Size-induced transition from magnetic ordering to kondo behavior in (Ce,Al) compounds

Magnetic ordering and Kondo behavior coexist in three (Ce,Al)-based compounds: CeAl2, Ce3Al, and Ce3Al11. A common feature apparently independent of crystal structures also prevails in terms of the size-induced transition between these two magnetic phenomena. As the particle size is reduced to nanoscale, the specific heat anomaly associated with the magnetic ordering diminishes. Although the Kondo temperature also decreases, the entropy associated with Kondo anomaly exhibits a large increase. This results in an enhancement of the Kondo behavior and an increased coefficient gamma of the linear term in specific heat. For example, in 80 A CeAl2 the extrapolated r(0) reaches 9000 mJ mol Ce-1 K-2.

Severe bronchiectasis in patients with "cystlike" structures within the ciliary shafts

Cilia are minute hairlike structures which sweep the respiratory tract clean by continuous beating. Ciliary dysfunction can occur which leads to development of bronchiectasis. We describe the clinical and investigation profiles of four patients who had early-onset severe and otherwise idiopathic bronchiectasis associated with a previously undescribed ciliary defect in which numerous cystlike structures are present within the ciliary shafts. The patients had otherwise normal ciliary microtubular ultrastructure and central microtubular orientation. Our newly described ciliary abnormality appears to be a primary defect and more systematic studies should be performed to evaluate this further.

Modifications of the cyclic mu receptor selective tetrapeptide Tyr-c[D-Cys-Phe-D-Pen]NH2 (Et): effects on opioid receptor binding and activation

The previously described cyclic mu opioid receptor-selective tetrapeptide Tyr-c[D-Cys-Phe-D-Pen]NH2 (Et) (JOM-6) was modified at residues 1 and 3 by substitution with various natural and synthetic amino acids, and/or by alteration of the cyclic system. Effects on mu and delta opioid receptor binding affinities, and on potencies and efficacies as measured by the [35S]-GTPgammaS assay, were evaluated. Affinities at mu and delta receptors were not influenced dramatically by substitution of Tyr1 with conformationally restricted phenolic amino acids. In the [35S]-GTPgammaS assay, all of the peptides tested exhibited a maximal response comparable with that of fentanyl at the mu opioid receptor, and all showed high potency, in the range 0.4-9nM. However, potency changes did not always correlate with affinity, suggesting that the conformation required for binding and the conformation required for activation of the opioid receptors are different. At the delta opioid receptor, none of the peptides were able to produce a response equivalent to that of the full delta agonist BW 373,U86 and only one had an EC50 value of less than 100nM. Lastly, we have identified a peptide, D-Hat-c[D-Cys-Phe-D-Pen]NH2 (Et), with high potency and > 1,000-fold functional selectivity for the mu over delta opioid receptor as measured by the [35S]-GTPgammaS assay.

Sputum elastase in steady-state bronchiectasis

STUDY OBJECTIVES

To study the correlations between sputum elastase output with clinical and sputum inflammatory and microbial factors in steady-state bronchiectasis.

DESIGN

Prospective recruitment of patients with bronchiectasis (17 women; 48.5 +/- 16.5 years old; FEV(1)/FVC, 1.3 +/- 0.6/2.1 +/- 0.9) for assessment of 24-h sputum output of elastase, bacteria, leukocytes, interleukin (IL)-1beta, IL-8, tumor necrosis factor-alpha, and leukotriene B(4). Clinical variables assessed concomitantly included 24-h sputum volume, lung spirometry, number of lung lobes affected by bronchiectasis, and exacerbation frequency.

SETTING

Consecutive recruitment of outpatients (n = 30) in steady-state bronchiectasis.

MEASUREMENTS AND RESULTS

Twenty-four-hour sputum elastase output correlated with 24-h sputum volume (r = 0.79, p = 0.0001); number of bronchiectatic lung lobes (r = 0.54, p = 0.0026); percent predicted FEV(1) (r = -0. 48, p = 0.0068); percent predicted FVC (r = -0.49, p = 0.001); and leukocyte output (r = 0.75, p = 0.0001). There was no correlation between the sputum output of bacteria with either inflammatory or enzymatic factors (p > 0.05).

CONCLUSION

Our data highlight the importance of elastase and the possibility of independent roles for enzymatic, inflammatory, and microbial components in the pathogenesis of bronchiectasis. Further research on novel therapy targeting each of these components should be pursued.

A study on pruritus after parathyroidectomy for secondary hyperparathyroidism

BACKGROUND

The effective therapy for uremic pruritus remains a clinical challenge, and the factors affecting the pruritus before and after parathyroidectomy have not been defined.

STUDY DESIGN

Thirty-seven patients were operated on for secondary hyperparathyroidism. Their ages ranged from 14 to 73 years, and the duration of dialysis from 12 to as long as 168 months. Indications for surgery were skin itch in 22 patients and other reasons in 15 patients. Serum levels of calcium, phosphorus, intact PTH (i-PTH), and alkaline phosphatase were checked at two different intervals-before surgery and 1 week after operation. Immunohistochemical stain of mast cells, antihuman macrophage (CD68), antihuman dendritic reticulum cell (CD35), and i-PTH (IHPTH) were performed on skin specimens. Skin samples were prepared into tissue homogenates and analyzed for concentrations of interleukin-2 (II-2) and tumor necrosis factor-alpha (TNF-alpha). II-2 and TNF-alpha were measured by sandwich enzyme-linked immunosorbent assay. The extent of pruritus was evaluated on a visual analog scale (VAS) ranging from 0 to 10 and a behavior rating scale (BRS) ranging from 0 to 5, at a preoperative stage and 1 week after operation.

RESULTS

Serum levels of calcium, phosphorus, the product of calcium and phosphorous (Ca x P), alkaline phosphatase, and i-PTH changed significantly after parathyroidectomy. The VAS decreased from 5.4 +/- 3.2 to 1.8 +/- 1.5 (p < 0.001). Significant improvement of BRS was achieved 1 week after surgery (p < 0.001), and in the followup period. Before surgery, there was no correlation between serum levels of calcium, phosphorus, Ca x P, alkaline phosphatase, i-PTH, number of mast cells, CD68, CD35, and IHPTH, and the scale of itch estimated with either VAS or BRS. The tissue levels of Il-2 and TNF-alpha were not detectable in any of them. We noted that high levels of phosphorus and Ca x P affected the postoperative extent of pruritus. But a linear regression test showed Ca x P was the only factor affecting postoperative itch.

CONCLUSIONS

Pruritus in patients with secondary hyperparathyroidism can be reduced by parathyroidectomy. Apparently, high-level Ca x P is the only factor that seems to affect the postoperative extent of pruritus.

Acute fish liver intoxication: report of three cases

The livers of some larger fish such as shark, tuna and seabass have been reported to be responsible for a peculiar poisoning causing headaches and desquamation. This type of poisoning can also be induced by ingestion of the livers of the sea whale, the polar bear and the seal. Since these animals contain an extremely large quantity of vitamin A in their livers and the symptoms of poisoning in the patients resembled those of patients with acute hypervitaminosis A, the poisoning was believed to have been caused by excessive vitamin A intake. We observed an episode of acute fish liver intoxication in which 3 man experienced dizziness, headache, blurred vision, nausea, vomiting, fever, and desquamation after ingesting the liver of the grouper fish Cephalopholis boenak (C. boenak). One of the patients had full-blown symptoms and presented with a high fever, headache, dizziness, generalized aching pain, and superficial vesicles and bullae of the skin. The treatment was mainly supportive. In the follow-up period, he subsequently developed hair loss and diffuse peeling of the skin on his palms and soles. Acute fish liver intoxication is rare, especially in subtropical regions. Symptomatologically, the clinical pictures of these patients were comparable to acute hypervitaminosis A or retinoid intoxication. The average vitamin A content in the grouper (C. boenak) is high enough to cause acute vitamin A intoxication. Moreover, ethanol may play a potentiating role in this type of event.

Magnetic properties of Ni-Co-Cr-base Elgiloy

The Ni-Co-Cr-base Elgiloy is one of the commonly used engineering materials. Most applications rely on its high strength, ductility, corrosion resistance and excellent fatigue life over a wide temperature range. However, in the medical application of cerebral aneurysm clips, the alloy is often subjected to strong magnetic fields associated with magnetic resonance imaging (MRI). Its paramagnetic behavior meets MRI safety requirements, but is the source of relatively large artifacts and thus less MRI-compatible for MRI procedure involving the brain. This article reports superconducting quantum interference device (SQUID) measurements on the magnetic properties of a series of Elgiloy wires in either as-drawn or heat-treated conditions. Furthermore, low-temperature calorimetry was employed to reveal the existence of submicroscopic clusters containing ferromagnetic elements such as Ni or Co in the macroscopically paramagnetic matrix.

Comparison of preference and ease-of-use of breath-actuated inhalation devices in children

This study was conducted to evaluate children's and nurses' preference among the three breath-actuated devices, Turbuhaler (Astra), Autohaler (3M) and Accuhaler (Glaxo-Wellcome). This was an open study conducted in the paediatric in-patient department of Kwong Wah Hospital, Hong Kong. Subjects over 6 years of age who had not previously used any inhalation devices were recruited. The three devices were in random order. The preferences of subjects and nurses were ranked in a three-point scale. The children had a statistically significant preference for Accuhaler, while the nurses preferred to teach both Accuhaler and Autohaler but not the Turbuhaler.

Frequent microsatellite instability and mismatch repair gene mutations in young Chinese patients with colorectal cancer

BACKGROUND

The incidence of colorectal cancer in persons under 46 years of age is substantially higher in Hong Kong than in Scotland and many other countries. Consequently, we examined whether there is a hereditary predisposition for colorectal cancer in this Southern Chinese population.

METHODS

We investigated the incidence of microsatellite instability (MSI) at 10 DNA sites in 117 colorectal cancer specimens from Chinese patients of various ages. Those tumors with new alleles at 40% or more of the sites investigated were identified as highly unstable MSI (MSI-H). In young patients, we also searched for germline mutations in three mismatch repair genes (hMSH2, hMLH1, and hMSH6).

RESULTS

The incidence of MSI-H varied statistically significantly with age, being observed in more than 60% of those younger than age 31 years at diagnosis and in fewer than 15% of those age 46 years or older. In 15 patients (<46 years old) whose colorectal cancers showed MSI-H, eight possessed germline mutations in either hMSH2 or hMLH1. When mutations in hMSH6 were included, more than 80% of Chinese colorectal cancer patients younger than 31 years had germline mutations in mismatch repair genes. We found a novel germline missense mutation in hMSH6 in a 29-year-old man whose tumor showed no MSI. Two patients had a 4-base-pair insertion in exon 10 causing a truncated protein; this insertion is a common polymorphism with a population allele frequency in Chinese of 5.6%.

CONCLUSIONS

Our results indicate that germline mutations in mismatch repair genes contribute substantially to the pathogenesis and high incidence of colorectal cancer in young Hong Kong Chinese. However, because young Chinese and Caucasians show similar proportions of colorectal cancers with MSI-H, despite the higher incidence in the former, additional factors may underlie the high susceptibility of young Chinese to colorectal cancer.

Use of infrared emission detection thermometer in Chinese neonates

OBJECTIVE

To evaluate the reproducibility of Thermoscan, an infrared emission detection ear thermometer, and to establish the normal reference range of ear temperature in Chinese neonates.

METHODS

Neonates were recruited from the inpatients population with exclusion of those suffering from infections.

RESULTS

Forty-nine neonates were recruited with 1,115 temperature taking sessions. Mean left ear temperature was 36.64 degrees C +/- 0.35 degree C. Mean right ear temperature was 36.64 degrees C +/- 0.37 degree C. Clinical repeatability for left and right ear was 0.17 degree C and 0.17 degree C, respectively.

CONCLUSION

Thermoscan produced reproducible results in Chinese neonates. The normal range of ear temperature for Chinese neonates is 35 degrees C to 37 degrees C. Ear temperature > 37.8 degrees C should be regarded as fever.

Helicobacter pylori in Meckel's diverticulum with heterotopic gastric mucosa in a population with relatively high H. pylori prevalence rate

BACKGROUND

Helicobacter pylori (H. pylori) colonize only foveolar gastric-type mucosa and are associated with active chronic gastritis and peptic ulcer. The aim of this study was to investigate whether H. pylori can also be found in Meckel's diverticulum which contains heterotopic gastric mucosa.

METHODS

Biopsy specimens of Meckel's diverticulum resected in Queen Mary Hospital, University of Hong Kong, during the 10 year period 1986-1995 were retrieved and reviewed. Those containing gastric heterotopia were examined for the presence of H. pylori, using Warthin-Starry silver stain.

RESULTS

In the 59 cases of Meckel's diverticula studied, 16 were found to contain heterotopic gastric mucosa. Helicobacter pylori were not identified in any of these cases. In one of the 16 patients a concomitant gastric biopsy was performed. Although the gastric mucosa of this patient was heavily colonized by H. pylori, again no H. pylori was found in the heterotopic gastric mucosa in the Meckel's diverticulum.

CONCLUSIONS

The absence of H. pylori in all the Meckel's diverticula examined, even when the stomach was heavily colonized by the organisms, suggests that colonization of Meckel's diverticulum by H. pylori is a rare event. This, together with the overall rarity of H. pylori in all reported series of Meckel's diverticulum, argues against its causative role in complications of Meckel's diverticulum.

Microsatellite instability, Epstein-Barr virus, mutation of type II transforming growth factor beta receptor and BAX in gastric carcinomas in Hong Kong Chinese

Microsatellite instability (MI), the phenotypic manifestation of mismatch repair failure, is found in a proportion of gastric carcinomas. Little is known of the links between MI and Epstein-Barr virus (EBV) status and clinicopathological elements. Examination of genes mutated through the MI mechanism could also be expected to reveal important information on the carcinogenic pathway. Seventy-nine gastric carcinomas (61 EBV negative, 18 EBV positive) from local Hong Kong Chinese population, an intermediate-incidence area, were examined. Eight microsatellite loci, inclusive of the A10 tract of type II transforming growth factor beta receptor (TbetaR-II), were used to evaluate the MI status. MI in the BAX and insulin-like growth factor II receptor (IGF-IIR) genes were also examined. High-level MI (>40% unstable loci) was detected in ten cases (12.7%) and low-level MI (1-40% unstable loci) in three (3.8%). High-level MI was detected in two EBV-associated cases (11%) and the incidence was similar for the EBV-negative cases (13%). The high-level MIs were significantly associated with intestinal-type tumours (P = 0.03) and a more prominent lymphoid infiltrate (P = 0.04). Similar associations were noted in the EBV-positive carcinomas. The high-level MIs were more commonly located in the antrum, whereas the EBV-associated carcinomas were mostly located in body. Thirteen cardia cases were negative for both high-level MI and EBV. All patients aged below 55 were MI negative (P = 0.049). Of the high-level MIs, 80% had mutation in TbetaR-II, 40% in BAX and 0% in IGF-IIR. Of low-level MIs, 33% also had TbetaR-II mutation. These mutations were absent in the MI-negative cases. Of three lymphoepithelioma-like carcinomas, two cases were EBV positive and MI negative, one case was EBV negative but with high-level MI. In conclusion, high-level MIs were present regardless of the EBV status, and were found in a particular clinicopathological subset of gastric carcinoma patient. Inactivation of important growth regulatory genes observed in these carcinomas confirms the importance of MI in carcinogenesis.

hMLH1 promoter methylation and lack of hMLH1 expression in sporadic gastric carcinomas with high-frequency microsatellite instability

Mutation of DNA mismatch repair genes has rarely been documented in sporadic gastric carcinoma with microsatellite instability (MSI). In sporadic colorectal carcinoma, hMLH1 promoter methylation associated with protein loss is found in the majority of high-frequency MSI cases. We investigated a series of 35 sporadic gastric carcinomas stratified into high-frequency MSI (MSI-H), low-frequency MSI (MSI-L) and microsatellite stable (MSS) groups and found that hypermethylation of the CpG island in the hMLH1 promoter region was present in 100% of MSI-H sporadic gastric carcinomas. In 90% of cases, there was an associated complete loss of hMLH1 protein, as detected by immunohistochemistry, and a markedly lowered hMLH1 mRNA level. This loss of hMLH1 protein occurred in the MSI-H invasive tumor but not in the adjacent carcinoma-in situ or dysplastic components that were MSS. The MSI-L and MSS forms of gastric carcinoma all showed predominantly unmethylated hMLH1 promoter, positive hMLH1 protein and high hMLH1 mRNA level. On the other hand, hMSH2 protein was expressed in all of the tumors irrespective of the MSI status. Our results suggest that high-frequency MSI in sporadic gastric cancer is mostly due to epigenetic inactivation of hMLH1 in association with promoter methylation, and the loss of hMLH1 protein is a significant event in the development of invasive tumor.

Defective IL-2 receptor expression in lymphocytes of patients with arsenic-induced Bowen's disease

The immune function of peripheral mononuclear cells (MNC) in patients with endemic arsenic-induced Bowen's disease (BD) was investigated. Many cytokines and immune-related factors were determined in the present study. Interleukin-1beta and TNF-alpha production was used as an indicator of monocyte/macrophage function. II-2 and sIL-2R production was used as an indicator of lymphocyte activation. The release of sCD4 and sCD8 was used as an indicator of activation of respective T-cell subpopulations. Production of IFN-gamma and IL-2 reflected the cellular effector function of helper T-cells type 1. In vivo cell-mediated immunity was also assessed by estimation of the percentage of T-cells in peripheral blood MNC and the nonspecific delayed-type hypersensitivity (DTH) response to 2,4-dinitrochlorobenzene (DNCB). Both assays revealed depressed cell-mediated immunity in BD. Compared with healthy controls, spontaneous and PHA-induced IFN-gamma and TNF-alpha production was significantly decreased in BD whereas spontaneous release of IL-2, sCD4 and sCD8 was significantly increased. Although PHA stimulation increased IL-2 release, the expression of IL-2R alpha and beta chains and the release of sIL-2R were not proportionately increased in BD. In addition, IL-2-mediated [3H]-thymidine incorporation by MNC in patients with BD was significantly decreased. These findings suggest that the defective cell-mediated immune function in BD is due to impairment of membrane IL-2R expression in lymphocytes after stimulation.

A high affinity, mu-opioid receptor-selective enkephalin analogue lacking an N-terminal tyrosine

We report a high affinity, mu opioid receptor selective enkephalin analogue in which the N-terminal tyrosine residue thought to be required for such high affinity is replaced by phenylalanine. The high affinity can be traced to a shift of the ligand's N-terminal residue within the mu receptor binding pocket, which diminishes the importance of the usual hydrogen bond between the tyrosine phenolic moiety and the receptor.

Birthplace and yield of nipple aspirate fluid in Chinese women

The different rates of breast cancer found between Chinese women in Asia compared with Chinese-born women in the United States suggest that dietary and environmental factors may be of etiological significance. We evaluated the proportion of 480 premenopausal Chinese women who yielded nipple aspirate fluid (NAF) by birthplace in Asia versus the United States and by reproductive and other risk factors. Birthplace was used as a surrogate for presumed differences in exposures during gestation, childhood, and adolescence that might influence yield of NAF in premenopausal women. In United States-born Chinese women compared with Asia-born Chinese women, the proportion yielding NAF was 44 of 95 (46.3%) versus 120 of 385 (31.2%), respectively. The relative risk of yield of NAF in United States-born women compared with Asia-born women was odds ratio = 2.37 (95% confidence interval, 1.26-4.47). Independent positive associations of NAF yield were also found with history of parity and breast feeding, cerumen phenotype, and a negative association with ever use of oral contraceptives. These findings support the hypothesis that early environmental exposures may have long-lasting physiological effects discernible in the breast glands of adult women.

Paediatric upper gastrointestinal endoscopy: a 2-year review

OBJECTIVE

To review the paediatric upper gastrointestinal endoscopy service in a paediatric department in Hong Kong.

METHODS

Records of all endoscopies undertaken in this department from May 1995 to January 1996 were retrieved and analysed.

RESULTS

The commonest indication for upper endoscopy was dyspepsia with 88% positive histological findings. Helicobacter pylori (H. pylori) was found in 25% of this group of children.

CONCLUSION

Paediatric upper gastrointestinal endoscopy service is invaluable in a paediatric department by providing useful diagnostic information which would otherwise be missed.

Colorectal carcinoma in Hong Kong: epidemiology and genetic mutations

The incidence of colorectal carcinoma is rising at an alarming pace in Asian urban societies such as Hong Kong. Detailed examination of the epidemiological pattern and genetic mutation of colorectal cancer in the Hong Kong Chinese population is overdue. We compared the reported age incidence of colorectal carcinoma in Hong Kong with that of Scotland and other countries. Hong Kong showed a much higher incidence of colorectal carcinoma among the young age groups. By comparison with other countries, this raised incidence among the young appeared to be related to southern Chinese societies. The recent dramatic rise in colorectal cancer in Hong Kong was largely attributable to an increase in the over 50 years age group, while the young incidence remained unchanged. We also defined the mutation spectrum of p53 and Ki-ras in 67 unselected cases by direct DNA sequencing. Interestingly, insertion/deletion mutations in p53 from colorectal carcinoma in Hong Kong showed a significantly higher frequency (17.2%) than the Scottish data (0%) and the world database (6.6%), although the overall frequency of p53 mutation (43%) in Hong Kong was similar to others. The high incidence of colorectal carcinoma in young people and the raised proportion of frameshift mutations in p53 encourage further search for a genetic basis for susceptibility to this disease in the Hong Kong Chinese population.

Titanium aneurysm clips: Part I--Mechanical, radiological, and biocompatibility testing

Most aneurysm clips are made of cobalt-based alloys. Although these clips are nonferromagnetic, they still produce artifact that degrades the quality of magnetic resonance (MR) images. A new aneurysm clip of pure titanium was developed to minimize artifact on postoperative MR images. We evaluated these clips in a series of mechanical tests in vitro, biocompatibility tests in rabbits, and radiological tests in greyhound dogs. The clip sizes and shapes matched those of conventional aneurysm clips. The average closing forces ranged between 151.6 and 181.8 g and were not diminished by repeated sterilization or stress. After > 20 million cycles of high-pressure and high-frequency pulsations, the clips did not open and the closing forces were not reduced. Titanium aneurysm clips implanted in the subarachnoid space of 12 rabbits for 1 or 6 months produced mild gliosis identical to that produced by implantation of cobalt alloy clips in 12 control rabbits. Based on pre- and postoperative weights and electron microscopic scans, the titanium implants did not corrode. The artifact on computed tomographic and MR imaging produced by a titanium clip placed on the internal carotid artery of a greyhound was less than that produced by an identical cobalt-chrome alloy clip by a factor of two to three. This study demonstrated that titanium aneurysm clips are mechanically equivalent to conventional clips, biocompatible, and corrosion resistant. Furthermore, titanium clips have superior imaging characteristics, creating less computed tomographic and MR imaging artifact and permitting better resolution of anatomic structures than cobalt alloy clips.

Thymine dimer-dependent incision on ultraviolet light damaged-DNA in cell-free extracts of Chlorella pyrenoidosa

Cell-free extracts of the unicellular algae Chlorella pyrenoidosa induce a UV-dependent incision of both phi x 174 RFI DNA and a 27-mer double-stranded oligonucleotide containing a single thymine dimer, as analyzed by agarose and denaturing polyacrylamide gel electrophoresis, respectively. The incision reaction occurred only on the thymine dimer-containing strand of the 27-mer, and a major incision product of 17-mer was observed. Addition of ATP or ATP-regenerating system to algal extracts increased the effect of DNA incision.

The effect of nicotine and its interaction with carbon tetrachloride in the rat liver

In order to study the effects of nicotine on liver, groups of rats were given nicotine doses that simulated those seen in chronic smoking (54 and 108 mumol/l of nicotine) for 10 days. A subgroup was also given a single subcutaneous injection of 6 g/kg of carbon tetrachloride (CCl4) shortly before the animals of the group were killed. Histology demonstrated a significant hepatotoxic effect in the group receiving 108 mumol/l of nicotine when compared with the control group in the form of fatty change, focal or confluent necrosis and dark-cell change. The effects in pregnant rats were less severe. Carbon tetrachloride alone induced significant fatty change and focal necrosis in non-pregnant rats but not in pregnant rats. Nicotine also aggravated the CCl4 induced pathological changes in livers of both non-pregnant and pregnant animals. Thus nicotine alone, when given at a concentration of 108 mumol/l, exerted hepatotoxic effects; the alkaloid also aggravated the hepatotoxicity of CCl4. Pregnant rats were more resistant to the hepatotoxic effects produced by nicotine and CCl4.

Flow cytometric analysis of DNA ploidy in hepatocellular carcinoma

To examine the prognostic and pathobiologic significance of DNA content, the authors studied the surgically resected hepatocellular carcinomas of 69 patients by flow cytometric analysis. Homogeneity of DNA content within individual tumor nodules was present in 15 (88%) of 17 specimens examined. Similarly, homogeneity of DNA content in tumors having multiple nodules was found in 8 (73%) of 11 specimens. In 64 tumors with homogeneous DNA content evaluated further, DNA aneuploidy was present in 30 (46.9%) specimens, and the proportion of aneuploid tumors was similar in the large (> 5 cm in diameter, n = 35) and small (< or = 5 cm, n = 25) lesions, at 42.9% and 40%, respectively. Overall, the diploid tumors had serum alpha-fetoprotein levels increased to greater than 500 micrograms/mL more frequently than did the aneuploid tumors (P = .037). DNA content did not correlate significantly with hepatitis B surface antigen, presence of liver cirrhosis, cellular differentiation, tumor size, or tumor encapsulation. DNA content also did not influence tumor invasiveness in terms of liver invasion, presence of tumor microsatellites, or venous permeation. With multivariate Cox regression analysis, tumor encapsulation (P = .015), negative resection margin (P = .007), and DNA ploidy pattern stratified according to large and small tumors (P = .024) were favorable prognostic factors. In the small tumors, a diploid DNA pattern was associated with significantly better patient survival than was an aneuploid pattern (P = .012). In the large tumors, on the contrary, a diploid pattern was associated with poorer patient survival than was an aneuploid pattern (P = .029). The authors conclude that DNA ploidy pattern in hepatocellular carcinomas is homogeneous and stable. It supplements other predictors in prognostication when the lesions are stratified into small and large ones by tumor size. It is of particular importance as a predictor because it can be assessed preoperatively in needle-biopsy specimens.

[Pilomatricoma-a clinicopathological analysis of 22 cases, including 2 cases of bullous pilomatricoma]

Twenty-two patients with pilomatricoma seen from January 1986 to October 1990 were analyzed retrospectively. The incidence of pilomatricoma in our dermatopathologic material is 1 in every 50 cases of skin tumors. Male to female ratio is 1:2. Half of the tumors appeared before the age of 30. Most of the tumors develop in the head, neck and upper extremities. Two pilomatricomas appeared with overlying bullae. Pathologically, multiple dilated lymphatics in the dermis were found above the typical nests of shadow cells and basophilic cells. Clues to clinical diagnosis are summarized below. The stony hard, deep-seated tumor, covered by normal skin, is usually located in the upper extremity. Tumors with blue-red discoloration, firm or elastic, frequently found in eyelid and face, are located more superficially, clinically they should be differentiated from epidermal cysts. Erythematous protruding tumors occur in the scalp or face. Bullous pilomatricoma is characteristically manifested as a flaccid, thick-walled bulla with an underlying palpable hard nodule, usually seen in the shoulder, upper arm or the head.

Effect of a silicone fit-indicator on crown retention in vitro

The use of a silicone fit-indicator significantly reduced crown cementation strength. Cleaning with a metal cleaner before cementation did not reverse the effect.

The fragile-X syndrome

The variability in behavioral manifestations of the fragile-X syndrome and the lack of a well-defined psychological profile require the attention of behavioral geneticists and other behavioral scientists. The association with autism suggests that the fra(X) may be responsible for a genetic subtype of autism. While the fragile-X syndrome is considered an X-linked disorder, several aspects of observed transmission patterns do not follow those of classical X-linked inheritance. In particular, the finding of genetic transmission via intellectually normal males is surprising and has important implications for genetic counseling, as well as for genetic models of the fragile-X syndrome. Reports on folic acid treatment are encouraging, but not conclusive. The mechanisms involved in the association between the fra(X) chromosome and its particular phenotype are still unknown. Current investigations applying advanced techniques in molecular biology are likely to provide insight into this unique genetic disorder.

Probenecid disposition by parallel Michaelis-Menten and dose-dependent pseudo-first-order processes

Re-evaluation of published data on the urinary excretion of probenecid [4-(dipropylamino)sulfonylbenzoic acid, 1] and its metabolites as a function of orally administered dose has revealed that the elimination process is comprised of five parallel pathways. Excretion of the major metabolite, the acyl glucuronide 2 (35-45% of dose), follows Michaelis-Menten kinetics. The three oxidized metabolites, the mono-N-propyl, carboxylic acid, and secondary alcohol derivatives 3, 4, and 5, respectively, (totaling 30% of dose), each adhere to pseudo-first-order kinetics in which the elimination rate constant, as a result of product inhibition, is a function of the administered dose. Four to 13% of the dose is eliminated unchanged in apparent first-order fashion. A mathematical relationship between elimination half-life and dose, under conditions of product inhibition, is derived. Computer simulation of the elimination process confirms the experimental observation that the fraction of dose excreted in the form of each metabolite remains relatively constant over the dose range of 0.5 to 2 g. This study is believed to represent the first application of parallel Michaelis-Menten and dose-dependent pseudo-first-order processes to drug disposition. It demonstrates that the observation of constant proportions of excreted metabolites over a relatively wide range of doses does not provide evidence that the elimination process remains first-order.

Spontaneous regression of hepatocellular carcinoma: a case study

A Chinese patient with documented hepatocellular carcinoma (HCC) satisfied the criteria of Everson and Cole for spontaneous regression of malignant tumors. Subsequently he survived a tumor-free period of at least 13 years. During the period of regression, shrinkage of liver coincided with a rise of SGOT to a level comparable to that reported for patients with liver cancer during hepatic arterial ligation and cytotoxic therapy. Postregression liver biopsy from the site of the previous tumor revealed relatively uninflamed HBsAg-positive tissue without dysplasia. The case provided the positive end of the survival spectrum in HCC, evidence that regression of HCC might occur by involution rather than maturation, and histologic data suggesting that regressed HCC might be replaced by surrounding tissue instead of leaving behind dysplasia.

Spontaneous regression of hepatocellular carcinoma: a case study

A Chinese patient with documented hepatocellular carcinoma (HCC) satisfied the criteria of Everson and Cole for spontaneous regression of malignant tumors. Subsequently he survived a tumor-free period of at least 13 years. During the period of regression, shrinkage of liver coincided with a rise of SGOT to a level comparable to that reported for patients with liver cancer during hepatic arterial ligation and cytotoxic therapy. Postregression liver biopsy from the site of the previous tumor revealed relatively uninflamed HBsAg-positive tissue without dysplasia. The case provided the positive end of the survival spectrum in HCC, evidence that regression of HCC might occur by involution rather than maturation, and histologic data suggesting that regressed HCC might be replaced by surrounding tissue instead of leaving behind dysplasia.

Spontaneous regression of hepatocellular carcinoma: a case study

A Chinese patient with documented hepatocellular carcinoma (HCC) satisfied the criteria of Everson and Cole for spontaneous regression of malignant tumors. Subsequently he survived a tumor-free period of at least 13 years. During the period of regression, shrinkage of liver coincided with a rise of SGOT to a level comparable to that reported for patients with liver cancer during hepatic arterial ligation and cytotoxic therapy. Postregression liver biopsy from the site of the previous tumor revealed relatively uninflamed HBsAg-positive tissue without dysplasia. The case provided the positive end of the survival spectrum in HCC, evidence that regression of HCC might occur by involution rather than maturation, and histologic data suggesting that regressed HCC might be replaced by surrounding tissue instead of leaving behind dysplasia.

Liver cell dysplasia in association with hepatocellular carcinoma, cirrhosis and hepatitis B surface antigen in Hong Kong

Liver-cell dysplasia was identified in 60% of 558 cases of cirrhosis with and without hepatocellular carcinoma (HCC) in Chinese coming to necropsy in Hong Kong from 1963 to 1978. A significant correlation was found between liver-cell dysplasia and the identification of hepatitis B surface antigen (HBsAg) in the livers, suggesting that dysplasia may be casually related to hepatitis B virus (HBV). Applying Bayes' theorem to our series of male deaths, we calculated that for Chinese male non-cirrhotics showing liver-cell dysplasia at necropsy, compared with male non-cirrhotics showing no liver-cell dysplasia, the approximate risk factor for HCC is 13:1, whereas for male cirrhotics with liver-cell dysplasia, the risk factor for HCC is approximately 2:1. In the presence of dysplasia, the risk for HCC is increased two-fold in males who are also HBsAg-positive. Thus, the presence of liver-cell dysplasia in cirrhotic or non-cirrhotic livers accompanies a significantly higher risk of developing HCC, especially in the presence of HBsAg.

Hepatitis B surface antigen, hepatocellular carcinoma and cirrhosis in hong kong: a necropsy study: 1963-1976

Hepatitis B surface antigen (HBsAg) was stained in liver tissue in 71% of 496 cases of cirrhosis with and without hepatocellular carcinoma (HCC) in Chinese coming to necropsy in Hong Kong from 1963-1976. Male cases numbered 417; HBsAg was positive in 83% of those in which HCC was combined with cirrhosis and in 62% of those with cirrhosis alone. Of 39 additional male cases of HCC without cirrhosis, 38% were HBsAg+. Similar proportions were recorded in the famale cases. This progression suggests a cumulative carcinogenic effect of persistent hepatitis B virus (HBV) fully expressed in the presence of cirrhosis. The approximate risk factors for males in Hong Kong who are HBsAg+ at the time of death, compared with HBsAg- males, are 6:1 for HCC alone, 16:1 for cirrhosis alone and 50:1 for HCC combined with cirrhosis. The frequency of HBsAg+ tests is much higher in Hong Kong than in the United Kingdom, and cirrhosis is calculated to be 2.8 times and HCC 11 times commoner. The high incidence of HCC in Hong Kong is not attributable solely to the high incidence of cirrhosis, but can be related to the high incidence of cirrhosis accompanied by persistent HBV.

Isolation of plasma membranes from rat lungs: effect of age on the subcellular distribution of adenylate cyclase activity

A simple and rapid method of isolating plasma membranes from rat lungs is described. The method involves homogenization of tissue in isotonic sucrose-buffered medium followed by differential and sucrose density gradient centrifugation. Plasma membranes obtained by this procedure were essentially free from other subcellular contamination. Plasma membranes isolated from 2-day-old rat lungs showed 6 to 7-fold purification of adenylate cyclase and 5'-nucleotidase activities compared to the original homogenate. In contrast, plasma membranes from 35-day-old rat lungs showed no purification of adenylate cyclase activity although 5'-nucleotidase activity showed similar enrichment. These results suggest that adenylate cyclase activity is not a reliable marker for plasma membranes from adult rat lungs.

Hepatitis B surface antigen in hepatocytes at necropsy

Seventy cases of cirrhosis and hepatocellular carcinoma (HCC) and 43 cases with no primary liver disease were investigated at necropsy by Gomori's aldehyde fuchsin stain for the presence of hepatitis B surface antigen (HBsAg) in liver cells. The results were correlated with serum HBsAg levels determined by radioimmunoassay and hemagglutination tests performed during the last three months of life or after death. In more than 90% of cases, a correlation was found between the results in tissue and in sera. The aldehyde fuchsin stain is a reliable tool for the detection of HBsAg in patients with cirrhosis and with HCC or without primary liver disease.