Neonatal alloimmune thrombocytopenia after maternal immunization with paternal mononuclear cells: successful treatment with intravenous gamma globulin.

We report a case of neonatal alloimmune thrombocytopenia and intracranial hemorrhage in an infant whose mother received immunizations of paternal mononuclear cells. This therapy is designed to prevent unexplained first trimester miscarriages. No previous cases of platelet autoimmunization associated with maternal immunization with paternal mononuclear cells has been reported. Treatment with antenatal maternal infusions of intravenous gamma globulin (IVGG) did not prevent fetal thrombocytopenia, but IVGG may become the treatment of choice for postnatal, antibody-mediated thrombocytopenia of the newborn.     

Determinants of CD4 Counts Among HIV-Negative Ethiopians: Role of Body Mass Index,Gender, Cigarette Smoking,Khat (<Emphasis Type="Italic">Catha Edulis</Emphasis>) Chewing,and Possibly Altitude?

To study the determinants of CD4% and CD4 counts among HIV-negative Ethiopians, and to identify factors susceptible to explain the low CD4 counts observed among Ethiopian subjects. Cohort studies among factory workers in Akaki and Wonji, Ethiopia. Clinical and laboratory examinations, including determination of HIV serological status and T-cell subsets, were performed during follow-up visits every six months. In addition, micronutrients (retinol, carotenoids, tocopherol, transferrin receptor, and selenium) plasma concentrations were determined in a subset of 38 HIV-positive and 121 HIV-negative participants. HIV-negative participants with at least one CD4 count measurement were 157 females in Akaki, 203 males in Akaki, and 712 males in Wonji. CD4 counts were independently and positively associated with body mass index (through an increase in lymphocyte counts), female gender (through an increase in CD4%), cigarette smoking (through an increase in CD4%), khat chewing (through an increase in both lymphocyte counts and CD4%), and Akaki study site (through a large increase in lymphocyte counts compensating a decrease in CD4%). Intestinal parasitic infections were not associated with CD4% or CD4 counts. Retinol, carotenoids, and -tocopherol plasma concentrations decreased with HIV infection and advancing immunosuppression, but were not associated with CD4 counts among HIV-negative subjects. Low body mass index among Ethiopians may have contributed to their overall low CD4 counts. Other factors remain to be elucidated.     

Immunohematological reference ranges for adult Ethiopians

A cross-sectional survey was carried out with 485 healthy working adult Ethiopians who are participating in a cohort study on the progression of human immunodeficiency virus type 1 (HIV-1) infection to establish hematological reference ranges for adult HIV-negative Ethiopians. In addition, enumeration of absolute numbers and percentages of leukocyte subsets was performed for 142 randomly selected HIV-negative individuals. Immunological results were compared to those of 1,356 healthy HIV-negative Dutch blood donor controls. Immunohematological mean values, medians, and 95th percentile reference ranges were established. Mean values were as follows: leukocyte (WBC) counts, 6.1 x 10(9)/liter (both genders); erythrocyte counts, 5.1 x 10(12)/liter (males) and 4.5 x 10(12)/liter (females); hemoglobin, 16.1 (male) and 14.3 (female) g/dl; hematocrit, 48.3% (male) and 42.0% (female); platelets, 205 x 10(9)/liter (both genders); monocytes, 343/microl; granulocytes, 3, 057/microl; lymphocytes, 1,857/microl; CD4 T cells, 775/microl; CD8 T cells, 747/microl; CD4/CD8 T-cell ratio, 1.2; T cells, 1, 555/microl; B cells, 191/microl; and NK cells, 250/microl. The major conclusions follow. (i) The WBC and platelet values of healthy HIV-negative Ethiopians are lower than the adopted reference values of Ethiopia. (ii) The absolute CD4 T-cell counts of healthy HIV-negative Ethiopians are considerably lower than those of the Dutch controls, while the opposite is true for the absolute CD8 T-cell counts. This results in a significantly reduced CD4/CD8 T-cell ratio for healthy Ethiopians, compared to the ratio for Dutch controls.     

Anti-adaptors provide multiple modes for regulation of the RssB adaptor protein

RpoS, an RNA polymerase σ factor, controls the response of Escherichia coli and related bacteria to multiple stress responses. During nonstress conditions, RpoS is rapidly degraded by ClpXP, mediated by the adaptor protein RssB, a member of the response regulator family. In response to stress, RpoS degradation ceases. Small anti-adaptor proteins—IraP, IraM, and IraD, each made under a different stress condition—block RpoS degradation. RssB mutants resistant to either IraP or IraM were isolated and analyzed in vivo and in vitro. Each of the anti-adaptors is unique in its interaction with RssB and sensitivity to RssB mutants. One class of mutants defined an RssB N-terminal region close to the phosphorylation site and critical for interaction with IraP but unnecessary for IraM and IraD function. A second class, in the RssB C-terminal PP2C-like domain, led to activation of RssB function. These mutants allowed the response regulator to act in the absence of phosphorylation but did not abolish interaction with anti-adaptors. This class of mutants is broadly resistant to the anti-adaptors and bears similarity to constitutively activated mutants found in a very different PP2C protein. The mutants provide insight into how the anti-adaptors perturb RssB response regulator function and activation.     

Ixodid ticks infesting cattle in three agroecological zones in central Oromia: species composition,seasonal variation,and control practices

A cross-sectional study was conducted to determine the species, prevalence, and seasonal variation of ticks on cattle in central Oromia. In addition, questionnaire survey was used to assess the control practices of ticks in central Oromia. During the study period from August 2008 through April 2009, a total of 10,440 adult ixodid ticks were collected from a total of 918 cattle (153 cattle during dry and wet seasons from each of three agroecologies) in three agroecological zones during wet and dry seasons. A total of seven species of ixodid ticks belonging to four genera were identified during the wet period, whereas similar numbers of genera but six species of ixodid ticks were recorded during the dry season. Amblyomma, Boophilus, Rhipicephalus, and Hyalomma tick genera were identified during the two seasons. Five different species of ticks were identified from the highland altitude. Significantly (p?<?0.05) higher proportion of Boophilus decoloratus (88.2 %) was identified during the wet season, Hyalomma truncatum (1.5 %) was with the least proportion. Rhipicephalus evertsi evertsi (50.8 %) was the most abundant during the dry period, whereas Hyalomma marginatum rufipes (5 %) was with smallest proportion. In the midland, a total of six species of ticks were identified. Significantly (p?<?0.05) higher proportion of Amblyomma variegatum (76.6 %) than the other species was recorded during the wet season in the midland. But Rhipicephalus pulchellus (0.05 %) was collected with the lowest proportion. R. e. evertsi (46.3 %) was the most abundant tick species during the dry season, whereas R. pulchellus (0 %) was with lowest proportion. In the lowland, a total of seven species of ticks during the wet and six during the dry season were identified. A significantly (p?<?0.05) higher proportion of A. variegatum (30.3 %) was recorded during the wet season, whereas R. pulchellus (1.4 %) was identified with the lowest proportion in the lowland. R. e. evertsi (24.8 %) was the most abundant tick species during the dry season in the lowland, but R. pulchellus (0 %) was with the lowest proportion during the same season in the lowland. Results of the study revealed that the highest mean total tick burden was recorded during the early rainy season than the dry season from the end of March to April. And the lowest mean tick count was recorded during the early dry and the late dry season during December and February, respectively. The overall tick count across seasons showed significant variation (F?=?114 and p?=?0.000). The questionnaire survey on the tick control practices has revealed that (90 %) diazinon and (57.3 %) cypermethrin were the commonly used acaricides with a frequency of one to three times per year during the peak of tick infestation. In conclusion, this study demonstrated that ixodid ticks occur with high prevalence and burden and still play major roles in reducing productivity of cattle and cause health problems of cattle in central Oromia. Further studies on the role of ticks in the transmission of pathogens to cattle, other animals, and zoonotic pathogens to man in Oromia are urgently needed.     

Platelet kinetics in patients with idiopathic thrombocytopenic purpura and moderate thrombocytopenia

We studied ten normal subjects and 20 patients with stable, untreated idiopathic thrombocytopenic purpura (ITP) and platelet counts in the range of 35,000 to 110,000/microL. The diagnosis was made by clinical criteria. Platelet-associated IgG was increased in all nine of the nine patients studied. Autologous platelets were labeled with chromium 51 and reinfused for measurement of mean cell life and platelet production rate. Mean cell life was calculated by two methods, weighted mean and multiple hit, with excellent agreement between the two. As expected, mean cell life was significantly reduced in ITP patients as compared to the normal subjects (2.9 days v. 8.0 days, P less than .001). However, mean platelet production rates in ITP patients and normal subjects, 3.5 and 3.8 X 10(9) platelets/k/d respectively, were not significantly different. Platelet production rate was above and below the normal range (2 to 5.6 X 10(9) platelets/k/d) in two and four patients, respectively. We conclude that the rate of platelet production is not increased in most patients with ITP who have platelet counts greater than 35,000/microL. We did find that platelet size was increased in eight of the 12 patients in whom it was measured, including two of the patients with low platelet production.     

In vivo expression of the B7 costimulatory molecule by subsets of antigen-presenting cells and the malignant cells of Hodgkin's disease

The B-lymphocyte/accessory-cell activation antigen B7 (BB1) has been shown in vitro to stimulate T-lymphocyte proliferation and cytokine production via CD28 present on the latter cells. In this study, benign lymphoid tissues, lymphomas, and extralymphoid inflammatory sites were examined immunohistochemically using anti-B7 and other relevant monoclonal antibodies. B7 was expressed by benign transformed germinal center B cells, as it was by B cells of follicular lymphomas. B7 was also expressed by a subpopulation (a mean of 31% to 65%) of macrophages and dendritic cells in a variety of lymphoid tissues. It was present in abundance on all macrophages constituting sarcoid granulomas in lymph nodes. In extralymphoid inflammation, 17% to 35% of macrophages expressed B7 only weakly. Cases of Hodgkin's disease showed expression of B7 by the majority of Reed-Sternberg cells or malignant mononuclear variants, a phenomenon that potentially contributes to the lymphocytic accumulation that is a feature of this condition. CD28+ T cells were seen in all areas where T cells were present. B7+ and CD28+ cells colocalized in, for example, lymphoid follicles, lymph node paracortex, sarcoid granulomas, and Hodgkin's disease tissue, indicating a potential for cellular interaction via these molecules at these sites.