Polymerase chain reaction can resolve some undefined cases of hepatitis B virus antigenic subtyping

HBsAg subtypes were defined by means of adsorbed polyclonal antisera; however, HBsAg subtyping is currently usually carried out with monoclonal antibodies (Mab). We developed a complementary subtyping method based on the polymerase chain reaction. Reference samples belonging to all known HBsAg subtypes could be detected and grouped into four different categories (ayw1/ayw4/ayr, ayw2/ayw3, adw2/adrq+/adrq-, adw4). Thirteen HBsAg-positive serum samples previously subtyped as ad by means of monoclonal antibodies fell into the adw2/adrq+/adrq- group, as well as 13 ay samples into the ayw2/ayw3 group. These results could be confirmed by means of reference polyclonal antisera in nine ad cases (all adw2) and in seven ay cases (all ayw3); the remaining seven were below the detection limit of the polyclonal assay. Four samples which were not recognized by any of the d/y subtype-specific Mab were shown to contain ayw2/ayw3 sequences. Only one contained sufficient HBsAg to be confirmed as ayw3 by means of reference antisera. Three of five sera showing simultaneous reactivity both for d and y-specific Mab were classified as adw4 by PCR, as was one by reference polyclonal antisera. The y-specific monoclonal antibody cross-reacted with the adw4 subtype. Single adw2 sequences were amplified in one of the remaining two cases, as well as single ayw2/ayw3 sequences in the other, suggesting that they showed true coexistence of two strains of different subtype, only one of which was in active replication state. It is concluded that the method described is useful in the solution of some undefined cases obtained with the monoclonal-based assays.

Detection and typing of human herpesviruses by multiplex polymerase chain reaction

A new approach to simultaneous detection and typing of related agents by the multiplex polymerase chain reaction (PCR) is described. The reaction was been applied to human herpesviruses by nested amplification of fragments of the DNA polymerase genes. During the first amplification, primers were used as two equimolar mixtures of non-degenerate oligonucleotides, aligning the 3'-ends with selected consensus regions, and their 5'-ends with the non-related sequences of each herpesvirus to be amplified. The specific fragments obtained were the substrate for a second, multiplex reaction for which primers were designed to produce different-size fragments for each related virus. The results showed high specificity for the detection and typing of the human herpesviruses with known sequences and no amplification of human DNA, in spite of the presence of the same consensus regions within human DNA polymerase alpha. It is concluded that this new approach would be useful for the differential diagnosis of herpesviruses, as well as for other groups of agents with conserved regions in their genomes and causing similar syndromes.

Role of surgery in the management of pulmonary sporotrichosis

Management of four patients with sporotrichosis is summarized; one was treated medically and three were treated surgically. Thirty-seven cases from the literature are reviewed. The role of surgery in the management of pulmonary sporotrichosis is outlined as follows: (1) diagnosis of pulmonary infiltrates and/or pulmonary cavities of undetermined origin, (2) surgical intervention in patients with persistent infiltrates with cavitary lesions resulting from sporotrichosis, following failed medical treatment, and (3) resection of associated pulmonary cavitary lesions in patients in spite of adequte medical control of sporotrichosis. Surgical principles that must be observed in the management of pulmonary sporotrichosis follows:(1) Resection is the procedure of choice. The magnitude ranges from segmental resection to pneumonectomy. Clean resection is necessary. (2) Antifungal drug therapy--preferably with amphotericin B--is advisable preoperatively and postoperatively, since the major cause of late death is progression of the disease when clean resection has not been feasible. (3) Resection combined with drug therapy can be curative without increased risk in physiologically operable and anatomically resectable disease. (4) Thoracoplasty can be a lifesaving procedure for bilateral cavitary lesions with severe hemoptysis in patients with impaired pulmonary functions.