Abdominal wall hematoma]

We describe three case reports of hematomas in the abdominal wall muscles and discuss etiology, diagnostic findings and treatment. Abdominal wall hematomas are uncommon, and the condition is often misdiagnosed. One of our patients was laparotomised owing to suspected appendicitis, and one patient presented a tuberculous abscess that may have been an infected hematoma. Ultrasonographic examination or CT gives the correct diagnose. Conservative management is the treatment of choice unless bleeding is severe or the course is complicated by infection.     

The characterization of weathered discard coals and their behaviour during combustion

With a finite amount of economically viable coal reserves in South Africa, it is becoming increasingly important to consider coal discards as vital energy resources. The energy content of discard coal is generally low and high in ash, but can be effectively utilised in power stations. However, coals weather during storage, and weathered coals behave differently to their fresh counterparts. During this investigation, discard coals from four stockpiles varying in age from 5 to 40 years were characterised chemically and petrographically, with a specific focus on the petrographic-based abnormal condition analysis to determine the degree of secondary weathering. Drop tube furnace tests were conducted to determine the combustibility of the weathered stockpiled or dumped coals relative to typical Eskom coals, and the resultant char forms were characterised. A direct correlation with the extent of weathering and combustion performance was determined, with the more weathered coals reporting enhanced combustion reactions at lower temperatures.     

A source apportioned mercury mass balance across a coal-based petrochemical complex

Coal-fired power generation facilities are the largest single anthropogenic source of mercury to the atmosphere. Global mapping of anthropogenic emissions has previously estimated the mercury emission from stationary combustion from South Africa at being 82.6 tonnes per annum, but preliminary in-house calculations have placed this at a significantly lower amount. A petrochemical facility in South Africa, utilising a significant amount of coal in its gasification and steam generation processes, undertook a project to determine a mercury mass balance across the complex, and to apportion the Hg emissions from the facility.     

Effects of the intermediate retinoid metabolite retinal on the pattern of the dental lamina in vitro

Retinoids have important roles in pattern formation during embryonic development and might act as endogenous morphogens. They are necessary for normal odontogenesis and excess retinol alters the pattern of odontogenesis producing supernumerary buds of the dental lamina in the diastema region of the mouse mandible. Because the metabolism of retinoids in the developing mandible is unknown, the effects of retinal (an intermediate metabolite in the local conversion of retinol to retinoic acid) on the patterning of odontogenesis were examined. Retinal produces supernumerary buds and enhanced epithelial proliferation in day-9 mandibles in vitro. The endogenous levels of retinal in the mandible at the time of initiation of odontogenesis were also measured by high-performance liquid chromatography. Retinal was detected only at day 10 and not at later stages of development. Local metabolism of this intermediate retinoid may be a rate-determining step in the production of active retinoid metabolites that may control the pattern of the dentition, which is established at the time of the appearance of the dental lamina at embryonic day 12.     

BMP-2 and BMP-4, but not BMP-6, increase the number of adrenergic cells which develop in quail trunk neural crest cultures

Isolated rat liver mitochondria were incubated under various metabolic conditions to determine their membrane potential (MMP) as measured continuously by a tetraphenylphosphonium (TPP+)-selective electrode. By flow cytometry, a parallel analysis of fluorescence emissions observing single mitochondria stained with the lipophilic cation 5,5',6,6'-tetrachloro-1,1'3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1) revealed linear correlation between the median orange fluorescence (FL2) due to J-aggregate formations and MMP values measured by TPP+. No correlation was detected with the green fluorescence (FL1) emission. A significantly higher correlation appeared between the FL2/FL1 ratio and MMP values. Within the same mitochondrial population, cytofluorimetric analysis revealed the presence of various classes of organelles with different MMP, whose distribution was dependent on metabolic condition. The highest functional heterogeneity was found in deenergized mitochondria, while the highest homogeneity was observed during the first phase of the phosphorylative process. Thus, these data suggest that the cytofluorimetric use of JC-1 provides direct experimental evidence for the hypothesis of functional mitochondrial heterogeneity, at least with respect to their membrane potential.     

X-linked juvenile retinoschisis: localization between (DXS1195, DXS418) and AFM291wf5 on a single YAC

We studied 17 pedigrees with 108 affected males with X-linked juvenile retinoschisis (RS; McKusick No. 31270) and have analyzed all of the known polymorphic markers in the RS region of Xp22.1-p22.2 between DXS987 and DXS41. By haplotype analyses we found 7 individuals who showed crossovers in this interval surrounding RS. We previously reported AFM291wf5 as the centromeric boundary, and this remains unchanged in the present study. A new recombination was identified on the telomeric side at (DXS1195, DXS418). Our data support the locus order Xpter--(DXS987, DXS207, DXS1053, DXS43)--(DXS1195, DXS418)--(RS, DXS257, DXS999)--(AFM291wf5, DXS443)--DXS1052--(DXS1226, DXS274, DXS41)--Xcen; loci grouped in parentheses could not be mutually ordered by our genetic data. Physical mapping has indicated a distance of at most 900-1,000 kb between (DXS1195, DXS418) and AFM291wf5. No recombination was observed between RS and DXS257 which lies in our new interval of interest, but one critical individual was not informative with this marker. Our data now define the smallest RS inclusion interval. This interval is contained on a single YAC from which we have identified expressed sequences as candidate genes for RS.     

Repair of DNA methylphosphotriesters through a metalloactivated cysteine nucleophile

The Escherichia coli Ada protein repairs methylphosphotriesters in DNA by direct, irreversible methyl transfer to one of its own cysteines. Upon methyl transfer, Ada acquires the ability to bind specific DNA sequences and thereby to induce genes that confer resistance to methylating agents. The amino-terminal domain of Ada, which comprises the methylphosphotriester repair and sequence-specific DNA binding elements, contains a tightly bound zinc ion. Analysis of the zinc binding site by cadmium-113 nuclear magnetic resonance and site-directed mutagenesis revealed that zinc participates in the autocatalytic activation of the active site cysteine and may also function as a conformational switch.     

A comparison of the W-stapled ileal reservoir with hand-sewn reservoirs for orthotopic bladder replacement

Activated calpain I immunoreactivity (76 kDa band) was detected in membranes prepared from rat brain hippocampal slices using a polyclonal antiserum raised against an N-terminus peptide of the cleaved subunit of calpain I. While basal levels of activated calpain I were stable over incubation times, 1 nM dopamine (DA) produced an initial 32% increase (5 min) in the 76 kDa protein followed by a 53% decrease in this band at 20 min of incubation. The DA-induced changes in activated calpain I immunoreactivity were blocked by the calpain inhibitor peptide, N-acetyl-Leu-Leu-norleucinal(100 microM) or by EGTA. Basal levels of the 76 kDa band were not affected by the calpain inhibitor. These changes in activated calpain I, elicited by DA, are in accord with the DA-induced decreases in the levels of the calpain substrate, gamma PKC (Yurko-Mauro and Friedman; J Cell Biochem [Abstr] 180:80, 1994; J Neurochem 65: 1622-1630, 1995) and suggest that DA activates this Ca(++)-dependent protease in its regulation of neuronal signal transduction.