Phasic venous return abnormality in chronic pulmonary diseases: pulsed Doppler echocardiography study

Features of venous return in chronic pulmonary diseases and factors determining such features were studied by analysis of respiration-related variation in the superior vena cava flow on pulsed Doppler echocardiography. Subjects of this study were 85 patients with chronic pulmonary diseases; 54 healthy subjects served as normal controls. In the healthy subjects, the velocity of the S and D waves increased during inspiration (type I pattern), and the velocity of the A wave increased during expiration. In the patients with pulmonary diseases, the pattern of the superior vena cava flow was either type I or type II (disappearance of the D wave or disappearance of both the D and S waves). The incidence of the type II pattern was significantly higher in the patients showing a reduction of both FEV1.0% and % VC. The respiration-related variation in the superior vena cava flow pattern was found to be determined by the pressure fall between right atrium and subclavian vein. A type II pattern was attributed to the elevation of right atrial pressure caused by positive pleural pressure. The velocity of the A wave increased during expiration, showing a good correlation with pulmonary vascular resistance. Venous return in the presence of chronic pulmonary disease was found to be affected by the type of ventilatory disturbance and intensity of pulmonary vascular resistance.

Structure and expression of mRNA for vitellogenin in Bombyx mori

Vitellogenin, a precursor of major yolk protein of the silkworm, Bombyx mori is a tetramer composed of each two molecules of heavy and light subunits. We cloned mRNA sequence for the B. mori vitellogenin and analyzed its structure. Sequence alignment of several overlapping cDNA clones indicated that the vitellogenin mRNA is approx. 5.7 kb, containing an open reading frame for a peptide with 1782 amino acid residues. By comparing the deduced amino acid sequence with the amino-terminal primary structures of vitellogenin subunits, it is suggested that the heavy and light subunits of the B. mori vitellogenin are encoded by a single contiguous mRNA. The primary translation product of the vitellogenin mRNA was detected in the microsomal fraction prepared from the fat body of vitellogenic females. Northern blot analysis of the fat body RNA demonstrated that the biosynthesis of vitellogenin in B. mori is regulated in a tissue-, sex- and stage-specific manner at the level of mRNA. Possible cause for discrepancy between the present results and our previous proposal (Izumi, S. and Tomino, S. (1983) Insect Biochem. 13, 81-85) on the biosynthesis of B. mori vitellogenin is also discussed.

Structure and developmental expression of a larval cuticle protein gene of the silkworm, Bombyx mori

Structure and expression of the gene for a larval cuticle protein of the silkworm, Bombyx mori were studied. A major cuticle protein, termed 'LCP30' was purified from the urea extract of integuments of the fifth (final) instar larvae. Immunoblot analysis by use of the anti-LCP30 antibody revealed that LCP30 begins to accumulate in larvae as early as 10 h after hatch and is present throughout the larval stages. The LCP30 epitope is also detectable in the adult abdominal integument but is absent from pupal integument and adult wing. Screening of an epidermal cDNA expression library with the antibody probe yielded a cDNA clone for LCP30. Primary structure deduced from the cDNA sequence showed that LCP30 bears an arginine-glycine-aspartate (RGD) sequence. The region around this domain exhibits striking similarity with the amino acid sequences found in vertebrate collagens. The genomic DNA clone coding for LCP30 was isolated by screening a B. mori gene library with the LCP30 cDNA probe. The gene consists of five exons interspersed by four introns spanning over 2.7 kb region of chromosomal DNA. The LCP30 mRNA is detectable at high levels at larval intermolt stages, gradually declines after the fourth molt and totally disappears at mid-fifth larval instar, indicating that the expression of LCP30 gene is regulated in a stage-specific fashion in the epidermal cells. Topical application of a juvenile hormone analogue (methoprene) to the fifth instar larvae followed by RNA blot and S1 nuclease mapping analyses of the epidermal RNA proved that juvenile hormone activates transcription of the LCP30 gene.

Cancer incidence in atomic bomb survivors. Part III. Leukemia, lymphoma and multiple myeloma, 1950-1987

This paper presents an analysis of data on the incidence of leukemia, lymphoma and myeloma in the Life Span Study cohort of atomic bomb survivors during the period from late 1950 through the end of 1987 (93,696 survivors accounting for 2,778,000 person-years). These analyses add 9 additional years of follow-up for leukemia and 12 for myeloma to that in the last comprehensive reports on these diseases. This is the first analysis of the lymphoma incidence data in the cohort. Using both the Leukemia Registry and the Hiroshima and Nagasaki tumor registries, a total of 290 leukemia, 229 lymphoma and 73 myeloma cases were identified. The primary analyses were restricted to first primary tumors diagnosed among residents of the cities or surrounding areas with Dosimetry System 1986 dose estimates between 0 and 4 Gy kerma (231 leukemias, 208 lymphomas and 62 myelomas). Analyses focused on time-dependent models for the excess absolute risk. Separate analyses were carried out for acute lymphocytic leukemia (ALL), acute myelogenous leukemia (AML), chronic myelocytic leukemia (CML) and adult T-cell leukemia (ATL). There were few cases of chronic lymphocytic leukemia in this population. There was strong evidence of radiation-induced risks for all subtypes except ATL, and there were significant subtype differences with respect to the effects of age at exposure and sex and in the temporal pattern of risk. The AML dose-response function was nonlinear, whereas there was no evidence against linearity for the other subtypes. When averaged over the follow-up period, the excess absolute risk (EAR) estimates (in cases per 10(4) PY Sv) for the leukemia subtypes were 0.6, 1.1 and 0.9 for ALL, AML and CML, respectively. The corresponding estimated average excess relative risks at 1 Sv are 9.1, 3.3 and 6.2 respectively. There was some evidence of an increased risk of lymphoma in males (EAR = 0.6 cases per 10(4) PY Sv) but no evidence of any excess in females. There was no evidence of an excess risk for multiple myeloma in our standard analyses.

Cancer incidence in atomic bomb survivors. Part II: Solid tumors, 1958-1987

This report presents, for the first time, comprehensive data on the incidence of solid cancer and risk estimates for A-bomb survivors in the extended Life Span Study (LSS-E85) cohort. Among 79,972 individuals, 8613 first primary solid cancers were diagnosed between 1958 and 1987. As part of the standard registration process of the Hiroshima and Nagasaki tumor registries, cancer cases occurring among members of the LSS-E85 cohort were identified using a computer linkage system supplemented by manual searches. Special efforts were made to ensure complete case ascertainment, data quality and data consistency in the two cities. For all sites combined, 75% of the cancers were verified histologically, 6% were diagnosed by direct observation, 8% were based on a clinical diagnosis, and 12.6% were ascertained by death certificate only. A standard set of analyses was carried out for each of the organs and organ systems considered. Depending on the cancer site, Dosimetry System 1986 (DS86) organ or kerma doses were used for computing risk estimates. Analyses were based on a general excess relative risk model (the background rate times one plus the excess relative risk). Analyses carried out for each site involved fitting the background model with no dose effect, a linear dose-response model with no effect modifiers, a linear-quadratic dose-response model with no effect modifiers, and a series of linear dose-response models that included each of the covariates (sex, age at exposure, time since exposure, attained age and city) individually as effect modifiers. Because the tumor registries ascertain cancers in the registry catchment areas only, an adjustment was made for the effects of migration. In agreement with prior LSS findings, a statistically significant excess risk for all solid cancers was demonstrated [excess relative risk at 1 Sv (ERR1Sv) = 0.63; excess absolute risk (EAR) per 10(4) person-year sievert (PY Sv) = 29.7]. For cancers of the stomach (ERR1SV = 0.32), colon (ERR1SV = 0.72), lung (ERR1SV = 0.95), breast (ERR1SV = 1.59), ovary (ERR1SV = 0.99), urinary bladder (ERR1SV = 1.02) and thyroid (ERR1SV = 1.15), significant radiation associations were observed. There was some indication of an increase in tumors of the neural tissue (excluding the brain) among persons exposed to the bombs before age 20. For the first time, radiation has been associated with liver (ERR1SV = 0.49) and nonmelanoma skin (ERR1SV = 1.0) cancer incidence in the LSS cohort. The present analysis also strengthened earlier findings, based on a smaller number of cases, of an effect of A-bomb radiation on salivary gland cancer.(ABSTRACT TRUNCATED AT 400 WORDS)

Characterizations of sea urchin fibrillar collagen and its cDNA clone

Collagens were isolated from the adult test of the sea urchin species, Hemicentrotus pulcherrimus and Strongylocentrotus purpuratus, and their molecular properties were compared with those of Asthenosoma ijimai collagen. Collagens from H. pulcherrimus and S. purpuratus comprised two major alpha-chains (alpha 120 and alpha 90) and a minor chain (alpha 140), while collagen from A. ijimai contained four alpha-chains (alpha 1, alpha 2, alpha 3 and alpha 4). Based on their molecular and immunological properties, the alpha 90 chain of H. pulcherrimus and S. purpuratus, and the alpha 2 and alpha 4 chains of A. ijimai are grouped together, while the alpha 120 and alpha 140 chains of H. pulcherrimus and S. purpuratus, and the alpha 1 and alpha 3 chains of A. ijimai are classified into another group. It is likely that collagen molecules of sea urchins are heterotrimers composed of these two types of alpha-chains. A cDNA of collagen was cloned from the cDNA library prepared from mRNA of H. pulcherrimus test and denoted as Hpcol1. This clone contained sequences for uninterrupted triple helical domain (378 amino acids), carboxyl telopeptide (28 amino acids) and carboxyl propeptide (225 amino acids). This structure is characteristic for fibril-forming collagens and was shown to encode alpha 120 and alpha 140 chains of H. pulcherrimus collagen. Hpcol1-mRNA was expressed in embryos as early as the prism stage.

An epidemiological study of leprosy infection by serology and polymerase chain reaction

A population-based study has been carried out in two adjacent villages in a highly leprosy-endemic area of South Sulawesi, Indonesia. The prevalence of clinical leprosy was 10.0 per 1000 inhabitants. A total of 1015 serum samples and 1228 nasal swab specimens were collected. IgM antibodies in blood to phenolic glycolipid-I (PGL-I) of Mycobacterium leprae were demonstrated by the gelatin particle agglutination test (MLPA) and by indirect ELISA (IgM-PGL). IgG antibodies to PGL-I (IgG-PGL) and lipoarabinomannan-B (IgG-LAM) were measured by indirect ELISA. The presence of M. leprae in nasal swab specimens was established by a polymerase chain reaction (PCR). The seropositivity rates in the population were 32% for MLPA, 30.8% for IgM-PGL, 6.7% for IgG-PGL, and 11.6% for IgG-LAM. Seropositivity rates for MLPA and IgM-PGL were highest in the younger age groups. There was no difference in seropositivity in any of the tests between household contacts of leprosy patients and noncontacts. The seropositivity rates in the MLPA and IgM-PGL were not randomly distributed among all households. The presence of M. leprae by PCR was demonstrated in 7.8% of the nasal swab specimens. No correlation was found between the results of the PCR and serology. This study indicates that M. leprae is widespread in the population, and that in endemic areas many individuals carry M. leprae in their nasal cavities without having obvious symptoms of leprosy.

[Contrast echocardiographic detection of pulmonary arteriovenous shunt in a hypoxemic patient with liver cirrhosis]

A 62-year-old man with liver cirrhosis and hypoxemia was admitted to evaluate the etiology of hypoxemia. The patient had noticed exertional dyspnea for three years. Physical examination, laboratory tests, ultrasonography and liver scintigraphy revealed liver cirrhosis. The arterial blood gas test showed hypoxemia (PO2 46.3 mmHg). Chest roentgenogram showed old pulmonary tuberculosis and the pulmonary function test demonstrated decreased FEV 1.0% and %DLco, which did not account for the marked hypoxemia. Contrast echocardiography was performed by injecting hand-agitated saline into the antecubital vein. Three seconds after the right ventricle was opacified, the contrast echoes appeared in the left atrium and then the left ventricle. Pulmonary arteriography revealed no pulmonary arteriovenous fistula. Hemodynamic data showed low pulmonary vascular resistance. Contrast echocardiography by injecting hand-agitated saline from the catheter tip was performed at both pulmonary arteries and the left atrium was opacified by each injection. The hypoxemia was mainly attributed to a intrapulmonary arteriovenous shunt. Although the etiology of hypoxemia in liver cirrhosis seems to be multifactorial, the intrapulmonary arteriovenous shunt is the most important factor. Contrast echocardiography was useful for detecting this shunt.

Laparoscopic study of peliosis hepatis and nodular transformation of the liver before and after renal transplantation: natural history and aetiology in follow-up cases

Although peliosis hepatis and nodular transformation of the liver can occur after renal transplantation, their prevalence has not been well defined. To investigate the incidence of these complications, 137 laparoscopies were studied, 52 in 50 cases before and 85 in 66 cases after renal transplantation. To elucidate the aetiology and natural history of these diseases, cases were followed up by repeated laparoscopies. Peliosis was observed after transplantation (before: n = 1, after: n = 15 [22%], p < 0.005). Nodular transformation was seen only after transplantation (n = 5 [7%]), and was accompanied by peliosis (n = 4, p < 0.01). On observation before and after transplantation in the same cases, these diseases appeared after transplantation (peliosis: n = 9, p < 0.005; nodular transformation: n = 2). In follow-up cases, these diseases were confirmed after the discontinuation of or the controlled administration of immunosuppressants. The aetiology of the micronodular transformation which appeared following peliosis in a case treated without cyclosporin was shown to be azathioprine. However, the macronodular transformation observed in two cases treated with both azathioprine and cyclosporin seemed to be due to cyclosporin. This suggests that cases of peliosis hepatis and nodular transformation which appear after renal transplantation are associated with immunosuppressants, and that cyclosporin treatment may also affect the morphogenesis of nodular transformation.

Activation of the fibrinolytic system in patients with fulminant liver failure

Abnormalities of blood coagulation and fibrinolysis are a major part of fulminant liver failure. In this study, the key components of the fibrinolytic system were determined in 42 patients with this condition. Admission levels of plasma plasminogen activity were low (9.1% of normal), as to a lesser extent were the activities of its inhibitors alpha 2-antiplasmin (20.5% of normal) and C1 inhibitor (64% of normal). Tissue plasminogen activator activity was found at normal levels, whereas the level of its fast inhibitor, plasminogen activator inhibitor-1, was greatly increased compared with that of controls (24.3 U/ml and 7.4 U/ml, respectively), indicating a shift toward inhibition of fibrinolysis in these patients. Thrombin-antithrombin complex levels in plasma were significantly increased in fulminant liver failure compared with those in controls (33.5 micrograms/L vs. 2.5 micrograms/L, p < 0.001), indicating activation of coagulation in these patients. High plasma levels of D-dimer, a fragment of cross-linked fibrin, were also found (1,510 micrograms/L vs. 33 micrograms/L in controls, p < 0.001); this finding correlated with the increased level of thrombin-antithrombin complex (r = 0.61, p < 0.001), consistent with activation of fibrinolysis resulting from intravascular coagulation. In conclusion, there are gross abnormalities of the fibrinolytic system in fulminant liver failure, but because inhibitory activity appears to be present in adequate quantities, this limits the incidence of bleeding due to fibrinolysis.

FR901459, a novel immunosuppressant isolated from Stachybotrys chartarum No. 19392. Taxonomy of the producing organism, fermentation, isolation, physico-chemical properties and biological activities

FR901459, a novel immunosuppressant, has been isolated from the fermentation broth of Stachybotrys chartarum No. 19392. The molecular formula of FR901459 was determined as C62H111N11O13. FR901459 was found to be a member of the cyclosporin family. However, it is structurally distinct from any other cyclosporins discovered so far, in that Leu is present at position 5 instead of Val. FR901459 was capable of prolonging the survival time of skin allografts in rats with one third the potency of cyclosporin A.

Concurrent ovarian serous carcinoma and osteogenesis imperfecta

Because epithelial malignancies in patients with osteogenesis imperfecta are rare, it has been postulated that these patients may have "cancer-protection". A case of stage III b ovarian serous carcinoma in a woman with congenital osteogenesis imperfecta is now presented and discussed.

[Successful canine bilateral single lung allotransplantation after 21-hours lung preservation with low potassium dextran glucose (LPDG) solution]

We evaluated the lung preservation with LPDG solution using a canine bilateral single lung transplantation (BSLT). The donor lung was flushed with LPDG solution, inflated with 100% oxygen and preserved at 8 degrees C. The recipient dogs were divided into two groups. In group I, lungs were implanted after a short total ischemic time (TIT) (TIT in the right lung: 3 hrs and 9 +/- 28 min: TIT in the left lung: 6 hrs and 2 +/- 33 min) and in group II, lungs were implanted after a long TIT (right: 18 hrs and 11 +/- 28 min: left: 21 hrs and 6 +/- 21 min). During 12 hrs after BSLT (using respirator, FiO2 = 1.0), the PaO2 level was 500-600 mmHg, indicating satisfactory respiratory function in both groups with no significant differences. There were no significant differences in the mPAP level between the two groups, and the result indicated satisfactory pulmonary circular dynamics. Following the 12 hrs period of post-transplant assessment, the animals were extubated. All five in group I and 4 out of 6 in group II survived by autonomous respiration. The maximum survival period in group I was 4 days and that in group II was 8 days. After 24 hrs of extubation, mean PaO2 and PaCO2 level was as high as 84.4 +/- 11.2 mmHg and 23.8 +/- 0.2 mmHg in group I (n = 2), and 79.1 +/- 0.2 mmHg and 37.2 +/- 1.0 mmHg in group II. The subject which survived for 8 days showed satisfactory respiratory function postoperatively until it died.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of trace amounts of phosphate in water after preconcentration using a thermally reversible polymer

A method for concentrating and determining phosphate in natural waters, using poly(N-isopropylacrylamide) (PNIPAAm); a thermally reversible polymer, is described. Poly(N-isopropylacrylamide) is soluble in water below 31 degrees C but shrinks abruptly on heating above 31 degrees C, becoming insoluble. With phase separation of PNIPAAm from aqueous solution at 45 degrees C, a molybdophosphate-Malachite Green aggregate (P-Mo-MG), formed by reaction of a Mo-MG reagent, obtained by mixing ammonium molybdate and Malachite Green, was incorporated in PNIPAAm and the resulting solid stuck to the walls of the reaction vessel. After discarding the supernatant solution by decantation, the P-Mo-MG aggregate was dissolved in a small volume of methylcellosolve together with PNIPAAm. The absorbance (lambda max = 627 nm) was proportional to the concentration of phosphate with an apparent molar absorptivity of 2.6 x 10(4) m2 mol-1. This method makes possible the rapid determination of trace amounts of phosphate in water using simple apparatus. The detection limit was 2 nmol dm-3 of phosphate. The method was successfully applied to the determination of phosphate in natural water samples such as tap water, mineral water and rain water.

A longitudinal study of growth and development of stature among prenatally exposed atomic bomb survivors

Growth retardation due to exposure to the atomic bomb has been evaluated using repeated measurements of stature from 10 to 18 years of age. A highly significant growth retardation due to the DS86 uterine dose was observed in all trimesters combined and in the first and second trimesters of pregnancy. In the first trimester, all parameter estimates based on a linear (L) or linear-quadratic (L-Q) dose-response relationship were negative in relation to the DS86 uterine dose. The positive dose estimate in the second trimester is small and close to the control level. Statistically significant difference was determined by a multivariate test statistic examining whether or not a set of two- or three-parameter estimates including a constant term related to an L or L-Q dose-response relationship was different from zero. A radiation-related growth retardation was demonstrable as a longitudinal result of the repeated measurements of stature. The dose effect in the third trimester was not significant under either the L or the L-Q model. The relationship between birth weights and repeated measurements of stature in adolescence is discussed based on the results obtained by a growth curve analysis.

Immunopathological stain of lipoarabinomannan-B (LAM-B) for diagnosis of leprosy

We developed an immunopathological staining of LAM-B antigen in formalin-fixed paraffin-embedded tissues, and compared it with, PGL-I immunostaining, Fite Faraco's stain and periodic acid carbol pararosaniline (PACPR) stain. Out of the total 28 leprosy cases, 27 were positive to LAM-B immunostaining while 23 were positive to PGL-I stain. Fite's stain was positive in 21 cases while PACPR stain was positive in 24 cases. In scrofuloderma, LAM-B antigen was observed only in the granuloma while no other positive findings were noted with other stains. Normal skin did not give any positive findings with any of the stains. Other dermatoses showed no positive findings to any of the stains tested. LAM-B staining was observed in the nerve even in the absence of bacilli in leprosy tissues. Presence of LAM-B in the cutaneous nerves is helpful in discriminating leprosy from other mycobacterioses. Considering the high sensitivity of LAM-B and the predilection of M. leprae for the nerves, we concluded that LAM-B staining can be a useful new tool in the prompt diagnosis of leprosy, especially in suspected or early cases.

Demonstration of PGL-I & LAM-B antigens in paraffin sections of leprosy skin lesions

An investigation on the demonstration of PGL-I and LAM-B antigens in thirty-four paraffin embedded skin biopsies taken from leprosy patients who covered the whole spectrum of the disease and in four control specimens was carried out. Neither the PGL-I antigen nor the LAM-B antigen was demonstrated in the normal skin specimens that were used as negative control; and only the LAM-B antigen appeared in the tuberculosis specimens in which the PGL-I antigen was negative. The PGL-I antigen was demonstrated on thirty-three leprosy samples except one TT sample and the LAM-B antigen, on all samples by immunochemical staining technique. The antigens were identified as intracytoplasmic bacillary staining, in solitary, granular as well as debris patterns; and as soluble antigenic staining, in vacuolar or amorphous pattern. In LL and BL cases, the antigens were detected predominantly from macrophages and peripheral nerves in all five staining patterns; in BB cases, from macrophages mostly in the granular as well as debris patterns, from the nerves in the vacuolar pattern; while in TT and the majority of BT cases, they were mainly from nerve remnants inside the granuloma in the vacuolar or amorphous staining pattern. In addition, it is interesting to note that the immunochemical staining was able to differentiate the foamy change from the hydropic degeneration. We also found that the antigens distributed in arrector pili muscles and the walls of muscular vessels were obviously related to the unmyelinated nerve fibers innervating the smooth muscle cells.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of traumatic right diaphragmatic hernia diagnosed by pleurography]

The diagnosis of traumatic diaphragmatic hernia is relatively easy on the left side, but is often difficult on the right, partly because the herniated organ is usually the liver. Recently, we experienced a relatively rare case of traumatic right diaphragmatic hernia and found that pleurography was useful for its diagnosis. This case is reported here together with some discussion of the literature.

[Modification of Harada's method for rapid staining of mycobacteria]

Harada employed periodic acid-carbol pararosaniline and periodic acid-methenamine silver stain for demonstrating chromophobic bacilli which do not get stained with conventional carbol fuchsin or counter stain. This staining method takes considerable time for complete oxidation with periodic acid. We have succeeded in reducing the oxidation time by using hydrogen peroxide treatment prior to periodic acid and with the use of acidified sodium hydrogen sulfite treatment before carbol pararosaniline stain. We also found that in methenamine silver stain, combined use of semicarbazide and microwave treatment can shorten the whole staining time up to four hours without losing ito sensitivity.

[Quantitative non-radioactive in situ hybridization for measurement of specific mRNA using image analyzer]

To understand cells, information on the state of gene expression in each cell is essential. We determined the copy number of c-myc mRNA in HL60 cell by first carrying out in situ hybridization using thymine-thymine dimerized anti-sense oligonucleotides probes to c-myc mRNA and the hybridized thymine dimers were localized by the immunoperoxidase method. The density of each cell was measured by an image analyzer and converted to the mRNA copy number in each cell, using dot blot hybridization results, as a reference standard. It was found that the numbers of c-myc mRNA copies varied 0-4,000 when expressed at the unit of cell.

[Flow cytometric analysis of cellular DNA content in epithelial ovarian cancer]

Tumor DNA content (ploidy) was determined by flow-cytometry (FCM) on tissue from 32 epithelial ovarian cancer patients. Staining for DNA analysis was achieved with Propidium Iodide. Peripheral blood lymphocytes were used as reference diploid cell population. Of the 32 patients, 26 (81.3%) had tumors which were aneuploid, whereas 6 (18.7%) were diploid. DNA aneuploid cell lines were found in 100% of serous adenocarcinoma, in 57% of mucinous adenocarcinoma, in 67% of endometrial adenocarcinoma, in 88% of clear cell carcinoma and in 75% of undifferentiated carcinoma. The DNA ploidy abnormalities differed in each histologic characteristic of epithelial ovarian cancer.

Detection of Mycobacterium leprae and the potential for monitoring antileprosy drug therapy directly from skin biopsies by PCR

An improved protocol for PCR analysis of Mycobacterium leprae-infected tissues, based on enzymatic lysis, has been developed and used to demonstrate the feasibility of using PCR for detecting M. leprae in routine skin biopsies taken from leprosy patients throughout the clinical spectrum. Of 92 multibacillary patients tested, 99% were PCR-positive using gel electrophoresis or DNA hybridization to detect the amplified product. Similar analysis of paucibacillary patients, in which only one of 27 biopsies had demonstrable AFB microscopically, gave a positivity rate of 74%. No PCR signals were demonstrated from skin biopsies from seven patients with non-leprosy dermatoses and one AIDS patient with a disseminated atypical mycobacteriosis. Evaluation of leprosy patients with antileprosy drug therapy prior to biopsy demonstrated that PCR signals were either greatly diminished or absent after 2 months of continuous antibiotic therapy. PCR was also able to detect the presence of M. leprae in tissues of patients receiving antibacterial therapy when patients were suspected of harbouring drug-resistant M. leprae.