One year of surgical mask testing at the University of Bologna labs: Lessons learned from data analysis

The outbreak of SARS-CoV-2 pandemic highlighted the worldwide lack of surgical masks and personal protective equipment, which represent the main defense available against respiratory diseases as COVID-19. At the time, masks shortage was dramatic in Italy, the first European country seriously hit by the pandemic: aiming to address the emergency and to support the Italian industrial reconversion to the production of surgical masks, a multidisciplinary team of the University of Bologna organized a laboratory to test surgical masks according to European regulations. The group, driven by the expertise of chemical engineers, microbiologists, and occupational physicians, set-up the test lines to perform all the functional tests required. The laboratory started its activity on late March 2020, and as of the end of December of the same year 435 surgical mask prototypes were tested, with only 42 masks compliant to the European standard. From the analysis of the materials used, as well as of the production methods, it was found that a compliant surgical mask is most likely composed of three layers, a central meltblown filtration layer and two external spunbond comfort layers. An increase in the material thickness (grammage), or in the number of layers, does not improve the filtration efficiency, but leads to poor breathability, indicating that filtration depends not only on pure size exclusion, but other mechanisms are taking place (driven by electrostatic charge). The study critically reviewed the European standard procedures, identifying the weak aspects; among the others, the control of aerosol droplet size during the bacterial filtration test results to be crucial, since it can change the classification of a mask when its performance lies near to the limiting values of 95 or 98%.

Genome-wide paternal uniparental disomy as a cause of Beckwith-Wiedemann syndrome associated with recurrent virilizing adrenocortical tumors

Beckwith-Wiedemann syndrome (BWS) is an overgrowth syndrome characterized by fetal macrosomia, macroglossia, and abdominal wall defects. BWS patients are at risk to develop Wilms tumor, neuroblastoma, hepatoblastoma, and adrenal tumors. A young woman with BWS features, but with inconclusive genetic evidence for the disease, came to clinical observation for signs of virilization at the age of 16 years. An adrenocortical tumor was diagnosed and surgically resected. The tumor underwent 2 local relapses that were also surgically treated. The patient was also operated to remove a breast fibroadenoma. SNP arrays were used to analyze chromosome abnormalities in normal and tumor samples from the patient and her parents. The patient presented genome-wide mosaic paternal uniparental disomy (patUPD) both in the adrenocortical and the breast tumors, with different degrees of loss of heterozygosity (LOH). The more recent relapses of the adrenocortical tumor showed a loss of part of chromosome 17p that was absent in the first tumor. Analysis of a skin biopsy sample also showed mosaic patUPD with partial LOH, while no LOH was detected in leukocyte DNA. This case shows that virilizing adrenocortical tumors may be a clinical feature of patients with BWS. The SNP array technology is useful to diagnose genome-wide patUPD mosaicism in BWS patients with an inconclusive molecular diagnosis and underlines the tumorigenic potential of the absence of the maternal genome combined with an excess of the paternal genome.

Genomic analysis of sexual dimorphism of gene expression in the mouse adrenal gland

A relevant gender difference exists in adrenal physiology and propensity to disease. In mice, a remarkable sexual dimorphism is present in several components of the hypothalamic-pituitary-adrenal axis, with females displaying higher adrenal weight, plasma ACTH, corticosterone, and aldosterone levels than males. The molecular bases of this sexual dimorphism are little known. We have compared global gene expression profiles in males vs. female mouse adrenal glands and also studied the effect that testosterone treatment and castration have on adrenal gene expression in female vs. male mice, respectively. Our study evidenced a set of 71 genes that are coordinately modulated according to sex and hormonal treatments and represent the core sexually dimorphic expression program in the mouse adrenal gland. Moreover, we show that some genes involved in steroid metabolism have a remarkable sexual dimorphic expression and identify new potential markers for the adrenal X-zone, a transitory cellular layer in the inner adrenal cortex, which spontaneously regresses at puberty in males and during the first pregnancy in females and has an uncertain physiological role. Finally, sexually dimorphic expression of the transcriptional regulators Nr5a1 and Nr0b1 may explain at least in part the differences in adrenal steroidogenesis between sexes.

Regulation of human MC2-R gene expression by CREB, CREM, and ICER in the adrenocortical cell line Y1

The MC2-Receptor (melanocortin 2 receptor, MC2-R) is a Gs-protein coupled receptor that is upregulated by its own ligand ACTH and by forskolin. The mechanisms regulating MC2-R expression are still unclear. We therefore investigated the role of the stimulatory transcription factors CREB and CREM and the inhibitory factor ICER for regulation of human MC2-R expression. We cotransfected mouse adrenocortical Y1 cells with luciferase reporter gene vectors containing full length and deleted human MC2-R promoter constructs with expression plasmids for CREB, CREBS133A, CREMtau, CREMtauS117A, or ICER. Direct protein-DNA interaction was investigated by EMSA. Wild type CREB did not significantly affect promoter activity due to high endogenous CREB activity. However, CREBS133A decreased forskolin stimulated MC2-R promoter activity by 48+/-5% (mean+/-SEM) while unstimulated values remained unchanged. CREMtau moderately increased basal and forskolin stimulated luciferase activity in a dose-dependent manner (maximum effect 252+/-24% and 186+/-13% VS. control vector, respectively). While this effect required the full length promoter, cAMP stimulation was retained in shorter constructs. ICER reduced basal luciferase activity in Y1 cells by 17+/-28%, but completely abolished forskolin stimulation. Although 5'-deletion constructs mapped the minimum promoter region required for ICER effect to the shortest -64/+40 construct, direct protein DNA interaction in this promoter region could not be identified by EMSA. Moreover, mutation of the SF-1 binding sites, which retained ICER dependent inhibition, excluded SF-1 to be required for this effect. We conclude from these data that transcription factors of the CREB/CREM/ATF family have a moderate effect on human MC2-R promoter activity, but seem to play a minor role in transmitting stimulation of the cAMP pathway to increased MC2-R expression.

Increased serum osteoprotegerin values in long-lived subjects: different effects of inflammation and bone metabolism

AIM

To evaluate serum osteoprotegerin (OPG) concentrations in relation to age-dependent changes in serum markers of bone metabolism and systemic inflammation.

METHODS

Two-hundred and eighty-three healthy subjects were evaluated for plasma estimated creatinine clearance (Cr-clearance), C-reactive protein (CRP), bone alkaline phosphatase, C-telopeptides of type-1 collagen (CrossLaps), nuclear factor-kappaB ligand (RANKL) and OPG concentrations.

RESULTS

In adult subjects (82 cases aged between 27 and 64 years) serum OPG concentrations were significantly and independently correlated with RANKL and Cr-clearance (R(2): 0.29), but not with CRP and biochemical markers of bone metabolism. In old subjects who were between 65 and 84 years of age (52 cases) serum OPG concentrations were significantly higher as compared with the adult subjects and correlated independently and significantly with serum RANKL, Cr-clearance and CrossLaps values (R(2): 0.63). The highest OPG values were found in the long-lived subjects (149 cases with ages between 85 and 110 years) who also showed increased serum CrossLaps and CRP concentrations as compared with the younger subjects. However, in the long-lived subjects serum OPG concentrations were significantly and independently correlated with Cr-clearance and CRP (R(2): 0.45) but not with CrossLaps values.

CONCLUSIONS

These data would suggest that different factors might be responsible for the age-dependent enhancement of OPG production. Bone metabolism would seem to be the most important factor influencing serum OPG concentrations in old subjects under 85 years of age, whereas in long-lived subjects the circulating values of this cytokine seem to be mainly correlated with serum CRP which could be a marker of inflammation and cardiovascular risk.

Combinations of genetic changes in the human cAMP-responsive element modulator gene: a clue towards understanding some forms of male infertility?

The cAMP-responsive element modulator (CREM) gene plays a pivotal role in the mouse spermatogenesis, but its role in the human infertility has not been fully established. We performed a mutation screening in 13 Slovenian men with round spermatid arrest and in six controls. Eleven genetic changes have been identified in the human CREM gene, three novel single-nucleotide polymorphisms [within the promoters P1, P3 and intervening sequence 1 (IVS1)], one insertion (IVS2) and one non-sense mutation (exon gamma). Some infertile patients seem to accumulate potentially harmful genetic changes. We identified a patient with no CREM immunoreactive protein that was homozygous for the nucleotide changes in all promoters, IVS 1, 2, 6, and was heterozygous for the mutation in exon gamma. Interestingly, insertion in IVS2 (IVS2-58_55insT) results in a four-fold decrease in binding of nuclear proteins. Computer predictions suggested the presence of a potential novel CREM promoter, however, random amplification of cDNA ends from the human testis cDNA library was not successful in confirming a novel transcription start site of the CREM gene. Screening of a larger number of patients and controls is required to elucidate whether the observed combinations of genetic changes in the CREM gene can explain some forms of male infertility.

High serum osteoprotegerin levels in patients with hyperthyroidism: effect of medical treatment

This study was aimed at evaluating serum osteoprotegerin (OPG) concentrations in a cohort of patients with hyperthyroidism before and after methimazole (MMI) treatment. One hundred fourteen hyperthyroid patients [93 with Graves disease (GD) and 21 with toxic nodular goitre (TNG)] and 68 matched for sex and age healthy subjects were evaluated for serum free-thyroxine (FT4), free-triiodiothyronine (FT3), thyrotropin (TSH), TSH receptor antibodies (TRAb), bone alkaline phosphatase (BALP), C-telopeptides of type-1 collagen (CrossLaps), OPG levels, and bone mineral density (BMD). In hyperthyroid patients, the biochemical evaluations were performed before and after 6 and 12 months of MMI treatment, whereas BMD was measured at baseline and after 12 months of treatment. Hyperthyroidism was more severe in GD than TNG patients. Serum OPG levels were found to be significantly higher in hyperthyroid patients than in the healthy subjects (4.3 pmol/l, range: 1.6-12.0, vs. 2.2 pmol/l, range: 1.4-6.0; P < 0.001), the values being higher in GD patients than TNG. A significant correlation between serum OPG levels and age was found in the healthy subjects (r: 0.48; P < 0.001) but not in hyperthyroid patients (r: -0.03; P = 0.8). In the healthy subjects, serum OPG levels were also positively correlated with both serum FT4 (r: 0.23; P = 0.03) and FT3 (r: 0.24; P = 0.04) levels. In hyperthyroid patients, however, serum OPG was still correlated with FT3 levels (r: 0.38; P < 0.001), whereas the correlation with serum FT4 was lost (r: 0.19; P = 0.06). In hyperthyroid patients, but not in the healthy subjects, serum OPG levels were correlated positively with CrossLaps (r: 0.20; P = 0.03) and negatively with BALP (r: -0.24; P = 0.01) and BMD (r: -0.33; P = 0.01). After 6 months of MMI treatment, serum OPG concentrations decreased significantly in TNG patients (from 3.5 pmol/l, range: 1.6-8.0, to 2.3 pmol/l, range: 1.0-4.3; P < 0.001), whereas a not significant change in OPG levels occurred in GD patients (from 4.8 pmol/l, range: 1.8-12.0, to 4.2 pmol/l, range: 1.0-14.0; P = 0.7). At Month 12 of treatment, serum OPG concentrations were significantly lower than those measured at baseline in both TNG (2.5 pmol/l, range: 1.0-3.1, vs. 3.5 pmol/l, range: 1.6-8.0; P < 0.001) and GD (2.1 pmol/l, range: 1.0-8.6, vs. 4.8 pmol/l, range: 1.8-12.0; P < 0.001). At this time, no significant differences in serum OPG, CrossLaps, and BALP values were found between patients and control subjects. At the end of follow-up, BMD was higher than those measured at baseline but still significantly lower than those measured in the control subjects. This study shows that hyperthyroid patients have serum OPG concentrations significantly higher in comparison with euthyroid subjects, in relation to thyroid hormone excess and high bone turnover. Medical treatment of hyperthyroidism normalizes serum OPG levels in temporal relationship with the normalization of bone metabolism markers, even in presence of persistent abnormal bone structure as determined by ultrasonography.

Transcriptional regulation of the mouse steroidogenic acute regulatory protein gene by the cAMP response-element binding protein and steroidogenic factor 1

Transcriptional induction by cAMP is mediated through the interaction of the cAMP response-element binding protein (CREB) with a cAMP response element (CRE) in the promoter of target genes. The steroidogenic acute regulatory (StAR) protein gene is regulated by cAMP-mediated signaling in steroidogenic cells even though its promoter lacks a consensus CRE. Previously, we have identified three highly conserved 5'-CRE half-sites within the -96/-67 bp region of the mouse StAR gene, and a member of the CREB family (CREB/CRE modulator (CREM)) was shown to be involved in its expression and regulation. Here we show that CREB and CREMtau (but not CREMalpha and CREMbeta) have qualitatively similar effects on StAR promoter activity in response to (Bu)(2)cAMP. Studies on the effects of the functional integrity of the CRE half-sites on CREB-dependent (Bu)(2)cAMP-mediated StAR gene transcription demonstrated the greater importance of the CRE2 site in comparison with the CRE1 and CRE3 sites. The CRE2 sequence was also found to bind specifically to recombinant CREB protein and nuclear extract from MA-10 mouse Leydig tumor cells. The cAMP and CREB/CREM responsive region (-151/-1 bp) of the mouse StAR promoter also contains three recognition motifs for steroidogenic factor 1 (SF-1). Electrophoretic mobility shift assays and reporter gene analyses demonstrated the involvement of different SF-1 elements in StAR gene expression with the order of importance being SF-1/3>SF-1/1>SF-1/2. Specific mutations that eliminated the binding sites of CRE and SF-1 elements, either alone or in combination, resulted in an attenuation of StAR promoter activity, indicating that CREB and SF-1 can regulate StAR gene transcription in a cooperative fashion. In addition, mammalian two-hybrid assays revealed a high affinity protein-protein interaction between CREB/CREMtau and SF-1 which appeared to be dependent upon CREB protein phosphorylation. These findings further demonstrate CREB's role in StAR gene transcription and also provide evidence that the combined action of CREB/CREMtau and SF-1 results in enhanced activation of the StAR promoter.

Serum and follicular fluid cytokines in polycystic ovary syndrome during stimulated cycles

OBJECTIVE

To investigate the serum and intrafollicular tumor necrosis factor-alpha and interleukin-6 concentrations in infertile women with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF).

METHODS

Thirty-one patients with PCOS undergoing IVF were studied. Thirty-nine normally ovulating women matched for age and body mass index and undergoing IVF for male infertility were the control group. Serum tumor necrosis factor-alpha, interleukin-6, and estradiol levels were assayed before recombinant follicle-stimulating hormone stimulation under gonadotropin-releasing hormone analogue suppression and 34-36 hours after human chorionic gonadotropin (hCG) administration at the time of the oocyte retrieval. Cytokine and estradiol concentrations were also evaluated in the follicular fluids obtained at the time of oocyte retrieval.

RESULTS

The patients with PCOS had higher serum and follicular fluid tumor necrosis factor-alpha and interleukin-6 concentrations (P <.001) and lower follicular fluid estradiol levels (P <.05) than control women. In both groups, the serum tumor necrosis factor-alpha, interleukin-6, and estradiol values increased significantly after hCG stimulation. In both groups, the follicular fluid cytokine concentrations were higher than those found in the serum. In the PCOS women the follicular fluid tumor necrosis factor-alpha values were significantly and inversely correlated to the follicular fluid estradiol values (rho = -0.79; P <.001); this correlation was not found in the control subjects.

CONCLUSION

In infertile women with PCOS, 1). serum and follicular fluid interleukin-6 and tumor necrosis factor-alpha values were higher than those found in control women, 2). the cytokine concentrations were higher in the follicular fluid than in the serum, and 3). the intrafollicular tumor necrosis factor-alpha concentrations were significantly and inversely correlated to the estradiol levels. These results suggest an involvement of the immune system in PCOS.

Eight parathyroid glands incidentally discovered during a surgical intervention for secondary hyperparathyroidism: an unusual clinical finding

Here we describe the uncommon case of a Caucasian male with secondary hyperparathyroidism due to 8 parathyroid glands discovered in the course of a surgical exploration. The patient (age 49 yr) with a 21-yr history of chronic renal failure came to our observation in June 1999 complaining of depression, muscle weakness, bone and joint pain, movement hindrance. The biochemical evaluation evidenced low-normal serum calcium, high phosphorus and PTH levels. The symptoms and the biochemical findings were suggestive for secondary hyperparathyroidism. The neck US revealed an increase of thyroid gland volume with diffuse hyperechogenity; two nodules of 20 and 25 mm as maximum diameter were found in the thyroid parenchyma, while 4 hypoechogenous nodules (maximum diameter ranging from 13.0 to 30.0 mm) with clean borders and anechogenous areas inside were evidenced in the rear side of the thyroid lobes. The parathyroid scan with 99mTc and 201 Tl demonstrated increased uptake bilaterally in the inferior side of the neck. The patient underwent a total parathyroidectomy with near total thyroidectomy in November 1999. Histological examination of surgical specimen evidenced 6 hyperplastic parathyroid glands in back side of the 2 lobes (3 on the right and 3 on the left), and the examination of the thyroid gland showed 2 hyperplastic parathyroids (5 mm and 15 mm maximum diameter) into the 2 nodules previously evidenced by US. The physiopathological and clinical and therapeutic implications of this observation are discussed.

Heat shock interferes with steroidogenesis by reducing transcription of the steroidogenic acute regulatory protein gene

A key regulatory point in fine tuning of steroidogenesis is the synthesis of steroidogenic acute regulatory protein, which transfers cholesterol into mitochondria. Heat shock and toxic insults reduce steroidogenic acute regulatory protein, severely compromising steroid synthesis. As the molecular mechanisms for this reduction remain elusive, we tested the hypothesis that heat shock directly interferes with transcription of the steroidogenic acute regulatory protein gene. We show that, in mouse MA-10 Leydig tumor cells, heat shock caused drastic declines in (Bu)(2)cAMP-induced progesterone accumulation and steroidogenic acute regulatory protein transcript abundance. A proximal steroidogenic acute regulatory protein promoter fragment (-85 to +39) is sufficient to direct both cAMP inducibility and heat shock inhibition. Nuclear extracts from MA-10 cells displayed binding to this proximal promoter fragment as a low mobility complex in gel shift experiments. This complex disappeared in nuclear extracts taken at 5 and 10 min after initiation of heat shock and reappeared in extracts taken at 2 and 8 h. Similar low- mobility complexes formed on oligonucleotides representing the overlapping subfragments of the minimal steroidogenic acute regulatory protein promoter fragment sensitive to the heat shock effect. Extracts from heat-shocked MA-10 cells displayed reduced complex formation to each of the subfragments. We conclude that heat shock reduces progesterone synthesis, steroidogenic acute regulatory protein mRNA abundance, and steroidogenic acute regulatory protein promoter activity and disrupts binding of nuclear proteins to the proximal region of the steroidogenic acute regulatory protein promoter. Together these observations provide strong evidence for a mechanism of transcriptional inhibition in the down-regulation of steroidogenic acute regulatory protein expression by heat shock.

SF-1 (steroidogenic factor-1), C/EBPbeta (CCAAT/enhancer binding protein), and ubiquitous transcription factors NF1 (nuclear factor 1) and Sp1 (selective promoter factor 1) are required for regulation of the mouse aldose reductase-like gene (AKR1B7) expression in adrenocortical cells

The MVDP (mouse vas deferens protein) gene encodes an aldose reductase-like protein (AKR1B7) that is responsible for detoxifying isocaproaldehyde generated by steroidogenesis. In adrenocortical cell cultures, hormonal regulation of MVDP gene occurs through the cAMP pathway. We show that in adrenals, the pituitary hormone ACTH regulates MVDP gene expression in a coordinate fashion with steroidogenic genes. Cell transfection and DNA-binding studies were used to investigate the molecular mechanisms underlying MVDP gene regulation in Y1 adrenocortical cells. Progressive deletions of upstream regulatory regions identified a -121/+41 fragment that was sufficient for basal and cAMP-mediated transcriptional activities. Gel shift assays showed that CTF1/nuclear factor 1 (NF1), CCAAT enhancer binding protein-ss (C/EBPss), and selective promoter factor 1 (Sp1) factors bound to cis-acting elements at positions -76, -61, and -52, respectively. We report that the cell-specific steroidogenic factor-1 (SF-1) interacts specifically with a novel regulatory element located in the downstream half-site of the proximal androgen response element (AREp) at position -102. Functional analysis of SF-1 and NF1 sites in the -121/+41 promoter showed that mutation of one of them decreases both constitutive and forskolin-stimulated promoter activity without affecting the fold induction (forskolin stimulated/basal). Individual mutations of C/EBP and Sp1 sites resulted in a loss of more than 50% of the cAMP-dependent induction. When both sites were mutated simultaneously, cAMP responsiveness was nearly abolished. Thus, in adrenocortical cells, both SF-1 and NF1 are required for high expression of the MVDP promoter while Sp1 and C/EBPss functionally interact in an additive manner to mediate cAMP-dependent regulation. Furthermore, we report that MVDP gene regulation is impaired in stably transfected Y1 clones expressing DAX-1. Taken together, our findings suggest that detoxifying enzymes of the aldose reductase family may constitute new potential targets for regulators of adrenal and gonadal differentiation and function, e.g. SF-1 and DAX-1.

Recombinant growth hormone (GH) therapy in GH-deficient adults: a long-term controlled study on daily versus thrice weekly injections

Currently, replacement recombinant GH (rGH) therapy in GH-deficient (GHD) adults is performed in daily injections. This modality of treatment is not complied with by the totality of GHD patients, who are supposed to receive life-long replacement. The aim of our study was to compare daily vs. thrice weekly (TIW) rGH injection effects on lipid profile, body composition, bone metabolism, and bone density in 34 GHD patients (13 women and 21 men; median age, 39 yr; range, 30-55 yr) randomly assigned to different therapeutic regimens. Group A included 18 patients receiving daily rGH injections, and group B included 16 patients receiving TIW injections of rGH. The starting dose of rGH was 10 microg/kg x day in both groups. Subsequently, the dose was adjusted to maintain serum insulin-like growth factor I (IGF-I) concentrations in the normal age-adjusted range. IGF-I levels were assessed before and after 1, 3, 6, and 12 months of rGH treatment, and lipid profile, body composition, bone metabolism, and bone density were evaluated before and after 6 and 12 months of treatment. Thirty-four healthy subjects served as controls. In the basal condition, lipid profile, body composition, bone metabolism, and bone density were significantly different in patients compared to controls. Conversely, patients included in groups A and B had similar serum IGF-I levels, lipid profile, body composition, bone metabolism, and bone density. After 3 months of rGH treatment, IGF-I levels were normalized in 15 of 18 patients (83.3%) in group A and in 7 of 16 patients (43.7%) in group B (chi2 = 4.21; P = 0.04). At this time point, serum IGF-I levels in patients in group A (202+/-57.5 microg/L) were significantly higher than those in patients in group B (155+/-45.1 microg/L; P = 0.001). After 6 months of therapy, serum IGF-I levels were normalized in all patients and were similar in both groups (223+/-35.2 vs. 212+/-41.4 microg/L, A vs. B, respectively). IGF-I levels remained normal until the 12-month follow-up. After 6 months of rGH replacement, total cholesterol, low density lipoprotein cholesterol, triglycerides, bioelectrical impedance, and body fat mass were significantly reduced, whereas high density lipoprotein cholesterol levels and lean body mass were significantly increased in both groups of patients, without any difference between them. No further change in lipid profile and body composition was observed after 12 months of treatment. Serum bone GLA protein and procollagen III levels were significantly increased after 6 months, and a downward trend was observed after 12 months of rGH replacement. However, a slight, but significant, increase in bone mineral density was observed in both groups only after 12 months (P = 0.0001). All patients in group B had good compliance to the TIW treatment, whereas 5 patients in group A had poor compliance to the treatment (chi2 = 3.2; P = 0.07). In conclusion, our randomized, prospective, and controlled study confirmed that rGH therapy with TIW injection regimen is effective in normalizing IGF-I levels and improving lipid profile, body composition, bone metabolism, and bone density. It also demonstrated that this efficacy is comparable to that observed in patients treated with daily rhGH therapy, with few side-effects and good compliance.

Mammalian bufadienolide is synthesized from cholesterol in the adrenal cortex by a pathway that Is independent of cholesterol side-chain cleavage

An increasing body of evidence suggests that an endogenous mammalian bufadienolide (BD) may be involved in the regulation of Na(+),K(+)-ATPase activity and the pathogenesis of arterial hypertension. We developed a purification scheme for marinobufagenin (MBG), an amphibian cardiotonic BD, and applied it to purify and characterize material in human plasma, culture medium conditioned by Y-1 adrenocortical cells, and rat adrenal tissue. MBG immunoreactivity purified from plasma and measured by ELISA showed important similarities (chromatography and antibody cross-reactivity) to material secreted into cell culture medium by Y-1 cells. This observation indicates that circulating mammalian BD may have an adrenocortical origin. Release of mammalian BD from adrenocortical cells grown in the absence of exogenous cholesterol was reduced by treatment of cultures with mevastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor. Supplementation of the serum and cholesterol-free cell culture medium with the LDL fraction of human plasma increased the production of MBG material in the presence of mevastatin, supporting its origin from cholesterol. We used Y-1 cell lines transfected with genes shown to inhibit steroidogenesis through cholesterol side-chain cleavage (Y-1/DAX and Y-1/RIAB) to investigate the dependence of MBG biosynthesis on side-chain cleavage. Our results indicate that the mammalian BD is synthesized in the adrenal cortex from cholesterol and shares important similarities with the amphibian BD MBG, that its biosynthesis is independent of transfer of cholesterol to the side-chain cleavage enzyme complex mediated by steroidogenic acute regulatory protein, and that neither cAMP nor protein kinase A appears to be a critical component of the pathway controlling its biosynthesis.

Orphan receptor DAX-1 is a shuttling RNA binding protein associated with polyribosomes via mRNA

The DAX-1 (NR0B1) gene encodes an unusual member of the nuclear hormone receptor superfamily which acts as a transcriptional repressor. Mutations in the human DAX-1 gene cause X-linked adrenal hypoplasia congenita (AHC) associated with hypogonadotropic hypogonadism (HHG). We have studied the intracellular localization of the DAX-1 protein in human adrenal cortex and mouse Leydig tumor cells and found it to be both nuclear and cytoplasmic. A significant proportion of DAX-1 is associated with polyribosomes and is found complexed with polyadenylated RNA. DAX-1 directly binds to RNA, two domains within the protein being responsible for cooperative binding activity and specificity. Mutations in DAX-1 found in AHC-HHG patients significantly impair RNA binding. These findings reveal that DAX-1 plays multiple regulatory roles at the transcriptional and posttranscriptional levels.

DAX-1 blocks steroid production at multiple levels

DAX-1 is an unusual member of the nuclear hormone receptor superfamily whose expression is mainly, but not uniquely, restricted to steroidogenic tissues. We have recently shown that DAX-1 can block the first and rate-limiting step in steroid biosynthesis by repressing StAR (steroidogenic acute regulatory protein) expression. Here we show that DAX-1 blocks steroid production at multiple levels in the Y-1 mouse adrenocortical tumor cell line. Expression of DAX-1 in Y-1 cells significantly impairs both basal and cAMP-stimulated steroid production, without affecting the functionality of the cAMP-responsive PKA pathway. Experiments using an hydroxylated cholesterol derivative show that biochemical steps in steroidogenesis subsequent to cholesterol delivery to mitochondria are also impaired in Y-1 cells expressing DAX-1. This is explained by the repression of P450scc and 3beta-HSD expression, in addition to StAR. DAX-1 expression in Y-1 cells results in the inhibition of the activity of the StAR, P450scc and 3beta-HSD promoters. An inappropriate steroidogenic block in the male fetus might have an important role in the pathogenesis of sex reversal syndromes caused by a duplication of the genomic region of the X chromosome containing the DAX-1 gene.

DAX-1 expression in human adrenocortical neoplasms: implications for steroidogenesis

The DAX-1 gene encodes an orphan nuclear hormone receptor essential for normal fetal development of the adrenal cortex. Recently, DAX-1 has been shown to act as a transcriptional repressor of steroidogenic acute regulatory protein gene expression (StAR), suppressing steroidogenesis. We, therefore, investigated the expression of DAX-1 in a variety of adrenocortical tumors and compared the results with StAR mRNA expression. We found low or absent DAX-1 expression in aldosterone-producing adenomas (n = 11: 35 +/- 11%; normal adrenals: 100 +/- 17%) and in aldosterone-producing adrenocortical carcinomas (n = 2: 24 and 36%). Cortisol-producing adenomas showed intermediate DAX-1 expression (n = 8; 92 +/- 16), as did 3 non-aldosterone-producing carcinomas (72, 132 and 132%). High DAX-1 expression was present in nonfunctional adenomas (n = 3; 160 +/- 17%). In contrast to DAX-1, StAR mRNA expression did not show significant variations between groups. We did not detect the expected negative correlation between DAX-1 and StAR in adrenocortical tumors. These data suggest that high DAX-1 expression in adrenocortical tumors is associated with a non-functional phenotype whereas low DAX-1 expression favors mineralocorticoid secretion. These effects on steroidogenesis are mediated by mechanisms other than repression of StAR gene expression. Our results indicate that DAX-1 may be one of the factors influencing the steroid biosynthesis of adrenocortical neoplasms.

A transcriptional silencing domain in DAX-1 whose mutation causes adrenal hypoplasia congenita

The DAX-1 gene encodes an unusual member of the nuclear hormone receptor superfamily. Mutations in the human DAX-1 gene cause X-linked adrenal hypoplasia congenita associated with hypogonadotropic hypogonadism. We have shown that DAX-1 binds to hairpin secondary structures and blocks steroidogenesis in adrenal cells via transcriptional repression of the steroidogenic acute regulatory protein (StAR) promoter. Here we have investigated the molecular mechanism of DAX-1-mediated repression. We show that the DAX-1 C terminus contains a potent transcriptional silencing activity, which can be transferred to a heterologous DNA-binding domain. Deletion analysis and modeling of DAX-1 structure identify two cooperating domains required for the silencing function, one located within helix H3 and the other within H12. The silencing function is cell- and promoter-specific. Strikingly, two point mutations (R267P and deltaV269) found in adrenal hypoplasia patients impair silencing. These findings suggest that transcriptional silencing by DAX-1 plays a critical role in the pathogenesis of adrenal hypoplasia congenita.

DNA binding and transcriptional repression by DAX-1 blocks steroidogenesis

Mutations in the DAX-1 gene are responsible for congenital X-linked adrenal hypoplasia, a disease that is associated with hypogonadotropic hypogonadism. DAX-1 expression is tissue-specific and is finely regulated throughout development, suggesting that it has a role in both adrenal and gonadal function. DAX-1 is an unusual member of the nuclear-receptor superfamily of transcription factors which contains no canonical zinc-finger or any other known DNA-binding motif. Binding sites for DAX-1 are found in the promoters of the dax-1 and StAR (for steroidogenic acute regulatory protein) genes. Here we show that DAX-1 binds DNA and acts as a powerful transcriptional repressor of StAR gene expression, leading to a drastic decrease in steroid production. We provide in vitro and in vivo evidence that DAX-1 binds to DNA hairpin structures. Our results establish DAX-1 as the first member of the nuclear receptor superfamily with novel DNA-binding features and reveal that it has regulatory properties critical to the understanding of its physiological functions.

Hormonal and developmental regulation of DAX-1 expression in Sertoli cells

Mutations in the human DAX-1 gene lead to X-linked adrenal hypoplasia congenita and hypogonadotropic hypogonadism. DAX-1 has been proposed to play a role in steroidogenesis because it is highly expressed in adrenocortical and testicular Leydig cells and because loss-of-function mutations lead to low serum levels of steroid hormones. Recent reports of DAX-1 expression in hypothalamus and pituitary, however, suggest additional functions for this protein. Here we demonstrate that DAX-1 is expressed in Sertoli cells of rat testis. This expression is regulated during spermatogenesis and peaks during the androgen-sensitive phase of the spermatogenic cycle. In addition, we show that DAX-1 expression in Sertoli cells is regulated developmentally. Maximum levels are present in the rat between postnatal days 20 and 30, during the first spermatogenic wave. Moreover, we show that activation of the cAMP-signaling pathway by the pituitary hormone FSH leads to a potent down-regulation of DAX-1 expression in cultured Sertoli cells. This down-regulation requires transcription and de novo protein synthesis. Taken together, these data indicate that DAX-1 expression in Sertoli cells may influence the development of spermatogenic cells in response to steroid and pituitary hormones.

Steroidogenic factor 1 and Dax-1 colocalize in multiple cell lineages: potential links in endocrine development

Mutations of the orphan nuclear receptors, steroidogenic factor 1 (SF-1) and DAX-1, cause complex endocrine phenotypes that include impaired adrenal development and hypogonadotrophic hypogonadism. These similar phenotypes suggest that SF-1 and DAX-1 act in the same pathway(s) of endocrine development. To explore this model, we now compare directly their sites of expression. In mouse embryos, SF-1 expression in the urogenital ridge and brain either preceded or coincided with Dax-1 expression, with coordinate expression thereafter in the adrenal cortex, testis, ovary, hypothalamus, and anterior pituitary. The striking colocalization of SF-1 and Dax-1 supports the model that they are intimately linked in a common pathway of endocrine development. The slightly earlier onset of SF-1 expression and its ability to bind specifically to a conserved sequence in the Dax-1 5'-flanking region suggested that SF-1 may activate Dax-1 expression. However, promoter activity of Dax-1 5'-flanking sequences did not require this potential SF-1-responsive element, and Dax-1 expression was unimpaired in knockout mice lacking SF-1, establishing that SF-1 is not required for Dax-1 gene expression in these settings. Although the precise mechanisms remain to be established and may be multifactorial, our results strongly suggest that these two orphan nuclear receptors interact in a common pathway of endocrine development.

DNA ploidy analysis of squamous cell carcinomas of the oral and maxillofacial region: clinical and pathologic correlations

DNA ploidy was investigated in 61 specimens obtained from 25 patients with squamous carcinoma of the oral and maxillofacial region. Biopsy specimens of normal tissue surrounding the tumor were also obtained in six patients. Single-cell suspensions for flow cytometric analysis were prepared. The DNA ploidy and histogram were calculated and compared with the histologic grade, presence of lymph node metastases, and course of the disease. The ploidy of the main stemline was peridiploid in 17 carcinomas, hyperdiploid in three, and aneuploid in five. Histologic grade but not nodal involvement was associated with the ploidy of the main stemline. Of 15 multisampled carcinomas 13 showed constant DNA ploidy and histogram classification. In the other two major changes in DNA ploidy (from peridiploid to hyperdiploid in the first and from peridiploid to aneuploid in the second) were found. Survival information was available for 24 patients. Ploidy values higher or lower than 2.5 c were strongly predictive of both overall (p < 0.001) and relapse-free survival (p < 0.001). The lymph node status proved a powerful prognostic indicator (p = 0.014) but was not related to the relapse-free time of survival. Multiparametric evaluation of survival revealed an independent role of both DNA ploidy and nodal involvement in the prognosis of squamous carcinoma of the oral and maxillofacial region.

CREM: a master-switch in the transcriptional response to cAMP

The CREM gene encodes both repressors and activators of cAMP-dependent transcription in a tissue and developmentally regulated manner. In addition, multiple and cooperative phosphorylation events regulate the function of the CREM proteins. CREM plays a key physiological and developmental role within the hypothalamic-pituitary axis. There is a functional switch in CREM expression during the development of male germ cells which is directed by the pituitary hormone FSH. The CREM protein in germ cells is a powerful activator which appears to function as a master-switch in the regulation of postmeiotic genes. CREM is inducible by activation of the cAMP signalling pathway with the kinetics of an early response gene. The induction is transient, cell-specific, does not involve increased transcript stability and does not require protein synthesis. The subsequent decline in CREM expression requires de novo protein synthesis. The induced transcript encodes ICER and is generated from an alternative, intronic promoter. ICER functions as a powerful repressor of cAMP-induced transcription, and represses the activity of its own promoter, thus constituting a negative autoregulatory loop.

The nuclear response to cAMP: role of transcription factor CREM

In eukaryotes, transcriptional regulation upon stimulation of the adenylate cyclase signalling pathway is mediated by a family of cAMP-responsive nuclear factors. This family consists of a large number of members which may act as activators or repressors. These factors contain the basic domain/leucine zipper motifs and bind as dimers to cAMP-response elements (CRE). The function of CRE-binding proteins is modulated by phosphorylation by several kinases. The ICER (inducible cAMP early repressor) protein is the only inducible member of this family. The induction of this powerful repressor is likely to be important for the transient nature of cAMP-induced gene expression. CRE-binding proteins have been found to play an important role in the physiology of the pituitary gland, in regulating spermatogenesis, in the response to circadian rhythms and in the molecular basis of memory.

Block of T lymphocyte differentiation by activation of the cAMP-dependent signal transduction pathway

Differentiation of T lymphocytes is a complex and finely tuned process. Here we show that treatment of mouse fetal thymus organ cultures with agents activating the cAMP-dependent signalling pathway results in the block of thymocyte differentiation. This is due to severe impairment of maturation beyond the CD4-/CD8- stage. In addition, rearrangements at the TCR alpha gene locus, but not at the TCR beta locus, are completely inhibited. The cAMP effect is reversible and is restricted to TCR alpha beta+ cells. cAMP acts both by triggering apoptosis and by inducing cell-cycle block in thymocytes. Thus, activation of the cAMP pathway provides a mechanism to modulate thymic function for hormones and ligands whose receptors are coupled to adenylate cyclase.

Thyroid-stimulating hormone (TSH)-directed induction of the CREM gene in the thyroid gland participates in the long-term desensitization of the TSH receptor

Thyroid gland function is regulated by the hypothalamic-pituitary axis via the secretion of TSH, according to environmental, developmental, and circadian stimuli. TSH modulates both the secretion of thyroid hormone and gland trophism through interaction with a specific guanine nucleotide-binding protein-coupled receptor (TSH receptor; TSH-R), which elicits the activation of the cAMP-dependent signaling pathway. After TSH stimulation, the levels of TSH-R RNA are known to decrease dramatically within a few hours. This phenomenon ultimately leads to homologous long-term desensitization of the TSH-R. Here we show that TSH drives the induction of the inducible cAMP early repressor (ICER) isoform of the cAMP response element (CRE) modulator gene both in rat thyroid gland and in the differentiated thyroid cell line FRTL-5. The kinetics of ICER protein induction mirrors the down-regulation of TSH-R mRNA. ICER binds to a CRE-like sequence in the TSH-R promoter and represses its expression. Thus, ICER induction by TSH in the thyroid gland represents a paradigm of the molecular mechanism by which pituitary hormones elicit homologous long-term desensitization.

An unusual member of the nuclear hormone receptor superfamily responsible for X-linked adrenal hypoplasia congenita

X-linked adrenal hypoplasia congenita is a developmental disorder of the human adrenal gland that results in profound hormonal deficiencies and is lethal if untreated. We have isolated the gene responsible for the disease, DAX-1, which is deleted or mutated in X-linked adrenal hypoplasia patients. DAX-1 encodes a new member of the nuclear hormone receptor superfamily displaying a novel DNA-binding domain. The DAX-1 product acts as a dominant negative regulator of transcription mediated by the retinoic acid receptor.

Synergism between gamma interferon and doxorubicin in a human MDR colon adenocarcinoma cell line

Recent interest in cancer therapy derives from the ability of interferons to synergistically increase the activity of chemotherapeutic agents. To understand the biological basis of this synergism we evaluated the effects of human recombinant IFN-gamma on the expression of the mdr1 gene and on the cellular growth of a human colon adenocarcinoma cell line (LoVo) and its MDR subline (LoVo/Dx) after coincubation with doxorubicin. Treatment with IFN-gamma showed unchanged levels of MDR1-glycoprotein, no perturbation on cell cycle distribution and a significant reduction of colony formation in both lines (P < 0.05) starting from 100 U/ml. A synergistic effect was observed in the LoVo/Dx cell line when doxorubicin was added after exposure to 0.1-10 U/ml of IFN-gamma. Our data indicate that the effects of IFN-gamma, independent from action on cell proliferation and from modulation of p-glycoprotein expression, are a cause of the synergistic activity between this lymphokine and conventional chemotherapeutic agents such as doxorubicin.

Flow cytometry and in vitro tritiated thymidine labeling in normal rectal mucosa of patients at high risk of colorectal cancer

OBJECTIVES

To compare two different methods to evaluate rectal epithelial cell proliferation as a biomarker of risk of developing colon cancer.

METHODS

Samples of normal rectal mucosa from 26 patients at increased risk for colorectal cancer (22 patients with adenoma, three with adenocarcinoma of the large bowel, and one with longstanding ulcerative colitis) were examined by means of in vitro labeling with tritiated thymidine and flow cytometry.

RESULTS

We found a significant correlation between thymidine-labeling index and the percentage of cells in S-phase, measured by flow cytometry both in formalin-fixed, paraffin-embedded specimens and in frozen specimens (respectively, r = 0.7647, p < 0.001, and r = 0.4503, p < 0.01). However, using flow cytometry, the percentage of cells in S-phase was significantly higher than the thymidine-labeling index in both fixed-embedded and frozen specimens (p < 0.01). Proliferative parameters were not higher in patients with colon carcinoma, and were not related to the degree of dysplasia, the number of adenomas, or familial occurrence of colorectal cancer. Two specimens taken from normal rectal mucosa of two patients with adenomas showed aneuploidy. No aneuploidy was found in normal rectal specimens of patients with adenocarcinoma.

CONCLUSIONS

These results show that the calculation of cells in S-phase with in vitro tritiated thymidine labeling or by flow cytometry produces different results. However, the significant correlation between corresponding parameters obtained with these techniques support the use of either method as "intermediate biomarkers" of colorectal cancer risk and prognosis.

Inducibility and negative autoregulation of CREM: an alternative promoter directs the expression of ICER, an early response repressor

cAMP-responsive element modulator (CREM) expression is tissue specific and developmentally regulated. Here we report that CREM is unique within the family of cAMP-responsive promoter element (CRE)-binding factors since it is inducible by activation of the cAMP signaling pathway. The kinetic of expression is characteristic of an early response gene. The induction is transient and cell specific, does not involve increased transcript stability, and does not require protein synthesis. Significantly, the subsequent decline in CREM expression requires de novo protein synthesis. The induced transcript encodes a novel repressor, inducible cAMP early repressor (ICER), and is generated from an alternative intronic promoter. A cluster of four CREs in this promoter directs cAMP inducibility. ICER binds to these elements and thereby represses the activity of its own promoter, thus constituting a negative autoregulatory loop.

Decreased adhesion to endothelial cells and matrix proteins of H-2Kb gene transfected tumour cells

Transfection of murine metastatic B78H1 cells (derived from B16 melanoma) with a syngeneic H-2Kb gene was used to study the effect of Major Histocompatibility Complex (MHC) gene products on tumour cell adhesion to endothelial cells and matrix proteins and the involvement in the metastatic process. H-2Kb-expressing transfectants showed a reduced adhesion to endothelial surfaces of different origin (four murine endotheliomas and human umbilical vein endothelial cells) when compared to parental B78H1 cells and to controls transfected with pSV2neo alone. On the average a 50-70% reduction in adhesion to endothelial cells was observed among H-2Kb transfectants. H-2Kb transfectants had a reduced expression of the alpha 4 integrin subunit, moreover the adhesion of Neo-transfected clones to endothelial cells was reduced to the levels of H-2Kb transfectants by antibodies directed against the beta 1 subunit and the endothelial VCAM-1 molecule, thus suggesting an impairment of the VLA-4/VCAM-1 interaction in H-2Kb transfectants. Adhesion to extracellular matrix components was also strongly decreased: in general the adhesion of H-2Kb cells showed a 50-75% inhibition with respect to Neo or parental controls. The highest difference was observed in adhesion to vitronectin and laminin, the lowest in adhesion to fibronectin. Reduction in adhesive properties of H-2Kb-expressing transfectants could be involved in the reduced metastatic ability, evaluated by means of intravenous injection of cells: H-2Kb transfectants yielded less than ten lung colonies, while all controls produced more than 100. Our data indicate that expression of a single class I MHC gene can significantly alter the metastatic phenotype of MHC-negative tumour cells and this could be related to a general alteration of tumour cell adhesive interactions.

In situ hybridization in suspension and flow cytometry as a tool for the study of gene expression

We describe a method to detect mRNA expression using in situ hybridization in suspension and flow cytometry. Our model was glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene expression in the leukemic cell line K562. A GAPDH cDNA probe was labeled with digoxigenin-11-dUTP and detected using an FITC-labeled anti-digoxigenin antiserum. We obtained good resolution in specific signals against background (GAPDH signal/control plasmid signal ratio +/- SE 3.5 +/- 0.9). The technique was optimized taking into account several hybridization variables, like fixation, hybridization time, effect of blocking agents, and stringency wash variations. This method also allowed us to quantitate the GAPDH RNA copy number/cell using a fluorescence standard; we obtained a figure of about 1200 copies/cell, which is in good agreement with the dot blot hybridization assay result. Flow cytometric analysis of in situ hybridization represents an original method to study gene expression. This technique has the potential to develop into a multiparametric tool for cell biology studies, examining specific mRNA production together with DNA content or membrane molecules expression, and offering the possibility to purify by sorting a cell population expressing a specific mRNA.

Ly-6A/E gene is widely expressed among transformed nonhematopoietic cells. Autocrine modulation by interferon

Expression of the Ly-6A/E gene by transformed cells was investigated in 14 cell cultures of C57BL/6 and BALB/c mouse origin derived from spontaneous or chemically-induced non-hematopoietic tumours and from cells transformed by SV40 virus. Histologic types included carcinomas, sarcomas and a melanoma. Thirteen out of 14 cell cultures expressed membrane Ly-6A/E antigens; only the B16-A melanoma was negative, but it expressed Ly-6A/E after incubation with IFN-gamma. The effect of in vitro permanence was studied on early (< 10) and late (> 20) passages of B16-A melanoma and MN/MCA1 fibrosarcoma. Late passage B16-A cells were Ly-6A/E-negative and refractory to induction of Ly-6A/E (but not of H-2 antigens) by IFN-alpha, IFN-beta, or IFN-gamma; MN/MCA1 maintained a high expression of Ly-6A/E, but no increase was induced by IFNs. It was found that both early and late in vitro passages of MN/MCA1 actively produced IFN-alpha/beta. The analysis of cells of fibroblastic origin revealed a significant correlation between IFN release in the culture medium and Ly-6A/E levels. Culture of fibrosarcoma cells in the presence of an anti-IFN-alpha/beta serum reduced Ly-6A/E expression, thus indicating the existence of an autocrine loop.

Control of H-2 expression in transformed nonhaemopoietic cells by autocrine interferon

The relationship between autocrine interferon (IFN) production and the expression of class I Major Histocompatibility Complex (MHC) membrane glycoproteins in vitro was investigated in a panel of murine transformed cells of nonhaemopoietic origin. The panel included 11 cell lines of H-2Kb haplotype derived from fibrosarcomas, carcinomas and melanoma, and from transformed fibroblasts. IFN activity was detected in the conditioned medium of nine cell lines; fibrosarcomas were among the high IFN producers, while the non-producers were a melanoma clone and a lung carcinoma cell line. A significant correlation was found between IFN production and the expression of H-2K/D glycoproteins, thus suggesting that long-term maintainment of MHC glycoprotein expression in vitro could be mediated by self produced IFN. Two IFN producer cell lines, MN/MCA1 and R80/17, were cultured in the presence of a blocking antiserum against IFN-alpha/beta: a significant decrease in H-2b expression was observed, thus indicating the existence of an autocrine IFN circuit. Taken together these findings suggest that release of IFN is a frequent event among transformed nonhaemopoietic cells, and that self-produced IFN contributes to the regulation of MHC antigen levels in solid tumours.

Serum markers of immune activation and liver allograft rejection

We monitored the immune response after liver transplantation in 20 patients by measuring the serum levels of soluble interleukin-2 receptor (sIL-2R), soluble CD8 (sCD8), serum amyloid-A protein (SAA), and tumor necrosis factor-alpha (TNF-alpha). In six patients data were available to extend the follow-up period to one year. In all patients mean sIL-2R levels increased in the first month after liver transplantation, and subsequently decreased to values similar to pre-OLT ones, while SAA mean levels rose in the first week after OLT only in patients with rejection. sCD8 levels did not significantly rise after OLT, and TNF-alpha was undetectable in most cases. During episodes of rejection, rejector patients had significantly higher levels of sIL-2R, sCD8, and SAA than stable (without complications) patients. Conversely, no significant difference between rejectors and patients with other complications existed for any of the markers studied. These results diminish the importance of these serum markers of immune activation as laboratory tools in the differential diagnosis of acute rejection from other complications. However, sIL-2R, SAA, and sCD8 levels correlated with the histological grade of rejection and therefore can be utilized to monitor patients with an established diagnosis of acute rejection.

Immune defects in families and patients with xeroderma pigmentosum and trichothiodystrophy

Xeroderma pigmentosum (XP) is a rare autosomal recessive disease characterized by photosensitivity, a high incidence of cancer in sun-exposed portions of the skin and a reduced capacity to repair the u.v.-induced DNA damage. One of the XP mutations (XP-D) has also been identified in patients affected by trichothiodystrophy (TTD), a rare autosomal recessive disease characterized by brittle hair, mental and physical retardation, peculiar face and ichthyosis. However, in these patients there is no evidence of increased skin tumour incidence. Since an impairment of cell-mediated immunity has been proposed as a co-factor in the cancer proneness of XP patients, we investigated the involvement of immune defect(s) in five XP patients, five TTD patients, their parents, and 24 TTD relatives. We evaluated the phenotype of circulating lymphocytes, natural killer (NK) cell lytic activity, target cell binding of NK cells at single cell level and the effect of interferons (IFN) alpha and beta on NK cell activity. The relative proportion of CD3+ and CD4+ circulating lymphocytes was reduced in XP but not in TTD patients. NK cell lytic activity was decreased in XP patients and their mothers, but their fathers showed normal lytic activity. NK activity varied among TTD families: four out of five patients and their relatives presented low NK cell activity, and one family was normal. In TTD family members, NK activity increased after incubation with IFN-alpha or IFN-beta, but never reached normal values. In contrast, in XP patients and their mothers, the defect was almost completely corrected after in vitro incubation with IFN-alpha or IFN-beta. Our study indicates impaired NK lytic activity in the majority of TTD and XP patients and that this defect is present also in members of their families. In addition, XP patients present a low number of circulating T cells. These multiple abnormalities, together with DNA repair defects, could be related to the increased cancer risk in XP patients.

Serum amyloid A protein concentration in bone marrow transplantation for beta thalassaemia

AIMS

To investigate whether serum amyloid A protein (SAA) and C-reactive protein (CRP) concentrations could be used in the management of beta thalassaemic patients undergoing bone marrow transplantation (BMT).

METHODS

Serum SAA and CRP concentrations were determined in paired samples from 66 patients with beta thalassaemia before and after BMT. Serum SAA concentrations were determined by an enzyme linked immunoassay (EIA); serum CRP concentrations were determined by a nephelometric assay.

RESULTS

Serum SAA concentrations before transplantation were significantly higher in the group that subsequently rejected the transplant than the group without complications. SAA concentrations increased after BMT in acute graft versus host disease (GvHD) and rejection. No significant increase in SAA or CRP was found in chronic GvHD. Increases in serum in SAA and CRP concentrations were not related to concomitant infection episodes.

CONCLUSIONS

The different acute phase response in acute GvHD and rejection compared with chronic GvHD suggests that different immunopathogenic mechanisms are responsible.