Loren H. Hoffman

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Genetic and embryological experiments have established the Caenorhabditis elegans adult hermaphrodite gonad as a paradigm for studying the control of germline development and the role of soma-germline interactions. We describe ultrastructural features relating to essential germline events and the soma-germline interactions upon which they depend, as(More)
In Caenorhabditis elegans, specialized contractile myoepithelial cells of the somatic gonad, the gonadal sheath cells, are closely apposed to oocytes and are required for normal meiotic maturation and ovulation. Previously we found that mutations in the ceh-18 gene, which encodes a POU-class homeoprotein expressed in sheath cells, result in oocyte defects.(More)
The rabbit endometrial epithelium undergoes differentiation prior to the time of blastocyst implantation, including loss of surface negativity and a change in glycocalyx morphology. Nonpregnant (estrous) and pseudopregnant rabbits were used to study specific alterations in proteins and saccharide composition of the luminal epithelial membrane and its(More)
A glycoprotein, termed GP42, was previously identified in uterine fluid obtained from peri-implantation-stage rabbits. N-terminus amino acid sequencing of purified GP42 demonstrated identity through the first 13 amino acids with the beta subunit of liver haptoglobin. The present study was undertaken to determine if GP42 is indeed identical to haptoglobin(More)
In Drosophila, the Dorsal protein establishes the embryonic dorso-ventral axis during development. Here we show that the vertebrate homologue of Dorsal, nuclear factor-kappa B (NF-kappaB), is vital for the formation of the proximo-distal organizer of the developing limb bud, the apical ectodermal ridge (AER). Transcription of the NF-kappaB proto-oncogene(More)
The fine structure of the endometrial epithelium of the pseudo-pregnant rabbit from the day of induced ovulation (day 0) to the 13th day is here correlated with previously defined light microscopic phases. In Phase 1 (0-1 day), in which there is a presumed "priming" of the endometrium by ovarian steroidal hormones, no changes were observed. In Phase 2 (1-3(More)
Pseudopregnant, pregnant, and ovariectomized rabbits were utilized to study hormonal mediation of uterine epithelial surface negativity and glycocalyx morphology, and to seek local effects of blastocysts at sites of implantatioN. A loss of surface negativity [polycationic ferritin (PCF) binding] by day 6 of pregnancy or pseudopregnancy was noted,(More)
We used an in vitro model of human nasopharyngeal tissue in organ culture to evaluate the effects of Neisseria meningitidis on human cilia and ciliary function. Encapsulated, viable meningococci damaged ciliated epithelium of nasopharyngeal organ cultures, whereas Neisseria subflava, a commensal species, did not. Meningococcus-induced ciliary damage was due(More)