Multiple giant duodenal gallstones causing gastric outlet obstruction: Bouveret's minefield revisited

Gastric outlet obstruction caused by a gallstone impacted in the duodenum is a rare entity known as Bouveret's syndrome. We report the unusual case of multiple large gallstones impacted in the duodenum from a cholecystoduodenal fistula in an 83-year-old lady. A high index of suspicion allowed for prompt diagnosis. Early surgical intervention was instituted because if the size and number of gallstones with an excellent outcome. The surgical strategies and underlying pitfalls underlying the management of this syndrome are critically reviewed and discussed.

Founder mutation in the BRCA1 gene in Malay breast cancer patients from Singapore

The mutation spectrum of the BRCA1 gene among ethnic groups from Asia has not been well studied. We investigated the frequency of mutations in the BRCA1 gene among Malay breast cancer patients from Singapore, independent of family history. By using the protein truncation test (PTT) and direct sequencing, BRCA1 mutations were detected in 6 of 49 (12.2%) unrelated patients. Four novel missense mutations in exon 11, T557A (1788A>G), T582A (1863A>G), N656S (2086A>G) and P684S (2169C>T) were identified in one patient. Two patients had missense mutations in exon 23, V1809A (5545T>C), which has been previously detected in individuals from Central and Eastern Europe. Three unrelated patients had the deleterious 2846insA frameshift mutation in exon 11. Methylation specific PCR (MSP) of the promoter region of the BRCA1 gene detected hypermethylation of tumor DNA in an additional 2 patients. Haplotype analysis using the microsatellite markers D17S855, D17S1323 and D17S1325 revealed a common haplotype for the three unrelated patients and their three relatives with the 2846insA mutation. These findings strongly suggest that the 2846insA mutation, the most common deleterious mutation in this study, may possibly be a founder mutation in breast cancer patients of Malay ethnic background.

Single institution's initial experience with sentinel lymph node biopsy in breast cancer patients

BACKGROUND

The sentinel lymph node is the first draining node from a cancer-bearing area and is therefore the first to manifest metastasis. In breast cancer it has been shown to predict the axillary status. Axillary dissection provides information determining prognosis and need for adjuvant therapy but carries a certain morbidity. Our aim was to determine the feasibility of detecting the sentinel node in a teaching hospital and whether the sentinel node accurately predicts the axillary status.

METHODS

All patients with stage I and II breast cancer and non-palpable axillary nodes were eligible, including those with previous excision biopsy. We excluded pregnant women, those with previous axillary surgery and women with advanced breast cancer with enlarged axillary nodes. The sentinel node was detected with technetium-99m-labelled tin colloid and vital blue dye and removed, and axillary clearance was performed.

RESULTS

A total of 312 patients were examined from August 1996 to December 1998. The mean age was 53 years (range 28-83) and mean tumour size 2.6 cm (range 0.2-9.0). The detection rate of the sentinel node was 86%. The sentinel lymph node predicted the axillary status with a sensitivity of 83% and specificity of 100%. The false-negative rate was 16.7%.

CONCLUSIONS

Detection of the sentinel lymph node is feasible and it can accurately predict the nodal status of the axilla. However, the high false-negative rate precludes as yet the use of sentinel lymph node biopsy in replacing axillary clearance as the standard of care for breast cancer.

All that wheezes is not asthma

Asthma is a common disease. Wheezing is not pathognomonic of asthma, however. One must be alert when appropriate asthmatic treatment does not provide adequate control. Other causes of airway obstruction must be considered, especially when stridor is heard. This report describes an elderly patient who had been managed as having asthma but had an endotracheal tumour.

Cost-effectiveness of CT thorax and bronchoscopy in haemoptysis with normal CXR for exclusion of lung cancer

As fibre-optic bronchoscopy and CT thorax become more widely used, patients with haemoptysis who had normal CXR and sputum results are more commonly offered both CT and bronchoscopy to exclude lung cancer. Doctors who are under possible litigation pressure arising from missed diagnoses of lung cancer are often exhaustive in their investigations, even when the haemoptysis has been transient. The present study aims to investigate the number of cancer patients who can be detected with the two investigations, and compare recent similar study results with archive results. We found that despite the use of more efficient investigation tools, the yield is paradoxically much lower and, hence, less cost-effective than that of previous studies. The likely reason is that doctors tend to over-investigate, even for short-term, minimal blood-streaked sputum, which is common among simple bronchitis. In order to be more cost-effective, these investigations should be used more selectively and for high risk patients such as those with prolonged haemoptysis and those who are heavy smokers.

Changing patterns of strabismus: a decade of experience in Hong Kong

BACKGROUND/AIMS

Racial variation in the pattern of strabismus is known, but few large scale studies on non-white populations are available. Furthermore, longitudinal change in this pattern within a local setting has not been well documented in the past. This study aims to support the clinical impression that exotropia is more common in Chinese patients, and that the proportion of patients with exotropia has been increasing in the past decade.

METHODS

A total of 2704 consecutive patients with the diagnosis of primary horizontal strabismus, seen in the strabismus clinic of the Hong Kong Eye Hospital, were retrospectively analysed to determine the relative prevalence of esotropia and exotropia. Characteristics recorded include patient demographics, type of strabismus, and whether the nature of the squint was constant or intermittent.

RESULTS

742 (27.4%) patients were found to have esotropia, 548 (20.3%) had constant exotropia, 1213 (44.9%) had intermittent exotropia, and 201 (7.4%) had microtropia. The proportion of exotropic to esotropic patients was shown to increase steadily throughout the past decade (p<0.0001). This was mainly accounted for by an increase in the number of patients with intermittent exotropia, and a corresponding decrease in the number of patients with esotropia.

CONCLUSION

Exotropia was shown to be more prevalent than esotropia in a Hong Kong Chinese population. Furthermore, the proportion of patients with intermittent exotropia appears to be increasing, in contrast with esotropic patients. The exact nature of this trend, and possible aetiological factors will require further study.

A study on the prevalence of and risk factors for neck pain among university academic staff in Hong Kong

The 1-year prevalence of neck pain and possible risk factors among university academic staff were investigated. Self-administered questionnaires were distributed to all the full-time academic staff in one of the universities in Hong Kong. The 1-year prevalence of neck pain was investigated. The relationship between individual factors, job nature, psychosocial factors, and neck pain were also analyzed. The 1-year prevalence of neck pain among after being an academic staff was 46.7%. A significant association was found between gender and neck pain (p = 0.02). The percentage of female academic staff with neck pain (62%) was higher than that in male staff (38%). This matched the results of other studies, which demonstrated that neck pain was more prevalent in women. There was a significant association between head posture during computer processing and neck pain (p = 0.02). Among those with neck pain during computer processing, 60.5% had a forward head posture. However, a low correlation between psychosocial factors and neck pain was demonstrated (r = 0.343). Academic staff in tertiary institutions could be considered as a high-risk group of job-related neck pain.

Breast abscess as the initial presentation of squamous cell carcinoma of the breast

Breast abscesses are common and rarely harbour an underlying malignancy. Antibiotics and drainage by aspiration are the mainstays of treatment. We encountered two post-menopausal patients aged 48 and 70 who presented with acute breast abscesses that had an underlying squamous cell carcinoma of the breast. Infective aetiology was considered in each case and pre-operative diagnosis is possible but requires a high level of suspicion to avoid a delay in diagnosis. Aspirate from the abscess should be sent for both culture and cytology and if drainage is done, then biopsy of the abscess cavity is essential. Clinicians should be aware of the association of this rare primary neoplasm of the breast.

Patterns of abnormal FDG uptake by various histological types of non-small cell lung cancer at initial staging by PET

The aim of this study was to identify useful patterns of abnormal fluorine-18 fluorodeoxyglucose (FDG) uptake by different types of non-small cell (NSC) lung cancer and to assess their clinical implications. One hundred and three sequential patients with newly diagnosed, pathology-proven NSC lung cancer were included. FDG positron emission tomography (PET) images were acquired using a dedicated PET scanner. There were 35 squamous cell carcinomas (SQC), 17 large cell cancers (LGC), 38 adenocarcinomas (ADC), 1 bronchioloalveolar carcinoma (BAC) and 12 non-classified NSC cancers. PET images were categorized into detectable patterns of necrotic center in the primary tumor, satellite lesions (T4), hilar lymph nodes (N1), and N2, N3, and M1 lesions by visual interpretation of PET images for SQC, LGC, and ADC (n=90; BAC and non-classified NSC cancers were excluded). The PET lesions were correlated with surgical pathology and with CT findings in inoperable cases. Necrosis was more commonly present in the primary tumors of LGC (53%) and SQC (43%) than in those of ADC (26%) (P<0.0001 and <0.01, respectively). The frequencies of nodal uptake in ADC, SQC and LGC were similar (71%, 60%, and 59%, respectively). However, M1 lesions were present significantly more often in LGC (41%) and ADC (34%) than in SQC (3%) (both P<0.0001). Significantly more surgically inoperable cases were found by PET (T4, N3, M1) in ADC (50%) and LGC (41%) than in SQC (26%) (P<0.001 and <0.02, respectively). Our results suggest a wide variation of PET findings for different types of NSC lung cancer. Identification of these patterns is useful in clinical PET interpretation, in that knowledge of the most probable association between the PET patterns and the histological types will facilitate initial staging and planning of management.

Gender-related psychosocial and cultural factors associated with condom use among Chinese married women

The present study explored the interplay of psychosocial, gender, and cultural factors on Chinese married women's condom use. A total of 433 Chinese married women residing in Hong Kong participated in the study. Correlation results showed that participants' conservative gender attitudes toward sexuality and sexual decision making were related to less accurate HIV/AIDS knowledge and less concern about contacting the disease from their husbands. About 34.4% of the sexually active participants never used condoms in the past 6 months, and current condom use was associated with egalitarian gender attitudes, positive feelings about condom use, and concerns about contacting HIV/AIDS from their husbands. Among all participants, 32.5% reported that they would not use condoms in their future sexual encounters. Future condom use was related to shorter duration of marriage, accurate HIV/AIDS knowledge, egalitarian gender attitudes, current condom use, and positive feelings about condom use. Results from the logistic regression analyses showed that egalitarian gender attitudes toward sexuality and positive feelings about condom use were the most salient predictors for current and future condom use.

Treating pulmonary TB. Revisiting an old problem

BACKGROUND

There is a resurgence of pulmonary tuberculosis worldwide, due to increase in air travel, decrease in resources in health control, as well as the AIDS pandemic. As pulmonary tuberculosis was not common in Australia, family physicians are facing a new challenge. The following is to highlight some principles in tuberculosis treatment.

OBJECTIVE

This article revisits some of the basic principles of treatment of tuberculosis in order to maximise management.

DISCUSSION

The tubercle bacillus has been capable of developing resistance to antituberculosis drugs for some time, making multiple drug therapy mandatory. Antituberculosis drugs on the other hand can be toxic and commonly cause gastro-intestinal upset. The patient has to take many tablets a day for many months. By informing patients of the side effects, compliance, which is the key issue to successful therapy, is enhanced.

Soluble E-cadherin is a valid prognostic marker in gastric carcinoma

BACKGROUND

Gastric cancer remains a major cause of cancer mortality globally but no good prognostic tumour marker is available. Soluble fragment of E-cadherin protein has been reported to increase in the sera of patients with cancer and recently was found to be elevated in 67% of patients with gastric cancer.

AIMS

To investigate if serum soluble E-cadherin is a valid prognostic marker in gastric cancer.

METHODS

Concentrations of soluble E-cadherin from 116 patients with histologically confirmed gastric adenocarcinoma and 40 healthy subjects were measured using an immunoenzymometric method with a commercially available sandwich ELISA kit based on monoclonal antibodies.

RESULTS

The logarithm of the means of soluble E-cadherin concentration was significantly higher in patients with gastric cancers (mean 3.85 (SD 0.28)) than in healthy subjects (3.71 (0.18)) (p=0.001), and in palliative/conservatively treated cancers (3.91 (0.35)) than in operable cancers (3.78 (0.19)) (p=0.015). The logarithm of the concentrations correlated with tumour size (p=0.032) and carcinoembryonic antigen concentrations (p=0.001). The cut off value calculated from discriminant analysis on operability and inoperability/palliative treatment was 7025 ng/ml. Soluble E-cadherin concentrations higher than this cut off value predicted tumour (T4) depth invasion (p=0.020, confidence interval (CI) 1.008-1.668) and palliative/conservative treatment (p=0.023, CI 1.038-2.514). In contrast, the relative risks for lymph node (N2) metastasis, distant metastasis, and stage III/IV disease were 1.41, 1.33, and 1.55 respectively, despite not reaching statistical significance.

CONCLUSION

Serum soluble E-cadherin is a potential valid prognostic marker for gastric cancer. A high concentration predicts palliative/conservative treatment and T4 invasion.

Pulmonary haemorrhage in a patient with Kikuchi disease

Kikuchi disease is an immunologic disease and most commonly presents with cervical lymphadenopathy. It is usually self-limiting [1]. It is sometimes associated with systemic lupus erythematosus (SLE) [2], and can be associated with many complications including aseptic meningitis, neuropathy, brachial neuritis. It can also be associated with lymphoma, and may sometimes be misdiagnosed as such [3]. The following is the first reported case of Kikuchi disease associated with pulmonary haemorrhage. The patient died and no other cause of the pulmonary haemorrhage could be identified at post mortem.

Surgical treatment of tibial plateau fracture in elderly patients

This retrospective study involves 22 patients with displaced tibial plateau fractures who were treated surgically from July 1993 to April 1996. All the patients were over 60 years old (mean 66.3 years old, range 61-80 years). All of the patients were treated by open reduction and internal fixation with AO/ASIF buttress plates (Synthes, Bochum, Switzerland). Additional small fragment plate or inter-fragmental screws were used in some of them as indicated. Two patients died during follow-up of causes unrelated to the fractures. The average follow-up time was 49.8 months (range 36-68 months). The other 20 patients were interviewed at the outpatient clinic, and radiographs of bilateral standing knees were taken. By comparison with the uninjured side on radiographs, condylar joint space depression was noted in 6 patients. However, joint depression greater than 4 mm was not found. Malalignment with varus or valgus greater than 5 deg was not demonstrated in any case. Their range of motion was restored in all patients, with more than 120 deg of flexion and without extension lag except for the one who suffered a superficial wound infection. No complication required further surgical management. During the period of follow-up, no accelerated degenerative change in the operated knee joint resulted in total knee arthroplasty. Two patients needed occasional medical treatment for residual knee joint pain. Only two patients needed canes for assistance during walking due to old age and minor stroke. The results justify surgical treatment for displaced tibial plateau fractures in elderly patients.

Effects of knee joint angles and fatigue on the neuromuscular control of vastus medialis oblique and vastus lateralis muscle in humans

The effects of different knee joint angles and fatigue on the neuromuscular control of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles were investigated in 17 (11 men, 6 women) young subjects. The electromyogram (EMG) activities and the force generation capacities were monitored before and after a fatigue protocol at three different knee joint angles, 90 degrees, 150 degrees, 175 degrees of knee extension, on three occasions. In response to randomly triggered light signals, the subjects performed three isometric maximal voluntary contraction (IMVC) that lasted for 4 to 8 s. This was then followed by the fatigue protocol which consisted of six bursts of contractions fixed at 30 s on and 10 s off. Immediately after the exercise to fatigue, the subjects performed another three IMVC in response to the light signals. Repeated measures ANOVA were performed to examine the effects of fatigue at these three positions on the electromechanical delay (EMD), median frequency (fmed), peak force (Fpeak) and root mean square (rms)-EMG:Fpeak quotient of VMO and VL. The results revealed a significant effect of the three knee joint angles on the EMD before the fatigue (P < 0.05). The fatigue protocol induced a significant decrease in Fpeak at all the three positions (P < 0.01). However, the fatigue induced a significant decrease of fmed at only 90 degrees and 150 degrees of knee extension (P < 0.01). This occurred in parallel with the lengthening of EMD at these two joint angles (P < 0.01 and P < 0.05). The effects of fatigue on the fmed and EMD were not significant between VMO and VL at all three angles. The insignificant difference in fmed and EMD between VMO and VL at the three knee positions before and after fatigue indicated that no preferential onset activation between VMO and VL had occurred.

Comparison of myocardial oxygen consumption using 11C acetate positron emission tomography scanning in a working and non-working heart transplant model

OBJECTIVE

In acute cardiac rejection, changes in myocardial oxygen consumption occur; non-invasive detection of these metabolic changes would have obvious clinical utility. In the classic cervical, heterotopic, canine, transplant model, the heart is non-working. It has a low myocardial oxygen consumption. Creation of a working model with normal myocardial oxygen consumption would enhance validity of non-human studies.

METHODS

Clearance of 11C acetate was determined by positron emission tomography (PET) scanning and compared with myocardial oxygen consumption in normal and transplanted canine hearts. Donor hearts from mongrel dogs (2.5-3 kg; n=4) were transplanted into the neck of adult beagles (12-15 kg; n=4), no immunosuppression was given. Two non-working hearts were modified to eject only coronary flow via the right ventricle. In two hearts, a novel working model was created with aortic regurgitation to load the left ventricle. Working and non-working hearts underwent PET scanning on post-operative days 2 and 4. Normal dog hearts (n=2) and native hearts of transplanted dogs (n=3) were used to validate the scanning technique. Coronary sinus and aortic oxygen saturation data along with myocardial blood flow (radiolabeled microspheres) confirmed that clearance of 11C acetate in normal and transplanted hearts followed a bi-exponential model.

RESULTS

Myocardial oxygen consumption was correlated with the rate constant of 11C acetate rapid phase clearance (r=0.91) in normal and transplanted hearts. The working hearts had increased myocardial oxygen consumption compared to non-working hearts.

CONCLUSIONS

This study (1) introduces a model of a working heterotopic cardiac transplantation with near-normal oxygen consumption; and (2) demonstrates that regional myocardial oxygen consumption in transplanted hearts can be detected by 11C acetate PET.

Impact of inadequate fine-needle aspiration cytology on outcome of patients with palpable breast lesions

BACKGROUND

The purpose of the present study was to assess the impact of inadequate fine-needle aspiration cytology (FNAC) breast specimens on the outcome of patients with a palpable breast lesion.

METHODS

A retrospective review was carried out of inadequate FNAC specimens from the Department of General Surgery, Singapore General Hospital in 1997.

RESULTS

One hundred and thirty-eight (16.6%) of 831 FNAC specimens were reported inadequate, and these form the study group. Outcome analysis was divided into benign on excision biopsy (n = 38; 29.4%); benign on repeat FNAC or trucut biopsy (n = 6; 4.7%); benign on follow up (n = 46; 35.7%); malignant on histology (n = 11; 8.5%); and lost to follow up (n = 28; 21.7%). The 11 cases with breast cancer were further analysed. The mean time to treatment was 88.3 days for three patients whose tumours were not clinically suspicious of malignancy versus 20 days for six patients who were diagnosed with cancer clinically from the onset. One patient with cancer refused treatment and one absconded from treatment only to return 7 months later.

CONCLUSION

Breast cancer was present in 8.5% of the inadequate FNAC specimens. When clinical suspicion of malignancy is high, an excision biopsy is advised in patients with inadequate FNAC specimens. If properly managed with triple tests and good clinical judgement, the inadequate FNAC specimens do not delay treatment in patients with breast cancer.

Microdochectomy for single-duct nipple discharge

INTRODUCTION

Isolated single-duct nipple discharge is worrying and poses a surgical dilemma. Factors predicting malignancy are controversial.

MATERIALS AND METHODS

Retrospective review of 92 consecutive microdochectomies for single-duct nipple discharge in a tertiary referral centre over 8 years.

RESULTS

The commonest causes were ductal papilloma (52%) and fibrocystic diseases of the breast (21%). Five (5%) patients had breast carcinoma, of whom only 1 had an invasive component. The median age of these patients was 43 years (range 26 to 72 years) which was similar to median age of the whole cohort. Sixty-seven (73%) patients presented with blood-stained nipple discharge. The 5 patients with breast carcinoma had blood-stained discharge. Mammography was abnormal in 1 out of 4 patients in the carcinoma group.

CONCLUSIONS

The incidence of breast carcinoma in patients presenting with isolated single-duct nipple discharge was low (5%) among Singaporean women. There was no reliable predictors of malignancy, though all patients with carcinoma presented with blood-stained discharge. Microdochectomy still remains an effective treatment for nipple discharge both for cure and diagnosis.

Serotonin infusion in the SCN reduces casein ingestion in rats

To compare food and water intakes, adult male Wistar rats were infused during 7 days with serotonin (5-HT, 2.5 nmol/24 h) or artificial cerebrospinal fluid (CSF) in the suprachiasmatic nucleus (SCN) in a three-way selection of macronutrient-rich diets. Nocturnal energy intake from the casein-rich diet was significantly lower during infusion of 5-HT than before infusion. Decrease in nocturnal casein consumption was significant in the middle dark phase. Within the infusion period, water intake was reduced by 5-HT infusion during the early, middle and late light phase. The present results reinforce the hypothesis of a serotonergic control of water intake and provide evidence for SCN 5-HT involvement in casein-specific dietary selection.

Focused abdominal sonography for trauma (FAST)

This study aims to examine the feasibility of applying the focused ultrasound examination (FAST) in the initial assessment of the trauma patient. Its advantage over diagnostic peritoneal lavage lies in the speed in which it can be performed, its non-invasiveness and repeatability. Over the period January 1997 to July 1998, the FAST examination (Acuson 128XP/10, 3.5 MHz probe) was used to assess the presence of haemopericardium or haemoperitoneum in 38 multi-trauma patients admitted to the Singapore General Hospital. The sample comprises mainly males (82%) with a mean age of 34 years (range 17 to 77 years). The mechanism of injury was predominantly blunt (95%). Mean Injury Severity Score (ISS) was 22. Eleven patients presented in shock and 16 patients had abdominal tenderness on examination. A single surgeon did the examination, which was performed during the secondary survey phase of resuscitation. Time taken for the FAST examination averaged 2.3 +/- 1.3 minutes. The results of the examination were compared to diagnostic peritoneal lavage, CT scan, operative findings, serial examination and/or post-mortem findings. Overall sensitivity was 67% and specificity 97%. Although the FAST examination missed the small amount of free fluid seen in the CT scan of 2 patients, these patients did not have to undergo laparotomy as their abdominal examination was normal. We conclude that the FAST examination is feasible and should be part of a general surgeon's armamentarium in the initial assessment of trauma.

Percutaneous transport of diclofenac sodium from mixtures of fatty alcohol (or fatty acid) and propylene glycol through the rabbit abdominal skin

Diclofenac sodium is a nonsteroidal anti-inflammatory drug with analgesic, antipyretic, and anti-inflammatory activity. When used in a topical application, diclofenac can diffuse through the skin and into the subcutaneous tissue to effect the anti-inflammatory action. In this study, in vitro evaluations of the percutaneous transport of diclofenac sodium in various bases containing fatty alcohols/propylene glycol or fatty acid/propylene glycol mixtures through the abdominal skin of the rabbit were investigated. Results show that the transdermal flux of diclofenac sodium in the fatty alcohol/propylene glycol bases of the same ratio is affected by the chain length of the fatty alcohol, and its effect is in the order of C10 > C12 > C14 > C18. However, the transdermal flux of diclofenac sodium in the fatty acid/propylene glycol bases of the same ratio is also affected by the chain length of the fatty acid, but no absolute relationship was found. For the same chain length of fatty acid and fatty alcohol used in the formulation base that was otherwise the same, the transdermal flux of diclofenac sodium is higher in the formula containing fatty alcohol than that containing fatty acid.

A comparison of trucut biopsy with fine needle aspiration cytology in the diagnosis of breast cancer

INTRODUCTION

Carcinoma of the breast is common in Singapore and many patients may present with just a suspicious breast lump.

AIM

To determine the accuracy of fine needle aspiration cytology (FNAC) and trucut biopsy in the diagnosis of suspicious breast lumps in an outpatient setting.

METHODS

A total of 39 women, from May 1995 to November 1995, who had a suspicious breast lump were subjected to concurrent FNAC and trucut biopsy.

RESULTS

The accuracy of FNAC is 90% whereas trucut biopsy is 67%, the difference being statistically significant with a p < 0.02.

CONCLUSION

FNAC is recommended for the diagnosis of suspicious breast lumps.

Distribution of two hemolytic toxin genes in clinical and environmental isolates of Aeromonas spp.: correlation with virulence in a suckling mouse model

Previous studies have shown that two hemolytic toxins, HlyA and AerA, contribute to the virulence of Aeromonas hydrophila. A survey was performed to gauge the distribution of hlyA and aerA genes in clinical and environmental Aeromonas isolates. For A. hydrophila, A. veronii biotype sobria and A caviae, 96%, 12% and 35% of strains, respectively, were hlyA positive, whereas, 78%, 97%, 41%, respectively, were aerA positive. All virulent A. hydrophila isolates were hlyA+ aerA+. This genotype was most common in A. hydrophila (75.4%) followed by A. caviae (29.4%) and A. veronii biotype sobria (9.6%). For A. hydrophila, a two-hemolytic toxin model of virulence provides the best prediction of virulence in an animal model.

Cerebral perfusion and vascular reserve in fibromuscular dysplasia of the internal carotid artery

We report of a case of abnormal cerebral perfusion but normal vascular reserve by single-photon emission computed tomographic imaging in a 65-year-old woman with fibromuscular dysplasia of the internal carotid artery (ICA). The patient had an aneurysm in her left ICA at the level of second cervical vertebra without evidence of stenosis and was excised with primary anastomosis 3 years ago when she presented with months of dizziness. But follow-up angiography showed high-grade long segmental stenosis in her left ICA, characteristic of fibromuscular dysplasia. Because she was asymptomatic with normal vascular reserve, she was treated medically. This report suggests the usefulness of functional imaging in fibromuscular dysplasia. The potential improvement of cerebral perfusion in this rare disease with acetazolamide or dipyridamole is worthy of further clinical investigation.

The effect of a pressure garment on post-surgical drainage and seroma formation in breast cancer patients

BACKGROUND

The treatment of choice for cancer of the breast are mastectomy and axillary clearance or wide excision with axillary clearance. The most common complication following such a procedure is seroma formation. Various methods have been used to prevent it. However, the use of a pressure garment in this context has not been fully evaluated in the current literature.

RESULTS

In a randomised trial comparing patients with a pressure garment with those without one, we have found no improvement in post-operative drainage with the use of a pressure garment. There were more complications in the group without the pressure garment (19%) compared with those with the garment (15.7%). The only seroma occurred in those patients not using the garment. The use of the pressure garment appeared to increase the duration of use of the drain (6.8 vs 6.1 days), these differences in the two groups was not significant. One of the patients in the pressure garment group was unable to tolerate the warmth and discontinued wearing the garment in the third post-operative day. This gave a rejection rate of 5%.

CONCLUSION

The use of a pressure garment does not reduce the post-operative drainage, however, the complication rate appears to be higher when the pressure garment is not being used.

Incorporation of tryptophan analogues into staphylococcal nuclease: stability toward thermal and guanidine-HCl induced unfolding

The tryptophan analogues, 5-hydroxytryptophan, 7-azatryptophan, 4-fluorotryptophan, 5-fluorotryptophan, and 6-fluorotryptophan, have been biosynthetically incorporated into Staphylococcal nuclease, its V66W mutant, and the Delta 137-149 fragment of the latter mutant. The guanidine-HCl induced unfolding and thermal unfolding of these proteins were studied to characterize the effect of incorporation of these tryptophan analogues on the thermodynamic stability of the proteins. The three proteins have tryptophan residues at positions 140 (in wild type) and 66 (in the Delta 137-149 fragment of V66W) and at both positions (in V66W). The unfolding data show that 5-hydroxytryptophan does not perturb the stability of wild-type nuclease, but it destabilizes the fragment and causes the V66W mutant to unfold in a more cooperative manner. 7-Azatryptophan is found to destabilize all three proteins. 4-Fluorotryptophan is slightly stabilizing of the three proteins, but the other two fluorotryptophans do not alter the stability of the proteins.

Phosphorescence and optically detected magnetic resonance characterization of the environments of tryptophan analogues in staphylococcal nuclease, its V66W mutant, and Delta 137-149 fragment

Phosphorescence and optically detected magnetic resonance (ODMR) measurements are reported on the triplet states of the tryptophan analogues, 7-azatryptophan (7AW), 5-hydroxytryptophan (5HW), and 4-, 5-, and 6-fluorotryptophan (4FW, 5FW, 6FW), when incorporated at position 140 of wild-type Staphylococcal nuclease (7AW-nuclease, etc. ), positions 66 and 140 of its V66W mutant (7AW-V66W, etc.), and the deletion fragment of the latter, Delta 137-149 (7AW-V66W', etc.). These measurements point to the retention of protein structure at position 140 in each of the wild-type nuclease analogues. Substitution of the analogue at both tryptophan sites of V66W leads to structured sites with differentiated triplet-state properties for all analogues except 7AW-V66W, whose structure is destabilized. 5HW-V66W' is the only fragment that apparently lacks structure at position 66. All other V66W' analogues exhibit a structured environment at position 66 (4FW-V66W' was not studied), but in each case this site can be differentiated readily from the corresponding site in intact V66W. 7AW-V66W' is resolved by ODMR into two discrete structures with slightly differing zero field splittings (ZFS). Interaction of the protein with 5HW at position 66 of 5HW-V66W induces a 2-fold increase in the ZFS E parameter, which is reduced to its normal value upon formation of the fragment, 5HW-V66W'. Analogous effects occur for 5FW, but on a smaller scale.

Incorporation of tryptophan analogues into staphylococcal nuclease, its V66W mutant, and Delta 137-149 fragment: spectroscopic studies

We have biosynthetically incorporated several tryptophan analogues into three forms of Staphylococcal nuclease to investigate the spectroscopic characteristics of these "intrinsic" probes and their effect on the structure of the proteins. The set of tryptophan analogues includes 5-hydroxytryptophan, 7-azatryptophan, 4-fluorotryptophan, 5-fluorotryptophan, and 6-fluorotryptophan. 5-Hydroxytryptophan and 7-azatryptophan have red-shifted absorbance spectra, and the latter has a red-shifted fluorescence, which is very sensitive to its environment (being heavily quenched in water). The fluorotryptophans can serve as 19F NMR probes, and 4-fluorotryptophan has a very low fluorescence quantum yield, thus making it a "knock-out" fluorescence analogue. The set of proteins studied includes wild-type nuclease, which has a single tryptophan site at position 140; its V66W mutant, which has a second tryptophan at position 66; and the Delta 137-149 fragment, V66W', which only has a tryptophan at position 66. The environments of positions 66 and 140 are significantly different; position 140 is near the end of the long C-terminal alpha-helix and is moderately solvent-exposed, whereas position 66 is in the beta-barrel core region of the protein and is surrounded by apolar side chains. Absorbance and 19F NMR spectra are used to estimate the extent of analogue incorporation for each protein. Steady-state and time-resolved fluorescence data are reported to characterize the emission of the analogues in these positions in the three proteins and to develop the use of the analogues as probes of protein structure and dynamics. Circular dichroism spectra are reported to show that, in all but a couple of cases, the secondary structure of the proteins containing the analogues is not significantly perturbed by the probes. Additionally, fluorescence anisotropy decay data show the variants of wild-type nuclease to have a rotational correlation time similar to that of tryptophan-containing nuclease.

Recurrence of accessory pathway conduction after successful radiofrequency ablation: histological findings

The histological findings from a patient with Wolff-Parkinson-White syndrome (right superior paraseptal accessory pathway) who underwent successful radiofrequency ablation and had recurrence of tachycardia one month later in the absence of overt pre-excitation are reported. Histology revealed three small, oval to circular shaped, whitish, smooth areas on the right endocardial surface, the one being situated at the atrial free wall, and the other two being at the ventricular aspect. A very small hole was present in the interventricular component of the membranus septum. The accessory pathway band passed to either side of the small hole albeit disrupted by fibrous tissue in places. These findings indicate that multiple applications may cause penetration of the myocardium, and to achieve success, complete disruption of the pathway at some point along its course is required. Recurrence of retrograde accessory pathway conduction can be explained with the impedance mismatch hypothesis.

Viable neurons with luxury perfusion in hydrocephalus

A woman with hydrocephalus due to aqueductal stenosis had functional imaging of cerebral perfusion and metabolism to demonstrate the effects of endoscopic third ventriculostomy--a new form of internal surgical shunting. Technetium-99m-ECD SPECT and 18F-FDG PET showed regional luxury perfusion at the left frontal region. Three months after a successful third ventriculostomy, a repeated imaging of cerebral perfusion and metabolism showed resolution of luxury perfusion and global improvement of both perfusion and metabolism. This concurred with postoperative clinical improvement. The paired imaging of cerebral perfusion and metabolism provides more information than just imaging perfusion or metabolism. Thus, the detection of perfusion and metabolism mismatch may open a new window of opportunity for surgical intervention.

Compatibility of vancomycin hydrochloride and famotidine 5% dextrose injection

The compatibility of vancomycin hydrochloride and famotidine in 5% dextrose injection stored at two temperatures was studied. Vancomycin hydrochloride and famotidine were reconstituted and diluted with 5% dextrose injection to form an admixture with a famotidine concentration of 0.2 mg/mL and a vancomycin concentration of 5 mg/mL. The admixture was stored in 100-mL vented intravenous containers in the dark at 4 and 25 deg C; three containers were stored at each temperature. A 2-mL sample was taken from each container after six and 12 hours and 1, 3, 5, 7, 10, 12, and 14 days of storage and visually inspected, tested for pH and assayed by a developed stability-indicating high performance liquid chromatographic method. Triplicate samples were prepared for each storage condition. No color change, precipitation or cloudiness was observed in any sample at any time during the study. Vancomycin 5 mg/mL and famotidine 0.2 mg/mL in admixtures in 5% dextrose injections are stable for 14 days at 4 and 25 deg C.

Cloning and characterization of two immunophilin-like genes, ilpA and fkpA, on a single 3.9-kilobase fragment of Aeromonas hydrophila genomic DNA

Antiserum to Aeromonas hydrophila A6 cell envelopes was shown in a previous study (C. Y. F. Wong, G. Mayrhofer, M. W. Heuzenroeder, H. M. Atkinson, D. M. Quinn, and R. L. P. Flower, FEMS Immunol. Med. Microbiol. 15:233-241, 1996) to protect mice against lethal infection by this organism. In this study, colony blot analysis of an A. hydrophila genomic library using antiserum to A. hydrophila A6 cell envelopes revealed a cosmid clone expressing a 30-kDa protein which has not been described previously in aeromonads. The nucleotide sequence of a 3.9-kb fragment derived from this cosmid which expressed the 30-kDa protein revealed two potential open reading frames (ORFs) with homology to known immunophilin proteins. ORF1 encoded a 212-amino-acid protein (molecular mass, 22.4 kDa) with 56% identity to the immunophilin SlyD protein of Escherichia coli. ORF1 was subsequently designated ilpA (immunophilin-like protein). ORF3 encoded a potential gene product of 268 amino acids with a typical signal sequence and a predicted molecular size of 28.7 kDa. The inferred amino acid sequence showed 46% identity with the sequence of the FkpA protein of E. coli and 40% identity with the sequence of the macrophage infectivity potentiator (Mip) protein of Legionella pneumophila. ORF3 was designated fkpA (FK506 binding protein) by analogy with the E. coli FkpA protein. Expression of the FkpA protein was confirmed by Western blot (immunoblot) analysis, which detected a 30-kDa protein, with antiserum to the Mip protein of Legionella longbeachae and a specific antiserum to anA. hydrophila 30-kDa membrane protein. PCR and Southern analysis showed that a DNA sequence encoding FkpA was found in all 178 aeromonads of diverse origins tested. A nonpolar insertion mutation in the fkpA gene did not attenuate virulence in a suckling mouse model nor did it affect the expression of hemolysins or DNase. This suggests that either the fkpA gene is not essential in the virulence of A. hydrophila under these conditions or there are other genes in A. hydrophila coding for proteins with similar functions.

Myocardial viability studies using fluorine-18-FDG SPECT: a comparison with fluorine-18-FDG PET

Multidetector SPECT systems equipped with a high-energy, or 511-keV collimator, have been proposed to offer a less expensive alternative to PET in myocardial viability studies with [18F]FDG. The objectives of this investigation included: (a) measuring the physical imaging characteristics of SPECT systems equipped with either a high-energy general-purpose collimator (HE), or the dedicated 511-keV collimator (UH), when imaging 511-keV photons, and comparing them with conventional FDG PET; and (b) directly and quantitatively comparing the diagnostic accuracy of SPECT, with either an UH or HE collimator, to that of PET in myocardial viability studies using 18F-FDG.

METHODS

Physical imaging characteristics of SPECT and PET were measured and compared. Both SPECT and PET studies were performed in two groups of 18 patients each, with Group I using HE SPECT and Group II using UH SPECT. Myocardial perfusion studies were also performed using 82Rb PET at rest and during dipyridamole stress to identify areas of persistent hypoperfusion. For each myocardial region with a persistent perfusion defect, a perfusion-metabolism match or mismatch pattern was established independently, based on the results of 18F-FDG SPECT as well as PET.

RESULTS

PET is superior to SPECT in all physical imaging characteristics, particularly in sensitivity and contrast resolution. PET had a sensitivity 40-80 times higher than that of SPECT, and its contrast resolution was 40-100% better than SPECT. Between FDG-SPECT using an HE collimator and that using a 511-keV collimator, the latter showed marked reduction in septal penetration (from 56% to 38%), improvement in spatial resolution (from 17 mm to 11 mm FWHM) as well as contrast resolution (from 34% to 45%), while suffering reduced system sensitivity (from 75 to 34 cpm/microCi). Patient studies demonstrated that although FDG-SPECT, using a HE or UH collimator, provided concordant viability information as FDG PET in a large majority of myocardial segments with persistent perfusion defects (88% and 90%, respectively), there is an excellent statistical agreement (kappa = 0.736) between SPECT with UH collimator and PET, while the agreement between SPECT using HE collimator and PET are moderate (kappa = 0.413).

CONCLUSION

Despite its markedly inferior physical imaging characteristics compared with PET, SPECT with the dedicated 511-keV collimator offers a low-cost, practical alternative to PET in studying myocardial viability using [18F]FDG. SPECT systems with a high-energy, general-purpose collimator, on the other hand, are inadequate in such studies.

Desmoid tumor (fibromatosis) of the breast. A clinician's dilemma--a case report and review

Desmoid tumor of the breast is a clinician's dilemma as it is difficult to differentiate it from carcinoma clinically, mammographically, and cytologically. Histologically, it must be distinguished from fibrosarcoma. Current management favors wide excision with clear margins. Recurrence is relatively common and usually occurs within 3 years of excision. Adjuvant hormonal therapy does not reduce local recurrence rates; evidence indicates that postoperative radiotherapy can improve the 10-year recurrence-free survival rate.

Biosynthetic incorporation of tryptophan analogues into staphylococcal nuclease: effect of 5-hydroxytryptophan and 7-azatryptophan on structure and stability

5-Hydroxytryptophan (5HW) and 7-azatryptophan (7AW) are analogue of tryptophan that potentially can be incorporated biosynthetically into proteins and used as spectroscopic probes for studying protein-DNA and protein-protein complexes. The utility of these probes will depend on the extent to which they can be incorporated and the demonstration that they cause minimal perturbation of a protein's structure and stability. To investigate these factors in a model protein, we have incorporated 5HW and 7AW biosynthetically into staphylococcal nuclease A, using a trp auxotroph Escherichia coli expression system containing the temperature-sensitive lambda cI repressor, Both tryptophan analogues are incorporated into the protein with good efficiency. From analysis of absorption spectra, we estimate approximately 95% incorporation of 5HW into position 140 of nuclease, and we estimate approximately 98% incorporation of 7AW, CD spectra of the nuclease variants are similar to that of the tryptophan-containing protein, indicating that the degree of secondary structure is not changed by the tryptophan analogues. Steady-state fluorescence data show emission maxima of 338 nm for 5HW-containing nuclease and 355 nm for 7AW-containing nuclease. Time-resolved fluorescence intensity and anisotropy measurements indicate that the incorporated 5HW residue, like tryptophan at position 140, has a dominant rotational correlation time that is approximately the value expected for global rotation of the protein. Guanidine-hydrochloride-induced unfolding studies show the unfolding transition to be two-state for 5HW-containing protein, with a free energy change for unfolding that is equal to that of the tryptophan-containing protein. In contrast, the guanidine-hydrochloride-induced unfolding of 7AW-containing nuclease appears to show a non-two-state transition, with the apparent stability of the protein being less than that of the tryptophan form.

Measurement of virulence of aeromonads using a suckling mouse model of infection

Virulent and avirulent strains of Aeromonas spp. were identified and virulence quantified using an animal model. Virulence was measured by determining a 50% lethal dose (LD50) 43 h after oral administration of live bacteria. The LD50 of virulent Aeromonas isolates ranged from log10 7.53 (mean) organisms to log10 8.88 (mean). Some isolates were avirulent in this model. Detection of cytotoxic activity in culture supernatants correlated with virulence (Fisher exact test, P = 0.0029). There was no correlation between LD50 and the source of the isolate, beta-haemolysis or lipopolysaccharide (LPS) banding profile on SDS-PAGE. In this animal model, virulence was multifactorial in that: (i) bacterial multiplication in the gut was associated with fatal infection; (ii) the increase in bacterial numbers in the gut of mice administered a lethal dose of bacteria was accompanied by accumulation of fluid; and (iii) there was evidence of extraintestinal spread of infection. Protection of suckling mice by rabbit antiserum to Aeromonas cell envelopes was observed.

Outcome of temporal lobe epilepsy surgery predicted by statistical parametric PET imaging

PET is useful in the presurgical evaluation of temporal lobe epilepsy. The purpose of this retrospective study is to assess the clinical use of statistical parametric imaging in predicting surgical outcome.

METHODS

Interictal 18FDG-PET scans in 17 patients with surgically-treated temporal lobe epilepsy (Group A-13 seizure-free, group B = 4 not seizure-free at 6 mo) were transformed into statistical parametric imaging, with each pixel representing a z-score value by using the mean and s.d. of count distribution in each individual patient, for both visual and quantitative analysis.

RESULTS

Mean z-scores were significantly more negative in anterolateral (AL) and mesial (M) regions on the operated side than the nonoperated side in group A (AL: p < 0.00005, M: p = 0.0097), but not in group B (AL: p = 0.46, M: p = 0.08). Statistical parametric imaging correctly lateralized 16 out of 17 patients. Only the AL region, however, was significant in predicting surgical outcome (F = 29.03, p < 0.00005). Using a cut-off z-score value of -1.5, statistical parametric imaging correctly classified 92% of temporal lobes from group A and 88% of those from Group B.

CONCLUSION

The preliminary results indicate that statistical parametric imaging provides both clinically useful information for lateralization in temporal lobe epilepsy and a reliable predictive indicator of clinical outcome following surgical treatment.

Thermodynamics of the unfolding and spectroscopic properties of the V66W mutant of Staphylococcal nuclease and its 1-136 fragment

Spectroscopic studies have been performed to characterize the solution structure of the V66W mutant of Staphylococcal nuclease and the corresponding 1-136 fragment, referred to as V66W'. Whereas wild-type nuclease has a single tryptophan residue at position 140, the V66W mutant has a second tryptophan residue at position 66, which is the only such residue in V66W'. Steady-state and time-resolved fluorescence studies show Trp-66 in V66W' to have a blue emission, a relatively large fluorescence quantum yield, a long lifetime, a significant degree of protection from solute quenchers, and to depolarize with a relatively long rotational correlation time. These results characterize Trp-66 in V66W' as being a buried residue, which indicates that this fragment retains some global structure. Circular dichroism (CD) data are consistent with the fragment having lost most of the alpha-helical content of the wild type, while retaining beta-sheet structure. The CD spectrum in the aromatic region also suggests that Trp-66 in the fragment experiences an asymmetric environment, which is not identical to that in the full length mutant, V66W. In addition, optical detection of triplet state magnetic resonance (ODMR) spectroscopy can clearly resolve the tryptophan residues and demonstrates differences between the local environment of Trp-66 in V66W and in V66W', as well as small differences in the Trp-140 environment in wild type and in V66W. Guanidine-HCl induced and thermally induced unfolding studies were performed by simultaneously acquiring CD and fluorescence data as a function of the perturbation and then performing a global analysis of such multiple data sets in terms of two-state and three-state unfolding models. Whereas data for wild-type nuclease and the V66W' fragment are well characterized by a two-state unfolding model, data for the V66W mutant are better characterized by a three-state process. That is, both the denaturant- and temperature-induced unfolding of V66W involves the significant population of an equilibrium unfolding intermediate. Our global analyses yield thermodynamic parameters for the unfolding transitions, and we show that the data for V66W can be described by a constrained three-state model in which the transition of the intermediate to the fully unfolded state is fixed to have the same thermodynamic parameters that describe the unfolding of the V66W' fragment.

Choledocholithiasis in anomalous biliary system

Although congenital biliary abnormalities are common, preduodenal portal vein is very rare, not to mention preduodenal common bile duct (CBD) which has not been described before in the literature. A case with both anomalies complicated by biliary tract stones is reported. A brief review of embryonic development is also presented to explain the unusual biliary anatomy of this patient.

Factor X Stockton: a mild bleeding diathesis associated with an active site mutation in factor X

A unique blood coagulation factor X variant has been identified in a family with a history of bleeding. Plasma from affected family members had prolonged prothrombin times and activated partial thromboplastin times, low to below normal factor X coagulant activity, and normal factor X antigen levels. Sequencing of DNA from the propositus revealed a single G to A substitution in one allele of factor X at base 964 resulting in an amino acid substitution of Asn for Asp at residue 282. This residue corresponds with the active site Asp102 of chymotrypsin. The substitution eliminates a TaqI restriction site and provided the basis for a screening assay to detect the mutation in polymerase chain reaction (PCR) amplified factor X exon VIII DNA. Fourteen additional family members were identified as having the mutation at base 964. Plasma factor X purified from the proposita using an anti-factor X monoclonal antibody immunoadsorbent exhibited an approximately 50% decrease in specific activity compared with factor X purified from a normal individual in a similar manner. Bleeding in family members with the mutation, termed factor X Stockton, appears to be due to disruption of normal hemostasis by the presence in plasma of circulating abnormal factor X. Factor X Stockton is the first naturally occurring substitution at the active site Asp of a serine protease and underscores the importance of this amino acid residue in factor Xa coagulant activity.

Sexuality of women after mastectomy

Changes in sexual functioning, attitudes and sexual behaviour in local women after mastectomy and conservative breast surgery for breast cancer were assessed in this study. Given the social bearing, only married women agreed to be entered into the study. The complexities of variables other than breast loss, contributing to sexual difficulties were recognized and assessed. Through questionnaires designed for local women, a significant proportion of mastectomy women were found to have disturbances in at least one area in their sexual functioning after surgery. A significant number experienced changes in their sexual habits as well.