Physicochemical Degradation of Titania-Stabilized Soluble Phosphate Glasses for Medical Applications

Four different formulations of phosphate glasses in the system P₂O₅–CaO–Na₂O–TiO₂ were developed. Their physicochemical, morphologic, and structural evolution was analyzed during in vitro degradation in SBF (simulated body fluid) at 37°C up to 16 weeks. The results showed that the addition of TiO₂ into the glass system enhanced both the elastic modulus and the chemical durability of the glasses. Indeed, the elastic modulus increased from 66.6 to 75.95 GPa and the weight loss percentage diminished from 1.6% to 0.3% with the addition of 8 mol% TiO₂. A uniform and superficial degradation mechanism could be observed throughout the dissolution time by means of environmental scanning electron microscopy (ESEM), inductively coupled plasma mass spectroscopy (ICP-MS), and Raman spectroscopy. The degradation process undergone by these glasses allows them to maintain their mechanical properties during the degradation process. Therefore, these materials offer an interesting choice for slowly resorbable materials in biomedical applications.     

Elderly, poor, solitary and marginal patients: geriatric vulnerability in emergency services

Although tetanus is a preventable disease, several cases are reported to the Centers for Disease Control and Prevention each year. Many conditions treated by podiatric physicians carry the risk of infection by Clostridium tetani, and it is advisable for podiatrists to update a patient's tetanus immunization status if the patient presents with a tetanus-prone wound.     

Transurethral prostatic thermotherapy with microwaves (prostatron system) in bladder obstruction secondary to benign prostatic hypertrophy

Since April, 1992, 178 patients with symptomatic benign prostatic hyperplasia were treated by TUMT (363 treatments). Before entering the study, all patients had a Madsen symptom score of > 8, peak flow rate of < 15 ml/s, or average flow rate of < 10 ml/s, and post voiding residual urine of < 300 ml/s. The prostatic length was classified into group I < 50 mm (101 patients) and group II < 50 mm (77 patients). TUMT with the Prostatron device (Technomed) was performed in one, two or three session(s) of one or two hour(s) with analgosedation and on an outpatient basis. After treatment all patients were catheterized for 1-3 weeks; the morbidity rate was very low. Three and six months after treatment, the Madsen symptom score, peak flow rate, average flow rate and postvoiding residual urine improved to a high statistical significance in both groups. TUMT for benign prostatic outflow obstruction proved to be an effective treatment throughout the study period, with minimum morbidity. It must be emphasized that the degree of prostatic enlargement or the severity of the symptoms does not indicate clinical success or failure. However, the degree of bladder outflow obstruction and the quality of treatment achieved are very important: a) In patients with severe obstruction, TURP or open surgery continues to be the treatment that affords rapid relief of their symptoms. b) The clinical response to TUMT is dose-dependent; i.e., higher thermal dose, longer session (2 h) and the use of different catheters enhance the therapeutic efficacy.     

Effect of 3 organophosphates on the reproduction of Culex quinquefasciatus Say 1823

A 63-year-old woman was in hospital for persistent backache. Four months prior to admission she had been pointed out as having hypertension for the first time. On admission, she had anemia (hemoglobin 7.0 g/dl) with reticulocytosis, and a blood smear showed fragmented erythrocytes. A bone marrow aspirate disclosed erythroid hyperplasia and invasion of cancer cells. The chest roentgenogram showed a coin-lesion of the right lung and left pleural effusion. A diagnosis of microangiopathic hemolytic anemia (MAHA) associated with carcinomatosis was made, but the primary site of the cancer was unknown. Respiratory failure developed and the patient died a month later. Surprisingly, the autopsy revealed a malignant pheochromocytoma arising from the right adrenal gland with massive metastases to the lungs, liver, lymph nodes and systemic bones, and also disseminated intravascular coagulation (DIC). The DIC would probably account for the MAHA in this case. To our knowledge, this is the first reported case of malignant pheochromocytoma accompanied by MAHA.     

Controlled-rate versus uncontrolled-rate cryopreservation of peripheral blood progenitor cells: a prospective multicenter study. Group for Cryobiology and Biology of Bone Marrow Transplantation (CBTMO), Spain

BACKGROUND AND OBJECTIVE: Cryopreservation of hemopoietic progenitors for transplantation has been traditionally performed by the use of a controlled-rate freezer. Several groups have reported successful cryopreservation of progenitor cells at -80 degrees C without a controlled-rate freezer. In an attempt to elucidate whether both methods are equally efficient, we compared controlled-rate versus uncontrolled cryopreservation of peripheral blood progenitor cells (PBPC) in a prospective, multicenter study. DESIGN AND METHODS: Apheresis products from patients undergoing PBPC mobilization were split into two aliquots, and cryopreserved simultaneously by both methods, in autologous plasma plus 10% dimethylsulfoxide. Controlled-rate samples were placed into a programmable freezer with a cooling rate of 1-2 degrees C/min. Uncontrolled-rate samples were directly introduced into a -80 degrees C mechanical freezer. After thawing, cell counts, assays for viability, clonogenic cultures and CD34+ cell enumeration were performed. RESULTS: A total of 105 cases were included. No significant differences were found in viability (mean 88.8 +/- 13% in the controlled-rate group vs. 89.7 +/- 12% in the uncontrolled-rate group), nucleated cell loss (23.5 +/- 23% vs. 23 +/- 22%), mononuclear cell loss (19 +/- 23% vs. 19.1 +/- 22%), and loss of CD34+ cells (34.3 +/- 33% vs. 28.6 +/- 34%). On the other hand, recovery of granulomonocytic colony-forming units (CFU-GM), was significantly better with the controlled-rate technique, than with the non-controlled-rate method (104.3 +/- 95 vs. 86.5 +/- 80, respectively; p = 0.048). INTERPRETATION AND CONCLUSIONS: Our results indicate that both techniques are suitable for cryopreservation of PBPC, although a better recovery of committed progenitors is achieved by the controlled-rate method. Therefore, the use of controlled-rate freezer should probably be recommended.     

Solution structure of oxidized cytochrome c6 from the green alga Monoraphidium braunii

Cytochrome c6 from Monoraphidium braunii, an 89-amino acid electron transfer protein, has been investigated by NMR in solution, in its oxidized form, at pH 7 and 300 K. By using a combination of COSY, TOCSY, and NOESY experiments, 84% of the proton resonances have been assigned. A total of 1668 experimental NOE constraints, 1109 of which were meaningful, together with 288 pseudocontact shifts, have been used to determine the structure in solution. This is represented as a family of 40 structures which have been energy minimized. The rmsd values with respect to the mean structure are 0.57 +/- 0.08 and 0.94 +/- 0.09 A for the backbone and heavy atoms, respectively. The structure has been found to be very similar to that of the reduced form, except for a rearrangement in propionate 7, a feature which has been observed in all c-type cytochromes investigated so far. Such a feature could be relevant for the efficiency of the electron transfer pathway with either the oxidizing or the reducing partners. Other differences in the oxidation states have been noted in the region proposed to be involved in the interaction with the physiological partners.     

Respiration of Tribolium castaneum (Herbst) at reduced oxygen concentrations

Adults, eggs, young and old larvae and pupae of Tribolium castaneum (Herbst) were exposed to atmospheres containing 1%, 2%, 3%, 5%, 10%, and 15% oxygen in nitrogen at 30°C and 70% r.h. Respiration rates were determined with a gas chromatograph. The oxygen intake and carbon dioxide output by insects were expressed in μl/insect/h or μl/mg/h.

Adults exposed to 21% oxygen required an initial acclimatization period of at least 5 h, after which the respiration rate remained stable. Based on this finding, all the respiration measurements were carried out after an initial adaptation of insects to the respirometer conditions for 24 h.

Respiration of eggs, young and old larvae, pupae, and adults at 30°C in normal atmospheric air was at rates of 0.0121, 9.25, 8.45, 1.45, and 4.67 μl CO₂/insect/h, respectively. Respiration rates of the same stages in terms of insect weight were 0.32, 29.08, 3.33, 0.59 and 2.37 μl CO₂/mg insect/h, respectively. At reduced oxygen levels respiration rates of eggs, larvae and pupae were proportional to the oxygen levels. Adult respiration was higher for 3% and 5% oxygen than for normal atmospheric air with rates of 4.77 and 4.98 μl CO₂/insect/h, respectively. In adults, RQ values for the same oxygen levels were also higher than for normal atmospheric oxygen and were 1.07 and 1.18, respectively.     

Philadelphia positive acute lymphoblastic leukemia 16 years after the apparent cure of acute lymphoblastic leukemia. New leukemia or late relapse?

A Philadelphia-positive ALL in an adult occurring 21 years after the initial diagnosis is reported here. This case raises the question as to whether or not this event is a relapse or a new leukemia. A possible role of interferon-alpha previously administered to the patient for a chronic viral hepatitis is discussed too.     

Influence of collagen and laminin gels concentration on nerve regeneration after resection and tube repair

In order to assess the usefulness of collagen and laminin gels prefilling nerve chambers to enhance nerve regeneration, we compared reinnervation of target organs after sciatic nerve resection leaving gaps of 4 or 6 mm followed by repair with silicone tubes in different groups of mice. Tubes were prefilled with saline solution, collagen gels, or laminin-containing gels at different concentrations. Functional reinnervation was assessed by noninvasive methods to quantitate recovery of sweating, nociceptive, sensory, and motor functions in the hindpaw repeatedly during 4-5 months postoperation. The increase in gap length between nerve stumps delayed the beginning and reduced the degree of functional recovery achieved. Reinnervation started earlier and achieved slightly higher levels with collagen gel diluted at 1.28 mg/ml than with more concentrated (1.92 and 2.56 mg/ml) collagen gels and with saline-prefilled tubes bridging a 4-mm gap. Recovery was also better with diluted (4 mg/ml) than with concentrated (12 mg/ml) laminin-containing gel, although lower than with collagen gels and saline. By prefilling silicone tubes bridging a 6-mm gap, a length considered limiting for regeneration in the mouse sciatic nerve, with diluted collagen or laminin gels, both matrices allowed for higher levels of recovery and for successful regeneration in a higher proportion of mice than saline solution. The laminin gel performed slightly better than the collagen gel.