Two cases of spotted fever group rickettsiosis contracted in southern parts of Africa

The effect of Ogi-Keishi-Gomotsu-To-Ka-Kojin (OKGK), a traditional Chinese herbal medicine (Kampo medicine), on cholesterol metabolism was studied in male Sprague-Dawley rats. Intake of OKGK at doses of 1.38 g/kg for 4 weeks significantly reduced total cholesterol levels in the serum and liver of hypercholesterolemia rats fed a cholesterol-enriched diet. OKGK suppressed cholesterol absorption through the intestine and stimulated excretion of cholesterol into feces as bile acids. Biochemical study indicated that OKGK treatment enhanced cholesterol 7alpha-hydroxylase activity the rate limiting enzyme of cholic acid synthesis, in the liver without any effect on the rate limiting enzyme of cholesterol synthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Further, cholesterol-enriched diet containing cholic acid suppressed cholesterol 7alpha-hydroxylase activity, whereas OKGK administration reversed the suppression. In conclusion, these results supported the idea that OKGK may be an effective agent for treatment of patients with hypercholesterolemia.     

Effect of zinc supplementation on cell-mediated immunity and lymphocyte subsets in preschool children

The pattern and distribution of periodontitis were investigated in 162 randomly selected dogs available for necropsy in veterinary practice. There were 82 males and 80 females of 50 different breeds (150 dogs were pure-bred and 12 were mongrels, aged between 7 months and 14 yr. Presence of periodontitis was determined by assessment of alveolar bone loss on radiographs of the skulls and jaws. Periodontitis occurred frequently with increasing age, although the prevalence varied markedly among and within different breeds. Of the breeds most represented in the sample, periodontitis was most frequently seen in poodles and dachshunds but was rarely recognized in German shepherd dogs. Regardless of age, the vast majority of the dogs displayed either one or both of two different radiographic patterns of alveolar bone loss. One pattern was characterized by slight, horizontal alveolar bone loss involving interradicular and interdental areas. The other pattern was one of predominantly crater-like, or narrow, vertical bone defects which, when advanced, often extended around a single root or tooth to surround the root apices. The two types of patterns did not seem to be breed-dependent. The posterior maxillary and mandibular premolars and molars were the most frequently affected teeth. Alveolar bone loss was most severe in the maxilla, while corresponding bone loss in the mandible was more often related to increasing age.     

T lymphocyte subsets and activation status in patients following liver transplantation

Changes in T-lymphocyte subsets have previously been shown to relate to clinical events following liver transplantation and be of prognostic significance following renal transplantation. The aim of this study was to examine T lymphocyte subsets, their activation status and the mean fluorescence intensity of cell surface markers by flow cytometric analysis, in peripheral blood of patients following liver transplantation. Stable transplant patients (n=11) had a significantly higher level of activation (HLA-DR expression ) of all T cell subsets: CD3, CD4 and CD8 compared to healthy controls: 17.5% +/- 14.0 (mean +/- SD) vs 4.7 +/- 1.8 (p=0.04), 13.7% +/- 10.3 vs 4.3 +/- 1.7 (p=0.03) and 23.8% +/- 19.9 vs 3.6 +/- 2.4 (p=0.02) respectively. A further increase in activation status occurred in all T cell subsets in association with acute cellular rejection, reaching significance for the CD4+ population: 13.7% +/- 10.2 vs 23.3% +/- 20.6 (p=0.04). The mean fluorescence intensity of the CD3+DR- and CD3+ DR+ populations were increased to 1397 +/- 869 and 1282 +/- 810 following liver transplantation compared to values of 425 +/- 204 and 376 +/- 166 respectively for controls (p<0.05). T-lymphocytes maintain a high level of activation following liver transplantation and continue to express high levels of the surface marker CD3, which may account for the occurrence of acute cellular rejection despite immunosuppression in these patients.     

Lipid peroxidation and changes in T lymphocyte subsets and lymphocyte proliferative response in experimental iron overload

This study was undertaken to investigate the hypothesis that lipid peroxidation might be associated with immunological abnormalities in experimental hemosiderosis. The correlation between the degree of plasma and spleen lipid peroxidation with lymphocyte proliferative response and with the proportion of T lymphocyte subsets was studied in normal and iron overloaded male Sprague Dawley rats. The iron-loading protocol consisted of a total dose of iron-dextran (1.5 mg/Kg body weight) divided in daily i.m. injections over twenty consecutive days. Lipid peroxidation was measured by the thiobarbituric acid assay in plasma and in homogenates of spleen. Plasma lipid peroxide level increased rapidly after i.m. administration of iron-dextran and decreased sharply at 48 h after the last injection. Conversely, a progressive increase of lipid peroxidation in homogenates of spleen was observed in the course of the iron overload protocol, remaining high even at 50 days after initiation of iron-dextran injections. The increase of spleen lipid peroxide levels was associated with decreased lymphocyte proliferative response to Con A in iron overloaded rats. The addition of superoxide dismutase and catalase to lymphocyte cultures reversed the inhibition of the proliferative response, implicating reactive species of oxygen as the causative agents of these alterations. These effects may be related with the enhanced membrane and DNA damage occurring during intracellular and extracellular peroxidation. Negative correlations between helper/cytotoxic ratio and malondialdehyde levels were obtained in blood and spleen during iron administration. These results supports the hypothesis that lipid peroxidation plays a role in the immunological abnormalities observed in experimental hemosiderosis.     

Genotypic identification and phylogenetic analysis of the spotted fever group rickettsiae by pulsed-field gel electrophoresis

Using pulsed-field gel electrophoresis, we studied the chromosomes of spotted fever group rickettsiae. We digested the DNA of 16 species currently known to belong to this group with SmaI, EagI, and BssHII. The genome size of 13 rickettsiae was between 1,200 and 1,300 kb. "Rickettsia massiliae" and "R. helvetica" genome sizes were 1,370 and 1,397 kb, respectively, and that of R. bellii was 1,660 kb. It was possible to obtain distinctive patterns for each species, but in R. conorii, 10 isolates exhibited the same profiles, showing that pulsed-field gel electrophoresis is a good interspecies identification tool. We achieved a phylogenetic analysis of these bacteria by using the Dice coefficient and UPGMA and Package Philip programming. We established a dendrogram of the genetic relationships between the different species showing the existence of a cluster in the spotted fever group rickettsiae including R. conorii, R. rickettsii, R. parkeri, R. sibirica, "R. africae," "R. slovaca," Thai tick typhus rickettsia, and Israeli tick typhus rickettsia. We located three genes previously cloned and sequenced (genes encoding the R. rickettsii surface proteins of 120 and 190 kDa and the R. prowazekii citrate synthase gene), using Southern hybridization. The genes encoding citrate synthase and the surface protein of 190 kDa were usually located on the same band, and it is hypothesized that they are relatively close on the chromosome.     

Detection of T lymphocytes and T lymphocyte subsets in lichen planus: in situ and in peripheral blood

BACKGROUND: Abnormal immune mechanisms are thought to be important in the pathogenesis of lichen planus (LP). This is a study to clarify the changes that occur in T lymphocytes and T lymphocyte subsets, both in situ and in peripheral blood. METHODS: A group of 100 patients with LP were included in this study. T lymphocytes and T lymphocyte subsets were detected in lesional skin by immunoperoxidase cell surface staining using monoclonal antibodies. Peripheral T lymphocytes and T lymphocyte subsets were also detected by indirect immunofluorescence using monoclonal antibodies. A group of 10 normal healthy subjects were used as controls. RESULTS: The study of the lesional T lymphocytes and T lymphocyte subsets demonstrated that helper T cells was the predominant subset in LP lesions in most of the patients. This predominance was evident irrespective of the duration of the disease and was more evident in late than in early lesions. The percentage of both total T lymphocytes and helper T cells in peripheral blood was decreased significantly in patients compared with controls. A significant decrease in helper T cells and the helper/cytotoxic T cell ratio was detected in patients with a longer duration of the disease. CONCLUSION: Activation of helper T lymphocytes that were found to be the predominant subsets in LP lesions may be responsible for epidermotropic cellular infiltrates leading to damage and destruction of epidermal cells.     

Azithromycin in the prevention of Mediterranean spotted fever

Antibodies to Rickettsia conorii were detected by the indirect immunofluorescence (IFA) assay in 64 (51.6%) out of 124 examinees living in North Dalmatia (Croatia) who had a history of recent tick bites during 1994 and 1995. Positive titers of IFA antibodies to R. conorii were detected in 12 (31.5%) out of 38 examinees with carried out prophylaxis by azithromycin. The usual clinical signs of Mediterranean spotted fever were registered in 22 (25.6%) and asymptomatic infection in 30 (34.8%) out of 86 examinees without prophylaxis. Clinical signs of the disease were not registered in examinees with prophylaxis.     

Taxonomic relationships among spotted fever group rickettsiae as revealed by antigenic analysis with monoclonal antibodies

The spotted fever group (SFG) is made up of more than 20 different rickettsial species and strains. Study of the taxonomic relationships among the group has been attempted by phenotypic, genotypic, and phylogenetic analyses. In this study, we determined taxonomic relationships among the SFG rickettsiae by comparative analysis of immunogenic epitopes reactive against a panel of monoclonal antibodies. A total of 98 monoclonal antibodies, which were directed against epitopes on the major immunodominant proteins or on the lipopolysaccharide-like antigens of strains of Rickettsia africae, Rickettsia conorii, Rickettsia massiliae, Rickettsia akari, Rickettsia sibirica, and Rickettsia slovaca, were used in the study. The distribution and expression of the epitopes among 29 SFG rickettsiae and Rickettsia bellii were assessed by determination of reaction titers in a microimmunofluorescence assay. The results were scored as numerical taxonomic data, and cluster analysis was used to construct a dendrogram. The architecture of this dendrogram was consistent with previous taxonomic studies, and the implications of this and other findings are discussed.     

Cutaneous histopathology of Rocky Mountain spotted fever

The dermatologic diagnosis of Rocky Mountain spotted fever (RMSF) is often presumptive; the clinical presentation includes skin rash and febrile illness with or without a clear history of tick bite. The characteristic cutaneous manifestations include a generalized skin eruption with purpuric, blanching or non-blanching macules and papules usually involving the extremities. Although skin biopsies are often performed to confirm the diagnosis, the spectrum of cutaneous histopathology in RMSF has not been well described. We studied a series of 26 cases of RMSF, of which 10 were surgical specimens and 16 were autopsies. The microscopic changes were correlated with the duration of illness. The main histopathologic feature was lymphohistiocytic capillaritis and venulitis with extravasation of erythrocytes, edema, predominantly perivascular and some interstitial infiltrate. Leukocytoclastic vasculitis (LCV) with neutrophilic infiltrate and nuclear dust was seen in 11 of 15 (73%) specimens from involved skin. These lesions with LCV also showed notable epidermal change including basal layer vacuolar degeneration with mild dermoepidermal interface lymphocytic exocytosis. Six lesions with LCV displayed focal fibrin thrombi and capillary wall necrosis. Apoptotic keratinocytes were noted in 3 lesions with LCV. Subepidermal blister was observed in the skin lesion of an autopsied patient with LCV changes. Another lesion of a fatal case with LCV also contained features of acute neutrophilic eccrine hidradenitis. Focal small nerve twig inflammation was noted in a third autopsy case with LCV. Plasma cells were seen in 6 of 34 specimens (18%); and eosinophils were observed in 3 (9%). The subcutaneous fat contained a mild perivascular inflammation and one case revealed focal lobular neutrophilic inflammation. Immunohistologic (IH) staining using polyclonal rabbit anti-Rickettsia rickettsii demonstrated positive staining of the organisms in the affected endothelial cells in all 12 cases tested. The cutaneous histopathology of RMSF is caused by endothelial damage by the rickettsial organisms which elicit an initial lymphohistiocytic small vessel vasculitis with progression to LCV. The vasculitis in RMSF is, therefore, considered to be a form of septic vasculitis.     

Identification of lymphocyte subsets in pregnancy gingivitis

The percentage of gingival tissue and peripheral T, T Subsets and B lymphocytes were assessed in ten pregnant women during the first, second and third trimesters. Clinically the gingival index (GI) was found to be higher during pregnancy than in the control group. The percentage of the T3, T4 and B cells appeared to decrease in peripheral blood and gingival tissues during pregnancy as compared to control group.     

Isolation of a spotted fever group rickettsia from the Pacific Coast tick, Ixodes pacificus, in Oregon

A rickettsia of the spotted fever group was isolated on three occasions from Ixodes pacificus in western Oregon. These isolations, and additional evidence furnished by complement fixation tests on guinea pigs inoculated with other Oregon ticks of this species, indicate that the association of this rickettsia with the Pacific Coast tick may be widespread. This is the first isolation of a spotted fever group rickettsia from I. pacificus. Because the Oregon isolates are mildly virulent for guinea pigs they resemble the Western U and Rickettsia montana strains of rickettsiae. However, preliminary evidence from cross-immunofluorescence tests of mouse antisera suggests the Tillamook and Grants Pass strains are antigenically different from all known spotted fever group agents.     

Identification of gamma delta T lymphocyte subsets that populate calf ileal mucosa after birth

Ileal intraepithelial and lamina propria lymphocytes from newborn, 1.5-week-old, and 3-week-old calves were compared to determine to what extent the mucosa becomes populated after birth. Single and dual fluorescence flow cytometry were used with monoclonal antibodies to bovine (Bo) CD molecules to identify lymphocyte subpopulations. Few ileal mucosal lymphocytes were present in calves at birth. However, by 1.5 weeks of age, the villi were populated with large numbers of lymphocytes, and by 3 weeks of age, the numbers had increased further. These included a prominent subpopulation of gamma delta T cells. Several subsets of gamma delta T cells populated ileal mucosa after birth. The predominant subset coexpressed BoCD2, and a smaller subset coexpressed BoCD8. WC1+ gamma delta T cells comprised the smallest subset. All gamma delta T cell subsets coexpressed ACT2, a molecule expressed on activated WC1+ and WC1- gamma delta T cells from cattle.     

Intellectual sequelae of Rocky Mountain spotted fever.

Administered the WISC, Marianne Fostig Developmental Test of Visual Perception, and Bender-Gestalt Test to 12 6-15 yr. old former Rocky Mountain spotted fever (RMSF) patients and 12 matched controls. Significant differences were obtained on 7 of 13 WISC scales and on 2 of 5 Fostig subsets. However, no differences were found on the Bender-Gestalt. It is concluded that RMSF exerts a mild but consistent effect on intellectual functioning. This in turn suggests a higher probability of learning disability and corresponding difficulty with school performance in former RMSF patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interaction of lactoferrin, monocytes, and T lymphocyte subsets in the regulation of steady-state granulopoiesis in vitro

Colony-stimulating activities (CSA) are potent granulopoietic stimulators in vitro. Using clonogenic assay techniques, we analyzed the degree to which mononuclear phagocytes and T lymphocytes cooperate in the positive (production/release of CSA) and feedback (inhibition of CSA production/release) regulation of granulopoiesis. We measured the effect of lactoferrin (a putative feedback regulator of CSA production) on CSA provision in three separate assay systems wherein granulocyte colony growth of marrow cells from 22 normal volunteers was stimulated by (a) endogenous CSA-producing cells in the marrow cells suspension, (b) autologous peripheral blood leukocytes in feeder layers, and (c) medium conditioned by peripheral blood leukocytes. The CSA-producing cell populations in each assay were varied by using cell separation techniques and exposure of isolated T lymphocytes to methylprednisolone or to monoclonal antibodies to surface antigens and complement. We noted that net CSA production increased more than twofold when a small number of unstimulated T lymphocytes were added to monocyte cultures. Lactoferrin's inhibitory effect was also T lymphocyte dependent. The T lymphocytes that interact with monocytes and lactoferrin to inhibit CSA production are similar to those that augment CSA production because their activities are neither genetically restricted not glucocorticoid sensitive, and both populations express HLA-DR (Ia-like) and T3 antigens but not T4 or T8 antigens. These findings are consistent with results of our studies on the mechanism of lactoferrin's inhibitory effect with indicate that mononuclear phagocytes produce both CSA and soluble factors that stimulate T lymphocytes to produce CSA, and that lactoferrin does not suppress monocyte CSA production, but does completely suppress production or release by monocytes of those factors that stimulate T lymphocytes to produce CSA. We conclude that mononuclear phagocytes and a subset of T lymphocytes exhibit important complex interactions in the regulation of granulopoiesis.     

Differential activity of P-glycoprotein in normal blood lymphocyte subsets

To better understand the phenomenon of P-glycoprotein (P-170) expression we investigated lymphocyte subpopulations for P-170 function in healthy volunteers. Studies were based on three-colour flow cytometry including the fluorescent probe rhodamine 123 (Rh123), which is transported by P-170. Marked Rh123 efflux was detected in CD8+ T lymphocytes with CD8+/CD45RA+ T cells (naive cells) showing significantly higher P-170 activity as compared with CD8+/CD45RA- cells (P<0.04). Vice versa, CD8+/CD45RO+ T cells (memory cells) demonstrated less P-170 activity than CD8+/CD45RO- cells (P<0.04). P-170 function was less prominent in CD4+ T cells, however, Rh123 efflux was higher in the CD4+/CD45RA+ and CD4+/CD45RO- subpopulations (P<0.025) corresponding to the CD8+ results. Dye efflux differed significantly between activated and non-activated CD8+ and CD4+ as well as CD8+/CD11b+ and CD8+/CD11b- T lymphocytes. Since CD16+ natural killer cells (NK) expressed the highest level of P-170, the NK cytotoxicity against 51Cr-labelled K562 target cells was assayed in the presence or absence of P-170 inhibitors. NK related cytotoxicity was significantly reduced in the presence of R-verapamil and dexnigaldipine-HCP in a dose-dependent manner. The differential expression of P-170 activity in naive and memory T cells together with the reduced NK related cytotoxicity in the presence of MDR-modulators suggest a physiological role of P-170 in immunological functions of these lymphocyte subsets. Consequently, the addition of MDR modulators to conventional chemotherapy as a strategy to overcome drug resistance should consider possible adverse immunosuppressive effects.     

The expression of HLA, Epstein-Barr virus nuclear antigen and the infiltration of T lymphocyte subsets in nasopharyngeal biopsy tissues

In this study, 79 patients with locally advanced head and neck cancer were treated with induction chemotherapy. Cisplatin, 25 mg/m2, and 5-fluorouracil (5-FU), 1000 mg/m2, were employed, both of them in 24-hour continuous infusion over 96 hours, four cycles. The patients later underwent surgery and/or radiation therapy. The response to chemotherapy was 49%: of the complete responses (CR), 56% were histological; 29% were partial responses (PR). With the administration of the fourth cycle, CR increased from 30% to 49%. Once the complete treatment had been finished, 75% of CR and 5% PR were achieved. With a maximum follow-up period of 44 months, overall survival stands at 50%.     

Persistent long-term changes in lymphocyte subsets induced by polyclonal antibodies

BACKGROUND: Clinicians are well aware of the short-term effects of immunosuppression by mono- or polyclonal antibodies. Little is known about long-term changes induced by these therapies. METHODS: Forty-three renal allograft recipients were selected according to their initial postoperative immunosuppression: (1) BI group=basic immunosuppression with steroids and cyclosporine, n=16; (2) ATG group=basic immunosuppression plus polyclonal antibody antithymocyte globulin (ATG), n=11; and (3) OKT3 group=basic immunosuppression plus monoclonal antibody OKT3, n=16 patients. At intervals of 6 months, the following parameters were measured prospectively: lymphocyte surface antigens (HLA-DR, CD3, CD4, CD8, CD16, CD19, CD56, and CD57); serum and urine neopterin; serum amyloid A; and indirect and direct tests for herpes viruses. RESULTS: The mean period of observation was 58.4 months. The most significant differences between the groups occurred for CD4+ and CD8+ T cells. The ratios of CD4+ to CD8+ cells (n=278 measurements) were significantly and persistently lower in the ATG group (P<0.001, Brown-Mood test). Five years after transplantation, the ATG group had a CD4+ to CD8+ cell ratio of x=0.6 versus x=1.7 in the OKT3 group and x=2.0 in the BI group. This inversion was due to a persistent depletion of the CD4+ cells and an increased regeneration of the CD8+ cells, in particular of the CD8+brightCD57+ subpopulation. Extent and duration of CD4+ depletion correlated with the cumulative ATG dose (r=0.7, P<0.05, Spearman rank correlation test). CONCLUSION: Therapy with polyclonal antibody ATG induces dose-dependent long-term changes in T-cell lymphocyte subsets, which persist over a period of years.     

First isolation of a rickettsia closely related to Japanese spotted fever pathogen from a tick in Japan

In May 1993, we collected unfed ticks in Anan, Tokushima Prefecture, Shikoku District, Japan, a highly endemic area of Japanese spotted fever (JSF). We isolated JSF rickettsiae from these ticks by inoculating tick-emulsions into L-929 cells. Of the four genera and seven species of ticks examined, only one larva of Dermacentor taiwanensis Sugimoto yielded a rickettsial isolate. The isolate (DT-1 strain) was found to belong to the serotype common to the causative agent of JSF. This was based on its specific reactivity to mouse antisera and to a monoclonal antibody to JSF rickettsiae from the Shikoku District. This is the first tick-borne spotted fever group of rickettsia isolated in Japan. However, all stages of D. taiwanensis infrequently parasitize humans. Some ticks in the genus Haemaphysalis commonly infest humans and are frequently found to be rickettsia-positive in the hemolymph test when using the monoclonal antibody mentioned above. Therefore, the vectors of JSF rickettsiae to humans may be a complex of tick species.