Vertical transmission of sublethal granulovirus infection in the Indian meal moth, Plodia interpunctella.

Knowledge of the mechanisms of pathogen persistence in relation to fluctuations in host density is crucial to our understanding of disease dynamics. In the case of insect baculoviruses, which are typically transmitted horizontally via a lifestage that can persist outside the host, a key issue that remains to be elucidated is whether the virus can also be transmitted vertically as a sublethal infection. We show that RNA transcripts for the Plodia interpunctella GV granulin gene are present in a high proportion of P. interpunctella insects that survive virus challenge. Granulin is a late-expressed gene that is only transcribed after viral genome replication, its presence thus strongly indicates that viral genome replication has occurred. Almost all insects surviving the virus challenge tested positive for viral RNA in the larval and pupal stage. However, this proportion declined in the emerging adults. Granulin mRNA was also detected in both the ovaries and testes, which may represent a putative mechanism by which reduced fecundity in sublethally affected hosts might be manifested. RNA transcripts were also detected in 60-80% of second-generation larvae that were derived from mating surviving adults, but there was no difference between the sexes, with both males and females capable of transmitting a sublethal infection to their offspring. The data indicate that low-level persistent infection, with at least limited gene expression, can occur in P. interpunctella following survival of a granulovirus challenge. We believe that this is the first demonstration of a persistent, sublethal infection by a baculovirus to be initiated by a sublethal virus dose. We hypothesize that the 'latent' baculovirus infections frequently referred to in the literature may also be low level persistent, sublethal infections resulting from survival from initial baculovirus exposure.

Characterisation of a cysteine protease cDNA from Lolium multiflorum leaves and its expression during senescence and cytokinin treatment.

A cysteine protease cDNA clone (See1) highly homologous to barley aleurain was isolated from Lolium multiflorum leaves. During leaf senescence, expression of the See1 mRNA and protein was strongly enhanced. In dark-incubated leaf segments, cytokinin delayed senescence and reduced expression of both See1 mRNA and protein.

In vitro host range of Autographa californica nucleopolyhedrovirus recombinants lacking functional p35, iap1 or iap2.

We have examined the host range in different insect cell lines of Autographa californica nucleopolyhedrovirus (AcMNPV) recombinants lacking p35, iap1 or iap2. These genes encode, or are predicted to encode, anti-apoptotic proteins. Abrogation of p35 reduced the ability of AcMNPV to replicate in permissive cell lines derived from Spodoptera frugiperda insects by inducing apoptosis. In semi-permissive cell lines, such as Lymantria dispar and Spodoptera littoralis cells, we observed cytopathic effects after infection with AcMNPV but little virus production. Infection of these cells by AcMNPV lacking p35 resulted in apoptosis. However, p35-deficient viruses were still able to replicate normally in Trichoplusia ni, Mamestra brassicae and Panolis flammea cell lines. Disruption of AcMNPV iap1 and iap2 was found not to affect virus replication in any of the cell lines. It was also possible to disrupt both iap1 and iap2 in the same virus without loss of infectivity. A virus without iap1 and p35 demonstrated identical growth characteristics and host range to a virus lacking p35. We conclude that in cells which respond to AcMNPV infection by initiating programmed cell death, the p35 gene product alone is sufficient to inhibit apoptosis. Removal of iap1 or iap2 has no effect on virus replication, even in cell lines which do not undergo apoptosis in response to AcMNPV infection. Our results with two semi-permissive cell lines further indicate that whilst p35 is important in blocking block apoptosis, other factors are involved in restricting AcMNPV replication within these cells.

Sequencing, expression pattern and RFLP mapping of a senescence-enhanced cDNA from Zea mays with high homology to oryzain gamma and aleurain.

Sequence analysis of a 1.4 kb clone from a cDNA library of senescing Zea mays leaves reveals an open reading frame for a 360 amino acid protein. Both the DNA and deduced amino acid sequences are highly homologous to the cysteine proteinases oryzain gamma and aleurain. Northern analysis demonstrates that the corresponding RNA level increases during natural leaf senescence, seedling germination and in chilling of tolerant maize lines, but decreases in a sensitive line. The mRNA level also decreases in regreening leaves, in dark-induced senescence and in nutrient or water stress. Southern and RFLP analysis provide evidence that the gene has two copies, on chromosomes 2 and 7.

Sequence of the nucleocapsid protein gene of Machupo virus: close relationship with another South American pathogenic arenavirus, Junín.

The sequence of the nucleocapsid (N) protein of Machupo virus (causative agent of Bolivian haemorrhagic fever) has been determined, and used to infer a phylogenetic relationship to other arenaviruses. The relationship of the virus to Junín and Tacaribe viruses, together with previous demonstrations of antigenic similarity and cross-protection by heterologous viruses, suggest that vaccines developed against Argentine haemorrhagic fever might also be effective against the Bolivian disease.

Multiple granular cell tumor.

Eleven cases of granular cell tumor were reviewed. In two of the cases multiple sites of involvement were seen. The tumor occurred in the oral cavity in both of these cases and each was initially wrongly diagnosed as squamous cell carcinoma. The most common site was the subcutaneous tissue (nine patients) and the tongue was involved in three cases. In one patient the parotid gland was involved. Eight of the patients were females and three were males; seven were black and four were white. The importance of differentiating between squamous cell carcinoma and granular cell tumor is stressed, as is the need for a simple wide surgical excision.

Radiotherapy and head and neck cancer. Role of lymphocyte respontse and clinical stage.

The mean number of lymphocytes, response to phytohemagglutinin (PHA), and response to concanavalin A (Con A) in whole-blood cultures for 106 patients with head and neck cancer were 83%, 73%, and 64%, respectively, of values for healthy control individuals. During radiotherapy, lymphocyte counts declined to 44% and PHA and Con A responses declined to about one third of control values. Lymphocyte counts slowly increased after treatment to 77% of control values after two years, but responses to mitogens remained at about 40%. Responses to PHA and Con A for 38 patients who lived beyond 18 months were significantly greater before and after treatment than responses for 39 patients who died within 18 months. In general, a poor pretreatment response to PHA and Con A correlated with a poor clinical course, whereas responses near the control level indicated a good clinical course.

Neoglottic reconstruction following total laryngectomy. The galveston experience.

A technique of primary neoglottic reconstruction for surgical restoration of voice following total laryngectomy is described in detail. This technique has been performed on 30 patients at the University of Texas Medical Branmch, and our results are reported. Twenty (67%) of these patients are speaking with their neoglottises after one year. Indications for neoglottic reconstruction are discussed, based on a review of the problems and complications which we have experienced. Relative contraindications to the procedure are extension of tumor beyond the anatomic boundaries of the larynx, patients with poor pulmonary reserve, or those with significant esophageal reflux incompetence. Radiotherapy is nt a contraindication to neoglottic reconstruction. It does predispose the patient to increased morbidity with spontaneous closure of the neoglottis, as well as aspiration, occurring occasionally. Other problems which are discussed include aspiration, postoperative wound infection, and patient compliance with the procedure. Results to date have been very encouraging, meriting further investigation of this one-stage vocal rehabilitation.

Neoglottic reconstruction after total laryngectomy. Staffieri's techniques: a report of 18 cases.

Mario Staffieri and associates developed a technique for reconstruction of a phonatory neoglottis in 1970. Since then Staffiere has performed over 100 of these procedures with approximately a 90% success rate. The technique has been used in 18 cases at The University of Texas Medical Branch in Galveston with certain variations. All patients received a wide field total laryngectomy for T3 or T4 endolaryngeal or pyriform sinus carcinomas. Of these 18 patients, two did not have neoglotic fistulas created. Of the 16 patients who remained in the series, 12 have a good voice. One died of carcinoma of the lung, one had spontaneous closure after postoperative radiotherapy, one aspirated severely and was closed surgically, and the last patient had a postoperative wound infection and closed spontaneously. He developed good esophageal speech.

Neoglottic reconstruction after total laryngectomy: a preliminary report.

This paper is a preliminary report on neoglottic reconstruction of the larynx after total laryngectomy following the techniques described by Staffieri. Also included are general observations on the criteria for selecting candidates for this procedure. At the University of Texas Medical Branch in Galveston, this procedure has been attempted on eight candidates. Reconstruction was accomplished in six, of whom five achieved satisfactory speech, providing an 80% success rate. One of the five did not like the quality of his voice and refused to use it. The sixth produced speech with difficulty and is still undergoing speech therapy. One patient died from recurrence before a second stage could be carried out, and another patient did not have sufficient tissue for neoglottic reconstruction after total laryngectomy. Three patients developed salivary fistulas at the drain site, but all closed spontaneously with the application of pressure. From this data, one may conclude that this technique offers much potential and warrants further study.

Lymphocyte response in patients with head and neck cancer: effect of clinical stage and radiotherapy.

Ffty-three patients with head and neck cancer tested before radiation treatment to determine numbers of blood lymphocytes and immunologic responses to mitogens of lymphocytes in whole-blood cultures had mean values that were 19% to 26% less than values for healthy individuals. Thirty patients whose disease was in stages III or IV had values similar to those in 23 patients whose disease was in stages I or II. Values for 45 patients tested at end of radiotherapy decreased to about 50% of pretreatment values; however, patients with advanced lesions experienced greater decreases (to 24% to 50%) than patients with localized lesions (to 71% to 84%). Patients with advanced lesions usually received radiation to larger areas than patients with localized lesions; therefore, the extent of decline in laboratory values was most likely dependent on volume of tissue treated.

An implanted electronic laryngeal prosthesis.

The authors present a preliminary progress report on their investigations dealing with the development of an implanted electronic laryngeal prosthesis system. Their initial observations indicate success in the design and fabrication of the implantable, retropharyngeal transducer and secondary induction coil elements. The surgical procedure for implantation is described, and the complications encountered during the first thirteen procedures are reported. These complications included five seromas, one postoperative abscess, one partial wound breakdown secondary to animal-inflicited traumn, and two anesthetic deaths at the time of follow-up radiographic procedures. Additional observations are presented regarding the acoustical output of the transducer in air and after implantation. Projections are made concerning the use of this laryngeal prosthesis system in human patients for vocal rehabilitation after total laryngectomy.

Cricoid arch replacement in dogs. Further studies.

Published reports by Delahunty et al and Alonso et al described the feasibility of correcting subglottic defects with cricoid arch transplantation. Using normal dogs, satisfactory results, including airway patency and vocal cord function, were reported. This report describes a second series of dogs in which subglottic stenosis was first induced by an open procedure and was subsequently repaired with an allotransplanted cricoid arch. The resulting subglottic defect in the donor dogs was repaired by autogenous hyoid arch transposition. No immunosuppressive measures or stents were used in either group. The animals were followed for periods up to one year prior to histologic study. Satisfactory results were obtained in both groups.