Culturable Rhodobacter and Shewanella species are abundant in estuarine turbidity maxima of the Columbia River.

Measurements of dissolved, ascorbate-reducible and total Mn by ICP-OES revealed significantly higher concentrations during estuarine turbidity maxima (ETM) events, compared with non-events in the Columbia River. Most probable number (MPN) counts of Mn-oxidizing or Mn-reducing heterotrophs were not statistically different from that of other heterotrophs (10³ -104 cells ml⁻¹) when grown in defined media, but counts of Mn oxidizers were significantly lower in nutrient-rich medium (13 cells ml⁻¹). MPN counts of Mn oxidizers were also significantly lower on Mn(III)-pyrophosphate and glycerol (21 cells ml⁻¹). Large numbers of Rhodobacter spp. were cultured from dilutions of 10⁻² to 10⁻5, and many of these were capable of Mn(III) oxidation. Up to c. 30% of the colonies tested LBB positive, and all 77 of the successfully sequenced LBB positive colonies (of varying morphology) yielded sequences related to Rhodobacter spp. qPCR indicated that a cluster of Rhodobacter isolates and closely related strains (95-99% identity) represented approximately 1-3% of the total Bacteria, consistent with clone library results. Copy numbers of SSU rRNA genes for either Rhodobacter spp. or Bacteria were four to eightfold greater during ETM events compared with non-events. Strains of a Shewanella sp. were retrieved from the highest dilutions (10⁻5) of Mn reducers, and were also capable of Mn oxidation. The SSU rRNA gene sequences from these strains shared a high identity score (98%) with sequences obtained in clone libraries. Our results support previous findings that ETMs are zones with high microbial activity. Results indicated that Shewanella and Rhodobacter species were present in environmentally relevant concentrations, and further demonstrated that a large proportion of culturable bacteria, including Shewanella and Rhodobacter spp., were capable of Mn cycling in vitro.

Diastematomyelia in an adult.

Surgical treatment of diastematomyelia, with removal of the spur and dural septum, is indicated in adults with progressive symptoms. The patient may improve, or at least the progression of the neurological damage may be halted. The utilization of microneurosurgical techniques was found to be of value in decreasing the danger of spinal cord or nerve injury during the procedure. The seventh case reported in the literature of diastematomyelia with onset of symptoms in adult life is presented.

Warfarin therapy initiated during pregnancy and phenotypic chondrodysplasia punctata.

An infant is described who has clinical manifestations and roentgenographic features consistent with the diagnosis of chondrodysplasia punctata. The mother of this infant received warfarin during pregnancy. Eight cases demonstrating an association between warfarin therapy during pregnancy and chondrodysplasia punctata in the child have been reported; in the present case therapy was initiated following conception (see following case report). Warfarin may be teratogenic, producing a phencopy of the heritable forms of chondrodysplasia punctata. Because of the evident association we suggest (1) warfarin is contraindicated in pregnancy and alternative anticoagulants should be used; (2) products of at-risk pregnancies should be screened for the characteristic radiologic findings; and (3) preconceptual counselling and antenatal diagnosis of the disease may be beneficial.