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Biomedical subjects

L Berk

Publications and source records attributed to L Berk.

32 records · Page 2Linked to original sources
PubMed1991

Severe chronic active hepatitis (autoimmune type) mimicked by coinfection of hepatitis C and human immunodeficiency viruses.

Severe chronic active hepatitis, defined as the presence of a fivefold increase in serum aminotransferases and a twofold rise in gamma globulin for at least 10 weeks, is considered a progressive immunological liver disease requiring corticosteroid treatment, particularly when serum autoantibodies and a severe lymphoplasmacellular periportal infiltrate are found in the liver biopsy specimen. A 38 year old man who fulfilled the criteria for severe chronic active hepatitis is described. His sex, his homosexuality, and the presence of antibodies against HIV, however, led to the suspicion of a coinfection with hepatitis C virus (HCV) rather than autoimmune disease. The rapid and complete response to alpha interferon treatment and a recently available positive antibody test for HCV supported this view. These findings indicate that a HCV related chronic active hepatitis can present as the severe autoimmune type of chronic active hepatitis. Moreover, as in HBV infection, the response to treatment differs from that of autoimmune severe chronic active hepatitis.

Adult↗
PubMed1991

Alpha lymphoblastoid interferon and acyclovir for chronic hepatitis delta.

Ten patients with chronic hepatitis type D were treated during 4 months with alpha lymphoblastoid interferon in combination with two 2-week courses of acyclovir. Median percentage of HDAg-positive hepatocytes decreased from 11 to 1, p = 0.0225. Patients with no liver HDAg expression after treatment (n = 5) showed improved AST levels (normal in 4) and diminished liver cell inflammation. One patient, who cleared HDAg has complete biochemical remission of his liver disease with 2 years of follow-up. Five patients with persistent, albeit low, HDAg expression in the liver, had continued liver cell destruction (AST elevated and/or abnormal biopsy). No evidence for an enhancing effect of acyclovir for interferon therapy was observed.

Acyclovir↗
PubMed1989

Effect of dietary protein on serum insulin and glucagon levels in hyper- and normocholesterolemic men.

This study was designed to test the effect of dietary protein on blood levels of insulin and glucagon. Twelve normocholesterolemic (less than 200 mg/dl) and 11 hypercholesterolemic greater than 240 mg/dl) healthy male subjects, 31-62 years of age, were randomly given 3 liquid test meals 1 week apart. Meals were identical except for the protein source (soybean, casein, or protein free). Blood was drawn at fasting, and 0.5 and 2 h postprandially. Insulin and glucagon levels were measured by radioimmunoassay. Hypercholesterolemic subjects had a higher (P less than 0.05) insulin/glucagon ratio (1.5) than normocholesterolemic subjects (0.7) 2 h post-prandially when fed the casein test meal. There was no significant difference following the soybean test meal. This implies that the post-prandial insulin/glucagon ratio was affected by the amino acid composition of the diet. There was a consistently higher insulin response to all test meals among hyper- versus normocholesterolemic subjects. These results are consistent with our hypothesis that the hypocholesterolemic effects of soybean protein and the hypercholesterolemic effects of casein were mediated by altered levels of insulin and glucagon.

Adult↗
PubMed1989

Intraocular distribution of intravitreally administered amphotericin B in normal and vitrectomized eyes.

A study was performed to determine how amphotericin B is distributed in the eye after direct intravitreal injection. Radiolabeled amphotericin B was administered by direct injection into the vitreous space of unmodified phakic control or vitrectomized aphakic eyes in the rabbit model. The eyes were removed at different post-injection times, frozen and dissected into anatomical subparts of cornea, aqueous, iris, lens, vitreous and sclera-choroid-retina. The parts were assayed for total radioactivity (expressed as remaining amphotericin B). No accumulation of drug was observed in the cornea, lens, iris or aqueous region. The majority of drug was found in the vitreous cavity. The rate of disappearance of radiolabeled drug or radiolabeled drug degradation products from the vitreous space was similar to the rate of disappearance from the eye. However, progressive accumulation of radioactivity was observed in the sclera-choroid-retina tissue in the unmodified phakic eyes. This was not observed in vitrectomized aphakic eyes. The accumulated radioactivity could have represented drug degradation products or active drug. These results shed light on the distribution of amphotericin B in the eye after direct intravitreal injection, a procedure often employed clinically for fungal endophthalmitis.

Amphotericin B↗
PubMed1988

Long-term follow-up of antiviral combination therapy in chronic hepatitis B.

For patients with chronic hepatitis B e (HBe)-positive hepatitis, long-term results of pilot studies with lymphoblastoid interferon-alpha, acyclovir, or a combination, and of a randomized controlled trial of interferon/desciclovir combination therapy are presented. HBe seroconversion was observed in more than 40 percent of patients treated with combination therapy, 30 percent with interferon therapy, 18 percent with acyclovir, and 0 percent with no treatment. HBe reactivation occurred in two patients with cirrhosis. Hepatitis B surface seroconversion followed HBe seroconversion in 11 to 30 percent of treated patients. HBe seroconversion was significantly related to initial low levels of viral replication and to transient aminotransferase elevation during the second half of the interferon treatment of 16 weeks. Clinical improvement and persistent normalization of aspartate aminotransferase was observed in all patients with HBe seroconversion. Conversion to a state of virus latency (HBe negative) mostly occurred after therapy, suggesting that the specific immunologic host response had been brought about by the suppression of virus replication through antiviral agents. Recommendations for selection of patients for antiviral combination therapy are made on the basis of these long-term results.

Acyclovir↗
PubMed1988

The effect of the thromboxane receptor antagonist BM 13.177 on experimentally induced coronary artery thrombosis in the pig.

We studied the effect of pretreatment with two doses of the thromboxane antagonist BM 13.177 and its solvent on the development of electrically induced coronary artery thrombosis in pigs. Results were compared with those obtained in animals pretreated with intravenously administered acetylsalicylate and its solvent. The effects of both compounds on the overall cardiovascular performance (heart rate, mean arterial blood pressure, cardiac output, systemic vascular resistance) were minimal. In the animals receiving solvent or acetylsalicylate the time to occlusive coronary thrombosis was 33 +/- 4 and 32 +/- 6 min, respectively. BM 13.177, in a dose of 5 mg.kg-1, did not modify the time to thrombotic occlusion (35 +/- 7 min), but in six of the eight animals that had received 10 mg.kg-1 BM 13.177, there was no occlusion within 120 min. In the acetylsalicylate-treated animals, collagen-induced platelet aggregation and plasma thromboxane B2 declined by 72 and 82%, respectively. The decreases were 46 and 20%, respectively, with the higher dose of BM 13.177. It is concluded that, in this porcine model of coronary artery thrombosis, the thromboxane antagonist BM 13.177 effectively suppressed formation of occlusive thrombi whereas acetylsalicylate was ineffective at a dose that lowered arterial thromboxane levels.

Animals↗
PubMed1988

Aging and human cone photopigments.

We used a noninvasive technique to investigate changes in photoreceptor function with aging in observers 13-69 years of age. This technique, steady-state color matching, provides estimates of the optical density of cone photopigments, the illuminance that bleaches half of the photopigment, and the ratio of the primaries required at moderate light levels. In normal human retinas, we found that the optical density for a 4-deg field is affected minimally by aging from the second through the seventh decades. The average optical density is 0.27 +/- 0.054. The optical densities of older observers varied more than those of younger observers. The change in optical density with age is nonmonotonic, with slightly lower values for the youngest and oldest observers in our study. The retinal illuminance that bleaches half of the cone photopigment varied little across observers, averaging 4.37 log Td +/- 0.119. The change with age, which averages 0.00018 log Td per year over all observers, also is nonmonotonic. Moderate illuminance color matches did change with age, as expected, with a monotonic decrease with age in the ratio of the long-wavelength primary to the short-wavelength primary required for the color match.

Adolescent↗
PubMed1984

The effect of the stable prostacyclin analogue ZK 36374 on experimental coronary thrombosis in the pig.

The hemodynamic and antithrombotic action of ZK 36374, a stable carbacyclin derivative of prostacyclin, was studied during electrically-induced coronary artery thrombosis in the open chest anesthetized pig. Infusion of ZK 36374 (100 ng/kg/min, n = 6) had no effect on heart rate and cardiac output, but caused a 20% reduction in mean arterial blood pressure by peripheral vasodilation. In animals receiving solvent or no drug prior to thrombosis induction, the time to occlusive coronary artery thrombosis (TOT) was 30 +/- 2 minutes (mean +/- SEM, n = 17). Pretreatment with an i.v. infusion of ZK 36374 (100 ng/kg/min) prolonged TOT by 50% to 47 +/- 7 minutes (p less than 0.005, n = 6). This prolongation of TOT was not due to the lower blood pressure in the ZK 36374 group, as dihydralazine in a dose that lowered arterial blood pressure to the same extent had no effect on TOT (32 +/- 4 minutes, n = 4). The results indicate that ZK 36374 may be useful in delaying (or preventing) occlusive coronary artery thrombi.

Animals↗
PubMedDate not supplied

Prospective trials for the radiotherapeutic treatment of bone metastases.

Radiation therapy is a proven technique to relieve the pain of bone metastases. Focal painful metastases can be palliated in up to 80 percent of patients. The technique to use for the treatment varies depending on the extent of disease, the prognosis of the patient and physician preference. Most studies indicate that the local treatment of bone metastases with single large treatments is as efficacious as extended courses of treatment. For patients with wide-spread disease, two forms of systemic radiotherapy are available: hemibody irradiation and intravenous injection of radionuclides. Studies have shown the combination of either focal irradiation and hemibody irradiation or focal irradiation and the injection of strontium (89) prolongs the pain-free duration of the patients. All palliative patients with symptomatic bone metastases should be evaluated for radiotherapy.

Bone Neoplasms↗