Rochalimaea henselae sp. nov., a cause of septicemia, bacillary angiomatosis, and parenchymal bacillary peliosis.

Nine strains of Rochalimaea spp. that were isolated from patients over a period of 4.5 years were characterized for their enzyme activities, cellular fatty acid compositions, and DNA interrelatedness among Rochalimaea spp., Bartonella bacilliformis, and Afipia felis (cat scratch disease bacillus). All except one isolate, which was Rochalimaea quintana, were determined to belong to a newly proposed species, Rochalimaea henselae sp. nov. After recovery from clinical material, colonies required 5 to 15 days of incubation to become apparent. Cells were small, gram-negative, curved bacilli and displayed twitching motility. Enzyme specificities for amino acid and carbohydrate substrates showed that R. henselae could be distinguished from Rochalimaea vinsonii by L-arginyl-L-arginine and L-lysyl-L-alanine peptidases, but not all strains could be distinguished from R. quintana on the basis of peptidases or carbohydrate utilization. R. henselae also closely resembled R. quintana in cellular fatty acid composition, with both consisting mainly of C18:1, C18:0, and C16:0 fatty acids. However, the strains of R. henselae all contained C18:0 in amounts averaging greater than or equal to 22%, in contrast to R. quintana, which contained this cellular fatty acid in amounts averaging 16 and 18%. DNA hybridization confirmed the identification of one clinical isolate as R. quintana and showed a close interrelatedness (92 to 100%) among the other strains. Under optimal conditions for DNA reassociation, R. henselae showed approximately 70% relatedness to R. quintana and approximately 60% relatedness to R. vinsonii. Relatedness with DNA from B. baciliformis was 43%. R. henselae was unrelated to A. felis. R. henselae is the proposed species of a newly recognized member of the family Rickettsiaceae, which is a pathogen that may be encountered in immunocompromised or immunocompetent patients. Prolonged fever with bacteremia or vascular proliferative lesions are clinical manifestations of the agent.     

Molecular identification and localization of Trp homologues,putative calcium channels,in pregnant human uterus

The mechanisms underlying the switch from uterine quiescence to contractile activity in labour are not clearly understood. Increasing evidence suggests that pathways of myometrial calcium homeostasis, including store-operated calcium entry (SOCE), may play an important role. The molecular basis of the membrane-associated calcium channels contributing to SOCE in pregnant human myometrium is not known, but they are likely to be hetero- or homo-oligomeric assemblies of transient receptor potential channel (TrpC) proteins, encoded by the mammalian homologues of Drosophila Trp genes. This study has therefore determined Trp gene expression and also TrpC protein expression and localization in term pregnant human myometrial tissue and primary cultured human myometrial smooth muscle (HMSM) cells. RT-PCR amplified fragments of Trp1, Trp3, Trp4, Trp6 and Trp7. PCR products were 100% homologous to published human sequences. Western blot analysis detected TrpC1, TrpC3, TrpC4 and TrpC6 proteins, which were of expected size. Immunolocalization revealed TrpC1, TrpC3, TrpC4 and TrpC6 protein expression in myometrial tissue and HMSM cells. TrpC protein immunostaining in HMSM cells was distributed in a distinct reticular fashion. TrpC proteins may be candidate proteins forming SOCE channels in term pregnant human myometrium.     

Pulmonary artery trunk sarcoma: a clinicopathologic, ultrastructural, and immunohistochemical study of four cases

Pulmonary artery sarcomas are rare tumors that arise in the region of the bulbus cordis, the embryologic structure that gives rise to the pulmonary trunk. Nearly 100 cases have been reported in the literature, yet considerable debate exists regarding the histogenesis and biologic properties of these neoplasms. We report four additional cases in which ultrastructural and immunohistochemical studies demonstrated that these tumors contain cellular constituents with features of myofibroblastic, cartilaginous, and osteogenic differentiation. Polyphenotypic expression of several mesenchymal lineages suggests that the progenitor cell has pluripotential properties. Our findings and a review of the literature appear to confirm that pulmonary artery sarcomas are histopathologically heterogeneous, possibly reflecting the indeterminate character of the mesenchymal cell(s) of origin. The poor prognosis is attributable to the critical anatomic location of the neoplasm rather than its metastatic potential, which is low.     

Slow excitatory amino acid receptor-mediated synaptic transmission in turtle cerebellar Purkinje cells

1. The excitatory synaptic responses of turtle Purkinje cells to climbing and parallel fiber (CF and PF) stimulation have been studied by the use of intrasomatic and intradendritic recordings in intact cerebellum and brain stem-cerebellum preparations in vitro. 2. Activation of CF inputs from the cerebellar peduncle or the region of the inferior olive evoked complex spikes followed by slow excitatory postsynaptic potentials (EPSPs), both of which were evoked in an all-or-none fashion. 3. Single stimuli applied to the cerebellar molecular layer activated fast PF-mediated EPSPs; brief trains of PF stimuli (2-5 stimuli, 50-100 Hz) evoked volleys of fast EPSPs followed by a slow, long-lasting EPSP. The amplitude of the fast and slow PF-mediated EPSPs were both graded with stimulus intensity. 4. Slow EPSPs evoked both by CF and PF stimulation were associated with an increase in membrane conductance and were increased in amplitude by hyperpolarization. 5. The CF-evoked slow EPSP was profoundly attenuated by repetitive activation at interstimulus intervals of less than 15-20 s, whereas the PF-evoked slow EPSP was not reduced by repetitive activation. 6. The PF-evoked slow EPSP readily triggered dendritic pacemaker discharges when activated at or near resting membrane potential. The activation of this potential by phasic PF volleys may, therefore, provide an appropriate synaptic drive to cerebellar Purkinje cells to entrain the intrinsic pacemaker properties of these cells to cycles of motor activity. 7. Both slow synaptic potentials were blocked by the excitatory amino acid antagonists kynurenate and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), but not by DL-2-amino-5-phosphonovalerate (DL-AP5) or L-serine-O-phosphate (L-SOP). The PF-evoked slow EPSP was selectively antagonized by L-2-amino-4-phosphonobutyrate (L-AP4; 20-100 microM). 8. It is suggested that the CF- and PF-evoked slow EPSPs observed in this study represent a novel class of excitatory amino acid receptor-mediated slow synaptic potentials activated by Purkinje cell afferents, which may play a role in synaptic integration and motor pattern generation in the cerebellum.     

Multifactorial audit of invasive cervical cancer: key lessons for the National Screening Programme.

AIMS--To audit factors associated with the development of invasive cervical cancer. METHODS--Twenty cases of invasive cervical cancer in one health district for 1991-93 were audited by multifactorial analysis. RESULTS--The average age was 53 years with 20% (4/20) aged over 65 years. Of the patients, 45% (9/20) were identified by a cervical smear, with 40% (8/20) from the National Screening Programme (NSP) and 5% (1/20) opportunistically; 30% (6/20) had not received a smear, 10% (2/20) being aged under 65 and 20% 65 or over. Those with no smear had all been hospital patients during the previous five years. No response to a smear invitation occurred in 5%. In 20%, there had been a true negative smear two to five years previously. Inappropriate laboratory diagnosis or inappropriate clinical management occurred in 30% and 15% (3/20), respectively. In 20%, two or more factors were present in the same patient. CONCLUSIONS--Why cervical cancer occurs after a true negative smear requires research and women aged over 65 with no smear must be targeted. Failsafe systems should incorporate inadequate smears and smear adequacy should be given priority in quality assurance (QA) and training. False negative reports must be minimised but accepted as an inherent part of the NSP and not an automatic indicator of poor laboratory performance. Comprehensive national QA standards are required, to which providers must conform. Postcoital bleeding is an absolute indication for a smear and, when appropriate, opportunistic smears offered at all hospital attendance. Cervical cancer audit must be guaranteed access to all clinical and laboratory information and be seen as a means to improve the effectiveness and quality of the NSP.     

Three novel PROC gene lesions causing protein C deficiency

Hallam PJ, Mannucci P, Tripodi A, Bevan D, Laursen B, Tengborn L, Wacey A, Cooper DN. Three novel PROC gene lesions causing protein C deficiency. Clin Genet 1998: 54: 231–233. 0 Munksgaard, 1998
Missense mutations. three of them novel (Am210→Val, Asn248→ Ile, Ah355→Val), were found in the protein c ( PROC ) genes of 7 patients with inherited protein C deficiency associated with venous thrombosis. Comparison with the phenotypic effects of mutations in the analogous residues of factor IX causing hdernophilia B and the use of molecular modelling has provided explanations as to how these lesions might alter either the structure, function or secretion of the protein C molecules encoded.     

Detection of penicillin tolerance in streptococci.

"Tolerance" to penicillin in streptococci was investigated by two different techniques. Of 70 strains examined, 35 appeared tolerant in conventional titrations and 31 appeared tolerant when tested by a recently-described disc method. There was 88% agreement between the two methods, but the disc test failed to detect tolerance shown by titrations in six strains of streptococci, including three beta-haemolytic strains belonging to Lancefield's group D. A significant relationship was observed between tolerance and Eagle's optimum dosage effect: 71% of tolerant strains examined displayed the Eagle effect, whereas only 17% of non-tolerant strains exhibited the effect.