A case of malignant lymphoma, undifferentiated, Burkitt's type with high antibodies to Epstein-Barr virus

A 5-year-4-month-old girl was admitted to Taipei Municipal Jen-Ai Hospital because of a rapidly enlarging right submandibular tumor. The diagnosis of malignant lymphoma, undifferentiated, Burkitt's type was made by distinctive histopathological features. Positive serological findings related to Epstein-Barr virus infection were disclosed. Complete remission has been achieved since the treatment with high-dose cyclophosphamide was given, and no signs of relapse have been found yet.

A mouse model of pneumonitis induced by Chlamydia trachomatis: morphologic, microbiologic, and immunologic studies

Swiss-Webster white mice were infected with Chlamydia trachomatis organisms through intranasal inoculation. It was found that a typical interstitial pneumonitis could be induced. Histopathologic findings showed that the lung infiltration was predominantly polymorphonuclear cells and was most prominant on Day 2. The cellular infiltrate gradually changed to mononuclear cells after Day 3. Intracytoplasmic inclusions were frequently found in the interstitial cells and occasionally in the bronchial epithelial cells. Typical chlamydial bodies (elementary, intermediate, and reticulate forms) were identified by electron microscopy. The organisms were recovered from mouse lungs on Days 1--7, with the highest yields on Day 2. This correlated with the peak of lung infiltration seen by histologic examination. Antibodies specific to the infecting immunotype began to appear between Day 7 and Day 10 after inoculation and lasted until Day 35 without a decline in titers. A delayed hypersensitivity reaction was observed by footpad test from Day 5 to Day 21, with the peak reaction at Day 7. This study showed that the mouse model could be used to study the immunopathogenesis of C trachomatis infection.

The effect of a body burden of methylmercury on hepatic regeneration

The model of hepatic regeneration is chosen to study the effect of methylmercury burden on cell proliferation. The results show that chronic methylmercury burden impedes the rate of thymidine incorporation during the process of DNA synthesis. At 24 hours after partial hepatectomy, thymidine incorporation in the mercury exposed rats is 53% of the controls. Counts of labeled hepatocytes in radioautographic preparations also support this observation. This remarkable difference in DNA synthetic activity at 24 hours also reflects in the DNA content and liver, weights at 72 hours after partial hepatectomy (Liver weights 2.36 +/- 0.21 gm/100 gm B. W. vs. 2.67 +/- 0.31 gm/100 B. W., P < 0,05; DNA contents 160.78 +/- 36.76 microgram/gm vs. 214.80 +/- 37.908 microgram/gm, P < 0.05). After two weeks, no significant difference is noted in liver weight, DNA content and synthetic activity. On the other hand, protein content and biosynthesis in the liver of methylmercury burdened rats shows no significant difference from the controls in all the periods studied. From these data it is concluded that the dividing fraction of hepatocytes is reduced in methylmercury-treated group at an early stage of regeneration when cell proliferation is most active.

Regression of Hodgkin disease in the mediastinum: a mathematical model

Twenty-seven patients with mediastinal Hodgkin disease were teated either by radiation therapy or chemotherapy. The rates of tumor regression were measured and were fitted into a three-parameter Gompertzian model. Tumor regression was more pronounced and prompt in patients treated with radiotherapy. The Gompertzian model matched the radiation therapy data closely in the first 90 days after initiation of therapy in cases of approximately equal tumor size.

Mechanisms of prolongation of pre-ejection period in patients with left ventricular disease

In order to determine the mechanism underlying prolongation of the pre-ejection period in patients with left ventricular disease, 11 patients with congestive cardiomyopathy and 29 with coronary artery disease, 10 of whom were taking beta-adrenergic blocking drugs, were studied non-invasively. Recordings of carotid pulse, and apex, phono-, and echocardiogram were obtained. In the absence of treatment with beta-blocking drugs, prolongation of pre-ejection period correlated closely with incoordinate left ventricular wall movement during isovolumic contraction assessed from simultaneous apex and echocardiograms. There was no correlation between pre-ejection period index (PEPI) and end-diastolic dimension and PEPI correlated poorly with fractional shortening and peak Vcf. A PEPI of greater than 140 ms was associated with incoordinate contraction in all but one case, and of less than 140 ms with normal contraction in all. Therapeutic doses of beta-blocking drugs caused prolongation of PEPI to a greater extent than would have been predicted from wall movement during isovolumic contraction. Incoordinate left ventricular contraction and a negative inotropic effect both therefore prolong PEPI, but by different mechanisms, whose effects can be separated in individual patients using non-invasive methods based on echocardiography.

The effect of methylmercury on isolated cardiac tissues

The effect of methylmercury hydroxide (MMH) on the frequency of spontaneously beating atrial-SA node and on the isometric tension of electrically stimulated left atrial (1 Hz) preparation isolated from rats were investigated. The tissues were also fixed for ultrastructural study at the end of the experiments. We found that MMH, at low doses (0.5 and 2ppm), increased the frequency of contractions and the isometric tension of isolated atria and decreased the isometric tension of isolated papillar muscles, and at higher doses (greater than 2ppm), decreased all the above parameter. Morphologically, there were dilation and swelling of mitochondrial and sarcoplasmic reticulum. Occasionally, deposits of amorphous material in the mitochondria and myofibrillary degeneration of myocardial fibers were noted. It is concluded the MMH has direct effect on intracellular organelles (mitochondria, sarcoplasmic reticulum, and myofibril) of myocardial tissue and induces functional changes of atria and papillary muscles

Induction of colitis in hamsters by topical application of antibiotics

Syrian hamsters are exquisitely sensitive to clindamycin; as little as 1 mg/kg of clindamycin given systemically causes a fatal colitis. Clindamycin and erythromycin were applied topically daily to the shaved backs of Syrian hamsters in a hydroalcoholic vehicle. A daily dose of 0.1 mg of clindamycin was lethal to more than half the hamsters and 1 mg to all the animals. The antibiotic-associated toxin from Clostridium difficile was present in their cecal material. Based on body surface areas and estimated usual volumes applied, the lethal dose in hamsters is not dissimilar to that given humans for acne. Oral tetracycline therapy protected the animals from clindamycin toxicity, but the animals died three days after stopping tetracycline if topical clindamycin applications were continued.

Dissociation between ion permeability and the lethal action of polyene antibiotics on Candida albicans

Kinetic data on potassium release from and killing of Candida albicans by the four polyene antibiotics amphotericin B, amphotericin B methyl ester hydrochloride, nystatin, and nystatin methyl ester hydrochloride are presented. The nystatins were relatively more effective than the amphotericins in causing potassium release rather than killing. These data suggest that the aqueous channels or pores formed by the polyene antibiotics are not central to the lethal action of the drugs.

Kinetics of association of amphotericin B with vesicles

Amphotericin B associates with vesicles prepared from phosphatidylcholines. The influence of lipid composition on the initial rate of amphotericin B association with vesicles was examined using stopped-flow kinetic measurements. A relationship was found between the tightness of packing of phosphatidylcholine molecules in the vesicles and the initial rate of amphotericin B association. Shortening of the fatty acyl chain length of saturated phosphatidylcholines and increasing the number of double bonds in the fatty acyl chains of unsaturated phosphatidylcholines enhance the initial rate, whereas addition of cholesterol of the bilayers reduces the rate. The initial rate of association with phosphatidylcholine-sterol vesicles follows the order, thiocholesterol greater than androst-5-en-3beta-ol greater than epicholesterol greater than ergosterol greater than cholesterol and is thus inversely related to the order of phospholipid-sterol affinity, as revealed by permeability, surface area, and magnetic resonance measurements. These data suggest that the initial rate of amphotericin B uptake into vesicles depends on competition between lipid-lipid and amphotericin-lipid interactions.

Mechanical properties of the dog renal capsule

The renal capsule is an important determinant of whole kidney volume/pressure relationships. To gain further insights into its possible role we examined the mechanical properties of the dog renal capsule using standard materials testing procedures. From each of four locations on the kidney surface, the following mechanical properties of the renal capsule were determined: elastic modulus (force/unit of cross-sectional area theoretically required to double the length of the specimen), tensile stiffness (force/unit width theoretically required to double the length of the specimen), ultimate strength (stress at time of fracture of the specimen), and maximum strain (percent strain at time of the fracture of the specimen). We found that the elastic modulus of the renal capsule from all capsular sites was substantially greater than values previously reported for dog aorta. The stiffness of the capsule covering the anterior-posterior surface of the kidney was found to be about 50% greater than the stiffness of the capsule covering the lateral and polar surfaces of the kidney. The ultimate strength of the anterior-posterior capsule was significantly greater than that of the lateral or polar capsule. This finding may explain the clinical observation that the spontaneous rupture of the renal capsule and parenchyma associated with the acute swelling of transplant rejection is confined almost exclusively to the lateral and polar portions of the renal capsule and cortex. The mean maximum strain at each capsular site was about 35%. This degree of circumferential expansion corresponds to about a doubling of kidney volume. Thus, this observation suggests that the renal capsule is at risk to undergo spontaneous rupture when renal volume increases of this magnitude are observed.

Interaction of delta-chymotrypsin with proflavine

A 1:1 molar stoichiometry has been found for the noncovalent bonding of proflavine with δ-chymotrypsin. The dissociation constant at pH 7.6 is 0.025 mM which is similar to that found by Glazer for the reaction of proflavine with α-chymotrypsin. The difference spectrum produced by the proflavine–δ-chymotrypsin interaction has been studied as a function of pH. It would appear that a group with pK of approximately 6.5 is involved.