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Biomedical subjects

J L Murphy

Publications and source records attributed to J L Murphy.

At least 37 records · Page 2Linked to original sources

Adaptation to a diet low in protein: effect of complex carbohydrate upon urea kinetics in normal man.

1. Urea kinetics were measured by using prime/intermittent oral doses of [15N15N]urea in five healthy men taking formula diets adequate in energy and containing either 70 or 35 g of protein/day. In some studies the low-protein diet was supplemented with non-starch polysaccharides in the form of ispaghula husk or ripe bananas. 2. On the 70 g of protein/day diet urea production was 132% of intake. Only 54% of the urea produced was excreted in the urine with 46% being salvaged in the colon; 90% of the salvaged nitrogen was retained in the metabolic nitrogen pool. 3. On the 35 g of protein/day diet the small decrease in urea production rate compared with that on the 70 g of protein/day diet was not significant, but only 36% of the urea produced was excreted in urine, with the majority, 64%, being salvaged. 4. The extent of urea-nitrogen salvaging on the 35 g of protein/day diet was similar in magnitude to the decrease in nitrogen intake, with the effect that the sum of intake and salvaged nitrogen did not differ between the 35 and the 70 g of protein/day diets. This implies that quantitative control is exerted over the rate at which urea nitrogen is salvaged. 5. The addition of non-starch polysaccharides to the 35 g of protein/day diet had a demonstrable effect upon faecal weight and composition, but did not exert any significant influence upon urea kinetics.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗

Renal tubular acidosis in children treated with trimethoprim-sulfamethoxazole during therapy for acute lymphoid leukemia.

The antibiotics trimethoprim (TMP) and sulfamethoxazole (SMZ), when used in combination, can cause metabolic acidosis, renal bicarbonate wasting, and growth failure. Retrospective review of repeated random serum chemistries from 10 children receiving TMP-SMZ and maintenance chemotherapy for acute lymphoid leukemia revealed low serum bicarbonate (P = .0002) and elevated serum chloride (P less than .0005) concentrations. These values normalized after all medications were discontinued. Prospective study of 8 children receiving TMP-SMZ and chemotherapy for acute lymphoid leukemia revealed lower serum bicarbonate concentrations and higher urine pH following a dose of TMP-SMZ than paired values obtained more than 3 days after a dose. Four children (50%) met serum bicarbonate and urinary pH criteria for the diagnosis of renal tubular acidosis soon after a dose of TMP-SMZ. The occurrence of TMP-SMZ-induced renal tubular acidosis has implications for the acid-base balance of children receiving TMP-SMZ on a long-term basis.

Acidosis, Renal Tubular↗

Energy content of stools in normal healthy controls and patients with cystic fibrosis.

Stool energy losses and the sources of energy within the stool were determined in 20 healthy controls and 20 patients with cystic fibrosis while on their habitual pancreatic enzyme replacement treatment. Stool energy losses were equivalent to 3.5% of gross energy intake in healthy children (range 1.3-5.8%). Despite a comparable gross energy intake, stool energy losses were three times greater in patients with cystic fibrosis than controls averaging 10.6% of gross energy intake (range 4.9-19.7%). Stool lipid could account for only 29% and 41% of the energy within the stool in controls and patients with cystic fibrosis respectively and was poorly related to stool energy. Approximately 30% of the energy within the stool could be attributable to colonic bacteria in both the healthy children and patients with cystic fibrosis. These results suggest that stool energy losses in healthy children are relatively modest but that even when patients with cystic fibrosis are symptomatically well controlled on pancreatic enzyme replacement, raised stool energy losses may continue to contribute towards an energy deficit sufficient to limit growth in cystic fibrosis. As the energy content per gram wet weight remains relatively constant (8 kJ/g), stool energy losses may be estimated from simple measurements of stool wet weight.

Adolescent↗

Lymphatic fistula after vascular reconstruction: a case-control study.

A retrospective case-control study was carried out to assess the importance of lymphatic fistulas that develop after vascular reconstruction and to determine the risk factors associated with them. The authors compared 35 patients who had lymphatic fistula after vascular reconstruction with 70 control patients, taken from the same database. They found a significant difference between the two groups only in age and indication for surgery: lymphatic fistulas were more likely to develop in older patients and in patients who underwent aortobifemoral bypass for limb salvage rather than for claudication (p less than 0.05).

Aged↗

Decreased urinary citrate in premature infants with lung disease.

Urinary citrate prevents nephrocalcinosis in adults. Premature infants have a high incidence of nephrocalcinosis. We measured urinary citrate (Ucit) and creatinine (Ucre) concentrations in infants with and without lung disease. Ucit was lower in the infants requiring mechanical ventilation than in the controls (mean = 9.7 vs. 15, p = 0.05). Ucit/Ucre ratios were lower in hypercarbic (mean = 0.95 vs. 1.47 in normocarbic, p less than 0.05) and acidotic (mean = 0.57 vs. 1.44 in nonacidotic, p less than 0.004) premature infants. The lowered Ucit of premature infants with lung disease (and acidosis or hypercarbia) may predispose to nephrocalcinosis by increased urinary lithogenesis.

Citrates↗

Factors affecting survival after rupture of abdominal aortic aneurysm: effect of size on management and outcome.

Between 1970 and 1985, 172 consecutive patients (146 men, 26 women) underwent repair of ruptured abdominal aortic aneurysms. The mean age was 69.8 years. The overall death rate was 49.4%. The most significant predictors of death were an intraoperative urine output under 100 ml, systolic blood pressure less than 90 mm Hg on admission or in the operating room, cardiac arrest and a history of collapse. Discriminant analysis correctly classified 90% of the survivors and 84% of the nonsurvivors. Aneurysm size was documented in 133 cases; the average diameter was 8.78 cm, and 13 (10%) of the aneurysms were smaller than 6.0 cm. A correct diagnosis was made preoperatively in 46% of these 13 cases compared with 77% overall (p less than 0.05), and the time from arrival to transfer to the operating room was 6.71 versus 2.37 hours (p less than 0.05). The death rate for patients who had the small aneurysms was 77% versus 45% for those with larger aneurysms (p less than 0.06). This study confirms the continuing poor results after repair of ruptured abdominal aortic aneurysms. A subset of patients having small aneurysms (less than 6.0 cm) require an aggressive approach to diagnosis and treatment.

Aged↗

Trimethoprim/sulfamethoxazole-induced renal tubular acidosis.

A child was evaluated for growth failure at the University of California, San Diego. On two occasions the patient had renal bicarbonate wasting, acidosis, and growth failure associated with trimethoprim/sulfamethoxazole (TMP/SMZ) administration. On both occasions, the acidosis resolved and the growth rate normalized following a period without receiving TMP/SMZ. Renal tubular acidosis and growth failure may occur as a result of TMP/SMZ therapy in children.

Acidosis, Renal Tubular↗

Angiotensin-converting enzyme inhibitor-induced cough.

A 65-year-old woman started taking enalapril 2.5 mg daily for hypertension. Twelve days later she complained of a persistent, dry cough. Due to the coughing and a preexisting cystocele, she developed stress incontinence and a marked decline in her functional status. The coughing and incontinence resolved with the discontinuation of enalapril. During a subsequent hospitalization the patient received captopril 6.25 mg twice daily for congestive heart failure. Within 24 hours the dry cough recurred. It resolved with the discontinuation of the drug. Cough is a symptom that is generally not recognized as a drug side effect. However, increasing numbers of case reports document angiotensin-converting enzyme inhibitor-induced cough. Although the actual frequency and mechanism are currently unknown, the dry cough typically begins early in the course of therapy. It may be specific to this pharmacologic class rather than to one individual agent. Age and sex may be contributing factors. While cough has been considered a minor side effect, unnecessary hospitalizations and inappropriate treatments may easily result. Even minor adverse reactions may have an impact on a patient's quality of life.

Aged↗

Severe bilateral renal disease: correlation of antenatal and autopsy findings.

We report 20 infants with severe bilateral renal disease examined by prenatal ultrasound and by autopsy. In 17, the prenatal and pathologic diagnoses correlated well. Although the prenatal and autopsy findings differed in the three remaining cases, the autopsy confirmed the presence of severe bilateral renal abnormalities. All 20 pregnancies were complicated by oligohydramnios, which was severe in 60 per cent. Most of these fetuses had malformation of other organ systems. This series supports the utility of prenatal ultrasound examinations, but emphasizes the need for postnatal evaluation of congenital renal disease including pathologic examination of tissue when possible for correct classification and genetic counselling.

Female↗

Follow-up of infants with obstructive uropathy detected in utero and treated surgically postnatally.

Thirty-four infants with obstructive uropathy detected by prenatal ultrasonography at 34 +/- 0.56 weeks (SE) had surgery during the first 2 years of life. The growth and renal function of the 25 children after being followed for over 1 year are described. Twelve children had unilateral disease, and 13 had bilateral disease. All 12 children with unilateral disease grew at or above the fifth percentile and had normal renal function (glomerular filtration rate, 101 +/- 7 mL/min/1.73 m2). Thirteen children with bilateral disease were followed for 26.1 +/- 3.4 months. Growth was good: 10 of the 13 grew at or above the fifth percentile. The serum creatinine was 0.7 +/- 0.2 mg/dL, and the glomerular filtration rate was 91 +/- 10 mL/min/1.73 m2. One child required chronic dialysis. The prenatal diagnosis of urinary tract anomalies followed by early intervention may improve the long-term outcome of children with obstructive uropathy.

Child, Preschool↗

Comparison of Marlex and Gore-tex to repair abdominal wall defects in the rat.

Marlex and Gore-tex, two prosthetic materials used to close abdominal wounds, were compared with respect to strength and adhesion formation. A 2.5 X 3.5-cm full-thickness area of abdominal wall was excised in 32 CD rats. The defect was repaired using identically sized patches of Marlex or 1-mm Gore-tex, determined by alternate assignment, and sutured with continuous 4-0 Gore-tex. Adhesion formation was graded at necropsy and recorded photographically in each animal. The mean adhesion index (none = 0, maximal = 4) was 1.37 +/- 0.12 and 2.62 +/- 0.12 (mean +/- SEM) for Gore-tex and Marlex groups respectively (p less than 0.005, unpaired t-test). A template was used to fashion 2-cm coronal strips of abdominal wall for tensile-strength testing. The relative strengths were 2.67 +/- 0.14 and 3.02 +/- 0.16 kg/cm (mean +/- SEM) for the Gore-tex and Marlex groups respectively (NS). Histologically, there were more epithelioid giant cells and less collagen formation in the Gore-tex group. Abdominal wall reconstruction with Gore-tex resulted in wound strength equal to that of Marlex and fewer adhesions. Gore-tex is preferred when prosthetic material and viscera are in close proximity.

Abdominal Injuries↗

Follow-up of infants with bilateral renal disease detected in utero. Growth and renal function.

We studied 69 infants who had urinary tract abnormalities detected by antenatal ultrasound examination. There were 21 intrauterine or immediate neonatal deaths; in all 21 infants, severe bilateral renal disease incompatible with life was found at autopsy. Six of the live-born infants with abnormal results of antenatal ultrasound examinations had a normal urinary tract after birth. Of the remaining 42 infants, the prenatal diagnosis was confirmed with renal ultrasound and other studies during the first week of life. Twenty-one of 42 infants had bilateral renal disease. We obtained follow-up data on 19 of 21 of these infants. Twelve of 19 had obstructive uropathy that was treated surgically. After one to 51 (mean, 18) months of follow-up, renal function varied. Ten of 19 patients had a calculated glomerular filtration rate greater than or equal to 79 mL/min/1.73 m2. One infant required long-term ambulatory peritoneal dialysis. Renal function (glomerular filtration rate, 74 +/- 5 mL/min/1.73 m2) and growth (height percentile, 41 +/- 8) were unexpectedly good considering the severity of the urinary tract abnormalities. Prenatal detection of bilateral renal disease followed by careful medical and surgical management results in a favorable outcome with good growth and renal function.

Adolescent↗