In vivo UHMWPE biodegradation of retrieved prosthesis

Sixty-two ultra high molecular weight polyethylene prosthetic components (PEs) (31 tibial plateaux and 31 cups), sterilised by gamma rays or ethylene oxide (EtO), were retrieved after 1-12 years depending on different medical reasons and were studied by FTIR spectroscopy with derivatisation of oxidised species. Esters, acids and hydroperoxides were found under the surface of the EtO sterilised PEs up to 2 mm depth. The behaviour of gamma ray sterilised PEs is more complex due to the oxidation following the sterilisation process. Ester and acid formation might arise from the diffusion of components of synovial liquid or from the oxidation process, whereas hydroperoxide formation is thought to be due to the oxidation. Abrasion and delamination process is discussed considering the topological distribution of degradation products.     

Nonoperative treatment of major blunt renal lacerations with urinary extravasation

PURPOSE: We determined whether nonoperative treatment of major renal lacerations with urinary extravasation adversely affects patient outcome. MATERIALS AND METHODS: We reviewed all nonoperatively treated patients who presented between 1983 and 1994 with blunt renal trauma with major lacerations on initial staging computerized tomography. Patients with major lacerations associated with (31) and without (15) extravasation were compared for complications, blood transfusions and length of hospital stay. RESULTS: Urinary extravasation spontaneously resolved in 27 of 31 patients (87.1%), while 4 (12.9%) required a ureteral stent for persistent extravasation. No complications occurred in patients without extravasation. Mean hospitalization was 8.3 and 7.7 days for patients with isolated renal injuries with and without extravasation, respectively. Blood transfusions were required in 4 patients with and none without extravasation. CONCLUSIONS: Nonoperative treatment of major renal lacerations with urinary extravasation is safe and effective. Although delayed intervention may be required, complications can often be treated with endourological or percutaneous methods.     

The State Children''s Health Insurance Program (CHIP)

To predict the prognosis of tuberous sclerosis with West syndrome, we studied the relation between the cortical tubers and the neurological evolution. We reviewed the clinical data on the seizure evolution and developmental status of 7 patients (3 males and 4 females) and estimated the number, size and location of cortical tubers on 5 mm-thick T2-weighted MR images. The cortical tubers were grouped into categories: small (10 mm or less in maximum diameter), medium (10 to 25 mm) and large (25 mm or more). The first MRI study was performed at ages form 3 months to 18 years, and the follow-up study was performed on 6 out of the 7 patients. We also estimated the interval change of cortical tubers. The average number of cortical tubers was 12.1 per patient, being larger than the values previously reported for the patients of tuberous sclerosis without West syndrome. However, the numbers varied widely from 1 to 29. Two patients with good outcome had more than 10 tubers, whereas two patients with poor outcome had less than 5 tubers. All the patients with good outcome were female. Follow-up MRI in one patient revealed a marked increase in the number of cortical tubers, from 15 (at the age of 5 months) to 23 (at 4 years 2 months), which probably resulted from physiological hypomyelination during infancy. Some tubers corresponded to a electroencephalographic focus, whereas others did not. There was no difference in the topography of cortical tubers between the patients with good prognosis and those with poor prognosis. Thus, it was hard to make the prognosticate a case of tuberous sclerosis based solely on the number and topography of cortical tubers on MRI.     

Variations in plasma volume affect total and low-density lipoprotein cholesterol concentrations during the menstrual cycle

Serum lipids are known to vary during the menstrual cycle. To determine if changes in plasma volume contribute to this effect, we determined serum lipids, lipoproteins, and estimated changes in plasma volume in 18 premenopausal women at the start of and at 5-day intervals after menstruation. Eleven men served as a comparison group. Changes in plasma volume were estimated from changes in hemoglobin and hematocrit. Total and low-density lipoprotein (LDL) cholesterol (mean +/- SD) increased 15 +/- 14 mg/dL (9% +/- 10%) and 11 +/- 13 (11% +/- 14%) within 10 days after the start of menstruation (P < .05) and then decreased toward baseline during the rest of the cycle. High-density lipoprotein (HDL) cholesterol increased 3 mg/dL, or 5%, (P < .05) on days 10 and 15 after menstruation. Plasma volume decreased 4% +/- 9% (P < .06) 10 days after the start of menstruation, and this maximum decrease in plasma volume coincided with peak increases in total, LDL, and HDL cholesterol. Except for an 8-mg/dL increase in LDL cholesterol at day 5, lipid changes were no longer significant after adjusting for changes in plasma volume. We conclude that alterations in plasma volume account for approximately half of the increase in total and LDL cholesterol during the menstrual cycle.     

International Prognostic Index for aggressive non-Hodgkin's lymphoma is valid for all malignancy grades

An International Prognostic Index (IPI) for patients with aggressive non-Hodgkin's lymphoma (NHL) has recently been published. The IPI is based on pretreatment clinical characteristics and developed on clinical trial patients, classified as intermediate grade according to the Working Formulation (WF). We applied this IPI in a population-based registry of NHL patients. This registry does not have the restrictions that usually hold for patients in clinical trials, eg, with respect to age and performance status. Moreover, it covers all the three WF classes (low, intermediate, and high). The IPI turned out to be of prognostic value for response rate and survival in our unselected cohort of 744 patients, as well. In each of the three WF classes separately, the four IPI classes showed going from low to high substantially decreasing response rates and survival percentages. For our cohort of WF intermediate grade patients 5-year survival levels were lower in all four IPI classes (59%, 34%, 14%, and 10%, respectively), probably reflecting the selection of clinical trial patients in the original study (73%, 51%, 43%, and 26%).     

Comparative study of methods of drying mycelial waste

Two types of apparatus recommended for drying paste-like products, i.e. a continuous-belt film drier and a spouting-bed drier were tested to choose a process for drying mycelial waste. The laboratory studies with the use of the continuous-belt film drier confirmed that a dry moulded product with the moisture content of less than 5 to 6 per cent could be obtained in such an apparatus. In the laboratory and pilot plant studies with the use of the spouting-bed drier equipped with a specially constructed granulator the technological conditions of the drying were defined. The conditions provided stable hydrodynamic drying and obtaining of a dry product with the moisture content of 5 to 6 per cent. Preliminary dried and ground mycelial waste of the tetracycline and rifampicin manufacture is useful as a dry additive in the preparation of the paste with the required moisture content.     

N-terminal myristoylation is required for membrane localization of cGMP-dependent protein kinase type II

The apical membrane of intestinal epithelial cells harbors a unique isozyme of cGMP-dependent protein kinase (cGK type II) which acts as a key regulator of ion transport systems, including the cystic fibrosis transmembrane conductance regulator (CFTR)-chloride channel. To explore the mechanism of cGK II membrane-anchoring, recombinant cGK II was expressed stably in HEK 293 cells or transiently in COS-1 cells. In both cell lines, cGK II was found predominantly in the particulate fraction. Immunoprecipitation of solubilized cGK II did not reveal any other tightly associated proteins, suggesting a membrane binding motif within cGK II itself. The primary structure of cGK II is devoid of hydrophobic transmembrane domains; cGK II does, however, contain a penultimate glycine, a potential acceptor for a myristoyl moiety. Metabolic labeling showed that cGK II was indeed able to incorporate [3H]myristate. Moreover, incubation of cGK II-expressing 293 cells with the myristoylation inhibitor 2-hydroxymyristic acid (1 mM) significantly increased the proportion of cGK II in the cytosol from 10 +/- 5 to 35 +/- 4%. Furthermore, a nonmyristoylated cGK II Gly2 --> Ala mutant was localized predominantly in the cytosol after transient expression in COS-1 cells. The absence of the myristoyl group did not affect the specific enzyme activity or the Ka for cGMP and only slightly enhanced the thermal stability of cGK II. These results indicate that N-terminal myristoylation fulfills a crucial role in directing cGK II to the membrane.