Characterization of the plasmids of Moraxella bovis

Restriction endonuclease digestions were performed on plasmids purified from Moraxella bovis isolates GRS, Newport, and IBH64. It was determined from single and double digestions of plasmid DNA that GRS and Newport isolates carried 3 large plasmids having molecular sizes of 43.8, 41.3, and 32.8 kilobases (kb). Digestion of the 3 large plasmids and restriction endonucleases Hae III, HindIII, Nde I, and Ava I strongly indicated that these isolates shared structurally identical large plasmids. Timed single digestions with Ava I revealed that the IBH64 isolate carried 2 large plasmids having molecular sizes of 45 and 32.8 kb. The 32.8-kb plasmid was the only large plasmid that appeared to be shared by all 3 M bovis isolates. Two isolates, Newport and IBH64, carried small plasmids in addition to the large plasmids. Restriction maps were constructed for the 43.8-, 41.3-, and 32.8-kb plasmids.

Cell loss in the aging retina. Relationship to lipofuscin accumulation and macular degeneration

We examined the impact of aging on the numbers of photoreceptors and retinal pigment epithelium (RPE) cells, and the number of photoreceptors per RPE cell profile, in selected regions of 30 human eyes. The mean ratio of photoreceptors to RPE cell was higher in the macula than in the paramacula (P less than 0.01) or the equatorial area (P less than 0.001). We found evidence for an age-related loss of RPE in both whites (P less than 0.02) and blacks (P less than 0.0006), although the rate of loss in whites was significantly slower than in blacks. Photoreceptor loss in blacks was inversely correlated with age (P less than 0.04). In whites, however, photoreceptor loss was very significantly and directly correlated with lipofuscin concentration in the opposing RPE (P less than 0.0001) and unrelated to age. The disparity in the rates of photoreceptor and RPE cell loss produced, in older eyes, a higher ratio of photoreceptors per RPE cell profile. In the macula, the ratio for whites over 50 years of age was significantly higher (P less than 0.05) than that in blacks over 50. Our data suggest that the increased phagocytic and metabolic load on the RPE, which ultimately the macula causes a preferential age-related accumulation of lipofuscin in the RPE, which ultimately leads to photoreceptor death. This may prove a useful model of age-related macular degeneration and Stargardt's disease.

The detection of an antibody against IgA allotype A2M 2 and a study of the Am genetic marker among the Han Chinese population

The serum of a woman was found by the Ouchterlony double-diffusion and the hemagglutination inhibition (HAI) methods to have immunoglobulin A (IgA) deficiency. Further investigation using the hemagglutination (HA) test with red cells coated with IgA myeloma proteins of different specificities showed that the serum agglutinated only IgA2-, A2M-1, and A2M 2-coated cells. The patterns of the HAI test with a reference panel confirmed the presence of two specificities. One was anti-IgA2 and the other was a rare antibody against the allotype A2M 2. The anti-A2M 2 was used for population studies. Testing of the Han Chinese population, including family studies, confirms that A2M.1 and A2M.2 have an autosomal dominant mode of inheritance and are controlled by a codominant allele. The distribution of the two Am genetic markers among the Han Chinese population demonstrated A2M.1 with a gene frequency of 0.553 and A2M.2 with a gene frequency of 0.447 (chi 2 = 0.145, 0.80 greater than p greater than 0.70).

In vivo thickness of the human detached retina by ultrasonic signal processing

Fourier operations on digitized radio-frequency (rf) data can provide the most sensitive measure of the thickness of thin, deterministic structures such as membranes. After deconvolution against the system transfer function, the cepstrum and the analytic signal magnitude can provide measures of membrane thickness on the order of a half-wavelength. A total of 19 patients with rhegmatogenous retinal detachments were scanned using a diagnostic ultrasound system adapted for analog to digital conversion of rf data. Data were analyzed using the signal processing techniques described above to measure retinal thickness. Recent retinal detachments tended to be significantly thicker than normal attached retinas, and thickness decreased with the age of detachment. A statistically significant correlation was found to exist between retinal thickness and the duration of detachment.

Formation of alanine and glutamine in chick (Gallus domesticus) skeletal muscle

1. Incubation of extensor digitorum communis muscles from fed chicks in the presence of plasma concentrations of branched-chain amino acids (BCAA) increased the formation of glutamate, glutamine and alanine. This effect was inhibited by 1.5 mM L-cycloserine. 2. 2-Oxoisocaproate (0.1 and 0.5 mM) increased the formation of leucine but decreased that of glutamate, glutamine and alanine. 3. NH4Cl (0.3 mM) increased the formation of glutamine, and decreased the release and intracellular concentrations of glutamate and alanine. 4. Our results demonstrate that alanine and glutamine are synthesized de novo in chick skeletal muscle and demonstrate the similarity in alanine and glutamine synthesis in skeletal muscle between the domestic fowl and mammals.

Pathogenesis of atherosclerosis: I: Role of the nervous system

The new method of lateral carotid artery original-location autograft was used in the present study. An animal model was prepared with which to investigate the neurogenic role in the pathogenesis of atherosclerosis. Two experiments were performed in 16 operated rabbits to whom was fed a cholesterol-rich diet for four months. In the first experiment, the expected results were obtained in 9 rabbits. Significant atherosclerotic plaques were observed in 4 of 9 (44.4%) samples of intact carotid artery; lipid deposition was found in another 3 (33.3%) samples in which atherosclerotic plaques were not observed by the naked eye but were exhibited by light microscopy; negative results were shown only in 2 (22.2%) samples both by the naked eye and by light microscopy. However, atherosclerotic plaques were found only in autograft anastomoses but not within the segment of carotid artery autograft. Then, a second experiment as performed with 7 operated rabbits, and similar results were obtained. These results clearly indicate that the nervous system plays a very important role in the pathogenesis of atherosclerosis.

Ultrastructural and electrophoretic analysis of Treponema hyodysenteriae axial filaments

Axial filaments of Treponema hyodysenteriae were purified and examined by transmission electron microscopy. The size and fine structure of the filaments were similar to those of Treponema zuelzerae and Treponema phagedenis biotype reiterii. Filaments were dissociated by heat and 2-mercaptoethanol and examined by polyacrylamide-gel electrophoresis. Six protein bands were evident, with approximate molecular weights of 39,000, 29,000, 27,000, 22,000, 21,000, and 18,500 daltons. All the proteins reacted with T hyodysenteriae and T innocens rabbit antisera, using the immunoblot technique.

Arachidonic acid, prostaglandin E2 and F2 alpha inhibit leucine degradation in chick skeletal muscle

Arachidonic acid (5 microM), prostaglandin E2 (0.28 microM) and F2 alpha (14 microM) inhibited (P less than 0.01) the rates of net leucine transamination, leucine oxidative decarboxylation and total CO2 production from leucine in extensor digitorum communis muscles from fed ten-day-old chicks. Indomethacin (50 microM) markedly inhibited (P less than 0.01) the rate of PGE2 production in the presence of 5 microM arachidonic acid and prevented the inhibition of leucine degradation by arachidonic acid in skeletal muscle. These results demonstrate that the actions of arachidonic acid on leucine degradation in chick skeletal muscle are mediated by metabolites generated via the cyclooxygenase pathway and that prostaglandins may play a role in the regulation of leucine degradation in skeletal muscle.

Effect of pyruvate, octanoate and glucose on leucine degradation in skeletal muscle from fed and fasted chicks

1. Pyruvate at 5 mM decreased the rate of leucine oxidative decarboxylation and increased the rate of 2-oxoisocaproate production in extensor digitorum communis (EDC) muscles from both fed and 24-hr fasted chicks. Pyruvate at 5 mM increased the net rate of leucine transamination in EDC muscle from fed chicks and had no effect in EDC muscles from 24-hr fasted chicks. 2. Octanoate at 0.2 and 1 mM markedly increased the rates of net leucine transamination, leucine oxidative decarboxylation and oxidation of decarboxylated leucine carbons 2-6 in EDC muscles from fed chicks, but had no effect on these parameters of leucine degradation in muscles from 24-hr fasted chicks. 3. Glucose at 5 and 12 mM decreased the rates of leucine oxidative decarboxylation and oxidation of decarboxylated leucine carbons 2-6, and increased the net rate of 2-oxoisocaproate production as compared to control (no glucose) group in muscles from fed chicks. Glucose had no effect on these parameters of leucine degradation in muscles from 24-hr fasted chicks.

Diamond-dusted microspatula tips for vitreoretinal surgery

We have developed a microsurgical spatula set consisting of four different tips and a universal handle. The set offers a range of tip angulation of 30 degrees, 45 degrees, 60 degrees, and 80 degrees. The bottom surfaces of the spatula tips are covered with fine diamond dust. The 30 degrees tip has a blunt and tapered end. All tips can be introduced through a conventional 20-gauge sclerotomy in a pars plana vitrectomy. The tips fit on a universal handle. The set has been used as a complement to vitreous forceps in dissecting and removing preretinal membrane.

Ketone bodies inhibit leucine degradation in chick skeletal muscle

1. DL-beta-hydroxybutyrate (4 mM) increased the net rate of leucine transamination and the net rate of 2-oxoisocaproate (KIC) production in extensor digitorum communis muscles from fed chicks. 2. DL-beta-hydroxybutyrate at 1 and 4 mM inhibited leucine oxidative decarboxylation in muscles from fed chicks. 3. Acetoacetate at 1 and 4 mM inhibited leucine oxidative decarboxylation and total leucine oxidation, but increased net KIC production in muscles from fed chicks. 4. Both DL-beta-hydroxybutyrate and acetoacetate at 1 and 4 mM inhibited the net rate of leucine transamination and the rates of leucine oxidative decarboxylation and total leucine oxidation in muscles from 24-hr fasted chicks.

Sorbents used for removal of urea in the system of artificial kidney

Three copolymers were made from the suspension polymerization of methyl acrylate, divinyl benzene and triallyl isocyanurate; acrylamide and N,N'-methylene-bis-acrylamide; and styrene and divinyl benzene. These copolymers were then converted into derivatives of hydrazides through several steps. They were used as polymeric sorbents. They sorbed in situ a little bit less than 40 mg. of urea per gram of sorbent at 37 degrees C, pH = 7.0-7.4 and the percentage of urea in the buffer solution being 130 mg%. The sorption of urea was related to the specific surface area of the sorbent, temperature of sorption and time of sorption, concentration of urea, pH value of solution etc. In order to find out whether the above-prepared derivatives of hydrazide can be used clinically as polymeric sorbents in artificial kidney system, the junior author carried out experiments with patient's dialysate as imitated to hemodialysis. From the results, it indicates the sorbents might be used in artificial kidney system because they sorbed the urea from hemodialysate as much as that of the pure urea in a buffer solution.

The efficacy and adequacy of continuous ambulatory peritoneal dialysis

Since it was introduced in 1976, continuous ambulatory peritoneal dialysis (CAPD) has won acceptance in many centres and it is now regarded as an important alternative to haemodialysis. CAPD patients have comparable and, in some circumstances, better survival than those on chronic haemodialysis. It is indicated particularly in patients with diabetes mellitus, cardiovascular instability and at the extremes of life. The success of kidney transplantation is similar in those maintained on CAPD and on haemodialysis. CAPD also achieves satisfactory physical and psychological rehabilitation, and the quality of life, including the level of sexual function, is similar during CAPD and haemodialysis. Women on CAPD menstruate more often than those on haemodialysis. CAPD provides adequate clearance of metabolic wastes, maintains fluid balance and ameliorates neurotoxic cognitive dysfunction. CAPD gives control of hypertension and anaemia which is superior to that on haemodialysis. Neuropathy remains stable but osteitis fibrosa seems to progress. CAPD is the most economical of the various forms of dialysis. We conclude that CAPD is an adequate form of replacement and should be made available in every nephrology centre providing treatment for patients with end-stage renal disease.

Spontaneous remission of nephrotic syndrome in IgA glomerular disease

We report two cases of adult onset nephrotic syndrome with pathologic features of minimal change disease but a predominance of IgA in mesangial regions. Both cases underwent spontaneous remission despite an episode of recurrent nephrotic syndrome in one patient. The relationship of the glomerular disease to minimal change and IgA nephritis is discussed.

A carrier state of X-linked juvenile retinoschisis

The carrier state of X-linked juvenile retinoschisis has not been known to be associated with any fundus abnormalities. We report a case where there are funduscopic changes and mild visual acuity changes in one eye of a carrier.