Equine herpesvirus 1 glycoprotein D expressed in E. coli provides partial protection against equine herpesvirus infection in mice and elicits virus-neutralizing antibodies in the horse.

The envelope glycoprotein D of EHV-1 (EHV-1 gD) is essential for virus infectivity and entry of virus into cells and is a potent inducer of virus-neutralizing antibody. In this study, truncated EHV-1 gD (gDt) was expressed with a C-terminal hexahistidine tag in E. coli using a pET vector. Western blot analysis using an anti-gD monoclonal antibody demonstrated the presence of gDt bands at 37.5, 36, 29.5 and 28 kDa. The immunogenicity and protective efficacy of partially purified gDt was compared with gD expressed in insect cells by a recombinant baculovirus (Bac gD) using a BALB/c mouse model of EHV-1 respiratory infection. The proteins were also compared in a prime-boost protocol following an initial inoculation with gD DNA. gDt elicited similar levels of gD-specific antibody and neutralizing antibody compared with Bac gD and also provided a similar level of protection against EHV-1 challenge in mice. Inoculation of horses with gDt elicited EHV-1 gD-specific antibodies including virus-neutralizing antibody, suggesting that despite the lack of glycosylation, E. coli may be a useful vehicle for large scale production of EHV-1 gD for vaccine studies.

Inoculation with DNA encoding the glycoprotein gp2 reduces severity of equine herpesvirus 1 infection in a mouse respiratory model.

The envelope glycoprotein 2 (gp2) of equine herpesvirus 1 (EHV-1) has no known homologue in other herpesviruses with the exception of some equid alphaherpesviruses. In order to investigate the potential of gp2 as a vaccine antigen, expression vectors were constructed to encode full-length gp2, a truncated version lacking the membrane anchor, and the C-terminal region. Intramuscular inoculation of mice with these DNA constructs induced neutralizing antibody against EHV-1 and, following intranasal challenge with EHV-1, mice inoculated with any of the gp2 DNA constructs cleared virus more rapidly from their lungs than control mice. The rate of clearance was comparable to that for glycoprotein D DNA, indicating gp2 as a potential antigen for inclusion in a subunit vaccine.

Esophageal squamous metaplasia: nudging the esophageal carcinoma morphogenetic paradigm.

The concept regarding esophageal squamous metaplasia, its existence, origin and the role it plays in the etiology of esophageal carcinoma, needs some urgent attention. Explanations regarding the presence of metaplastic squamous epithelial cells on esophageal smears, from asymptomatic high-risk patients undergoing screening for esophageal carcinoma, are difficult to find. The presence of squamous metaplastic cells on smears from the esophagus collected by us since 1983, from rural Transkei populations, is a regular finding and warrants some discussion. Cellular material from the esophageal lumen is collected with a gelatine encapsulated sponge brush for cytological evaluation. Each full-length, 'blind' sampling procedure produces a mixture of single cells, sheets, small groups as well as microbiopsies. Some very well preserved and excellent examples of esophageal epithelium undergoing or in a state of squamous metaplasia are a regular find.

The C-terminal regions of the envelope glycoprotein gp2 of equine herpesviruses 1 and 4 are antigenically distinct.

The unusual mucin-like high molecular mass (Mr) glycoprotein 2 (gp2) has only been described in the equid alphaherpesviruses, among which there is considerable antigenic cross-reactivity. Equine herpesvirus 1 (EHV-1) gp2 is cleaved into a highly glycosylated N-terminal subunit and a 42 kDa C-terminal cleavage product. In order to investigate their antigenic recognition by horses naturally infected with EHV-1 and/or equine herpesvirus 4 (EHV-4), the C-terminal cleavage product and high Mr gp2 were affinity purified. Cross-reactivity between EHV-1 and EHV-4 was observed for the high Mr gp2 using Western blotting. In contrast only horses with antibodies to EHV-1 detected the 42 kDa EHV-1 gp2 C-terminal cleavage product. This phenomenon was evident in pooled sera from adult horses and also in foals that had demonstrated seroconversion due to EHV-1 infection. The results indicate that the C-terminal region of EHV-1 gp2 is antigenically distinct from that of EHV-4 gp2 and can be detected only after an EHV-1-specific immune response.

Automated identification of tubercle bacilli in sputum. A preliminary investigation.

OBJECTIVE: To use an automated method to detect tubercle bacilli in sputum specimens. STUDY DESIGN: Using fluorescence microscopy, tubercle bacilli were identified on auramine-stained sputum specimens. Images were then captured with a digital camera and enhanced through imaging processing techniques. The bacilli were recognized using neural network classifiers. RESULTS: This preliminary investigation demonstrated a sensitivity of 94.1% for the identification of individual bacilli. As there are usually fairly numerous tubercle bacilli in the sputum of patients with active pulmonary tuberculosis, the overall diagnostic accuracy of sputum smear-positive patients can be expected to be very high. CONCLUSION: Potential benefits of automated screening for TB bacilli are: rapid, accurate, inexpensive diagnosis; the ability to screen larger numbers of people; increased resources to monitor patients; and reduction in health risks to staff.

Nasopharyngeal lipoma--a rare clinico-pathological entity.

A lipoma situated within the posterior wall of the nasopharynx is reported. Only three lipomas of the nasopharynx in adults have previously been reported. The value of CT scan and cytology in making the preoperative diagnosis of a lipoma at this location is discussed.

Combined assessment (aspiration cytology and mammography) of clinically suspicious breast masses.

We examined the safety and utility of the combined assessment of aspiration cytology and mammography in 705 women who had clinically suspicious or malignant palpable breast masses. Histological assessment confirmed 176 benign and 529 malignant lesions. There were no incorrect (false positive) diagnoses made in the 176 benign masses when combined assessment was used (specificity 1.0; predictive value 0.86); in isolation, however, there was a false positive cytological diagnosis ('papillary carcinoma') and 3 false positive mammographic diagnoses. Benign disease (false negative) was incorrectly diagnosed by combined assessment in 4 of the 529 malignant masses (sensitivity 0.99; predictive value 0.98): cytological diagnoses were of fat necrosis (2) and benign cells on cytospin (1) and aspiration biopsy (1); mammographic diagnoses were of benign disease (2) and normality (2). Indeterminate ('atypical', 'suspicious') diagnoses were problematic and frequent (overall 223 (31.6%), malignant masses 137 (25.9%), benign masses 86 (48.9%); cytology 117 (16.6%), mammography 141 (20%). Thus, with the combined assessment of mammography and cytology in clinically suspicious breast masses, a decisive diagnosis was made in about two-thirds of cases allowing the safe commencement of therapy; the balance of patients required core or excision biopsy.

Towards a rational cervical cytology screening strategy. Case study of a peri-urban settlement.

OBJECTIVES: To assess cervical cytology screening activity in a peri-urban settlement near Cape Town, with a view to informing rational policy development. METHOD: Total and age-specific prevalence rates of women who had been screened, relative prevalence by age group of women who had not been screened, and yield of screening were estimated from cytopathology laboratory records and available demographic data. Age-specific prevalence rates among women who had been screened were compared with age at presentation with cervical cancer at the referral hospital. Attendance for colposcopy follow-up was assessed from colposcopy clinic records. RESULTS: The number of smears taken and the prevalence of women who had been screened peaked in the 20 - 24-year age group, and declined to low levels in those over the age of 40 years. The relative prevalence of those who had not had a smear exceeded 9 in all age groups over 39 years, compared with women of 20 - 24 years. Smears which showed signs of CIN III, malignancy or possible malignancy comprised 0.13%. Thirty-six per cent of women booked for colposcopy did not attend. CONCLUSIONS: Efficiency of screening could be improved by emphasising coverage of higher-risk age groups, e.g. women over the age of 30 years, and better follow-up.

The cytological recognition of African siderosis on bone smears.

Eight cases of African siderosis primarily recognized on cytological smears are presented and discussed. All the smears were obtained from Jamshidi needle biopsies of vertebral bodies. Six cases showed siderosis only, while a seventh showed two pathological processes on one slide, namely metastatic keratinizing squamous carcinoma and siderosis. The remaining case showed cytological evidence of tuberculosis and siderosis. All cases were histologically confirmed, an additional feature in two cases being osseous tuberculosis which was not evident on the cytological smears. A search of the literature failed to reveal any report on the cytological recognition of this disease, or its association with tuberculosis.

The significance of nuclear grooves and phagocytosis in the diagnosis of metastatic papillary carcinoma of the thyroid.

A 57-year-old patient presented with a lesion of the iliac bone. Cytological smears prepared from material aspirated from the lesion revealed cells with longitudinal nuclear grooves and haemosiderin within their cytoplasm. These observations led to a diagnosis of metastatic thyroid papillary carcinoma which was confirmed by histological examination.

Primary oesophageal rhabdomyosarcoma.

A case is presented of a rhabdomyosarcoma of the oesophagus with a description of the cytology, light microscopy, and immunocytochemical findings and a discussion of spindle cell tumours occurring at this site. Cytologically, large bizarre shaped pleomorphic cells were seen in which desmin was demonstrated in order to confirm the diagnosis after destaining a Papanicolaou stained slide and restaining it with antibody to desmin.

The changing incidence of cervical intra-epithelial neoplasia.

In order to determine whether the incidence of cervical intraepithelial neoplasia (CIN) was changing, statistics were obtained from the annual reports of the cytopathology laboratory at Groote Schuur Hospital, Cape Town, for the years 1979-1988 inclusive, and from the computerised records of the laboratory during 1987 and 1988. Analysis of 642,574 smears during the 10-year period showed an increase in incidence of human papillomavirus infection was noted. The follow-up of patients with CIN 3 was good. The peak incidence of CIN was in the 29-39 year age group. A high pick-up rate of CIN was noted in pregnant patients--10% had CIN 3. Smears from teenage patients, 78% of whom were pregnant, showed an alarmingly high incidence of atypical findings. The incidence of CIN is also high in the geriatric group of patients. These findings indicate that traditional teaching concerning cervical intra-epithelial neoplasia needs to be reviewed.

Helminths and protozoa as an incidental finding in cytology specimens.

This is a description of some helminths and protozoa found incidentally in routine cytology specimens submitted to this laboratory. Eight different organisms are described together with the case history for each patient. All the specimens were stained with Papanicolaou technique.

Giant cell hepatocellular carcinoma.

A terminal case of giant cell hepatocellular carcinoma, subsequent to Hepatitis B-associated macronodular cirrhosis is presented, illustrated and discussed. The uncommon finding of malignant ascites, in itself atypical of hepatocellular carcinoma, with an almost exclusive content of giant cells as the cellular component, was a feature of this unusual variant of hepatocellular carcinoma.

Fine-needle aspiration biopsy cytology of the breast. A review of the Groote Schuur Hospital experience.

The results of the first 1,500 cytological diagnoses of fine-needle breast aspirates performed at Groote Schuur Hospital Breast Clinic are compared with the histological diagnoses of Tru-cut and excision biopsies of the same lesions. A cytological diagnosis of malignant disease was made in 358 cases, 349 of which were confirmed histologically. The 10 false-positive and 1 false-negative diagnoses are discussed. The reliability of diagnosis in the first 500 cases is compared with that in the second and third 500 cases. There were no false-positive diagnoses in the last 500 cases, and only 3 in the second 500 cases compared with 7 in the first 500 cases. Similarly, the 1 false-negative diagnosis was made in the first 500 cases. The results confirm the reliability of fine-needle aspiration biopsy cytology as a diagnostic technique. The number of incorrect diagnoses decreases as experience with the technique increases.

Case for conservative management of selected fibro-adenomas of the breast.

To assess the safety of a conservative approach to fibro-adenoma of the breast we prospectively studied 321 women with this clinical diagnosis, and performed aspiration cytology and excision biopsy. There was histological confirmation of fibro-adenoma in 217 (68 per cent), the remainder having various benign conditions and 4 (1.3 per cent) had carcinoma. Aspiration cytology had a sensitivity of 87 per cent and a specificity of 76 per cent for fibro-adenoma. Three cases of carcinoma were identified cytologically and the fourth was regarded as suspicious. To estimate the risk of missing carcinoma we compared the annual frequency of carcinoma with fibro-adenoma in young women and found a ratio of 1:470 between 15 and 19 years, 1:133 between 20 and 24 years and 1:9 in the 25-29 age group. To assess patients' views on non-operative treatment of benign breast masses we asked 124 women, 10 days postoperatively, whether they preferred a conservative approach for a cytologically benign lump: 26 (21 per cent) opted for conservative management in the future and 8 (7 per cent) would have preferred conservatism rather than their recent excision. A conservative approach is safe for clinically and cytologically benign breast lumps in women under 25 years, but very few will accept it.

Surgical staging of gastric carcinoma: sources and consequences of error.

Macroscopic 'TNM' staging was performed during 78 consecutive operations for gastric carcinoma and compared with subsequent pathological staging. Surgical assessment was correct for tumour (T) in 60 per cent when depth of invasion was assessed, for nodes (N) in 61 per cent, for liver metastases (M) in 92 per cent but for all aspects in only 21 per cent. Curability (conservatively defined as T1-3, N0-1, M0) was correct in 8 of 18 patients thus assessed at surgery and incurability was pathologically correct in 58 of 60 patients. Despite inaccurate surgical staging, no patient was denied a resection although 10 patients had unduly radical procedures for their stage and 2 had inappropriately conservative procedures for their stage (but without evidence of residual disease). Staging errors did not jeopardize conventional surgical management substantially and use of intra-operative microscopic sampling of nodes would have improved surgical treatment only minimally.

Role of cul-de-sac aspiration cytology in the management and follow-up of patients with ovarian carcinoma. A preliminary report.

In a pilot study involving 44 patients on combined chemotherapy for epithelial ovarian carcinoma, cul-de-sac aspiration cytology was compared with second-look surgery in the evaluation of disease status. There was a 92% correlation. Our preliminary conclusion was that an aspirate from the cul-de-sac or peritoneal cavity can be obtained with ease and that if this finding is confirmed in a larger series now in progress, the procedure may in part replace second-look operations in the management of these patients.