Angiolymphoid hyperplasia with eosinophilia mimicking multiple cylindromas: a rare case report

Angiolymphoid hyperplasia with eosinophilia (ALHE) is a rare and idiopathic vascular disorder. It is characterized by red to brown papules and nodules, typically localized on the head and neck, particularly around the ear as singular or multiple lesions. Although ALHE is a benign disease, lesions are often persistent and difficult to eradicate. Young to middle age women are more commonly affected. The histological examination corresponds to a florid vascular proliferation with atypical endothelial cells surrounded by a lymphocytic and eosinophilic infiltrate. We describe an elderly male with multiple nodular lesions over the scalp mimicking cylindromas; the histological examination was consistent with ALHE.

Neglected Basal cell carcinoma in axilla

Basal cell carcinoma (BCC) is the most common skin cancer. The most significant risk factor is ultraviolet radiation and the most frequent site of BCC is head and neck, with around 75–80% occurring on face. BCC occurs infrequently in non-sun-exposed skin. The axilla is one of the least sun-exposed areas of our body, and as such BCC at this site is very rare. We present a case of large neglected axillary BCC in a 35- year-old male.

Corticosteroid Induced, HHV-8 Positive Kaposi's Sarcoma in a Non-HIV Elderly Patient

Kaposi’s sarcoma (KS) was first described in 1872 by Moritz Kaposi. In 1994, Chang et al. first identified DNA sequences corresponding to human herpesvirus-8 (HHV-8) in AIDS-associated Kaposi sarcoma biopsies. It is now believed that presence of HHV-8 is necessary but not sufficient to cause KS. Other factors like immunosuppressive therapy also play a role. We describe an HIV-negative elderly patient who developed KS of skin and mucous membrane after prolonged use of corticosteroids for knee pain. The patient was positive for HHV-8.

YY1 represses beta-casein gene expression by preventing the formation of a lactation-associated complex

Site-specific mutagenesis of the highly conserved milk box (-140 to -110) region suggested that beta-casein expression is regulated by a hormone-mediated relief of repression (M. Schmitt-Ney, W. Doppler, R. K. Ball, and B. Groner, Mol. Cell. Biol. 11:3745-3755, 1991). However, when this sequence was placed upstream of a heterologous thymidine kinase promoter, it activated reporter gene expression. This apparent paradox was resolved when the trans-acting factor YY1, capable of acting as both a positive and negative regulator, was shown to interact with the milk box region, using bacterially expressed YY1 and specific oligonucleotide and antibody competition experiments. Second, it was demonstrated that extracts prepared from several cell types contained a protein(s) interacting with the mammary gland-specific factor (MGF) binding site, previously shown to be required for beta-casein promoter activity (Schmitt-Ney et al., Mol. Cell. Biol. 11:3745-3755, 1991). Sequence analysis of this site revealed similarity to the gamma interferon-activated sequence, suggesting that MGF may be related to the stat91 signaling protein. Finally, using an oligonucleotide encompassing both the YY1 and MGF sites, we detected a slow-mobility complex only in extracts from mammary glands at late pregnancy and lactation (lactation-associated complex [LAC]). Site-specific mutation of the YY1 binding site led to an enhancement in LAC DNA binding activity, while mutation of the MGF site decreased detectable LAC. These results support a model in which lactogenic stimuli lead to a decrease in YY1 binding, and subsequent increased formation of LAC at a nearby binding site, to stimulate beta-casein transcription.

Reduced levels of hsp90 compromise steroid receptor action in vivo

Signalling by steroid hormones is mediated by receptor proteins that bind hormonal ligands and regulate the transcription of specific genes. The heat-shock protein hsp90 seems to associate selectively with unliganded receptors (aporeceptors), but it has not been determined whether this interaction affects receptor function in vivo. To address the role of hsp90, we have taken advantage of the capacity of mammalian steroid receptors to function in yeast. We constructed a strain of Saccharomyces cerevisiae in which hsp90 expression was regulatable and could be reduced more than 20-fold relative to wild type. At low levels of hsp90, aporeceptors seem to be mostly hsp90-free, yet fail to enhance transcription; on hormone addition, the receptors are activated but with markedly reduced efficiency. Thus hsp90 does not inhibit receptor function solely by steric interference; rather, hsp90 seems to facilitate the subsequent response of the aporeceptor to the hormonal signal. This is the first biological evidence that hsp90 acts in the signal transduction pathway for steroid receptors.

Barley alpha-amylase genes and the thiol protease gene Aleurain: use of a single poly(A) addition signal associated with a conserved pentanucleotide at the cleavage site

Plant genes usually have multiple potential poly(A) addition signals, and different sites are used for 3' processing of transcripts from a single gene. In contrast, we show here that four barley genes that also have multiple poly(A) addition signals conforming to the plant consensus use only one signal. In each of these genes, the region of cleavage for poly(A) addition is centered on a conserved pentanucleotide. This AGGCA is followed by a conserved sequence homologous to sequences involved in self-cleavage of plant viroid RNA precursors; immediately following, in turn, are four or five nucleotides complementary to the nucleotides immediately preceding AGGCA in each gene. The presence of these conserved sequences and their association with a single region for poly(A) addition in three different gene types (high-pI and low-pI alpha-amylase genes and a thiol protease) that otherwise are not homologous in their 3' untranslated/flanking sequences suggest that they might participate in some common regulatory mechanism shared by these genes.

Barley alpha-amylase genes. Quantitative comparison of steady-state mRNA levels from individual members of the two different families expressed in aleurone cells

We have cloned and sequenced two barley alpha-amylase genes belonging to the high pI isozyme family, one of which, Amy6-4, corresponds to a cDNA previously characterized by our laboratory. A 750-base pair probe from Amy6-4, representing primarily the promoter/upstream sequences cross-hybridizes on genomic Southern blots under stringent conditions to five other genes or pseudogenes; this demonstrates that the promoter/upstream region in these different members of the gene family is highly conserved. In contrast, this probe hybridizes very poorly to the genomic fragment containing the other cloned high pI gene, Amy46, a finding consistent with substantial divergence of sequence about 200 base pairs upstream from the TATA box of each. We compared steady-state mRNA levels from these individual genes to levels for mRNAs from two low pI alpha-amylase genes and from the single copy gene for aleurain, a thiol protease, using quantitative S1 nuclease protection assays. We found, in RNA from aleurone cells treated with gibberellic acid for 19-24 h, that the two low pI alpha-amylase mRNAs are each about five times more abundant than Amy6-4 or aleurain, which are, in turn, about 10 times more abundant than Amy46. These results indicate that as many as seven closely related high pI genes are needed to provide mRNA levels approaching those from the two low pI genes. We speculate that the substantially lower level of expression of Amy46 may be related to its divergent sequence upstream from the promoter.