Clonal hematopoiesis and acquired thalassemia in common variable immunodeficiency

The Drosophila hairy gene encodes a basic helix-loop-helix protein that functions in at least two steps during Drosophila development: (1) during embryogenesis, when it partakes in the establishment of segments, and (2) during the larval stage, when it functions negatively in determining the pattern of sensory bristles on the adult fly. In the rat, a structurally homologous gene (RHL) behaves as an immediate-early gene in its response to growth factors and can, like that in Drosophila, suppress neuronal differentiation events. Here, we report the genomic cloning of the human hairy gene homolog (HRY). The coding region of the gene is contained within four exons. The predicted amino acid sequence reveals only four amino acid differences between the human and rat genes. Analysis of the DNA sequence 5' to the coding region reveals a putative untranslated exon. To increase the value of the HRY gene as a genetic marker and to assess its potential involvement in genetic disorders, we sublocalized the locus to chromosome 3q28-q29 by fluorescence in situ hybridization.     

Nuclear counterparts of the cytoplasmic mitochondrial 12S rRNA gene: a problem of ancient DNA and molecular phylogenies

Monkey mummy bones and teeth originating from the North Saqqara Baboon Galleries (Egypt), soft tissue from a mummified baboon in a museum collection, and nineteenth/twentieth-century skin fragments from mangabeys were used for DNA extraction and PCR amplification of part of the mitochondrial 12S rRNA gene. Sequences aligning with the 12S rRNA gene were recovered but were only distantly related to contemporary monkey mitochondrial 12S rRNA sequences. However, many of these sequences were identical or closely related to human nuclear DNA sequences resembling mitochondrial 12S rRNA (isolated from a cell line depleted in mitochondria) and therefore have to be considered contamination. Subsequently in a separate study we were able to recover genuine mitochondrial 12S rRNA sequences from many extant species of nonhuman Old World primates and sequences closely resembling the human nuclear integrations. Analysis of all sequences by the neighbor-joining (NJ) method indicated that mitochondrial DNA sequences and their nuclear counterparts can be divided into two distinct clusters. One cluster contained all temporary cytoplasmic mitochondrial DNA sequences and approximately half of the monkey nuclear mitochondriallike sequences. A second cluster contained most human nuclear sequences and the other half of monkey nuclear sequences with a separate branch leading to human and gorilla mitochondrial and nuclear sequences. Sequences recovered from ancient materials were equally divided between the two clusters. These results constitute a warning for when working with ancient DNA or performing phylogenetic analysis using mitochondrial DNA as a target sequence: Nuclear counterparts of mitochondrial genes may lead to faulty interpretation of results.     

One-step needle aspiration and lavage for the treatment of abdominal and pelvic abscesses

OBJECTIVE: This retrospective study was undertaken to show the efficacy and safety of one-step needle aspiration and lavage for the treatment of nonenteric, nonpancreatic abdominal and pelvic abscesses. MATERIALS AND METHODS: Eighty-two nonconsecutive patients (age range, 4-81 years old) with 97 abdominal and pelvic abscesses were treated over 16 years with a one-step percutaneous needle aspiration and lavage technique. Abscesses were drained with sonographic or CT guidance in a single session. An 18-gauge needle was used for aspiration and repeated saline lavage; no drainage catheter was left in place. For collections that appeared multiloculated, needle repositioning and repeated aspiration and lavage were performed during the single session. All patients received i.v. antibiotics. RESULTS: Eighty-seven (90%) of 97 abscesses in 72 of 82 patients were successfully treated, including 17 (85%) of 20 abscesses that were multiloculated. The only two complications were transient sepsis in one patient and hemorrhage in one patient that resolved with transfusion and conservative treatment. Needle aspiration and lavage failures were associated with diffuse peritonitis, occult malignancy, unsuspected enteric communication, and a dropped surgical clip. CONCLUSION: Percutaneous needle aspiration and lavage can be a safe, effective alternative to the more conventional treatment of prolonged catheter drainage. In selected patients, including certain patients with multiloculated abscesses, one-step needle aspiration and lavage should be considered as the initial method of treatment.     

Receptors for the 5-oxo class of eicosanoids in neutrophils

5-Hydroxy- and 5-oxo-eicosatetraenoate (5-HETE and 5-oxoETE) activate polymorphonuclear neutrophils (PMNs) through a common, receptor-like recognition system. To define this system, we examined the interaction of these eicosanoids with human PMNs. PMNs esterified 5-[3H]HETE to glycerolipids at 37 and 4 degreesC. At 37 but not 4 degreesC, the cells also hydroxylated the label to 5, 20-[3H]diHETE. The acyl:CoA synthetase blocker, triacsin C, inhibited esterification but also led to an increase in the hydroxylation of the label. PMNs processed 5-[3H]oxoETE through the same pathways but only or principally after reducing it to 5-[3H]HETE (37 or 4 degreesC). In the presence of these varying metabolic reactions, PMNs (37 or 4 degreesC; +/- triacsin C) could not be shown to receptor bind either radiolabel. Plasma membranes isolated from PMNs esterified but unlike whole cells did not reduce or hydroxylate 5-[3H]oxoETE. Triacsin C blocked esterification, thereby rendering the membranes unable to metabolize this radiolabel. Indeed, triacsin C-treated membranes bound (Kd = 3.8 nM) 5-[3H]oxoETE specifically and reversibly to 86 pmol of sites per 25 micrograms of membrane protein. 5-OxoETE, 5-HETE, and 5,15-diHETE displaced this binding at concentrations correlating with their potency in eliciting PMN Ca2+ transients. GTP and GTPgammaS, but not ATP or ATPgammaS, also reduced 5-[3H]oxoETE binding, whereas 15-HETE, leukotriene B4, platelet-activating factor, IL-8, C5a, and N-formyl-Met-Leu-Phe lacked this effect. We conclude that PMNs and their plasma membranes use an acyl:CoA synthetase-dependent route to esterify 5-HETE and 5-oxoETE into lipids. Blockade of the synthetase uncovers cryptic plasmalemma sites that bind 5-oxoETE with exquisite specificity. These sites apparently mediate responses to the 5-oxo class of eicosanoids and are likely members of the serpentine superfamily of G protein-linked receptors.     

Distribution of iatrogenic retinal breaks in macular hole surgery

BACKGROUND: Intraoperative peripheral iatrogenic retinal breaks can be a serious complication of vitreous surgery. This study was undertaken to determine whether vitreous surgical techniques used for macular hole surgery were associated with a different incidence or distribution of retinal breaks. METHODS: The authors prospectively evaluated a series of 181 consecutive eyes undergoing macular hole surgery. Contemporaneous reporting of intraoperative and postoperative retinal breaks and postoperative retinal detachments was performed. Comparison was made to historic controls of two case series of patients undergoing vitreous surgery for other indications. RESULTS: Of 181 eyes, 10 (5.5%) had 15 intraoperative retinal breaks. Of the 15 breaks, 3 (20%) were in the quadrant near the surgeon's right-hand sclerotomy, 9 (60%) were in the two inferior quadrants, and 11 (73%) were in the two temporal quadrants. By comparison to previously reported case series, tears in our series were less likely to be near the right-hand sclerotomy (P = 0.00055) and more likely to occur in the two inferior retinal quadrants (P = 0.00015) and two temporal retinal quadrants (P = 0.0042). Two patients (1.1%) of 181 had postoperative retinal detachments. CONCLUSIONS: Patients undergoing vitreous surgery for macular hole have a similar incidence but different location of iatrogenic retinal breaks when compared with patients undergoing pars plana vitrectomy for other indications. These breaks are not distributed near sclerotomy sites and tend to be in the inferior and temporal retina. This establishes the need for greater intraoperative surveillance in these areas.