Heterodigital arterialized flaps for large finger wounds: results and indications

Deep defects of the hand and fingers with an unhealthy bed exposing denuded tendon, bone, joint, or neurovascular structures require flap coverage. However, the location and size of the defects often preclude the use of local flap coverage. Free-flap coverage is often not desirable either, because the recipient vessels may be unhealthy from surrounding infection or trauma. In such situations, a regional pedicled flap is preferable. A solution to this is the heterodigital arterialized flap. This flap is supplied by the digital artery and a dorsal vein of the finger for venous drainage. Unlike the neurovascular island flap, the digital nerve is left in situ in the donor finger, thus avoiding many of the neurologic complications associated with the Littler flap. The digital artery island flap is centered on the midlateral line of the donor finger. It extends from the middorsal line to the midpalmar line. The maximal length of the flap is from the base of the finger to the distal interphalangeal joint. By preserving the pulp and the digital nerve, a sensate pulp on the donor finger remains that reduces donor-finger morbidity and also preserves fingertip cosmesis. Twenty-nine flaps were performed in 29 patients and the outcomes in the donor finger and the reconstructed finger were reviewed. The flap survival was 100 percent. There were no cases of flap ischemia or flap congestion. Good venous drainage of the flap through the additional dorsal vein was helpful in preventing the occurrence of early postoperative venous congestion, which is common in island flaps of the fingers, which depend on only the venae comitantes for drainage. Donor-finger morbidity, measured in terms of range of motion and two-point discrimination in the pulp, was minimal. Ninety-seven percent of the donor fingers achieved excellent or good total active motion according to the criteria of Strickland and Glogovac. Pulp sensation in the donor fingers was normal in 28 of the 29 donor fingers. No cold intolerance of the donor finger or the adjacent finger is reported in this series.

Sweet's syndrome associated with Mycobacterium chelonae and herpes simplex virus infections: a case report

INTRODUCTION

We report a case of Sweet's syndrome associated with Mycobacterium chelonae and herpes simplex virus infection.

CLINICAL PICTURE

A 56-year-old Chinese woman presented with a granulomatous subglottic mass and right lung nodules, which responded to a 9-month course of anti-tuberculous treatment. Subsequently, she developed genital herpes simplex virus infection, which was followed by a cutaneous eruption with vesicular plaques associated with fever, bilateral cervical lymph nodes and neutrophilia. Mycobacterium chelonae was isolated from lymph node cultures. The cutaneous presentation of Sweet's syndrome was confirmed on skin biopsy. There was no evidence of underlying immunosuppression, malignancy or connective tissue disease.

TREATMENT

She was treated with rifampicin, clarithromycin and oral prednisolone.

OUTCOME

There was complete resolution of her cutaneous lesions and cervical lymphadenopathy.

CONCLUSION

The association between Sweet's syndrome and Mycobacterium chelonae as well as herpes simplex virus, though rare, should be considered in all patients presenting with Sweet's syndrome.

Anterior subfascial transposition of the ulnar nerve

After anterior subfascial transposition, the ulnar nerve lies superficial to the flexor-pronator muscle group but deep to its fascia. Eight patients with cubital tunnel syndrome were treated with this method and reviewed retrospectively. The average age at the time of operation was 52 years. All patients had severe cubital tunnel syndrome based on Dellon's classification. The average follow-up period was 2 years and 9 months. Post-operative outcome assessment was based on the modified Bishop rating system. Six patients had excellent and two had good outcomes. All were back at work by the 5th post-operative week. There were no complications or recurrence of symptoms. Anterior subfascial transposition of the ulnar nerve is an effective method of surgical treatment for patients with severe cubital tunnel syndrome.

Isolation and characterization of cDNA clones encoding ADP-glucose pyrophosphorylase from sago palm (Metroxylon sagu)

Four ADP-glucose pyrophosphorylase cDNA clones were isolated from mature leaves and pith of sago palm by the polymerase chain reaction (PCR) technique. Three of them (agpp10, agpp12 and agpl19) encoded the AGP large subunit, while the fourth clone (agpl1) encoded the small subunit. agpp10 and agpp12 were isolated from pith, agpl19 was isolated from mature leaves, while agpl1 from both tissues. In addition, a full-length cDNA of agpl1 was successfully isolated from a cDNA library of mature leaves by a PCR-based screening technique. Semi-quantitative analysis suggests that agpp10 and agpp12 were detectable only in pith, agpl19 only in leaves, while agpl1 was expressed in both leaves and pith tissues.

The cloning of Ty1-copia-like retrotransposons from 10 varieties of banana (Musa Sp.)

Ty1-copia-like retrotransposons have been identified and investigated in several plant species. Here, the internal region of the reverse transcriptase (RT) gene of Ty1-copia-like retrotransposons was amplified by PCR from total genomic DNA of 10 varieties of banana. Two to four clones from each variety were sequenced. Extreme heterogeneity in the sequences of Ty1-copia-like retrotransposons from all the varieties was revealed following sequence analysis of the reverse transcriptase (RT) fragments. The size of the individual RT gene fragments varied between 213 and 309 bp. Southern blots of genomic DNA digested from Musa acuminata and other banana varieties probed with W8 clone from M. acuminata and A4 clone from Pisang Abu Nipah showed similar strong, multiple restriction fragments together with other faint hybridization band patterns with variable intensities indicating the presence of many copies of the Ty1-copia-like retrotransposons in the genomes. There was no correlation between retroelement sequence and the banana species (with A or B genomes) from which it arose, suggesting that the probes are not useful for tracking genomes through breeding populations.

Quantitative three-dimensional anatomy of lumbar vertebrae in Singaporean Asians

This paper details the quantitative three-dimensional anatomy of lumbar vertebrae L1-L5 from Asian (Singaporean) subjects based on 60 lumbar vertebrae from 12 cadavers. The purpose of the study was to measure the dimensions of the various parameters of the lumbar vertebrae and thereafter to compare the data with a study performed on Caucasian specimens. Measurements were taken with the aid of a three-dimensional digitiser. The means and standard errors for linear, angular and area dimensions of the vertebral body, spinal canal, pedicle, and spinous and transverse processes were obtained for each lumbar vertebra. From this comparison, it was found that the dimensions of the vertebral body of the Asian subjects are slightly larger, with a maximum average difference of 8% for the posterior vertebral body height. The dimensions of the spinal canal, pedicle, and spinous and transverse processes of Asian subjects are smaller. The greatest difference can be found in the spinal canal area and pedicle width, which are smaller by an average of 30% and 20%, respectively. With the exception of the spinal canal depth, spinal canal area and pedicle width, all other parameters compared show a similar trend. The findings can provide more accurate modelling for analysis and spinal implant design and also allow more precise clinical diagnosis in sub-Asian groups.

Cardiovascular comorbidity and mortality in patients starting peritoneal dialysis: an American midwestern center experience

End-stage renal disease (ESRD) patients frequently have multiple comorbidities, and cardiovascular disease remains the leading cause of death in these patients. The objectives of the present study were (1) to characterize the number and severity of cardiovascular comorbidities at the start of peritoneal dialysis (PD), and (2) to determine the impact of these comorbidities on mortality. We retrospectively studied all ESRD patients starting peritoneal dialysis at our center between 1990 and 1999. The baseline cardiovascular comorbid factors were categorized as ischemic heart disease, congestive heart failure, arrhythmia, peripheral vascular disease, and cerebrovascular disease. The severity of each factor was scored from 0 to 3. The number of comorbidities and the total cardiovascular comorbidity severity scores were determined for each patient. Cardiovascular deaths included those attributed to sudden death, cardiac disease, cerebrovascular disease, and complications of peripheral vascular disease. Of the 191 patients, 105 were men, and 105 (55%) had diabetes mellitus. The mean age was 60.8 +/- 13.3 years and the mean time on PD was 18.8 +/- 16.3 months. As the number of cardiovascular comorbidities increased, the proportion of patients who died of cardiovascular causes increased eighteen-fold. At each level of cardiovascular comorbidity, diabetic patients starting dialysis were younger, and their survival time was shorter as compared with non diabetic patients. Baseline comorbidity determination is important, as comorbidities are prognostic harbingers of eventual complications.

Transport and budding at two distinct sites of visible nucleocapsids of West Nile (Sarafend) virus

It has been difficult to detect and visualize the physical nucleocapsid particles during the replication process of the flaviviruses. The use of cryo-immunoelectron microscopy has clearly revealed the capsid proteins and nucleocapsid particles of West Nile (Sarafend) virus (a flavivirus) for the first time. Physical nucleocapsid particles accumulated in large numbers from 8 hr postinfection. Double immunolabeling of the envelope and capsid proteins showed a close association of these structural proteins for most of the replication cycle. By 10 hr postinfection, budding of nucelocapsids from the plasma membrane was very obvious. Although maturation at the plasma membrane was the dominant mode, during late infection, intracellular maturation into large vacuoles was also observed.

Hypertensive basal ganglia hemorrhage: a prospective study comparing surgical and nonsurgical management

BACKGROUND

The optimal treatment of hypertensive supratentorial intracerebral hemorrhage is still debated. Some studies have shown no improvement in survival or functional outcome after surgery when compared to conservative management while others have shown otherwise.

METHODS

This study was a prospective trial, matching patients for hematoma volume and Glasgow Coma score on admission.

RESULTS

There were a total of 34 patients. Seventeen were treated conservatively and 17 surgically. There was no significant difference between the two groups in terms of age, GCS, hematoma volume, or presence of intraventricular blood. At 3, 6, and 12-month follow-up, they were assessed using the Modified Barthel Index by a blinded observer. There was no difference between the two groups at 3, 6, or 12 months follow-up. The mortality rate was similar in the two groups.

CONCLUSIONS

Based on this study and review of the literature, we cannot recommend routine evacuation of clots to treat these hemorrhages.

Pemphigus vulgaris following varicella infection

We describe a 26-year-old Indian man who presented with chickenpox and subsequently developed pemphigus vulgaris 17 days after initial resolution of lesions. The mechanism of progression from one disease to the other is postulated to be that of epitope spreading or molecular mimicry.

Hypodermoclysis or subcutaneous infusion revisited

AIM OF STUDY

To review the use of hypodermoclysis in a local Hospice.

METHOD

A review of all hypodermoclysis carried out over a six-month period was conducted. Special attention was paid to the reason for starting and stopping the drip, duration of the drip, complications, the type and amount of solution infused.

RESULTS

Fifty-one (19%) out of 266 patients received hypodermoclysis during their stay. This constituted 5.9% of total patient-days in the study period. Vomiting and drowsiness were the main reasons for the use of drip. The commonest reason for stopping the drip was patient demise. Complications seen were drip site redness (16%), extravasation (15%) and bleeding (2.5%) There was no overt clinical sepsis in any of the patients.

CONCLUSION

Hypodermoclysis is an easy and convenient means of providing hydration. The availability of a standard protocol with clearer guidelines on its use will help to reduce procedure-related complications and promote wider adoption of the practice.

Chemical degradation of composite restoratives

The chemical environment is one aspect of the oral environment, which could have an appreciable influence on the in vivo degradation of composite restoratives. The effects of chemical media on surface hardness of four composite restoratives (Silux [SX], Z100 [ZO], Ariston [AR] and Surefil [SF]) were investigated. The relationship between hardness and the thickness of the degradation layer was also studied. Thirty six specimens (3 x 4 x 2 mm) were made for each material. Following polymerization, the specimens were stored in artificial saliva at 37 degrees C for 24 h. The specimens were then randomly divided into six groups of six, subjected to microhardness testing (load = 500 gf, dwell time = 15 s) and stored in the following chemicals for 1 week at 37 degrees C: artificial saliva (S), distilled water (W), 0.02 N citric acid (C), 0.02 N lactic acid (L), heptane (H) and 75-25% ethanol-water solution (E). After conditioning, the specimens were again subjected to hardness testing and sectioned. Change in hardness (DH) was computed and the thickness of the degradation layer (DL) was measured using a computerized image analysis system at 600x magnification. Results of statistical analysis (ANOVA/Scheffe's [P < 0.05]) of DH based on materials were as follows: SX - E > all other mediums; ZO - W > C; and AR - S, W, E > H (> indicates significantly greater hardness change). No significant difference in DH was observed between the different chemicals for SF. The effects of chemical media on DH were found to be material dependent. A significant but weak positive correlation (Pearson's correlation [P < 0.05]) exists between change in hardness and thickness of the degradation layer.

Comparative study of pemphigus vulgaris and pemphigus foliaceus in Singapore

This is a retrospective study of all patients diagnosed to have pemphigus in our centre over a 3 year period. The case records of all patients with pemphigus from January 1995 to December 1997 were analysed. Fifty patients were diagnosed to have pemphigus during the study period. The diagnoses were pemphigus vulgaris in 31 patients, pemphigus foliaceus in 16, paraneoplastic pemphigus in two and IgA pemphigus in one. The average titre of anti-intercellular antibodies in patients with pemphigus vulgaris (1:96) was higher than the titre in patients with pemphigus foliaceus (1:69). The average initial dose of prednisolone required for disease control in patients with pemphigus vulgaris (62 mg/day) was significantly higher than that required for patients with pemphigus foliaceus (44 mg/day). In our study population, pemphigus vulgaris is a more severe and chronic disease than pemphigus foliaceus, as reflected in the higher titre of anti-intercellular antibodies, higher dose of systemic corticosteroids required for control of the disease, the longer duration to achieve complete remission and longer follow-up period.

Spindle cell variant of epithelioid sarcoma: an easily misdiagnosed tumour

Epithelioid sarcoma is a histologically distinct soft tissue sarcoma of high grade malignancy. We report a case of epithelioid sarcoma in a young man who presented with multiple nodules over the left forearm, with bony invasion and pulmonary metastases. The histological features of the dermal tumour were those of a malignant spindle cell tumour with positive cytokeratin and vimentin staining and differed from the classical epithelioid sarcoma in its absence of typical necrobiotic nodular epithelioid pattern. It was the clinical presentation and the histology of the subcutaneous nodules that led to the final diagnosis of epithelioid sarcoma. This case illustrates a predominance of spindle cell pattern in the dermal tumour of epithelioid sarcoma, which has previously been reported as fibroma-like variant of epithelioid sarcoma.

Late-onset hydroa vacciniforme: two case reports

Hydroa vacciniforme (HV) is a rare blistering photodermatosis that heals with vacciniform scarring, with onset usually in childhood and spontaneous resolution by early adulthood. We report two cases of HV seen at the National Skin Centre, Singapore, both with a late onset at 20 years of age, during compulsory military service, and one with a less typical non-vesicular presentation, that initially caused some diagnostic difficulties.

Protein nutrition status of adult patients starting chronic ambulatory peritoneal dialysis

Malnutrition is an important determinant of outcome in patients on dialysis. Its cause is multifactorial and its detection is important when patients embark on dialysis. In this study, we used various indices to assess the prevalence of malnutrition as reflected in protein intake, anthropometric effect, and serum protein level. To avoid the effect that dialysis has on malnutrition, we studied 37 patients who had just started continuous ambulatory peritoneal dialysis (CAPD). Of these new patients, 42% had a residual urea clearance below 1.0 mL/min. In 51% of the patients, serum albumin level was below 33 g/L; in 14%, body mass index was below 19; and in 39%, dietary protein intake was below 0.8 g per kilogram of body weight per day. A total of 76% of our patients had at least one of these three indices. In 8% of the patients, lean body mass was below 60%. We conclude that protein malnutrition is a significant problem in our patients starting CAPD. Dialysis-dependent factors were not implicated, as the patients were studied at the start of dialysis. Low intake of protein was a major problem and may have contributed significantly to malnutrition. The low residual urea clearance implied that dialysis was started relatively late and may have contributed to the low protein intake.

Recurrent nasopharyngeal carcinoma presenting as diffuse dermal lymphatic infiltration in the neck: three case reports

BACKGROUND

Any malignancy has the propensity to metastasize to skin. The frequency of skin metastases vary in different tumors and occur in about 0.7% to 10% of all patients diagnosed with cancer. It is rare in nasopharyngeal carcinoma.

METHOD

Three cases of relapsed nasopharyngeal carcinoma with diffuse dermal involvement were described. Their clinical presentation, results of investigations, and response to treatment were reviewed. Literature review of similar forms of presentation was done by means of a MEDLINE search.

RESULTS

At the time of dermal relapse, all three patients had a uniform clinical picture of facial, periorbital, and lip swelling associated with stridor and dysphagia. Histologic findings showed dermal infiltrates of malignant cells, and CT scan showed diffuse infiltration of the subcutaneous tissue. Despite chemotherapy, the clinical course was relentless.

CONCLUSION

This report describes a presentation of disease that is underdiagnosed and heightens awareness of oncologists to this form of recurrence in nasopharyngeal carcinoma.

Clinical utility of polymerase chain reaction in the detection of Mycobacterium tuberculosis in different types of cutaneous tuberculosis and tuberculids

INTRODUCTION

The role of polymerase chain reaction (PCR) in the diagnosis of cutaneous tuberculosis in clinical practice has not been defined as no PCR assay has been tested in a large-scale clinical study. The objective of this study was to test the clinical utility of a PCR assay in the diagnosis of different types of cutaneous tuberculosis and tuberculids.

MATERIALS AND METHODS

Analysis of archival biopsy specimens by a nested PCR assay targeting IS6110 of Mycobacterium tuberculosis (M. tb) DNA was performed in a tertiary-care skin hospital in Singapore. PCR results were compared with cultures and concordance with final diagnosis. PATIENTS AND SPECIMENS: One hundred and nineteen skin biopsies from 105 patients comprising 58 cases of confirmed or highly probable cutaneous tuberculosis, ranging from multibacillary infections to paucibacillary forms and 47 cases of possible tuberculids were analysed. Twenty-four subjects with non-tuberculous granulomas and normal skin controls were included.

RESULTS

In 14 immunocompromised patients with multibacillary mycobacterial infections (AFB+ on biopsy), PCR was positive in 9 patients. Correlating PCR results with the final diagnosis, the PCR technique was 100% sensitive and specific in this group. In paucibacillary tuberculosis, PCR positivity rates were 55% for tuberculosis verrucosa cutis (38 cases) and 60% for lupus vulgaris (5 cases). When confirmed cases of tuberculosis were considered, the overall sensitivity was 73%. In 26 cases of erythema induratum, PCR was positive in 54% and correlated with a documented response to anti-tuberculous treatment in 80%.

CONCLUSIONS

The use of PCR in the routine diagnostic panel for cutaneous tuberculosis should take into consideration the differential sensitivities for different clinical types. In the setting of an immunocompromised patient with AFB+ lesions, PCR has a definite role in rapid diagnosis and in differentiating atypical mycobacterial infection from tuberculosis. Where paucibacillary tuberculosis is suspected, clinical decision should not be based on PCR results alone. In erythema induratum, we found some correlation between PCR results and response to anti-tuberculous therapy.

A retrospective study of melanocytic naevi at the National Skin Centre

INTRODUCTION

A retrospective study of melanocytic naevi was undertaken to assess the degree of clinico-pathological correlation and incidence of histological atypia.

MATERIALS AND METHODS

The case records from January to March 1996 of all patients with histologically diagnosed melanocytic naevi at the National Skin Centre were analysed.

RESULTS

Of the 240 lesions removed from 167 patients, the majority being women (111/167 patients), it was found that 55% (132/240) were correctly diagnosed. Fourteen per cent were mistaken for non-melanocytic lesions, namely skin tag, neurofibroma, syringoma cylindroma, epidermal naevus, naevus sebaceous and basal cell carcinoma. Most of the lesions were located on the cheeks and eyelids. Junctional naevi, followed by compound naevi were often missed. Histological dysplasia were seen in 7 naevi; 6 compound and 1 congenital naevi. There was a lack of clinico-pathological concordance in dysplastic naevi.

CONCLUSIONS

The clinico-pathological concordance of melanocytic naevi was high, with low incidence of atypia on histology.

Epidemiology of cutaneous lupus erythematosus in a tertiary referral centre in Singapore

The aim of this retrospective study was to investigate the epidemiology, yield of investigations and proportion of patients who develop systemic lupus erythematosus (SLE) among the subsets of cutaneous lupus erythematosus (LE) in the Singapore Asian population. One hundred and twenty-five patients were diagnosed with cutaneous LE on clinico-pathological correlation, of which 73 had discoid lupus erythematosus (DLE), eight had subacute cutaneous LE (SCLE), 22 had acute LE lesions and the remainder had other less common forms of cutaneous LE. Histology was consistent with LE in 94.4% and suggestive in 4.8%. Direct immunofluorescence was positive in 61% of DLE, 86% of SCLE and 80% of acute LE cases. Antinuclear antibody (ANA) was present in the majority of acute LE (85%) and SCLE (88%) but only in 25% of DLE. Eight patients (11%) presenting with DLE had definite SLE at first presentation and two (2.7%) subsequently several months later. Of these patients, six had only mucocutaneous and serological criteria but two had major organ involvement. Five SCLE patients (63%) fulfilled the criteria for SLE, including two with major organ involvement.

The genome structure of kyuri green mottle mosaic tobamovirus and its comparison with that of cucumber green mottle mosaic tobamovirus

The genome of the Y strain of kyuri green mottle mosaic virus (KGMMV-Y) has been completely sequenced. Its genomic structure and sequence show it to be a typical tobamovirus, that is closest to, but distinct from, that of cucumber green mottle mosaic tobamovirus (CGMMV). The genomic sequence of KGMMV-Y was compared in detail with that of the SH strain of CGMMV. The sequences of their 5'- and 3'-untranslated regions were 74% and 63% identical. The amino acid sequences of the shorter and longer (read through) RNA replicase components, movement protein (MP) and coat protein (CP) were 58, 58. 60 and 46% identical, respectively. The KGMMV-Y genome sequence was also compared partly to that of another strain of KGMMV, KGMMV-C. The CP sequences of KGMMV-Y and KGMMV-C differed by 20 amino acid residues, suggesting that their relationship is more distant than the relationship between CGMMV-SH and CGMMV-W whose CP sequences are identical. The MPs of KGMMV-Y and KGMMV-C, however, differ only by one amino acid residue, although three amino acid substitutions are present in the MPs between CGMMV-SH and CGMMV-W. Two long stretches, one in the RNA replicase and the other in the MP, were highly conserved in KGMMV and CGMMV.

A case report of erythema induratum of Bazin's disease

INTRODUCTION

Erythema induratum remains one of the rarely encountered tuberculid although tuberculosis is known to be endemic in the developing countries. We report a case of erythema induratum recently encountered in our centre.

CLINICAL FEATURE

Clinically, erythema induratum typically manifests as ulcerative and indurated lesions on the lower limbs, especially the calves. TREATMENT OUTCOME: The patient responded well to a course of anti-tuberculous therapy with marked resolution of the lesions, suggesting the aetiological role of Mycobacterium tuberculosis in this condition.

CONCLUSION

A short review of the distinguishing features of erythema induratum, the associated classical histological spectrum and the usefulness of polymerase chain reaction in the diagnosis of erythema induratum is given. A search for active foci of tuberculosis is advocated in all cases.

Tetracycline and nicotinamide for the treatment of bullous pemphigoid: our experience in Singapore

AIM OF STUDY

To study the efficacy of tetracycline (or doxycycline) and nicotinamide in the treatment of less extensive bullous pemphigoid.

METHODS

An open trial of 11 patients with bullous pemphigoid. Treatment was initiated with tetracycline 1.5-2 g/day and nicotinamide 1.5-2 g/day and gradually tapered down. Doxycycline was substituted for tetracycline in patients who could not tolerate tetracycline due to gastrointestinal side effects or headache.

RESULTS

6 out of 11 patients achieved complete response (> 90% decrease in lesions) while another 2 had partial response (50-90% decrease in lesions).

CONCLUSION

Tetracycline/doxycycline and nicotinamide is a useful alternative treatment for localized bullous pemphigoid, especially in those whose concurrent medical illnesses preclude the use of systemic corticosteroids.

Restoration of prehension with the double free muscle technique following complete avulsion of the brachial plexus. Indications and long-term results

BACKGROUND

Recent interest in reconstruction of the upper limb following brachial plexus injuries has focused on the restoration of prehension following complete avulsion of the brachial plexus.

METHODS

Double free muscle transfer was performed in patients who had complete avulsion of the brachial plexus. After initial exploration of the brachial plexus and (if possible) repair of the fifth cervical nerve root, the first free muscle, used to restore elbow flexion and finger extension, is transferred and reinnervated by the spinal accessory nerve. The second free muscle, transferred to restore finger flexion, is reinnervated by the fifth and sixth intercostal nerves. The motor branch of the triceps brachii is reinnervated by the third and fourth intercostal nerves to restore elbow extension. Hand sensibility is restored by suturing of the sensory rami of the intercostal nerves to the median nerve or the ulnar nerve component of the medial cord. Secondary reconstructive procedures, such as arthrodesis of the carpometacarpal joint of the thumb, shoulder arthrodesis, and tenolysis of the transferred muscle and the distal tendons, may be required to improve the functional outcome.

RESULTS

The early results were evaluated in thirty-two patients who had had reconstruction with use of the double free muscle procedure. Twenty-six of these patients were followed for at least twenty-four months (mean duration, thirty-nine months) after the second free muscle transfer, and they were assessed with regard to the long-term outcome as well. Satisfactory (excellent or good) elbow flexion was restored in twenty-five (96 percent) of the twenty-six patients and satisfactory prehension (more than 30 degrees of total active motion of the fingers), in seventeen (65 percent). Fourteen patients (54 percent) could position the hand in space, negating simultaneous flexion of the elbow, while moving the fingers at least 30 degrees and could use the reconstructed hand for activities requiring the use of two hands, such as holding a bottle while opening a cap and lifting a heavy object. The results were analyzed to identify factors affecting the outcome.

CONCLUSIONS

The double free muscle procedure can provide reliable and useful prehensile function for patients with complete avulsion of the brachial plexus.

The Penaeus monodon Chitinase 1 Gene Is Differentially Expressed in the Hepatopancreas During the Molt Cycle

We have isolated a full-length chitinase complementary DNA from the tiger shrimp Penaeus monodon that encodes a 621 amino acid protein possessing the functional domains of the chitinase protein family. The Penaeus monodon chitinase 1 (PmChi-1) gene product is 81.8% identical to a chitinase 1 protein expressed in the hepatopancreas of Penaeus japonicus. Analysis by reverse transcription-polymerase chain reaction (RT-PCR) indicates that PmChi-1 messenger RNA is detectable in the hepatopancreas and the gut. PmChi-1 expression during the molt cycle fluctuates markedly, with lowest mRNA levels at stages A(1), C, and D(3); there is a dramatic increase in transcript abundance at the D(2) stage. Using the same tissues and molt stages, RT-PCR analyses of genes encoding other digestive enzymes (trypsin, chymotrypsin, and cathepsin L), a muscle structural protein (tropomyosin II), and housekeeping proteins (elongation factor II and GTP-binding protein) indicate that PmChi-1 is expressed in a distinct tissue-specific and stage-specific manner. The other digestive enzyme genes are expressed in a similar spatiotemporal pattern, but none exhibited a dramatic increase in transcript abundance at stage D(2). Increased expression of PmChi-1 at D(2) suggests that hepatopancreas-expressed chitinase is involved in the degradation of endogenous chitin in the gut peritrophic membrane prior to molting.

Nuclear matrix attachment regions of human papillomavirus type 16 repress or activate the E6 promoter, depending on the physical state of the viral DNA

Two nuclear matrix attachment regions (MARs) bracket a 550-bp segment of the long control region (LCR) containing the epithelial cell-specific enhancer and the E6 promoter of human papillomavirus type 16 (HPV-16). One of these MARs is located in the 5' third of the LCR (5'-LCR-MAR); the other lies within the E6 gene (E6-MAR). To study their function, we linked these MARs in various natural or artificial permutations to a chimeric gene consisting of the HPV-16 enhancer-promoter segment and a reporter gene. In transient transfections of HeLa cells, the presence of either of these two MARs strongly represses reporter gene expression. In contrast to this, but similar to the published behavior of cellular MARs, reporter gene expression is stimulated strongly by the E6-MAR and moderately by the 5'-LCR-MAR in stable transfectants of HeLa or C33A cells. To search for binding sites of soluble nuclear proteins which may be responsible for repression during transient transfections, we performed electrophoretic mobility shift assays (EMSAs) of overlapping oligonucleotides that represented all sequences of these two MARs. Both MARs contain multiple sites for two strongly binding proteins and weak binding sites for additional factors. The strongest complex, with at least five binding sites in each MAR, is generated by the CCAAT displacement factor (CDP)/Cut, as judged by biochemical purification, by EMSAs with competing oligonucleotides and with anti-CDP/Cut oligonucleotides, and by mutations. CDP/Cut, a repressor that is down-regulated during differentiation, apparently represses HPV-16 transcription in undifferentiated epithelials cells and in HeLa cells, which are rich in CDP/Cut. In analogy to poorly understood mechanisms acting on cellular MARs, activation after physical linkage to chromosomal DNA may result from competition between the nuclear matrix and CDP/Cut. Our observations show that cis-responsive elements that regulate the HPV-16 E6 promoter are tightly clustered over at least 1.3 kb and occur throughout the E6 gene. HPV-16 MARs are context dependent transcriptional enhancers, and activated expression of HPV-16 oncogenes dependent on chromosomal integration may positively select tumorigenic cells during the multistep etiology of cervical cancer.

Hypergammaglobulinaemic purpura presenting as reticulate purpura

Hypergammaglobulinaemic purpura, first described by Waldenstrom, is a rare skin disease. The essential features are the presence of purpura with polyclonal hypergammaglobulinaemia. We describe a case of hypergammaglobulinaemic purpura occurring in a Chinese man with reticulate purpura and haemorrhagic blisters.

Cutaneous Rosai-Dorfman disease presenting as pustular and acneiform lesions

We report 2 cases of cutaneous Rosai-Dorfman disease (CRD) presenting with pustular and acneiform lesions. To our knowledge, these are the first reports of CRD presenting in this pattern. One patient had spontaneous resolution of the lesions, whereas the other was treated with cryotherapy with clinical improvement. We present a review of the literature regarding CRD and highlight the benign nature of this condition.

Once-daily intraperitoneal gentamicin is effective therapy for gram-negative CAPD peritonitis

OBJECTIVE

To report our 3-year experience with the use of once-daily intraperitoneal (IP) gentamicin in the treatment of gram-negative continuous ambulatory peritoneal dialysis (CAPD) peritonitis.

DESIGN

A prospective cohort study in prevalent CAPD patients.

SETTING

A tertiary care institution.

PATIENTS

All CAPD patients who presented with new episodes of peritonitis were studied. At presentation with peritonitis, IP vancomycin and gentamicin were administered as empirical therapy. IP gentamicin was given at a single daily dose of 40 mg/2 L in the overnight bag. The antimicrobial agents were reviewed when the culture results became available. Intraperitoneal ceftazidime was added for the treatment of pseudomonas peritonitis.

MAIN OUTCOME MEASURES

Results of microbiological cultures and clinical outcomes of peritonitis were analyzed.

RESULTS

Over a 36-month period, 190 episodes of peritonitis were recorded, of which 62/190 episodes (32.6%) isolated gram-negative organisms. The gram-negative organisms isolated were Escherichia coli, 15/62 episodes (24.1%); Pseudomonas aeruginosa, 12/62 episodes (19.4%); Acinetobacter spp, 12/62 episodes (19.4%); Klebsiella spp, 10/62 episodes (16.1%); and others, 13/62 episodes (21.0%). The overall treatment success rate was 66.1%. The treatment success rates were 74.0% if pseudomonas infections were excluded, 76.1% if gentamicin-resistant pathogens were excluded, and 80.5% if both pseudomonas infections and gentamicin-resistant pathogens were excluded.

CONCLUSIONS

Once-daily IP gentamicin appears to be effective in the treatment of gram-negative CAPD peritonitis.

Detection of Mycobacterium tuberculosis DNA using polymerase chain reaction in cutaneous tuberculosis and tuberculids

BACKGROUND

The objective of this study was to explore the role of the polymerase chain reaction (PCR) fo the detection of Mycobacterium tuberculosis DNA as a diagnostic aid in cutaneous tuberculosis using routinely processed skin biopsy specimens.

METHODS AND RESULTS

A wide range of clinical specimens representing different forms of cutaneous tuberculosis and so-called tuberculids were studied. A sensitive and specific PCR assay targeting the sequence IS6110 of Mycobacterium tuberculosis complex was used. The specimens were categorized as follows. 1 Acid-fast bacilli (AFB) positive on biopsy (nine specimens from seven patients who were immunocompromised). PCR was positive in five specimens. Of these, one specimen was culture positive and three specimens were culture negative. 2 AFB negative on biopsy: (a) tuberculosis verrucosa cutis (23 specimens); (b) lupus vulgaris (three specimens); (c) cutaneous tuberculosis clinically suspected (six specimens). PCR was negative in all specimens. 3 Tuberculids.' (a) erythema induratum/nodular vasculitis (20 specimens); (b) papulonecrotic tuberculid (two specimens); (c) erythema nodosum (20 specimens). PCR was negative in all specimens.

CONCLUSIONS

The role of PCR in clinical dermatologic practice, at this stage, may be in differentiating between cutaneous tuberculosis and atypical mycobacterial infections in the context of an immunocompromised patient where AFB can be demonstrated on biopsy and cultures may be negative. In this clinical situation, PCR allows the prompt diagnosis and early institution of appropriate therapy. We have not found PCR to be a useful complement to the clinical and histologic diagnosis of "paucibacillary" forms of cutaneous tuberculosis.

The treatment of unrelated disorders in patients with chronic medical diseases

BACKGROUND

Patients can have several illnesses concurrently, yet some of these diseases may be neglected if one problem consumes attention. We conducted a population-based analysis in Ontario, Canada - where universal health insurance is provided - to determine whether unrelated disorders are less likely to be treated in patients with chronic diseases.

METHODS

We studied the 1,344,145 residents of Ontario in 1995 who were 65 or older and eligible to receive prescription medications free of charge as part of the Ontario Drug Benefit program. Patients with diabetes mellitus were identified by prescriptions for insulin, pulmonary emphysema by prescriptions for ipratropium bromide, and psychotic syndromes by prescriptions for haloperidol. For each chronic disease, we selected an unrelated treatment: estrogen-replacement therapy for patients with diabetes mellitus, lipid-lowering medications for those with pulmonary emphysema, and medical treatment of arthritis for those with psychotic syndromes.

RESULTS

The 30,669 patients with diabetes mellitus were less likely to receive estrogen-replacement therapy than the other subjects in the study (2.4 percent vs. 5.9 percent, P<0.001). The disease was associated with a 60 percent reduction in the odds of estrogen treatment (odds ratio, 0.40; 95 percent confidence interval, 0.37 to 0.43). Findings were similar for the 56,779 patients with pulmonary emphysema, who were less likely to receive lipid-lowering medications (odds ratio, 0.69; 95 percent confidence interval, 0.67 to 0.72; P<0.001), and the 17,336 patients with psychotic syndromes, who were less likely to receive medical treatments for arthritis (odds ratio, 0.59; 95 percent confidence interval, 0.57 to 0.62; P<0.001).

CONCLUSIONS

In patients 65 or older who have chronic medical diseases and who receive prescription medications free of charge, unrelated disorders are undertreated. Clinicians caring for patients with chronic diseases should remain alert to other disorders and minimize the number of missed opportunities for treating them.

Nuclear matrix attachment regions of human papillomavirus type 16 point toward conservation of these genomic elements in all genital papillomaviruses

The gene functions, transcriptional regulation, and genome replication of human papillomaviruses (HPVs) have been extensively studied. Thus far, however, there has been little research on the organization of HPV genomes in the nuclei of infected cells. As a first step to understand how chromatin and suprachromatin structures may modulate the life cycles of these viruses, we have identified and mapped interactions of HPV DNAs with the nuclear matrix. The endogenous genomes of HPV type 16 (HPV-16) which are present in SiHa, HPKI, and HPKII cells, adhere in vivo to the nuclear matrixes of these cell lines. A tight association with the nuclear matrix in vivo may be common to all genital HPV types, as the genomes of HPV-11, HPV-16, HPV-18, and HPV-33 showed high affinity in vitro to preparations of the nuclear matrix of C33A cells, as did the well-known nuclear matrix attachment region (MAR) of the cellular beta interferon gene. Affinity to the nuclear matrix is not evenly spread over the HPV-16 genome. Five genomic segments have strong MAR properties, while the other parts of the genome have low or no affinity. Some of the five MARs correlate with known cis-responsive elements: a strong MAR lies in the 5' segment of the long control region (LCR), and another one lies in the E6 gene, flanking the HPV enhancer, the replication origin, and the E6 promoter. The strongest MAR coincides with the E5 gene and the early-late intergenic region. Weak MAR activity is present in the E1 and E2 genes and in the 3' part of L2. The in vitro map of MAR activity appears to reflect MAR properties in vivo, as we found for two selected fragments with and without MAR activity. As is typical for many MARs, the two segments with highest affinity, namely, the 5' LCR and the early-late intergenic region, have an extraordinarily high A-T content (up to 85%). It is likely that these MARs have specific functions in the viral life cycle, as MARs predicted by nucleotide sequence analysis, patterns of A-T content, transcription factor YY1 binding sites, and likely topoisomerase II cleavage sites are conserved in similar positions throughout all genital HPVs.

An unusual mitochondrial atp9-rpl16 cotranscript found in the maternal distorted leaf mutant of Arabidopsis thaliana: implication of GUG as an initiation codon in plant mitochondria

Properties of an unusual atp9-rpl16 cotranscript preferentially found in the maternal distorted leaf mutant of Arabidopsis thaliana, which had arisen from a genetic cross between chloroplast mutator and wild-type plants, were examined. Analysis of RNA editing of this cotranscript showed that one editing event in the rpl16 coding region created a UGA stop codon. This raises a possibility that a downstream GUG codon can serve as an initiation codon for rpl16.

Growth factor-dependent phosphoinositide signalling

A wide variety of messages, in the form of diffusible growth factors, hormones and cytokines, are carried throughout multicellular organisms to coordinate important physiological properties of target cells, such as proliferation, differentiation, migration, apoptosis and metabolism. Most messengers bind to cognate receptors on target cells, which initiate a characteristic cascade of reactions within the cell, ultimately leading to the desired response. The cellular response is defined by the combination of signalling components whose individual activity depends upon the number and type of surface receptors. Consequently the responses of different cell types to one or more stimuli can be quite disparate. A molecular understanding of the signalling pathways employed by each type of receptor therefore underlies the ability to rationalize many cellular functions and to correct disfunctions. As a well studied example of the primary signalling events that take place on the cytoplasmic leaflet of the plasma membrane following receptor activation, we will discuss how the widely expressed receptor for epidermal growth factor (EGF) causes the phosphorylation and hydrolysis of a signalling precursor, the membrane lipid phosphatidylinositol. This paradigm will be used to illustrate certain general principles of signalling, including formation of multienzyme complexes, compartmentation of second messengers and intermediates, and cross-talk between different signalling pathways.

YY1 represses human papillomavirus type 16 transcription by quenching AP-1 activity

YY1 is a multifunctional transcription factor that has been shown to regulate the expression of a number of cellular and viral genes, including the human papillomavirus (HPV) oncogenes E6 and E7. In this study, we have analyzed the YY1-mediated repression of the HPV type 16 (HPV-16) E6-E7 promoter. A systematic analysis to identify YY1 sites present in the HPV-16 long control region showed that of 30 potential YY1 binding motifs, 24 bound purified recombinant YY1 protein, but only 10 of these were able to bind YY1 when nuclear extracts of HeLa cells were used. Of these, only a cluster of five sites, located in the vicinity of an AP-1 motif, were found to be responsible for repressing the HPV-16 P97 promoter. All five sites were required for repression, the mutation of any one site giving rise to a four- to sixfold increase in transcriptional activity. The target for YY1-mediated repression was identified as being a highly conserved AP-1 site, and we propose that AP-1 may represent a common target for YY1 repression. We also provide data demonstrating that YY1 can bind the transcriptional coactivator CREB-binding protein and propose a potentially novel mechanism by which YY1 represses AP-1 activity as a result of this YY1-CREB-binding protein interaction.

Skin cancers at Tertiary Referral Skin Hospital in Singapore

BACKGROUND

Skin cancer is the seventh most common cancer in Singapore. This study was performed to determine the pattern of skin cancers seen in a tertiary referral skin hospital.

METHODS

Histologically confirmed skin cancers, seen between 1980 and 1991, were analyzed according to age, sex, race, site, and presence/absence of preexisting skin conditions.

RESULTS

Of a total of 520 patients, the commonest skin cancer was basal cell carcinoma (BCC) (36.5%), followed by squamous cell carcinoma (SCC) (24.4%), Bowen's disease (16.7%), and mycosis fungoides (9.0%). Malignant melanomas (2.7%) were rare. The sharp increase (26.2%) in BCC in the recent 3 years was largely contributed by a fivefold increase of non-resident Caucasian patients with BCC. All types of skin cancers were more common in Chinese (78.1%) and less frequent in the more pigmented races (9.4%). The men to women ratio was 1.72:1. The peak age distribution was in the 51-70-year group, with the exception of mycosis fungoides (31-50 years). The commonest site involved in BCC was the head and neck (67.0%) and in Bowen's disease the trunk (33.3%). Squamous cell carcinoma was found on the head and neck and the lower extremities with equal frequency (29.3%) and 46.2% of all SCC on the lower extremities occurred in leprosy patients with chronic trophic ulcers. Of patients with Bowen's disease involving the nonsunexposed parts (trunk and upper extremities), 42.6% had probable arsenic exposure evident either from the history or clinical examination. Malignant melanomas were commonly located on the foot (71.4%).

CONCLUSIONS

The commonest skin cancers seen were BCC, SCC, Bowen's disease, and mycosis fungoides. There were differences in the site distribution of SCC, Bowen's disease, and malignant melanomas in our study when compared to studies in Caucasians.

Cadmium hazard in silver brazing

This study evaluates the usage of cadmium-containing silver brazing alloys in Singapore and the potential cadmium hazard from its use. Of the 137 factories which responded to the survey questionnaire, only 28 (20.4%) carried out brazing. Of these, only 7 factories used cadmium-containing filler alloys. One hundred and six out of 123 workers from one of these factories had cadmium-in-blood concentrations exceeding 10 mcg/l. Thirty-one (29.2%) of the workers with excessive cadmium absorption had urinary beta-2 microglobulin levels exceeding 28 mcg/g creat. Workers in the other factories who were intermittently exposed had cadmium-in-blood concentrations of 10 mcg/l and below.

Upright tilt table testing in the evaluation of syncope

OBJECTIVES

To review our experience with the upright tilt table test for the diagnosis of vasovagal syncope in a group of unselected patients with a history of syncope or presyncope.

METHODS

179 patients with a history of syncope or presyncope were subjected to upright tilt test. After carotid sinus massage to exclude carotid sinus hypersensitivity, the patients were tilted on a motorised tilt table with footplate support to an angle of sixty to seventy degrees for thirty minutes. If syncope was not induced, isoprenaline was then infused for a further fifteen minutes. A positive response was defined as fulfilling at least two out of three criteria: (i) syncope or presyncope similar to the spontaneous episodes of syncope, (ii) relative slowing of the heart rate at the onset of symptoms, (iii) drop of systolic pressure to less than 90 mmHg or by more than 50 mmHg.

STATISTICAL METHODS

Continuous variables are expressed as mean values +/- one standard deviation and analysed for statistical significance by the unpaired Student's t-test. Chi-squared test with continuity correction was used for dichotomous variables.

RESULTS

Ninety-four patients (53%) were positive for vasovagal syncope. Fourteen patients (8%) were positive at baseline tilt. An additional 80 patients (45%) were positive with the use of isoprenaline. Ten percent of the positive responses were purely cardioinhibitory, 10% purely vasodepressor and 80% mixed. The commonest cardiac rhythm during a positive response was junctional rhythm (46%) followed by sinus rhythm (44%). Sinus arrest with ventricular standstill occurred in only 5%. Accelerated idioventricular rhythm, 2:1 atrioventricular block and ventricular bigeminy accounted for the remaining 5%.

CONCLUSION

The upright tilt table test is useful for the diagnosis of vasovagal syncope.

Cryosubstitution technique reveals new morphology of flavivirus-induced structures

Cryotechniques in combination with electron microscopy were used in an attempt to obtain more precise morphological details of flavivirus-induced structures. From conventional chemical fixation procedure, proliferation of endoplasmic reticulum, formation of microtubule paracrystals and clusters of smooth membrane vesicles (with 'thread-like' enclosures) were observed. These induced changes are typical for flavivirus infections. The images obtained from cryosections were disappointing as the structures were not well preserved. On the other hand, cryosubstituted-infected cells gave revealing images of the virus-induced structures. The most obvious difference between the cryosubstituted and chemical fixed processes was on the morphology of the 'thread-like' structure. The 'thread-like' structures instead appeared as dense cores. The morphology of the virus particles was also better defined. The envelope of the virus appeared clearly differentiated from the nucleocapsid. The most important finding was that the cryosubstituted technique was able to preserve the structures of the flavivirus nucleocapsids which so far has not been convincing reported with chemical processing.

The human papillomavirus type 16 E2 transcription factor binds with low cooperativity to two flanking sites and represses the E6 promoter through displacement of Sp1 and TFIID

The E6 promoters of all genital human papillomaviruses have a characteristic alignment of transcription factor binding sites. Activation of the basic transcription complex at the TATA box depends upon a sequence-aberrant Sp1 site. Repression of E6 promoters is achieved by two binding sites for the viral E2 protein positioned between the Sp1 site and the TATA box. We have purified the human papillomavirus type 16 E2 protein after expression in Escherichia coli and studied its binding and repression properties with oligonucleotides representing the homologous promoter sequences. A Kd value of 3 x 10(-10) M indicated binding properties expected for a native protein. We found low cooperativity in the binding of two E2 dimers to flanking sites, both when these sites were separated by 3 nucleotides, as in the natural promoter, and when they were further apart. E2 protein, bound close to the distal Sp1 site, displaced the Sp1 factor even when the aberrant sequence was replaced by a typical Sp1 core recognition site. The high affinity of E2 protein for its binding site even led to Sp1 displacement at concentrations of E2 protein nearly 2 orders of magnitude lower than those of Sp1. Functional analyses of mutated E6 promoter sequences showed repression by this distal E2 binding site in the complete absence of binding to the proximal E2 binding site. From our findings and observations published by others, we conclude that each of the E2 binding sites in the E6 promoter of genital human papillomaviruses plays a separate role by displacing the transcription factors Sp1 and TFIID.

Altered p53 expression and epidermal cell proliferation is seen in vulval lichen sclerosus

Aberrant p53 immunoreactivity has been found in skin pre-malignancies and dysplasias such as Bowen's disease and actinic keratoses. Vulval lichen sclerosus (LS) has been reported to be pre-malignant, with an association of vulval carcinoma in 3% to 6% of patients. In contrast, non-genital LS appears to have no malignant potential. In this immunocytochemical study, we investigated p53 expression in 10 cases of histologically proven vulval LS and 9 cases of non-genital LS using the murine monoclonal antibody Do-1 raised against recombinant human p53 which reacts with both wild-type and mutant p53. None of the vulval specimens had epithelial dysplasia or malignancy. Normal vulval (7 cases) and non-genital skin (5 cases) were used as tissue controls, respectively. The cell proliferation index was also studied using the MIB 1 monoclonal antibody which detects the cell-cycle associated Ki-67 antigen. The technique of microwave irradiation for antigen unmasking was employed on formalin-fixed and paraffin-embedded tissues. There was a significant increase in p53 immunoreactivity in vulval LS (32.13 +/- 15.11 epidermal cells per 100 basal cells) compared to normal vulval skin (7.52 +/- 5.04 epidermal cells per 100 basal cells) (p < 0.001), whereas the MIB 1 labelling index was lower in vulval LS (39.45 +/- 15.88 epidermal cells per 100 basal cells) than in normal controls (86.26 +/- 32.31 epidermal cells per 100 basal cells) (0.001 < p < 0.01). In contrast, there was no significant difference in p53 immunoreactivity or MIB 1 labelling index between non-genital LS and normal controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficient and rapid affinity purification of proteins using recombinant fusion proteases

In the affinity purification of recombinant fusion proteins, the rate-limiting step is usually the efficient proteolytic cleavage and removal of the affinity tail and the protease from the purified recombinant protein. We have developed a rapid, convenient and efficient method of affinity purification which can overcome this limitation. In one example of the method, the protease 3C from a picornavirus (3Cpro), which cleaves specific sequences containing a minimum of 6-7 amino acids, has been expressed as a fusion with glutathione S-transferase. The resultant recombinant 'fusion protease' cleaves fusion proteins bearing (from the amino-terminus) the same affinity tail as the fusion protease, a 3Cpro cleavage recognition site, and the recombinant protein of interest. The recombinant protein is purified in a single chromatographic step which removes both the affinity tail and the fusion protease. The advantages over existing methods include much improved specificity of proteolytic cleavage, complete removal of the protease and the affinity tail in one step, and the option of adding any desired amount of fusion protease to ensure efficient cleavage. The potential flexibility of the method is shown by the use of various affinity tails and alternative fusion proteases.

Immunological characterisation of the lichen planus infiltrate using monoclonal antibodies

The immunological typing of cell populations in the skin biopsies of 20 cases of histologically proven lichen planus was done using monoclonal antibodies. The Avidin-Biotin-Complex immunoperoxidase technique was used. A predominance of T-helper/inducer cells in the dermal infiltrate was observed by a semiquantitative analysis. T-suppressor/cytotoxic cells and Langerhans cells were increased compared to eczema lesions. A comparison of the staining of Langerhans cells using monoclonal antibodies and the S100 protein stain showed that more Langerhans cells could be identified with the CD1 monoclonal antibody. The type of infiltrate did not correlate with the duration of disease. Direct immunofluorescence staining demonstrated fibrinogen at the dermo-epidermal junction and/or colloid bodies in the upper dermis. The immunophenotyping and immunofluorescence pattern in local cases of lichen planus are similar to previous reports from other countries. An interesting finding was the unexplained disproportionate predominance of Indians in the study cohort.

During negative regulation of the human papillomavirus-16 E6 promoter, the viral E2 protein can displace Sp1 from a proximal promoter element

The principal early promoter of human papillomaviruses (HPVs), designated P97 in the case of HPV-16, contains four characteristically aligned cis-responsive elements, namely one binding site for Sp1, two for the viral E2 proteins, and the TATA box. The Sp1 binding site is needed to mediate activation of P97 by the remote epithelial-specific enhancer, and the two E2 binding sites contribute to a negative feedback-loop of viral gene expression. The Sp1 consensus motif and the TATA-box distal E2 binding site are spaced in all genital papillomaviruses by a single nucleotide. We show here that at physiological concentrations, the binding of E2 proteins and Sp1 are mutually exclusive events, since a bandshift analysis with nuclear extracts from ID13, a mouse cell line transformed by BPV-1, showed only the E2 or the Sp1 bandshift, but no complex indicative of the concomitant binding of both factors. Increasing concentrations of in vitro translated E2 protein compete efficiently with the Sp1 factor for binding to an oligonucleotide containing both binding sites. Interference between Sp1 and E2 protein binding is apparently relevant for P97 repression in vivo, since a mutational analysis revealed that both E2 binding sites are necessary for negative transcriptional regulation: Alone, neither the distal site, where E2 protein can induce Sp1 displacement, nor the proximal site, where E2 protein interferes with formation and function of the pre-initiation complex, have a significant effect, but two functional E2 binding sites lead to repression of P97.

Synaptic junctions between sympathetic axon terminals and pinealocytes in the monkey Macaca fascicularis

The distribution of axon terminals in the pineal gland of monkeys was studied by electron microscopy. Numerous terminals bearing small pleomorphic agranular and dense-cored vesicles were localized in the perivascular space and among the pinealocytes in the parenchyma in normal monkeys. Following bilateral superior cervical ganglionectomy, they underwent degenerative changes, including the accumulation of glycogen masses, appearance of dense residual bodies and the displacement of synaptic vesicles. Some of these degenerating terminals showed synaptic contacts with the cell bodies of pinealocytes. At the synaptic junction the postsynaptic membrane was thickened asymmetrically. Examples of synaptic contacts were most frequently observed in 5 and 7 days postoperative animals. In the longer surviving (30 days) monkey, most of the axon terminals showed round agranular vesicles, and they were mainly presynaptic to the intrapineal ganglion cells with some of the pinealocytes. They remained structurally unchanged following the resection of both the superior cervical ganglia. A few axon terminals containing small dense-cored vesicles appeared to have survived the initial insult, but some of their vesicles appeared swollen 30 days after the operation. It is concluded from this study that some of the pinealocytes are under the influence by the postganglionic neurons in the superior cervical ganglia through direct synaptic contacts. The intrapineal ganglion cells are postsynaptic to fibres originating exclusively from the central nervous system. Some of these fibres, however, may be presynaptic directly to pinealocytes.