Use of quaternized cassia galactomannan for hair conditioning.

There is a continuing need for hair care formulas to deliver superior conditioning benefits with highly efficient deposition of hair-enhancing components. In this paper, we describe high-charge-density (3.0 mEq/g) cassia hydroxypropyltrimonium chloride (cassia HPTC), a quaternized galactomannan from the endosperm of Cassia tora and Cassia obtusifolia. Cassia HPTC is shown to participate in the coacervate phase of conditioning shampoos, from which it is deposited onto hair to provide conditioning benefits. Cryo-scanning electron microscopy and time-of-flight secondary ion mass spectrometry were used to observe and characterize the cassia HPTC deposits left on hair. The high-charge-density cassia HPTC resulted in improved deposition efficiency compared with a quaternized guar-containing formula. Cassia HPTC offers benefits as an alternative to traditional cationic polymers as conditioning agents or as an adjunct conditioner to decrease the amount of cationic polymer needed to achieve the desired conditioning performance.

Calibration of new high dose rate 192Ir sources.

The increased popularity of high dose rate (HDR) brachytherapy in the treatment of neoplastic disease has resulted in the introduction of new or redesigned 192Ir sources by various manufacturers. In order to provide accurate clinical dosimetry, accurate calibration of these sources is required. In this work, two new sources are calibrated with the standard, NIST traceable, in-air calibration technique. These sources are the Varian VariSource (VS2000) and the newly redesigned Nucletron MicroSelectron source. An uncertainty budget was performed to determine the overall uncertainty of the measurement, and a total relative expanded uncertainty (k = 2) of 2.15% was calculated. The results of the source calibration using the in-air technique and that obtained based upon the 1991 standard calibration all lie well within this uncertainty. In addition to the in-air calibration, contact autoradiographs of the sources were made with International Specialty Products model HD810 radiochromic film to demonstrate the sources relative dose distributions.

Histologic evaluation of the inflammatory response around implanted hollow fiber membranes.

Hollow fiber membranes are enjoying widespread use as barrier materials in many implanted applications. In order to predict in vivo device behavior, it is important to understand and quantify the changes to the membrane and to the tissue immediately surrounding it that occur following implantation. We have considered a range of commercially available hollow fiber membranes for their suitability as candidates for subcutaneously implanted applications. Through analysis of excised tissue sections by light microscopy, membranes were screened at 3, 6, and 12 weeks post-implantation for the ability to maintain integrity, foreign-body reaction, and thickness of the external fibrotic capsule layer. The polysulfone microfiltration membranes and cellulose diacetate membranes investigated were found to be unsuitable owing to extensive degradation. All membranes exhibited typical foreign body reaction with fibrotic capsule formation. The thinnest capsules were observed on the regenerated cellulose microdialysis membranes and the polysulfone ultrafiltration membranes. Extensive cellular penetration into the membrane matrix of the latter was observed, but did not appear to affect the foreign body reaction. A heat-sealing method was also considered for thermoplastic membranes and found to effectively prevent cellular penetration into the lumen of the hollow fiber for the duration of the 12-week implantation.

Isoflurane anesthesia in the African clawed frog (Xenopus laevis).

Isoflurane is one of the safest and most accepted anesthetic agents for reptiles, birds, and mammals. It has also been used in terrestrial amphibians. The use of inhalation agents in an entirely aquatic frog presents a new dilemma for delivery in contrast to terrestrial species. The African Clawed Frog respires by using both transcutaneous gas exchange and air breathing. These frogs remain submerged for long periods of time, thus making standard inhalation techniques impractical. We tested five methods for delivering isoflurane: 1) bubbling isoflurane and oxygen in the water, 2) intracoelomic injection, 3) subcutaneous injection, 4) intramuscular injection, and 5) topical application. For the topical application, we developed a simple technique by using an absorptive pad with a vapor-barrier backing, saturating the pad with the liquid isoflurane, and placing the pad on the back of the frog while it was confined in a plastic bowl. Although two of the three injectable routes induced anesthesia, only the topical route produced rapid induction with consistent, safe recovery. Bubbling isoflurane with oxygen into water was unsuccessful. Topical application of isoflurane was most successful and appears to be a safe and practical method that can be used as an alternative to tricaine methylsulphonate, hypothermia, or other methods for anesthetizing African Clawed Frogs.

Toxicity of the novel animal-derived anticancer agent, VRCTC-310: acute and subchronic studies in beagle dogs.

Acute and subchronic toxicities of VRCTC-310, a combination product of crotoxin (CT) and cardiotoxin (CD), which has shown antitumor activity in vivo, have been studied in Beagle dogs. Single i.m. doses of 0.25, 0.5 and 1.0 mg/kg resulted in dose-dependent local muscular toxicity consisting of myofiber atrophy, interstitial edema and macrophage infiltration. Also, AST, ALT and LDH levels increased on day 2, returning to normal values on days 6-8. Local lesions were absent after recovery on day 45. At 2.0 mg/kg, signs of neurotoxicity (ataxia) appeared, in addition to vomitus, salivation, hematuria and myotoxicity in tongue and diaphragm on day 8. Local lesions healed with fibrosis at the site of injection on day 45. Administration of fixed (0.025 and 0.05 mg/kg) or escalating (0.025-0.1 mg/kg) daily doses for 30 days also produced local muscular damage, which was absent at day 75. The increases in AST, ALT and LDH serum activities on days 2-4 were independent of dosing schedule and sharply decreased on day 8, despite continuation of treatment. An escalating dose schedule of 0.025-2.0 mg/kg showed local muscle damage at the site of injection on day 31, however, there were no lesions of myotoxicity in the tongue or diaphragm and no clinical signs of neurotoxicity were observed. Animals tolerated the subchronic treatment better than the acute. The resolution of serum enzymes to normal values during treatment may be attributed to a decrease of sensitivity to VRCTC-310-mediated myotoxic effects.

Plasmodium berghei: production and quantitation of hepatic stages derived from irradiated sporozoites in rats and mice.

Immunization with irradiated-attenuated malaria sporozoites has been shown to protect both rodents and humans against a homologous sporozoite challenge. Irradiated-attenuated sporozoites retain their capacity to invade hepatocytes and transform into trophozoites without undergoing complete schizogony. As a result, the minute size of these trophozoites (4-8 microns) makes their detection by conventional microscopy difficult. An additional problem lies in obtaining sufficient quantities of exoerythrocytic stages of attenuated parasites in vivo to study their antigenic repertoire and the sequence of events that occur after immunization of hosts. We have used a previously described method of inoculating Plasmodium berghei sporozoites directly into specific liver lobes (HPBI = hepatic portal branch inoculation) to improve parasite yields. Comparing HPBI with tail vein inoculation of sporozoites in Brown Norway rats and C57BL/6 mice revealed up to a 6-fold increase in hepatic parasite yields by HPBI method. The inoculation of 3 x 10(6) irradiated sporozoites via HPBI yielded 139 +/- 2 and 69 +/- 2 exoerythrocytic parasites per cm2 of liver in Brown Norway rats and C57BL/6 mice, respectively. The HPBI method therefore not only facilitates visualization of a large number of irradiated hepatic stage parasites within the defined lobes of the liver but also provides ample numbers of parasites for immunization and for immunological analysis.

Binding of tritiated yohimbine to platelets in women with maternity blues.

Platelet alpha 2-adrenoceptor binding was measured in 108 women in the 36th week of pregnancy, at ten and twenty days and at three and six months post-partum. An age matched non-pregnant control group of women (N = 25) was also studied. The number (Bmax) of alpha 2-adrenoceptors was elevated antepartum but fell to control values on the tenth post-partum day. At three and six months post-partum, however, alpha 2-adrenoceptor Bmax was again increased. Women who developed maternity blues (N = 59) had significantly more platelet alpha 2-adrenoceptors than those who did not (N = 49) at both ten and twenty days post-partum. In addition their alpha 2-adrenoceptor Bmax was greater than controls at all time points measured except the tenth post-partum day. In contrast, the alpha 2-adrenoceptor Bmax of women without the blues did not differ from controls at any stage. It is suggested that women who develop maternity blues may have a relatively enduring abnormality in alpha 2-adrenoceptor sensitivity which is associated with psychological symptoms when concentrations of circulating sex-steroids suddenly change.

Pancreatectomized swine as a model of diabetes mellitus.

The development of a model of diabetes mellitus using swine offers the potential for new investigations in the study of human diabetic complications. In particular, animal models for the study of accelerated atherosclerosis associated with diabetes are important and presently lacking. Swine were selected because they have a natural susceptibility to atherosclerosis and have plasma lipoprotein patterns which are close to those of humans. Diabetes mellitus was induced in nine miniature swine by total pancreatectomy. Following surgery, they were maintained on porcine derived insulin at doses predicated on blood glucose levels. Pancreatic enzymes were replaced by dietary supplementation. Eight of the nine pigs were pancreatectomized successfully and stabilized with insulin. After initial weight loss, the pancreatectomized pigs maintained growth rates comparable to controls. Hypoglycemia and bacterial infections were the major problems experienced. Post-operative survival ranged from 50 days to 455 days. Our study shows that swine can be pancreatectomized successfully and maintained as insulin dependent animals, presenting a realistic model for research on the complications of diabetes.

Dieting and weight loss in volunteers increases the number of alpha 2-adrenoceptors and 5-HT receptors on blood platelets without effect on [3H]imipramine binding.

Platelet monoamine receptor binding was determined in normal male and female subjects before and at the end of a 2- to 3-week weight reducing diet (1200 kcal daily). Dieting was associated with an increase in platelet binding sites for both [3H]yohimbine and [125I]iodolysergic acid diethylamide (iodoLSD). The affinity at the platelet [125I]iodoLSD binding site was reduced. In contrast, [3H]imipramine binding was unchanged. These results have important implications for studies that employ platelet binding as a peripheral marker of neurotransmitter function in psychiatric illness.

Binding of yohimbine and imipramine to platelets in depressive illness.

Radioligand binding to intact platelets was carried out in antidepressant-free patients and the 1 mg dexamethasone suppression test (DST) was performed. There were no differences in binding characteristics between patients and controls for either [3H]yohimbine or [3H]imipramine. There were no differences in binding between patients classified as endogenous using the Newcastle Scale, compared with non-endogenous patients, and no difference between DST suppressors and non-suppressors. The severity of depression did not affect binding values. After 4-6 weeks antidepressant treatment [3H]yohimbine binding was significantly reduced but [3H]imipramine binding was unaffected.

A comparison of alpha 2-adrenoreceptor binding characteristics of intact human platelets identified by [3H]-yohimbine and [3H]-dihydroergocryptine.

The binding characteristics of [3H]-yohimbine on intact human platelets were investigated and compared to those of [3H]-dihydroergocryptine. A significant correlation (r = 0.92, P less than 0.01, n = 7) was observed between the inhibition of [3H]-yohimbine binding and of noradrenaline-induced platelet aggregation, indicating that [3H]-yohimbine binds to the alpha 2-adrenoreceptor responsible for noradrenaline-induced platelet aggregation. The binding capacity of [3H]-yohimbine in 20 young male volunteers was 39 +/- 2.2 fmol/10(8) platelets (mean +/- s.e.m.). This is considerably lower than the binding capacity of [3H]-dihydroergocryptine previously reported. Simultaneous analysis of [3H]-yohimbine and [3H]-dihydroergocryptine binding in 10 subjects showed a significantly lower binding capacity for [3H]-yohimbine (P less than 0.001, paired t-test). This difference was not present in every subject, and was consistent within individuals on repeated testing. Possible causes of this difference in radioligand binding are discussed.

Changes in platelet alpha 2-adrenoceptor binding post partum: possible relation to maternity blues.

Platelet alpha 2-adrenoceptor binding characteristics were investigated in 28 healthy women during the peripartum period. The number of platelet alpha 2-adrenoceptors fell after childbirth, corresponding to a fall in the circulating levels of oestrogen and progesterone. Two-thirds of the women had an episode of maternity blues. At 7-10 days post partum the platelet alpha 2-adrenoceptor capacity in these subjects was significantly higher than in those women who did not show signs of maternity blues and significantly higher than a control group of normally menstruating women. We conclude that platelet alpha 2-adrenoceptors may be affected by the circulating levels of endogenous oestrogen and progesterone and that a delayed or diminished fall in platelet alpha 2-adrenoceptor capacity after childbirth may be associated with the development of maternity blues.

Escherichia coli DNA polymerase I. Sequence characterization and secondary structure prediction.

The primary sequence of DNA polymerase I from Escherichia coli K12 as derived from the DNA sequence (Joyce, C. M., Kelley, W. S., and Grindley, N. D. F. (1982) J. Biol. Chem. 257, 1958-1964) has been verified. Protein sequencing through eight cycles of the Klenow large fragment yields a unique sequence corresponding to residues 324 to 331 from the translated DNA sequence and defines the subtilisin cleavage site for formation of the large and small fragments as Thr323-Val324. Site-specific cleavage of whole enzyme and large fragment at cysteines and sizing of the resulting fragments verify the location of the two cysteines at residues 262 and 907 as assigned by the DNA sequencing. Isolation of tryptic peptides derived from DNA polymerase I yielded unique peptides whose composition exactly corresponded to theoretical tryptic peptides derived from the translated DNA sequence. Identification of the expected carboxyl-terminal tryptic peptide and carboxypeptidase digestion of whole enzyme and large fragment confirm histidine-928 as the carboxylterminus. A secondary structure prediction is made using the available primary sequence data. The model contains 43% alpha helix, 17% beta-structure, 58 beta-turns, and several interesting super-secondary structure elements.

A rapid procedure for isolation of large quantities of Escherichia coli DNA polymerase I utilizing a lambdapolA transducing phage.

DNA polymerase I produced by infection of Escherichia coli K12 with the specialized transducing phage lambdapolA has been purified by a simplified procedure and shown to be identical with the enzyme produced by uninfected E. coli in all aspects which have been examined. The abundance of the enzyme in infected cells and the ease with which it may be purified will simplify the study of the enzyme's physical and chemical characteristics. In addition, the enzyme is now much more readily available for use as an analytical tool in nucleic acid sequence and structure studies.