PubMed Health⌕ Search

Biomedical subjects

L W Martin

Publications and source records attributed to L W Martin.

At least 19 recordsLinked to original sources
PubMed1991

Impedance measurement of absolute blood flow using an angioplasty catheter: a validation study.

An angioplasty catheter was developed to allow measurement of absolute coronary blood flow during interventional procedures. This method uses electrical impedance changes induced by a 0.5 ml bolus of 5% dextrose solution and indicator-dilution principles. The indicator is injected through a port located just proximal to the dilating balloon and the resulting changes in blood impedance are measured by electrodes at the catheter tip. Excellent linear correlations were found between known flow in 2 to 4 mm to diameter plastic tubes and catheter measurements (r = 0.99) and between timed collection canine femoral artery flow and catheter measurements (r = 0.97). Final validation was performed in canine coronary arteries using electromagnetic flowmeter data as the standard (r = 0.94). Thus accurate clinical determination of absolute coronary blood flow can be accomplished using this relatively inexpensive and simple catheter technique.

Angioplasty, Balloon, Coronary↗
PubMed1991

Dexamethasone facilitates release of the neuropeptide alpha-MSH.

alpha-Melanocyte stimulating hormone (alpha-MSH) has important host defense properties, in part similar to those of corticosteroids. Previous research suggests that secretion of alpha-MSH and of ACTH are controlled separately. The relationship between release of alpha-MSH and the activity of the hypothalamic-pituitary-adrenal axis in the rabbit was examined by monitoring changes in circulating alpha-MSH, ACTH, and corticosterone in response to endotoxin and corticotropin-releasing hormone (CRH), both with and without dexamethasone pretreatment. Endotoxin (1 microgram/kg IV) did not cause alpha-MSH release, but it did increase plasma concentrations of ACTH and corticosterone. Similarly, CRH (1 and 10 micrograms/kg IV) did not affect plasma alpha-MSH, whereas it stimulated ACTH and corticosterone release. Dexamethasone pretreatment abolished the responses of ACTH and corticosterone to either stimulus and did not modify circulating alpha-MSH after CRH. In contrast, dexamethasone pretreatment did result in a significant increase in plasma alpha-MSH after a dose of endotoxin that was ineffective alone. These data indicate that corticosteroids can facilitate the release of alpha-MSH, a powerful anti-inflammatory hormone. Since corticosteroids are released with certain challenges, this facilitatory activity may be important to the host response.

Adrenocorticotropic Hormone↗
PubMed1991

Pediatric bicycle trauma.

Bicycle-related trauma is a serious pediatric problem. Serious injuries and even fatalities can occur, and care must be taken to avoid undertreating these patients. In an effort to further define the problem, 201 consecutive patients admitted for bicycle trauma were reviewed. The patients ranged in age from 3 to 16 years and 76% (153/201) were male. Head trauma was the most common admission diagnosis (99/201; 49%). Fourteen per cent (28/201) were admitted to the Intensive Care Unit and 23% (47/201) required an operative procedure. The average hospital stay was 3 days; however, patients who were admitted at least 24 hours after injury had an average hospital stay of 7 days.

Adolescent↗
PubMed1990

Cardiac contusion in pediatric patients with blunt thoracic trauma.

To investigate the prevalence of myocardial contusion associated with blunt chest trauma in the pediatric age group, all patients admitted to our institution during a 6-month period with blunt thoracic trauma severe enough to produce a pulmonary contusion or rib fracture were prospectively evaluated. Cardiac evaluation was undertaken, including a multiple-gated acquisition (MUGA) cardiac scan, serial electrocardiograms (ECG), and serum creatine phosphokinase (CPK) and CPK isoenzymes. Seven patients, ranging in age from 2 1/2 to 18 years, with rib fractures or pulmonary contusion by chest roentgenograph were identified. One patient was injured as a passenger in a motor vehicle accident, five were struck by automobiles as pedestrians, and one sustained traumatic asphyxia when a car, supported by a jack, fell on his chest. All had at least one other major organ system injured. All patients had pulmonary contusions as determined by chest radiograph, and two had associated rib fractures. In 43% (three of seven) of patients, a significant cardiac contusion was identified, defined by abnormal right or left ventricular wall motion and a decreased ejection fraction on MUGA scan, and confirmed by an increase in cardiac enzymes and isoenzymes. However, in contrast with adults, no patients had ECG abnormalities. This limited series suggests that cardiac contusion may occur frequently in pediatric patients who have suffered from blunt thoracic trauma significant enough to result in pulmonary contusion. An MUGA scan provides a rapid, noninvasive assessment of cardiac damage in this setting. Further studies will be required to determine the clinical significance and long-term consequences of traumatic myocardial damage in the pediatric population.

Accidents, Traffic↗
PubMed1990

Multiple endocrine neoplasia type II B with symptoms suggesting Hirschsprung's disease: a case report.

A 3-year-old child was referred with a tentative diagnosis of Hirschsprung's disease because of life-long constipation and "megacolon" demonstrated radiographically. Our rectal biopsy revealed hyperganglionosis suggestive of multiple endocrine neoplasia (MEN) type II B. This, in addition to an elevated serum calcitonin level, prompted surgical removal of her thyroid, which appeared grossly normal but on sectioning, contained a medullary carcinoma in each lobe. She remains disease-free 5 years later. Gastrointestinal symptoms are a significant component of the MEN type II B syndrome, and often antedate the full phenotypic expression of the syndrome and the development of potentially lethal endocrine neoplasms. On the basis of this experience, it is recommended that MEN II B be included in the differential diagnosis of chronic constipation.

Child, Preschool↗
PubMed1990

The influence of donor age on graft survival in renal transplantation.

The current supply of kidneys from cadaver and living related donor sources is not sufficient to meet the demand. As a result, alternative sources of renal allografts are being explored, including very young donors and anencephalic newborns. However, data on the success of transplanting kidneys from very young donors are limited and conflicting. The purpose of this study was to determine whether the function and survival of renal grafts obtained from newborns and very young donors is different from that for grafts obtained from older donors. Thirty-six cadaveric donors under the age of 3 years, including seven anencephalic newborns, were evaluated. Allograft recipients ranged in age from 12 months to 57 years. The clinical outcome for these donor organs was compared with the graft survival for 136 kidneys transplanted from cadaver donors over age 3 years at our institution. There was a 65% 6-month and 64% 1-year graft survival in recipients of kidneys from donors greater than or equal to 3 years. Survival of grafts from donors under 12 months of age (n = 16) was significantly decreased compared with donors age 3 years and older, with a 31% 6-month (P less than .01) and 19% 12-month survival (P less than .001). Grafts obtained from anencephalic donors did not differ in survival or function from kidneys obtained from other donors less than 12 months of age. Survival for renal allografts from donors age 13 months to 3 years was also decreased relative to older donors: 55% at 6 months (P greater than .1) and 40% at 1 year (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Acute phase response to endotoxin: rise in plasma alpha-MSH and effects of alpha-MSH injection.

Endotoxins, cell wall components of bacteria, cause a number of biological effects, presumably via induction of potent cytokines. Previous research suggests that the neuropeptide alpha-melanocyte-stimulating hormone (alpha-MSH) and its COOH-terminal tripeptide reduce the effects of cytokines. These molecules evoke antipyretic and anti-inflammatory effects in vivo. Localization of alpha-MSH within lymphocytes and recent observations that alpha-MSH receptors are widespread and that circulating alpha-MSH increases after systemic injection of endogenous pyrogen, a cytokine-containing extract, suggest that the peptide modulates host defense reactions. One aim of the present experiments was to learn whether a rise in circulating alpha-MSH occurs in synchrony with aspects of the acute phase response (APR) in conscious rabbits given endotoxin. A second aim was to learn whether administration of a single large dose of alpha-MSH inhibits all aspects of the APR induced by a low dose of endotoxin. The results indicate that the concentration of circulating alpha-MSH in rabbits does increase along with other changes in the APR (e.g., increase in corticosterone), which suggests that the peptide is widely available to modulate cytokine effects after endotoxin. Contrary to expectations based on previous results, a large dose of the peptide given intravenously inhibited only fever and not other aspects of the APR. The results suggest that the rise in circulating alpha-MSH is an aspect of the APR and that an acute increase in the circulating peptide caused by intravenous injection does not inhibit all other aspects of the host response to endotoxin.

Acute-Phase Reaction↗
PubMed1979

Renal homotransplantation in children.

Ninety-six renal transplants in 77 pediatric patients are reported with follow-up as long as 12 1/2 years. Thirteen of the first 14 patients are living with a functioning kidney after eight to 12 1/2 years. The patient survival for the entire group is 78%. Sixty-four percent are living with a functioning transplanted kidney. Splenectomy was initially performed at the time of transplant but has been discontinued because of concern that splenectomy in the immunosuppressed patient was related to an increased occurrence of septic complications. Anencephalic newborn infants have been found to be a satisfactory source of cadaver donor kidneys. Growth and development have been satisfactory when the transplant is performed prior to 12 years of age, if it functions well, and if an alternate-day regimen of steroid administration is followed. Both boys and girls have now passed through puberty with their transplanted kidneys, have married, become parents, and are leading essentially normal lives. A plea is made for earlier transplantation in small children with irreversible progressive renal failure before they develop severe stunting of growth and before the need for prolonged dialysis.

Adolescent↗
PubMed1979

Hirschsprung's disease with skip area (segmental aganglionosis).

Hirschsprung's disease is characterized by a single aganglionic segment of colon extending distally to the anal margin. Well documented reports of segmental aganglionosis have been rare. We report a case of segmental aganglionosis in which there were two distinct aganglionic segments resected. The entire transverse colon between the two aganglionic segments was normally ganglionated, preserved, and utilized and functions in a normal fashion.

Colon↗
PubMed1979

Retroperitoneal lymph node dissection for Wilms' tumor.

Nephrectomy for Wilms' tumor was performed on 58 patients over a 20-yr period, and retroperitoneal lymphadenectomy was performed on 35 who presented with no demonstrable metastases. The survival rate was 100% for 19 clinical group I patients with negative nodes. Positive nodes in 9 instances led to 5 long-term survivors and significantly influenced staging as a guide for further therapy.

Humans↗
PubMed1979

Portal hypertension secondary to choledochal cyst.

Two patients with portal hypertension secondary to choledochal cyst are reported and combined with four others previously reported in the literature. Choledochal cysts may, by extrensic compression, cause partial or complete portal vein obstruction, portal hypertension and esophageal varices. Needle biopsy of the liver is probably not a reliable means of differentiating choledochal cyst from other intrahepatic causes of portal hypertension. Internal drainage of the choledochal cyst has been performed in four patients and in each instance resulted in satisfactory portal decompression.

Adolescent↗
PubMed1978

Leukemic infiltration of the testis during long-term remission.

Of 33 boys with acute lymphocytic leukemia treated at the Cincinnati Children's Hospital during 1971--1974, 14 remained in clinical and bone marrow remission for periods longer than 2.5 yr. Of these 14 patients, 8 then developed testicular leukemia. In 7 of these 8 patients, testicular infiltration was the first or only evidence of relapse. In 2 of the patients the gonads were not grossly abnormal, and testicular relapse was discovered as a result of routine wedge biopsy before therapy was to have been stopped. This experience has led to our policy of routine testicular biopsy in boys with acute lymphocytic leukemia who have had continuous remission for 3 yr and who are otherwise candidates for discontinuance of maintenance therapy.

Adolescent↗
PubMed1978

Emergency splenectomy for idiopathic thrombocytopenic purpura in children.

Splenectomies were performed in 30 children out of a total of 183 with idiopathic thrombocytopenic purpura (ITP). Of these 30, ten splenectomies were performed on an emergency basis. Significant spontaneous gross hematuria, gastrointestinal bleeding or epistaxis appear to represent harbingers of intracranial hemorrhage and constitute indications for emergency splenectomy.

Adolescent↗
PubMed1978

Transplantation of cadaver kidneys from anencephalic donors.

Of 14 potential anencephalic donors, the kidneys of six were transplanted to recipients ranging in age from 4 to 19 years and in weight from 8 to 49 kg. In three recipients, serum creatinine levels are less than 1.0 mg/dl 1.5 to 9.5 years after transplant. The transplants failed in two for technical reasons; in one, the kidneys were lost by rejection. The other anencephalic infants were not suitable as donors because of rapid deterioration of vital signs (4), ABO incompatibility (3), and inability to perfuse the kidney (1). Successfully transplanted kidneys from this source rapidly increase in size and function to accomodate even large recipients.

Adolescent↗
PubMed1977

Malrotation with gastric volvulus, midgut volvulus, and pancreatitis.

A 2-year-old child with intestinal malrotation had simultaneous gastric volvulus, midgut volvulus, acute pancreatitis, and gastric perforation, followed postoperatively by a temporary period of both lactosuria and sucrosuria. The gastric volvulus and midgut volvulus resulted in both proximal and distal obstruction of the duodenum, reproducing clinically a previously reported experimental model designed to produce pancreatitis. Operative reduction of the midgut volvulus and the gastric volvulus and repair of the gastric perforation was accomplished. The child has had normal growth and development during the ensuing nine years.

Child, Preschool↗
PubMed1977

Retinal phlebitis in the Irvine-Gass syndrome.

We reviewed the pathology records from January 1965 through July 1975 for aphakic eyes. After exclusion of unsuitable cases, ten eyes (nine patients) with cystoid macular edema and 142 eyes without cystoid macular edema were studied. Clinical ophthalmic records were available for five of the ten eyes with the Irvine-Gass syndrome. Histologic sections were examined, revealing a significant correlation between the Irvine-Gass syndrome and retinal phlebitis, which has not been reported previously, as well as cyclitis and vitritis. Anterior segment operative complications tended to be more prevalent in eyes with the Irvine-Gass syndrome than in those without the Irvine-Gass syndrome, although the assocation was not statistically significant (P less than .1). Retinal trypsin digestion showed the phlebitis to be distributed posteriorly within primary and secondary retinal veins, frequently occurring near points of bifurcation. The changes in permeability seen in the Irvine-Gass syndrome may be due to this retinal phlebitis and to a generalized inflammation-induced increase in capillary permeability. The case of the phlebitis is not known.

Adult↗
PubMed1977

Intussusception in the 1970s: indications for operation.

Eighty-one patients with proven intussusception were treated at the Cincinnati Children's Hospital from 1970-1974. One died. Seven of these had ileo-ileal intussusception, all treated surgically. Seventy-four had colonic components of their intussusceptions. In 58 of these patients (78%), reduction was attempted at barium enema, successfully in 32. Hydrostatic reduction was abandoned and the patient operated upon when the intussusception was not pushed out of the colon, when barium failed to reflux into several loops of ileum, or when there was a large persistent filling defect in the cecum or terminal ileum. Primary operation without barium enema was done in 16 patients. The appearance of intestinal obstruction by abdominal x-ray seemed to give the best warning about the complicated, incarcerated, or gangrenous intussusception. Primary operation is, therefore, advised for the patient with intussusception if there is x-ray evidence of intestinal obstruction. The age of the patient and the duration of his symptoms do not seem important in this regard, except as they correlate with peritonitis or obstruction. For the patient without peritonitis or intestinal obstruction, attempted reduction of the intussusception at barium enema seems safe and effective, regardless of the patient's age or duration of his symptoms.

Barium Sulfate↗