Clinical management and treatment outcomes of Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC), first described in 1972, is an uncommon, highly malignant tumour of skin. Its aetiology is unknown although the tumour occurs most frequently in sun-exposed sites. This skin cancer is characterized by a high incidence of metastases, local and regional recurrence and has a high mortality. Few survival data beyond 3 years are available. Treatment strategies include wide local excision of the primary and lymph node dissection, as indicated together with adjuvant radiotherapy. The tumour has also been shown to be chemosensitive. Definitive treatment is inconclusive due to the relative rarity of this malignancy.

METHODS

A retrospective study was undertaken between the years 1985 and 1996 of 33 patients with MCC at Concord Repatriation General Hospital (CRGH). Demographic details were noted, together with the site and appearance of the primary lesion and the sites and date of metastases. The response and outcome to various modalities of treatment were documented.

RESULTS

There were 27 men and six women with an average age of 80 years (range: 60-86 years). The primary lesion in the present series most often resembled a basal cell carcinoma (BCC), with 53% occurring in the head and neck region. Twenty-seven patients (82%) developed metastatic disease, with an average interval of 13.4 months between diagnosis of the primary lesion and the development of metastases. The incidence of locoregional recurrence in the present series was 42%. Radiation combined with surgery achieved locoregional control in 15 of 19 patients with primary, regional or recurrent locoregional disease. Fourteen patients died of MCC and five others from unrelated causes. The 14 survivors have a mean survival of 54 months with six patients surviving more than 5 years.

CONCLUSIONS

Local excision together with regional lymph node clearance as indicated, combined with adjuvant radiation treatment was associated with an improved survival. The role of chemotherapy remains unclear.

Cloning and characterization of two isoforms of the zebrafish thyrotroph embryonic factor (tef alpha and tefbeta)

We have cloned and sequenced two cDNAs representing two isoforms of the zebrafish thyrotroph embryonic factor (TEF) gene products (tef alpha and beta), a member of the PAR subfamily of bZIP transcription factors. The two isoforms encode two potential proteins of 300 and 293 amino acids respectively. Sequence comparison analysis indicate that the zebrafish tefs show high homology to PAR family of transcription factors of other species in the PAR domain, DNA binding domain and leucine zipper domain. Expression analysis by Northern blot and RT-PCR indicates that tef alpha and tefbeta are expressed in adult fish and throughout the zebrafish embryonic development. In addition, the two tefs are expressed in some adult tissues, but not others.

Effects of dobutamine, epinephrine and norepinephrine on the hemodynamics of dogs during hemorrhagic shock

BACKGROUND

The present study examined how effective epinephrine (EPI), norepinephrine (NOR) and dobutamine (DOB) were for resuscitating dogs subjected to hemorrhagic shock (HS).

METHODS

Dogs (n = 42) were randomly assigned to seven test groups: EPI, NOR and DOB infusion with and without HS, and HS dogs with no catecholamine. Following baseline measurements, the dogs were bled to a mean arterial blood pressure of 40 mmHg. After 3 h, the shed blood was reinfused. EPI and NOR (0.1, 0.4 and 1.6 micrograms/kg/min) and DOB (2.5, 5.0 and 10.0 micrograms/kg/min) were given and the dog allowed to stabilize for 30 min. Hemodynamic and blood gas data were obtained at 6 time points (control, shock, resuscitation and after catecholamine infusion).

RESULTS

There was no significant difference in myocardial performance (dP/dt) between the respective shocked and unshocked groups after blood resuscitation. In dogs without catecholamine infusion, CO and SvO2 continued to decline whereas SVR increased. DOB (2.5 to 10.0 micrograms/kg/min) with and without shock improved CO, LV dP/dt, SVR and SvO2. EPI did not further improve CO or SvO2 at infusion rates above 0.1 microgram/kg/min (with and without shock). NOR did not improve SvO2 at any infusion rate (with and without shock) and did not improve CO until the infusion rate was at 0.4 microgram/kg/min (without shock).

CONCLUSIONS

This study advocates the use of both volume replacement therapy and DOB for resuscitation of HS dogs.

Anti-Helicobacter pylori treatment in bleeding ulcers: randomized controlled trial comparing 2-day versus 7-day bismuth quadruple therapy

BACKGROUND

One-week bismuth triple therapy has been established to be highly effective in curing H. pylori infection, but patient compliance has been the major factor of success in therapy. For patients hospitalized for ulcer bleeding, an effective regimen that can completed before discharge will ensure full compliance.

AIM

To compare 2-day versus 1-wk bismuth triple therapy plus omeprazole in curing H. pylori infection and bleeding peptic ulcers.

METHODS

100 patients with non-actively bleeding duodenal (DU) or gastric ulcers (GU) and confirmed H. pylori infection were randomized to receive either bismuth subcitrate 120 mg, tetracycline 500 mg, and metronidazole 400 mg four times daily for 1 wk (OBTM-7) or bismuth subcitrate 240 mg, tetracycline 500 mg, and metronidazole 400 mg four times daily for 2 days (OBTM-2). Both groups of patients also received omeprazole 20 mg twice daily for the first week. In the OBTM-2 group, the anti-Helicobacter therapy was finished during hospitalization. Endoscopy was repeated 5 wk after randomization to monitor ulcer healing and determine H. pylori status. Side effects related to the anti-Helicobacter therapy was graded as follows: A, mild discomfort, which did not affect daily activity; B, moderate discomfort affecting daily activity; and C, severe discomfort and patients discontinued therapy.

RESULTS

Forty-six patients in the OBTM-2 group and 50 in the OBTM-7 group returned for follow-up endoscopy. With an intention-to-treat analysis, ulcer healing was achieved in 44 of 46 patients (95.7%) in the OBTM-2 group versus 49 of 50 (98%) in the OBTM-7 group, p = 0.61. H. pylori eradication was successful in 35 of 46 patients (76.1%) in the OBTM-2 and in all 50 patients (100%) in the OBTM-7 group, p = 0.00024. There was no difference in the severity of side effects experienced by the patients in the OBTM-2 group than in the OBTM-7 group (19 vs 32%, p = 0.16). None of the patients had rebled during the period of follow-up.

CONCLUSION

Despite similar efficacy in ulcer healing, the 2-day quadruple therapy is less effective than the 1-wk regimen in curing H. pylori infection.

Common occurrence of an antiidiotypic antibody that recognizes T14+ anti-DNA antibodies in patients with systemic lupus erythematosus

OBJECTIVE

To investigate whether antibodies to a T14 anti-DNA antibody can be found in patients with systemic lupus erythematosus (SLE).

METHODS

Seventy-six serum samples (37 from patients with SLE) were randomly selected from among sera submitted for routine antinuclear antibody testing. Short, overlapping peptides based on the partial VH (variable region of the heavy chain) sequence of the T14 antibody were synthesized on multipins and screened for reactivity with SLE sera. In addition, selected peptides from T14 and related proteins were synthesized in bulk and screened for reactivity with both SLE and control sera. A monoclonal antibody was generated to determine the prevalence of the T14 idiotype (T14+ Id) in the different study populations.

RESULTS

Antibodies were detected by a peptide based on the third complementarity-determining region (CDR3) of the T14 protein in 15 (41%) of 37 patients with SLE or 15 (54%) of 28 who had anti-DNA antibodies, in 3 (9%) of 34 patients without anti-DNA antibodies (9 of whom had SLE), and in 6 (10%) of 57 healthy controls. In SLE sera, the antiidiotypic (anti-Id) responses (IgM and IgG) correlated well with the anti-DNA responses (IgG), and both responses correlated well with the T14+ Id activity in SLE sera. Control peptides based on the 18/2 (16/6+ Id) and S107 proteins detected low antibody activities in SLE sera, attributable to cross-reactivity with the T14 peptide. A peptide based on an unrelated human antibody was not reactive with these sera.

CONCLUSION

Anti-Id antibodies directed to T14 VHCDR3 were found commonly in the sera of patients with SLE, and they appeared to be induced by the anti-DNA antibodies present in the sera. Based on these findings, these secondary antibodies may be pathogenic in SLE.

The prevalence of and risk factors for neck pain in Hong Kong Chinese

BACKGROUND

Neck pain has been found to be a prevalent musculoskeletal complaint among Caucasians living in Europe and North America. The prevalence of and risk factors for this condition have not been studied among Chinese living in urbanised cities. The objective of this study was to describe the prevalence of and risk factors for neck pain in Hong Kong Chinese.

METHODS

A household survey was conducted in two housing blocks, one being government-subvented housing and the other being private housing. Eight hundred men and women who were 30 years and older were interviewed on the occurrence and characteristics of neck pain, occupations and recreational activities. The life-time and one-year prevalence of neck pain were calculated, and the odds ratio (OR) and 95 per cent confidence intervals (95 per cent CI) for various risk factors were derived by logistic regression.

RESULTS

The one-year prevalence of neck pain was 15 per cent and 17 per cent in men and women, respectively. The OR was 1.6 (95 per cent CI = 1.2-2.4) for living in private housing and 2.1 (95 per cent CI = 1.1-4.0) for working as managers and professionals. Subjects with neck pain spent more time reading and a history of trauma to the neck was a significant risk factor for subsequent pain (OR = 5.6, 95 per cent CI = 3.3-9.4).

CONCLUSION

Neck pain is a prevalent problem in Hong Kong Chinese, particularly among subjects of a high socioeconomic status. There was little association between life-style and neck pain, although subjects with neck pain spent more time in reading.

Upregulation of adhesion molecule expression on endothelial cells by anti-DNA autoantibodies in systemic lupus erythematosus

The mechanism of vasculopathy in systemic lupus erythematosus (SLE) remains unclear and the evidence for a direct pathogenic role of anti-double-stranded DNA antibodies (anti-dsDNA) is not strong. Our study aims to determine whether anti-dsDNA exerts any effect on the expression of adhesion molecules on endothelial cells. IgG was purified from 17 patients with SLE (median anti-dsDNA titer, 404 IU/ml) and from 9 healthy controls (median titer 16 IU/ml). Anti-dsDNA-depleted polyclonal IgG (anti-dsDNA-dep-IgG) (median anti-dsDNA titer 17 IU/ml) was prepared from sera of these patients with SLE by affinity chromatography with DNA cellulose column. Expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin on human umbilical vein endothelial cells (HUVEC) cultured with either control IgG or anti-dsDNA were compared by flow cytometry. The levels of adhesion molecules in the supernatant of cultured HUVEC were assessed by sandwich ELISA. Compared with either control IgG or anti-dsDNA-dep-IgG, HUVEC incubated with anti-dsDNA expressed a significantly higher mean fluorescence intensity of ICAM-1 and in VCAM-1 and a higher supernatant concentration of ICAM-1 and VCAM-1 but not E-selectin. At the same time, ICAM-1 mRNA was also raised with increased neutrophil adherence in HUVEC incubated with anti-dsDNA. Pretreatment of HUVEC with native DNA or histone before incubation with anti-dsDNA did not increase the expression of adhesion molecules. Our study provides in vitro evidence that anti-dsDNA could play an important pathogenic role in inducing inflammatory injury of vascular endothelium in SLE.

Total body protein status assessed by different estimates of fat-free mass in adult peritoneal dialysis patients

OBJECTIVE

To assess the usefulness of fat-free mass (FFM) as an index of total body protein (TBPr) status in continuous ambulatory peritoneal dialysis (CAPD) patients.

DESIGN

TBPr was measured by in vivo neutron activation analysis (IVNAA) and expressed as a standardised protein index (PI). FFM was estimated by dual energy X-ray absorptiometry (DXA), whole body counting of total body potassium (TBK), and creatinine kinetics (CK), and expressed as a standardised FFM index (FFMI). FFM was also determined by a criterion method based on four compartment model (4CM) which is defined as the sum of total body water determined by D2O dilution, TBPr determined by IVNAA, bone mineral determined by DXA, and glycogen estimated to be 4.4% of TBPr. Each patient was measured within a four hour period by all methods.

SETTING

Body Composition Laboratory, Monash Medical Centre.

SUBJECTS

Six male and twelve female CAPD patients (33-77 years).

RESULTS

FFMI assessed by DXA and by TBK agreed with measurements of PI on identifying the mean TBPr status of the CAPD group as significantly below a comparable normal reference population (mean Z score: PI = -1.01 (P < 0.05); FFMI by DXA = -0.50 (P < 0.05); FFMI by TBK = -1.24 (P < 0.05)). In contrast, FFMI assessed by CK did not reveal a significantly reduced TBPr status (mean Z score: -0.70 (NS)). Furthermore, significant linear correlations were noted between PI and FFMI estimated by DXA and by TBK (r = 0.57 (P < 0.05) vs r = 0.69 (P < 0.05)) however no significant correlation was observed between PI and FFMI estimated by CK (r = 0.36 (NS)). Moderate variation in FFM hydration did not compromise the ability of DXA, TBK or CK to differentiate between protein deleted, normal and enriched patients. Comparison of FFM estimates between the criterion method and either DXA, TBK or CK revealed no significant bias (+ 1.8 kg vs -2.0 kg vs +0.8 kg) and respective SEE values of 3.8 kg (8.3%), 5.9 kg (14.3%) and 9.6 kg (21.7%).

CONCLUSION

The findings of this study indicate that FFM estimated by either DXA or the whole body counting of TBK is a useful index of TBPr status in CAPD patients. However, FFM assessed by CK does not appear to be an appropriate index of TBPr status in CAPD patients.

Dialyzer reuse: interaction between dialyzer membrane, disinfectant (formalin), and blood during dialyzer reprocessing

The growing practice of dialyzer reuse in recent years is mainly based on medical and economic considerations. However, adverse reactions such as immunohemolytic anemia due to anti-Nform antibody associated with dialyzer reuse have been reported. In this study, scanning electron microscopy and cytologic staining were used to evaluate the interaction between blood components and the reprocessed synthetic dialyzer membrane (polysulfone) after disinfectant (formaldehyde) treatment. The results showed that various blood components such as fibrin and blood cells still adhered to the dialyzer membrane after reprocessing. The study also demonstrated that the adhered denatured blood components could be detached by sonication and/or simulated hemodialysis and then gain access into the circulation. The re-entry of the denatured blood components to the patients exposed to reused dialyzers may result in an enhanced immunological response which may contribute to antibody formation (such as anti-Nform antibody) with a reused hemodialyzer.

Increased release of von Willebrand factor antigen from endothelial cells by anti-DNA autoantibodies

OBJECTIVE

To determine whether antibodies to double stranded DNA (anti-dsDNA) have a pathogenic role in systemic lupus erythematosus (SLE).

METHODS

IgG was purified from 17 patients with SLE (median anti-dsDNA titre 1212 IU/ml) and nine healthy controls (median titre 40 IU/ml). Anti-dsDNA depleted polyclonal IgG (median anti-dsDNA titre 17 IU/ml) was also prepared from sera of the 17 patients by affinity chromatography on a DNA cellulose column. Binding to antiendothelial cell antibodies (AECA) and expression of von Willebrand factor (VWF) antigen by cultured human umbilical vein endothelial cells (HUVECs) were studied by flow cytometry.

RESULTS

The percentage of HUVECs binding to AECA or expressing VWF was greater for cells incubated with IgG from patients with SLE than for cells incubated with control IgG, though values did not reach statistical significance; nevertheless, HUVECs incubated with IgG from patients expressed a greater mean fluorescence intensity with AECA (p = 0.0001) and greater VWF expression (p = 0.019). Both the fluorescence intensity and percentage of HUVECs binding to AECA or expressing VWF were significantly greater in HUVEC incubated with IgG containing anti-dsDNA than in those incubated with anti-dsDNA depleted IgG. The concentration of VWF in the supernatant was significantly increased in HUVECs incubated with IgG containing anti-dsDNA compared with control IgG or anti-dsDNA depleted IgG. Pretreatment of HUVECs with native DNA before incubation with IgG from lupus patients did not increase binding to AECA, or expression or release of VWF.

CONCLUSIONS

Our study provides in vitro evidence that antibodies to DNA have a pathogenic role in the induction of inflammatory injury of the vascular endothelium in SLE.