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K J Welch

Publications and source records attributed to K J Welch.

At least 19 recordsLinked to original sources
PubMed1991

False-positive results in serologic tests for Rocky Mountain spotted fever during pregnancy.

The data from this study demonstrate that false-positive results from tests for Rocky Mountain spotted fever increase with the duration of pregnancy. The sera of 4.0% (2/50) of women in their first trimester of pregnancy, 10.9% (5/46) in their second trimester, and 12.1% (12/99) in their third trimester yielded false-positive results from latex agglutination assays for Rickettsia rickettsii infections. The cause of these false-positive results was not determined by this study. These false-positive titers were not associated with clinical findings or other laboratory abnormalities. Even though these sera did not contain antibodies to R rickettsii detectable by indirect fluorescent antibody testing, such false-positive results from serologic tests for Rocky Mountain spotted fever can obscure the patient's correct diagnosis. This may lead to the unnecessary use of potentially toxic antibodies and prevent initiation of appropriate therapy.

Adolescent↗
PubMed1990

Thioureas react with superoxide radicals to yield a sulfhydryl compound. Explanation for protective effect against paraquat.

Thiourea and superoxide dismutase were effective antidotes to paraquat toxicity in an HL60 cell culture system, whereas other hydroxyl scavengers were ineffective. The efficacy of thioureas was not due to blockage of intracellular paraquat uptake, inhibition of NADPH-P-450 reductase, or reaction with the paraquat radical. Thiourea also competitively inhibited the reduction of cytochrome c by the xanthine/xanthine oxidase superoxide-generating system, and the release of iron from ferritin by superoxide radicals. The reaction of superoxide with thiourea produced a sulfhydryl compound distinct from products formed by hydrogen peroxide or hydroxyl radicals. Spectrophotometric and chromatographic studies indicated the carbon-sulfide double bond was converted to a sulfhydryl group which reacted with Ellman's reagent. Additional confirmatory evidence for the sulfhydryl compound was obtained with carbon-13 NMR and mass spectroscopies. Thus, thioureas are direct scavengers of superoxide radicals as well as hydroxyl radicals and hydrogen peroxide. The rate constant for the reduction of thiourea by superoxide was estimated at 1.1 x 10(3) M-1 s-1. The implication of this finding on free radical studies, the mechanism of paraquat toxicity, and the metabolism of thioureas is discussed.

Acetonitriles↗
PubMed1989

Surgical treatment of thoracic deformity in Poland's syndrome.

In 1841, Poland described congenital deficiency of the pectoralis major and minor muscles associated with syndactyly. This syndrome is a spectrum, often involving chest wall and breast deformity as well. Identification of the various musculoskeletal components involved permits optimal thoracic reconstruction in the small proportion of patients who will require it. From 1955 to 1988, 75 patients (40 males and 35 females) with Poland's syndrome were treated or evaluated. Patients with isolated deficiencies of the pectoral muscles, breast, or hand deformity were excluded. The complex was right-sided in 44 patients, left-sided in 30, and bilateral in one. The pectoralis minor and the costal portion of the pectoralis major muscle were absent in all patients. Hand anomalies were present in 50 patients. Athelia and/or amastia were noted in 37 patients. In ten patients, the rib cage deformity required reconstruction, and in three cases, rib or cartilage grafts were needed for complete repair. Often unappreciated in these cases is the significant rotation of the sternum toward the involved side and contralateral carinate deformity. Correction is achieved by bilateral subperichondrial costal cartilage resection and sternal osteotomy (seven of ten patients), thus allowing anterior displacement and orthorotation of the sternum. Chest wall reconstruction must be tailored to the requirements of each patient. No intraoperative or postoperative complications occurred in these ten patients. In males without rib cage deformity, generally no treatment is required to replace the absent pectoral muscles, although in two cases rotation of the latissimus dorsi muscle was performed. In all females, reconstruction of the ipsilateral breast is required at full development.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗
PubMed1988

Surgical correction of chondromanubrial deformity (Currarino Silverman syndrome).

Chondromanubrial (arcuate) pectus carinatum is the rarest protrusion deformity of the chest. Its surgical correction was first described by Ravitch in 1952. We have recently encountered five patients with this deformity who have provided additional insight into the anatomy and optimal repair of this condition. It is notable for a short nonsegmented sternum with marked posterior angulation at the site of the normal chondromanubrial junction. It is optimally corrected by subperichondrial resection of the second to the seventh costal cartilages with a broad wedge-shaped osteotomy through the anterior cortex of the sternum at the point of maximal angulation. Anterior displacement of the sternum is achieved by closing the osteotomy with heavy silk sutures while the costal cartilages are regenerating.

Adolescent↗
PubMed1988

Surgical repair of pectus excavatum.

From 1958 to March 1987 we corrected 704 patients with pectus excavatum. The condition occurred more frequently in boys (544 patients) than girls (160 patients). In the majority of patients (86%), the defect was evident at birth or within the first year of life. Musculoskeletal abnormalities were identified in 133 patients (scoliosis, 107; kyphosis, 4; myopathy, 3; Poland's syndrome, 3; Marfan's syndrome, 2; Pierre Robin syndrome, 2; prune belly syndrome, 2; neurofibromatosis, 3; cerebral palsy, 4; tuberous sclerosis, 1; and congenital diaphragmatic hernia, 2). Sixteen patients had associated congenital heart disease. A family history of chest wall deformity was present in 37% of the cases and a history of scoliosis in 11%. Surgical correction was performed using a uniform technique for bilateral subperichondrial resection of the deformed costal cartilages and sternal osteotomy resecting a wedge of the anterior cortex and fracturing the posterior cortex. Anterior displacement was maintained with silk sutures closing the osteotomy defect. In 28 early cases, the sternum was secured by intramedullary fixation with a Steinman pin. All repairs were completed with a low complication rate (4.4%; pneumothorax, 11; wound infection, 5; wound hematoma, 3; wound dehiscence, 5; pneumonia, 3; seroma, 1; hemoptysis, 1; hemopericardium, 1). Six complications were associated with Steinman pin fixation (hemoptysis, seroma, hemopericardium, pneumothorax, 3). Major recurrence occurred in 17 patients (2.7%) and led to revision in 12. Satisfactory long-term results were achieved in the remaining 687 patients, with follow-up ranging from 2 weeks to 27 years. Mean follow-up was 4.3 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Cardiopulmonary function in pectus excavatum.

The results of recent studies clearly support a cardiopulmonary impairment resulting from pectus excavatum, but resolving the apparent discrepancies between studies is necessary. Several factors must be taken into consideration. The severity of the deformity of the chest wall must be defined, whether by the sternovertebral distance or by various means proposed by others. Without some index of the degree of sternal depression, it is impossible to compare patients or results among studies. No study has enrolled a sufficient number of patients to provide an accurate correlation between the severity of the deformity and the extent of the cardiopulmonary deficit, nor has any defined how severe the deformity must be to result in cardiopulmonary dysfunction. The second factor that is important in evaluating results is what controls were used. Studies in which each patient functioned as his own control after surgical repair are preferable. In the pediatric age group where growth and increased pulmonary parameters would be expected, the follow-up studies should be performed at a defined time after surgical treatment. Studies completed years later cannot assess the effect of surgical repair upon cardiopulmonary function. Studies wherein persons matched for age and height to serve as controls are available from the same laboratory are also needed. The degree of co-operation and effort of patients will vary, particularly in the pediatric age group. Constancy of the experimental protocol and personnel is important. Least reliable are reports of experimental findings compared with standardized normal values. In early studies, measurements of vital capacity and total lung capacity produced variable results when compared with normal persons matched for age. The wide range of "normal values" makes statistical comparison difficult, if not impossible. A wide spectrum of cardiopulmonary function exists among individuals, depending upon prior physical training and body habitus. Sufficient physiologic reserve is generally present, such that extensive impairment must exist before patients become symptomatic at rest. Physiologic reserve during exercise is rapidly consumed and differences can be more readily determined. Exercise studies must go beyond the measurement of intracardiac pressures and pulmonary volumes at rest.(ABSTRACT TRUNCATED AT 250 WORDS)

Funnel Chest↗
PubMed1988

Anterior chest wall deformities and congenital heart disease.

Pectus excavatum and pectus carinatum usually exist as isolated abnormalities. Only 19 cases of associated congenital heart defects have been reported. Significant complications related to uncorrected pectus excavatum have been described either during or after cardiac operations. Therefore we reviewed our experience with these coexisting lesions to assess the risk of surgical repair of chest wall deformities before and after correction of congenital cardiac anomalies. Among 20,860 infants and children with congenital heart disease seen at our institution, 36 (0.17%) had associated anterior thoracic deformities, 22 of whom underwent surgical correction of pectus excavatum or pectus carinatum. Ten of these 22 patients had pectus repair after a cardiac operation. Pleural or pericardial entry was avoided in all and none required a blood transfusion. Ten other patients had pectus repair either before cardiac repair (five patients) or without a subsequent cardiac operation. Another patient had a cardiac operation performed through a median sternotomy both before and after pectus repair, and the remaining patient, early in the series, had simultaneous banding of the main pulmonary artery and repair of pectus excavatum complicated by chest wall instability and a lethal intrathoracic hemorrhage. The experience indicates that congenital chest wall deformities can be safely and effectively repaired after early correction of congenital heart defects through a median sternotomy, although repair of the chest wall deformity after cardiac surgery also gives good results. However, in children who require an extracardiac conduit for repair of their congenital heart defect, we recommend initial repair of the pectus excavatum followed at 6 weeks or later by repair of the cardiac lesion to eliminate possible extrinsic compression of the conduit by the depressed sternum. We avoid simultaneous cardiac and pectus excavatum repair because of potential associated major complications.

Adolescent↗
PubMed1987

Surgical correction of pectus carinatum.

Pectus carinatum is an infrequent but eminently correctable chest wall deformity. It is encountered much less frequently than pectus excavatum. In 12 years, from 1973 to 1985, 152 pectus carinatum (16.7%) and 758 pectus excavatum deformities (83.3%) were corrected. It occurs more frequently in boys (119 patients) than girls (33 patients). The majority, 89 cases, were symmetric, while 49 were asymmetric, and 14 were mixed deformities (ipsilateral carinatum, contralateral excavatum). In almost half the patients the deformity was not identified until after the 11th birthday. A family history of chest wall deformities was present in 26%, and of scoliosis in 12%. Associated musculoskeletal abnormalities were identified in 34 patients (scoliosis 23, Poland's syndrome 4, neurofibromatosis 2, Morquio's disease 2, vertebral anomalies 1, hyperlordosis 1, and kyphosis 1). Surgical correction required bilateral resection of the third through seventh costal cartilages in 143 patients, and unilateral resection in nine patients with an isolated abnormality. A single osteotomy was used in 88 patients and a double osteotomy in 53 patients. In 11 cases no osteotomy was required. Mixed deformity with posterior angulation of the sternum was managed by osteotomy and anterior displacement. The remaining cases had sternal osteotomy and fracture of the posterior cortex to correct anterior angulation. The operation was completed with a low complication rate 3.9% (pneumothorax 4, wound infection 1, atelectasis 1, and local tissue necrosis 1). Three patients required revision with additional unilateral lower cartilage resection for persistent malformation of the costal arch. All patients ultimately had a satisfactory result.

Adolescent↗
PubMed1986

Pulmonary agenesis (aplasia), esophageal atresia, and tracheoesophageal fistula: a different treatment strategy.

This is a report of a patient with esophageal atresia, distal tracheoesophageal fistula, and right pulmonary agenesis who survived for 10 months. Death was due to progressive respiratory failure following a complicated clinical course. Several lessons were learned. First, the remaining lung is at high risk. Since the number of respiratory units in these infants is already decreased, the loss of more units has a more profound effect than in an otherwise healthy child. Second, while the establishment of esophageal continuity is important, all attempts to perform an esophagoesophagostomy should be abandoned if doing so further jeopardizes the solitary lung. Third, since all of these children have some degree of tracheomalacia, early tracheostomy should be considered. The tracheostomy will not only act as a tracheal stent but will also avoid progressive laryngeal pathology, which would result from long-term endotracheal intubation.

Abnormalities, Multiple↗
PubMed1986

Juxtapancreatic intestinal duplications with pancreatic ductal communication: a cause of pancreatitis and recurrent abdominal pain in childhood.

Pancreatic duplications with ductal communications should be included in the differential diagnosis of any child presenting with recurrent abdominal pain of unknown etiology and should be considered as a possible cause of pancreatitis in childhood. Such duplications most likely arise from nonregressing diverticula of the pancreatic bud during embryologic development. Their clinical presentation is unique from other duplications because of their anatomic association with the pancreatic duct. Pain and weight loss are the major presenting complaints, although many patients have nausea and vomiting. Serum chemistries, in particular the serum amylase, are usually normal and are of little help in the differential diagnosis. Radiographic evaluation has not been particularly helpful in the past. ERCP, ultrasonic examination, and CT scan show great promise, however. Operative intervention should be tailored for the individual patient. The operation performed will depend upon operative findings. Intraoperative pancreatograms or cystograms are very helpful in differentiating these cysts from others at the time of operation. Pathologically, most of the duplications have a thickened muscular coat that usually has some evidence of inflammation. They are usually lined with gastric mucosa. Except in the most severe cases, the pancreas is histologically normal, suggesting that most of the pain experienced by these patients is secondary to inflammation within the duplication. The inflammatory response may completely destroy the mucosal lining and cause fibrosis within the muscular coat of the duplication. In those instances, these lesions cannot be differentiated from pancreatic pseudocyst. This may account for some of the "idiopathic" pseudocysts reported in the literature.

Abdomen↗
PubMed1985

Retroperitoneal germ cell tumors in childhood. A clinical and pathologic study of 11 cases.

During the last 54 years at the Children's Hospital 11 children (10 female, 1 male) had been treated for an extragonadal germ cell tumor arising in the retroperitoneum. There were eight teratomas (five mature, three immature), two endodermal sinus tumors and one tumor with a mixture of both components. Abdominal pain or discomfort was the usual presenting complaint, with the average age at diagnosis being 18 months. On physical examination, each child had a palpable abdominal mass usually localized in the upper quadrants. The finding of calcification, bone or teeth, on radiologic study was most helpful in establishing a preoperative diagnosis of teratoma. The preferred treatment for children with mature and immature teratomas is complete surgical resection; decisions regarding adjuvant therapy for patients with immature tumors must be evaluated on an individual basis. The prognosis remains guarded for children with unresectable primaries or those with endodermal sinus tumor. Of three tumor-related deaths, two were due to metastatic endodermal sinus tumor and one resulted from extensive local growth by immature teratoma. Successful management of children with endodermal sinus tumor requires surgery aimed at debulking or complete resection in combination with aggressive adjuvant chemotherapy.

Child, Preschool↗
PubMed1985

Pectus excavatum in children: pulmonary scintigraphy before and after corrective surgery.

Regional distribution of pulmonary function was evaluated preoperatively and postoperatively with xenon-133 perfusion and ventilation scintigraphy in 17 patients with pectus excavatum. Ventilatory preoperative studies were abnormal in 12 of 17 patients, resolving in seven of 12 postoperatively. Perfusion scans were abnormal in ten of 17 patients preoperatively; six of ten showed improvement postoperatively. Ventilation-perfusion ratios were abnormal in ten of 17 patients, normalizing postoperatively in six of ten. Symmetry of ventilation-perfusion ratio images improved in six out of nine in the latter group. The distribution of regional lung function in pectus excavatum can be evaluated preoperatively to support indications for surgery. Postoperative improvement can be documented by physiological changes produced by the surgical correction.

Adolescent↗
PubMed1985

Mediastinal germ cell tumors in childhood. A clinical and pathological study of 21 cases.

Twenty-one patients aged 16 years or less had been treated for a primary mediastinal germ cell tumor at the Children's Hospital, Boston Massachusetts, during the last 54 years. There were 13 boys and eight girls with the average age at diagnosis being 7 years (range 2 weeks to 16 years). Twelve mediastinal germ cell tumors were classified as pure teratoma, five contained embryonal carcinoma admixed with other germ cell components, and four were pure embryonal carcinoma. Of 12 patients with pure teratoma, 10 underwent complete surgical resection and were alive and well 1 to 13 years later; two children left untreated died of complications related to local tumor growth. Complete surgical resection was possible for only two of nine patients with embryonal carcinoma; both received adjuvant therapy and were alive and well 3 and 20 years later. Seven patients received radiation and/or chemotherapy but died of residual or metastatic disease. Successful treatment for children with embryonal carcinoma requires an operation aimed at either debulking or complete resection (if possible) coupled with early and aggressive combination chemotherapy. The role of radiation in primary therapy remains undefined with regard to curative intent.

Adolescent↗