Production of materials with alumina and ashes from incineration of chromium tanned leather shavings: environmental and technical aspects

The leather tannery industry produces a significant amount of solid and hazardous wastes. Chromium-containing wastes like tanned shavings used to be incinerated in order to recover energy. The incineration process generates ashes that must be disposed of. This paper is a report on the results of the evaluation of technological properties and environmental compatibility of products made of alumina and ashes from incinerated chrome tanned shavings. The raw materials, tannery ashes and alumina were mixed together in different proportions. The ceramic bodies were molded using a hydraulic press and fired with a heating rate of 100 K/h until 1400 degrees C for 4 h in a muffle furnace. The ceramic specimens were characterized regarding physical, mechanical and thermal properties. Leaching tests, according to Brazilian, German and Dutch regulations, were performed on ceramic bodies containing different additions of ash. Results show that the ceramic materials produced are acceptable for refractory applications.

Severe complications following intravesical BCG instillation

In patients with urinary bladder carcinoma, the intravesical BCG instillation is widely used. We present two cases of severe pulmonary afflictions developed during this treatment. The possible mechanisms of etiology are discussed and the classification of the intravesical BCG treatment side effects is suggested.

Immunosuppressive treatment of Crohn's disease with fistulae

The rise of fistulae in Crohn's disease has been classed with the disorder complications, although it is a possible component of natural development of the so-called A type (De Dombal classification) or aggressive-perforating type (Greenstein's classification) of this idiopathic intestinal inflammation. Fistulae are accompanying colic localization of Crohn's disease in 20%, ileocolic affection in 40%, where 35% of them are perianal fistulae, and about 34% entero-enteral or entero-cutaneous ones. Other complications (urogenital tract, biliary tract) are mentioned infrequently in literature. Besides surgical approaches in the therapy, dominant post in the conservative area is taken up by an antitumor necrotizing factor, antibiotics and immunosuppressives whose position is, however, the most problematic although the literature references about the effectiveness of azathioprine, 6-mercaptopurine, cyclosporine, tacrolime and methotrexate have had nearly 25-years tradition. The authors present their own experience with applying a combination of cyclosporine, azathioprine in the treatment of perianal fistulae in a set of 21 patients from the period of 1995-2000. In their opinion, the therapy success is limited especially by early starting the treatment (11 cases of effective therapy) and choosing a resolute method that is, according to them, sequential immunosuppression. (Tab. 2, Ref. 32.)

On the generation of point groups in spaces of various dimensions

In this paper the use of Clifford algebra in the parametrization of point groups in spaces of various dimensions is shown. Higher-dimensional spaces are of great interest especially when modulated crystals or quasicrystals are studied. While the quaternion units, which are useful to parametrize rotations in 3 dimensions, can be identified with rotations, the basic Clifford units may be regarded as mirrors from which all proper and improper symmetry operations can be generated. The practical implementation of this method of parametrization is demonstrated for the group of the hypercube in the 4-dimensional space, and generalisations to spaces of dimensions higher than 4 are suggested.

Association of a fluorescent amphiphile with lipid bilayer vesicles in regions of solid-liquid-disordered phase coexistence

The effects of solid-fluid phase separations on the kinetics of association of a single-chain fluorescent amphiphile were investigated in two different systems: pure DMPC (dimyristoylphosphatidylcholine) and a 1:1 mixture of DMPC and DSPC (distearoylphosphatidylcholine). In pure DMPC vesicles, solid (s) and fluid (l(d)) phases coexist at the phase transition temperature, T(m), whereas a 1:1 mixture of DMPC and DSPC shows a stable s-l(d) phase separation over a large temperature interval. We found that in single-component bilayers, within the main phase transition, the experimental kinetics of association are clearly not single-exponential, the deviation from that function becoming maximal at the T(m). This observation can be accounted for by a rate of desorption that is slower than desorption from either fluid or solid phases, leaving the rates of insertion unchanged, but a treatment in terms of stable fluid and solid domains may not be adequate for the analysis of the association of an amphiphile with pure DMPC vesicles at the T(m). In DMPC/DSPC mixtures with solid-fluid phase coexistence, association occurs overall faster than expected based on phase composition. The observed kinetics can be described by an increase in the rate of insertion, leaving the desorption rates unchanged. The fast kinetics of insertion of the amphiphile into two-phase bilayers in two-component vesicles is attributed to a more rapid insertion into defect-rich regions, which are most likely phase boundaries between solid and fluid domains. A two-component mixture of lipids that shows a stable phase separation between l(d)-s phases over a large temperature interval thus behaves very differently from a single-component bilayer at the T(m), with respect to insertion of amphiphiles.

Commercial polymerase chain reaction test (Amplicor set) in the diagnosis of smear-negative pulmonary tuberculosis from sputum and bronchoalveolar lavage

The study presents experience with polymerase chain reaction (PCR) in the diagnosis of tuberculosis (TB) and compares the results obtained in sputum and bronchoalveolar lavage fluid (BALF). A total of 1,097 samples from 846 smear-negative patients with suspected TB was examined using PCR and culture during a period of 40 months. TB was the final diagnosis in 160 patients, based on the evidence of mycobacteria in 90 patients and on clinical criteria in the remaining 70. The PCR test had high specificity (98% and 99%, respectively) but poor sensitivity (37% and 34%, respectively) regardless of whether sputum or BALF was examined. Surprisingly, the sensitivity of culture (44% and 35% in sputum and BALF, respectively) was higher than that of PCR in this group. The contribution of BAL to establishing the diagnosis of tuberculosis was rather limited, yet substantial in some patients. The results obtained in this study were compared with the results published in the literature, and it was concluded that further clinical studies are necessary to establish an appropriate role for the polymerase chain reaction in the diagnosis of tuberculosis.

Kinetics of amphiphile association with two-phase lipid bilayer vesicles

We examined the consequences of membrane heterogeneity for the association of a simple amphiphilic molecule with phospholipid vesicles with solid-liquid and liquid-liquid phase coexistence. To address this problem we studied the association of a single-chain, fluorescent amphiphile with dimyristoylphosphatidylcholine (DMPC) vesicles containing varying amounts of cholesterol. DMPC bilayers containing 15 mol% cholesterol show a region of solid-liquid-ordered (s-l(o)) coexistence below the T(m) of pure DMPC (23.9 degrees C) and a region of liquid-disordered-liquid-ordered coexistence (l(d)-l(o)) above the T(m). We first examined equilibrium binding and kinetics of amphiphile insertion into single-phase vesicles (s, l(d), and l(o) phase). The data obtained were then used to predict the behavior of the equivalent process in a two-phase system, taking into account the fractions of phases present. Next, the predicted kinetics were compared to experimental kinetics obtained from a two-phase system. We found that association of the amphiphile with lipid vesicles is not influenced by the existence of l(d)-l(o) phase boundaries but occurs much more slowly in the s-l(o) phase coexistence region than expected on the basis of phase composition.

Dehydroepiandrosterone in the treatment of erectile dysfunction: a prospective, double-blind, randomized, placebo-controlled study

OBJECTIVES

In 1994, the Massachusetts Male Aging Study presented an inverse correlation of the serum levels of dehydroepiandrosterone (DHEA) and the incidence of erectile dysfunction (ED). We evaluated the efficacy of DHEA replacement in the treatment of ED in a prospective, double-blind, randomized, placebo-controlled study.

METHODS

The inclusion criteria included ED, normal physical and neurologic examinations, serum levels of testosterone, dihydrotestosterone, prolactin, and prostate-specific antigen (PSA) within the normal range, and a serum DHEA sulfate level below 1.5 micromol/L. Also all patients had a full erection after a pharmacologic erection test with 10O microg prostaglandin E1; pharmacocavernosography showed no visualization in corporeal venous structures. Forty patients from our impotence clinic were recruited and randomly divided into two groups of 20 patients each. Group 1 was treated with an oral dose of 50 mg DHEA and group 2 with a placebo one time a day for 6 months. The International Index of Erectile Function (IIEF), a 15-item questionnaire, was used to rate the success of this therapy.

RESULTS

Therapy response was defined as the ability to achieve or maintain an erection sufficient for satisfactory sexual performance according to the National Institutes of Health Consensus Development Panel on Impotence. DHEA treatment was associated with higher mean scores for all five domains of the IIEF. There was no impact of DHEA treatment on the mean serum levels of PSA, prolactin, testosterone, the mean prostate volume, and the mean postvoid residual urine volume.

CONCLUSIONS

Our results suggest that oral DHEA treatment may be of benefit in the treatment of ED. Although our patient data base is too small to do relevant statistical analysis, we believe that our data show a biologically obvious trend that justifies further extended studies.

Sperm analysis and serum follicle-stimulating hormone levels before and after adjuvant single-agent carboplatin therapy for clinical stage I seminoma

OBJECTIVES

During the past 25 years, radiotherapy has been considered the standard adjuvant treatment for clinical Stage I seminoma after orchiectomy. However, the late effects of this treatment have prompted a re-examination of the alternatives, including surveillance and adjuvant administration of carboplatin. To our knowledge, the present clinical study is the first to report the effects of two adjuvant courses of single-agent carboplatin on the pituitary-testicular axis and on sperm analysis.

METHODS

Twenty-two patients with clinical Stage I seminoma participated in a prospective investigation of gonadal function before and after carboplatin therapy. After orchiectomy but before chemotherapy, blood samples for determination of follicle-stimulating hormone (FSH) serum levels were obtained from all 22 patients. Seventeen patients provided a semen sample at the same time, but 5 were unable to do so. At the end of chemotherapy, all 22 patients provided repeated semen samples starting 1 year after the termination of treatment and continuing at intervals of 12 months. FSH serum levels were determined at the same time. The study period was 48 months.

RESULTS

Before chemotherapy, 2 patients (12%) had azoospermia, 9 (53%) had oligospermia, and 6 (35%) had normospermia. During the study period, sperm counts continued to increase in all patients. After 4 years, 7 patients (32%) had oligospermia and 15 (68%) normospermia. The mean prechemotherapy FSH level (15.5 IU/L) was increased in accordance with subnormal spermatogenesis, but a constant trend toward normalization was observed thereafter.

CONCLUSIONS

Our results show recovery of spermatogenesis after adjuvant single-agent carboplatin for clinical Stage I seminoma in a remarkably high percentage of patients.

Evaluating alcoholism and drug abuse knowledge in medical education: a collaborative project

A series of six modular examinations, each representing a substance abuse problem, were developed by a National Institute on Drug Abuse task force working with consultants from the National Board of Medical Examiners (NBME). Each examination contained a patient management problem and multiple-choice questions. The examinations were administered to 629 third- and fourth-year U.S. medical students, and the results indicated that students performed less well in this area than on the traditional content of the NBME examinations. Students performed better on items related to pharmacologic effects of drugs of abuse, Alcoholics Anonymous, and the treatment of delirium tremens. Students did less well on items related to metabolic and biochemical areas; emergency room treatment of drug-overdosed, comatose patients; and legal issues in substance abuse. As a result of these data, a syllabus explaining each item in the available modules was developed, score-reporting to participating schools was modified, and the modules were shortened. Implications for medical education in substance abuse are discussed.

Mental and emotional disturbance with pentazocine (Talwin) use

Pentazocine (Talwin) originally was believed to be a safe, nonaddictive analgesic, but further experience has shown that severe mental and emotional disturbance, as well as addiction, may occur. This survey documents the experience in the Texas Medical Center and elsewhere. The accumulated data show the following: (1) Depressive states are reported most frequently, while toxic psychoses, hallucinogenic reactions with panic, and paranoid states on withdrawal of the drug are less frequent. (2) Of the 197 cases of addiction reported to date, only six were related to oral use of the drug. The abstinence syndrome is mild, consisting usually of restlessness, nausea, cramps, and insomnia. (3) Convulsions have been reported on four occasions. Euphoria and psychotomimetic effects may relate to rapid release of noradrenaline and dopamine. Oral use of the drug is advised to avoid euphoriant effects and addiction, and physicians should alert patients to report unusual visual phenomena. Tranquilizers are of value in cases of severe reactions.