Retinitis pigmentosa associated with hearing loss, thyroid disease, vitiligo, and alopecia areata: retinitis pigmentosa and vitiligo

A 54-year-old woman with retinitis pigmentosa and hearing loss developed white skin patches that were subsequently diagnosed as vitiligo. A review of the literature reveals that, although the association of vitiligo with various tapedoretinal degenerations has been reported on several occasions, the association with typical retinitis pigmentosa is quite rare. This combination of disorders associated with pigment loss is of interest as immunologic disturbances have been implicated on both.

Plasma disappearance and biliary excretion of bromosulfophthalein in styrene-treated and styrene oxide-treated rats

Treatment with a single ip dose of styrene (908 mg/kg) 5 h before iv injection of bromosulfophthalein (BSP) (50 mg/kg) in rats resulted in (1) a decrease (approximately 30%) in biliary flow during 10-25 min but an increase in such flow during 60-90 min after the BSP dose, (2) a delay in cumulative excretion (approximately 50%) of BSP in bile during 5-60 min (but the latter became close to the control value after 75 min, and (3) no change in plasma disappearance of BSP. The first two effects seemed to depend on the dose of styrene. After pretreatment (2 h) with styrene oxide (375 mg/kg ip), a greater diminution of bile flow (approximately 50%) and of cumulative excretion of BSP was observed during the entire 5-90 min of bile collection after BSP administration, but the plasma disappearance of BSP remained unaffected. These results suggest that intrahepatic metabolism (and not hepatic uptake) of BSP and/or its transport from liver to bile are impaired after styrene- or styrene oxide-induced liver injury.

Effects of microsomal induction and inhibition on styrene-induced acute hepatotoxicity in rats

Administration of a single high dose of styrene (878 mg/kg ip in corn oil) to young male rats produced significant elevations in the activities of serum transaminases: 230, 209, and 71% increases in the activity of serum glutamic-oxaloacetic transaminase (SGOT) and 163, 437, and 227% in that of serum glutamic-pyruvic transaminase (SGPT) at 2, 6, and 24 h, respectively, after the dose. These results demonstrated that styrene could produce acute hepatic injury in young rats. Urinary nonprotein sulfhydryl contents and mandelic, phenylglyoxylic, and hippuric acids were all increased. Pretreatment of rats with phenobarbital and 3-methylcholanthrene did not further enhance the activities of SGOT and SGPT after styrene, but produced changes in other biochemical parameters, for example, an increase in liver weight, decrease in serum albumin and globulin concentrations, increase in serum alkaline phosphatase activity at 2 and 6 h, and increase in urinary urobilinogen concentrations. In addition, such pretreatments further increased the nonprotein sulfhydryl contents at 2 and 6 h after styrene injection. Pretreatment of rats with the microsomal enzyme inhibitor SKF 525-A failed to prevent the hepatotoxicity induced by styrene and did not modify the overall urinary excretion profiles of styrene metabolites. This study suggests that the mechanism of the activation/deactivation process leading to the metabolism and hepatotoxicity of styrene is complex and that alternative pathways not dependent on cytochrome P-450 might also be involved.

Metabolism and acute hepatotoxicity of styrene oxide in rats

The metabolism and acute hepatotoxicity of styrene oxide were studied after ip administration of a high dose of 375 mg/kg to adult male rats. Liver glutathione was significantly depleted at 2 h, but became normal at 6 h. The activity of serum glutamic-oxaloacetic transaminase was increased during the entire period (24 h) of study, while the activities of alkaline phosphatase and serum glutamic-pyruvic transaminase were elevated at 2 and 24 h, respectively, after administration of the dose. Decreased body weights and increased liver weights were observed at 24 h. Both prothrombin time and urinary urobilinogen concentration were temporarily increased. While urinary mandelic and phenylglyoxylic acids were increased during the entire time period, urinary (but no fecal) nonprotein sulfhydryl contents were increased at 2 and 6 h. The results of biochemical tests of liver function suggest a mild liver pattern in rats treated acutely with styrene oxide.

Influence of free fatty acid anion on the binding of warfarin to cytoplasmic proteins from rat liver

In vitro binding studies have shown that warfarin binds strongly to both ligandins (Y) and Z protein obtained from rat liver cytosol with dissociation constants of 11.7 and 10.1 microM respectively. Increasing concentrations of oleate ion significantly increased the dissociation constant of warfarin with either protein, whereas laurate ion showed the same behavior only with Z protein. On the other hand, the binding of warfarin to liver cytoplasmic proteins in vivo was decreased in 72-h-pre-fasted rats, although such fasting failed to produce any increase in the in vivo levels of the cytoplasmic free fatty acids (FFA). However, based on the results of the in vitro binding study, it is suggested that changes in the composition of hepatic cytoplasmic free fatty acids as a result of fasting could reduce the in vivo binding of warfarin to Y and Z proteins and hence could lead to an increase of unbound warfarin in liver cytosol.

Bioavailability of phenytoin in dogs: effect of crystal form and particle size

Significant differences in bioavailability were observed in dogs when phenytoin crystals of different particle size were administered. No significant differences in bioavailability were observed when different crystal forms were compared.

The association of neurofibromatosis and hyperparathyroidism

Two patients with coexisting neurofibromatosis and hyperparathyroidism are described, bringing the total number of such cases in the world literature to seven. Other more classic examples of the association of tumorous conditions of neuroectodermal and entodermal origin are discussed to support the suggestion that the association of these two diseases may be another variant of multiple endocrine neoplasia type 2 (MEN2b). It may be clinically profitable to investigate all patients with either disease in order to uncover their coexistence.

Effect of free fatty acid anion on the in vitro binding of 1-anilino-8-naphthalene sulfonate to cytoplasmic proteins from rat liver

The influence of oleate ion, a free fatty acid anion, on the binding characteristics of 1-anilino-8-naphthalene sulfonate (ANS) with the cytoplasmic proteins (Y and Z) from rat liver has been examined using fluorescence spectroscopy. ANS binds strongly with both ligandin (Y) and Z protein at a single binding site with dissociation constants of 0.6 and 1.4 micron respectively. Increasing concentrations of oleate ion decreased the ANS binding with either protein by competing with the ANS binding site. Relative binding constant of oleate ion for the hepatic ligandin or Z protein was about 2 micron as determined from the competitive inhibition of ANS binding. These results suggest that variations in the hepatic cytoplasmic free fatty acid concentration may be important in regulating the capacity of Y and Z proteins to transport other organic anions.

Stable and transmissible dicentric chromosome with terminal centromeres in ascites cell of mouse sarcoma 180

The occurrence of a stable and transmissible dicentric chromosome with 2 terminal centromers has been reported in the ascites form of mouse sarcoma 180 cells which is chromosomally hypotetraploid. The number of such dicentrics is 2 in all endoreduplicated cells. The probable mode of anaphase separation of the dicentric has been discussed.

Studies on the crystalline form of phenytoin

Two crystalline forms of phenytoin were isolated and characterized by X-ray diffraction, IR spectroscopy and differential thermal analysis. The dissolution behavior of the two forms was determined in water. The crystals of needle shape (form II) were found to exhibit slower dissolution rate than the other crystal form (form I).

Robertsonian fusion leading to the formation of stable dicentric chromosome in an ascites cell line of the mouse

The dicentric nature of a marker metacentric chromosome originated by robertsonian fusion has been established in the ascites cells of mouse sarcoma 180. C-banding analysis has revealed that the metacentric is actually a dicentric with 2 closely situated C-positive heterochromatic zones. The nature of the centromeres and the NF value of the cell indicate that this meta-dicentric marker has originated by breakage and fusion within each of the short arms of 2 acrocentric chromosomes.

Pentazocine suppositories for post-operative pain: intramuscular pentazocine injections versus suppositories in a controlled trial in 588 patients

A between-patient comparison of the analgesic effect of pentazocine 50 mg by suppository and 30--45 mg by intramuscular injection was made in 558 postoperative patients, 54% within 24 hours of operation. The suppositories proved acceptable overall, even though effectiveness was less at half an hour after administration (particularly in those patients with severe initial pain) and there was greater need for further analgesia at one hour. The cost of treatment with suppositories is less than with injections. After the suppositories there were half as many patients asleep at one hour than after injections, and fewer possible side-effects (7 compared to 24).

Spontaneour Robertsonian fusion leading to karyotype variation in the house mouse - first report form Asia

The occurrence of spontaneous Robertsonian fusion leading to 2n=39 chromosomes (NF=40) in the house mouse (Mus musculus domesticus) has been reported for the first time from Asia. 3 phenotypically normal female mice collected from 2 distantly located populations of India (Tripura and Calcutta) show centric fusion in somatic chromosomes between pairs 2 and 16, and 8 and 14 respectively. C-banding analysis revealed that the (sub)metacentric has been originated by fusion between the broken/eroded centromeres of 2 telocentric chromosomes.

The influence of fasting on the disposition of warfarin in rats

A study was undertaken to investigate the influence of fasting on the disposition of warfarin in rats. Fasting consisted of withholding solid food, but not water, immediately following warfarin (3 or 10 mg/kg s.c.) administration until sacrifice at different time intervals (3, 6, 12, 24 and 30 hours). Control animals were fed ad libitum. Total and unbound warfarin concentrations were measured in plasma and liver supernatant as well as unchanged warfarin and its metabolites in urine. The disposition of unbound warfarin was found to be markedly affected by fasting, especially at the 3 mg/kg dose: the disappearance rate of unbound warfarin from plasma was accelerated in fasted animals in contrast to that of total warfarin. In addition, unbound warfarin was cleared from plasma at a more rapid rate than total warfarin in both control and fasted animals. At the 10 mg/kg dose, the disposition of total and unbound warfarin was little affected by fasting. The concentration of unbound warfarin in the liver supernatant of fasted rats given warfarin, 3 mg/kg, was significantly increased at 6 and 24 hours of fasting. Plasma free fatty acids were significantly elevated starting at 6 hours, but no such difference was noticed with liver homogenate, except at 24 hours. The 24-hour urinary excretion of unchanged warfarin was higher in fasted rats, but fasting failed to produce any change in the excretion of warfarin metabolites. The results of the present investigation indicate that short periods of fasting influence the disposition of unbound warfarin without apparently modifying its biotransformation and further show the importance of plasma protein binding on the pharmacokinetics of warfarin.

The influence of fasting and stress on the response of rats to warfarin

A study was undertaken to investigate the influence of fasting (24 hours), epinephrine (four 0.25 mg/kg s.c. doses at hourly intervals), adrenocorticotropin (two 40 I.U. s.c. doses at 2-hour intervals) and immobilization stress (4 hours) on the response of rats to some coumarin or indanedione anticoagulants. The anticoagulants were always administered first and were followed immediately or within the next hour by the appropriate challenge. Fasting produced a significant enhancement of the antiprothrombin response to warfarin (0.5 mg/kg i.v. or 0.75-3.0 mg/kg s.c.), bishydroxycoumarin (7.5 mg/kg i.p. or 10 mg/kg s.c.) and phenindione (40 mg/kg p.o). Epinephrine and immobilization stress, but not adrenocorticotropin, similarly prolonged the prothrombin time after warfarin (0.75-3.0 mg/kg s.c.). When used in the absence of anticoagulants, all challenges had no effect on the prothrombin time. In addition, fasting did not affect the response of anticoagulated animals to vitamin K. Plasma free fatty acids were significantly increased by the various challenges. The binding constant of warfarin to undiluted plasma proteins were decreased from the control value by a factor of 1.7 and 2.0 as a result of immobilization stress and fasting, respectively. Fasting per se increased the amount of bound endogenous free fatty acids per mole of protein; the latter parameter was further increased in the presence of warfarin. The present data show that fasting and stress enhance the anticoagulant response to warfarin and suggest that this might be due to an interference of endogenous free fatty acids with binding of warfarin to plasma proteins.

Growth of bacteriophages MS2 and T7 on streptomycin-resistant mutants of Escherichia coli

Streptomycin-resistant mutants of an Hfr strain of Escherichia coli K were examined for their ability to support the growth of male-specific ribonucleic acid phage MS2 and female-specific deoxyribonucleic acid phage T7. Normally, the Hfr strain allows propagation of MS2 and is lysed by it (efficiency of plating equal to 1), whereas the same strain restricts propagation of T7 and is not lysed by it (efficiency of plating smaller than 10-7). Twenty-four isolates out of 26 independently obtained streptomycin-resistant mutants are partially or completely derestricted for propagation of T7; efficiency of plating of T7 in such strains ranges from 10-3-1. Depending on their response to plating of MS2 and T7, the streptomycin-resistant mutants can be divided into four classes. The mutants in all four classes continue to be "male" in conjugation with F- strains. Genetic analysis is presented to show that restriction of MS2, derestriction of T7, and resistance to streptomycin are the pleiotropic effects of a single mutation at the strA locus.