Prevalence of the Cys282Tyr and His63Asp HFE gene mutations in Spanish patients with hereditary hemochromatosis and in controls

The article outlines a nine-step process adopted at The University of Texas MD Anderson Cancer Center for handling patient requests for medically inappropriate interventions. The main step in the process is review by an Institutional Review Committee composed of the physician-in-chief, ethics committee members, and medical experts. The decision of the Review Committee is binding. The experience with this "futility" policy is discussed including a follow-up pilot project conducted by the Department of Gynaecologic Oncology that introduces a standardized advance care planning medical record progress note in which patient preferences about cardiopulmonary resuscitation, mechanical ventilation, and location of death are documented. The note is to be used at the beginning of non-curative therapy and is intended to help to avoid future requests for futile interventions.     

Cys2/His2 zinc-finger protein family of petunia: evolution and general mechanism of target-sequence recognition

In recent pediatric trials of acute myeloid leukemia (AML), children with Down syndrome (DS) have had significantly more megakaryoblastic leukemia and have experienced better outcome than other children. To further characterize AML in DS, Children's Cancer Group Studies 2861 and 2891 prospectively studied demography, biology, and response in AML and myelodysplastic syndrome (MDS) of children with and without DS. These studies evaluated timing of induction therapy and compared postremission chemotherapy with marrow transplantation in 1,206 children. One-hundred eighteen (9.8%) had DS, a fourfold increase in 20 years. DS patients were younger, had lower white blood cell and platelet counts, more antecedent MDS, acute megakaryoblastic leukemia or undifferentiated AML, and an under-representation of chromosomal translocations (P < .001 for each variable). Four-year event-free survival in DS was 69% versus 35% in others (P < .001). Intensively timed induction conferred significantly higher mortality in DS patients; bone marrow transplantation offered no advantage. Conventional induction followed by chemotherapy achieved an 88%, 4-year, disease-free survival in DS patients versus 42% in others (P < .001). Megakaryoblastic leukemia was unfavorable in others but prognostically neutral in DS. AML in DS is demographically and biologically distinct from AML in other children. It is singularly responsive to conventional chemotherapy and may warrant even less therapy. The increasing proportion of DS patients with AML most likely reflects changes in attitudes about entering DS patients on AML trials and possibly increasing ability to distinguish megakaryoblastic leukemia from lymphoid leukemia.     

Prevalence of the C282Y and H63D mutations in the HFE gene in patients with hereditary haemochromatosis and in control subjects from Northern Germany

Mutation analysis was performed for two HFE mutations (C282Y, H63D) in unrelated patients with hereditary haemochromatosis (n = 92), family members of patients (n = 34), and unrelated controls (n = 157) from Northern Germany, 87/92 patients (94.6%) revealed the C282Y mutation in homozygous form, five were heterozygous. No H63D mutation was found in 174 chromosomes of patients homozygous for C282Y, whereas four of the heterozygote patients also carried the H63D mutation. Among the control group, 9.6% were heterozygotes for C282Y. 2/157 subjects were homozygous, 37/157 were heterozygous for the H63D mutation, but showed no signs of iron overload.     

His1069Gln and six novel Wilson disease mutations: analysis of relevance for early diagnosis and phenotype

In the present study we examined 33 German and 10 Cuban unrelated Wilson disease (WND) index patients and their relatives. The common His1069Gln mutation accounted for 42% of all WND chromosomes in the German series and the haplotype C was found to be highly predictive for this mutation. Six WND gene mutations have not been described previously and involved a splice site at intron 18 (3903 + del1G), a termination codon in the copper-binding region of exon 2 (Cys271X), and missense mutations in transmembrane region 2 (Gly710Ala), in transmembrane region 3 (Tyr741Cys), in the DKTGT motif (Thr1031Ile) and in the ATP loop region (Gly1176Arg). In 15 German WND index patients and three sibs both WND mutations could be determined and a genotype-phenotype correlation was attempted. Patients homozygous for the His1069Gln mutation showed almost the complete range of clinical presentations, and thus in our study this mutation is not associated with a late, neurological presentation.     

Effects of two hypertrophic cardiomyopathy mutations in alpha-tropomyosin, Asp175Asn and Glu180Gly, on Ca2+ regulation of thin filament motility

The biological activity of the Alzheimer's disease amyloid beta protein may be related to modulation of membrane lipid peroxidation. The effect of amyloid beta protein fragment 25-35 [A beta(25-35)] on lipid peroxidation was examined in liposomes enriched with polyunsaturated fatty acids. The activity of A beta(25-35) was compared to that of A beta(25-35) with either a scrambled sequence [A beta(25-35)scram] or a peptide sequence in which methionine was replaced with leucine [A beta(25-35) met]. A beta(25-35) inhibited lipid peroxidation in a dose- and time-dependent manner. The antioxidant activity of A beta(25-35) was observed at concentrations as low as 10 nM. The relative antioxidant activities of the amyloid beta protein fragments were as follows: A beta(25-35) > A beta(25-35) met > A beta(25-35)scram. The two more potent peptides intercalated into the membrane hydrocarbon core, as determined by small-angle x-ray diffraction approaches. These findings indicate that the amphiphilic A beta(25-35) peptide inhibits lipid peroxidation at low concentrations as a result of physicochemical interactions with the membrane lipid bilayer.     

UKPDS 19: heterogeneity in NIDDM: separate contributions of IRS-1 and beta 3-adrenergic-receptor mutations to insulin resistance and obesity respectively with no evidence for glycogen synthase gene mutations. UK Prospective Diabetes Study

Insulin receptor substrate-1 (IRS-1), beta 3-adrenergic-receptor (beta 3-AR) and glycogen synthase (GS) genes are candidate genes for non-insulin-dependent diabetes mellitus (NIDDM), insulin resistance, dyslipidaemia and obesity. We studied white Caucasian subjects with NIDDM, 227 being randomly selected, 49 NIDDM within the top two percentiles of insulin resistance; 54 with dyslipidaemia in the top quintile of triglyceride/insulin and the bottom quintile of HDL, and 166 non-diabetic control subjects. We examined the association of the simple tandem repeat DNA polymorphisms (STRPs) near the IRS-1 and GS genes, and the prevalence of mutations at codons of IRS-1 513 and 972, beta 3-AR 64 and GS 464 using restriction fragment length polymorphism (RFLP). The STRP alleles in IRS-1 were significantly different between NIDDM and control subjects (p = 0.015). The IRS-1 972 mutation was significantly different between the four groups with increased prevalence in the insulin resistant and dyslipidaemia subjects (18 and 26% compared with 11% in control subjects; p < 0.0005). Those with or without IRS-1 mutations had similar clinical characteristics and impaired insulin sensitivity. beta 3-AR 64 mutation was not significantly different between the four groups but those with the mutation were more obese, with a test for linear association between number of alleles and degree of obesity in an analysis of variance showing a significant association (p = 0.029). The GS 464 mutation was not detected in any of the diabetic or control subjects and the population association study using GS STRP showed no difference in allelic frequencies between NIDDM patients and control subjects. A mutation in lipoprotein lipase at codon 291, associated in the general population with low HDL cholesterol, was not at increased prevalence in the NIDDM patients with dyslipidaemia. In conclusion, IRS-1 972 had an increased prevalence in subjects with insulin resistance, with or without dyslipidaemia. beta 3-AR 64 was associated with increased obesity but not with insulin resistance or dyslipidaemia. These separate contributions to different features of NIDDM are an example of the polygenic inheritance of this heterogeneous disorder.     

Breast cancer in patients treated for Hodgkin's disease: clinical and pathological analysis of 76 cases in 63 patients

In a retrospective multicentric analysis, 63 women treated between 1941 to 1988 for Hodgkin's disease (HD) subsequently developed 76 breast cancers (BC). The median age at diagnosis of HD was 26 years (range 7-67), and 22 women (35%) were 20 years old or less. Exclusive radiotherapy (RT) was used in 36 women (57%) and combined modalities with chemotherapy (CT) in 25 (39%). Breast cancer occurred after a median interval of 16 years (range 2-40) and the median age at diagnosis of the first BC was 42 years (range 25-73). TNM classification (UICC, 1978) showed 10 T0 (non-palpable lesions) (13%), 20 T1 (26%), 22 T2 (29%), 8 T3 (11%), 7 T4 (9%) and 9 Tx (12%), giving altogether a total of 76 tumours, including, respectively, 5 and 8 bilateral synchronous and metachronous lesions. Among the 68 tumours initially discovered, 53 ductal infiltrating, one lobular infiltrating and two medullary carcinomas were found. Moreover, two fibrosarcomas and 10 ductal carcinoma in situ (DCIS) were also found. Among 50 axillary dissections for invasive carcinomas, histological involvement was found in 31 cases (62%). 45 tumours were treated by mastectomy, without (n = 35) or with (n = 10) RT. 27 tumours had lumpectomy, without (n = 7) or with RT (n = 20). 2 others received RT only, and one only CT. 7 patients (11%) developed isolated local recurrence. 20 patients (32%) developed metastases and all died; 38 are in complete remission, whereas 5 died of intercurrent disease. The 5-year disease-specific survival rate by the Kaplan-Meier method was 61%. The 5-year disease-specific survival rate for pN0, pN1-3 and pN > or = 3 groups were 91%, 66% and 0%, respectively (P < 0.0001) and 100%, 88%, 64% and 23% for the T0, T1, T2 and T3T4 groups, respectively. These secondary BCs seem to be of two types: a large number of aggressive tumours with a very unfavourable prognosis (especially in the case of pN > 3 and/or T3T4); and many tumours with a 'slow development' such as DCIS and microinvasive lesions, especially in patients treated exclusively by RT. Moreover, a very unusual rate of bilateral tumours (21%) was observed. These secondary BC could be 'in field', in 'border of field' or 'out of field'. However, a complete analysis of doses delivered by supradiaphragmatic irradiation was often very difficult, due to large variations in several parameters. We conclude that young women and girls treated for HD should be carefully monitored by clinical examination, mammography and ultrasonography.     

Chondrosarcoma in Ollier''s disease. Apropos of 2 cases and review of the literature]

OBJECTIVE: To study the value of two outpatient urine tests with regard to the diagnosis and recurrence of bladder tumors. METHODS: Fifty patients with a history of superficial bladder cancer were evaluated with urinary NMP22 levels (cutoff level 10 U/ml), bladder wash karyometry (low versus intermediate and high risk) and cystoscopy. All patients were followed for 1 year. RESULTS: Diagnostic negative and positive predictive values (NPV and PPV) of the tests were, respectively: NMP22 91.2 and 56.3%, and karyometry 80 and 33.3%. Prognostic NPV and PPV with regard to a subsequent recurrence were, respectively: NMP22 77.8 and 27.3%, and karyometry 82.6 and 50%. CONCLUSION: The diagnostic value of NMP22 is good. Since the 3 false-negative results were in low-stage and low-grade lesions, this test could be used as a prescreening for cystoscopy. The NPV of these tests with regard to tumor recurrence is around 80%, but only karyometry has a significant PPV. Change in the follow-up policy on the basis of these tests remains difficult. In patients with neobladders NMP22 appears to be of little use, because of the high urinary NMP22 levels in the absence of malignancy.     

Digestive cancers and choroid metastasis. Diagnostic circumstances and prognostic value apropos of 2 cases]

We report two observations of malignant gastric and pancreatic tumors with choroid metastasis. Clinical course was rapidly and spontaneously unfavorable.     

Genetic polymorphism of drug metabolizing enzymes: new mutations in CYP2D6 and CYP2A6 genes in Japanese]

The postnatal development of serotonin (5HT)-immunoreactive axons was studied in the visual cortex of the cerebrum in both normal and microcephalic rats during early postnatal and young adult stages. Severe microcephaly in rat offspring was induced by prenatal exposure to methylazoxymethanol acetate (MAM), an anti-mitotic agent, on day 15 of gestation. From postnatal day 1 (PND 1) to PND 5, fine and short 5HT fibers were irregularly dispersed throughout the occipital cortex in both the control and MAM-treated rats (MAM-rats). A conspicuous aggregation of dot-like 5HT terminals was found in controls, but not in MAM-rats, in a shallow layer of the dorsomedial region of the occipital cortical plate. On PND 7, such an aggregation of 5HT terminals was found in both groups. The density of the aggregation increased up to PND 9, but then decreased gradually, finally becoming unrecognizable at around PND 15 in both groups. MAM-rats, however, always showed hyperaggregation of 5HT terminals when compared with controls on the same PND. The density of 5HT fibers gradually increased, and finally made up a network-like formation at PND 28 in both groups, its pattern was essentially identical to the abnormal distribution of 5HT fibers during the later stage. As a result, the network-like formation of 5HT fibers in the MAM-rats at PND 28 was markedly twisted and somewhat hyperdense. In Nissl-stained preparations from PND 9 to 15, the 5HT terminal aggregation in the control rats was precisely confined to the newly forming layer IV of the visual cortex. In the MAM-rats, on the other hand, the aggregation of 5HT terminals was not associated with a specific cortical layer because of a disarranged cytoarchitecture of the microcephaly.     

Soft tissue infections with S. Lugdunensis. Presentation of 2 cases and general review]

When perfusion pressure to the kidney falls, e.g., as a result of dehydration or mechanical hindrance to the renal arterial blood flow, the release of renin, hence angiotensin (Ang), surges. This feedback regulation is geared to preservation of renal hemodynamic environment by raising systemic blood pressure. We are aware that a surge of renin-angiotensin release also occurs when there is a mechanical hindrance to urine outflow. This phenomenon of ureteral pressure-sensitive activation of renin-angiotensin has been heretofore viewed as an error of nature. We have obtained evidence which challenges this traditional view when we examined strains of mutant mice which are completely devoid of either angiotensin type 1 (AT1) receptor gene (Agtr1-) or angiotensin type 2 (AT2) receptor gene (Agtr2-) as a result of genetic manipulation of these animals. These strains of mice display varying degrees of urinary tract obstruction. In Agtr2- mice obstructions develop during early kidney ontogenesis in ureto, and, in Agtr1- mice, during late ontogenesis ex utero. One may recall that, throughout its normal ontogenesis, the kidney is twice at risk for obstruction of urine outflow. Thus, in utero the ureter is transiently obliterated. This transient obliteration is believed to protect the kidney from the high pressure from the cloaca when urine is not yet formed. During this period, the ureter is surrounded by dense layers of undifferentiated mesenchymal cells. Subsequent expansive growth that the ureter must achieve, therefore, in concert with a timely disappearance of the surrounding mesenchymal cells. The study in Agtr2- embryos indicated that Ang, through the Agtr2 receptor, promotes disappearance of these mesenchymal cells, and that inactivation of this receptor results in congenital obstructive nephropathy. Our additional studies in human specimens indeed indicate that many infants with congenital anomalies of the kidney and urinary tract have a significant mutation within the AT2 gene. Once animals are born, the kidney comes to be of primary importance for preservation of body fluid homeostasis, and urinary output increases dramatically. The large volume of urine predisposes the kidney to obstructive nephropathy due to the high resistance offered to the urine by the downstream ureter. Normally, a special device develops within the urinary tract in a timely fashion, which enables the kidney to collect a bulk of urine, and then to expel it downward periodically without imposing positive pressure upon the renal parenchyma. This special device is the renal pelvis. In the studies on Agtr1 null mutant mice, we learned that Ang, through the AT1 receptor, promotes development of the pelvis shortly after birth, so that inactivation of this receptor in Agtr1- mice leads to absence of development of the pelvis, hence to obstructive nephropathy. Collectively, Agtr1 or Agtr2 null mutant mice suffer from urinary tract obstruction. Given that urinary tract obstruction per se is a potent stimulus for Ang generation, Ang is essential for the kidney to escape from obstructive injury.     

Haplotype analysis of two recurrent CDKN2A mutations in 10 melanoma families: evidence for common founders and independent mutations

Germ-line mutations in CDKN2A have been shown to predispose to cutaneous malignant melanoma. We have identified 2 new melanoma kindreds which carry a duplication of a 24bp repeat present in the 5' region of CDKN2A previously identified in melanoma families from Australia and the United States. This mutation has now been reported in 5 melanoma families from 3 continents: Europe, North America, and Australasia. The M53I mutation in exon 2 of CDKN2A has also been documented in 5 melanoma families from Australia and North America. The aim of this study was to determine whether the occurrence of the mutations in these families from geographically diverse populations represented mutation hotspots within CDKN2A or were due to common ancestors. Haplotypes of 11 microsatellite markers flanking CDKN2A were constructed in 5 families carrying the M53I mutation and 5 families carrying the 24bp duplication. There were some differences in the segregating haplotypes due primarily to recombinations and mutations within the short tandem-repeat markers; however, the data provide evidence to indicate that there were at least 3 independent 24bp duplication events and possibly only 1 original M53I mutation. This is the first study to date which indicates common founders in melanoma families from different continents.     

Characterization of benzo[a]pyrene-initiated mouse skin papillomas for Ha-ras mutations and protein kinase C levels

The frequency and spectrum of Ha-ras mutations in benzo[a]pyrene (B[a]P)-initiated/12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted CD-1 mouse skin papillomas were characterized by amplifying high molecular weight papilloma DNA using the polymerase chain reaction (PCR) followed by direct DNA sequencing. Analysis of 10 individual B[a]P-initiated early emergence papillomas indicated that 90% contained a Ha-ras mutation. Twenty percent of these papillomas contained a GGA-->GTA transversion in the 12th codon, 50% contained a GGC-->GTC transversion in the 13th codon and 20% contained a CAA-->CTA transversion in the 61st codon. A characteristic of 7,12-dimethylbenz[a]anthracene (DMBA)-initiated papillomas, which contain an A-->T mutation in the 61st codon of Ha-ras, is that they exhibit a constitutive decrease in both protein kinase C (PKC) activity and PKC alpha and beta 2 isozyme levels when compared to epidermis. In the present study we found that total PKC activity, as well as PKC alpha and beta 2 isoforms, were markedly decreased in B[a]P-initiated early emergence papillomas and that this decrease was also accompanied by an altered subcellular distribution of PKC activity. The particulate/cytosolic (P/C) ratio of PKC activity in the epidermis was 0.39, whereas the P/C ratio in the papillomas was 0.77. These results demonstrate that B[a]P-initiated/TPA-promoted papillomas exhibit a high incidence of specific ras mutations and that PKC levels are constitutively decreased in these papillomas, indicating that an activated ras gene is associated with and may contribute to the observed decrease in PKC levels.     

Direct synthesis of [DOTA-DPhe1]-octreotide and [DOTA-DPhe1,Tyr3]-octreotide (SMT487): two conjugates for systemic delivery of radiotherapeutical nuclides to somatostatin receptor positive tumors in man

Direct attachment of unprotected DOTA (1,4,7,10-tetraazacyclododecane-N',N",N"',N"-tetraacetic acid) to partially suitably protected octreotide or [Tyr3]-octreotide leads after deprotection to [DOTA-DPhe1]-octreotide (III) and [DOTA-DPhe1,Tyr3]-octreotide (IV). These DOTA-containing somatostatin analogs, when labeled with a radiotherapeutic nuclide, are useful as antitumor agents. The partially protected peptides are accessible via solid phase peptide synthesis (SPPS) followed by selective cleavage under mild acidic conditions from the resin.     

Synthetic lethality of yeast slt mutations with U2 small nuclear RNA mutations suggests functional interactions between U2 and U5 snRNPs that are important for both steps of pre-mRNA splicing

A genetic screen was devised to identify Saccharomyces cerevisiae splicing factors that are important for the function of the 5' end of U2 snRNA. Six slt (stands for synthetic lethality with U2) mutants were isolated on the basis of synthetic lethality with a U2 snRNA mutation that perturbs the U2-U6 snRNA helix II interaction. SLT11 encodes a new splicing factor and SLT22 encodes a new RNA-dependent ATPase RNA helicase (D. Xu, S. Nouraini, D. Field, S. J. Tang, and J. D. Friesen, Nature 381:709-713, 1996). The remaining four slt mutations are new alleles of previously identified splicing genes: slt15, previously identified as prp17 (slt15/prp17-100), slt16/smd3-1, slt17/slu7-100, and slt21/prp8-21. slt11-1 and slt22-1 are synthetically lethal with mutations in the 3' end of U6 snRNA, a region that affects U2-U6 snRNA helix II; however, slt17/slu7-100 and slt21/prp8-21 are not. This difference suggests that the latter two factors are unlikely to be involved in interactions with U2-U6 snRNA helix II but rather are specific to interactions with U2 snRNA. Pairwise synthetic lethality was observed among slt11-1 (which affects the first step of splicing) and several second-step factors, including slt15/prp17-100, slt17/slu7-100, and prp16-1. Mutations in loop 1 of U5 snRNA, a region that is implicated in the alignment of the two exons, are synthetically lethal with slu4/prp17-2 and slu7-1 (D. Frank, B. Patterson, and C. Guthrie, Mol. Cell. Biol. 12:5179-5205, 1992), as well as with slt11-1, slt15/prp17-100, slt17/slu7-100, and slt21/prp8-21. These same U5 snRNA mutations also interact genetically with certain U2 snRNA mutations that lie in the helix I and helix II regions of the U2-U6 snRNA structure. Our results suggest interactions among U2 snRNA, U5 snRNA, and Slt protein factors that may be responsible for coupling and coordination of the two reactions of pre-mRNA splicing.     

The special training month for tutors and residents in family medicine in Valencia: evaluation of 3 cases]

Decompression and stabilization have been shown to improve neurologic outcome in cases of cervical spine trauma with proven compression of the spinal cord. This paper reviews experimental and clinical research to clarify the benefits of early surgery for cervical spinal cord injury. The direct clinical benefit of early surgery is a theoretic improvement in neurologic recovery over that of delayed surgery. Additional benefits of early surgery include the clinical advantages of a decreased length of hospitalization and its associated complications and a decreased time to rehabilitation and mobilization. Proper, timely surgical intervention can better the physiologic environment so as to allow for maximum neurologic improvement.     

Implication of His68 in the substrate site of Bacillus subtilis adenylosuccinate lyase by mutagenesis and affinity labeling with 2-[(4-bromo-2,3-dioxobutyl)thio]adenosine 5'-monophosphate

Adenylosuccinate lyase of Bacillus subtilis is inactivated by 2-[(4-bromo-2,3-dioxobutyl)thio]adenosine 5'-monophosphate (2-BDB-TAMP) at pH 7.0. As the reagent concentration is increased, a maximum rate constant is approached, indicative of reversible enzyme-reagent complex formation (KR = 68 +/- 9 microM) prior to irreversible modification (kmax = 0.081 +/- 0.004 min-1). Complete inactivation occurs concomitant with about 1 mol of 2-BDB-[14C]TAMP incorporated/mol of enzyme subunit. Adenylosuccinate, or a combination of AMP and fumarate, decreases the inactivation rate and reduces incorporation of [14C] reagent, whereas either AMP or fumarate alone is much less effective. These observations suggest that 2-BDB-TAMP attacks the adenylosuccinate binding site. Proteolytic digestion of inactivated enzyme, followed by purification of the digest by HPLC, yields the radioactive peptide Ile62-Ala72, in which Arg67 and His68 are the most likely targets. Thus 2-BDB-TAMP reacts with adenylosuccinate lyase at a site distinct from the His141 attacked by 6-BDB-TAMP (Lee, Worby, Dixon, and Colman (1997) J. Biol. Chem. 272, 458-465). Site-directed mutagenesis was used to construct mutant enzymes with replacements for both Arg67 and His68, and either Arg67 or His68. The R67M mutant enzyme has almost the same specific activity as the wild-type enzyme under standard assay conditions, whereas the single mutant H68Q and double mutant R67M-H68Q enzymes exhibit specific activities that are decreased more than 100-fold. These results indicate that while Arg67 and His68 may both be in the region of the substrate site, only His68 is important for the catalytic activity of B. subtilis adenylosuccinate lyase. A role is proposed for His68 as a general acid-base catalyst.