Rupture of pectoralis major muscle in an elderly patient receiving long-term hemodialysis: case report and literature review.

Total or near-total rupture of the pectoralis major muscle is rare. It has mainly occurred in male patients between 20 - 40 years of age while performing weight-lifting. Major tendon rupture is a rare but well-documented complication of long-term dialysis. However, rupture of pectoralis major in dialysis patients had never been reported before. Here, we present a pectoralis major rupture in an elderly patient receiving maintenance hemodialysis. Both old age and long-term dialysis could be risk factors of rupture. The clinicians should pay more attention to this complication when taking care of elderly patients on hemodialysis.

Differential expression of neural-cadherin in pulmonary epithelial tumours.

AIMS: Neural (N)-cadherin belongs to a group of transmembrane molecules with a crucial role in tissue morphogenesis and maintenance of an epithelioid phenotype and increased N-cadherin expression is implicated in tumour progression and dedifferentiation. The aim was to determine whether evaluation of N-cadherin in pulmonary tumours might assist in identifying lesions with more aggressive potential. METHODS AND RESULTS: One hundred and fifty-five pulmonary lesions were analysed for N-cadherin expression using immunohistochemistry, including neuroendocrine hyperplasia (n = 3), typical carcinoid (n = 59), atypical carcinoid (n = 12), small cell lung carcinoma (n = 11), large cell neuroendocrine carcinoma (n = 12), adenocarcinoma (n = 35) and squamous cell carcinoma (n = 23). Lymph node status was correlated with immunohistochemical expression. N-cadherin expression was demonstrated in all cases of neuroendocrine hyperplasia, 96% of typical carcinoids, 83% of atypical carcinoids, 63% of the small cell lung carcinomas and 32% of large cell neuroendocrine carcinomas. Over 90% of the adenocarcinomas and 100% of the squamous cell carcinomas were negative. Increased N-cadherin expression in typical carcinoids was associated with negative lymph node status (P < 0.001). DISCUSSION: N-cadherin is differentially expressed in pulmonary tumours and is predominantly observed in neuroendocrine lung lesions with high expression in typical and atypical pulmonary carcinoids. The level of expression of N-cadherin between types of lung tumours does not appear to indicate malignant potential or aggressive behaviour.

The placentas of patients with severe acute respiratory syndrome: a pathophysiological evaluation.

AIMS: The pathology of the placentas delivered from pregnant women who had severe acute respiratory syndrome (SARS) in Hong Kong was studied. METHODS: The pathology of the placentas was retrospectively studied in detail and compared with control sets. The clinical data of the women and neonates were also reviewed. RESULTS: A total of seven placentas were studied. The placentas from two women convalescent from SARS in the first trimester were normal. In three placentas delivered in the acute stage of SARS, there were increases in intervillous or subchorionic fibrin which might be related to disturbances in maternal placental blood flow due to the hypoxic respiratory disease. Extensive fetal thrombotic vasculopathy (FTV) with sharply demarcated zones of avascular fibrotic villi was noted in the placentas of two patients convalescent from SARS in the third trimester. Both pregnancies had intrauterine growth retardation, oligohydramnios and newborns small for gestation. The aetiology of the FTV might be related to thrombotic tendency due to SARS or placental hypoxia. CONCLUSIONS: This report highlights placental pathology that was probably the result of pathophysiological alteration of the maternal fetal unit during SARS. Further studies are required to delineate the relationship between severe maternal respiratory disease, placental pathology and pregnancy outcome.

Intracranial multiple myeloma involving the dura.

Meningeal involvement in multiple myeloma is rare. We report a case in which a patient with a history of multiple myeloma presented with neurological deficit due to meningeal involvement.

BRAF and NRAS mutations are uncommon in melanomas arising in diverse internal organs.

BACKGROUND: Malignant melanoma arising from different body compartments may be associated with differing aetiological factors and clinical behaviour, and may manifest diverse molecular genetic profiles. Although many studies have focused on cutaneous melanoma, little is known of mucosal and other types of melanoma. In particular, malignant melanoma of soft parts is different from other melanomas in many respects, yet manifests a common melanocytic differentiation. Mutation of BRAF is now known to be common in cutaneous melanomas, and raises possible new therapeutic options of anti-RAF treatment for these patients. Few data are available for non-cutaneous melanomas. AIMS: To study the incidence of BRAF and NRAS mutations in melanomas arising in diverse internal organs. METHODS: Fifty one melanomas from various internal organs were investigated for BRAF and NRAS mutation by direct DNA sequencing. RESULTS: BRAF and NRAS mutations were found in two and five mucosal melanomas arising from the aerodigestive and female genital tracts (n = 36). Their occurrence is mutually exclusive, giving a combined mutation incidence rate of 19.4% in mucosal melanomas. Both BRAF and NRAS mutations were absent in malignant melanoma of soft parts (n = 7). BRAF mutation was also absent in uveal melanoma (n = 6), but was seen in two of five cutaneous melanomas. The incidence of BRAF or combined BRAF/NRAS mutations in all non-cutaneous groups was significantly lower than published rates for cutaneous melanomas. CONCLUSION: Each melanoma subtype may have a unique oncogenetic pathway of tumour development, and only a small fraction of non-cutaneous melanomas may benefit from anti-RAF treatment.

Calcium kinetics in the aorta of spontaneously hypertensive rats.

In the search for abnormalities in hypertensive vessels Ca kinetics was studied in the aorta of spontaneously hypertensive rats (SHR). The uptake of 45Ca was significantly less in hypertensive animals but the uptake of 'Lanthanum resistant' 45Ca was not. The efflux of 45Ca from aorta of SHR was different (P less than 0.01) from that of control rats because of faster initial efflux. The half-life of the first 2 components of efflux curves was significantly shorter in SHR. Results are interpreted as consequences of decreased Ca binding by smooth muscle membrane in hypertensive vessels.

Dietary supplementation with n-3 fatty acids from weaning limits brain biochemistry and behavioural changes elicited by prenatal exposure to maternal inflammation in the mouse model.

Prenatal exposure to maternal immune activation (MIA) increases the risk of schizophrenia and autism in the offspring. The MIA rodent model provides a valuable tool to directly test the postnatal consequences of exposure to an early inflammatory insult; and examine novel preventative strategies. Here we tested the hypotheses that behavioural differences in the MIA mouse model are accompanied by in vivo and ex vivo alterations in brain biochemistry; and that these can be prevented by a post-weaning diet enriched with n-3 polyunsaturated fatty acid (PUFA). The viral analogue PolyI:C (POL) or saline (SAL) was administered to pregnant mice on gestation day 9. Half the resulting male offspring (POL=21; SAL=17) were weaned onto a conventional lab diet (n-6 PUFA); half were weaned onto n-3 PUFA-enriched diet. In vivo magnetic resonance spectroscopy measures were acquired prior to behavioural tests; glutamic acid decarboxylase 67 (GAD67) and tyrosine hydroxylase protein levels were measured ex vivo. The main findings were: (i) Adult MIA-exposed mice fed a standard diet had greater N-acetylaspartate/creatine (Cr) and lower myo-inositol/Cr levels in the cingulate cortex in vivo. (ii) The extent of these metabolite differences was correlated with impairment in prepulse inhibition. (iii) MIA-exposed mice on the control diet also had higher levels of anxiety and altered levels of GAD67 ex vivo. (iv) An n-3 PUFA diet prevented all the in vivo and ex vivo effects of MIA observed. Thus, n-3 PUFA dietary enrichment from early life may offer a relatively safe and non-toxic approach to limit the otherwise persistent behavioural and biochemical consequences of prenatal exposure to inflammation. This result may have translational importance.

Bile acid pool size in relation to functional status of gallbladder and biliary lipid composition in Chinese.

Bile acid pool size was measured in 10 Chinese without gallstones, 14 with pigment stones, and 10 with mixed stones by an isotope dilutin technique. Functional status of gallbladder was evaluated by intravenous cholecystogram and its gross appearance at surgery. Biliary lipid composition was also determined. The control subjects had a bile acid pool size comparable to that of Caucasians. Regardless of the nature of gallstones, bile acid pools of stone patients with functioning gallbladder were within normal range, whereas the pools of those with non- or poorly-functioning gallbladder diminished to about two-thirds of the control. Thus, the diminution of bile acid pool size was apparently the consquence of loss of storage function of gallbladder rather than the cause of production of lithogenic bile. The common bile duct bile obtained from stone patients with nonfunctioning gallbladder had a relatively high lithogenic index, at least partly related to its low total lipid concentration.

Histologic changes in the breast after fine-needle aspiration.

Fine-needle aspiration biopsy (FNAB) of the breast has been widely used in many centers worldwide for the initial management of patients with breast lumps. However, little has been written on the morphologic changes secondary to this commonly applied procedure. Thus we performed a retrospective study on 184 consecutive breast-excision specimens with a history of FNAB. Seventeen cases (9.2%) showed changes definitely attributable to the FNAB procedure, including three cases of near total destruction of the lesion as a result of hemorrhage (one case) or infarction (two cases), focal hemosiderin deposition (seven cases), hemorrhage with organization at the periphery (six cases), and a case of ductal papilloma showing a previously undescribed occurrence of benign epithelial implantation. The latter exhibited alarming histologic features simulating invasive carcinoma by virtue of the presence of small narrow tubules with mild cellular atypia haphazardly distributed in the fibrogranulation tissue around the papilloma; the tubules were confirmed to be benign by the presence of muscle-specific actin-positive myoepithelial cells. Other changes were possibly attributable to the FNAB procedure, including linear necrosis in the peripheral portion of the tumor (six cases), intraluminal hemorrhage in fibroadenoma (five cases), and multicentric hemorrhage in the mucinous carcinomas (four cases). We conclude that the rare occurrence of extensive tissue necrosis after FNAB can pose great difficulties in definitive diagnosis of the lesion in the subsequent excision specimen. Other changes are relatively minor, but the occurrence of benign implantation after FNAB may lead to an erroneous diagnosis of invasive carcinoma.

Bone scanning in the early assessment of nasal bone graft viability.

This study examined the role of radionuclide bone scanning in the early assessment of free autologous cancellous bone grafts in augmentation rhinoplasty and compared the failure rates of grafts taken from the calvaria and ilium. Twenty patients had three-phase bone scanning of the facial regions performed between 2 and 15 wk after rhinoplasty, and a comparison was made with the results of clinical assessment and X-ray findings 3 mo after surgery. Eleven patients had grafts taken from the calvaria and nine had iliac grafts. On lateral views, bone graft uptake of isotope, which was less than or equal to the adjacent soft tissue, was found in 2 out of 20 patients and this finding predicted subsequent graft failure as measured by clinical assessment and X-ray evidence of bone resorption. Both failures had grafts taken from the calvaria while none from the ilium failed. These failure rates, however, were not significantly different.

Differentiation of the various stages of Blastocystis hominis by acridine orange staining.

Acridine orange staining differentiates the cystic and the central body forms of Blastocystis hominis and offers a very convenient and easy method to observe the internal structure of the parasite. Acridine orange stains the nuclei and the central body of the rounded vacuolar forms of the parasite bright and dull green, respectively. The colour changes to yellow and then to flaming red-orange when the rounded central body forms of the parasite become cystic.

Tubulovesicular elements in Blastocystis hominis from the caecum of experimentally-infected rats.

By transmission electron microscopy (TEM), tubulovesicular elements were seen in Blastocystis hominis obtained from the caecum of experimentally-infected rats. These appeared to arise from the peripheral cytoplasm and were rounded, oval or elongate in sections. It is suggested that these elements form a network for transfer of nutrients to the periphery during the process of encystation.

Survival of Blastocystis hominis clones after exposure to a cytotoxic monoclonal antibody.

Our previous studies have shown that monoclonal antibodies (MAbs) to Blastocystis hominis react mainly with carbohydrate epitopes, while 1 MAb (1D5) reacts specifically with a protein of 30.5 kDa. In the present study, 3 monoclonal antibodies (1D5, 1E7 and 4F7) were used in immunogold localization. 1E7 and 4F7 were found to react primarily with the surface coat, while 1D5 was plasma membrane-specific. In the presence of complement, only 1D5 exhibited a cytotoxic effect on B. hominis whereas 1E7 and 4F7 did not, suggesting that the surface coat of B. hominis could serve as an immunological barrier against host antibodies. Using a recently described agar plating method, only 1D5 exhibited significant (P < 0.01) complement-independent cytotoxicity to B. hominis, inhibiting colony growth at low concentrations. Parasites that had been exposed to 1D5 were morphologically smaller than those that were not exposed to this MAb. Colonies that grew in the presence of 1D5 were isolated and grown in liquid medium containing increasing amounts of the cytotoxic MAb. Two clones that grew well in liquid medium containing 1D5 were also able to develop into colonies in soft agar. This study has shown that the 30.5 kDa protein found on the plasma membrane of B. hominis is a functionally important protein and that not all cells within a certain population would be susceptible to the cytotoxic effects of 1D5. These findings suggest that a heterogenous population exists in continuously maintained cultures of B. hominis.

Production and characterization of murine monoclonal antibodies to Blastocystis hominis.

Several hybridomas producing antibodies detected by enzyme-linked immunosorbent assay (ELISA) were established by fusions of mouse myeloma P3.X63.Ag8.U1 with spleen cells from BALB/c mice immunized against an isolate of Blastocystis hominis. Five strongly positive hybrids (6B6, 1D5, 1E7, 4F7 and 4G11) were cloned and all were found to secrete IgM monoclonal antibodies. Four MAbs (6B6, 1E7, 4F7 and 4G11) reacted in immunoblots with a number of B. hominis antigens (mol. wt ranging from 25,000 to 220,000) which were likely to be repeating oligosaccharide epitopes located on glycoproteins, as indicated by pronase and periodate treatment. Another MAb (1D5) reacted with a single antigenic band (mol. wt 30,5000). Similar results were obtained in immunoblots using 4 other B. hominis isolates. Indirect fluorescent-antibody assay (IFA) using MAbs showed 3 patterns of reactivity. 1D5 showed patchy fluorescence, 4F7 showed peripheral fluorescence and 6B6, 1E7 and 4G11 showed bright diffuse fluorescence. These patterns were observed for all 5 human Blastocystis isolates. The MAbs exhibited some cross-reactivity with 2 reptilian Blastocystis isolates but not with Giardia intestinalis, Trichomonas vaginalis or Entamoeba histolytica.

Evaluation of the common conditions associated with eosinophilia.

In an eosinophilic population of 47 boys of the same age, a large proportion (92%) were helminth infested or atopic, or both, compared with 36% of 36 controls. The methods used to detect these conditions were not costly or elaborate, except for the radioallergosorbent test, which was used to measure concentrations of circulating IgE antibodies to atopic allergens. It is suggested that an economical approach to detect helminthiasis and atopy in cases of eosinophilia is adopted using the methods employed here, with skin prick tests replacing the radioallergosorbent test.

An ISFET-based immunosensor for the detection of beta-Bungarotoxin.

An ion-sensitive field effect transistor (ISFET)-based immunosensor was developed to detect/quantitate beta-Bungarotoxin (beta-BuTx), a potent presynaptic neurotoxin from the venom of Bungarus multicinctus. A murine monoclonal antibody (mAb 15) specific to beta-BuTx was immobilized onto silicon nitride wafers after silanization and activation with glutaraldehyde. A chip based enzyme linked-immunosorbantassay (ELISA) was performed to ascertain antigen binding to the immobilized antibody. To develop an electrochemical immunosensing system for the detection/quantitation of beta-BuTx, an ISFET was used as a solid phase detector. MAb 15 was immobilized on the gate region of the ISFET. The antigen antibody reaction was monitored by the addition of urease conjugated rabbit anti-beta-BuTx antibodies. The sensor can detect toxin level as low as 15.6 ng/ml. The efficacy of the sensor for the determination of beta-BuTx from B. multicinctus venom was demonstrated in mouse model. Toxin concentration was highest at the site of injection (748.0+/-26 ng/ml) and moderate amount was found in the plasma (158.5+/-13 ng/ml).

Well-differentiated papillary adenocarcinoma arising in a supratentorial enterogenous cyst: case report.

OBJECTIVE AND IMPORTANCE: We report a case of a well-differentiated papillary adenocarcinoma arising in an supratentorial enterogenous cyst. The clinicopathological features of this case and a brief review of the literature are presented. CLINICAL PRESENTATION: A 45-year-old woman presented with abrupt onset of sensory seizures and abnormal sensation on the left side of her face, left leg, and left arm. Radiological studies showed a cystic extraaxial tumor with mass effect in the right parietal area. The initial clinical impression was a metastatic lesion, and a comprehensive metastatic workup revealed no evidence of tumor elsewhere. INTERVENTION: A gross total resection of the solid cystic tumor was achieved by a frontoparietal craniotomy. Sixteen months after the initial surgery, the patient presented with signs of increased intracranial pressure and a large parietal cyst. The cyst was fenestrated at the time of the second craniotomy. CONCLUSION: A pathological study of the initial surgical material revealed it to be a well-differentiated papillary adenocarcinoma in association with an enterogenous cyst. The second surgical specimen consisted only of the benign cyst wall. The patient recovered uneventfully from the second surgery and was free of symptoms 6 months postoperatively. The importance of recognizing the rare possibility of malignant progression of a benign enterogenous cyst in the central nervous system is discussed.

Complexation of copper(I) by thioamino acids. Implications for copper speciation in blood plasma.

There is mounting evidence that Cu(I) is the most important oxidation state of copper in many physiological systems. Research into Cu(I)-thioamino acid complex formation serves not only to improve the chelation therapy for treating copper intoxication but may also provide a better understanding of many facets of normal copper metabolism. Formation constants for the ternary mixed ligand complexes of Cu(I) with cysteine (Cys), glutathione (GSH) and penicillamine (Pen) are reported here for the first time. Potentiometric titrations, using techniques specially developed for the stabilization of aqueous Cu(I), were performed at 25 degrees C in 1.00 M (Na)Cl. It was found that precipitation severely limits the experimentally accessible pH range and, consequently, the computer analysis of the binary metal-ligand systems; however, it is also found that this is less of a problem when two different ligands are present. This latter fact permitted better models of the binary systems to be developed. The formation constants of Cu(I)-thioamino acids determined in this work were used in an improved computer simulation of copper speciation in blood plasma which, for the first time, incorporates redox equilibria.

Hepatocellular carcinoma metastasizing to the brain and orbit: report of three cases.

Hepatocellular carcinoma rarely metastasizes to the brain or orbit. We report 3 clinically manifest examples, one of which occurred in a 13-yr-old boy. In 2 cases the intracranial metastasis was the initial presenting lesion. The 2 cases of brain metastasis both presented with intracerebral hemorrhage. Light microscopic examination of these tumors revealed a trabecular hepatocellular carcinoma of Edmondson grade II with focal hemorrhage and necrosis. Their immunohistochemical profile was identical to that described for primary hepatocellular carcinoma. The differential diagnosis from other intracranial metastatic tumors is discussed.

Sex selection in practice among Hong Kong Chinese.

The aim of this study is to identify factor(s) influencing imbalance in the sex distribution of children (more children of the same sex) of the multiparous women attending an antenatal clinic in Hong Kong. A retrospective study was carried out to compare the expected and observed sex ratios of babies born to women with one previous live birth and women with two. All singleton pregnant women of parities 1 and 2 delivering after 22 weeks of gestation, between 1 July 1996 and 30 June 1998, were included. A total of 2604 women of parity 1 and 752 women of parity 2 were included. The sexes of the children of parity 1 women and the sex distribution of their newborns were consistent with the predicted value. The parity 2 women were more likely to have third children if their previous children were of the same sex (p-value < 0.001). This implies that the parity 2 women attending our antenatal clinic had third pregnancies because of social, economical or environmental reasons. Our parity 2 women with two daughters were more likely to have sons (p < 0.05). Thus, biological or parental factors were unlikely to be important in influencing the sex of the newborn. This suggested that sex selection or sex-selective abortion might be practiced among Hong Kong Chinese women.