Absorbance changes of carotenoids in different solvents

Carotenoids are typically measured in tissues with the high performance liquid chromatography (HPLC) and quantitation is usually done by calibrating with stock solutions in solvents. Four carotenoids including lutein, zeaxanthin, lycopene and beta-carotene were dissolved in hexane and methanol respectively, and their absorbance characteristics were compared. Lutein shows absorbance spectra that are almost independent of solvents at various concentrations. Spectra of zeaxanthin, lycopene and beta-carotene were found to be more solvent-dependent. The absorbance of zeaxanthin at lambda max is about approximately 2 times larger in methanol than in hexane at the higher concentrations, and increased non-linearly with increasing concentration in hexane. The absorbance of lycopene at lambda max in hexane is approximately 4 fold larger than in methanol, but the absorbance of the methanol sample can be recovered by re-extracting this sample in hexane. The absorbance of beta-carotene in hexane is larger than in methanol, and increased linearly with increasing concentration. But beta-carotene showed a non-linear concentration effect in methanol. There are very small variations in lambda max for all four carotenoids between hexane and methanol, due to differences in molar extinction coefficients. The non-linear concentration effects for these carotenoids are probably due to differences in solubility leading to the formation of microcrystals. Thus, care should be taken with quantitation of tissue carotenoid values, when they depend on measurement of concentrations in stock solutions.     

Central nervous system abscesses due to Coccidioides species

The internalization of basic fibroblast growth factor (FGF-2) was studied in Chinese hamster lung fibroblasts (CCL39). Recombinant FGF-2 was derivatized with a photoactivable agent, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB), iodinated, and used to visualize intracellular FGF-2-affinity-labeled molecules after internalization at 37 degrees C. Iodinated HSAB-FGF-2 maintained the properties of natural FGF-2 such as affinity for heparin, binding to Bek and Fig receptors, interaction with high- and low-affinity binding sites, and reinitiating of DNA synthesis in CCL39 cells. Affinity-labeling experiments at 4 degrees C with 125I-HSAB-FGF-2 led to the detection of several FGF-cell surface complexes with apparent molecular mass of 80, 100, 125, 150, 170-180, 220, 260, and about 320 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), whereas two specific bands at 80 and 130-160 kDa were obtained using the homobifunctional cross-linking reagent, disuccinimidyl suberate. When the cells, preincubated with 125I-HSAB-FGF-2 at 4 degrees C and then washed, were shifted to 37 degrees C, irradiation of the internalized labeled FGF-2 led to detection of a similar but fainted profile with one major specific band at 80 kDa. Heparitinase II treatment of the cells reduced binding of 125I-HSAB-FGF-2 to its cell surface sites by 80% and internalization by 55%, indicating the involvement of heparan sulfate proteoglycans in these processes. Among the heparitinase-sensitive bands was the 80-kDa complex.     

Strengthening of composites due to microstructural changes in the matrix

The addition of discontinuous silicon carbide (SiC) to aluminum (Al) alloys can result in a five-fold increase in the yield stress. The magnitude of the increase is obviously a function of the volume fraction and the particle size of the SiC. Previously, it was proposed that the strength increase due to SiC addition to Al alloys was the result of change in the matrix strength, i.e. an increase in dislocation density and a reduction of subgrain size. The data obtained from a series of experiments indicate that dislocation density increases with an increase in volume fraction of SiC and decreases with an increase in particle size. The subgrain size decreases as the volume fraction increases and increases as the particle size increases. There is a good correlation between the microstructural changes in the matrix and the changes in the yield stress of the composites.     

Specific changes of the uterine cervix due to contraceptives]

A group of 344 cervices, produced by conisation within a period of 5 1/2 years, were examined for specific effects of contraceptives. In half of all women, who used oral contraceptives, specific lesions such as "siebartige polypoide Hyperplasie" (cribriform polypoid hyperplasia) were found. The findings and their etiology and importance are discussed.     

Persistent cutaneous larva migrans due to Ancylostoma species

Cutaneous larva migrans is considered to be a self-limited parasitic infection of about 2 to 8 weeks' duration, though it has been reported to persist for as long as 55 weeks. In this case, a healthy 47-year-old white man had multiple serpiginous lesions typical of cutaneous larva migrans for 18 months. A biopsy taken 2 months before presentation showed a parasite consistent with Ancylostoma species deep in a hair follicle. The patient initially responded to topical thiabendazole, but relapse occurred when therapy was discontinued. Oral thiabendazole cured the problem after 22 months of infestation. Cutaneous larva migrans may sometimes be long-standing, here almost 2 years, even in a healthy patient. Organisms may reside deep in the hair follicles. Topical thiabendazole may not penetrate to this depth, necessitating oral thiabendazole therapy.     

Magnetic field changes in the human brain due to swallowing or speaking

Urologists enjoying the protection of the law owe a duty to participate in the legal system as expert witnesses. Forensic education has been neglected by clinical educators. Qualification of experts includes forensic as well as clinical competence. The forensic urologist must know legal concepts and language; the powers, duties, and role of courtroom experts. The expert witness' role is to factually enlighten the judges, not to persuade them. Practical measures to remedy the current state of affairs are described from over a decade of experience. These practical measures should be supplemented by the formal development of a subspecialty of Forensic Urology sponsored by our colleges and professional societies.     

Miscibility gap due to ordering in the BCC Fe-Ge system

Phase equilibria in the bcc Fe-Ge system have been investigated by means of electron probe microanalysis and transmission electron microscopy. Two kinds of ordered phases, B2 and DO₃ types, have been detected, the B2 phase being formed from the disordered A2 phase by a 2nd order transition. The DO₃ phase is also formed from the B2 phase by a 2nd or higher order transition at higher temperatures. Below about 820 °C, however, the transition becomes a 1st order, and a miscibility gap between these ordered phases occurs in the composition range from 13 to 16 at. pct Ge. It has been also confirmed that the solubility of Ge in the bec phase shows a retrogression due to the formation of DO₃ phase. On the basis of these experimental results, the phase diagram for the Fe-Ge system has been partly revised.     

Miscibility gap due to ordering in the BCC Fe-Ge system

Metallurgical and Materials Transactions A - Phase equilibria in the bcc Fe-Ge system have been investigated by means of electron probe microanalysis and transmission electron microscopy. Two kinds...     

Miscibility gap due to ordering in the BCC Fe-Ge system

Phase equilibria in the bcc Fe-Ge system have been investigated by means of electron probe microanalysis and transmission electron microscopy. Two kinds of ordered phases, B2 and DO₃ types, have been detected, the B2 phase being formed from the disordered A2 phase by a 2nd order transition. The DO₃ phase is also formed from the B2 phase by a 2nd or higher order transition at higher temperatures. Below about 820 °C, however, the transition becomes a 1st order, and a miscibility gap between these ordered phases occurs in the composition range from 13 to 16 at. pct Ge. It has been also confirmed that the solubility of Ge in the bec phase shows a retrogression due to the formation of DO₃ phase. On the basis of these experimental results, the phase diagram for the Fe-Ge system has been partly revised.     

Thylakoid protein phosphorylation in evolutionally divergent species with oxygenic photosynthesis

A 32-year-old, previously healthy woman with a diffuse, complex tumoral process is described. While she was being evaluated for primary infertility, a laparoscopic procedure revealed a disseminated peritoneal process associated with bilateral ovarian lesions. A clinical diagnosis of stage III ovarian cancer was made and total hysterectomy, bilateral salpingo-oophorectomy, and omentectomy were performed. Pathologic studies showed an admixture of leiomyomatosis peritonealis disseminata (LPD) endometriosis, and an extensive multicystic mesothelial proliferation. Although endometriosis is known to occur in conjunction with either LPD or multicystic mesothelioma, to our knowledge this is the first report of all three lesions occurring simultaneously.     

Dislocation boundary width changes due to cyclic hardening

In this article, cyclic deformations of pure aluminum specimens were characterized by analyzing the cyclic hardening response. Microstructural observations were done by means of transmission electron microscopy (TEM). Microscopic analysis showed that dislocation tangles migrate to the boundary and dislocation boundaries become thinner, condensed, and well defined as plastic strain increases. This article is based on a presentation made in the symposium entitled “Fourth International Alloy Conference,” which occurred in Kos, Greece, from June 26 to July 1, 2005, and was sponsored by Engineering Conferences International (ECI) and co-sponsored by Lawrence Livermore National Laboratory and Naval Research Laboratory, United Kingdom.     

Evolution of C4 photosynthesis in response to changes in carbon and oxygen concentrations in the atmosphere through time

This work is a survey of 82 cases of keratoconus which have been followed up for 1 to 12 years. Among them only 66 were fitted with contact lenses. The contra-indications for them are: 1. a better visual acuity with spectacles than with contact lenses, 2. advanced cases (4th degree of Amsler) whose fitting is impossible, 3. unilateral keratoconus, 4. associated diseases such as trachomatous pannus, allergic kerato-conjunctivitis. Hard corneal lenses are now in use in most of the cases. Scleral lenses are much less used than they were 10 years ago, owing probably to the great improvement of the corneal lenses during this time. These hard corneal lenses have a short Ro (4 to 7 mm), an overall diameter between 8 and 11 mm, and an optic diameter of 5 mm. They are fitted under fluorescein control. The mobility must be good too. One case was fitted with soft lenses. The visual acuity is good and so is the tolerance: 80% of the patients wear their lenses 10 hours a day or more. Contact lenses do not affect the progression of keratoconus thus finally a keratoplasty must be performed in many cases. After the operation a contact lens is very often necessary, but its daily wearing time must be divided by two, to avoid corneal neo-vascularisation. Soft corneal lenses may be used in some cases of keratoconus. They are indicated when the hard lenses are no longer tolerated and before a keratoplasty. The base curves of these soft lenses are not related to the radii of the conic cornea. In most of the cases they are between 7.50 and 8.60 mm. The diameter is large: 14 or 15 mm. The lenses must not move too much: 1 mm up or down when the patient blinks. The edge of the lens must not depress the bulbar conjunctiva and there must be no air bubble under the lens. In many cases a cylindrical spectacle lens is necessary to obtain a good visual acuity. Some authors prefer to fit a hard corneal lens over the soft one: this is the "piggy back" method. Sometimes keratoconus has appeared in patients already fitted during several years to correct a myopic astigmatism. It is not clear whether these keratoconus have been produced or not be the contact lenses.     

Inflammation and the vascular changes due to thermal injury in rat hind paws

The vascular changes due to thermal injury have been determined in rat hind paws. In anaesthetized rats one hind paw has been injured by immersion in water for 30 seconds; temperature range 49-65 degrees C. Changes in blood flow, blood content and albumin content have been determined and compared with values from uninjured rats. The swelling caused by thermal injury was temperature-dependent, the higher temperatures caused the larger swellings. There were also temperature-dependent increases in blood flow to the injured paw and albumin content of the injured paw. Changes in blood content only occurred at the highest temperatures. Swelling, increased blood flow and albumin content could be detected within 1 minute of injury. The swelling and albumin content of the tissue then continued to increase gradually. The increase in blood flow was greatest 1 minute after injury and then stabilized at a flow some 4-5 times higher than normal paw flow. The method described can be used to measure vascular changes due to other inflammatory stimuli and could be applied to measure changes in other discreet areas.     

Changes in the nervous system due to occupational metallic mercury poisoning

At the Institute of Occupational Medicine and Environmental Health, during 12 years, chronic mercury intoxication was diagnosed in 34 persons. There were male workers tending technological processes in which Hg was used as a catalyst (synthesis of acetic aldehyde and obtaining chlorine). The length of professional exposure was 13-34 years (mean 20.6). The patients were removed from the contact with Hg after Hg intoxication case was confirmed. During the following 11 years, 24 of them were reexamined in the clinical department 2-4 times. The clinical picture of the poisoning consisted mainly of neurasthenic, cerebellar (30 persons), psychoorganic symptoms (20 persons) and behavioural changes (irritability, aggressive states). Headaches, sleep and recent memory disturbances, progressive behavioral changes, dizziness, were the most frequent complaints. The authors stressed the irreversibility of central nervous disorders despite cessession of the exposure to Hg. The degree of cerebellar intensity changes did not handicap examined patients. This is especially important to show the difference between the above described clinical picture of Hg intoxication and multiple sclerosis.