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Biomedical subjects

M L Levin

Publications and source records attributed to M L Levin.

At least 37 records · Page 2Linked to original sources
PubMed1994

Unilateral renal papillectomy via laser or incisional techniques: chronic functional effects in the dog.

OBJECTIVE: To determine if selective renal papillectomy would impair urinary concentrating ability, thereby decreasing urinary calcium concentration. METHODS: Left papillectomy was performed in dogs using either incisional (n = 6) or Neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (n = 5) techniques. Split renal function studies were then performed four months postoperatively to determine the effect on multiple parameters including inulin and para-aminohippurate (PAH) clearance, free water reabsorption, and calcium concentrations. Partially infarcted kidneys (n = 6) were evaluated in a similar fashion to determine the role of impaired glomerular filtration rate (GFR) in the observed concentrating defect occurring after papillectomy. RESULTS: Papillectomized kidneys demonstrated impaired free water reabsorption, resulting in a decreased urinary osmolality and an increased fractional excretion of water. Osmolar clearance [Na+] and Na+ excretion were unaffected by papillectomy, whereas [Ca++] was significantly reduced. While a slight defect in free water reabsorption existed following partial infarction, urinary osmolality was only minimally decreased, fractional excretion of water was unchanged, and Na+ excretion was decreased. CONCLUSIONS: The concentrating defect induced by papillectomy via either sharp excision or laser ablation is due to loss of medullary tissue and is greater than the defect resulting from impaired GFR, which is presumably due to decreased medullary solute delivery and increased flow of water in remaining nephrons. Since the physiologic consequences of papillectomy (formation of less concentrated urine with decreased [Ca++]) have potential clinical applicability, further study of this concept is warranted.

Animals↗
PubMed1994

Aminoglycoside nephrotoxicity: keys to prevention.

The kidneys are the primary site of aminoglycoside clearance; any factor that permits renal parenchymal accumulation increases the risk of aminoglycoside nephrotoxicity. The most common underlying cause is excessive aminoglycoside administration (especially in women or elderly patients). To minimize the risk of nephrotoxicity, select loading and maintenance aminoglycoside dosages based on estimated creatinine clearance. Also, monitor peak and trough serum aminoglycoside levels, replenish volume, and correct potassium and magnesium abnormalities. If possible, avoid giving aminoglycosides to patients with hepatic dysfunction or to those receiving other nephrotoxic drugs or radiocontrast agents.

Aminoglycosides↗
PubMed1993

Improvement of lipid abnormalities associated with proteinuria using fosinopril, an angiotensin-converting enzyme inhibitor.

OBJECTIVE: To examine whether reducing protein excretion in patients with proteinuric renal disease using an angiotensin-converting enzyme inhibitor, fosinopril sodium, would be accompanied by an amelioration of the associated hyperlipidemia. DESIGN: A randomized, placebo-controlled, double-blind study of 12 weeks, followed by 23 weeks of an open-label trial using fosinopril. SETTING: Outpatient renal clinics. PATIENTS: Twenty-six patients (age range, 28 to 70 years) with mild to moderate renal impairment and proteinuria associated with type II diabetes (15 patients) and other causes of nondiabetic renal disease (11 patients) completed the double-blind phase of the study. All patients except one were men. INTERVENTION: Fosinopril, 10 mg initial oral daily dose (randomized trial), and 20 mg orally once a day (open-label phase). MEASUREMENTS: Proteinuria and serum lipids (total cholesterol, high-density lipoprotein, and low-density lipoprotein [LDL] cholesterol, and lipoprotein(a) protein). RESULTS: In a group of 17 patients treated with fosinopril, protein excretion decreased from 5.56 to 4.28 g/d, a reduction of 1.28 (95% CI, -2.49 to -0.08). The reduction was associated with a decrease in serum total cholesterol from 6.39 to 5.82 mmol/L, a decrease of 0.58 mmol/L (CI, -1.01 to -0.15 mmol/L). In a group of nine patients treated with placebo, neither protein excretion (from 5.11 to 4.81 g/d, a change of -0.29 g/d [CI, -1.78 to +1.13 g/d]) nor serum total cholesterol (from 6.08 to 5.77 mmol/L, a change of -0.31 mmol/L [CI, -0.78 to +0.13 mmol/L]) change significantly. At the end of the double-blind phase, plasma lipoprotein(a) protein decreased in the fosinopril-treated group (from 3.94 to 3.33 mg/dL, a reduction of 0.60 mg/dL [CI, -1.02 to -0.18 mg/dL]) but not in the placebo group (from 2.85 to 3.19 mg/dL, a change of +0.34 mg/dL [CI, -0.53 to +1.2 mg/dL]). Dietary protein and fat intake were similar in the two groups throughout the study. In 16 patients who completed an extended open-label phase, fosinopril was associted with a decrease in protein excretion from 4.53 to 3.22 g/d, a reduction of 1.29 g/d (CI, -2.54 to -0.05 g/d), which was associated with a reduction in serum total cholesterol (from 6.37 to 5.54 mmol/L, a decrease of 0.84 mmol/L [CI, -1.59 to -0.08 mmol/L]), LDL cholesterol (from 4.38 to 3.72 mmol/L [a decrease of 0.68 mmol/L [CI, -1.33 to -0.03 mmol/L]), and plasma lipoprotein(a) protein (from 3.58 to 2.81 mg/dL, a reduction of 0.82 mg/dL [CI, -1.58 to -0.05 mg/dL]). CONCLUSION: The angiotensin-converting enzyme inhibitor, fosinopril, can result in a sustained reduction in serum total cholesterol, LDL cholesterol, and plasma lipoprotein(a) protein levels in conjunction with a partial reduction in proteinuria.

Adult↗
PubMed1993

An additional case of pachygyria, joint contractures and facial abnormalities.

Two previous case reports have described an apparently new lethal syndrome consisting of pachygyria, joint contractures and facial abnormalities (Winter et al., 1989; Tsukahara et al., 1990). Another report describes a non-lethal case in which dysmorphic features were not noted (Massa et al., 1988). We now report on what appears to be an additional lethal case. This male infant had a lethal condition with features of large fontanelle, pachygyria with incomplete opercularization, varus contractures of the hands and feet, small palpebral fissures, hypertelorism, a small penis, cryptorchidism, camptodactyly and a sandal gap deformity. These cases appear to represent a new lethal lissencephaly syndrome associated with arthrogryposis and facial dysmorphism, which we propose to call the Winter-Tsukahara syndrome.

Abnormalities, Multiple↗
PubMed1992

Reversibility of long-standing urinary tract obstruction requiring long-term dialysis.

Urinary tract obstruction of longer than 4 to 6 weeks' duration is usually said to be irreversible. Older reports of unilateral obstruction have documented return of kidney function after longer periods of obstruction. The duration of bilateral obstruction compatible with return of life-sustaining renal function is poorly defined. We report herein three cases of long-standing urinary tract obstruction leading to apparent dialysis-dependent end-stage renal disease, where relief of obstruction eventually led to discontinuation of dialysis.

Aged↗
PubMed1991

Transient expression of trisomy 21 and monosomy 7 following cyclosporin A in a patient with aplastic anemia.

We present a patient with severe idiopathic aplastic anemia with no previous chromosomal abnormalities who developed trisomy 21 and monosomy 7 during treatment with intravenous (i.v.) cyclosporine. The abnormal karyotype disappeared when the drug was changed to the oral form. This cytogenetic aberration, previously unreported in association with cyclosporine, may reflect either a direct drug effect or the emergence of a hidden myelodysplastic cell clone subject to preferential survival during immunosuppression.

Administration, Oral↗
PubMed1990

Eosinophilia-myalgia syndrome due to L-tryptophan ingestion. Report of four cases and review of the Maryland experience.

Eosinophilia-myalgia syndrome (EMS) is a recently described clinical entity that has been ascribed to taking over-the-counter preparations of the amino acid L-tryptophan. We describe 4 patients with EMS, 3 of whom presented with eosinophilic fasciitis, and we review the epidemiology of EMS reported in Maryland and discuss the possible pathophysiology of the disease. EMS should be considered in the differential diagnosis of severe myalgia, eosinophilia, and eosinophilic fasciitis.

Administration, Oral↗
PubMed1990

Prospective analysis of laser photophacofragmentation.

Several recent reports have discussed the potential benefits of using the Nd:YAG laser to photofragment the nucleus prior to cataract extraction. We attempted to determine the efficacy and safety of photophacofragmentation prior to cataract surgery. We selected 32 patients for the laser photofragmentation category and 37 patients for the control group. We compared these patients with both phacoemulsification and extracapsular cataract extraction. There was no apparent difference between the four subgroups in endothelial cell loss postoperatively. There was a significant decrease in the amount of ultrasonic time required to remove the cataract for patients who had prior treatment with the YAG laser. However, although this was statistically significant, it did not alter the patient's total surgical time nor the outcome of surgery. We feel that photophacofragmentation introduces needless increased risk to the patient and recommend guarded use of this approach.

Cell Count↗
PubMed1990

Bipedicle myocutaneous flap repair of cicatricial ectropion.

We present a new approach to the bipedicle myocutaneous upper eyelid to lower eyelid flap in the repair of cicatricial ectropion in lower eyelid reconstruction, and in the release of tension caused by a previous cheek rotational flap. By incorporating the pedicles into the flap design, we prevent the persistent lymphedema and the raw tissue placed against exposed epidermis encountered in previous bipedicle myocutaneous flaps. Although there may be disadvantages associated with this procedure, we have not encountered any to date. Advantages of this procedure include the double source of blood supply and the superior cosmetic result as well as the avoidance of a second operative procedure. We recommend the use of the bipedicle myocutaneous flap in selected cases.

Cicatrix↗
PubMed1990

Complex roots of Lotka's integral equation for a special model of net maternity rates.

"An attempt to obtain the solutions of Lotka's integral equation has been made in this paper by assuming a Pearsonian Type III function for the age distribution of the net maternity rates. The shifting of the origin of the function from the traditional value of age zero to the most meaningful lower boundary of the reproductive interval gave rise to an analytical expression of the equation with interesting properties most of which have not yet been encountered in similar endeavors."

Age Factors↗