DNA replication regulation protein Mcm7 as a marker of proliferation in prostate cancer

BACKGROUND

Recent studies have shown that minichromosome maintenance (MCM) proteins (Mcm2-7) may be useful proliferation markers in dysplasia and cancer in various tissues.

AIMS

To investigate the use of Mcm7 as a proliferation marker in 79 lymph node negative prostate cancers and compare it with Ki-67, a commonly used cell proliferation marker.

METHODS

The percentage of proliferating cells (proliferation index; PI) was calculated for basal and luminal epithelial cells in benign prostate tissue, prostatic intraepithelial neoplasia (PIN), and epithelial cells in adenocarcinoma. The PI for each biomarker was correlated with the preoperative prostate specific antigen concentration, the Gleason score, surgical resection margin status, and the AJCC pT stage for each patient.

RESULTS

The mean PIs for Ki-67 and Mcm7 were: benign luminal epithelium 0.7 and 1.2 and benign basal epithelium 0.8 and 8.2; PIN non-basal epithelium 4.9 and 10.6 and PIN basal epithelium 0.7 and 3.1; adenocarcinoma 9.8 and 22.7, respectively. Mcm7 had a significantly higher mean PI (p<0.0001) than Ki-67 for all cell categories except benign luminal epithelial cells. Mcm7 was a better discriminatory marker of proliferation between benign epithelium, PIN, and invasive adenocarcinoma (p<0.0001) than Ki-67. The drop in Mcm7 mean basal cell PI from benign epithelium to PIN epithelium was significantly larger than for Ki-67 (p<0.0001). Mcm7 had a significantly higher PI than Ki-67 at each risk level.

CONCLUSION

Mcm7 may be a useful proliferation marker in prostatic neoplasia and warrants further evaluation as a complementary tool in the diagnosis of PIN and prostate carcinoma.

Collagenous gastritis: a long-term follow-up with the development of endocrine cell hyperplasia, intestinal metaplasia, and epithelial changes indeterminate for dysplasia

This report reviews the literature pertaining to collagenous gastritis and describes the clinicopathologic evolution of this disease in a patient during a 12-year period. We examined 109 biopsy specimens of gastric mucosa from 19 different endoscopic procedures for the severity and distribution of collagenous gastritis in a single patient. Assessments were undertaken for the presence of endocrine and gastrin cell hyperplasias and dysplastic epithelial changes. Relative to biopsy specimens from age- and sex-matched control subjects, the patient's biopsy specimens showed a significantly lower number of antral gastrin cells, along with a significant corpus endocrine cell hyperplasia, suggesting an increased risk of endocrine neoplasia. Gastric corpus biopsy specimens revealed an active, chronic gastritis, subepithelial collagen deposition, smooth muscle hyperplasia, and mild to moderate glandular atrophy. Additional findings of intestinal metaplasia and reactive epithelial changes indeterminate for dysplasia raise concerns about the potential for adenocarcinoma.

The characteristic appearance of non-alcoholic duct destructive chronic pancreatitis: a report of 2 cases

We report 2 patients with an unusual form of chronic pancreatitis, both of whom were treated for clinical suspicion of pancreatic malignancy. The surgical specimens revealed a dense lymphoplasmacytic infiltration of the main and interlobular branches of the pancreatic duct, causing sclerosis of the duct wall, diffuse irregular lumenal narrowing, extensive parenchymal fibrosis, and organ enlargement. Neither case showed calcifications, fat necrosis, or cyst formation, features usually seen in alcoholic pancreatitis, nor was there any evidence of neoplasia. One patient had an unusual form of acalculous cholecystitis, but without cystic duct inflammation or fibrosis. Both patients recovered well from the surgical procedure and have not had any complications or relapse of their symptoms. To the best of our knowledge, these cases are representative of the recently described non-alcoholic duct destructive chronic pancreatitis, which is thought to be immune-mediated.

Cystic hamartoma of the renal pelvis: a rare pathologic entity

We report a case of a rare cystic renal tumor previously termed cystic hamartoma of the renal pelvis. A 53-year-old woman presented to her gynecologist with menometorrhagia. She subsequently had a computed tomographic scan that demonstrated an incidental cystic mass in the lower pole of the left kidney. Histologically, the tumor was composed of a mixture of benign mesenchymal and epithelial components. The stroma consisted of spindle cells with monomorphic nuclei and abundant eosinophilic cytoplasm that resembled smooth muscle and that reacted positively with antibodies to alpha-smooth muscle actin, desmin, and vimentin. The epithelial component was composed mostly of cysts lined by cuboidal-to-columnar epithelium. Focal dilated cysts were lined by epithelium with oncocytic features. We think that this entity is distinct from other renal tumors, including mesoblastic nephroma, cystic nephroma, or a cystic, partially differentiated nephroblastoma, and that it is best classified as a cystic hamartoma of the renal pelvis.

Utility of hepatic iron index in American patients with hereditary hemochromatosis: a multicenter study

BACKGROUND & AIMS

A hepatic iron index (hepatic iron concentration divided by age) of more than 1.9 has been proposed as useful to identify patients with homozygous hereditary hemochromatosis (HHC). There are limited data on the diagnostic use of the hepatic iron index in patients with HHC in the United States. This study evaluated the hepatic iron index in the diagnosis of HHC in a multicenter U.S. study.

METHODS

Hepatic iron concentration was measured in 509 patients undergoing liver biopsy. The diagnosis of HHC was made using clinical, biochemical, and histopathologic criteria.

RESULTS

Fifty-five patients met criteria for HHC; hepatic iron index was > 1.9 in 51 of 55 (93%) patients with HHC but in none of 454 patients with other liver diseases; hepatic iron concentration was > 71 mumol/g dry weight in 54 of 55 patients with HHC but only 1 of the other 454 patients.

CONCLUSIONS

A hepatic iron index of > or = 1.9 can identify most U.S. patients with HHC but is < or = 1.9 in 7%. A "threshold" hepatic iron concentration of 71 mumol/g can almost always distinguish patients with HHC from patients with other liver diseases and may be a useful adjunct to the hepatic iron index in the diagnosis of HHC in the diverse U.S. population.

Diagnostic accuracy of a rural live video telepathology system

Accuracy of diagnoses rendered using a live video telepathology network was assessed for permanent sections of surgical pathology specimens. To determine accuracy, telepathology diagnoses were compared with those obtained by directly viewing the glass slide using a standard microscope. A total of 294 cases were read via both telepathology and glass slide by attending pathologists at a tertiary care medical center. Overall accuracy was defined as exact concordance between diagnoses. Clinically insignificant differences in diagnoses were excluded to determine clinically significant accuracy. For the 285 cases with complete data, the overall accuracy for telepathology was 0.912 (95% confidence interval [CI], 0.872-0.941), whereas the overall accuracy for glass slide readings was 0.968 (95% CI, 0.939-0.985). This difference is statistically significant (p = 0.009). When focusing on clinically significant discrepancies, where the difference in diagnosis might affect therapeutic decisions, the video accuracy was only slightly less than the glass slide accuracy (0.965 [95% CI, 0.934-0.982] vs. 0.982 [95% CI, 0.957-0.994], respectively), but this difference is not statistically significant (p = 0.302). Most of the cases with clinically significant differences involved lesions with inherently high interobserver variation. Certainty of diagnosis did not differ between video and glass slide readings (p = 0.911), but there was an association between certainty of diagnosis and diagnostic accuracy for video (p = 0.003 for clinically significant accuracies). Based on these findings, we recommend when using this telepathology system that only preliminary diagnoses should be given in the following situations: for diagnostic areas with known high interobserver variability; when the consultant has any degree of uncertainty about the presence or absence of the lesion in question; and when there is insufficient experience using telepathology as a diagnostic medium.

The pathologist's role in the use of human tissues in research--legal, ethical, and other issues

Because of their central role in examining and storing samples of human tissues obtained for diagnosis or therapy of diseases, pathologists frequently are involved in providing human tissues for a wide range of research. This is an important role for the pathologist that leads to increased understanding of disease, to potential methods of prevention, and to improved therapy. Recent conferences concerning uses of human tissues in research have indicated that there is confusion with respect to legal issues and requirements of pathologists who are involved in research with human tissues. This paper discusses current federal regulations concerning the use of human tissues and medical information in research as specified in Title 45, Part 46 of the Code of Federal Regulations (45 CFR 46) "Protection of Human Subjects." The authors also recommend approaches that pathologists can utilize to ensure that they are meeting all federal regulations with respect to the use of human tissues in research.

Development of the human fetal testis

We describe the histological features of the fetal testis, utilizing 68 fetuses ranging in gestational age from 10 to 41 weeks. During fetal life, the tunica albuginea progressively increases in thickness, and between 29 and 32 weeks it develops two layers. Beyond 25 to 28 weeks, septa are invariably present. Tubules begin as straight structures and become maximally coiled by 30 weeks. Tubular diameter reaches its maximum by 16 weeks and remains constant throughout the rest of gestation. Germ cell and Sertoli cell numbers per tubular diameter have a wide range, but the median number for each cell type remains constant after 13 to 16 weeks. Leydig cells are most numerous between 17 and 19 weeks and decline thereafter. They are infrequent but still present at term. Interstitial lipochrome pigment accumulates during the latter half of gestation and may represent breakdown products from Leydig cell degeneration.

Intratubular germ cell neoplasia (ITGCN) with p53 and PCNA expression and adjacent mature teratoma in an infant testis. An immunohistochemical and morphologic study with a review of the literature

Intratubular germ cell neoplasia (ITGCN) and mature teratoma of the testis are uncommon findings in children. We report a case of a 3-year-old boy with both ITGCN and mature teratoma--a unique finding in our experience. Immunohistochemical markers, including placental alkaline phosphatase (PLAP), 43-9F, p53, and proliferating cell nuclear antigen (PCNA), as well as the periodic acid-Schiff (PAS) stain, were applied to the ITGCN. PLAP and 43-9F were not detected, whereas p53 and PCNA nuclear expression was detected in approximately 5% of atypical germ cells. Abundant clumped intracytoplasmic glycogen deposits were identified within atypical germ cells. Our findings indicate that both PCNA and p53, in addition to a PAS stain, may be useful markers in detecting malignant intratubular germ cells.

Localization of anti-Leu-M1 (CD15) binding sites in Hodgkin's disease by immunoelectron microscopic examination

Anti-Leu-M1 (CD15) is a monoclonal antibody used in surgical pathology to diagnoses Hodgkin's disease. By light microscopic immunohistochemistry, anti-Leu-M1 reacts with Reed-Sternberg cells and their variants, notably lacunar cells in nodular sclerosing Hodgkin's disease, as well as granulocytes in Hodgkin's disease. The immunostaining of Reed-Sternberg cells has been characteristically described as a diffuse cytoplasmic pattern with a prominent perinuclear globular component. In addition, irregular plasma membrane reactivity has been observed. To define the intracellular localization of Leu-M1 precisely, the authors performed postembedding immunoelectron microscopy with the protein A-gold technique on sections embedded in Lowicryl K4M from a patient with nodular-sclerosing-type Hodgkin's disease. At the electron microscopic level, gold particle staining indicative of Leu-M1 binding was found within cytoplasmic granules and the Golgi apparatus, as well as focally at the plasma membrane. The cytoplasmic granules were located in a perinuclear region and in the cell periphery. Although the morphology of the granules was suggested of lysosomal structures, immunolabel was not detected on serial sections of these granules with three different antibodies directed against lysosomal antigens.

Ultrastructural study of a pituitary adenoma (prolactinoma) within the clivus bone using immunoelectron microscopy

In a case of a pituitary adenoma in the clivus bone in a 71-year-old man, ultrastructural investigation using conventional aldehyde-fixed, epoxy-embedded tissue revealed the tumor to be composed of cells with euchromatic nuclei, dense nucleoli, abundant rough endoplasmic reticulum, spherical secretory granules, and granule extrusion at the lateral cell surface, all of which suggest a prolactin-producing adenoma. Using a protein A-gold immunolabeling technique on snap-frozen tissue subsequently fixed in a mild fixative and embedded in a hydrophilic resin, the presence of prolactin immunoreactivity within secretory granules at the ultrastructural level was demonstrated. This case represented the first use of protein A-gold immunolabeling at the electron microscopic level for diagnostic purposes at our institution and exemplifies the value of this technique when the need for diagnostic immunoelectron microscopy is not anticipated. Because this tumor arose in an unusual location, ultrastructural study, including immunoelectron microscopy, not only confirmed the light microscopic diagnosis of pituitary adenoma, but further allowed subclassification of the tumor.

Diagnostic immunoelectron microscopy in surgical pathology: assessment of various tissue fixation and processing protocols

We have investigated various tissue fixation and embedding protocols in an effort to allow expanded use of immunoelectron microscopy in diagnostic surgical pathology. A sample of normal human small bowel mucosa was processed using seven different methods for subsequent postembedding localization of chromogranin A. In addition, several archival cases of neuroendocrine tumors previously fixed and routinely embedded for electron microscopy, stored in formalin, or snap-frozen were retrieved and variously processed for chromogranin A localization at the ultrastructural level. Precise localization of chromogranin A in dense core granules was achieved with protein A-gold on sections from all of the processing methods. The methods included retrieval into mild fixative of previously formalin-fixed or snap-frozen tissues followed by embedding in Lowicryl K4M (Polysciences Ltd., Eppelheim, Germany). Thus, tissue processed without foresight of the need for immunoelectron microscopic localization can be successfully used. Since embedding of tissues in Lowicryl K4M has been shown to preserve a variety of antigens, it may prove to be a superior resin for use in diagnostic immunoelectron microscopy.

HMB-45 antibody demonstrates melanosome specificity by immunoelectron microscopy

The intracellular localization of antigenic sites recognized by the monoclonal antibody HMB-45 was investigated in melanomas of the choroid and skin by postembedding immunoelectron microscopy. Antigenic sites were detected by a three-step procedure, consisting of incubating sections with the monoclonal HMB-45 antibody (protein G affinity-purified ascites from Enzo Diagnostics Inc or tissue culture supernatant from Dako Corp), followed by incubation with an affinity-purified rabbit anti-mouse IgG and finally with protein A-gold complex. Gold particles, indicative of HMB-45 immunoreactivity, were restricted to melanosomes in the malignant melanocytes. Early stages in melanosome formation (stages I through III) were most intensely stained, while late-stage melanosomes (stage IV) were only sparsely labeled or not stained at all. Melanophages adjacent to a cutaneous melanoma showed intense immunoreactivity in the cytoplasm and especially over electron-dense portions of lysosomes with the HMB-45 antibody from Enzo. In marked contrast, only very sparse labeling was detected over melanophages using a similar concentration of the HMB-45 antibody from Dako. Subsequently, when the Enzo antibody was diluted 40 times above the recommended working dilution, most of the melanophage staining disappeared, while melanocyte-specific staining was maintained. Immunolabeling of melanosomes with HMB-45 was drastically reduced or absent following section pretreatment with neuraminidase, confirming an earlier report that the HMB-45 antigen is partially composed of sialic acid. Our immunoelectron microscopic results show that HMB-45 antibody specifically stains melanosomes, rather than diffuse cytoplasmic antigen, as described by light microscopic immunohistochemical analysis, thus explaining its specificity for melanocytes. In addition, the elimination of HMB-45 immunoreactivity by neuraminidase pretreatment supports the idea that sialylation of antigen is crucial to HMB-45 binding, and suggests that the absence of staining in normal adult melanocytes, dermal nevi, and other melanocytic lesions may be a result of differential sialylation.

Orbital paraganglioma: case report and review of the literature

Paragangliomas of the orbit are extremely rare. A case of an orbital paraganglioma, including the first magnetic resonance imaging description of this tumour is described here. The patient underwent surgery with gross total removal of the tumour and relief of his initial chief complaint of visual blurring. The differential diagnosis and therapeutic options for the management of this tumour are discussed.

Error in histologic dating of secretory endometrium: variance component analysis

OBJECTIVE

To characterize the extent and sources of imprecision in histologic dating of the endometrial biopsy.

DESIGN

Duplicate endometrial biopsies from 25 women were dated by five evaluators on two separate occasions to evaluate the overall precision of the measure. Using variance component analysis, estimates of intrauterine, intraevaluator, and interevaluator variability were determined.

SETTING

Samples were obtained during outpatient fertility testing. Evaluators were colleagues at the same institution.

PATIENTS, PARTICIPANTS

Women presenting with infertility undergoing routine evaluation.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Variability in histologic dating of the endometrium.

RESULTS

Inconsistencies between evaluators accounted for 65% of the observed variability, whereas 27% was because of inconsistencies in duplicate readings by the same evaluator. Regional differences in the uterus accounted for only 8% of the total variability.

CONCLUSIONS

The overall error from these sources have the potential to result in a substantial false-positive rate for diagnosis of luteal phase defect.

Adenocarcinoma of the uterine cervix of small intestinal type containing numerous Paneth cells

A case of invasive adenocarcinoma of the uterine cervix with small intestinal differentiation to include numerous Paneth cells is presented. The light microscopic findings are confirmed by immunohistochemical and electron microscopic study. To our knowledge, this is only the second reported case of small intestinal cervical adenocarcinoma that contained Paneth cells and the first with ultrastructural and immunohistochemical confirmation. A small focus of in situ adenocarcinoma with similar features is seen adjacent to the invasive area.

The adolescent varicocele. A histopathologic study of 13 testicular biopsies

Testicular varicocele, the most common cause of male infertility, frequently presents in early adolescence. To determine whether testicular damage occurs early in the natural history of varicocele, testicular biopsy specimens from 13 patients, 13 to 18 years of age (mean age, 15.5 years), were studied. The biopsies were compared with testicular tissue from six normal control subjects 15 to 28 years of age (mean age, 23.2 years). Nine of the patients with varicoceles (69.2%) demonstrated some degree of tubular sclerosis. Ultrastructural study demonstrated that the tubular sclerosis was due to collagen deposition by fibromyocytes in the peritubular sheath. Premature germ cell sloughing was present in greater than 50% of tubules examined in all but one biopsy. Six patients (46%) demonstrated small vessel sclerosis. Quantitation of the germinal epithelium revealed that the mean germ cell/Sertoli cell ratio and the percentage of germ cells present as late stage forms (secondary spermatocytes, spermatids and spermatozoa) were significantly reduced in the varicocele group. The testes of two patients exhibited severe hypospermatogenesis approaching germ cell aplasia. None of these changes were seen in the control group. The authors conclude that pathologic changes in the testes of patients with varicoceles are found at or soon after puberty. The histopathologic features include peritubular sclerosis, small vessel sclerosis, premature germ cell sloughing, and variable degrees of hypospermatogenesis.

Histology of the normal testis

The gross and microscopic features of the normal adult, prepubertal, and aging testis are described. Qualitative and quantitative parameters of spermatogenic activity are presented in practical terms. Emphasis is placed on these findings, which are important to the pathologist in interpretation of diagnostic biopsy specimens other than neoplasms.

Juvenile polyp with intramucosal carcinoma

Intramucosal carcinoma arising in an otherwise typical juvenile polyp is reported. Adenomatous change and carcinoma in situ have been previously documented in patients with the multiple juvenile polyposis syndrome. The syndrome was not present in this case. Although rare, juvenile polyps (both in solitary and multiple forms) are a potential site of malignant change.

Reversible valproate fulminant hepatic failure

Valproate fulminant hepatotoxicity, usually fatal, is believed to be idiosyncratic and metabolic without an immunologic basis. There are no previous reports of a hypersensitivity reaction among numerous cases of fatal valproate fulminant hepatitis. Little is known about the electron microscopical features of valproate hepatitis. We report a case of reversible fulminant hepatitis attributable to valproate with clinical and histological characteristics of a hypersensitivity reaction. Electron microscopical findings included microvesicular steatosis with normal-appearing mitochondria.

CAP survey of parathyroid hormone assays

Parathyroid hormone (PTH) analysis was recently added to the College of American Pathologists ligand assay survey. Synthetic whole-molecule PTH was used as the test hormone. This material was found to be stable in lyophilized serum for at least 10.7 days at 35 degrees C and 3.9 days at 45 degrees C. The survey results showed wide ranges of answers yielding within-assay coefficients of variation from 12% to 93%. The median percentage of the spiked hormone that was recovered by the various assay methods ranged from 24% to 390%. Separation of the spiked and endogenous measured PTH concentrations ranged from a twofold separation to an approximate 50% overlap of results. The survey may not be a valid indicator of PTH assay efficacy since whole-molecule human PTH may not be the most clinically important form of circulating PTH; however, the survey shows that there is a large heterogeneity in commercial PTH assays.

Thyroid function tests in thyroid and nonthyroid disease

Modern day evaluation of thyroid disorders requires a combination of accurate clinical judgement and reliable, sensitive, and specific thyroid functions tests. Principle among the latter are thyroxine (T4) 3, 5, 3'-triiodothyronine (T3), and thyroid-stimulating hormone (TSH). Also playing an important role in special situations are free thyroxine, an assessment of bound and unbound thyroid-binding globulin, TRH stimulation, long-acting thyroid stimulator (LATS), antibodies to thyroid hormone and to thyroid receptors. Basic to interpretation of these tests in the clinical setting is a comprehension of the relationship of the hypothalamus, the pituitary, and the thyroid gland as well as a knowledge of the peripheral metabolism of thyroxine and triiodothyronine. The role of each of these laboratory tests in the evaluation of hyper- and hypometabolic states, their alteration in nonthyroid and other endocrine disorders, and the effects of environmental and physiological factors on these tests are reviewed.

Systemic amyloidosis involving two renal transplants

Two patients with primary amyloidosis, each of whom had received a renal transplant for chronic renal failure, developed amyloid in their allografts. In one patient amyloid was present primarily in glomeruli and to a lesser extent in the interstitial tissue. This patient developed renal failure necessitating retransplantation. In the second patient amyloid was seen in the interstitium and interlobular blood vessels. Minimal amyloid was present in the glomeruli. This patient died of cardiac amyloidosis with good graft function at the time of death. Of the several patients recorded in the literature with amyloid in renal allografts, our first patient is the only one to exhibit glomerular amyloid and failure of the graft. Amyloid in areas other than the glomerulus does not appear to be incompatible with satisfactory graft function.

Immunohistochemical demonstration of Toxoplasma gondii

A peroxidase-antiperoxidase method that demonstrates both free and encysted toxoplasmata in routinely prepared histologic sections is described. This technic and ultrastructural study were employed to confirm the presence of Toxoplasma gondii in the infected tissues of an immunosuppressed patient who had postmortem examination. An immunohistochemical method may be an aid in the diagnosis of toxoplasmosis.

Intervertebral chondrocalcinosis: A coincidental finding possibly related to previous surgery

Chondrocalcinosis of the intervertebral discs is a common finding in patients who have had prior surgical procedures involving the same or adjacent disc space. The crystals in the tissues have the characteristic morphologic and spectrophotometric features of calcium pyrophosphate dihydrate. None of the patients described herein had clinical or radiographic evidence of crystal accumulation in sites remote from the surgical procedure. We propose that the surgical trauma may have played a role in the induction of the crystal deposits.

Atypical germ cells preceding metachronous bilateral testicular tumors

This is the sixth reported case of metachronous testicular neoplasia in which a seminoma has preceded an embryonal carcinoma. Of particular note is the presence of atypical germ cells in the biopsy specimen of the gonad from which the embryonal carcinoma arose. There has developed recently an increasing awareness of germ cell atypia and carcinoma in situ. Pathologists examining testicular biopsies in the infertile patient should be alerted to this process.

Incipient germ cell tumor in a cryptorchid testis

A 13-year-old male who had bilateral cryptorchid testes since birth underwent testicular biopsies and subsequent left orchiectomy following a diagnosis of malignant germ cell tumor. No tumor mass was noted although the malignant cells were seen within the seminiferous tubules and the interstitium. Five recorded cases of in-situ or incipient germ cell neoplasms of the testes are reviewed; three were infertile, another had a cryptorchid testis, and the fifth was both infertile and cryptorchid. Two of these patients have developed frank carcinoma, which would suggest that the process represents an early phase of invasive germ cell neoplasia.

Comparison of an automated radioimmunoassay method and a competitive protein-binding method for evaluation of serum cortisol

A competitive protein-binding method (CPB) for serum cortisol determination has been compared with a newly developed automated radioimmunoassay (RIA) technic with respect to reproducibility and correlation of patient results. The RIA method uses an immobilized anti-cortisol antibody covalently coupled to the inner surface of a plastic cartridge. A mixture of 3H-labeled and unlabeled cortisol is passed through the cartridge to achieve separation of free and bound cortisol. The bound cortisol is later eluted to regenerate the antibody for the next sample. The RIA procedure had a day-to-day coefficient of variation (CV) of 7% at three cortisol levels. The CPB method had a day-to-day CV of 10% at a concentration of 8 microgram/dl. A comparison of 67 patient samples showed no statistically significant difference between the methods. The regression equation was RIA = 0.96 CPB + 0.14 microgram/dl, with a correlation of 0.92.

Diagnosis of pneumonia due to Pneumocystis by subsegmental pulmonary lavage via the fiberoptic bronchoscope

To assess the accuracy of pulmonary lavage in diagnosing pneumonia due to Pneumocystis, we used animals as a model and then prospectively studied 33 immunosuppressed adults with diffuse pulmonary infiltrates. In rats treated with cortisone, Pneumocystis organisms could be found in the effluent from lavage as early as in sections of pulmonary tissue, and the effluent from lavage remained diagnostic throughout the ten weeks of observation. Subsegmental lavage in adult patients was performed through the wedged fiberoptic bronchoscope. Pneumocystis organisms were demonstrated in seven patients by lavage, and no false-negative results were recorded. Pneumocystis organisms were readily identified among the sheets of alveolar macrophages seen in smears of the effluent from lavage that were stained with methenamine silver. Subsegmental lavage via the fiberoptic bronchoscope is an accurate and safe technique for establishing the diagnosis of pneumonia due to Pneumocystis in patients whose respiratory embarrassment or thrombocytopenia makes biopsy of the lung hazardous.

Creatine phosphokinase isoenzymes: a comparison of a kinetic and electrophoretic method in the diagnosis of myocardial infarction

A comparison has been made of the results of the levels of the MB isoenzyme of creatine phosphokinase by a kinetic and an electrophoretic method performed on patients suspected of having myocardial infarction. Reviewed in depth are those cases in which discrepant results have occurred. On the basis of the combined clinical and laboratory data, the kinetic method is a more sensitive but less specific indicator of myocardial necrosis. Thus, the kinetic method may be used as a screening test, with confirmation of positive results by electrophoresis.