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Biomedical subjects

J Herrera

Publications and source records attributed to J Herrera.

At least 109 records · Page 6Linked to original sources
PubMed1988

The renal functional reserve in health and renal disease in school age children.

The capacity to increase the glomerular filtration rate (GFR) in response to stimuli is a characteristic of the healthy kidney. To establish normal limits of this functional reserve is of clinical relevance because its loss may be the earliest indication of renal damage. For this purpose we have used a method applicable in clinical practice: one-hour clearances of creatinine (CCr) done under water diuresis, before (unstimulated) and two hours after (stimulated) a test meat meal, taking a single postmeal blood sample. Urine collection was done by voluntary voiding under direct supervision. In studies done in 14 control subjects, inulin clearance (CIn)/CCr ratios were (mean +/- SEM) 1.04 +/- 0.05 and 0.96 +/- 0.03, in unstimulated and stimulated clearances, respectively. In studies repeated at three to nine week intervals, we found a variation coefficient (mean +/- SEM) of 24.5 +/- 3.11% and 9.25 +/- 1.43% (P less than 0.001) for the unstimulated and stimulated CCr, respectively. The corresponding values for CIn were 19.3 +/- 2.36% and 9.17 +/- 1.19% (P less than 0.001), suggesting that stimulated GFR values are more stable. Unstimulated and stimulated GFR and renal functional reserve (stimulated CCr - unstimulated CCr) were studied in 260 school aged children, ages 6 to 16 years (140 boys and 120 girls). The distribution of the renal functional reserve was approximately Gaussian but the distribution of the urinary creatinine excretion, unstimulated and stimulated GFR had considerable positive skewness.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1988

Relationship between glomerular filtration rate and renal blood flow at different levels of protein-induced hyperfiltration in man.

1. We studied the relationship between changes in glomerular filtration rate (GFR) determined as inulin clearance (CIn), and changes in renal blood flow (RBF), determined as p-aminohippurate clearance (CPAH), after the ingestion of a large (1.35 +/- SEM 0.04 g/kg, n = 9), moderate (1.08 +/- 0.03 g/kg, n = 10) or mild (0.55 +/- 0.02 g/kg, n = 8) protein load given as a meat meal. Control subjects (n = 10) received a carbohydrate meal. 2. CIn and CPAH increased after a protein meal. Two hours after eating the test meal, GFR levels were (mean +/- SEM) 160.0 +/- 13.8 (P less than 0.05), 141 +/- 7.69 and 127.8 +/- 9.07 ml/min in the groups that received a large, moderate and mild protein load, respectively. Peak CIn values after the meal were 211.6 +/- SEM 14.92 (P less than 0.001), 177.5 +/- 10.88 (P less than 0.01) and 129.0 +/- 8.72 ml/min after a large, moderate and mild protein load, respectively. 3. At peak GFR levels after the meal, filtration fraction (FF) (CIn X 100/CPAH) increased significantly (P less than 0.02) with the large and with the moderate protein load, but not with the mild protein load. 4. There was a significant (P less than 0.001) positive relationship between increments of FF and increments of CIn, but not CPAH, whether the values were expressed as post-meal/pre-meal ratios or as absolute changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Atrial natriuretic factor increases after a protein meal in man.

1. The renal function changes induced by dietary protein are thought to result from the activity of hormonal factors that remain as yet undefined. Since a meat meal and high dose atrial natriuretic factor (ANF) infusions have similar effects on glomerular filtration rate, natriuresis and kaliuresis, we decided to investigate the possibility that a protein meal could stimulate ANF activity. 2. We studied 10 normal volunteers who had a fixed protein and sodium intake for 7 days before the experiments. The subjects received a meat meal (1-1.5 g of protein/kg) and, on a separate occasion, a carbohydrate meal that had a similar caloric, sodium and potassium content. Diuresis was stimulated with water ingestion, and urine collections were obtained before the meals (baseline) and after the meals for a period of 3 h. Blood samples were obtained 30 min and 5 min before the meals and every hour for 3 h in the period after the meal. 3. The protein meal, but not the carbohydrate meal, was associated with parallel increments in plasma immunoreactive ANF (i-ANF), natriuresis, kaliuresis and glomerular filtration rate (estimated from creatinine clearances) which reached peak values 2-3 h after the meal. The mean increment of plasma i-ANF after the protein meal represented a twofold increase over baseline levels. 4. We conclude that ANF may participate in the physiological response to an oral protein load.

Atrial Natriuretic Factor↗
PubMed1988

Increased urinary excretion of prostaglandin E in patients with idiopathic hypercalciuria.

1. Because urinary prostaglandin excretion could play a role in idiopathic hypercalciuria (IH), we studied the excretion of prostaglandin E (PGE), calcium and sodium at various urine flows in 21 patients (14 males) with urolithiasis and IH, seven stone formers (five males) with normal calciuria and 20 controls (11 males). Dietary composition was comparable and sodium intake was restricted to 100-120 mmol/day. 2. Analyses were performed on 30 min urine collections obtained after overnight water deprivation and during water diuresis. Male IH patients had increased levels of urinary PGE at all ranges of urine flow. PGE excretion correlated directly with urine flow in patients and controls, but the slope of this relationship in individual IH male patients was steeper than in controls (P less than 0.01). Calciuria correlated directly with urine output in patients with IH but not in controls. Calcium and sodium excretion were directly correlated (P less than 0.0001) in patients and controls. There were no significant differences between absorptive IH (seven patients) and renal IH (eight patients). There were no significant differences between stone formers with normocalciuria and control subjects. 3. The findings suggest that increased urinary PGE could play a role in the hypercalciuria syndrome, possibly by promoting natriuresis.

Adolescent↗
PubMed1988

A carbamazepine trial in chronic, treatment-refractory schizophrenia.

Carbamazepine was given to 12 chronic, treatment-refractory schizophrenic patients for 5 weeks. No overall change was found, but four patients significantly improved while eight worsened. Given the paucity of successful treatments for refractory schizophrenia, further study of carbamazepine appears warranted.

Adult↗
PubMed1988

Exacerbation of psychosis after discontinuation of carbamazepine treatment.

Carbamazepine alone or carbamazepine plus neuroleptic was administered to 20 chronic schizophrenic patients. Upon abrupt discontinuation two of the 20 patients had exacerbations of their psychoses characterized by paranoia, hostility, and agitation. The authors discuss the possibility of a carbamazepine withdrawal syndrome.

Adult↗
PubMed1988

Urinary prostaglandin E and kallikrein activity in glomerular hyperfiltration induced by a meat meal in man.

Because renal vasodilator systems may be involved in the physiologic response to a protein meal, we studied the relationship of prostaglandin E (PGE) and kallikrein (KE) activity to the renal hemodynamic changes induced by a meat meal. Ten normal subjects on a maintenance diet providing 1 g protein per kg and 100 mmol Na daily were studied before and after a meal of 86 g of meat protein, once without medication, and again after treatment with indomethacin (150 mg daily for 3 days before and 50 mg the morning of the test). A carbohydrate meal of similar caloric, Na and K content was used in control studies. Glomerular filtration rate (GFR, inulin clearance), renal blood flow (RBF, para-aminohippurate [PAH] clearance), PGE and kallikrein urinary excretion were determined. All studies were performed during water diuresis to avoid bladder catheterization. The protein load induced an increase in GFR (ml/min, mean +/- s.e.m.: baseline 107.2 +/- 6.05, peak postmeal 146.4 +/- 6.79, p less than 0.01) and RBF (baseline 529.7 +/- 42.9, postmeal 678.9 +/- 61.9, p less than 0.05). Renal hemodynamic changes were unrelated to changes in urinary PGE and KE excretion. Indomethacin treatment inhibited PGE excretion by 73% during the test meal but did not modify the protein-induced hyperfiltration. Our results suggest that these renal vasodilator systems are not primarily responsible for the hyperfiltration response. In addition, the data show that inhibition of prostaglandin synthesis is not a practical approach to prevent glomerular hyperfiltration in clinical practice.

Adult↗
PubMed1988

Special operative events in the first case of liver grafting after heart transplantation.

Combined heart-liver transplantation is the only therapeutic possibility for patients with familial hypercholesterolemia IIa. A 12-year-old boy with this metabolopathy underwent a double transplant in two steps (different donors). This original alternative was chosen to assure a safer procedure in this critical situation. Details of intraoperative events are described. Cholesterol and LDL decreased to physiologic levels after liver transplantation. The child's condition is optimal 1.5 years after surgery.

Child↗
PubMed1988

Atypical hepatic tuberculosis presenting as obstructive jaundice.

A 78-yr-old female with a short history of malaise, anorexia, mild pyrexia, and obstructive jaundice is presented. A diagnosis of tuberculosis of the liver and gallbladder was established at laparotomy. In spite of anti-tuberculous therapy, the patient died on the 5th postoperative day. Widespread miliary tuberculosis affecting the lung, kidneys, spleen, and mesenteric lymph nodes was observed in postmortem studies, with strikingly severe involvement of the intrahepatic bile ducts. Saccular dilatation of the bile ducts alternating with areas of stenosis and narrowed intrahepatic bile ducts was seen. A correlation of the radiological and hepatic postmortem findings is discussed. The atypical presentation of tuberculosis in present times and the causes of jaundice in atypical cases of hepatic tuberculosis are discussed. The rarity of gallbladder tuberculosis is pointed out.

Aged↗
PubMed1987

Evaluation of antihypertensive efficacy of lisinopril compared to metoprolol in moderate to severe hypertension.

A double-blind controlled, randomized, parallel, multicenter 12-week study was conducted to compare the antihypertensive efficacy of lisinopril with that of metoprolol in treatment of moderate to severe hypertension. Initially, 118 patients were recruited on lisinopril and 61 on metoprolol; and for the purpose of efficacy analysis at week 8, 115 patients on lisinopril and 60 on metoprolol were included. The doses of lisinopril or metoprolol were 40-80 mg/day and 100-200 mg/day, respectively. At week 4, the pretreatment diastolic blood pressure of 111 mm Hg was decreased to 97 mm Hg (p less than 0.01) with lisinopril: metoprolol decreased the diastolic blood pressure from 110 to 99 mm Hg (p less than 0.01). Similar decreases were noted at week 8; however, the drop in blood pressure with lisinopril was not significantly different from that with metoprolol. Systolic blood pressure also demonstrated a decrease of about 18 mm Hg with lisinopril and 12 mm Hg with metoprolol (p less than 0.01). This larger decrease in systolic blood pressure with lisinopril was statistically significant at week 4 (p less than 0.05). These decreases in systolic blood pressures were maintained at week 8, again with statistical significance (p less than 0.01). Of the 118 lisinopril-treated patients, four were discontinued from lisinopril therapy because of headache, dizziness, rash, flushing, or lymphadenopathy. Four patients out of 61 (9.8%) were discontinued from metoprolol therapy because of fatigue, somnolence, asthenia, weight gain, flatulence, tremor, or bronchospasm. In conclusion, lisinopril 40-80 mg once daily is as effective as metoprolol 100-200 mg once daily in reducing diastolic blood pressure in patients with moderate to severe hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1987

Correlation study between prolactin and androgens in male patients with systemic lupus erythematosus.

The hypothalamic-pituitary-gonadal axis was studied in 8 male patients with systemic lupus erythematosus (SLE), both before and after intravenous administration of luteinizing hormone-releasing hormone (LH-RH). We provide evidence herein that resting serum levels of estrone are increased and that resting serum testosterone (T) and dihydrotestosterone (DHT) levels are decreased in male patients with SLE. The decreased serum T levels were observed even after the IV administration of 25 micrograms of LH-RH. The high basal serum prolactin (PRL) levels observed in these patients with SLE is a novel finding not previously reported that could explain why serum T and DHT levels are low in this syndrome. We observed a decrease in the pituitary response to LH-RH stimulation; this low response could also be a hormonal manifestation of hyperprolactinemia. Furthermore, it has been suggested that PRL plays a role in immunocompetence, and therefore it could have influence either directly or indirectly in the altered immunoregulation observed in SLE.

Adult↗