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The exposed northern limb of the Bushveld Complex forms the eastern part of a much larger basin, -160 x -125 km in size based on geophysical data. Within this basin, the recently discovered ultramafic-mafic succession that extends 24 km northeast from the Hout River shear zone has been shown to have a Bushveld intrusion age of 2.06 Ga. The succession is typically 1 km thick, dips west at 34° to 38°, and comprises a basal Ultramafic sequence, a troctolite-gabbronorite-anorthosite sequence, and an Upper zone. Overlying Waterberg red beds were deposited between -2.05 and -1.93 Ma. The basal Ultramafic sequence comprises a lower orthopyroxenite <60 m thick overlying Archean granite gneisses with an intervening agmatite, which is interpreted to be remobilized footwall gneiss interfingered with pyroxenite. The upper portion of the Ultramafic sequence is composed of serpentinized harzburgite. The troctolite-gabbronorite-anorthosite sequence is <850 m thick and is dominated by gabbronorites with minor anorthosites at the top and thick troctolite layers <50 m thick, which are locally pegmatoidal, toward the base. The boundary with the Upper zone is defined by increased magnetic susceptibility due to increased cumulus magnetite. The Upper zone of ferrogabbro and magnetite gabbronorite varies between 0 and 500 m in thickness. Disseminated magnetite is ubiquitous but magnetitite layers that are characteristic of the Upper zone elsewhere in the Bushveld Complex are lacking, except in one core from the extreme south of the project. There are two PGE-Cu-Ni-Au mineralized intervals, a lower F zone and an upper T zone that vary from 3 to 60 m in thickness. The T zone is restricted to the southern portion of the project, whereas the F zone extends 17 km along strike. In both there is a correlation between visible chalcopyrite and pentlandite abundance and grade of PGE. The F zone of the Ultramafic sequence hosts disseminated sulfides with accessory chromite. Platinum group minerals (PGM), based on more than 1,000 grains recovered, are dominated by sperrylite with lesser Pt-Pd bismuthotellurides, Au-Ag alloys, Pd arsenides, and Pt-Rli sulfoarsenide with a grade of <7 g/t Pt + Pd + Au. The precious metal budget comprises 64% Pd, 30% Pt, 1% Rh, and 5% Au with 0.16% Ni and 0.07% Cu. Mineralization occurs over an interval o f -10 m although in the central portion of the northeasterly oriented body, the "Super F zone" thickens to 60 m, with grades of 3 g/t over this interval. The T zone occurs in a lithologically variable sequence close to the boundary between the troctolite-gabbronorite-anorthosite sequence and the Upper zone. In the south, the T zone is ~30 m thick but increases northward to >50 m thick. An upper T1 and lower T2 are separated by a barren middling that is sometimes absent. Grade in both T1 and T2 is indicated as 3.88 g/t Pt + Pd + Rh + Au, although locally with up to 14 g/t. PGM are less varied than in the F zone and are dominated by Pt-Pd bismuthotellurides. Both T1 and T2 zones have a consistent and unusually gold-enriched metal ratio of ~49% Pd, ~29% Pt, 1% Rh, and 21% Au with 0.08% Ni and 0.16% Cu. Neither the T nor F mineralized zones has direct correlatives in other limbs of the Bushveld Complex. Although there are comparisons with the Bushveld succession elsewhere, significant differences in thickness and type of lithologies, geochemistry, and mineralization of this arcuate intrusion of the Waterberg segment, compared to the eastern, western, and northern limbs of the Bushveld Complex, suggest that the Waterberg ultramafic-mafic body may represent a structurally controlled separate compartment north of the Hout River shear zone. [ABSTRACT FROM AUTHOR]

Unlabelled: OBJECTIVE--To evaluate the efficacy and safety of ceftriaxone sodium in the treatment of streptococcal endocarditis. DESIGN--An open, multicenter, noncomparative study with a follow-up of patients for 4 months to 5 years. SETTING--Internal medicine wards and outpatient clinics of hospitals of various sizes in three European countries. PATIENTS--Fifty-nine patients with defined criteria for streptococcal endocarditis. INTERVENTION--Ceftriaxone sodium administered at a once-daily dose of 2 g for 4 weeks. MAIN OUTCOME MEASURES--Clinical outcome and microbiological cure rate. RESULTS--Among the 59 patients, 55 completed the treatment and were followed up for 4 months to 5 years. No patients showed evidence of relapse. Treatment was completely uneventful in 42 patients (71%). A cardiac valve was replaced in four patients (7%) receiving antimicrobial therapy and in six patients (10%) who had completed antimicrobial therapy. One of the 10 valves taken for culture at surgery was positive, but only for microorganisms that were different from the microorganism isolated before the treatment. The treatment had to be interrupted in four patients because of drug allergy. Other side effects were mild except for two cases of reversible neutropenia. The treatment was easy to administer: 27 patients (46%) had no permanent intravenous catheter at any time, seven patients (12%) had such a catheter for less than 4 days. Twenty-three patients (39%) were discharged from the hospital less than 2 weeks after admission.Conclusions: --Ceftriaxone sodium administered at a once-daily dose of 2 g appears to be an effective and safe treatment of streptococcal endocarditis. In hospitals, this agent may be more convenient to administer than penicillin G with or without aminoglycosides. Some patients may even be treated as outpatients. [ABSTRACT FROM AUTHOR]

A comparative study of the levels of netilmicin in bronchial secretions after intermittent and during continuous intravenous injections was performed. During the first 2 h, the areas under the drug concentration curves in the bolus injection experiment were greater in serum and in bronchial secretions (206 and 150% respectively) than those associated with the continuous infusion (P<0.001); however, during the 8 h experimental period, the areas under the curves were similar in serum and bronchial secretions with the two modes of administration. The percentages of penetration of netilmicin from the blood to the bronchial lumen were also similar with the two modes of administration (19%). After intramuscular administration of amikacin (7.5 and 12.5 mg/kg twice daily), the peak bronchial secretion levels of the drug were 4.4 and 10.1 mg/l respectively and the trough levels about 1 mg/l. During continuous iv injection of amikacin (7–12 mg/kg/8 h), the drug level in the bronchial secretions was only 2.0 mg/l and the percentage of penetration was 14.9% adequate anti-Pseudomonas activity in bronchial secretions was rarely achieved. It is therefore suggested that intermittent injections of aminoglycosides can result in at least transitory higher bronchial secretion levels than continuous injection: the intermittent schedule of antibiotic administration could therefore be recommended in the treatment of bronchopulmonary infections since it has been suggested that the concentration of antibiotic in bronchial secretions could be important in the outcome of these infections. [ABSTRACT FROM PUBLISHER]

Ciprofloxacin concentrations in serum and in bronchial secretions were studied after single and multiple intravenous administrations for two days in ten patients. The dose given was either 0.75 or 1.5 mg/kg With the lower dose, the peak concentrations in the bronchial secretions were (mean ± S.D.) 0.40±0.29 mg/l after the first injection and 0.35±0.25 mg/l after the fourth injection. With the higher dose, the corresponding mean peak bronchial concentrations were 0.84±0.58 and 1.16±0.86 mg/l respectively. The haif-lifes of the drug in bronchial secretions ranged from 2.13 to 3.72 h. The penetration of ciprofloxacin into bronchial secretions was excellent as demonstrated by the high ratios of the areas under the concentration curves obtained in the serum and in bronchial secretions which ranged from 0.79 to 1.11. [ABSTRACT FROM PUBLISHER]

The bio-inactivation of netilmicin and amikacin by binding with intact and disrupted human normal leucocytes was compared. Even after prolonged incubation of the aminoglycosides with intact cells, no binding could be demonstrated. On the other hand, partial binding of netilmicin and amikacin by disrupted leucocytes occurred: a linear relationship between the logarithm of the initial number of cells and the degree of binding of the drug was observed. The decrease in biological activity occurred rapidly in the presence of disrupted cells and remained unchanged during the next 18 h. [ABSTRACT FROM AUTHOR]

In-vitro study of the combination of oxacillin with rifampicin has shown that a complex interaction occurs between the two drugs: a high oxacillin/rifampicin ratio was associated with antagonism, a low ratio was more likely to result in synergy - the combination acquired a higher rate of killing. Oxacillin significantly prevented or delayed the regrowth of rifampicin-resistant mutants, and antagonism for high oxacillin/rifampicin ratios only affected rifampicin-susceptible strains.The two clinical studies that we have performed suggested that the addition of rifampicin to standard treatment improved the clinical outcome of the patients with staphylococcal infections, and this was particularly true for the most severe infections. Failures were not associated with the emergence of rifampicin-resistant strains; the combination was not associated with more superinfections nor with more toxicity or intolerance.Serum bactericidal activities reflected a similar complex interaction to that observed in vitro by time-kill curves or checkerboard techniques. [ABSTRACT FROM PUBLISHER]

In a case of brain death, a Clostridium sordellii and Escherichia coli septicaemia--of probable gastrointestinal origin--developed and was associated with a diffuse clostridial myositis. Factors responsible for the initiation and development of this unusual clostridial infection are discussed. [ABSTRACT FROM PUBLISHER]