Intracranial meningioma.

Eighty-three patients with intracranial meningioma were retrospectively analyzed with regard to age, sex, anatomic location, mode of presentation and surgical outcome. The ages of the patients ranged from 11 to 77 years. Fifty-five (66%) were females and 28 (34%) were males. The peak incidence occurred between 40 and 49 years. The locations of the meningioma were as follows: 42.2% in the convexity, 15.7% in the parasagittal, 12.1% in the tuberculum sellae, 8.4% in the sphenoid ridge, and three cases with multiple lesions. Forty-two percent of our series were found to have hyperostosis of the skull bone. There were 7 cases with cyst formations found through computed tomography (CT). Histological classification showed 48.3% to be of meningothelimatous type, while 18.4% were of psammomatous type. One of the multiple meningiomas showed two different histological types. The degree of perifocal brain edema at CT scan was found to be related to the symptoms, the size of the tumor and seizure attack. Fifty-three out of 54 patients with episodes of seizures were found to have perifocal brain edema, whereas the histological features were less significant. Seventy-one tumors were treated by total resection and 16 tumors by subtotal resection. Follow-up study from 1 to 7 years showed the rate of recurrence in the total resection group to be 11.3%; in the subtotal resection group without radiation 42.9%, and in the subtotal resection group with radiation 66.7%. The over-all recurrence rate was 19.5% in our series.


[Preparation and characterization of antibodies against Bungarus multicinctus venom by liposomes].

Bungarus multicinctus venom was incorporated into sphingomyelin-cholesterol liposomes which were stabilized with osmium tetroxide. The lethal toxicity of B. multicinctus venom in osmicated liposomes greatly decreased to 1.03% that of crude venom. Rabbits were divided into four groups for immunization. Group A was immunized with crude venom, group B and group C with osmicated liposomes, and group D with osmicated liposomes followed by the crude venom. Immunization was performed in the presence of Freund's adjuvant except for group B. The antibody levels during the course of immunization were measured by ELISA and the contents of precipitating antibody were determined by quantitative precipitin reactions, while that of non-precipitating antibody was determined by affinity chromatography. Although the immune response was not increased by incorporating lipopolysaccharide immunostimulant, the specific neutralizing capacity of purified antibody from the pooled antisera of group D was more potent than that of the others. The almost non-toxic osmicated liposomes of B. multicinctus venom may be useful immunogens for the production of antiserum for treatment of snake bites.


Central odontogenic fibroma of the mandible--a case report.

A 32-year-old male was referred to the Department of Oral and Maxillofacial Surgery, Kaohsiung Medical College Hospital, with the chief complaint of swelling in the region of the right mandibular angle. The histopathological examination confirmed the diagnosis of central odontogenic fibroma. A surgical enucleation with a surrounding bone trimming and an iliac bone graft was performed under general anesthesia. A three years follow-up showed good bone regeneration and no evidence of local recurrence.


Splenic rupture as an infectious mononucleosis complication.

Splenic rupture is a rare yet serious complication associated with an infectious mononucleosis, especially in those patients with atypical clinical manifestations or those whose presentations are nonspecific or even completely asymptomatic. Since the death in these occasions is mostly attributed to acute massive hemorrhages, an early diagnosis and treatment is of paramount importance. This report illustrates that in infectious mononucleosis, one should be aware of the possibility of an unusual clinical presentation and the enlarged spleen may rupture spontaneously or by a causal traumatic force. White blood cell counts and their differentials at this catastrophic event may not be helpful in diagnosing infectious mononucleosis.


A trial of adenosine for the termination of supraventricular tachycardia in infancy: a case report.

A 40-day-old male infant was admitted due to cough, anorexia and pale face. Rapid heart beat was found accidentally by auscultation. Electrocardiograms revealed supraventricular tachycardia (SVT) with a heart rate up to 250 beats per minute, and an absence of P waves. Intravenous bolus injection of 1 mg adenosine terminated the tachycardia, followed by transient complete atrioventricular block, then latent Wolff-Parkinson-White (WPW) syndrome with retrograde P waves. Adenosine may be a new trial for the termination of SVT, and also is a safe drug even in the presence of WPW syndrome.


Pathology of common pulmonary fungal infections.

The incidence of fungal pneumonias has increased dramatically since the 1960s, particularly in immunocompromised patients. Fungal infections may be divided into endemic and opportunistic varieties. In general, the truly pathogenic (endemic) fungi infect healthy individuals, and opportunistic fungi usually infect only immunocompromised hosts. Almost all common fungal infections are acquired by inhalation of contaminated soil, resulting in pulmonary infections. Once in the lungs, the fungi elicit tissue responses ranging from acute exudative reactions to granulomatous reactions. The pulmonary lesions may resolve, progress to a prolonged chronic course, or disseminate to other organs, resulting in systemic infections. The diagnosis of fungal infection depends on the demonstration of the organisms by culture or histology; serologic tests may confirm the diagnosis. Fungi in tissues can be identified by hematoxylin and eosin stains, but special stains such as Gomori's methenamine silver and periodic acid-Schiff reagent are often required for diagnosis.


Clinical manifestations of pulmonary fungal infections.

Coccidioidomycosis, histoplasmosis, cryptococcosis, and blastomycosis are the most common deep pulmonary fungal infections encountered by the clinician. Each has a particular environmental habitat. As world travel increases, exposure to these infections becomes increasingly more common. The article reviews the microbiology, natural history, and clinical and laboratory findings of these diseases. Treatment options for these infections also are discussed.


Pulmonary blastomycosis.

Pulmonary blastomycosis has a number of chest radiographic manifestations that may closely resemble those of tuberculosis, histoplasmosis, and other fungal diseases. Radiographic presentations of disease include airspace consolidation, nodular opacities, air bronchograms, masslike lesions, and military disease. Because the geographic distribution of blastomycosis overlaps that of histoplasmosis, distinguishing one from the other on the basis of the radiographic features may be difficult. In blastomycosis, the paucity of calcifications, lymphadenopathy, and cavitation is striking. The article reviews the clinical and radiologic features of blastomycosis and provides illustrative cases to enhance understanding of this disease.


Pulmonary coccidioidomycosis.

Coccidioidomycosis is a fungal disease endemic in the southwestern desert area of the United States. The infection is acquired by inhalation of arthrospores, and 60% of the infections are asymptomatic. Chest radiographic abnormalities are common and may even be seen in asymptomatic cases. In patients with acute infection, segmental or lobar consolidation and nodular or patchy pulmonary opacities are frequent. Hilar and mediastinal adenopathy may be present in 20% of cases, usually with parenchymal findings. A small pleural effusion may occur in 20% of cases. Approximately 5% of patients with primary disease are left with chronic, residual lesions of the lung. These consist of nodules, cavities, pneumonia, adenopathy, pleural effusion, fibrosis, bronchiectasis, and calcification. Rarely, in about 0.5% of cases, the infection may disseminate to any organ. The chest radiograph demonstrates a miliary or reticulonodular pattern and mediastinal adenopathy. Overall the disease is benign in nature; but patients with severe, progressive pulmonary or disseminated disease often require medical and occasionally surgical management.


Thoracic histoplasmosis.

Histoplasmosis is a fungal disease that is seen throughout the world. It is the most common systemic fungal infection in North America, and it is endemic in the Mississippi, Ohio, and St Lawrence River valleys. Its radiographic and clinical spectrum ranges from a totally self-limited disease with minimal or no radiographic findings to a rapidly progressive, disseminated, and sometimes fatal disease. The article discusses the various aspects of thoracic histoplasmosis with emphasis on the radiographic findings.


Pulmonary cryptococcosis.

Cryptococcus neoformans is a ubiquitous soil fungus that rarely causes pneumonia in normal hosts but is a common cause of opportunistic infection. Pulmonary disease is initiated by inhalation of the organism, and a spectrum of radiographic manifestations can be seen. The most common finding is a poorly marginated nodule or mass. Lobar or segmental parenchymal opacities and, less commonly, a diffuse scattered nodular or reticulonodular pattern have also been observed. Associated adenopathy, pleural effusions, and cavitation are uncommon; when present, these are more common in immunocompromised patients. Establishing the diagnosis can be difficult, but pulmonary cryptococcosis should be considered in the differential diagnosis of patients in the proper clinical setting and with compatible radiographic findings.


The spectrum of pulmonary aspergillosis.

Aspergillus species can produce a wide range of pulmonary disorders. Classically, pulmonary aspergillosis has been categorized into invasive, saprophytic, and allergic forms, all of which differ in their manifestations and therapy. More recently, however, other types of infection by this fungus have been recognized that do not fit into these traditional categories; an example is semi-invasive (chronic necrotizing) aspergillosis. In fact, these forms have features that are intermediate between those of the invasive and saprophytic types. The various types of aspergillosis can be regarded as constituting a continuous spectrum, ranging from invasive disease in the severely immunosuppressed patient to hypersensitivity reactions such as allergic bronchopulmonary aspergillosis (and bronchocentric granulomatosis) in the hyperreactive patient. Between these extremes are chronic necrotizing disease seen in midly immunocompromised hosts, and the noninvasive aspergilloma, which is due to saprophytic growth within a previously diseased area of lung in an otherwise normal host. Other intermediate forms may be encountered, their behavior being determined by the host immune status in combination with the underlying lung morphology. The radiographic and clinical features of these various forms of pulmonary aspergillosis are reviewed, including the more recently reported forms of infection such as Aspergillus tracheobronchitis and aspergillosis associated with acquired immunodeficiency syndrome and cystic fibrosis. The proposed concept of a disease spectrum is emphasized.


Actinomycosis and nocardiosis of the lung.

Actinomyces and Nocardia species are frequently overlooked pulmonary pathogens until their presence is histologically proved. These infections often are not considered in the differential diagnosis of lung disease because of the spectrum of their presentation, the similarity of their appearance to other granulomatous or neoplastic diseases, and coexistence of these infections with other pulmonary conditions. Pulmonary actinomycosis is characterized by pulmonary consolidation, frequently with cavitation and spread to contiguous tissues without regard for normal anatomic barriers. The appearance often is confused with that of bronchogenic carcinoma or other granulomatous infections, especially tuberculosis. Pulmonary nocardiosis most frequently develops in immunocompromised patients, and the incidence of this infection is increasing. The radiographic manifestations of nocardiosis are pleomorphic, but early recognition is essential to initiate appropriate therapy.


Pulmonary zygomycosis: a radiographic and clinical spectrum.

Eight documented cases of pulmonary zygomycosis were analyzed retrospectively with regard to radiographic and clinical features. Predisposing factors were diabetes mellitus in six cases, lymphoblastic lymphoma in one case, and surgery to correct a tracheoesophageal fistula in one case. Two of the patients with diabetes had also undergone renal transplantation for diabetic nephropathy and were immunosuppressed. The more usual radiographic findings of pulmonary zygomycosis represent a spectrum that comprises a normal chest radiograph, a lung abscess, subacute or chronic pneumonia that often evolves into a lung abscess, and rapidly progressive fatal pneumonia. Awareness of the various presentations of pulmonary zygomycosis is important because early diagnosis and appropriate therapy clearly have been shown to improve the survival rate of these patients. Zygomycosis should be included in the differential diagnosis when patients with diabetes mellitus, patients with leukemia or lymphoma, or immunocompromised patients present with or develop perplexing pulmonary abnormalities.


Fungal infections of the chest in infants and children.

Although fungal infections of the thorax are often asymptomatic in children, fungi are capable of producing significant pulmonary and mediastinal disease in this population. Young infants and immunocompromised children are at increased risk for fungal infections and often develop disseminated disease. Pulmonary fungal infections present with a wide variety of findings, many of which are nonspecific. The article reviews the clinical and imaging characteristics of the more important fungal diseases that affect the thorax of infants and children.


The use of diarrhoeal management counselling cards for community health volunteer training in Indonesia: the HealthCom Project.

The Indonesian Ministry of Health relies on a network of over a million kader (community health volunteers) to bring primary health care to the village level. In West Java, the Department of Health's Control of Diarrhoeal Disease (CDD) Program recently carried out an extensive research and development effort to produce effective job aids for the kader in CDD and a training programme to teach their use. A set of counselling cards was produced to provide kader with a tool to diagnose and treat diarrhoea and teach the proper use of ORS. Researchers conducted a controlled evaluation in which they measured the cards' effectiveness through observations of kader performance and interviews with mothers they had counselled. In the intervention group, 15 kader underwent two days training in the use of the cards when diagnosing and advising treatment for cases of diarrhoea in their villages. The 16 control kader received comparable CDD training without the cards. Each group provided lists of local mothers they pledged to counsel during the coming weeks. Follow-up interviews were held with these mothers to test their level of knowledge on CDD and to observe their ability to mix ORS properly. Significant performance differences between the intervention kader and mothers, and the control kader and mothers, were demonstrated. The intervention kader were consistently more accurate in their diagnoses and recommendations for treatment with a mean of 83% accuracy vs 68% for the control kader. Mothers counselled by the intervention kader also prepared ORS significantly better than the mothers counselled by the control kader, with 97 vs 74% accuracy.


Influence of socioeconomic factors on the treatment and prevention of malaria in pregnant and non-pregnant adolescent girls in Nigeria.

The influence of socioeconomic factors on the treatment and prevention of malaria was investigated in 45 pregnant and a control group of 47 non-pregnant adolescent girls in the rural community of Imesi-Ile, Nigeria. The study consisted of focus group discussions and a house-to-house survey. During the survey, clinical and anthropometric measurements were taken of the girls and they were assisted in completing a prepared questionnaire which sought information on their methods of treatment and prevention of malaria. The results showed a higher incidence of malaria parasitaemia, anaemia and fever episodes in the group of pregnant adolescent girls. Both groups of girls use identical methods for the prevention of malaria but only a few pregnant girls as compared to non-pregnant girls receive modern hospital treatment for malaria. In particular, pregnant unmarried girls were less likely to receive antenatal care, to use the local health centres for the treatment of malaria and to adopt appropriate measures for the prevention of malaria. This trend was not due to aversion to hospital treatment since most people in the community prefer modern treatment of malaria to traditional or religious methods of treatment. The low utilization of hospital treatment by the pregnant girls was found to be due to perceived high cost of treatment at the health centres and to lack of privacy. We conclude that a malaria treatment service that utilizes modern methods and is both cheap and confidential will be preferred by pregnant adolescent girls in Imesi-Ile.


Enterotoxigenic drug resistant plasmids in animal isolates of Escherichia coli and their zoonotic importance.

A study was undertaken to determine how widely drug resistant enterotoxigenic plasmids are distributed among the animal isolates of Escherichia coli, and their potential for exchange. Thirty-one strains of E. coli isolated from metritis, septicaemia and diarrhoea of animals were tested for the production of enterotoxins. Thirteen strains were enterotoxin producers. Five produced heat-stable enterotoxins (ST), four heat-labile (LT) and four strains produced both (LT/ST) types of enterotoxins. Most of the enterotoxin producing E. coli strains were isolated from diarrhoeal sources, followed by septicaemia and metritis. Of the 13 enterotoxigenic E. coli, nine were resistant to various antibiotics which transferred their drug resistance partially or completely into an E. coli K-12 recipient. Only one strain of serogroup 032, isolated from equine metritis, transferred ampicillin, oxytetracycline and doxycycline resistance and heat-labile enterotoxin biosynthesis determinants en bloc. Plasmid DNA analysis of the exconjugants showed the presence of a 41.8 MDa conjugative plasmid. The presence of such autotransferable enterotoxin biosynthesis replicons in their unusual ecological niches such as metritis and septicaemia suggests the ubiquitous nature of enterotoxin genes which perhaps were selected and spread due to the presence of genes for drug resistance. The potential of cross-infection of human beings from animals and vice versa via such plasmids is discussed.


Experimental infection of dogs with a Zimbabwean strain of Rickettsia conorii.

Seroconversion was demonstrated in dogs artificially infected with a Zimbabwean strain of Rickettsia conorii. No haematological or biochemical abnormalities were found and the only clinical signs observed were pain, erythema and oedema at the inoculation site and regional lymphadenopathy. Intermittent rickettsaemia was detected using the centrifugation shell vial technique up to 10 days post inoculation.


The laboratory diagnosis of rickettsial diseases in Hong Kong.

Indirect immunoperoxidase (IP) tests against antigens of Rickettsia typhi, R. sibirica and R. tsutsugamushi were carried out on serum samples from 10 patients known to have high titres against one or more Proteus OX antigens in the Weil-Felix (WF) test. The IP test confirmed rickettsial infection in nine of the 10 patients, giving unequivocal indications of the grouping of the infecting Rickettsia species and, in one instance, showing a diagnostic IgM titre in a specimen taken on day 3 of the patient's illness. IP tests confirmed four cases of spotted fever group rickettsial infection, three cases of urban or murine typhus and two of scrub typhus.


Visceral leishmaniasis with cysticercosis.

A chest wall nodule in a boy with relapsed proven kala-azar was found to contain a cysticercus. In the fibrous wall with lymphohistiocytic aggregates were mononuclear phagocytes containing amastigotes of L. donovani.


Laboratory studies on Yersinia pestis during the 1991 outbreak of plague in Lushoto, Tanzania.

Thirty-one specimens from patients involved in an outbreak of plague were cultured. Suspicious isolates were presumptively identified by colonial characteristics, simple strains and by API 20E, and confirmed by inoculation into white mice. Antimicrobial susceptibility testing was also done. The isolation rate of Y. pestis was 22.6%. All isolates were uniformly sensitive to tetracycline, streptomycin, sulphadimidine and chloramphenicol; moderately sensitive to erythromycin, and resistant to trimethoprim. Y. pestis was confirmed as a cause of the epidemic and sensitivity of Y. pestis to the four antimicrobial agents used was demonstrated. It is recommended that laboratories in zonal hospitals serving areas with plague foci should be provided with facilities for isolation and preliminary identification of Y. pestis in order to speed up diagnosis of plague outbreaks. Confirmation of the identity, biotyping and antibiotic susceptibility testing should be undertaken in a well established national reference laboratory. This appears to be the first publication on bacteriological investigations of human plague in Tanzania.


Enteropathogenic Escherichia coli as a cause of diarrhoea among children in Singapore.

Enteropathogenic Escherichia coli (EPEC) was isolated from 2.7% of 2983 children under 3 years of age with diarrhoea in Singapore. Of the nine serotypes identified, the most common were 0126:K71(B16), 086:K61(B7) and 0127:K63(B8). Infants were at the greatest risk of contracting gastroenteritis due to EPEC, and female children were slightly more susceptible than males. Antimicrobial susceptibility tests showed that the EPEC strains were generally resistant to ampicillin, streptomycin, tetracycline and triple sulpha, but highly sensitive to ceftriaxone and gentamicin.


Caesarean sections in developing and developed countries.

A clinical study of 1086 cases of caesareans done in the period 1987-1991 in a rural institute is presented with a review of the latest data from India and elsewhere. Of the women, 86.19% were between 20 and 30 years; 43.83% were primigravidas. The most common indications were obstructed labour and malpresentations. 17.76% of the emergency and 14.64% of registered obstetric admissions resulted in caesarean delivery. The status of caesarean births is very different in developed and developing countries though both face the problem of its very high incidence.


Human infection by Phagicola sp. (Trematoda, Heterophyidae) in the municipality of Registro, São Paulo State, Brazil.

In 1988, nine cases of human parasitism by Phagicola sp. were diagnosed in the municipality of Registro (São Paulo State, Brazil) by stool examinations, in patients who ate raw mullet (Mugil sp.). Six (66%) of the nine patients suffered from flatulence and four (44%) had diarrhoeal episodes; six (66%) showed slight eosinophilia. On the same occasion, 61 dogs and 11 cats from Registro were also submitted to stool examination. Only one dog (1.6%) showed Phagicola eggs in the stool. All patients were treated with a single dose of praziquantel (50 mg kg-1 body weight) and control stool tests performed on the 15th, 30th and 60th days post-treatment showed no trematode eggs.


Intestinal obstruction due to Taenia saginata infection: a case report.

Surgical complications of Taenia saginata infection, the bovine tapeworm which man acquires by eating undercooked beef, are mentioned in standard texts; however, none of these seem to give any specific reference. Reported here is one case of acute mechanical intestinal obstruction due to a bolus impaction of Taenia saginata at the level of the ileocaecal valve. The rarity of this clinical presentation as well as the probable mechanism of obstruction are discussed.


Chronic diarrhoea due to strongyloidiasis in a Nigerian with chronic renal failure: a case report.

A case of chronic diarrhoea due to infection with Strongyloides stercoralis in a Nigerian patient with chronic renal failure is presented. Due to the potential for fatal outcome in this infection, strongyloidiasis should be kept in mind as a cause of chronic diarrhoea in chronic renal failure patients in endemic areas.


Typhoid fever and nephrotic syndrome--an unusual association.

We report a case of nephrotic syndrome seen in a 9-year-old boy having a significant temporal relationship with culture proven multidrug resistant Salmonella typhi infection. Such an association is quite unusual and probably has not been reported before.


Management of substernal goitre.

Goitres of the thyroid gland whose major component resides substernally would appear to have a different presentation and management protocol than those goitres that reside mainly in the neck. These goitres, as opposed to their supraclavicular counterparts, usually present with symptoms referrable to compression of the trachea or esophagus. Even in those patients who are asymptomatic, a precise history may elicit pertinent findings. Furthermore, these goitres do not respond to suppression and require surgical removal. The trans-cervical approach is the most desirable, but the surgeon must be willing to enter the chest on that rare occasion. We reviewed the charts of 938 patients undergoing thyroid surgery who were registered in the Head and Neck Tumour Registry of the University of Toronto. Approximately 2.4% of patients had substernal goitres. Their history, pathology and ultimate surgical management will be discussed.


Necrotizing cervical fasciitis of unknown origin.

Necrotizing fasciitis is an acute soft-tissue infection rarely seen in the head and neck area. The case of a 29-year-old female with necrotizing cervical fasciitis of unknown origin is presented. These infections usually result from dental infections; this patient, however, denied any associated dental problems. The patient presented with an erythematous swelling over the anterior neck associated with a choking sensation and an elevated WBC suggestive of acute thyroiditis. After three days of hospitalization the skin over the anterior neck area became necrotic. Surgical debridement of the area was undertaken with significant improvement. Once wound healing had commenced a pedicled flap was used to reconstruct the large defect. Flap selection for closure of the defect is discussed. It is apparent that early recognition and surgical debridement of necrotizing fasciitis is vital to ensure a rapid recovery.


Congenital fistula of the apex of the pyriform sinus: an overlooked phenomenon of debatable origin.

Fistula of the pyriform sinus apex is an often overlooked entity which generally manifests itself as acute suppurative thyroiditis or recurrent deep neck abscesses in children or young adults. Two cases are reported. Arguments in favor of a fourth pharyngeal pouch origin are stressed and the surgical management is described.


Hemangioma of the masseter muscle.

Intramuscular hemangiomas are rare benign tumors of vascular origin. The masseter is the muscle most commonly involved in the head and neck. A case of intramuscular masseter hemangioma is presented, the literature reviewed, and appropriate diagnostic modalities discussed.


Malignant melanoma of the upper respiratory tract and the oral cavity.

Twenty-six patients with mucosal malignant melanoma of the upper respiratory tract and of the oral cavity were seen at the oncologic departments of eastern Denmark from 1955 to 1989. There were 17 males and nine females with an average age of 65 years. Primary symptoms lasted from one to 24 months and depended on localization of tumor. Five patients had lymph node metastases at the time of diagnosis; one also had distant metastases. Ten patients had surgery as primary treatment, 10 had combined surgery and radiotherapy and six had radiotherapy. Complete remission after primary treatment was seen in 22 cases (85%) and lasted from three to 94 months. Seventeen patients had recurrence, six of these had recurrence twice or three times. The five-year crude survival was 35% and only one patient (4%) lived more than 10 years. Recurrence-free survival among the 22 patients with initially complete response was 14%.


Extracranial head and neck schwannomas.

Extracranial head and neck schwannomas are usually benign and rarely malignant tumors of peripheral nerve sheath origin. The clinical presentation of these tumors is reviewed in our series of 21 patients, emphasizing the diagnosis with dynamic infused CT scans. Management is suggested and outcome analysis is provided.


The importance of nasal resistance in obstructive sleep apnea syndrome.

The importance of nasal airflow resistance in the pathogenesis of obstructive sleep apnea syndrome (OSAS) remains contentious. We performed formal nocturnal polysomnography (PSG) on OSAS patients under conditions of baseline and reduced nasal resistance to answer two main questions. First, to what degree does baseline nasal airflow resistance influence upper airway collapse in OSAS patients? Second, in what proportion of the OSAS population is baseline nasal resistance contributing to the pathogenesis of upper airway collapse? Our study group consisted of 10 patients with a wide range of OSAS severity. Six of these patients had symptoms and clinical evidence of chronic nasal obstruction which, in some, was associated with markedly elevated nasal resistance. A placebo (normal saline) was instilled in the nose of each patient on the night of baseline data collection. On the treatment night of the study, nasal resistance was reduced by application of topical vasoconstrictor and insertion of vestibular stents designed to dilate the area of the nasal valve. Posterior rhinomanometry was used to measure resistance to nasal airflow immediately before and after each PSG study. Although treatment was associated with a subjective improvement in sleep quality and mean drop in nasal resistance of 73% (P less than 0.001), there was no significant improvement in sleep architecture, nocturnal oxygenation, or the amount of apnea experienced by patients. The most significant improvement was a reduced number of arousals/hour from 52.4 +/- 12.4 on placebo to 43.7 +/- 10.2 on treatment (P less than 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)


Oncocytoma presenting as a choanal polyp: a case report.

Oncocytomas account for less than 1% of all salivary gland neoplasms. Histochemical methods and electron microscopy showing the large amount of characteristic mitochondria have made the definition of the tumor more precise. A solid oncocytoma originating in the nose and presenting as a choanal polyp is described. Pre- and postoperative CT scans are shown as light and electron microscopy photomicrographs. The tumor had no invasive or other malignant characteristics and was therefore classified as a benign oncocytoma.


Stromal calcification in choanal polyp.

A 50-year-old man, presenting with headache, was suspected of having a malignant nasopharyngeal tumor on the basis of his CT results. A CT scan revealed diffuse calcification in a large nasopharyngeal polyp. Xeroradiography of the specimen demonstrated the calcifications to extend centrally along the stroma. The histology and the radiologic features of this choanal polyp, resulting from diffuse central calcification of the stroma, are a unique feature that might mimic malignancy.


Is head-shaking nystagmus a sign of vestibular dysfunction?

It has been proposed that head-shaking nystagmus is a reliable test or indicator of vestibular dysfunction. Using a series of 340 patients and 20 controls, this paper compares the vestibular test data to head-shake test data to answer some of the questions about this poorly understood response. Head-shaking nystagmus appears to reflect the underlying spontaneous nystagmus and its direction has no relationship to the side of the vestibular asymmetry.


Electrocochleographic recordings in chronic and healed perilymphatic fistula.

This study examined electrocochleographic recordings in 15 guinea pigs with perilymphatic fistulas. A chronic round window fistula was induced in each animal by insertion of a sigmoid stainless steel needle with the lumen intact. In the contralateral control ear, a similar needle was inserted with the lumen crushed. In this way the model compared acute (control group) versus chronic (experimental group) perilymphatic fisulae. Electrocochleographic recordings were obtained before, immediately after needle insertion, in a subset at two to three weeks after needle insertion, and again at 17-22 weeks when the fistulas had healed with the needles still in place. Minimal threshold changes were noted from the pre- to the acute post-condition. More marked elevation of threshold was noted for the 17-22 weeks condition. Threshold elevation was greater in the experimental ears but was present in the control ears. The SP/AP amplitude ratio was generally stable for the pre- to post-conditions in both ears. For the 17-22 week epoch the SP/AP amplitude ratio was still fairly stable for the click stimulus but the ratio diminished for the toneburst stimuli. For the subset analyzed at 7-21 days the SP/AP amplitude ratio tended to increase for both groups for all stimuli although AP thresholds were normal.


Gore-Tex implant as tissue filler in cheek-lip groove rejuvenation.

The cheek-lip grooves, often referred to as nasolabial folds, are one of the facial characteristics most commonly complained about by patients in all age groups. A variety of methods for correction have been proposed, using implants or autografts. Some of the methods have relied on diminishing the crest lateral to the groove thus camouflaging the depth of the cheek-lip fold. These procedures have proven to be of limited effect, either because of the amount of correction obtained or because they are short-lasting. The Gore-Tex implant proved its safety and biocompatibility over the past decade as a vascular graft. The characteristics of this implant material are described and compared to other commonly used synthetic implants. A surgical technique of applying the Gore-Tex soft tissue patch in facial aesthetic surgery, particularly in cheek-lip rejuvenation, is presented. This technique has been applied in 17 consecutive patients for the correction of prominent cheek-lip grooves with a follow-up period of eight months. Results showed satisfactory improvement without significant complications.


Otitis media and CNS complications.

Intracranial complications from otitis media can be quite devastating to the patient if an early diagnosis is not made. Patients may develop meningitis, venous sinus thrombosis or cranial nerve palsies, as well as intracranial abscess. The presenting features in such cases may be subtle and include headache, nausea, vomiting, personality changes and signs of increased intracranial pressure as well as focal neurological deficits. A case of intracranial brain abscess is presented in a patient with a history of chronic otitis media with cholesteatoma. Delay in the diagnosis of intracranial complications of otitis media can lead to improper treatment with increased morbidity and mortality. The etiology and treatment of complications affecting the CNS is discussed.


Longitudinal evaluation of uterine myoma growth during pregnancy. A sonographic study.

Thirty-six pregnant women with a single uterine myoma were examined by ultrasonography at 2 to 4 week intervals. The initial diagnosis was made in 12 patients before pregnancy and in the other 24 patients between 9 and 12 weeks of gestation. Thirty-four women had a scan 4 weeks after delivery. A reduction in size was observed in puerperium, which may indicate a return to its initial volume. Myoma growth was analyzed in different periods of gestation. An increase in volume during pregnancy was observed in 31.6% of cases. A statistically significant change in volume was noted between the first and the third trimesters (P < 0.001). The greatest increase in volume of myomas occurred before the 10th week of gestation. The relationship between myoma volume and myoma growth in the different gestational periods considered was not statistically significant. On the other hand, when myoma volume was related to complications during pregnancy or at delivery, a statistically significant difference was observed. Myomas with volumes greater than 200 cm3 show a higher rate of complications than those with volumes equal to or less than 100 cm3.


Effect of verapamil on portal blood flow in patients with liver cirrhosis.

The effect of acute (80 mg orally) and prolonged (240 mg orally daily for 2 weeks) verapamil administration on portal blood flow was studied in 12 patients with histologically proved alcoholic liver cirrhosis. Portal hemodynamics were examined by the ultrasonic duplex Doppler system. Thirty minutes after acute verapamil administration, the following parameters remained unchanged: (1) cross-sectional area of the portal vein, from 1.52 +/- 0.41 to 1.51 +/- 0.43 cm2; (2) portal blood velocity, from 13.2 +/- 1.6 to 13.4 +/- 1.6 cm/s; (3) estimated volume of portal blood flow, from 931 +/- 96 to 954 +/- 103 mL/min; and (4) congestion index of the portal vein, from 15.1 +/- 8.3 to 15.6 +/- 8.8 cm, respectively (P = > 0.05). In addition, no significant changes in portal blood hemodynamics were noted after prolonged verapamil administration (P > 0.05). These results demonstrated that verapamil did not alter portal blood flow in patients with alcoholic liver cirrhosis.


Various sonographic patterns of smooth muscle tumors of the gastrointestinal tract: a comparison with computed tomography.

To evaluate the sonographic patterns of smooth muscle tumors of the gastrointestinal tract, we analyzed 25 patients with histologically confirmed smooth muscle tumors. Sonography revealed no abdominal mass in seven patients (sonogram-negative), and abdominal masses in 18 patients (sonogram-positive). The mean size of tumors in the sonogram-negative group (4.5 +/- 1.5 cm) was smaller than that in the sonogram-positive group (11.4 +/- 3.5 cm). We classified the various sonograms into three patterns. Comparing the sonograms with the computed tomographic pictures of each pattern, we theorized that the different patterns on sonograms may be caused by tumor necroses of different sizes with or without gas in the necrotic cavity. For the necrotic tumors, the size of the necrotic area did not correspond to the size of the tumor. However, the tumors with necroses were significantly larger than those without necroses. A central necrosis was found in cases exhibiting both leiomyosarcoma and leiomyoma. On comparing the sonogram-positive and sonogram-negative groups, we found that the size and location of a tumor may affect the detection rate of that tumor by sonography.


The "lying down" adrenal sign: a sonographic indicator of renal agenesis or ectopia in fetuses and neonates.

An inability to image the kidneys, severe oligohydramnios, and an empty (nonvisualized) urinary bladder are the most common sonographic findings in fetuses with renal agenesis. The same features, except for the oligohydramnios, are seen in neonates with renal agenesis. Failure to visualize a kidney in the usual flank location with or without demonstration of the kidney in an ectopic location may also be a feature in fetuses or neonates with renal ectopia. The adrenal gland has an unusual but distinctive appearance on longitudinal sonograms in these patients. Sonograms of 23 fetuses and six neonates referred for presumed bilateral or unilateral renal agenesis or ectopia were reviewed retrospectively for the presence of a flattened ("lying down") adrenal gland. At the time of the examination, the adrenal gland was not actively sought as a part of the fetal survey or postnatal examination but was found retrospectively in 48% of these subjects. Although this finding has been described previously, the emphasis was on this observation as a potentially confusing sonographic feature. This manuscript emphasizes the characteristic appearance of the adrenal gland which instead serves as a simple means of confirming that the kidney did not develop in the flank. Detection of a flattened ("lying down") adrenal gland is an observation that should be actively sought in all fetuses and neonates with a presumed diagnosis of renal agenesis or ectopia.


Doppler flow velocity waveforms in fetal surveillance of twins: a prospective longitudinal study.

In 37 consecutive twin pregnancies, monthly Doppler sonographic measurements were made of blood flow velocity waveforms of the internal carotid and umbilical artery of each fetus. A total of 197 Doppler studies were performed. Of the 74 infants, 23 were small for gestational age (SGA). Thirty-five of the SGA Doppler studies were abnormal, giving an overall sensitivity for predicting SGA fetus of 58% and a positive predictive value of 71%. These data are not as sensitive and specific as our earlier data; however, Doppler criteria preceded sonographic diagnosis of SGA by a mean interval of 3.7 weeks and demonstrated better sensitivity and specificity. A combination of these parameters improves sensitivity to 84%. We conclude that Doppler velocimetry complements real-time ultrasonography for the early diagnosis of abnormal growth in twin pregnancies.


Color Doppler sonography in the evaluation of the adult acute scrotum.

Color Doppler sonography (CDS) was used to evaluate 35 adult males with acute scrotal discomfort. Correlative nuclear scintigraphy was performed in 15 patients. Surgical correlation was available in 10 patients with clinical follow-up in the remaining 25. The complete absence of intratesticular color flow was used as our criterion for testicular ischemia. This was found to be 100% sensitive and 100% specific in 8 patients with surgically confirmed testicular ischemia. Spontaneous detorsion was noted in one patient with hyperemia demonstrated by color imaging. Increased color flow was found in 20 patients with the clinical impression of scrotal inflammation. Nuclear scintigraphy and color Doppler imaging had 100% agreement in 15 patients. Color Doppler sonography is a useful and highly accurate diagnostic method in the evaluation of patients with the acute scrotal syndrome. Color flow imaging is comparable to nuclear scintigraphy in the diagnosis of testicular ischemia.


Cap-independent translation by the 5' untranslated region of Theiler's murine encephalomyelitis virus.

The RNA genome of Theiler's murine encephalomyelitis viruses, a picornavirus belonging to the genus Cardiovirus, is translated in infected cells to a polyprotein. Unlike cellular messages, the 5' end of the RNA is not capped, and the untranslated region (UTR) is quite long (1,064 nucleotides in size). In poliovirus and encephalomyocarditis virus, the 5'UTR is thought to mediate cap-independent translation. We report here experiments to determine the role of the Theiler's murine encephalomyelitis virus 5'UTR in translation. Recombinant DNAs were constructed that were transcribed into bicistronic mRNAs encoding 5' chloramphenicol acetyltransferase intercistronic sequences linked to luciferase and a poly(A) 3' tail. The sequences of the 5'UTR, either complete or with sequential 5' deletions, were inserted into the intercistronic region. Bicistronic RNA transcripts were translated in a rabbit reticulocyte lysate or used to transfect BHK-21 cells, and chloramphenicol acetyltransferase and luciferase synthesis was quantitated. The results strongly suggest that the Theiler's virus 5'UTR promotes cap-independent translation and that the 5' boundary of the relevant signals resides 3' to nucleotide 500. Monocistronic mRNAs were synthesized by using an expression vector in which the 5'UTR containing deletions at the 3' terminus was inserted 5' to the coding sequences for luciferase. Analysis of luciferase translation in a rabbit reticulocyte lysate suggests that the 3' end of the translation initiation signal lies between nucleotides 1043 and 1053.


Antioxidants selectively suppress activation of NF-kappa B by human T-cell leukemia virus type I Tax protein.

Oxygen radical scavengers, such as dithiocarbamates and cysteine derivatives, inhibit activation of the ubiquitous transcription factor nuclear factor kappa B (NF-kappa B) after treatment of cells with tumor necrosis factor, phorbol ester, and interleukin-1. An involvement of oxygen radicals was more directly evident from the induction of NF-kappa B by low concentrations of H2O2 and the demonstration that cells stimulated with various NF-kappa B inducers release H2O2 and superoxide. In this study, we used the antioxidant pyrrolidine dithiocarbamate (PDTC) to investigate whether the activation of NF-kappa B by the viral transactivator Tax from human T-cell leukemia virus type I also depends on the production of reactive oxygen intermediates. The Tax-induced activation of the DNA-binding activity of NF-kappa B in Jurkat T cells was potently suppressed by micromolar concentrations of PDTC. Within the same concentration range, PDTC and two other dithiocarbamates also strongly interfered with transactivation of the long terminal repeat (LTR) of human immunodeficiency virus type 1 by Tax but had no effect on transactivation of the same LTR by Tat. Transactivation of the human T-cell leukemia virus type I LTR by Tax was also barely influenced. Tax seems to activate NF-kappa B by a mechanism shared with all other inducers of NF-kappa B tested so far. It appears that one of the pleiotropic activities of Tax leads to an enhanced production of oxygen radicals that are required for activation of NF-kappa B.


Interference is controlled by segment 2 and possibly by segment 8 of the nondefective interfering influenza virus variant A/FM/1/47-MA.

On mouse adaption of A/FM/1/47, a variant, A/FM/1/47-MA (FM-MA), that had acquired the properties of increased virulence and interference was produced. Coinfection of cells with FM-MA and prototype strains of influenza virus yielded > 100-fold more FM-MA virus than prototype virus, whereas coinfection with the same prototype strains and the parental A/FM/1/47 virus produced equivalent yields, indicating that FM-MA had acquired mutations that confer the property of interference during mouse adaption. FM-MA is a nondefective interfering virus that grows to a high titer in vivo and in vitro. It has previously been shown that segments 4, 7, and 8 and possibly segment 5 account for the increased virulence. In this study we show by genetic analysis of FM-MA x A/HK/1/68 reassortants that segment 2, coding for the polymerase-associated protein PB1, and possibly segment 8, encoding the NS1 and NS2 proteins, control the ability of FM-MA to interfere. Interference could not be overcome by increasing the titer of the coinfecting strain, but delaying FM-MA infection by 4 to 6 h did avoid interference. During interference of A/HK/1/68, protein synthesis was inhibited by less than 65% throughout coinfection. Given the kinetics of interference and the small perturbation in protein synthesis, interference appeared to occur at the level of late genome replication or virus assembly. Virulence and interference in FM-MA were not linked. An interfering avirulent FM-MA x A/HK/1/68 reassortant, E07, was capable of protecting mice against lethal pneumonia due to a virulent noninterfering reassortant, H04.


Brome mosaic virus RNA replication proteins 1a and 2a from a complex in vitro.

Brome mosaic virus (BMV) is a positive-strand RNA virus that encodes two RNA replication proteins, the helicaselike 1a and the polymeraselike 2a. 1a and 2a share extensive sequence similarities with proteins encoded by many other members of the alphaviruslike superfamily. While further purifying enzymatically active RNA-dependent RNA polymerase from plants infected by BMV, we observed that 1a, 2a, and the polymerase activity all cofractionated through multiple independent purification steps. Moreover, using immunoprecipitation, we found that BMV 1a and 2a proteins synthesized in rabbit reticulocyte lysates or insect cells can form a specific complex in vitro. Complex formation was more efficient when 1a and 2a were cotranslated than when they were mixed after independent synthesis. In an antibody-independent assay, in vitro-translated 1a protein was also found to bind to 2a protein fixed on a nylon membrane. A three-amino-acid insertion in 1a that blocks BMV RNA replication in vivo also blocked in vitro interaction with 2a, while another two-amino-acid insertion that renders the 1a protein temperature sensitive for RNA replication interacted in vitro with 2a at 24 degrees C but not at 32 degrees C. These results and previous genetic data suggest that the 1a-2a interaction observed in vitro is required for BMV RNA replication and may have direct implications for other members of the alphaviruslike superfamily.


Identification of conserved amino acid residues critical for human immunodeficiency virus type 1 integrase function in vitro.

We have probed the structural organization of the human immunodeficiency virus type 1 integrase protein by limited proteolysis and the functional organization by site-directed mutagenesis of selected amino acid residues. A central region of the protein was relatively resistant to proteolysis. Proteins with altered amino acids in this region, or in the N-terminal part of the protein that includes a putative zinc-binding motif, were purified and assayed for 3' processing, DNA strand transfer, and disintegration activities in vitro. In general, these mutations had parallel effects on 3' processing and DNA strand transfer, suggesting that integrase may utilize a single active site for both reactions. The only proteins that were completely inactive in all three assays contained mutations at conserved amino acids in the central region, suggesting that this part of the protein may be involved in catalysis. In contrast, none of the mutations in the N-terminal region resulted in a protein that was inactive in all three assays, suggesting that this part of integrase may not be essential for catalysis. The disintegration reaction was particularly insensitive to these amino acid substitutions, indicating that some function that is important for 3' processing and DNA strand transfer may be dispensable for disintegration.


Mammalian subtilisin-related proteinases in cleavage activation of the paramyxovirus fusion glycoprotein: superiority of furin/PACE to PC2 or PC1/PC3.

The fusion glycoprotein precursor of Newcastle disease virus is ubiquitously cleaved in the constitutive secretory pathway if it possesses an oligobasic cleavage motif (RRQR/KR), whereas the precursor is refractory to cleavage if the motif is monobasic (GR/KQGR). We examined the cleavage activity of the mammalian subtilisin-related proteinases furin/PACE, PC2, and PC1/PC3, which are thought to be responsible for proprotein processing in either the constitutive (furin/PACE) or the regulated (PC2 and PC1/PC3) secretory pathway, for the viral precursors with different cleavage motifs. Only furin/PACE was fully capable of cleaving the precursors with the oligobasic motif. PC2 and PC1/PC3 were incapable or only partially capable of cleaving at this motif. None of the proteinases cleaved the monobasic motif. These results suggest involvement of furin/PACE in viral protein processing in the constitutive secretory pathway.


Subgenomic RNAs mediate expression of cistrons located internally on the genomic RNA of tobacco necrosis virus strain A.

Upon infection of tobacco protoplasts, the genomic RNA of tobacco necrosis virus strain A (TNV-A) accumulates linearly in time. The accumulation patterns of the two subgenomic RNAs resemble those of endogenous mRNAs in that the peak levels are reached after several hours. The accumulation of the 1.3-kb subgenomic RNA is delayed by 1 h compared with that of the 1.6-kb subgenomic RNA, which illustrates the important role of the subgenomic RNAs in the regulation of TNV-A gene expression. The locations of the 5' nucleotides of the subgenomic RNAs reveal that the 5'-proximal cistrons of the 1.6- and 1.3-kb RNAs encode an 8-kDa protein from open reading frame (ORF) 3 and the coat protein from ORF 5, respectively. In a wheat germ translation system, a synthetic transcript resembling the 1.6-kb RNA expresses both ORFs 3 and 4. Moreover, the synthesis of the 6-kDa protein from ORF 4 depends on the translation efficiency of ORF 3, suggesting that in vivo, ORFs 3 and 4 are both expressed from the 1.6-kb RNA. The major in vitro translation product of TNV-A genomic RNA is the coat protein. We show that the region upstream of the coat protein promotes internal initiation of translation in vitro. However, this region is functionally inactive in vivo, suggesting that TNV-A genomic RNA is not important for coat protein synthesis in plants.


Induction of E1A-responsive negative factors for transcription of the fibronectin gene in adenovirus E1-transformed rat cells.

The level of fibronectin (FN) gene expression is very high in resting rat 3Y1 cells but greatly decreased in adenovirus E1-transformed cells. To study the mechanism of this down-regulation, nuclear factors binding to the 5'-flanking region of the FN gene were analyzed by gel retardation assay and DNase I footprinting. Nuclear factors that were present in the transformed cells but nearly absent in resting 3Y1 cells interacted with multiple sites of the promoter region. Oligonucleotide competition with the FN promoter-chloramphenicol acetyltransferase (CAT) reporter constructs (pFCAT) for these factors in the transformed cells indicated that all of them had a negative effect on FN gene expression. Of them, a factor(s) (G10BP) binding to the G10 stretch from positions -239 to -230 and to two GC boxes consisting of the G10 stretch with one internal C residue insertion from positions -105 to -95 and -54 to -44 had the strongest repressive activity. Introduction of substitutive mutations into these G-rich sequences resulted in the increase in CAT activity of pFCAT in the transformed cells. The recognition sequences of G10BP and Sp1 overlap in two GC boxes. G10BP has stronger affinity for heparin and GC boxes than does Sp1, suggesting that G10BP may repress FN gene transcription by displacing Sp1.


Transcription of viral late genes is dependent on expression of the viral intermediate gene G8R in cells infected with an inducible conditional-lethal mutant vaccinia virus.

There are three temporal classes of vaccinia virus genes: early, intermediate, and late. The object of this study was to determine the effects on virus replication of regulating the expression of G8R, an intermediate gene that encodes a late transcription factor. We inserted the lac operator adjacent to the RNA start site of the G8R gene in a recombinant vaccinia virus that constitutively expresses the Escherichia coli lac repressor to make expression of the G8R gene dependent on the inducer isopropyl-beta-D-thiogalactopyranoside (IPTG). In case repression would not be complete, we also weakened the promoter of the G8R gene by making a single-nucleotide substitution designed to reduce its basal level of transcription. The mutant virus replicated well in the presence of the inducer, although synthesis of the G8R-encoded 30,000-M(r) protein was only 10% of that of the wild-type virus. In the absence of IPTG, (i) synthesis of the G8R protein was inhibited by more than 99% relative to that of the wild-type virus, (ii) synthesis of early and intermediate mRNAs appeared to be unaffected, (iii) intermediate proteins accumulated to higher than normal levels, (iv) synthesis of late mRNA and protein was reduced by about 90%, (v) viral DNA was replicated but incompletely resolved concatemeric molecules accumulated, (vi) not even the earliest stages of virion assembly were detectable by transmission electron microscopy, and (vii) virus yield under one-step growth conditions and plaque formation were 10(-3) and 10(-4) times the wild-type values, respectively. The defect in late gene expression could be overcome by transfection of a G8R gene that was not under lac operator control, as well as by addition of IPTG, further demonstrating the specificity of the repression. The correlation between decreased expression of the G8R intermediate gene and inhibition of late mRNA synthesis is consistent with the notion that the G8R product serves as an essential late transcription factor and supports a cascade mechanism of vaccinia virus gene regulation. In addition, the inducer-dependent vaccinia virus mutant provided a tool for selective inhibition of late gene expression while allowing synthesis of early and intermediate mRNAs and proteins.


Epstein-Barr virus latent membrane protein transactivates the human immunodeficiency virus type 1 long terminal repeat through induction of NF-kappa B activity.

The Epstein-Barr virus latent membrane protein (LMP) is an integral membrane protein that is expressed in cells latently infected with the virus. LMP is believed to play an important role in Epstein-Barr virus transformation and has been shown to induce expression of several cellular proteins. We performed a series of experiments that demonstrated that LMP is an efficient transactivator of expression from the human immunodeficiency virus type 1 long terminal repeat (HIV-1 LTR). Mutation or deletion of the NF-kappa B elements in the LTR abolished the transactivation, indicating that the LMP effect on HIV expression was due to induction of NF-kappa B activity. Experiments in which the HIV-1 Tat protein was coexpressed in cells together with LMP showed that Tat was able to potentiate the transactivation. Surprisingly, a synergistic effect of the two proteins was observed even in the absence of the recognized target region for Tat (TAR) in the HIV-1 LTR.


Mutations within the 5' nontranslated region of hepatitis A virus RNA which enhance replication in BS-C-1 cells.

Passage of human hepatitis A virus (HAV) in cell culture results in attenuation of the virus as well as progressive increases in the efficiency of virus replication in cell culture. Because the presence of identical mutations within the 5' nontranslated regions (5'NTRs) of several independently isolated cell culture-adapted HAV variants suggests that the 5'NTR may play a role in determining this change in virus host range, we constructed chimeric infectious cDNA clones in which portions of the 5'NTR of cell culture-adapted HM175/p35 virus were replaced with cDNA from either wild-type virus (HM175/wt) or a second independently isolated, but closely related cell culture-adapted virus (HM175/p16). Substitution of the complete 5'NTR of HM175/p35 with the 5'NTR of HM175/wt resulted in virus with very small replication foci in continuous African green monkey kidney (BS-C-1) cells, indicating that 5'NTR mutations in HM175/p35 virus are required for optimal growth in these cells. A chimera with the 5'NTR sequence of HM175/p16 retained the large foci of HM175/p35 virus, while the growth properties of other viruses having chimeric 5'NTR sequences indicated that mutations at bases 152 and/or 203 to 207 enhance replication in BS-C-1 cells. These findings were confirmed in one-step growth experiments, which also indicated that radioimmunofocus size is a valid measure of virus replication competence in cell culture. An additional mutation at base 687 of HM175/p16 had only a minor role in enhancing growth. In contrast to their effect in BS-C-1 cells, these 5'NTR mutations did not enhance replication in continuous fetal rhesus monkey kidney (FRhK-4) cells. Thus, mutations at bases 152 and/or 203 to 207 enhance the replication of HAV in a highly host cell-specific fashion.


Macrophage-tropic human immunodeficiency virus isolates from different patients exhibit unusual V3 envelope sequence homogeneity in comparison with T-cell-tropic isolates: definition of critical amino acids involved in cell tropism.

Previous experiments indicate that the V3 hypervariable region of the human immunodeficiency virus (HIV) envelope protein influences cell tropism of infection; however, so far no consistent V3 sequence can account for macrophage or T-cell tropism. In these experiments, we studied infectious recombinant HIV clones constructed by using V3 region sequences of HIV isolates from 16 patients to search for sequences associated with cell tropism. Remarkable homology was seen among V3 sequences from macrophage-tropic clones from different patients, and a consensus V3 region sequence for patient-derived macrophage-tropic viruses was identified. In contrast, V3 sequences of T-cell-tropic clones from different patients were highly heterogeneous, and the results suggested that sequence diversity leading to T-cell tropism might be generated independently in each patient. Site-specific mutations identified amino acids at several positions on each side of the GPGR motif at the tip of the V3 loop as important determinants of tropism for T cells and macrophages. However, a wide variety of mutant V3 sequences induced macrophage tropism, as detected in vitro. Therefore, the homogeneity of macrophage-tropic patient isolates appeared to be the result of selection based on a biological advantage in vivo.


Characterization of a baculovirus gene encoding a small conotoxinlike polypeptide.

We identified a gene of Autographa californica nuclear polyhedrosis virus (AcMNPV) that encodes a small cysteine-rich polypeptide which has size and sequence similarity to omega-conotoxins, a class of calcium ion (Ca2+) channel inhibitors, found in the venom of cone snails. Transcriptional analysis indicated that the 159-bp open reading frame, which we named ctl, and a downstream 984-bp open reading frame are transcribed as a single 1.3-kb bicistronic late RNA. The mature ctl gene product was identified as a small secreted protein by high-pressure liquid chromatography fractionation of extracellular fluid. Viruses with a site-specific deletion in ctl appeared normal with regard to the kinetics and virulence of infection, both in vitro and in vivo. Although we studied the behavior of wild-type and mutant virus-infected insects in some detail, a biological role for ctl in AcMNPV infection remains to be established.


Sequence similarity between Borna disease virus p40 and a duplicated domain within the paramyxovirus and rhabdovirus polymerase proteins.

We report the sequence of a Borna disease virus clone (pBDV-40) that encodes a 40-kDa protein (p40) found in the nuclei of infected cells. Comparative sequence analysis indicates that p40 is distantly similar to two different regions in the L-polymerase proteins encoded by paramyxoviruses and rhabdoviruses. The p40 sequence similarity indicates a previously undetected duplication in these viral polymerases. Phylogenetic reconstruction suggests that the gene that encodes p40 last shared a common ancestor with these viral polymerase genes prior to the duplication event. These findings support the hypothesis that Borna disease virus is a negative-strand RNA virus and suggest that p40 is involved in transcription and/or replication. The discovery of a duplication within the polymerase proteins of paramyxoviruses and rhabdoviruses has profound implications for the mapping of enzymatic activities within these multifunctional proteins.


Mutational analysis of the gag-pol junction of Moloney murine leukemia virus: requirements for expression of the gag-pol fusion protein.

The gag-pol polyprotein of the murine and feline leukemia viruses is expressed by translational readthrough of a UAG terminator codon at the 3' end of the gag gene. To explore the cis-acting sequence requirements for the readthrough event in vivo, we generated a library of mutants of the Moloney murine leukemia virus with point mutations near the terminator codon and tested the mutant viral DNAs for the ability to direct synthesis of the gag-pol fusion protein and formation of infectious virus. The analysis showed that sequences 3' to the terminator are necessary and sufficient for the process. The results do not support a role for one proposed stem-loop structure that includes the terminator but are consistent with the involvement of another stem-loop 3' to the terminator. One mutant, containing two compensatory changes in this stem structure, was temperature sensitive for replication and for formation of the gag-pol protein. The results suggest that RNA sequence and structure are critical determinants of translational readthrough in vivo.


Complete nucleotide sequence, genome organization, and biological properties of human immunodeficiency virus type 1 in vivo: evidence for limited defectiveness and complementation.

Previous studies of the genetic and biologic characteristics of human immunodeficiency virus type 1 (HIV-1) have by necessity used tissue culture-derived virus. We recently reported the molecular cloning of four full-length HIV-1 genomes directly from uncultured human brain tissue (Y. Li, J. C. Kappes, J. A. Conway, R. W. Price, G. M. Shaw, and B. H. Hahn, J. Virol. 65:3973-3985, 1991). In this report, we describe the biologic properties of these four clones and the complete nucleotide sequences and genome organization of two of them. Clones HIV-1YU-2 and HIV-1YU-10 were 9,174 and 9,176 nucleotides in length, differed by 0.26% in nucleotide sequence, and except for a frameshift mutation in the pol gene in HIV-1YU-10, contained open reading frames corresponding to 5'-gag-pol-vif-vpr-tat-rev-vpu-env-nef-3' flanked by long terminal repeats. HIV-1YU-2 was fully replication competent, while HIV-1YU-10 and two other clones, HIV-1YU-21 and HIV-1YU-32, were defective. All three defective clones, however, when transfected into Cos-1 cells in any pairwise combination, yielded virions that were replication competent and transmissible by cell-free passage. The cellular host range of HIV-1YU-2 was strictly limited to primary T lymphocytes and monocyte-macrophages, a property conferred by its external envelope glycoprotein. Phylogenetic analyses of HIV-1YU-2 gene sequences revealed this virus to be a member of the North American/European HIV-1 subgroup, with specific similarity to other monocyte-tropic viruses in its V3 envelope amino acid sequence. These results indicate that HIV-1 infection of brain is characterized by the persistence of mixtures of fully competent, minimally defective, and more substantially altered viral forms and that complementation among them is readily attainable. In addition, the limited degree of genotypic heterogeneity observed among HIV-1YU and other brain-derived viruses and their preferential tropism for monocyte-macrophages suggest that viral replication within the central nervous system may differ from that within the peripheral lymphoid compartment in significant and clinically important ways. The availability of genetically and biologically well characterized HIV-1 clones from uncultured human tissue should facilitate future studies of virus-cell interactions relevant to viral pathogenesis and drug and vaccine development.


Fusion mutants of Newcastle disease virus selected with monoclonal antibodies to the hemagglutinin-neuraminidase.

The Australia-Victoria (AV) isolate of Newcastle disease virus (NDV) induces fusion from within but not fusion from without. L1, a neuraminidase (NA)-deficient virus derived from AV, has the opposite fusion phenotype from the wild-type virus. It fails to induce the former mode of fusion, but has gained a limited ability to promote the latter. Monoclonal antibodies to antigenic site 23 on the hemagglutinin-neuraminidase (HN) glycoprotein have previously been shown to select variants of the AV isolate that have altered NA activity or receptor-binding affinity. By using an antibody to this site, variants of L1 have been selected. Three of the variants have gained an increased affinity for sialic acid-containing receptors, as evidenced by the resistance of their hemagglutinating activity to the presence of reduced amounts of sialic acid on the surface of chicken erythrocytes. All four variants still have very low levels of NA activity, comparable to that of the parent virus, L1. The alteration in receptor-binding affinity results in a decreased potential for elution from cellular receptors and correlates with an increased ability to promote both modes of fusion. A single amino acid substitution in the HN protein of each variant, responsible for its escape from neutralization, has been identified. These studies identify two HN residues, 193 and 203, at which monoclonal antibody-selected substitution influences the receptor recognition properties of NDV and may influence its ability to promote syncytium formation.


Oligomerization of hepatitis delta antigen is required for both the trans-activating and trans-dominant inhibitory activities of the delta antigen.

Two forms of hepatitis delta antigen (HDAg) have different roles in the replication cycle of hepatitis delta virus (HDV); the small forms trans activates HDV RNA replication, whereas the large form suppresses it but is needed for virion assembly. To understand the mechanism of these regulatory activities, we studied the possible HDAg oligomerization and its role in HDV replication. In this report, we provide direct biochemical evidence for the in vitro and in vivo formation of homodimers and heterodimers between these two HDAg species. By deletion mutagenesis, we showed that this protein interaction is mediated by the leucine zipper-like sequence residing in the N-terminal one-third of HDAg. Furthermore, site-specific mutants with various substitutions on two of the leucine residues in this stretch of sequence had reduced or no ability to form HDAg dimers. Correspondingly, the small HDAg with mutations in the leucine zipper-like sequence had reduced abilities to trans activate HDV RNA replication. Similar mutations on the leucine zipper-like sequence of the large HDAg also resulted in loss of the ability of large HDAg to inhibit HDV RNA replication. The in vivo biological activities of both forms of HDAg (trans activation and trans-dominant inhibition of HDV RNA replication, respectively) correlated with the extent of HDAg oligomerization in vitro. Thus, we conclude that the small HDAg participates in HDV RNA replication as an oligomer form and that the large HDAg inhibits HDV RNA replication as a result of its complex formation with small HDAg. A "black sheep" model for the mechanism of trans-dominant inhibition by the large HDAg is presented.


Transcriptional analysis of multigene family 110 of African swine fever virus.

A transcriptional analysis of the 3.2-kb region of the African swine fever virus genome containing the five members of the multigene family 110 is presented. The mRNAs corresponding to the genes studied have short leader sequences with no intervening AUG codons before the translational start site, and their 3' ends map within a conserved sequence motif formed by a stretch of seven or more consecutive thymidylate residues. The possible role of this sequence as a signal for the 3'-end formation of African swine fever virus mRNAs is discussed. While four of the genes studied are actively transcribed from the beginning of the infection until the onset of virus DNA replication, the transcription of one of the members of the multigene family 110, the L270 gene, is silenced at an earlier time. A detailed analysis, including in vitro translation of mRNAs isolated from infected Vero cells, revealed that the L270 gene belongs to a small subset of early genes, designated immediate early, whose transcription is silenced before the onset of virus DNA replication. The transcriptional data obtained enabled us to generate the first detailed transcriptional map of a region of the African swine fever virus genome, thus opening the possibility of studying the cis-acting sequences involved in transcriptional control of the viral genes.


Phenotypic progression of a rat lymphoid cell line immortalized by human T-lymphotropic virus type I to induce lymphoma/leukemia-like disease in rats.

Rat lymphoid cells, TARS-1, immortalized by coculture with adult T-cell leukemia cells, were intraperitoneally injected into 65 newborn, inbred WKAH/Hkm rats. In most of the rats, tumor nodules were discernible 7 to 15 days after transplantation but were completely rejected within 5 to 6 weeks. Two rats with no tumor nodules exhibited gait disturbances and paralysis of the hind legs 3 to 4 weeks after transplantation. Histological and hematological examinations revealed that a lymphoma/leukemia-like disease had developed in one of the two rats, and the T-lymphoid cell line WLeuk-1 was established from peripheral blood mononuclear cells from this rat. When the WLeuk-1 cells were transplanted into newborn WKAH/Hkm rats, the animals died of a lymphoma/leukemia-like disease within several weeks after transplantation, in contrast to their rejection of the TARS-1 cells. Southern blot and karyotype analyses revealed that WLeuk-1 cells had retained the marker chromosomes and human T-lymphotropic virus type I (HTLV-I) integration patterns of the parent cell line, TARS-1. The additional specific chromosome abnormalities 3p+,t (12;13), and Xq+ were found in the WLeuk-1 cells. Moreover, the expression of HTLV-I structural proteins was slightly depressed in WLeuk-1 cells, while that of the transacting factors p40tax and p21x, but not that of p27rex, was enhanced about fivefold compared with that in TARS-1. The transactivating function of p40tax was intact in WLeuk-1, as evidenced by enhanced interleukin-2 receptor alpha chain expression. These results suggest that aberrant expression of HTLV-I regulatory genes and alteration of cellular genes were associated with the phenotypic progression of the WLeuk-1 cell line.


A recombinant human Fab expressed in Escherichia coli neutralizes rabies virus.

A recombinant human anti-rabies monoclonal antibody (MAb-57) Fab was prepared by cloning the heavy (Fd)- and light-chain domains into the same bacterial expression vector. To construct the recombinant Fab, mRNA was extracted from MAb-57-producing hybridoma cells, reverse transcribed, and then amplified by polymerase chain reaction (PCR) by using oligonucleotides specific for immunoglobulin heavy- and light-chain DNA sequences. PCR-amplified Fd-chain cDNA was fused, in frame, between a bacterial leader peptide (PelB) at the amino terminus and a 10-amino-acid peptide tag at the carboxy terminus. The PCR-amplified lambda-chain cDNA was also fused to the PelB leader peptide. The immunoglobulin Fab was then expressed as a dicistronic message in bacteria by using the isopropyl-beta-D-thiogalactopyranoside-inducible lactose promotor (lacZ). DNA sequencing was used to define the gamma-chain isotype (immunoglobulin G1) and VH (VHI) chain and VL (V lambda II) chain gene usage. The recombinant Fab (rFab57) specifically bound the rabies virus coat glycoprotein, while the Fd and lambda chains, when expressed individually, did not. The binding specificity of rFab57 was indistinguishable from that of the intact MAb in direct enzyme-linked immunosorbent assays; however, the dissociation constant of rFab57 for rabies virus protein G was approximately 1 log10 U lower than that of complete MAb-57 in competition enzyme-linked immunosorbent assays. A fluorescent-focus inhibition assay showed that bacterially expressed rFab was capable of neutralizing rabies virus strain CVS-11. We conclude that a human Fab expressed in bacteria maintains its specificity and biologic activity.


Coexpression of the simian immunodeficiency virus Env and Rev proteins by a recombinant human adenovirus host range mutant.

Recombinant human adenoviruses (Ads) that replicate in the intestinal tract offer a novel, yet practical, means of immunoprophylaxis against a wide variety of viral and bacterial pathogens. For some infectious agents such as human immunodeficiency virus (HIV), the potential for residual infectious material in vaccine preparations must be eliminated. Therefore, recombinant human Ads that express noninfectious HIV or other microbial proteins are attractive vaccine candidates. To test such an approach for HIV, we chose an experimental model of AIDS based on simian immunodeficiency virus (SIV) infection of macaques. Our data demonstrate that the SIV Env gene products are expressed in cultured cells after infection with a recombinant Ad containing both SIV env and rev genes. An E3 deletion vector derived from a mutant of human Ad serotype 5 that efficiently replicates in both human and monkey cells was used to bypass the usual host range restriction of Ad infection. In addition, we show that the SIV rev gene is properly spliced from a single SIV subgenomic DNA fragment and that the Rev protein is expressed in recombinant Ad-SIV-infected human as well as monkey cells. The expression of SIV gene products in suitable live Ad vectors provides an excellent system for studying the regulation of SIV gene expression in cultured cells and evaluating the immunogenicity and protective efficacy of SIV proteins in macaques.


Maturation cleavage required for infectivity of a nodavirus.

Nodaviral morphogenesis involves formation of labile precursor particles, called provirions, which mature by autocatalytic cleavage of the 407-residue coat precursor protein between asparagine residue 363 and alanine residue 364. It has previously been demonstrated that maturation results in increased physicochemical stability of the virion. We show here that cleavage of coat protein in purified provirions of Flock House virus was accompanied by a five- to eightfold increase in specific infectivity. Cleavage-negative provirions, produced by site-directed mutagenesis of asparagine residue 363 to aspartate, threonine, or alanine, displayed no infectivity above revertant frequencies as measured by plaque assay. All viable revertants (nine of nine) restored asparagine to the mutated position, suggesting high specificity for asparagine at the cleavage site.


Activation of the prolactin receptor gene by promoter insertion in a Moloney murine leukemia virus-induced rat thymoma.

The prolactin receptor (Prlr) and growth hormone receptor (Ghr) genes and the Moloney murine leukemia virus integration-2 (Mlvi-2) locus were mapped to mouse chromosome 15 and human chromosome 5 bands p12-p14. To examine the potential relationship between Mlvi-2 and the genes encoding the growth hormone receptor and the prolactin receptor, we determined the chromosomal location of all three loci in the rat, using a panel of rat-mouse somatic cell hybrids, and in the mouse, using a panel of (C57BL/6J x Mus spretus)F1 x C57BL/6J interspecific backcross mice. These analyses revealed that Ghr, Prlr, and Mlvi-2 map to chromosome 2 in the rat and to chromosome 15 in the mouse, in close proximity with each other. Pulsed-field gel electrophoresis of rat genomic DNA showed no overlaps between the gene encoding the prolactin receptor and the remaining loci. Moreover, expression of the prolactin receptor was not affected by provirus insertion in Mlvi-2. During these studies, however, we detected one T-cell lymphoma line (2779) in which the prolactin receptor gene was activated by provirus integration. Sequence analysis of polymerase chain reaction-derived cDNA clones showed that the prolactin receptor RNA message initiates at the 5' long terminal repeat and utilizes the splice donor site 5' of the gag gene to splice the viral sequences onto exon 1 of the prolactin receptor. This message is predicted to encode the intact prolactin receptor protein product. Exposure of the T-cell lymphoma line 2779 to prolactin promoted cellular proliferation.


An adenosine at position 27 in the human immunodeficiency virus type 1 trans-activation response element is not critical for transcriptional or translational activation by Tat.

Tat protein binds to the trans-activation response (TAR) element of human immunodeficiency virus type 1 RNAs and activates gene expression at the level of transcription in mammalian cell lines and translation in Xenopus oocytes. Certain residues within TAR are important for Tat binding in vitro, including residue A-27, which appears to be able to be modified in a Tat-dependent manner in Xenopus oocytes (L. Sharmeen, B. Bass, N. Sonenberg, H. Weintraub, and M. Groudine, Proc. Natl. Acad. Sci. USA 88:8096-8100, 1991). Activation by Tat in oocytes occurs via a covalent modification of TAR-containing RNA. We have found that in both mammalian cells and Xenopus oocytes, conversion of A-27.U-38 or C-27.G-38 or C-27.G-38 reduces activation. However, conversion to G-27.U-38 or G-27.C-38 had little or no effect on activation, and in oocytes, these mutant RNAs were still covalently modified. These data exclude a specific role for the adenosine at residue 27 for Tat activation but suggest a requirement for a purine at this position.


Protein truncation is not required for c-myb proto-oncogene activity in neuroretina cells.

The v-myb oncogene of avian myeloblastosis virus (AMV) differs from its normal cellular counterpart by a truncation at both its amino and carboxyl termini and by a substitution of 11 amino acid residues. We had previously shown that v-myb-containing AMV, in the presence of basic fibroblast growth factor, transformed chicken neuroretina (CNR) cells. To understand the mechanism of c-myb activation, we have tested whether avian retroviruses that express the full-length c-Myb are also active on CNR cells. We have found that c-Myb, like v-Myb, strongly increases the basic fibroblast growth factor response of CNR cells and that these c-myb-expressing cells are able to grow in soft agar in the presence of the growth factor. We have also found that, in contrast to normal or v-myb-expressing AMV-transformed CNR cells, c-Myb-transformed cells express mim-1, a granulocyte-specific gene. However, normal v-Myb- and c-Myb-expressing CNR cells all express the pax-QNR gene, a newly described paired and homeobox-containing gene specifically expressed in the neuroretina. We conclude that, in contrast to what has been described for hematopoietic cells, overexpression of c-Myb is sufficient to activate gene expression and to induce an abnormal behavior of CNR cells.


Minimal requirements for the human immunodeficiency virus type 1 V3 domain to support the syncytium-inducing phenotype: analysis by single amino acid substitution.

The third variable domain (V3) of the human immunodeficiency virus type 1 external envelope contains determinants of cell tropism, cytopathicity, and infectivity and elicits antibodies able to block infectivity in vitro and in vivo. Our study encompassed point-mutational analysis of HXB-2 viruses containing patient-derived V3 regions and expressing a non-syncytium-inducing, low-replicating phenotype in T-cell line SupT1. The mutation within V3 of a serine at position 306 into an also naturally occurring arginine (S to R) required an additional, naturally occurring mutation at position 320 (aspartate to glutamine, D to Q) or 324 (aspartate to asparagine, D to N) for full expression of the syncytium-inducing, high-replicating (SI) phenotype. The naturally occurring mutation of an aspartate into an arginine at position 320 (D to R) was sufficient for production of the SI phenotype. This study proves that introduction of a positively charged amino acid at position 306 or 320, previously shown to be strongly associated with the SI phenotype in field isolates (R.A.M. Fouchier, M. Groenink, N.A. Kootstra, M. Tersmette, H.G. Huisman, F. Miedema, and H. Schuitemaker, J. Virol. 66:3183-3187, 1992), is minimally required for production of SI viruses. In addition, naturally occurring mutations at residue 324 also modulate the virus phenotype.


Human immunodeficiency virus type 1 gag-protease fusion proteins are enzymatically active.

We have introduced mutations into the region of the genome of human immunodeficiency virus type 1 (HIV-1) that encodes the cleavage sites between the viral protease (PR) and the adjacent upstream region of the polyprotein precursor. Segments containing these mutations were introduced into plasmids, and the retroviral proteins were expressed in Escherichia coli. The mutations prevented cleavage between the PR and the adjacent polypeptide; however, other PR cleavage sites in the polyprotein were cleaved normally, showing that the release of free PR is not a prerequisite for the appropriate processing of HIV-1 precursors.


Restoration of cell surface CD4 expression in human immunodeficiency virus type 1-infected cells by treatment with a Tat antagonist.

Productive infection of T lymphocytes with human immunodeficiency virus type 1 (HIV-1) is accompanied by a diminution of surface CD4 receptors. Treatment of chronically HIV-1-infected CD4-negative T cells in vitro with the Tat antagonist Ro 5-3335 resulted in a drug dose-dependent decrease in virus protein production and a reciprocal increase in surface CD4 display. The drug-treated cells remained viable, showed significantly reduced levels of the full-length and spliced HIV-1 mRNAs as detected by Northern (RNA) blot hybridization, and maintained integrated HIV-1 DNA. In immunoprecipitation studies with drug-treated cells, the levels of free 55-kDa CD4 protein increased and gp160 complexed with CD4 decreased in amount. These results show for the first time that certain cytopathogenic effects of chronic HIV-1 infection can be reversed by suppressing virus expression.


Transcription of human respiratory syncytial virus genome RNA in vitro: requirement of cellular factor(s).

Extracts made from human respiratory syncytial virus (RSV)-infected Hep-2 cells synthesized mRNAs encoded by all known viral genes. In contrast, RSV ribonucleoproteins purified from infected cells failed to transcribe in vitro; transcription was restored by addition of a cytoplasmic extract of uninfected Hep-2 cells, demonstrating that a cellular factor(s) has a role in RSV gene expression. Quantitation of the individual gene mRNAs transcribed in vitro revealed polarity of transcription of the genome.


Genetic recombination in brome mosaic virus: effect of sequence and replication of RNA on accumulation of recombinants.

In order to facilitate the isolation of recombinants in brome mosaic virus, a series of duplication mutants with alterations in the RNA3 3' noncoding region has been engineered. The distribution of crossovers, which was observed to be dependent on the parental RNA3 sequence, supported the role of RNA structure in recombination. However, a negative correlation between replication of the parental RNA3 constructs and the accumulation of recombinant progeny confirmed the role of selection.


Baculovirus gp64 envelope glycoprotein is sufficient to mediate pH-dependent membrane fusion.

The baculovirus gp64 envelope glycoprotein is a major component of the envelope of the budded virus (BV) and is involved in BV entry into the host cell by endocytosis. To determine whether gp64 alone was sufficient to mediate membrane fusion, the Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus gp64 protein was transiently expressed in uninfected insect cells. Cells expressing the baculovirus gp64 protein were examined for membrane fusion activity by using a syncytium formation assay under various conditions of exposure to low pH. Cells expressing the gp64 protein mediated membrane fusion and syncytium formation in a pH-dependent manner. A pH of 5.5 or lower was required to induce membrane fusion. In addition, exposure of gp64-expressing cells to low pH for as little as 5 s was sufficient to induce gp64-mediated syncytium formation. These studies provide direct evidence that gp64 is a pH-dependent membrane fusion protein and suggest that gp64 is the protein responsible for fusion of the virion envelope with the endosome membrane during BV entry into the host cell by endocytosis.


Laparoscopic operative retroperitoneoscopy: use of a new device.

Attempts at retroperitoneoscopy have mostly failed in the past due to the inability to create an effective pneumoretroperitoneum because of the dense areolar tissue binding the fat in the retroperitoneum, which could not be broken down merely by pneumo-insufflation. The newly devised balloon breaks the septae, lifts the peritoneum atraumatically and creates a workable space in the retroperitoneum. The view of the retroperitoneal structures provided is satisfactory. With this balloon dissector we have performed laparoscopic ureterolithotomy, renoscopy and renal biopsy, para-aortic lymph node biopsy and ligation of the internal spermatic vein.


Laparoscopic cystectomy: initial report on a new treatment for the retained bladder.

The retained bladder of a 27-year-old paraplegic woman suffering from recurrent pyocystis was removed laparoscopically. Operative time was 130 minutes. Postoperative hospital stay was 5 days, which was significantly less than that in 5 similar patients undergoing open cystectomy for vesical empyema in whom the mean hospital stay was 20.6 days. We believe that laparoscopic cystectomy represents a plausible, minimally invasive alternative to standard cystectomy for the symptomatic bladder left behind after supravesical urinary diversion.


Stimulated release of urine histamine in interstitial cystitis.

The diagnosis of interstitial cystitis is primarily made based on clinical and cystoscopic findings with exclusion of other bladder diseases. Despite all of the efforts at definitive identification, interstitial cystitis lacks universal objective findings. Mast cell activation with associated histamine release has been postulated as an etiological factor leading to the symptom complex associated with interstitial cystitis. To investigate this hypothesis, a 3-step controlled prospective study was conducted. In step 1 reliability of urine histamine assay was critically examined, and the assay was established to be simple, reliable and valid. In step 2 random spot urine histamine levels (basal state) were measured in 25 noninterstitial cystitis and 15 interstitial cystitis patients (22.1 +/- 0.95 ng./ml. versus 19.2 +/- 1.19 ng./ml.). There was no significant difference in the random urine histamine levels between the 2 groups (p greater than 0.05). In step 3 urine histamine levels were measured before and after hydrodistention (acute stimulation) in 7 noninterstitial cystitis controls and 6 newly diagnosed interstitial cystitis patients under general anesthesia. The urine histamine-to-creatinine ratio was used to correct for the dilutional effect of normal saline used during hydrodistention. The urine histamine-to-creatinine ratios of the control group showed no significant difference before and after hydrodistention. However, the difference in the urine histamine-to-creatinine ratios of the interstitial cystitis group compared to the controls before and after hydrodistention was highly significant (p less than 0.001). Although measurement of random spot urine histamine alone (basal state) was not found useful to make the diagnosis of interstitial cystitis, measurement of urine histamine before and immediately after hydrodistention (acute stimulation) may become an important objective parameter to assist in the diagnosis of interstitial cystitis.


Monoclonal antibody Ki-67 in the study of the proliferative activity of bladder carcinoma.

We studied the proliferative activity of bladder carcinoma using monoclonal antibody Ki-67, which is able to stain a nuclear antigen exclusively present in cells in the cell cycle, that is with activated deoxyribonucleic acid (DNA). We used this immunohistochemical technique on neoplastic tissue removed by transurethral resection from 101 patients. A significant correlation was observed (p less than 0.003) between cells with activated DNA and histological grading, even though within the context of each grade we observed tumors with a different proliferation index. Furthermore, we studied the location of the activated cells in the context of the tumor. In invasive tumors (stages T1 to T4) cells with activated DNA were always present at the base of implant of the tumor and in the neoplastic tissue that infiltrates the bladder wall. In regard to noninvasive tumors (stage Ta), in 57% of the cases most cells with activated DNA were present in the vegetative portion of the tumor and there were no recurrences at followup, while in 43% of the cases such cells were present also or especially at the base of implant of the tumor, near the lamina propria. In the latter patients we observed a 94% recurrence rate. These results suggest that the immunohistochemical assessment of the proliferative activity of transitional tumors of the bladder, using monoclonal antibody Ki-67, and the evaluation of the location of stained neoplastic cells provide a more reliable estimate of biological aggressiveness than that obtained with histopathological patterns alone.


Whole bladder wall photodynamic therapy with in situ light dosimetry for carcinoma in situ of the bladder.

We report on the preliminary results of 12 patients with multifocal carcinoma in situ of the bladder treated with whole bladder wall photodynamic therapy. The total light dose (scattered plus nonscattered light) measured in situ was 100 joules per cm.2 in the first 6 patients (group 1) and 75 joules per cm.2 in the remaining 6 (group 2). These light doses correspond on the average to 27 joules per cm.2 and 15.5 joules per cm.2 nonscattered light as reported by other investigators. Followup ranged from 6 to 22 months (average 11.5). In group 1, 2 tumors recurred after 6 and 9 months, respectively, and 2 other patients had a permanently shrunken bladder without evidence of disease. In group 2, 1 tumor recurred 5 months after photodynamic therapy. In this group the bladder capacity increased on the average to 135% of the pretreatment value 3 months after photodynamic therapy. All recurrences were in patients with a history of invasive bladder cancer (stages T1 and T2). These preliminary results demonstrate the importance of in situ scattered light dosimetry for minimizing local side effects of whole bladder photodynamic therapy.


Urethral controlled bladder substitution: a comparison between the intussuscepted nipple valve and the technique of Le Duc as antireflux procedures.

A urethral controlled bladder substitute was constructed from a detubularized, double folded ileal segment in 40 male patients following cystoprostatectomy for bladder cancer. For reflux prevention patients were prospectively randomized to receive either an intussuscepted nipple valve or the ureters were implanted by the Le Duc mucosal trough technique. All patients had normal upper tracts preoperatively. Mean patient age, performance status and stage of cancer were comparable in both groups. Patients were evaluated 6 to 18 months postoperatively. In addition to history taking, assessment included excretory urography, ascending cystography and voiding cystourethrography. During the observation period all patients with nipple valves had normal radiographic appearance of the upper tracts without evidence of reflux. On the other hand, following the Le Duc procedure 12 of 38 renal units (31%) showed evidence of radiographic dilatation. Of the 12 units 11 had stenotic ureters and 1 had reflux. We conclude that nipple valves are more effective in reflux prevention and protection of the upper urinary tract in patients for whom an ileal neobladder is indicated.


Magnetic resonance imaging of traumatic posterior urethral defects and pelvic crush injuries.

A total of 18 patients 4 to 71 years old with complete occlusion of the prostatomembranous urethra from pelvic crush injury underwent magnetic resonance imaging (MRI) of the pelvis just before open urethroplasty. MRI studies included T2-weighted sagittal and coronal images as well as transaxial T1 and T2-weighted spin-echo images. Operative findings and erectile function were correlated with MRI findings. All patients underwent conventional cystography and retrograde urethrography. The mean interval from injury to operation was 5.5 months (range 3 to 12 months) and followup averaged 12 months (range 3 to 40 months). Posttraumatic pelvic anatomy can be distorted and imaging in all 3 planes was needed. The severity and direction of prostatourethral dislocation, and the length of the urethral defect could be accurately determined, which often is not possible with conventional radiographic studies. MRI also demonstrated injuries at many locations along the erectile pathway, including sacral and ischial fractures as well as fractures and avulsions of the cavernous bodies. Pelvic MRI can accurately define the pelvic anatomy after crush injury and, therefore, it can provide useful preoperative information that cannot be obtained by conventional radiographic studies. Our results correlating MRI findings of cavernous avulsion with clinical impotence require further study.


Successful outcome of artificial urinary sphincters in men with post-prostatectomy urinary incontinence despite adverse implantation features.

A total of 75 men with post-prostatectomy urinary incontinence underwent artificial urinary sphincter implantation with a mean followup of 3.7 years. Average patient age at implantation was 67 years, with 30 men being 70 years old or older. In only 15 men (20%) was there no adverse implantation feature, while the remainder had adverse features, such as detrusor hyperactivity (44), bladder neck or urethral stricture disease (27), previous radiation therapy (11) and metastatic prostate cancer (11). Although men with ideal implantation characteristics, men with normal detrusors and men who underwent prostatectomy for benign disease had slightly better outcome in terms of urinary continence, in general each group of men with and without adverse features had satisfactory urinary continence. Other than men with a benign prostate, who fared better, each group of men with and without adverse features had equal need for device revisions. In conclusion, men with post-prostatectomy urinary incontinence should not be excluded from consideration for artificial urinary sphincter implantation based on the failure to meet ideal implantation criteria provided such adverse features are recognized and appropriately addressed.