within treatments on d 21 and housed in pens until d 63. L-carnitine was lowered to 750 ppm and the soybean oil additions were 1.15 or 13.22% from d 21 to 42 and 2.17 or 14.74% from d 42 to 63. Soybean meal replaced isolated soy protein from d 42 to 63. Analysis of covariance was used with calculated ME intake per day as the covariate. There were no carnitine x soybean oil interactions (P > .05) for any criteria measured. L-carnitine or soybean oil did not (P > .05) affect ADG, grams of gain per megacalorie of ME, ME as a percentage of GE or N retained as a percentage of N consumed. In conclusion, L-carnitine did not improve the utilization of ME in diets that contained high additions of soybean oil, and calories from soybean oil were utilized as effectively as calories from carbohydrate by neonatal and young pigs.

Animal Feed↗
PubMed1993

Autoimmune disease and silicone breast implants.

An association between crystalline silica and immune disease has long been recognized. However, despite ongoing case reports of systemic autoimmune disease in silicone implant recipients, the available data has not been sufficient to prove or disprove a causal relationship. Silicone has been shown to "bleed" from the implants and can migrate to distant sites. There is evidence of cellular and humoral immune responses to silicone in vivo, but the role of these responses in the development of connective tissue disorders has not been determined. Further studies are necessary to elucidate the role of silicone, if any, in the pathogenesis of autoimmune connective tissue disease. Meanwhile, the implant population needs to be closely monitored; their clinical management should be based on a case by case evaluation.

Adult↗
PubMed1992

Functional reconstruction for severe postburn microstomia.

A man with severe burn microstomia refractory to traditional management (Z release, skin grafting, splinting, bilateral commissuroplasty, and extensive physical therapy) is presented. Successful functional microstomia reconstruction was achieved with a three-stage approach consisting of the following: (1) lip, commissure, and cheek reconstruction with bilateral temporalis muscle transfers; (2) free flap neck and lower lip contracture release; and (3) vestibuloplasty with a stented full-thickness skin graft.

Adult↗
PubMed1992

Facial skeletal growth after timed soft-tissue undermining.

This study was designed to answer the following questions: (1) Does aggressive bilateral soft-tissue undermining of the nasomaxillary complex in an immature animal without an iatrogenically produced cleft lip significantly inhibit growth? (2) If so, is the early timing of this undermining crucial? Fifty New Zealand White rabbits were used in this study, and bilateral buccal sulcus incisions with extensive nasomaxillary supraperiosteal undermining were performed in the experimental groups. There were five groups: (1) control, (2) undermining at 3 to 4 days, (3) undermining at 7 to 10 days, (4) undermining at 18 to 21 days, and (5) undermining at 50 to 56 days. The animals were sacrificed at 6 months of age, and direct osteometric measurements were made. Results demonstrated that a significantly retruded, constricted, and vertically shortened maxilla was produced as a direct result of bilateral nasomaxillary soft-tissue undermining alone regardless of the timing.

Analysis of Variance↗
PubMed1992

Radiation therapy of cancer in prosthetically augmented or reconstructed breasts.

The authors review the literature and report their experience with radiation treatment of 39 prosthetically augmented or reconstructed breasts in 37 patients with primary or recurrent breast cancer. Group 1 consisted of 10 patients (12 primary breast cancers), of whom six had undergone previous breast augmentation and were later treated with lumpectomy and radiation therapy. Four patients were treated with mastectomy, reconstruction, and postoperative irradiation. Local tumor control was achieved in all patients. Excellent or good cosmetic results were achieved in all but two patients. Group 2 consisted of 27 patients with recurrent breast cancer after mastectomy and reconstruction. Local tumor control was achieved in 78% (21 of 27), with a mean duration of 34 months. Excellent or good cosmetic results were achieved in 93% (25 of 27). Patients who develop primary or recurrent breast cancer in prosthetically augmented or reconstructed breasts can be offered radical radiation therapy, with satisfactory tumor control and aesthetic results.

Adult↗
PubMed1992

Nasal cannula and transtracheal oxygen delivery. A comparison of patient response after 6 months of each technique.

The purpose of this study was to compare the efficacy of transtracheal (TT) oxygen delivery to that of nasal cannula delivery in subjects with chronic obstructive pulmonary disease (COPD). Twenty subjects (14 men, 6 women) were followed for 6 months during nasal cannula delivery. A TT catheter was then inserted, and measurements were repeated during TT use. With TT delivery, subjects required 45% less oxygen at rest and 39% less during exercise (p less than 0.0001). Oxygen use, measured by pounds of oxygen delivered to the home, also decreased, but the magnitude of change was less than anticipated (mean, 14%; range, +4% to -32%). Hospital days decreased from 12 +/- 10 during nasal cannula use to 4 +/- 6 during TT use (p less than 0.002). Exercise tolerance, as measured by a 12-min walk distance, was greater during TT use (p less than 0.0001). No change was seen in spirometry or acid-base balance. Also, no change was seen in Profile of Mood States, Sickness Impact Profile or Katz Adjustment Scale scores. Some problems were encountered relating to use of the catheter (displacement, mucus balls), but they were minor, and most were confined to the initial 2 months of TT use when the tract was immature. Our experience suggests that, in addition to decreasing oxygen flow rate, use of TT delivery may confer benefits that result in improved exercise tolerance and decreased hospitalization in patients with COPD.

Catheterization↗
PubMed1992

Anterior cervical microsurgical approach to the cranial base in the rabbit: technical note.

Current trends in research on craniofacial syndromes have led to enhanced interest in the cranial base as a contributory factor in the development of normal and abnormal midfacial structure. Indeed, attention has focused upon one particular growth plate in the posterior cranial base, the spheno-occipital synchondrosis, since it has been shown that alterations in this structure are associated with profound changes in craniofacial growth. In this report we describe a surgical approach to the cranial base of the rabbit that is safe, simple and reliable. It is applicable to neonatal as well as adult rabbits.

Animals↗
PubMed1992

The use of a short-length transtracheal oxygen catheter in patients of small stature with restrictive lung disease.

Transtracheal oxygen therapy is being used with increasing frequency because it is an effective mode of oxygen delivery and is well tolerated by patients. An increase in cough and mild intermittent hemoptysis are not uncommon in the early postinsertion period but usually resolve spontaneously. Herein we present two individuals of short stature with restrictive lung disease who had persistence of excessive cough and mild hemoptysis after insertion of a standard catheter (SCOOP). Bronchoscopic evaluation in one revealed erosions of the mucosa over the carina and take-off of the right main-stem bronchus. Symptoms resolved in both individuals following placement of a shorter catheter. We suggest that greater consideration be given to matching transtracheal catheter length to patient lung size, particularly in the face of severe restrictive lung disease.

Adult↗
PubMed1992

Effects of a closed tracheal suction system on ventilatory and cardiovascular parameters.

OBJECTIVE: To determine whether patients ventilated in the assist-control mode experienced a change in oxygenation, respiratory rate, inspiratory:expiratory ratio, heart rate, blood pressure or acid-base balance when suctioned with a closed tracheal suction system. DESIGN: A quasi-experimental, within-subject, repeated-measures design was used. SUBJECTS: 18 patients ventilated on a fraction of inspired oxygen of 0.47 +/- 0.17 and 2.3 +/- 5.0 cm H2O positive end-expiratory pressure. INTERVENTIONS: Two suction passes were performed, with measurements at baseline, immediately after the first suction pass, immediately before the second suction pass, immediately after the second suction pass, 2 minutes after the second suction pass and 5 minutes after the second suction pass. No hyperoxygenation was used. RESULTS: Significant differences were seen over time for arterial oxygen saturation, respiratory rate and inspiratory:expiratory ratio. Arterial oxygen saturation decreased to less than 90% in four subjects (range 88% to 89%), with a maximum fall of 9%. No significant differences were seen for heart rate, blood pressure, partial pressure of carbon dioxide, bicarbonate, time to nadir (lowest arterial oxygen saturation) or recovery time. CONCLUSIONS: Subjects ventilated in the assist-control mode and suctioned with a closed tracheal suction system did not experience significant changes in cardiovascular or acid-base parameters when suctioned without hyperoxygenation. Although most subjects did not become desaturated, four subjects experienced desaturation at one or more intervals. To prevent desaturation, hyperoxygenation should be used before and after suctioning with a closed tracheal suction system.

Aged↗
PubMed1992

Donor leukocyte migration following extremity transplantation in an experimental model.

In an effort to further define the immunologic mechanisms leading to acute composite-tissue allograft rejection, the migratory patterns of donor leukocytes were evaluated. Using a rat model, 52 orthotopic vascularized hindlimb transplants were performed in strains representing major histocompatibility mismatches. In order to evaluate the effect of allogeneic skin on limb rejection, all donor skin was removed in a second group of allografts. Recipient lymphoid organs were examined during the week following transplantation for antigen-presenting cells using a donor-specific class II monoclonal antibody. Donor leukocytes, with dendritic cell morphology, were identified in recipient spleen and lymph nodes draining the allograft. Significantly higher numbers of donor leukocytes were present during postoperative days 1 through 4 for both groups. Association of these important passenger leukocytes with host T-lymphocytes may represent the site of initiation of the immune response.

Animals↗
PubMed1991

Transtracheal delivery of oxygen: efficacy and safety for long-term continuous therapy.

Transtracheal (TT) oxygen delivery involves administration of oxygen percutaneously through a catheter inserted in the suprasternal trachea. Transtracheal oxygen delivery has been proposed as a means of overcoming the high visibility, inconvenience, and discomfort associated with nasal cannula use. This report describes our experience using TT delivery in 40 patients with chronic obstructive pulmonary disease (n = 32) and other types of lung disease (n = 8). Overall acceptance of TT catheter use was high and only 5 subjects elected to discontinue use. We believe the TT route is a relatively safe approach for oxygen administration and a promising method of improving patient compliance. It also offers the potential of more adequately oxygenating patients with refractory hypoxemia.

Adult↗
PubMed1990

One-stage repair of the anterior abdominal wall using bilateral rectus femoris myocutaneous flaps.

Total lower abdominal wall resection was required to remove a recurrent exophytic bladder carcinoma in a 36-year-old woman. The resulting 25 x 30-cm fascial defect was repaired with Marlex mesh. Bilateral rectus femoris myocutaneous flaps were rotated to close the 25 x 18-cm area of skin deficiency. These provided the advantages of robust cover of the lower abdominal wall in a single-stage procedure and primary closure of the donor sites.

Abdominal Muscles↗