Association of NAD(P)H:quinone oxidoreductase (NQO1) null with numbers of basal cell carcinomas: use of a multivariate model to rank the relative importance of this polymorphism and those at other relevant loci.

Glutathione S-transferase GSTM1 B and GSTT1 null, and cytochrome P450 CYP2D6 EM have been associated with cutaneous basal cell carcinoma (BCC) numbers, although their quantitative effects show that predisposition to many BCC is determined by an unknown number of further loci. We speculate that other loci that determine response to oxidative stress, such as NAD(H):quinone oxidoreductase (NQO1) are candidates. Accordingly, we assessed the association between NQO1 null and BCC numbers primarily to rank NQO1 null in a model that included genotypes already associated with BCC numbers. We found that only 14 out of 457 cases (3.1%) were NQO1 null. This frequency did not increase in cases with characteristics linked with BCC numbers including gender, skin type, a truncal lesion or more than one new BCC at any presentation (MPP). However, the mean number of BCC in NQO1*0 homozygotes was greater than in wild-type allele homozygotes and heterozygotes, although the difference was not quite significant (P = 0.06). These data reflect the link between NQO1 null and BCC numbers in the 42 MPP cases rather than the whole case group. We identified an interaction between NQO1 null and GSTT1 null that was associated with more BCC (P = 0.04), although only four cases had this combination. The relative influence of NQO1 null was studied in a multivariate model that included: (i) 241 patients in whom GSTM1 B, GSTT1 null and CYP2D6 EM genotype data were available, and (ii) 101 patients in whom these genotypes, as well as data on GSTM3, CYP1A1 and melanocyte-stimulating hormone receptor (MC1R) genotypes were available. NQO1 null (P = 0.001) and MC1R asp294/asp294 (P = 0.03) were linked with BCC numbers, and the association with CYP2D6 EM approached significance (P = 0.08). In a stepwise regression model only these genotypes were significantly associated with BCC numbers with NQO1 null being the most powerful predictor.

Identification of two activating elements in the proximal promoter region of the human glutathione transferase-A1 and -A2 genes.

Promoter regions derived from the human glutathione S-transferase (GST) alpha gene cluster located on chromosome 6p12 were studied: the identical proximal promoters of the GST A1 and GST A2 genes and a proximal promoter of a pseudogene of this class. The sequence of the pseudogene promoter differs in four single nucleotides at positions -86, -66, -41, and -13, and a noncritical TTT insertion at positions -71 to -69 from the GST A1/A2 promoter. Here, it was shown that the GST A1/A2 proximal promoters differed by a factor of 3.4 in their activity from the proximal pseudogene promoter. Therefore, the functional significance of single base exchanges was examined by introducing individual point mutations at the four positions within the proximal GST A1/A2 promoter. In functional tests in transiently transfected human hepatoblastoma HepG2 cells the base exchange at position -13 showed no effect, whereas mutations at position -41 or -86 diminished the promoter activity to a level comparable to the pseudogene promoter. Promoter fragments of both genes spanning over these four sites were analyzed in a heterologous promoter context for their functionality in HepG2 cells. Moreover, gel shift experiments showed specific binding of nuclear proteins to these promoter fragments. The results show that in the proximal GST A1/A2 promoter the sites at position -41 or -86 are essential for the binding of activating transcription factor complexes.

Iron status, menarche, and calcium supplementation in adolescent girls.

The effects of growth, menstrual status, and calcium supplementation on iron status were studied over 4 y in 354 girls in pubertal stage 2 who were premenarcheal at baseline (x+/-SD age: 10.8+/-0.8 y). Girls were randomly assigned to placebo or treatment with 1000 mg Ca/d as calcium citrate malate. Anthropometric characteristics, bone mass, and nutritional status were measured biannually; ferritin was measured annually; and red blood cell indexes were determined at 4 y. The simultaneous effects of iron intake and menstrual status on serum ferritin, after change in lean body mass (LBM) was controlled for, were evaluated in subjects in the upper and lower quartiles of cumulative iron intake. The average maximal accumulation of LBM (386 g/mo; 95% CI: 372, 399) occurred 0.5 y before the onset of menarche. Change in LBM was a significant predictor of serum ferritin (P < 0.0001), with a negative influence on iron status (t ratio=-4.12). The 2 fitted mathematical models representing ferritin concentrations of subjects in the upper and lower quartiles of cumulative iron intake were significantly different (P < 0.018). The regression line of the ferritin concentration in menstruating girls with high iron intakes had a less negative slope than the line fit to serum ferritin concentrations in girls with low iron intakes (NS). Serum ferritin concentrations at 0, 1, 2, 3, and 4 y were not significantly different between groups. In addition, there was no significant difference between groups in any of the red blood cell indexes. In summary, growth spurt and menstrual status had adverse effects on iron stores in adolescent girls with low iron intakes (<9 mg/d), whereas long-term supplementation with calcium (total intake: approximately 1500 mg/d) did not affect iron status.

Evidence for a posttranscriptional effect of retinoic acid on connexin43 gene expression via the 3'-untranslated region.

All-trans retinoic acid (10(-7) M) induces cell-cell communication and the expression of the gap junction protein connexin43 in mouse F9 teratocarcinoma cells. Previous experiments revealed an increase of mRNA but no change in the transcription of connexin43, suggesting a posttranscriptional mechanism responsible for the regulation of connexin43 gene expression. In transient transfection experiments using an expression vector containing the 3'-untranslated region of the connexin43 gene downstream of the luciferase coding sequence driven by the connexin43 promoter we show here that retinoic acid enhances luciferase activity via the connexin43 3'-untranslated region due to altered stability of the mRNA. Thus, retinoic acid is able to influence connexin43 gene expression at the level of mRNA stability via elements located in the 3'-untranslated region.

Analysis of connexin43 gene expression induced by retinoic acid in F9 teratocarcinoma cells.

All-trans retinoic acid (10(-7) M) induces cell-cell communication and expression of the gap junction protein connexin43 in mouse F9 teratocarcinoma cells. Northern blot analysis revealed an increase of connexin43 mRNA after treatment with retinoic acid, accompanied by an increase of the mRNA of collagen IV, a differentiation marker. To address the question at what level gene expression is enhanced by retinoic acid, nuclear run-on experiments were carried out. There was no detectable change in the level of newly transcribed connexin43 mRNA. Therefore, we postulate a post-transcriptional mechanism responsible for the regulation of connexin43 mRNA levels by retinoic acid.

Induction of gap junctional intercellular communication by vitamin D in human skin fibroblasts is dependent on the nuclear Induction of gap junctional intercellular communication by vitamin D in human skin fibroblasts is dependent on the nuclear vitamin D receptor.

The physiologically active metabolite of vitamin D, 1alpha,25-dihydroxyvitamin D3 (calcitriol), induces gap junctional intercellular communication in human skin fibroblasts 161BR at a concentration of 10(-7) M. In human skin fibroblasts, FIB5, devoid of a functional nuclear vitamin D receptor (VDR), there is no effect on gap junctional intercellular communication. Parallel to the increase in cell-cell communication, we observed a VDR-dependent increase in connexin43 protein and connexin43 mRNA levels. These results suggest that 1alpha,25-dihydroxyvitamin D3 affects gap junctional intercellular communication at the level of transcription or of mRNA stability via the nuclear VDR.

Estrogen-inducible derivatives of hepatocyte nuclear factor-4, hepatocyte nuclear factor-3 and liver factor B1 are differently affected by pure and partial antiestrogens.

The tissue-specific transcription factors of the hepatocyte nuclear factor-4 (HNF4), hepatocyte nuclear factor-3 (HNF3), and liver factor B1 (LFB1) families are thought to play a role in the development of internal organs and in the tissue-specific expression of many distinct genes. We have now constructed derivatives of these proteins by introducing the hormone-binding domain of the estrogen receptor and show that in transient transfections these chimeric proteins act as estrogen-inducible transcription factors with the DNA sequence specificity of the original factors. These chimeric transcription factors are differently affected by the partial estrogen antagonist 4-hydroxytamoxifen and the pure antiestrogen N-n-butyl-11-(3,17-dihydroxy-estra-1,3,5(10)-trien- 7 alpha-yl)N-methyl-undecamide (ICI 164384); 4-hydroxytamoxifen activates, at least partially, all the chimeric factors and the estrogen receptor, while ICI 164384 surprisingly activates the transcription factors derived from HNF3 and LFB1 and inhibits only the estrogen receptor and the HNF4 derivative. Together with the DNA-sequence-binding specificity, the different response to estrogen and anti-estrogens makes our estrogen receptor fusion proteins useful tools for the investigation of the roles of HNF4, HNF3 and LFB1 in gene expression, differentiation and developmental processes.

Lowered amounts of the tissue-specific transcription factor LFB1 (HNF1) correlate with decreased levels of glutathione S-transferase alpha messenger RNA in human renal cell carcinoma.

Human renal cell carcinoma is characterized by the loss of differentiation markers such as glutathione S-transferase alpha (GST-alpha). In this paper we show that the promoter of a GST-alpha gene contains a functional binding site for the cell-specific transcription factor LFB1 (HNF1). To investigate the potential role of LFB1 in the down-regulation of GST-alpha expression, we have compared the amount and the binding activity of the LFB1 protein between normal kidney and tumor tissue. By Western analysis and gel retardation assay using a monoclonal antibody specific for LFB1 we show that in 11 of 14 carcinomas the amount of LFB1 is clearly reduced compared to the corresponding normal tissue and that in all 14 renal carcinomas LFB1 binding activity is diminished. As in the same samples the abundance of GST-alpha mRNA is lower than in the normal tissue, we postulate that the loss of LFB1 binding activity might be responsible for the decreased expression of the GST-alpha gene in renal cell carcinoma.

Advanced applications of revascularized free jejunal flaps for difficult wounds of the head and neck.

The rationale, technique, and an example of full utilization of the jejunomesenteric free flap have been described as a means of reconstructing complex wounds of the head and neck. Not only jejunum, but also well-vascularized mesentery will protect vascular structures and intestinal anastomoses and, in addition, accept a skin graft. No additional muscular or other flaps are necessary to achieve these ends. Finally, no additional donor-site morbidity is incurred by harvesting the supplementary mesentery.

The incidence of occult metastases for cancer of the oral tongue and floor of the mouth: treatment rationale.

One hundred thirty-six surgical cases of squamous cell carcinoma of the oral tongue and floor of the mouth at the Emory University Hospitals were reviewed for the incidence of occult metastases. Thirty-five percent of the T1 T2 lesions of the anterior tongue had occult metastases. The figure was 31.5% for similarly staged lesions of the floor of the mouth. The presence of regional metastases resulted in a 2-year determinate survival rate of 37% and 32% for patients with oral tongue and floor of the mouth lesions, respectively. The poor prognosis in the study for delayed cervical metastases and the high incidence of occult cervical metastases have led the authors to propose a more aggressive therapy for the clinically negative necks in these two sites of squamous cell carcinoma of the oral cavity.

Complications of parotidectomy.

Parotidectomy, whether subtotal or total, is a surgical procedure associated with certain possible complications--namely, facial nerve injury, hemorrhage, infection, salivary fistula, seroma, keloid formation, greater auricular nerve anesthesia, gustatory sweating, and recurrent tumor. We review these complications to help the surgeon with preoperative patient counseling, as well as postoperative reassurance, and discuss those that are amenable to further treatment, either medical or surgical or both.

Facial nerve in recurrent benign pleomorphic adenoma.

Improvements in the treatment of benign and malignant tumors in the parotid gland have substantially reduced the incidence of recurrence. This has come about primarily be the abandonment of the enucleation techniques and the development of lateral lobectomy operation. The recurrence rate for benign mixed tumor in the parotid gland is variously reported in the ranges of 0.5% to 10%. Because the benign mixed tumor comprises approximately 65% of the tumors in this gland, this complication assumes an important and specific role. A review of this problem establishes the principles of management, extending from simple reexcision through total parotidectomy with preservation of the facial nerve, and radical parotidectomy with resection of the facial nerve and immediate nerve grafting.

Carcinoma of Stensen's duct.

The authors present 2 cases of carcinoma primary in Stensen's duct, one a mucoepidermoid carcinoma and the other an adenoid cystic carcinoma. This is an unusual site for a primary carcinoma and these are apparently the thirteenth and fourteenth cases to be reported in the English literature. The authors review the diagnosis and treatment for primary carcinoma of Stensen's duct.

Dermal-fat-fascia grafts.

Free dermal-fat-fascia grafts are used for subdermal augmentation in soft tissue or bony deficiencies resulting from surgical extirpation of cancer, congenitally arrested development, and trauma. The most important determinant for graft survival is the health of the recipient area and the volume of the graft. At least 70% resorption of these large grafts must be anticipated. Imitial overcorrection has some justification but may be self-defeating. Calcification of dermal-fat-fascia grafts, common in other areas of the body, does not appear to be a problem in the head and neck region. When possible, other types of augmentation procedures should be considered.