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Biomedical subjects

L S Fang

Publications and source records attributed to L S Fang.

36 records · Page 2Linked to original sources
PubMed1985

Fractional excretion of sodium. Exceptions to its diagnostic value.

Determining the cause of acutely deteriorating renal function is a common problem in clinical nephrology. The fractional excretion of filtered sodium (FENa) has been demonstrated to be a reliably discriminating test between prerenal azotemia and acute tubular necrosis. However, with increasing clinical use of the FENa, numerous reports of low FENa (less than 1%) have appeared. The clinical settings of these reports include oliguric and nonoliguric acute tubular necrosis, urinary tract obstruction, acute glomerulonephritis, hepatorenal syndrome, renal allograft rejection, sepsis, and drug-related alterations in renal hemodynamics. One particular urinary index cannot be expected to reliably discriminate between prerenal azotemia and acute renal failure in all cases. The utility of the FENa test in the differential diagnosis of acute renal failure must be interpreted in conjunction with the patient's clinical course and the use of additional urinary and serum tests.

Acute Kidney Injury↗
PubMed1984

Low fractional excretion of sodium. Occurrence with hemoglobinuric- and myoglobinuric-induced acute renal failure.

Ten patients with myoglobinuric and hemoglobinuric acute renal failure demonstrated low fractional excretion of sodium (FENa) values (less than 1%) during the oliguric phase of their course. Acute renal failure secondary to hemoglobinuria developed in five patients, and five demonstrated acute deterioration with myoglobinuria. The mean serum creatinine level increased from 1.1 mg/dL (range, 0.6 to 1.7 mg/dL) to a maximum of 6.9 mg/dL (range, 2 to 13.1 mg/dL). Although three patients required dialysis, all individuals eventually returned or were returning toward their baseline renal function at discharge. The importance of a low FENa in the setting of myoglobinuric and hemoglobinuric renal failure is reviewed. The findings in this report raise the possibility that a common mechanism may underlie the renal injury in both types of pigment toxicity.

Acute Kidney Injury↗
PubMed1984

Nifedipine-induced renal dysfunction. Alterations in renal hemodynamics.

Nifedipine caused acute, reversible deterioration in renal function in four patients with chronic renal insufficiency. The absence of hypotension, clinical course, benign urinary sediments, and normal results of renal ultrasound examinations excluded acute tubular necrosis, pyelonephritis, interstitial nephritis, obstructive uropathy, and acute glomerulonephritis. It is postulated that this slow calcium channel blocker produced deleterious intrarenal hemodynamic alterations in the setting of moderate to severe renal functional impairment. Nifedipine may alter renal function by blocking calcium entry into renal vascular smooth muscle, thereby reducing the efficacy of vasoconstrictor hormones in regulation of renal blood flow and glomerular filtration rate. An alternative explanation is that nifedipine may inhibit the compensatory synthesis of vasodilatory prostaglandin E2 analogous to the clinical observation of acute deterioration in renal function by nonsteroidal anti-inflammatory drugs in patients with pre-existing renal insufficiency. These observations suggest that clinicians should monitor renal function closely and exercise caution when administering nifedipine to patients with underlying renal insufficiency.

Aged↗
PubMed1984

Parathyroid surgery in patients with renal failure.

A subtotal parathyroidectomy was performed in 32 patients with hyperparathyroidism and renal dysfunction. Minimal long-term sequelae were observed [two patients with recurrent hyperparathyroidism (6.2%), one patient with persistent hypoparathyroidism (3.1%)]. This experience is compared with reports in the literature advocating total parathyroidectomy and autotransplantation. A subtotal parathyroidectomy remains the preferred approach at this institution. Patients with elevated alkaline phosphatase levels before surgery should be monitored carefully for early postoperative hypocalcemia. The low incidence (3.2%) of hyperparathyroidism observed in patients following successful renal transplantation indicates that hypercalcemic allograft recipients should be observed for at least 4 months before contemplating surgical intervention.

Adolescent↗
PubMed1982

Effects of various agents on flagellar activity, flagellar autotomy and cell viability in four species of Chlamydomonas (chlorophyta: volvocales).

Over 200 strains of green algal flagellates, representing about 100 species, were examined for their suitability as experimental organisms for studies of flagellar activity. The cells of all species shed their flagella under unfavourable conditions of temperature or pH, or in the presence of alcohols, detergents or toxic agents of various kinds. For further studies of flagellar activity, motility and autotomy (biologically induced shedding) in particular, we selected four species of Chlamydomonas: C. dysosmos Moewus, C. moewusii Gerloff, C. monoica Strehlow and C. reinhardtii Dangeard. Agents found to inhibit motility without inducing death or flagellar autotomy included azide, arsenite, thiosulphate, cyanide, ferricyanide, hydroxylamine, chloral hydrate, malonate, p-chloro-mercury benzoate and cytochalasin-B, each in a limited range of concentrations which differed according to species and strain. Higher concentrations of these agents caused the flagella to be shed. Since flagellar autotomy is a means by which a cell can quickly reduce the area of its permeable surface, it may have a positive survival value for species liable to be subjected to unfavourable physicochemical conditions.

Azides↗
PubMed1980

Single-dose amoxicillin therapy for urinary tract infection. Multicenter trial using antibody-coated bacteria localization technique.

Urine specimens from 134 women with acute, uncomplicated urinary tract infection at three medical centers were examined by the antibody-coated bacteria (ACB) assay. Patients with negative assays (suggesting bladder infection alone) were randomized to receive either a single 3-g oral dose of amoxicillin trihydrate or conventional ten-day courses of sulfa-methoxazole-trimethoprim or oral ampicillin sodium. Comparable results were obtained with the three regimens for ACG-negative infection: 90% eradication of the original organism with single-dose amoxicillin, 100% with sulfamethoxazole-trimethoprim, and 96% with ampicillin. The overall incidence of ACB positivity was 32.1%, ranging from 8% to 63% at the three institutions. This difference seemed to be related to the ease of access to medical care: women with easy access having low rates of ACB positivity and those with poor access having high rates.

Acute Disease↗
PubMed1980

Low fractional excretion of sodium with contrast media-induced acute renal failure.

Risk factors, clinical courses, and urinary indices were examined in 12 consecutive patients with contrast media-induced acute renal failure. A high prevalence of preexisting renal disease, diabetes, vascular disease, and compromised cardiac output was observed. All patients had transient oliguria one to four days in duration, and all patients had return of renal function to their baseline values within five to ten days. Consistently low urinary sodium concentration and fractional excretion of sodium (FENa) were seen during the oliguric phase of the acute renal failure. Fractional excretion of sodium of less than 1% persisted for up to five days despite unequivocal renal function deterioration. The findings raise the possibility that acute renal failure secondary to contrast media may be mediated either by decreases in renal perfusion or by acute tubular obstruction.

Acute Kidney Injury↗
PubMed1978

Efficacy of single-dose and conventional amoxicillin therapy in urinary-tract infection localized by the antibody-coated bacteria technic.

Urine specimens from 61 women with symptoms of cystitis who are infected with amoxicillin-sensitive organisms were examined by the antibody-coated bacteria assay. Patients with negative assays were randomized to receive either a single 3-g oral dose of amoxicillin or 10 days of amoxicillin, 250 mg, given by mouth four times per day (conventional therapy). Patients with positive assays received conventional therapy. All 43 patients without antibody-coated bacteria in the urine, 22 given single-dose therapy and 21 treated conventionally, were cured of their infection. Of 18 patients with antibody-coated bacteria, nine relapsed within one week of completion of conventional therapy. The results of the antibody-coated bacteria assay appear to predict the therapeutic response: both single-dose and conventional amoxicillin therapy are completely successful in patients with negative assays; in contrast, conventional therapy is ineffective in 50 per cent of patients with positive assays.

Administration, Oral↗
PubMedDate not supplied

Clinical management of urinary tract infection.

The clinical management of urinary tract infection has changed considerably over the last two decades due to the recognition of several important factors: All urinary tract infections are not the same; in particular, deep tissue infection of the kidney and/or prostate requires a very different form of clinical management than does superficial mucosal infection of the bladder. Consistent with these differences, it is now clear that conventional 7-14 day treatment courses are not ideal for most forms of urinary tract infections; deep tissue infection requires more intensive therapy and superficial mucosal infection needs less intensive therapy. In particular, single dose antimicrobial therapy has been a major advance in the management of the most common form of urinary tract infection--acute uncomplicated urinary tract infection of the adult female; such therapy is safe, effective, inexpensive, and the response provides useful clinical information. The recognition of the etiology of the acute urethral syndrome in most patients (true bacteriuria or Chlamydia trachomatis infection) had led to an effective therapeutic approach to this problem. A logical approach to the problem of recurrent urinary tract infection has emerged that is both cost-effective and clinically effective. Finally, a clearer picture of those populations that would benefit most from anatomical study of the urinary tract has been developed. With these advances, this most common of bacterial infections affecting man throughout his lifespan has become much easier to control.

Adult↗
PubMedDate not supplied

Single-dose therapy with trimethoprim-sulfamethoxazole for urinary tract infection in women.

One-hundred-four women with symptoms of lower urinary tract inflammation (dysuria, frequency, and suprapubic tenderness) were randomly assigned to one of two treatment regimens: either a single dose of two double-strength trimethoprim-sulfamethoxazole, (TMP-SMZ) tablets (320 mg of TMP and 1,600 mg of SMZ) or conventional therapy of one double-strength tablet (160 mg of TMP and 800 mg of SMZ) twice a day for 10 days. Eighty-one patients had true bacteriuria; 93% of the infections were eradicated by single-dose therapy and 95% by conventional therapy. Results of an antibody-coated bacteria assay showed no correlation with therapeutic outcome. Clinically important side effects were observed in 4% of patients treated with single-dose therapy and 24% (P less than 0.05) of those treated with conventional therapy. Twenty-three patients had acute urethral syndrome, 14 with and nine without pyuria on initial urinalysis. The 14 with pyuria responded to antimicrobial therapy, whereas those without pyuria did not. This response pattern is consistent with recent data concerning the etiology of acute urethral syndrome. It is concluded that single-dose TMP-SMZ therapy is effective, easily administered, inexpensive, and free from significant side effects, and that it should have broad applicability in the treatment of women with acute, uncomplicated urinary tract infection.

Adolescent↗
PubMedDate not supplied

Treatment of severe lactic acidosis with dichloroacetate.

Four patients with severe lactic acidosis associated with septic shock were treated with sodium dichloroacetate (DCA) (50 mg/kg body wt), an activator of pyruvate dehydrogenase. All patients were in a group with an expected mortality rate of 90-100%, based on previous studies. In one patient, treatment with DCA was associated with a decrease in blood lactate levels from 11.2 mM before treatment to 0.8 mM 16 h later. Markedly elevated blood pyruvate and alanine levels also decreased to normal. After treatment, the arterial blood pH rose to 7.53, and vasopressor agents were no longer needed to support blood pressure. Some degree of biochemical improvement was also noted in the other cases in whom the blood lactate levels before treatment were 15, 17, and 31 mM. However, all three patients eventually died of refractory acidosis.

Acetates↗