Agenesis of permanent incisors in a mediaeval maxilla and mandible: aetiological aspects

A paleopathological maxilla and mandible with tooth agenesis were analyzed, focussing on the aetiology of the condition. The jaw material, derived from an adult mediaeval male, was examined by standard anthropological analyses, including radiography. In the maxilla there was agenesis of three permanent incisors and one premolar, and in the mandible of one permanent incisor and two permanent molars. Absence or marked reduction of the incisive foramen and the nasopalatine canal was found. The pattern of tooth agenesis was similar to the pattern observed in contemporary individuals, except for the agenesis of one permanent maxillary centreal insisor. It is suggested that the pronounced lack of the premaxillary area of the nasopalatine canals and the incisive foramen. As the condition can be ascribed to deviations in the prenatal developments, this investigation shows that embryological developmental patterns, which form the basis for the pattern of tooth agenesis, should be taken into account when evaluation dry bonde patholgy.     

Biochemical characteristics of 130 recent isolates from Haemophilus influenzae meningitis.

A total of 130 Haemophilus strains, comprising virtually all isolates from Danish and Norwegian cases of Haemophilus meningitis occurring in the period from October 1975 through September 1976, were examined by biochemical and serological means. All isolates were identified as H. influenzae and, except for one noncapsulated strain, possessed a capsule of serotype b. The vast majority of strains (93%) belonged to biotype I, which, in contrast to biotypes II and III, is rarely encountered as a commensal of the upper respiratory tract. This finding is a strong incentive for studies of possible additional virulence factors associated with biotype I organisms. The results are discussed in the light of North American reports, which have suggested changes in the etiology of Haemophilus meningitis.     

Isolation ofPasteurella multocida in a patient with spontaneous peritonitis and liver cirrhosis

A case of spontaneous bacterial peritonitis caused by Pasteurella multocida in a 12 year old boy with previously undiscovered cirrhosis of the liver is reported. This case is discussed and related to eight published cases of spontaneous peritonitis caused by Pasteurella multocida in adults, seven with cirrhosis of the liver and/or alcohol abuse, and one with systemic lupus erythematosus complicated by membranoproliferative glomerulonephritis. It would appear that spontaneous bacterial peritonitis caused by Pasteurella multocida is not confined to adults with a history of alcohol abuse or cirrhosis of the liver, but can also affect children with non-alcoholic cirrhosis of the liver.     

Polymorphism in ospC gene of Borrelia burgdorferi and immunoreactivity of OspC protein: implications for taxonomy and for use of OspC protein as a diagnostic antigen.

The nucleotide sequences of the ospC gene from five Danish human Borrelia burgdorferi isolates representing all three B. burgdorferi genospecies (B. burgdorferi sensu stricto, Borrelia garinii sp. nov., and group VS461) and from the American type strain B31 were determined and compared with the published ospC sequence from the German B. burgdorferi isolate PKo (R. Fuchs, S. Jauris, F. Lottspeich, V. Preac-Mursic, B. Wilske, and E. Soutschek, Mol. Microbiol. 6:503-509, 1992). The ospC gene was present in all isolates, regardless of the presence or absence of its product, OspC. The deduced amino acid sequences of OspC from the seven isolates were aligned and revealed pairwise sequence identities ranging from 60.5 to 100%. Differences were scattered throughout the amino acid sequences. A phylogenetic tree was constructed and revealed three distinct phenotypic groups OspCI to OspCIII corresponding to the three delineated genospecies. Immunoblot analysis revealed that the seven OspC proteins tested have both common and specific epitopes. There is significant epitope diversity, since even polyclonal antisera showed serotype-restricted specificity. Therefore, a serodiagnostic assay for Lyme borreliosis utilizing OspC as a test antigen should include all three OspC phenotypes in order to obtain a species-wide sensitivity.     

The effect on total renal and tubular function and plasma renin of a moderate isotonic saline load in rats anesthetized with amytal and inactin.

The renal effects of i.v. saline loading equal to 1% body weight (b.wt.) were studied in 2 groups of rats: group I was anesthetized with Amytal (15 mg/100 g b.wt. plus supplementary doses), group II with Inactin (12.5-15.0 mg/100 g b.wt.). In group I the saline load caused an increase in urine flow (+92%), solute excretion (+67%), inulin clearance (CIN) (+24%), PAH clearance (+31%) and absolute proximal reabsorption rate (+27%). Proximal fractional reabsorption and filtration fraction (FF) remained unchanged, while plasma oncotic pressure (COP) decreased by 10%. Plasma renin fell and there was an inverse relationship between renin concentration and proximal reabsorption rate. In group II urine flow and solute excretion increased after saline (+85% and 110%, respectively); CIN and absolute proximal reabsorption rate was lower than in group I and failed to increase after saline. Proximal fractional reabsorption was also lower and decreased after saline. COP as well as renin decreased as in group I, but no relationship between renin concentration and proximal reabsorption rate could be demonstrated. The data indicate that Inactin depresses both resting proximal tubular reabsorptive capacity and the tubular response to a physiological volume expansion. The results are compatible with the hypothesis that the renin-angiotensin system is significantly involved in regulation of proximal tubular function, while they are incompatible with the idea that peritubular COP plays any major role in this adjustment.     

TNF-alpha impairs peripheral tolerance towards beta-cells,and local costimulation by B7.1 enhances the effector function of diabetogenic T cells

Maintenance of peripheral tolerance and inactivation of autoreactive T cells is based on a delicate balance between pro-inflammatory and protective cytokines that is poorly understood. We have here addressed how the local expression of the inflammatory cytokine TNF-alpha can impair peripheral tolerance and lead to autoreactivity. After transplantation of pancreata that are immunogenic due to beta-cell expression of B7.1 and TNF-alpha, into thymectomized and euthymic syngeneic mice, we found that only euthymic mice rejected the grafts. This result suggests that under normal circumstances autoreactive T cells are functionally inactivated, and initiation of an autoreactive response requires de-novo generation of T cells. By contrast, thymectomized mice expressing TNF-alpha on the endogenous islets rejected the grafts, showing that expression of TNF-alpha prevents functional silencing of the autoreactive T cells. Thus, this study provides a mechanism by which TNF-alpha and possibly chronic inflammatory responses may promote autoimmune diseases. Furthermore, we have investigated whether B7.1 can enhance T cell responses of already activated T cells leading to islet rejection. By transplantation of wild-type and B7.1-expressing islets into overtly diabetic mice we found that only the wild-type islets could restore normoglycemia, suggesting that costimulation by B7.1 is required in the expansion or effector phase of the response.     

Somatic spectrum of cancer-associated single basepair substitutions in the TP53 gene is determined mainly by endogenous mechanisms of mutation and by selection

The spectrum of somatic TP53 single basepair substitutions detected in 955 cancers was compared with that of 2,224 different germline mutations in 279 different human genes (other than TP53), reported as the cause of inherited disease. This comparison reveals that, disregarding a relatively small subset (12%) of TP53 mutations that probably result from the action of exogenous mutagens, both the relative rates and the nearest-neighbor spectra of single basepair substitutions are similar in the two datasets. This spectral resemblance suggests that a substantial proportion of cancer-associated somatic TP53 mutations result from endogenous cellular mechanisms. The likelihood of clinical observation of a particular mutation type differs, however, between tumors and genetic diseases, when the chemical properties of the resulting amino acid substitutions are considered. Together with a sixfold higher observation likelihood for mutations at evolutionary conserved residues, this finding argues that selection is a critical factor in determining which TP53 mutations are found to be associated with human cancer. © 1995 Wiley-Liss, Inc.     

Susceptibility testing of Danish isolates of Capnocytophaga and CDC group DF-2 bacteria

Twelve Capnocytophaga and seven DF-2 strains were tested for their susceptibility to 14 antimicrobial agents using an agar dilution and an agar diffusion method. Twenty-three other antibiotics were evaluated using the diffusion test only. All strains were fully susceptible to penicillin, ampicillin, cefuroxime, cefotaxime, erythromycin, clindamycin, chloramphenicol, doxycycline, rifamycin and ofloxacin using both methods. Clindamycin, rifamycin and cefotaxime were most active. Using agar dilution some strains were susceptible to gentamicin, but agar diffusion showed total resistance. One Capnocytophaga strain was susceptible and another moderately susceptible to metronidazole, other strains were resistant. The agar diffusion test showed that both Capnocytophaga and DF-2 were resistant to most other aminoglycosides, to fosfomycin, polymyxin and trimethoprim. All strains of both taxa were fully susceptible to piperacillin, cefoxitin, imipenem and fusidic acid and showed different susceptibilities to the other agents. Susceptibility testing by means of agar diffusion using an enriched chocolate agar and 5% CO2 atmosphere could be used to test Capnocytophaga and DF-2 strains and gives sufficient accuracy for routine use, when revised inhibition zone breakpoints are employed.     

Experimental air leaks in lung sealed by low-energy carbon dioxide laser irradiation

When a focused carbon dioxide laser beam strikes a surface of tissue, the light energy is converted instantly into thermal energy, causing cells directly in the laser's path to vaporize. Because the carbon dioxide laser's energy is well absorbed by water, this thermal effect is attenuated at a distance of 100 mu. If the laser beam is "defocused," the same thermal energy is dissipated over a larger area, causing only desiccation and melting of tissue without vaporization; however, the depth of injury remains shallow. This modified technique has been used to seal artificially created air leaks in the canine lung. Twelve mongrel dogs were anesthetized, intubated, and ventilated. The lingula was exposed sterilely through a left thoracotomy. A 1 X 3-mm hole was made in the lung at 1 cm from the edge. The created air and blood leaks were sealed with a defocused carbon dioxide laser beam set at 8 W (32 W/sq cm). Each tissue "weld" withstood 40 cm H2O of peak ventilation pressure without leak. At the time of reoperation three weeks later, there was apparent complete healing of the pulmonary surface. No air leaks were present. Histologic examination showed a small zone of amorphous coagulated pleura and lung overlying a zone of minimal atelectasis. Normal lung was present within 150 mu of the laser seal. This new technique was performed safely and easily with currently available carbon dioxide lasers in the laboratory. It is presently undergoing intraoperative trials in a controlled clinical setting.