J. H. Paul Wilson

Frequency and Spectrum of Cancers in the Peutz-Jeghers Syndrome

Background: Although an increased cancer risk in Peutz-Jeghers syndrome is established, data on the spectrum of tumors associated with the disease and the influence of germ-line STK11/LKB1 (serine/threonine kinase) mutation status are limited. Experimental Design: We analyzed the incidence of cancer in 419 individuals with Peutz-Jeghers syndrome, and 297 had documented STK11/LKB1 mutations. Results: Ninety-six cancers were found among individuals with Peutz-Jeghers syndrome. The risk for developing cancer at ages 20, 30, 40, 50, 60, and 70 years was 2%, 5%, 17%, 31%, 60%, and 85%, respectively. The most common cancers represented in this analysis were gastrointestinal in origin, gastroesophageal, small bowel, colorectal, and pancreatic, and the risk for these cancers at ages 30, 40, 50, and 60 years was 1%, 9%, 15%, and 33%, respectively. In women with Peutz-Jeghers syndrome, the risk of breast cancer was substantially increased, being 8% and 31% at ages 40 and 60 years, respectively. Kaplan-Meier analysis showed that cancer risks were similar in Peutz-Jeghers syndrome patients with identified STK11/LKB1 mutations and those with no detectable mutation (log-rank test of difference χ2 = 0.62; 1 df; P = 0.43). Furthermore, the type or site of STK11/LKB1 mutation did not significantly influence cancer risk. Conclusions: The results from our study provide quantitative information on the spectrum of cancers and risks of specific cancer types associated with Peutz-Jeghers syndrome.

The effect of growth hormone administration in growth hormone deficient adults on bone, protein, carbohydrate and lipid homeostasis, as well as on body composition

OBJECTIVE The effect on bone, protein, carbohydrate and lipid homeostasis as well as body composition of the administration of growth hormone to adult patients with growth hormone deficiency was studied.

Selective Accumulation of Endogenously Produced Porphyrins in a Liver Metastasis Model in Rats

The possibility of using the porphyrin precursor 5-aminolevulinic acid to cause selective porphyrin accumulation in tumors was examined. Syngeneic colon carcinomas CC531 were implanted in the livers of Wag/Rij rats. Groups of three to six animals each were given 2 mg/mL of 5-aminolevulinic acid in drinking water from the 8th, 14th, or 17th day after tumor implantation. Two other groups received either 2.5 or 5 mg/kg of Photofrin II (Photomedica Inc., Raritan, NJ) intravenously on day 17. On day 19 the livers were removed and porphyrin concentrations were measured in normal livers and tumors by solvent extraction and high-performance liquid chromatography. Protoporphyrin accumulated progressively in tumors with increasing duration of 5-aminolevulinic acid administration (P = 0.0001), whereas no increase was found in normal livers. After 11 days of 5-aminolevulinic acid administration the porphyrin concentration ratio between tumors and livers was 4:1. In contrast, after Photofrin II administration the concentration was higher in normal livers than in tumors (1:3 ratio, tumor to liver). Enzyme measurements showed a threefold decrease in ferrochelatase activity in tumors compared with livers (P less than 0.001). In conclusion, oral administration of 5-aminolevulinic acid results in progressive accumulation of protoporphyrin in a transplantable colon carcinoma without accumulation in the surrounding liver tissue. This selective accumulation of porphyrins appears to be caused by a relative ferrochelatase deficiency in malignant tissue. 5-Aminolevulinic acid administration may be a suitable approach to photosensitizing liver tumors for photodynamic therapy or to early detection of tumors by fluorescence in ultraviolet light.

Peutz-Jeghers syndrome: 78-year follow-up of the original family.

BACKGROUND The association between heredity, gastrointestinal polyposis, and mucocutaneous pigmentation in Peutz-Jeghers syndrome (PJS) was first recognised in 1921 by Peutz in a Dutch family. This original family has now been followed-up for more than 78 years. We did mutation analysis in this family to test whether the recently identified LKB1 gene is indeed the PJS gene in this family. METHODS The original family was retraced and the natural history of PJS was studied in six generations of this kindred by interview, physical examination, chart view, and histological review of tissue specimens. DNA-mutation analysis was done in all available descendants. FINDINGS Clinical features in this family included gastrointestinal polyposis, mucocutaneous pigmentation, nasal polyposis, and rectal extrusion of polyps. Survival of affected family members was reduced by intestinal obstruction and by the development of malignant disease. A novel germline mutation in the LKB1 gene was found to cosegregate with the disease phenotype in the original family. The mutant LKB1 allele carried a T insertion at codon 66 in exon 1 resulting in frameshift and stop at codon 162 in exon 4. INTERPRETATION The morbidity and mortality in this family suggest that PJS is not a benign disease. An inactivating germline mutation in the LKB1 gene is involved in the PJS phenotype in the original and oldest kindred known to be affected by PJS.

Current Status of Photodynamic Therapy in Oncology

SummaryPhotodynamic therapy (PDT) is a cancer treatment based on the accumulation in malignant tissue of a photosensitiser with low systemic toxicity. Subsequent illumination induces a type II photochemical reaction with singlet oxygen production that results in destruction of biomolecules and subcellular organelles.The first full clinical report of PDT dates from 1976. Haematoporphyrin derivative, a complex mixture of porphyrins, was initially used as a photosensitiser. An enriched fraction (porfimer sodium) is now the most commonly used clinical agent. After systemic administration porphyrins bind to albumin and lipoproteins. Accumulation occurs mainly in tumours and organs of the reticuloendothelial system. The light of an argon-dye laser can be tuned to the appropriate wavelength and delivered either superficially, interstitially or intraluminally. Light distribution can be assessed by using a radiation transport model and tissue optical properties, or direct measurement with light detectors.The effects of PDT depend in a complex way on: characteristics, tissue concentration and localisation of the photosensitiser; the target tissue optical properties and oxygenation; activation wavelength, power density and treatment regimen. Future research is directed towards: better photosensitisers (i.e. phthalocyanines, chlorins or protoporphyrin IX endogenously produced from 5-aminolevulinic acid); improved light generation and delivery; and combination with hyperthermia, chemotherapy, radiotherapy or surgery. Adjuvant intraoperative PDT is a promising approach to destroying residual tumour after surgery.

NOVEL MUTATIONS IN THE LKB1/STK11 GENE IN DUTCH PEUTZ-JEGHERS FAMILIES

The Peutz‐Jeghers syndrome (PJS) is a rare hereditary disorder in which gastrointestinal hamartomatous polyposis, mucocutaneous pigmentation, and a predisposition for developing cancer are transmitted in an autosomal dominant fashion. The recently identified LKB1/STK11 gene located at chromosome 19p13.3 is mutated in a number of PJS pedigrees. We performed mutation analysis in 19, predominantly Dutch, PJS families. In 12 of these families, we identified LKB1/STK11 mutations, none of which has been described before. These 12 novel LKB1/STK11 mutations consist of one nonsense mutation, three frameshift deletions, three frameshift insertions, two acceptor splice site mutations, and three missense mutations. In addition, we detected four polymorphisms in LKB1/STK11. In the remaining seven PJS families, we found no apparent abnormalities of the LKB1/STK11 gene, which could reflect the existence of locus heterogeneity in PJS. None of the mutations occurred in more than one family, and a number were demonstrated to have arisen de novo. The diverse array of mutations found, the apparent high mutation rate, as well as the existence of a possible second PJS locus, renders diagnostic or predictive genetic testing in individual patients difficult, although future identification of additional mutations or even gene(s) will help in increasing the yield of direct mutation analysis. Hum Mutat 13:476–481, 1999.

5-Aminolaevulinic acid-induced protoporphyrin IX accumulation in tissues: Pharmacokinetics after oral or intravenous administration

UNLABELLED In this study, the biodistribution of 5-aminolaevulinic acid (ALA) and accumulation of protoporphyrin IX (PpIX) in rats have been examined. Two groups of 21 WAG/Rij rats are given 200 mg/kg ALA orally or intravenously. Six rats serve as controls. At 1, 2, 3, 4, 6, 12 and 24 h after ALA administration, ALA and porphyrin concentrations are measured in 18 tissues and fluids. Liver enzymes and renal-function tests are measured to determine ALA toxicity. In both groups ALA concentration is highest in kidney, bladder and urine. After oral administration, high concentrations are also found in duodenal aspirate and jejunum. Mild, short-lasting elevation of creatinine is seen in both treatment groups. Porphyrins, especially PpIX, accumulate mainly in duodenal aspirate, jejunum, liver and kidney (> 10 nmol/g tissue), less in oesophagus, stomach, colon, spleen, bladder, heart, lung and nerve (2-10 nmol/g tissue), and only slightly in plasma, muscle, fat, skin and brain (< 2 nmol/g tissue). In situ synthesis of porphyrins rather than enterohepatic circulation contributes to the PpIX accumulation. Confocal laser scanning microscopy shows selective porphyrin fluorescence in epithelial layers. Peak levels and total production of porphyrins are equal after oral and intravenous ALA administration. IN CONCLUSION administration of 200 mg/kg ALA results in accumulation of photosensitive concentrations of PpIX, 1 to 6 h after ALA administration, in all tissues except muscle, fat, skin and brain. Knowledge of the time-concentration relationship should be helpful in selecting dosages, routes of administration and timing of ALA photodynamic therapy.

Incorporation and washout of orally administered n-3 fatty acid ethyl esters in different plasma lipid fractions

The aim of the present study was to quantify the incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into plasma lipids after oral administration of n-3 fatty acid ethyl esters, since little is known about the rate and pattern of incorporation into plasma lipid fractions. In addition, we aimed to obtain preliminary information regarding EPA half-life, which is needed to establish an optimal dosing schedule. Five healthy volunteers ingested two 8.5 g doses of n-3 fatty acid ethyl esters daily for 7 d, supplying 6.0 g EPA/d and 5.3 g DHA/d. The fatty acid compositions of plasma phospholipids (PL), cholesteryl esters (CE) and triacylglycerols (TAG) were determined during supplementation and during a washout period of 7 d. Half-lives of EPA and DHA were calculated. The proportion of EPA in PL showed a 15-fold increase after 7 d (P < 0.001), while DHA showed a smaller increase (P < 0.01). In CE, EPA also increased (P < 0.05), while DHA did not increase at all. Remarkably, incorporation of DHA into TAG was even higher than that of EPA. Half-life of EPA in PL ranged from 1.63 to 2.31 d (mean 1.97 (SE 0.15) d), whereas mean half-life of EPA in CE was 3.27 (SE 0.56) d. In three subjects, washout of EPA and DHA from TAG seemed to follow a bi-exponential pattern, with a short half-life (< 1 d) in the initial phase and a half-life of several days in the second phase. In conclusion, EPA ethyl esters are rapidly incorporated into plasma lipids, especially into PL. The relatively long half-life of EPA in plasma would permit a dosing schedule with intervals of > or = 12 h in supplementation studies.

A shift in balance between profibrinolytic and antifibrinolytic factors causes enhanced fibrinolysis in cirrhosis

The aim of this study was to assess the cause of enhanced fibrinolysis in cirrhosis by studying the balance between profibrinolytic and antifibrinolytic proteins in 24 patients with mild or severe cirrhosis. Antigen levels of both tissue-type plasminogen activator and plasminogen-activator inhibitor 1 were increased in mild and severe cirrhosis. Activity levels showed a very wide variability, but median activity levels of both proteins were normal. In most patients, the increase in tissue-type plasminogen activator was counterbalanced by the increased levels of plasminogen-activator inhibitor 1, but in a subgroup of patients the change in balance resulted in extremely high tissue-type plasminogen-activator levels. The specific activity of both proteins (activity/antigen quotient) was reduced in either mild or severe cirrhosis. This finding indicates either that more enzyme-inhibitor complexes circulate in the blood of patients with cirrhosis than in normal individuals or that dysfunctional molecules circulate. Plasminogen and alpha 2-antiplasmin antigen and activity levels were decreased in both mild and severe cirrhosis. The binding of alpha 2-antiplasmin to fibrin was decreased in severe cirrhosis, making fibrin clots more susceptible to lysis. Clot lysis experiments were performed to see if equal decreases in plasminogen and alpha 2-antiplasmin levels, as found in cirrhosis, result in a change in the rate of fibrinolysis. It was found that the proportionate decreases led to enhancement of fibrinolysis, indicating that the inhibitor depletion is more important than the proenzyme depletion. The authors conclude that enhanced fibrinolysis frequently found in cirrhosis may be attributed to an increased tissue-type plasminogen-activator activity relative to plasminogen-activator-inhibitor activity and decreased levels of alpha 2-antiplasmin, resulting in a reduced binding of alpha 2-antiplasmin to fibrin.

The difference in liver pathology between sporadic and familial forms of porphyria cutanea tarda: the role of iron

Porphyria cutanea tarda is a disorder of porphyrin metabolism, of which familial and sporadic forms have been described. Factors such as iron seem necessary for porphyria cutanea tarda to become clinically manifest. To study the relationship between iron and uroporphyrins in hepatocytes of patients with porphyria cutanea tarda, a morphological and morphometrical study was performed in 13 liver biopsies of patients with porphyria cutanea tarda (eight with sporadic porphyria cutanea tarda and five with familial porphyria cutanea tarda). In addition, possible differences in clinical and biochemical features and in histopathological findings between patients with sporadic porphyria cutanea tarda and familial porphyria cutanea tarda were investigated. Familial porphyria cutanea tarda patients presented at a younger age than sporadic porphyria cutanea tarda patients (42.4 +/- 5.3 vs. 57.3 +/- 8.6 years). Biochemical features were not different between sporadic porphyria cutanea tarda and familial porphyria cutanea tarda patients. Uroporphyrin crystals and a variable degree of liver siderosis were detected in the biopsies of all 13 patients. Uroporphyrin crystals were often found close to ferritin-like iron deposits. The morphometrical analysis showed that an increased mean area fraction of ferritin iron was associated with an increased mean area fraction of uroporphyrin crystals in hepatocytes of sporadic porphyria cutanea tarda and familial porphyria cutanea tarda patients. Moreover, the amount of uroporphyrin crystals was significantly higher in livers of familial porphyria cutanea tarda than sporadic porphyria cutanea tarda patients. These findings are consistent with the hypothesis that uroporphyria is precipitated by an iron-dependent process.(ABSTRACT TRUNCATED AT 250 WORDS)