Clusters of Pneumocystis carinii pneumonia: analysis of person-to-person transmission by genotyping

Genotyping at the internal transcribed spacer (ITS) regions of the nuclear rRNA operon was performed on isolates of P. carinii sp. f. hominis from three clusters of P. carinii pneumonia among eight patients with haematological malignancies and six with HIV infection. Nine different ITS sequence types of P. carinii sp. f. hominis were identified in the samples from the patients with haematological malignancies, suggesting that this cluster of cases of P. carinii pneumonia was unlikely to have resulted from nosocomial transmission. A common ITS sequence type was observed in two of the patients with haematological malignancies who shared a hospital room, and also in two of the patients with HIV infection who had prolonged close contact on the ward. In contrast, different ITS sequence types were detected in samples from an HIV-infected homosexual couple who shared the same household. These data suggest that person-to-person transmission of P. carinii sp. f. hominis may occur from infected to susceptible immunosuppressed patients with close contact within hospital environments. However direct transmission between patients did not account for the majority of cases within the clusters, suggesting that person-to-person transmission of P. carinii sp. f. hominis infection may be a relatively infrequent event and does not constitute the major route of transmission in man.

PCR for detecting Pneumocystis carinii in clinical or environmental samples

Since Pneumocystis carinii cannot be cultured in vitro, the introduction of polymerase chain reaction (PCR) has been an enormous advantage for research purposes. It is now possible to detect P. carinii in specimens containing low numbers of organisms where conventional detection methods using microscopic examination of histochemical stains has been insufficient. PCR has been used to detect P. carinii in bronchoalveolar lavage, induced sputum, spontaneous expectorates, oropharyngeal gargles, nasopharyngeal aspirates, serum, blood and in environmental samples. The use of PCR will enable the study of the epidemiology of P. carinii infection by detecting the organism in environmental samples, permitting molecular typing and thereby the study of the transmission of the organism. Furthermore PCR will facilitate studies on the response to therapy, studies monitoring for the emergence of drug resistant strains of P. carinii and in the diagnosis of P. carinii pneumonia in noninvasive specimens, in patients unable to undergo more invasive diagnostic procedures.

Cultured rat and purified human Pneumocystis carinii stimulate intra- but not extracellular free radical production in human neutrophils

The production of free radicals in human neutrophils was studied in both Pneumocystis carinii derived from cultures of L2 rat lung epithelial-like cells and Pneumocystis carinii purified from human lung. Using the cytochrome C technique, which selectively measured extracellular superoxide generation, hardly any free radical production was observed after stimulation with cultured rat-derived P. carinii. A chemiluminescence technique, which separately measured intra- and extracellular free radical production, was subsequently employed to differentiate the free radical generation. It was established that 1) P. carinii stimulated intra- but not extracellular free radical production in human neutrophils, 2) opsonized cultured rat-derived P. carinii stimulated human neutrophils to a strong intracellular response of superoxide production, and 3) opsonized P. carinii, purified from human lung also stimulated human neutrophils to produce intracellular free radicals.

Diagnostic use of PCR for detection of Pneumocystis carinii in oral wash samples

There is a need to develop noninvasive methods for the diagnosis of Pneumocystis carinii pneumonia in patients unable to undergo bronchoscopy or induction sputum. Oral wash specimens are easily obtained, and P. carinii nucleic acid can be amplified and demonstrated by PCR. In routine clinical use, easy sample processing and single-round PCR are needed to ensure rapid analysis and to reduce the risk of contamination. We developed a single-round Touchdown PCR (TD-PCR) protocol with the ability to detect PCR inhibition in the specimen. The TD-PCR was evaluated in a routine diagnostic laboratory and was compared to a previously described PCR protocol (mitochondrial RNA) run in a research laboratory. Both PCR methods amplified a sequence of the mitochondrial rRNA gene of P. carinii. Paired bronchoalveolar lavage (BAL) and oral wash specimens from 76 consecutive human immunodeficiency virus type 1-infected persons undergoing a diagnostic bronchoscopy were included. The TD-PCR procedure was quicker than the mitochondrial PCR procedure (<24 versus 48 h) and, compared to microscopy, had sensitivity, specificity, and positive and negative predictive values of 89, 94, 93, and 91%, respectively, for oral wash specimens and 100, 91, 90, and 100%, respectively, for BAL specimens. Our results suggest that oral wash specimens are a potential noninvasive method to obtain a diagnostic specimen during P. carinii pneumonia infection and that it can be applied in a routine diagnostic laboratory.

Growth hormone- and testosterone-dependent regulation of glutathione transferase subunit A5 in rat liver

The class Alpha glutathione S-transferase (GST) subunit A5 is expressed in the livers of young male and female rats. After sexual maturation, this protein is no longer detectable in the livers of male rats, but is still expressed in female rats. We have previously demonstrated that the sexually dimorphic secretion of growth hormone regulates the levels of certain class Mu GSTs in rat liver, and this study was designed to investigate the hormonal regulation of GSTA5. Control and hypophysectomized rats of both sexes were used to study the role of growth hormone in the regulation of hepatic GSTA5; and the influence of testosterone on the expression of this same subunit was investigated in intact females and castrated males. Liver cytosols were subjected to SDS/PAGE and immunoblotting using antibodies directed towards rat (r)GSTA5, and to affinity purification on glutathione-Sepharose followed by reverse-phase HPLC in order to quantify the relative levels of rGSTA1, A2, A3, A4, M1 and M2 subunits. These analyses revealed that the expression of rGSTA5 is, indeed, regulated by both growth hormone and testosterone.

Characterization of the UDP-glucuronosyltransferase isoenzyme expressed in rat ovary and its regulation by gonadotropins

Earlier studies have demonstrated that phenol UDP-glucuronosyltransferase (UGT) activity is up-regulated by pregnant mare's serum gonadotropin (PMSG) in rat ovary, but not liver. This phenomenon was investigated in more detail in the present study. Ovaries and livers of immature rats, rats synchronized with respect to their preovulatory and corpus luteal phases by treatment with PMSG, and mature rats hyperstimulated with PMSG were compared. Under all of these conditions, only one immunoreactive band of UGT, shown to be phenol UGT, was detected in the rat ovary. The effects of oestradiol, progesterone and/or human chorionic gonadotropin (hCG) on the level of phenol UGT in immature rat ovary were also examined. Partial up-regulation was caused by progesterone or oestradiol, together with hCG, whereas progesterone or oestradiol alone had no up-regulating effect. Follicle-stimulating hormone also seemed to be required for the up-regulation in ovaries enriched in corpus luteum. The present findings demonstrate that progesterone is involved in the regulation of phenol UGT in rat ovary by gonadotropins. Regulation by both progesterone and oestradiol was dependent on induction of ovulation and steroidogenesis by luteinizing hormone.

Update on Pneumocystis carinii f. sp. hominis typing based on nucleotide sequence variations in internal transcribed spacer regions of rRNA genes

Pneumocystis carinii f. sp. hominis isolates from 207 clinical specimens from nine countries were typed based on nucleotide sequence variations in the internal transcribed spacer regions I and II (ITS1 and ITS2, respectively) of rRNA genes. The number of ITS1 nucleotides has been revised from the previously reported 157 bp to 161 bp. Likewise, the number of ITS2 nucleotides has been changed from 177 to 192 bp. The number of ITS1 sequence types has increased from 2 to 15, and that of ITS2 has increased from 3 to 14. The 15 ITS1 sequence types are designated types A through O, and the 14 ITS2 types are named types a through n. A total of 59 types of P. carinii f. sp. hominis were found in this study.

Phacoemulsification and lens implantation in rabbit eyes: capsular bag versus ciliary sulcus implantation and 4.0 versus 7.0 mm capsulorhexis

PURPOSE

To compare the effects of intraocular lens (IOL) implantation in the capsular bag versus the ciliary sulcus and of a 4.0 versus 7.0 mm continuous curvilinear capsulorhexis (CCC) on postoperative inflammation and after-cataract formation.

SETTING

St. Erik's Eye Hospital, Karolinska Institute, Stockholm, Sweden.

METHODS

Trial 1 comprised 40 rabbits that had CCC, endocapsular phacoemulsification, and a poly(methyl methacrylate) IOL implanted in the capsular bag in one eye and the ciliary sulcus in the fellow eye. In Trial 2, 40 rabbits had a 4.0 mm CCC in one eye and a 7.0 mm CCC in the fellow eye followed by phacoemulsification and IOL implantation in the capsular bag. White blood cell (WBC) counts and prostaglandin E2 (PGE2) concentrations in aqueous humor were determined at 1, 3, 7(8), 28, and 56 days postoperatively. Wet mass of the dissected after-cataract was measured at day 56. In Trial 1, wet mass of the iris-ciliary body was measured at each observation.

RESULTS

In Trial 1, WBC counts at day 1 were higher with a sulcus-fixated IOL (P = .05). The median wet mass of the dissected after-cataract was 108.5 mg in eyes with a sulcus-fixated IOL and 62.5 mg in eyes with a capsule-fixated IOL (P = .01). In Trial 2, WBC counts at day 8 were significantly higher in eyes with a 7.0 mm CCC than in those with a 4.0 mm CCC (P < .05). There was no significant difference in the amount of after-cataract.

CONCLUSIONS

The results indicate that IOL implantation in the capsular bag causes less inflammation and after-cataract formation than sulcus fixation and that using a large CCC does not affect the total amount of after-cataract but may enhance the inflammatory response.

The major surface glycoprotein of Pneumocystis carinii induces release and gene expression of interleukin-8 and tumor necrosis factor alpha in monocytes

Recent studies suggest that interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-alpha) may play a central role in host defense and pathogenesis during Pneumocystis carinii pneumonia. In order to investigate whether the major surface antigen (MSG) of human P. carinii is capable of eliciting the release of IL-8 and TNF-alpha, human monocytes were cultured in the presence of purified MSG. MSG-stimulated cells released significant amounts of IL-8 within 4 h, and at 20 h, cells stimulated with MSG released 45.5 +/- 9.3 ng of IL-8/ml versus 3.7 +/- 1.1 ng/ml for control cultures (P = 0.01). In a similar fashion, MSG elicited release of TNF-alpha. Initial increases were also seen at 4 h, and at 20 h, TNF-alpha levels reached 6.4 +/- 1.1 ng/ml, compared to 0.08 +/- 0.01 ng/ml for control cultures (P < 0.01). A concentration-dependent increase in IL-8 and TNF-alpha secretion was observed at 20 h with 0.2 to 5 microg of MSG/ml (P < 0.01). Secretion of IL-8 and TNF-alpha from MSG-stimulated monocytes at 20 h was inhibited by 60 and 86%, respectively, after coincubation with soluble yeast mannan (P = 0.01). With an RNase protection assay, increases in steady-state mRNA levels for IL-8 and TNF-alpha were detectable at 4 h. These data show that recognition of MSG by monocytes involves a mannose-mediated mechanism and results in the release of the proinflammatory cytokines IL-8 and TNF-alpha.

Linell classification of breast cancer morphology compared to histologic grading, S-phase fraction and DNA-ploidy

One hundred and fifty-eight histologically verified mammary carcinomas with known mammographic doubling time (DT) were studied with special emphasis on a morphologic classification proposed by Linell et al. [8, 12, 14, 15]. The hypothesis that Linell classification of ductal carcinomas into comedo, tubuloductal and tubular carcinomas is easy to perform with small inter-observer variations, was not fully confirmed. The Linell classification was found to correlate well with conventional WHO malignancy grading, S-phase fraction and DNA-ploidy. The Linell classification also correlated to surgical stage, lymph node status and DT, but not at all to tumour size. Using distant disease-free survival as an endpoint, the Linell classification gave prognostic information comparable to conventional histologic grading, seeming to be a simple, cheap and reliable method well worth trying on a larger scale.

Inflammatory response after endocapsular phacoemulsification or conventional extracapsular lens extraction in the rabbit eye

PURPOSE

We compared the inflammatory response after phacoemulsification and conventional extracapsular lens extraction in New Zealand albino rabbits.

METHODS

One eye was selected at random and phacoemulsification was performed. Extracapsular lens extraction was done in the fellow eye. In both eyes a polymethylmetacrylate intraocular lens was implanted into the capsular bag and the wound was sutured with a 9-0 polypropylene continuous suture. The levels of prostaglandin E2 in aqueous humour and wet mass of the iris-ciliary bodies were measured at day 1. The number of white blood cells and protein levels in the aqueous humour were measured at day 1, 3, 7, 14 and 30. Corneal thickness was estimated with pachymetry.

RESULTS

Prostaglandin E2 levels and wet masses of iris-ciliary bodies were significantly higher after extracapsular lens extraction, which also induced significantly higher white blood cells counts at day 1 and 3 and higher protein levels at day 7. Extracapsular lens extraction caused more corneal edema at day 3, 7 and 14.

CONCLUSION

The results suggest that phacoemulsification induced less surgical trauma with less breakdown of the blood-aqueous barrier.

Intraocular lens thickness and ocular growth in newborn rabbits

PURPOSE

To examine ocular growth in newborn rabbits with a thick or a thin silicone intraocular lens implanted.

METHODS

Bilateral lensectomy was performed in twelve 23-day-old rabbits. All eyes were implanted with a silicone intraocular lens (IOL) with polypropylene haptics (Allergan Medical Optics SI 26 NB). In each rabbit, one eye was selected at random and a +12 diopter IOL with a centre thickness of 1.10 mm was implanted in the capsular bag. In the other eye a +24 diopter IOL with a centre thickness of 1.83 mm was implanted. Axial length, corneal diameter, corneal thickness and intraocular pressure were measured in all eyes preoperatively, and then 1, 2 and 3 months after surgery. The wet mass of the after-cataract was measured 3 months after surgery.

RESULTS

Both the axial length and the corneal diameter were significantly increased in eyes implanted with the thicker silicone IOL. No significant difference in corneal thickness or intraocular pressure was found between the eyes. No correlation was found between the IOL-thickness and the wet mass of the after-cataract.

CONCLUSION

The results suggest that in the young rabbit eye the thickness of an implanted IOL influences eye growth.

Transmission of Pneumocystis carinii from patients to hospital staff

BACKGROUND

An extrahuman reservoir of human pathogenic Pneumocystis carinii remains unknown. Host to host transmission has been described in animal studies and in cluster cases among immunodeficient patients. P carinii DNA has recently been detected in air filters from inpatient and outpatient rooms in departments of infectious diseases managing patients with P carinii pneumonia (PCP), suggesting the airborne route of transmission. Exposure of staff to P carinii may occur in hospital departments treating patients with PCP.

METHODS

Exposure to P carinii was detected by serological responses to human P carinii by ELISA, Western blotting, and indirect immunofluorescence in 64 hospital staff with and 79 staff without exposure to patients with PCP from Denmark and Sweden. DNA amplification of oropharyngeal washings was performed on 20 Danish staff with and 20 staff without exposure to patients with PCP.

RESULTS

There was no significant difference in the frequency or level of antibodies to P carinii between staff exposed and those unexposed to patients with PCP. None of the hospital staff had detectable P carinii DNA in oropharyngeal washings.

CONCLUSIONS

There is no difference in antibodies and no detectable P carinii DNA in oropharyngeal washings, which suggests that immunocompetent staff treating patients with PCP are not a potentially infectious source of P carinii for immunocompromised patients.

Ocular growth in newborn rabbit eyes implanted with a poly(methyl methacrylate) or silicone intraocular lens

PURPOSE

To examine eye growth in lensectomized infant rabbits implanted with a poly(methyl methacrylate) (PMMA) or a silicone intraocular lens (IOL).

SETTING

S:t Eriks Eye Hospital, Karolinska Institute, Stockholm, Sweden.

METHODS

Two groups of 3-week-old rabbits were used. In Group 1 (n = 13), lensectomy was performed in both eyes. In one randomly selected eye, a +30 diopter (D) heparin-surface-modified (HSM) PMMA IOL was implanted in the capsular bag; the other eye was left aphakic. In Group 2 (n = 10), a +21 D HSM PMMA IOL was implanted in one randomly selected eye and a +21 D silicone IOL was implanted in the other. Axial length, corneal diameter, corneal thickness, and intraocular pressure (IOP) were measured in all eye preoperatively and 1, 2, and 3 months after surgery. The wet mass of the after-cataract was measured 3 months after surgery. The ciliary body with the ciliary processes and the peripheral retina were examined histologically after formalin fixation. The two IOL types were compressed to 7.0 MM, corresponding to the diameter of the 3-week-old rabbit lens.

RESULTS

In Group 1, the axial length was significantly decreased in the eye with an HSM PMMA IOL compared with the fellow aphakic eye (P < .01, two-way analysis of variance [ANOVA]). No significant difference in corneal diameter, corneal thickness, or IOP was found between the eyes. The wet mass of the dissected after-cataract was significantly less in the eye implanted with an IOL. Two animals had an elevated IOP with secondary glaucoma in their aphakic eye and were excluded from the study. In Group 2, axial length in eyes with the HSM PMMA IOL was less than in the eyes with the silicone IOL (P < .25, two-way ANOVA). No difference in corneal diameter, corneal thickness, or IOP was found. The amount of after-cataract was not altered. Histologically, the eyes with the HSM PMMA IOL showed retinal degeneration, neovascularization of the ciliary body accompanied by a large number of inflammatory cells, and tumid ciliary processes. The eyes with the silicone IOL showed only minor changes. The aphakic eyes presented even less histological change. The compression test demonstrated that three time the compression force was needed to squeeze the HSM PMMA lens than the silicone IOL.

CONCLUSION

The results suggest that in the young rabbit eye, implanting a regular size HSM PMMA IOL destroys intraocular tissues and reduces eye growth significantly. Replacing the PMMA IOL with a silicone IOL improves the ocular growth.

Inflammatory response in the rabbit after phacoemulsification and intraocular lens implantation using a 5.2 or 11.0 mm incision

PURPOSE

To study the effect of two incision sizes, 5.2 and 11.0 mm, on the inflammatory response in rabbit eyes after lens extraction with phacoemulsification.

SETTING

S:t Erik's Eye Hospital, Stockholm, and Pharmacia, Uppsala, Sweden.

METHODS

Bilateral endocapsular phacoemulsification was performed on 32 rabbits. The wound was enlarged to 5.2 mm, and a poly(methyl methacrylate) intraocular lens (IOL) was implanted in the capsular bag. In each rabbit, one eye was selected at random and the wound in that eye enlarged to 11.0 mm. In both eyes the wound was sutured with a 9-0 polypropylene continuous suture. The number of white blood cells (WBCs) and prostaglandin E2 (PGE2) in the aqueous humor were measured at days 1, 3, 7, and 28 postoperatively. Corneal thickness was also measured by pachymetry.

RESULTS

The number of WBCs at day 3 and the PGE2 levels at days 1, 3, and 7 were significantly higher in eyes with 11.0 mm incisions than in eyes with 5.2 mm incisions. One week after surgery, the corneas in the eyes with 11.0 mm incisions were significantly thicker than in those with 5.2 mm incisions.

CONCLUSION

The results indicate that incision size is an important factor in the inflammatory response following phacoemulsification and IOL implantation in the rabbit eye.

After-cataract and ocular growth in newborn rabbit eyes implanted with a capsule tension ring

PURPOSE

To examine after-cataract and eye growth in lensectomized newborn rabbits implanted with capsule tension rings of different sizes.

SETTING

S:t Eriks Eye Hospital, Karolinska Institute, Stockholm, Sweden.

METHODS

Two groups of 24-day-old rabbits were used. In Group 1 (n = 9), lensectomy was performed in both eyes. In one randomly selected eye, an open poly(methyl methacrylate) (PMMA) capsule tension ring with a 7.0 mm diameter and 0.13 mm thickness was implanted in the capsular bag. The other eye was left aphakic. In Group 2 (n = 10), an open PMMA capsule tension ring with a 10.0 mm diameter and 0.13 mm thickness was implanted in one randomly selected eye, and the other eye was left aphakic. Axial length, corneal diameter, corneal thickness, and intraocular pressure (IOP) were measured in all eyes preoperatively and 1, 2, and 3 months after surgery. The wet mass of the after-cataract was measured at 3 months. Three Group 1 eyes and four Group 2 eyes developed secondary glaucoma and were excluded from the study.

RESULTS

Axial growth did not differ significantly between the eyes implanted with the 7.0 mm ring and the aphakic eyes (mean difference 0.01 mm; F3;15 = 0.02; P > .25). Corneal diameter also did not differ (two-way analysis of variance [ANOVA]). Axial length growth was less in the eyes implanted with the 10.0 mm ring than in the aphakic eyes (mean difference 1.05 mm; F3;15 = 2.06; P < .25). The average decrease in corneal diameter growth was 1.0 mm in the implanted eyes. Growth in the eyes with the 10.0 mm ring was significantly less than in the eyes with the 7.0 mm ring (P = .05, Wilcoxon rank-sum test). Corneal thickness and IOP did not differ significantly between eyes (F3;15 = 0.6; P > .25; two-way ANOVA). Amount of after-cataract did not differ significantly between the aphakic eyes and the eyes implanted with the 7.0 mm ring. It was significantly less in the eyes with the 10.0 mm ring than in those with the 7.0 mm ring (Wilcoxon signed-rank test) and in the aphakic eyes (P < .025, Wilcoxon rank-sum test).

CONCLUSION

In the young rabbit eye, a 10.0 mm capsule ring reduced the eye growth compared with both the aphakic eye and the eye implanted with a 7.0 mm ring. The 10.0 mm ring also inhibited the production of after-cataract compared with the production in the aphakic eye and the eye implanted with the 7.0 mm ring.

Pneumocystis carinii from pigs and humans are antigenically distinct

The antigens of Pneumocystis carinii cysts isolated from pigs and humans were compared by the Western immunoblotting technique. Convalescent pig serum reacted with two antigens (approximately 78 kDa and 32.5 kDa) of porcine P. carinii cysts, whereas convalescent serum from humans did not react with porcine P. carinii cyst antigens. The results indicate that porcine and human P. carinii cysts are antigenically distinct.

Eye growth in the aphakic newborn rabbit

PURPOSE

To examine growth in unilaterally lensectomized newborn rabbits.

SETTING

S:t Erik Eye Hospital, Karolinska Institute, Stockholm, Sweden.

METHODS

Unilateral lensectomy was performed in 18 randomly selected 23-day-old rabbits. Corneal incision was performed in 2 other rabbits, and the aqueous humor was replaced with balanced salt solution in one eye. Axial length, corneal diameter, corneal thickness, intraocular pressure (IOP), and refraction were measured in all eyes preoperatively and 1, 2, and 3 months postoperatively. The wet mass of the after-cataract was measured 3 months after surgery.

RESULTS

The growth of the aphakic eye, as indicated by axial length and corneal diameter, was significantly less than that of the control eye in 14 rabbits. No significant difference in IOP or corneal thickness was found between the lensectomy and control eyes. Four animals had elevated IOP with secondary glaucoma and were excluded from the study. No difference in eye growth was found between the two eyes when no lensectomy was performed. Refraction in the unoperated eye showed a myopic shift. After lensectomy, the operated eye became hyperopic with a myopic shift 3 months after surgery. No correlation was found between eye growth and the wet mass of the after-cataract.

CONCLUSIONS

Our results suggest that removal of the rabbit crystalline lens at an early age reduces eye growth.