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Biomedical subjects

C R Smith

Publications and source records attributed to C R Smith.

At least 127 records · Page 7Linked to original sources
PubMed1994

Tracheoplasty without stent, using preshaped cryopreserved cartilage allografts in neonatal pigs.

The management of congenital and acquired laryngotracheal stenosis in children often includes tracheoplasty with different materials. Autologous cartilage is the most commonly described graft for tracheal reconstruction. In 12 1-week old piglets a tracheal defect was created and repaired using cryopreserved allografts sculpted before preservation into a newly designed shape. In half the animals (group 1), a free pericardial autograft was interposed on the luminal surface of the cartilage graft. A stent was not used in any animal. The animals grew normally and were killed after 2 months. The grafted tracheas showed maintenance of their structural support, and no evidence of narrowing of the grafted area in comparison to the trachea above the graft. The lumen was lined by ciliated respiratory epithelium. There was no identifiable pericardium at the time of sacrifice and no differences between the two groups. This study shows that in neonatal pigs, cartilage allografts, sculpted before cryopreservation, are a suitable alternative to autografts to cover tracheal defects and can be used without stenting. No advantages were identified when interposing a free pericardial graft.

Animals↗
PubMed1994

Serological surveillance of plague in dogs and cats, California, 1979-1991.

Following natural infection both cats and dogs develop antibodies to plague which can be measured for several months after infection. Besides being helpful in the diagnosis of plague in domestic carnivores, the antibody titer has important implications in outbreak investigation and surveillance programs. We report the first serological survey for plague in domestic carnivores conducted in California between 1979 and 1991 in five different settings or programs. A total of 4115 dogs and 466 cats were tested for plague antibody by the passive hemagglutination test. 86 dogs (2.09%) and 15 cats (3.22%) had plague antibody titers > or = 1:16. The percentage of positive dogs and cats were respectively 3.96% and 0% on reservations, 3.27% and 1.39% on military bases, 0.74% and 1.25% in Los Angeles County and 0% and 4.61% in veterinary clinics, but 41.38% and 41.2% from outbreak investigations. Titers ranged from 1:16 to 1:4096 in dogs and cats, but were low in dogs and cats in the Los Angeles County survey and on the military bases. Serologic testing of pets during human case investigation or increased rodent mortality should be regularly implemented, as well as dog surveys on reservations. Surveys of pet dogs in veterinary clinics did not appear worthwhile, even if selected from plague endemic regions. Veterinarians should report suspect cases in cats to public health authorities, that will improve plague surveillance and reduce the risk of humans contracting the disease from their pets.

Animals↗
PubMed1994

Incidence of pulmonary vein complications after lung transplantation: a prospective transesophageal echocardiographic study.

OBJECTIVES: This study attempted to document the incidence of pulmonary vein complications and their potential relation to clinical outcome in patients after lung transplantation. BACKGROUND: Several case reports have documented the presence of pulmonary venous thrombosis causing graft failure in patients after lung transplantation. Because the presentation of these complications mimics that of other postoperative problems, the true incidence of pulmonary vein abnormalities remains unclear. Transesophageal echocardiography is ideally suited to examine the pulmonary veins in the postoperative setting. METHODS: Twenty-one consecutive patients undergoing lung transplantation at our institution underwent transesophageal echocardiography within 32 days of transplantation (mean [+/- SD] 6.5 +/- 7.8 days). Special attention was placed on visualizing the pulmonary veins. RESULTS: Six (29%) of the 21 patients were noted to have abnormalities of the pulmonary veins in the vicinity of the anastomotic site. After follow-up of 30 days, 4 of these patients (67%) had significant cardiovascular morbidity, and 2 died, compared with 1 (7%) of 15 patients with normal pulmonary veins (p = 0.03). The degree of obstruction of the pulmonary vein appeared to correlate with short-term outcome. CONCLUSIONS: Abnormalities of the pulmonary veins are common after lung transplantation and are easily identified by transesophageal echocardiography. Occlusive thrombi appear to be detrimental to short-term outcome.

Adult↗
PubMed1994

The role of retroperitoneal lymphadenectomy in localized paratesticular rhabdomyosarcoma.

Between 1985 and 1990, 10 cases of embryonal paratesticular rhabdomyosarcoma were treated at our institution. Patient age ranged from 5 months to 16 years at presentation (mean 8.7 years). Chest and abdominal computerized tomography (CT) was performed on all patients. Lymphangiography was performed on 2 patients, and 6 underwent retroperitoneal lymphadenectomy, due to suspicious CT (2) and a positive lymphangiogram (1). All 6 patients had pathologically negative nodes, and they received vincristine, actinomycin D and cyclophosphamide for 8 to 13 months (mean 10.6 months). Four patients also received doxorubicin. The 10 patients are alive and the disease is in complete remission for a mean 6.02-year disease-free survival. These data support the hypothesis that retroperitoneal lymphadenectomy can be avoided for paratesticular rhabdomyosarcoma after radical inguinal orchiectomy when CT is negative for nodal involvement.

Adolescent↗
PubMed1994

Single-stage management of 74 consecutive sternal wound complications with pectoralis major myocutaneous advancement flaps.

The optimal management of sternal wound complications remains controversial. Since 1985, we have utilized a combination of immediate, aggressive debridement with simultaneous repair using bilateral pectoralis major myocutaneous advancement flaps, regardless of the degree of infection. As compared with the use of distant pedicled muscle flaps or pectoralis major turnover flaps, the management of complicated sternal wounds with immediate pectoralis major myocutaneous advancement flaps provides an effective yet simpler, quicker method of management with improved aesthetic results. In addition, basing the pectoralis major myocutaneous flaps on the thoracoacromial arteries eliminates the need for intact internal mammary arteries, valuable since the latter are increasingly used for coronary grafts. Seventy-four consecutive patients, 17 (23 percent) of whom were immunosuppressed heart transplant recipients, have been managed with this procedure. There were no intraoperative deaths. The 30-day perioperative mortality rate was 9 percent (7 of 74), with only 1 death related to persistent sepsis. The morbidity rate was 39 percent, with the most common complication being seroma managed by needle aspiration (18 of 74, 24 percent). The aesthetic and functional results have been uniformly excellent.

Humans↗
PubMed1994

A review of laboratory techniques and their use in the diagnosis of Leptospira interrogans serovar hardjo infection in cattle.

This paper reviews the laboratory diagnosis of Leptospira hardjo infection in cattle. Two genotypes of L hardjo, Hardjoprajitno and Hardjobovis, have been identified in cattle, but only Hardjobovis has been isolated in Australia. There are problems with diagnosis and control of bovine leptospirosis. Infection is usually subclinical and the serological titres vary greatly in peak and duration. Leptospires may be excreted in urine for up to 18 months. Low microscopic agglutination test titres may be significant in unvaccinated herds as indicators of endemic infection. Vaccines differ in their composition, and their efficacy is difficult to evaluate. The serological response after vaccination is difficult to differentiate from the response after infection. Pregnant cows that become infected may abort, but this is usually after the serological response has peaked. Therefore, paired serum samples are of little use in diagnosing abortion caused by L hardjo. Fluorescent antibody techniques are more sensitive than dark field microscopy for detection of leptospires in urine and tissue samples. Techniques for culture have improved but are still difficult to perform and take 3 months or longer for results to be known. DNA probes and polymerase chain reaction tests are very sensitive and specific, quick to perform, and can be used on fluid and tissue samples.

Agglutination Tests↗
PubMed1994

Anti-myeloperoxidase antibodies in patients with rheumatoid arthritis: prevalence, clinical correlates, and IgG subclass.

OBJECTIVES: To determine the prevalence and clinical associations of autoantibodies to myeloperoxidase (MPO) in an unselected series of well-characterised outpatients with rheumatoid arthritis (RA) and to compare the distribution of IgG subclasses of anti-MPO antibodies in these patients with that in patients with systemic vasculitis. PATIENTS AND METHODS: A study was made of 97 patients with RA, who have been seen regularly in this department for up to 20 years, and 29 patients with anti-neutrophil cytoplasmic antibody (ANCA) positive systemic vasculitis. Anti-MPO antibodies were detected using a direct-binding enzyme-linked immunosorbent assay (ELISA) with MPO from human granulocytes as antigen. The IgG subclass of anti-MPO antibodies was determined by ELISA using isotype specific monoclonal antibodies. RESULTS: Anti-MPO antibodies were detected in 12% of patients with RA. Six sera contained IgG anti-MPO antibodies only, 1 IgM only and 5 antibodies of both classes. In the patients with RA the predominant subclasses were IgG1 and IgG3: only 2 sera contained detectable IgG4 antibodies. This was in contrast to patients with vasculitis, in whom most sera contained IgG1, IgG3 and IgG4 anti-MPO antibodies. Anti-MPO antibodies in sera from both patient groups bound only to the native protein. None of the patients studied with RA had evidence of vasculitis affecting the nerves or kidney: three patients (1 positive for anti-MPO antibodies and 2 negative) had cutaneous vasculitis. In the patients with RA, positivity for anti-MPO antibodies was associated with nodules and number of active joints. Three patients with anti-MPO antibodies, and none without, had pulmonary fibrosis. CONCLUSIONS: Twelve per cent of a group of unselected outpatients with RA, but without evidence of major systemic vasculitis, had anti-MPO antibodies in their serum. Positivity for anti-MPO antibodies was more common in patients with nodular disease and lung involvement but not in patients with cutaneous vasculitis. IgG4 sub-class anti-MPO antibodies were present in 90% of sera from patients with ANCA-positive vasculitis and only 2/11 (18%) of anti-MPO antibody containing sera from patients with RA.

Adult↗
PubMed1994

See-saw nystagmus in a patient with clinically definite MS.

See-saw nystagmus (SSN) is a relatively uncommon oculomotor disorder, most often associated with parasellar or chiasmal lesions, although it has also been described in several other conditions. To date, SSN has not been reported in clinically definite multiple sclerosis (MS). We present a patient with clinically definite MS who subsequently developed SSN. Possible mechanisms of SSN are discussed. MS should be considered in the differential diagnosis of SSN.

Adult↗
PubMed1993

Clinical variability within Brachmann-de Lange syndrome: a proposed classification system.

Seven patients, including two sibs, with the Brachmann-de Lange syndrome (BDLS) are presented as representative of the different types of BDLS in a proposed classification system. Type I ("classic") patients have the characteristic facial and skeletal changes of BDLS using the criteria in the diagnostic index of Preus and Rex. Type I is distinguished from the other subtypes by prenatal growth deficiency (< 2.5 S.D. below mean for gestation) becoming more severe postnatally (< 3.5 S.D. below the mean), moderate to profound psychomotor retardation, and major malformations which result in severe disability or death. Type II ("mild") BDLS patients have similar facial and minor skeletal abnormalities to those seen in type I; however, these changes may develop with time or may be partially expressed. Patients with type II BDLS are distinguished from those with other types by mild to borderline psychomotor retardation, less severe pre- and postnatal growth deficiency, and the absence of (or loss severe) major malformations. Behavioral problems can be a significant clinical problem in type II BDLS. Type III ("phenocopies") BDLS includes patients who have phenotypic manifestations of BDLS which are causally related to chromosomal aneuploidies or teratogenic exposures.

Adolescent↗
PubMed1993

Posttransplantation lymphoproliferative disorders treated with cyclophosphamide-doxorubicin-vincristine-prednisone chemotherapy.

BACKGROUND: Posttransplantation lymphoproliferative disorders after solid organ transplantation are a serious complication occurring in 1-10% of patients. Different therapies have been used, but the optimal treatment is unknown. There is relatively little information in the literature on the experience with cytotoxic chemotherapy. METHODS: The disease stage of patients with biopsy-documented posttransplantation lymphoproliferative was determined with standard methods to establish the extent of the disease. Patients in whom the disease failed to regress after initial management, which included reduction in immunosuppression, were treated with a combination chemotherapy regimen consisting of six cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Response to therapy was determined by following previously defined sites of disease with appropriate tests. Patients were maintained on a reduced dose of immunosuppressants. RESULTS: In the four patients studied, lymphoproliferative disorders developed after heart (three cases) or lung (one case) transplantation, which did not regress after immunosuppression was reduced. All four experienced a complete remission with CHOP chemotherapy, which continued at 3, 13+, 20 and 30+ months after completion of treatment. One patient died of sepsis after completing therapy at a point when his leukocyte count was normal, and no evidence of posttransplantation lymphoproliferative disorder was found at autopsy. A second patient died of liver failure with no clinical evidence of lymphoproliferative disorder. CONCLUSION: Although this is a small series, it demonstrates that patients with posttransplantation lymphoproliferative disorders may respond to cytotoxic chemotherapy. The duration of response is undetermined.

Adult↗
PubMed1993

Metastatic choriocarcinoma in an infant: imaging appearance.

Metastatic choriocarcinoma is unusual in infancy and considered to be due to metastases from the placenta. Only fifteen cases have been previously reported. We present an unusual case of hepatic, pulmonary, and axillary lymph node metastases from choriocarcinoma in a 3-month-old female. Several of the lesions had large vascular channels identified by computed tomography and sonography with color and duplex Doppler.

Choriocarcinoma↗
PubMed1993

Prevention of acute regional ischemia with endocardial laser channels.

Laser myocardial revascularization has been shown to reduce mortality and infarct size after left anterior descending coronary artery (LAD) ligation in dogs. It has not been shown to improve myocardial contractility in acute ischemia. In this study a holmium-yttrium-aluminum garnet laser (wavelength, 2.14 microns) was used to create nontransmural myocardial channels from the endocardial surface in the ischemic regions of the canine left ventricle. Twelve mongrel dogs (6 controls, 6 laser myocardial revascularizations) underwent 90 minutes of LAD ligation followed by 6 hours of reperfusion. The ischemic region was determined by methylene blue injection during brief LAD occlusion. Laser myocardial revascularization averaged three channels per square centimeter in the ischemic region created using 12 J/channel (600 mJ/pulse, 10 Hz) before LAD ligation. Contractility was assessed from regional preload recruitable stroke work (RPRSW), using pairs of segment length ultrasonic transducers in the ischemic and the nonischemic regions. Two-dimensional echocardiography corroborated with segmental length findings. In control dogs, the ischemic region was dyskinetic during LAD ligation and reperfusion. Dyskinesis of the ischemic region during systole produced negative values for regional stroke work, and RPRSW was considered zero. In 4 of 6 laser-revascularized dogs, RPRSW remained positive in the ischemic region. Two dogs had intermittent dyskinesis. The difference between laser-revascularized and control dogs in ischemic region RPRSW was significant (p < 0.01 by Fischer's exact test).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗