On-site generated peroxy acetic acid (PAA) technology reduces Salmonella and Campylobacter on chicken wings

Peroxyacetic acid (PAA) is a widely used antimicrobial during poultry processing that requires to be shipped in a concentrated solution, stored under hazardous conditions and diluted for use. On-site PAA generation using nonhazardous ingredients can help eliminate transportation and storage issues at the processing plant and reduce the risk of occupational hazards. The objective of the proposed research was to 1) evaluate the efficacy of on-site generated PAA in reducing Salmonella and Campylobacter populations compared to the commercially available PAA stock solutions and 2) to perform color measurements to evaluate any deviations between treatments. PAA solutions at 50 and 100 ppm were used for treating the chicken wings. Fresh chicken wings (0.45 kg) were inoculated with a cocktail of nalidixic acid resistant Salmonella Typhimurium (STNR) and gentamicin resistant Campylobacter coli (CCGR) and immersed in PAA solutions (50 and 100 ppm) adjusted to pH 8.5 and 10.0 or 10.5, for either 10 s or 60 min. Treated chicken wings were rinsed for 1 min in chilled BPW (100 mL), serially diluted and plated on APC Petrifilm for Salmonella, spread plated on Campy-cefex agar supplemented with gentamicin (200 ppm) for Campylobacter enumeration. Immersion of chicken wings in 100 ppm PAA for 60 min irrespective of pH levels and PAA solutions resulted in greater microbial reductions (P < 0.05) of Salmonella by 1.68 and 1.42 log CFU/mL for SaniDate, 1.82 and 1.83 log CFU/mL for OxyFusion (on-site generated). For the same treatments, Campylobacter reductions of 1.59 and 1.36 log CFU/mL for SaniDate, 1.63 and 1.71 log CFU/mL for OxyFusion were achieved. The antimicrobial efficiency of PAA was not affected by pH and type of PAA solution. No significant differences (P > 0.05) in color were observed between treatments and controls. On-site generated PAA provides poultry processors an effective, safer, and less hazardous alternative to commercially available PAA solutions, ensuring poultry workers’ health and safety.

The CD33 short isoform is a gain-of-function variant that enhances Aβ1-42 phagocytosis in microglia

BACKGROUND

CD33 is genetically linked to Alzheimer's disease (AD) susceptibility through differential expression of isoforms in microglia. The role of the human CD33 short isoform (hCD33m), preferentially encoded by an AD-protective CD33 allele (rs12459419T), is unknown. Here, we test whether hCD33m represents a loss-of-function or gain-of-function variant.

METHODS

We have developed two models to test the role of hCD33m. The first is a new strain of transgenic mice expressing hCD33m in the microglial cell lineage. The second is U937 cells where the CD33 gene was disrupted by CRISPR/Cas9 and complemented with different variants of hCD33. Primary microglia and U937 cells were tested in phagocytosis assays and single cell RNA sequencing (scRNAseq) was carried out on the primary microglia. Furthermore, a new monoclonal antibody was developed to detect hCD33m more efficiently.

RESULTS

In both primary microglia and U937 cells, we find that hCD33m enhances phagocytosis. This contrasts with the human CD33 long isoform (hCD33M) that represses phagocytosis, as previously demonstrated. As revealed by scRNAseq, hCD33m+ microglia are enriched in a cluster of cells defined by an upregulated expression and gene regulatory network of immediate early genes, which was further validated within microglia in situ. Using a new hCD33m-specific antibody enabled hCD33m expression to be examined, demonstrating a preference for an intracellular location. Moreover, this newly discovered gain-of-function role for hCD33m is dependent on its cytoplasmic signaling motifs, dominant over hCD33M, and not due to loss of glycan ligand binding.

CONCLUSIONS

These results provide strong support that hCD33m represents a gain-of-function isoform and offers insight into what it may take to therapeutically capture the AD-protective CD33 allele.

MP3: ROLE OF HISTONE DEACTYLASE (HDAC) INHIBITORS IN ADULT T-CELL LYMPHOMA/LEUKEMIA (ATL)

Purpose of Study

ATL is a peripheral T-cell neoplasm(PTCL) associated with human T-cell lymphotropic virus-1 (HTLV-1) infection. Currently there is no established therapy for relapsed/refractory disease. Initial in-vitro studies of HDAC inhibitors showed selective apoptosis of HTLV-1 infected T cell lines. In phase II trial for relapsed/refractory PTCL, 2 patients had EBV and 1 patient had HBV reactivation. It was unclear if this was from HDAC induced immunosuppression or direct promotion of viral replication or underlying disease process. All HDAC inhibitors trials in last 6 years excluded ATL patients although they are approved for this disease. We here describe our experience of 3 patients with relapsed/refractory ATL treated with HDAC inhibitor romidepsin.

Methods Used

Chart review of patients with relapsed/refractory ATL treated with romidepsin at King's County Hospital.

Summary of Results

Case 1: 43 year old male with acute ATL who progressed on EPOCH after 4 cycles. Romidepsin was started at 14 mg/m2 IV Day 1, 8, 15 Q28 days. He tolerated cycle 1 well but continued to have progressive disease. Patient died 40 days after initiation of therapy from infection.

Case 2: 37 year old male with acute ATL who had disease progression on EPOCH×2 cycles. He was started on romidepsin 10 mg/m2 IV (dose reduced due to T. bili 3.5 gm/dl). After first dose, his platelets dropped to to 20 k/mm3 necessitating treatment delay and dose reduction to 6 mg/m2. He had temporary response as evidenced by reduction in WBC count from 103 kmm3 to 5 k/mm3 and improvement in liver function. He only received 1 cycle and died on Day 50 from disease progression.

Case 3: 47 year old male with ATL lymphoma intially treated with CHOP×6 cycles and relapsed after 1 year with peripheral lymphocytosis to 57 k/mm3 and diffuse lymphadenopathy. He received ICE×2 cycles with progressive disease. He was started on romidepsin 14 mg/m2. He received 1 dose and had Grade IV anemia/thrombocytopenia. He developed urosepsis and expired on Day 20.

Conclusions

In our small experience of romidepsin in relapsed/refractory ATL, patients appear to have modest response rates and higher rate of cytopenias when compared to other PTCL subtypes in clinical trials. Given the concerns for viral reactivation and lack of data for use of romidepsin in ATL, it should be used cautiously.

P10: IBRUTINIB ASSOCIATED AUTOIMMUNE HEMOLYTIC ANEMIA

Purpose of Study

Autoimmune hemolytic anemia (AIHA) is a common phenomenon in Chronic lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL) accounting for about 4–7% of cases. AIHA is commonly associated with certain conventional chemotherapy agents used in CLL/SLL. Ibrutinib, bruton tyrosine kinase inhibitor is category 1 indication for high risk (del 17p) and relapsed/refractory CLL. Literature review reports 11cases of Ibrutinib associated AIHA.

We report a case of AIHA precipitated by Ibrutinib in an high risk CLL patient, with prior history of AIHA.

Methods Used

Patient is an 81 year old black man diagnosed with asymptomatic Stage I CLL (del 17p) in 2010 and was on active surveillance. He developed AIHA in 2012, with good response to steroids and Rituximab. Subsequently he received 8 cycles of rituximab for symptomatic CLL with resolution of symptoms. In 9/2014, noted to have progression of disease with worsening B symptoms, leukocytosis and lymphadenopathy. He was started on Ibrutinib 420 mg PO daily with regression of lymphadenopathy within 3 weeks of therapy, but presented with symptomatic anemia with hemoglobin of 3 gm/dl, positive direct Coomb's test, elevated reticulocyte count and LDH consistent with AIHA. WBC elevated at 360 K/uL from baseline of 150 K/uL and hemoglobin fell to 3 g/dl from 10 g/dl since Ibrutinib was initiated. Ibrutinib was held and patient received high dose prednisone followed by IVIG and cautious transfusion with minimal improvement in hemoglobin. Hemoglobin slowly up trended with weekly Rituximab and high dose steroids and remained stable around 10 gm/dl after 4 weeks of Rituximab. Ibrutinib was subsequently restarted with overall clinical improvement.

Summary of Results

In our patient, occurrence of AIHA falls in between 2–4 weeks as other reported cases suggesting that Ibrutinib could be a likely precipitating factor.

Conclusions

Review of data, reveals that 22% of patients had history of AIC prior to Ibrutinib, however occurrence of AIHA on Ibrutinib seems to be less common (0.7%).Mechanism of action of Ibrutinib associated cytopenias remains unclear. It was hypothesized that it may be due to IL-2 induced kinase inhibition by Ibrutinib, and needs further investigation.

P11: ADULT T CELL LYMPHOMA (ATL) MASQUERADING AS FACIAL NERVE PARALYSIS

Purpose of Study

ATL is a rare and aggressive peripheral T-cell neoplasm characterized by clonal human T-cell lymphotropic virus type-1 (HTLV-1) proviral DNA integration with host T lymphocytes.These patients commonly present with lymphadenopathy, skin rash, fever, fatigue or altered mental status. The prevalence of CNS disease varies from 3 to 50% and is always in the presence of systemic disease. Isolated cranial neuropathy as a presenting symptom has not been described in literature.

Methods Used

Retrospective chart review and review of literature.

Summary of Results

49 year old Caribbean male presented with 2 month history of left sided headache, 5 weeks of right sided jaw numbness and pain which progressed to contralateral side. He was now unable to smile and had food falling from the side of his mouth. He denied fever, fatigue, night sweats, rash, weakness or abnormal lumps. He had normal mental status and good motor strength. Facial exam reveal bilateral upper and lower facial paralysis, left lateral rectus palsy and horizontal gaze diplopia. Rest of the physical exam was unremarkable. Labs revealed WBC of 6 k/mm3 with normal differential, HB 16.5 gm/dl and platelets 238 k/mm3. Complete metabolic profile and peripheral smear was normal. MRI Brain showed irregular, fusiform enhancement of left trigeminal nerve, bilateral facial and abducent nerves. CSF flow cytometry showed clonal CD4+ CD25+ T cell population. HTLV-1 serology was reactive. Left infraorbital nerve biopsy confirmed involvement with ATL. CT Chest/abdomen/pelvis did not reveal enlarged lymphadenopathy. He was started on treatment with EPOCH and twice weekly intrathecal methotrexate for 4 months with clearance of CNS fluid. His jaw pain and vision improved but facial nerve paralysis persisted. He developed local relapse four months after treatment and was treated with high dose methotrexate for 5 cycles. Ultimately his performance status deteriorated and he succumbed to the disease progression.

Conclusions

This case illustrates the unique presentation of this disease and gives an insight on one treatment approach. This patient achieved remission with our approach of aggressive chemotherapy with intrathecal methotrexate although the duration of remission was short lived.

P8: CHEMOTHERAPY INDUCED IMMUNE THROMBOCYTOPENIA-AN ENTITY TO KEEP IN MIND!

Purpose of Study

Thrombocytopenia during chemotherapy is not always due to myelosuppression. We report an unusual case of isolated acute thrombocytopenia after oxaliplatin and irinotecan administration. We reviewed 11 reported cases to better understand the nature of the presentation and variability in response to treatment.

Case Report

Patient is a 63 year old female with metastatic colon cancer treated with palliative chemotherapy with FOLFOX. Follwing her 14th cycle she had an episode of acute drop in platelet count to 8,000/microliter. Peripheral smear revealed no evidence of thrombotic microangiopathy. She was managed with supportive platelet transfusions with slow recovery of platelet count. Subsequently she was treated with second line chemotherapy with FOLFIRI. Following the first cycle of Irinotecan, she again had a catastrophic drop in platelets from 136,000/microliter to 6,000/microliter within 10 hours. Due to this recurrent episode, a drug mediated thrombocytopenia was suspected and work up was initiated. She was initially treated with dexamethasone without a significant response. Platelet count normalized after 7 days with supportive platelet transfusions.

Methods Used

Blood was tested for drug dependent platelet antibodies by Flow Cytometry at the Platelet and Neutrophil Immunology Laboratory at the Blood Center of Wisconsin.

Summary of Results

The patient's serum showed evidence of drug dependent platelet antibodies to both oxaliplatin and irinotecan.

Conclusions

Drug mediated immune thrombocytopenia is not uncommon. Time to severe acute thrombocytopenia and platelet recovery time varied post exposure of the drug. It is unclear whether steroid or IVIG administration had any effect on the platelet recovery time. Recovery from thrombocytopenia was observed in all 11 cases after the discontinuation of the insulting agent. Confirmation of the presence of drug dependent platelet antibodies against the chemotherapeutic agent by flow cytometry essential for diagnosis. This would be the first reported case of acute thrombocytopenia to two different chemotherapeutic agents in the same patient. Whether the reaction is two different mechanisms or if there is a cross reactivity between Oxaliplatin and Irinotecan has yet to be investigated.

The fate and significance of retained staples after stapled haemorrhoidopexy

AIM

We studied the fate of staples after stapled haemorrhoidectomy (SH) and reviewed the complications they may cause.

METHOD

A survey was carried among 16 surgeons experienced at performing SH to assess their knowledge regarding retained staples. In addition, plain pelvic radiology was used to visualize residual staples at different time intervals after SH in 45 patients.

RESULTS

Ten (63%) surgeons informed their patients that the staples would be shed within 3 months of SH. Regardless of the timing of surgery, part of the staple line was radiologically visible in all patients, and in 19 patients (45%) the staple line was completely visible.

CONCLUSION

Contrary to the common belief, the majority of staples are retained after SH.

Brain metastases (BM) in breast (BC) and lung cancer (LC) patients

e12029

Background: Most BM arise from BC or LC. Few studies compare their attributes and distribution, though BC BM have been reported to more often involve the cerebellum. Methods: Brain scanning was for clinical evidence of BM. Contrast-enhanced computer-automated tomograms (CT) or magnetic resonance images (MRI) of brains of all BC and LC patients irradiated for BM between 1996 and 2008 were reviewed. BC epidermoid growth factor receptor2 (HER-2) expression was determined. Results: Data was from 63 BC and 59 LC patients; 58% of the BC and 55% of the LC patients had MRIs. MRIs showed more cerebellar BM (p = 0.047). Primary to BM diagnosis intervals were shorter for LC than for BC patients (p = 0.001), but LC BM were more edematous (0.019). BC patients had more cerebellar BM (p = 0.004) than LC patients, and more BM in the cerebellum only (p = 0.017). LC patient gender and small cell histology did not correlate with cerebellar BM. Both cerebrums and cerebellums of BC patients had more BM than those with LC (p = 0.020; 0.013). Cerebellar BMs were more frequent in brains with more cerebral BM (p = 0.0020). Amongst BC over-expressing HER-2 was a trend to more cerebellar BM (p = 0.072). Conclusions: LC BM, which elicit more edema, produce symptoms earlier than BC BM. There are larger numbers of BC BM, perhaps due to BC's longer disease course and responsiveness to therapy. BC causes more cerebellar mets than LC, often without cerebral BM. This may be due both to the larger number of BC BM, and a predilection for the cerebellum. Periodic brain MRI, more sensitive than CT to posterior fossa lesions, may be indicated in some BC patients, and early radiation may control multiple small BM.

No significant financial relationships to disclose.

Dissecting the electrostatic interactions and pH-dependent activity of a family 11 glycosidase

Previous studies of the low molecular mass family 11 xylanase from Bacillus circulans show that the ionization state of the nucleophile (Glu78, pK(a) 4.6) and the acid/base catalyst (Glu172, pK(a) 6.7) gives rise to its pH-dependent activity profile. Inspection of the crystal structure of BCX reveals that Glu78 and Glu172 are in very similar environments and are surrounded by several chemically equivalent and highly conserved active site residues. Hence, there are no obvious reasons why their apparent pK(a) values are different. To address this question, a mutagenic approach was implemented to determine what features establish the pK(a) values (measured directly by (13)C NMR and indirectly by pH-dependent activity profiles) of these two catalytic carboxylic acids. Analysis of several BCX variants indicates that the ionized form of Glu78 is preferentially stabilized over that of Glu172 in part by stronger hydrogen bonds contributed by two well-ordered residues, namely, Tyr69 and Gln127. In addition, theoretical pK(a) calculations show that Glu78 has a lower pK(a) value than Glu172 due to a smaller desolvation energy and more favorable background interactions with permanent partial charges and ionizable groups within the protein. The pK(a) value of Glu172 is in turn elevated due to electrostatic repulsion from the negatively charged glutamate at position 78. The results also indicate that all of the conserved active site residues act concertedly in establishing the pK(a) values of Glu78 and Glu172, with no particular residue being singly more important than any of the others. In general, residues that contribute positive charges and hydrogen bonds serve to lower the pK(a) values of Glu78 and Glu172. The degree to which a hydrogen bond lowers a pK(a) value is largely dependent on the length of the hydrogen bond (shorter bonds lower pK(a) values more) and the chemical nature of the donor (COOH > OH > CONH(2)). In contrast, neighboring carboxyl groups can either lower or raise the pK(a) values of the catalytic glutamic acids depending upon the electrostatic linkage of the ionization constants of the residues involved in the interaction. While the pH optimum of BCX can be shifted from -1.1 to +0.6 pH units by mutating neighboring residues within the active site, activity is usually compromised due to the loss of important ground and/or transition state interactions. These results suggest that the pH optima of an enzyme might be best engineered by making strategic amino acid substitutions, at positions outside of the "core" active site, that electrostatically influence catalytic residues without perturbing their immediate structural environment.

Malignant fibrous histiocytoma arising in the upper posterior triangle of the neck

We describe the case of a 59-year-old man who came to us with a right neck mass of 4 to 5 months' duration. A histologic diagnosis of malignant fibrous histiocytoma was made, and the patient underwent wide local excision and neck dissection followed by postoperative radiation therapy. We briefly discuss the characteristics and treatment of this rare entity.

Hydrogen bonding and catalysis: a novel explanation for how a single amino acid substitution can change the pH optimum of a glycosidase

The pH optima of family 11 xylanases are well correlated with the nature of the residue adjacent to the acid/base catalyst. In xylanases that function optimally under acidic conditions, this residue is aspartic acid, whereas it is asparagine in those that function under more alkaline conditions. Previous studies of wild-type (WT) Bacillus circulans xylanase (BCX), with an asparagine residue at position 35, demonstrated that its pH-dependent activity follows the ionization states of the nucleophile Glu78 (pKa 4.6) and the acid/base catalyst Glu172 (pKa 6.7). As predicted from sequence comparisons, substitution of this asparagine residue with an aspartic acid residue (N35D BCX) shifts its pH optimum from 5.7 to 4.6, with an approximately 20% increase in activity. The bell-shaped pH-activity profile of this mutant enzyme follows apparent pKa values of 3.5 and 5.8. Based on 13C-NMR titrations, the predominant pKa values of its active-site carboxyl groups are 3.7 (Asp35), 5.7 (Glu78) and 8.4 (Glu172). Thus, in contrast to the WT enzyme, the pH-activity profile of N35D BCX appears to be set by Asp35 and Glu78. Mutational, kinetic, and structural studies of N35D BCX, both in its native and covalently modified 2-fluoro-xylobiosyl glycosyl-enzyme intermediate states, reveal that the xylanase still follows a double-displacement mechanism with Glu78 serving as the nucleophile. We therefore propose that Asp35 and Glu172 function together as the general acid/base catalyst, and that N35D BCX exhibits a "reverse protonation" mechanism in which it is catalytically active when Asp35, with the lower pKa, is protonated, while Glu78, with the higher pKa, is deprotonated. This implies that the mutant enzyme must have an inherent catalytic efficiency at least 100-fold higher than that of the parental WT, because only approximately 1% of its population is in the correct ionization state for catalysis at its pH optimum. The increased efficiency of N35D BCX, and by inference all "acidic" family 11 xylanases, is attributed to the formation of a short (2.7 A) hydrogen bond between Asp35 and Glu172, observed in the crystal structure of the glycosyl-enzyme intermediate of this enzyme, that will substantially stabilize the transition state for glycosyl transfer. Such a mechanism may be much more commonly employed than is generally realized, necessitating careful analysis of the pH-dependence of enzymatic catalysis.

Subsite mapping of the human pancreatic alpha-amylase active site through structural, kinetic, and mutagenesis techniques

We report a multifaceted study of the active site region of human pancreatic alpha-amylase. Through a series of novel kinetic analyses using malto-oligosaccharides and malto-oligosaccharyl fluorides, an overall cleavage action pattern for this enzyme has been developed. The preferred binding/cleavage mode occurs when a maltose residue serves as the leaving group (aglycone sites +1 and +2) and there are three sugars in the glycon (-1, -2, -3) sites. Overall it appears that five binding subsites span the active site, although an additional glycon subsite appears to be a significant factor in the binding of longer substrates. Kinetic parameters for the cleavage of substrates modified at the 2 and 4' ' positions also highlight the importance of these hydroxyl groups for catalysis and identify the rate-determining step. Further kinetic and structural studies pinpoint Asp197 as being the likely nucleophile in catalysis, with substitution of this residue leading to an approximately 10(6)-fold drop in catalytic activity. Structural studies show that the original pseudo-tetrasaccharide structure of acarbose is modified upon binding, presumably through a series of hydrolysis and transglycosylation reactions. The end result is a pseudo-pentasaccharide moiety that spans the active site region with its N-linked "glycosidic" bond positioned at the normal site of cleavage. Interestingly, the side chains of Glu233 and Asp300, along with a water molecule, are aligned about the inhibitor N-linked glycosidic bond in a manner suggesting that these might act individually or collectively in the role of acid/base catalyst in the reaction mechanism. Indeed, kinetic analyses show that substitution of the side chains of either Glu233 or Asp300 leads to as much as a approximately 10(3)-fold decrease in catalytic activity. Structural analyses of the Asp300Asn variant of human pancreatic alpha-amylase and its complex with acarbose clearly demonstrate the importance of Asp300 to the mode of inhibitor binding.

Sugar ring distortion in the glycosyl-enzyme intermediate of a family G/11 xylanase

The 1.8 A resolution structure of the glycosyl-enzyme intermediate formed on the retaining beta-1,4-xylanase from Bacillus circulans has been determined using X-ray crystallographic techniques. The 2-fluoro-xylose residue bound in the -1 subsite adopts a 2,5B (boat) conformation, allowing atoms C5, O5, C1, and C2 of the sugar to achieve coplanarity as required at the oxocarbenium ion-like transition states of the double-displacement catalytic mechanism. Comparison of this structure to that of a mutant of this same enzyme noncovalently complexed with xylotetraose [Wakarchuk et al. (1994) Protein Sci. 3, 467-475] reveals a number of differences beyond the distortion of the sugar moiety. Most notably, a bifurcated hydrogen bond interaction is formed in the glycosyl-enzyme intermediate involving Heta of Tyr69, the endocyclic oxygen (O5) of the xylose residue in the -1 subsite, and Oepsilon2 of the catalytic nucleophile, Glu78. To gain additional understanding of the role of Tyr69 at the active site of this enzyme, we also determined the 1.5 A resolution structure of the catalytically inactive Tyr69Phe mutant. Interestingly, no significant structural perturbation due to the loss of the phenolic group is observed. These results suggest that the interactions involving the phenolic group of Tyr69, O5 of the proximal saccharide, and Glu78 Oepsilon2 are important for the catalytic mechanism of this enzyme, and it is proposed that, through charge redistribution, these interactions serve to stabilize the oxocarbenium-like ion of the transition state. Studies of the covalent glycosyl-enzyme intermediate of this xylanase also provide insight into specificity, as contacts with C5 of the xylose moiety exclude sugars with hydroxymethyl substituents, and the mechanism of catalysis, including aspects of stereoelectronic theory as applied to glycoside hydrolysis.

Cloning, mutagenesis, and structural analysis of human pancreatic alpha-amylase expressed in Pichia pastoris

Human pancreatic alpha-amylase (HPA) was expressed in the methylotrophic yeast Pichia pastoris and two mutants (D197A and D197N) of a completely conserved active site carboxylic acid were generated. All recombinant proteins were shown by electrospray ionization mass spectrometry (ESI-MS) to be glycosylated and the site of attachment was shown to be Asn461 by peptide mapping in conjunction with ESI-MS. Treatment of these proteins with endoglycosidase F demonstrated that they contained a single N-linked oligosaccharide and yielded a protein product with a single N-acetyl glucosamine (GlcNAc), which could be crystallized. Solution of the crystal structure to a resolution of 2.0 A confirmed the location of the glycosyl group as Asn461 and showed that the recombinant protein had essentially the same conformation as the native enzyme. The kinetic parameters of the glycosylated and deglycosylated wild-type proteins were the same while the k(cat)/Km values for D197A and D197N were 10(6)-10(7) times lower than the wild-type enzyme. The decreased k(cat)/Km values for the mutants confirm that D197 plays a crucial role in the hydrolytic activity of HPA, presumably as the catalytic nucleophile.

Atypical cutaneous lymphoproliferative disorder in patients with HIV infection

BACKGROUND

An inflammatory pruritic eruption which is characterized histologically by CD8+, atypical lymphocytes has been described in human immunodeficiency virus (HIV)-infected patients. This disorder has been described as "pseudo-Sezary" or a "cutaneous T cell lymphoma (CTCL)-simulant", however, as these patients do not resemble CTCL clinically, and the relationship between this entity and CTCL is unclear, a more descriptive term is "atypical cutaneous lymphoproliferative disorder" (ACLD). The purpose of this study is to categorize the clinical, histologic, and immunophenotypic features of 16 HIV-infected patients with this skin disorder seen at the New York Department of Veterans Affairs Medical Center.

METHODS

A retrospective chart review was conducted on 16 HIV-infected patients with a histologic diagnosis of an atypical cutaneous lymphoproliferative infiltrate on skin biopsy. Skin biopsies were reviewed, and histologic features noted. Immunophenotyping was performed on 14 out of 16 samples; electron microscopy was performed on samples from five patients. Clinical manifestations, disease course, medication history, and response to treatment were noted.

RESULTS

The patients presented with a pruritic, persistent, generalized, papular eruption. Pigment changes, including hyperpigmentation and hypopigmentation were common. Histologically, lesional biopsies were characterized by a superficial and deep polymorphous infiltrate with atypical lymphocytes which were CD8+ predominant, Ki-1 negative, and occasionally CD7 antigen depleted. Sezary-like cells were present in the infiltrate in four out of five patients by electron microscopy. None of the patients has systemic manifestations of lymphoma; however, one of the 16 patients eventually developed frank CTCL.

CONCLUSIONS

HIV-infected patients can present with a pruritic, widespread disorder, often with pigment changes characterized by an atypical cutaneous lymphocytic infiltrate. This clinicopathologic disorder is a rare, reactive inflammatory condition which generally occurs in late stage HIV infection and rarely progresses to frank lymphoma.

Phase II study of CI-980 (NSC 635370) in patients with previously treated advanced soft-tissue sarcomas

Doxorubicin and ifosfamide are the two most active agents in the treatment of soft-tissue sarcomas. Patients whose tumors have failed these two drugs have very limited systemic therapy options. It is, therefore, important to identify newer drugs with activity against this disease. CI-980 is a synthetic mitotic inhibitor that binds to tubulin at the colchicine binding site and inhibits the polymerization of tubulin and blocks cell cycle progression in mitosis. Given its broad spectrum activity against several solid tumor models in vivo, we decided to perform a phase 2 study of this drug in previously treated soft-tissue sarcomas. A total of 18 eligible and evaluable patients were entered in the first stage of the trial. The median age was 53 yrs (range, 17-72). No objective responses have been noted. Six patients had stable disease after a median of 3.5 cycles of chemotherapy while 12 others had progressive disease. A total of 48 cycles were administered, 42 of which were administered at dose level 0 (4.5 mg/m2/d x 3). The median AGC nadir was 1.2/microl(0.1 -4.7) on day 10 and the median platelet nadir was 150,000/microl (31,000-338,000). Twenty cycles were complicated with grade 3-4 neutropenia and two cycles were complicated with FUO. There were no CNS toxicities. One patient had a grade 1 thrombophlebitis in 2 cycles and one other patient had a grade 4 thrombophlebitis in one cycle. In conclusion, CI-980 was well tolerated at this dose and schedule but inactive in soft-tissue sarcomas.

Lung adenocarcinomas metastatic to the brain with and without ultrastructural evidence of rootlets: an electron microscopic and immunohistochemical study using cytokeratins 7 and 20 and villin

Adenocarcinomas metastatic to brain from lung or colon may pose differentiation difficulties. Ultrastructurally, both may have brush borders with rootlets. This study examines the ultrastructural morphology and immunohistochemical expression of villin (associated with rootlets), cytokeratin 7 (present in lung adenocarcinomas), and cytokeratin 20 (present in colon adenocarcinomas) in 19 formalin-fixed sequential surgical biopsies of lung adenocarcinomas metastatic to brain as compared to 13 colonic adenocarcinoma metastases. Of lung tumor metastases, mucinous differentiation with rootlets was most common [6/19(32%)]. All colon tumor metastases were cytokeratin 7(-), 20(+), and profusely villin(+). Well-formed rootlets were seen. All lung metastases were cytokeratin 7(+) and 20(-). 5/6(83%) lung metastases with rootlets were focally villin(+). 12/13(95%) without rootlets were villin(-). Rootlets are extremely common in lung adenocarcinoma metastatic to brain. Villin immunoreactivity closely correlates with rootlets. Its distribution is a useful adjunct to cytokeratin 7 and 20 in differentiation of lung versus colon adenocarcinomas metastatic to the brain.

Gangrene of Meckel's diverticulum secondary to axial torsion: a rare complication

A Meckel's diverticulum may result in a number of complications including hemorrhage, obstruction, and inflammation. We report a case of a gangrenous Meckel's diverticulum secondary to axial torsion, which has been reported only four times in adults and once in children in the past 28 years.

Villin, cytokeratin 7, and cytokeratin 20 expression in pulmonary adenocarcinoma with ultrastructural evidence of microvilli with rootlets

Villin (V) is a glycoprotein of microvilli associated with rootlet formation. Most colonic adenocarcinomas have a V positive (+), cytokeratin (CK) 20 (+), CK7-negative (-) immunophenotype; most lung adenocarcinomas have a CK20(-), CK7(+) immunophenotype. The reports of villin immunoreactivity in lung adenocarcinoma range from 6% to 68% in studies using various fixations and varied anti-villin antibodies. Some lung adenocarcinomas have microvilli with rootlets leading to possible diagnostic confusion with metastatic colonic adenocarcinoma to lung. Nine primary lung adenocarcinomas with rootlets on ultrastructure (including four bronchioloalveolar carcinomas [BAC]), four metastatic lung adenocarcinomas with rootlets, nine metastatic colon adenocarcinomas to lung, and 10 randomly selected lung adenocarcinomas without rootlets (including five BAC), were immunostained with monoclonal antibodies to villin (1D2C3), CK7 (OV-TL12/30), and CK20 (Ks20.8) using a streptavidin peroxidase technique with heat-induced epitope retrieval. All primary lung adenocarcinomas with rootlets were CK7(+) CK20(-), and six of nine (67%) were V(+). Cytoplasmic villin positivity occurred in a diffuse--five of nine (56%), focal--two of nine (22%), or brush border pattern--two of nine (22%). Two of four metastatic lung adenocarcinomas with rootlets were V(+). One metastatic lung adenocarcinoma had a CK7(+), CK20(+), V(-) phenotype. All metastatic colonic adenocarcinomas were V(+), CK20(+), CK7(-), and 1 of 10 (10%) lung adenocarcinomas without rootlets was V(+), and all 10 were CK20(-), and CK7(+). In summary, villin positivity is more common in lung adenocarcinoma with rootlets (67%) than those without rootlets (10%). AU primary lung adenocarcinomas were CK7(+), CK20(-). The combination of villin, CK 7, and CK 20 is helpful in differentiating metastatic colon adenocarcinoma from lung adenocarcinoma with rootlets.

CD44 and its v6 spliced variant in lung tumors: a role in histogenesis?

BACKGROUND

CD44 is a polymorphic family of cell surface glycoproteins with a variety of functions including participation in cell adhesion and migration as well as modulation of cell-matrix interactions. Expression of the standard form of CD44 (CD44s) and its variant isoforms has been shown in both normal and neoplastic tissue and holds promise as a prognostic indicator.

METHODS

The authors investigated the expression of CD44s and its v6 isoform (CD44v6) immunohistochemically in 7 fetal lungs (gestational age between 11-36 weeks) and in 80 lung tumors of various histologic types, degrees of differentiation, and clinical stages.

RESULTS

In the fetal lung, CD44v6 was expressed as membranous and luminal staining of epithelial cells throughout gestation and basal staining of bronchial epithelium late in gestation. Nonneoplastic adult lung showed CD44v6 expression that was restricted to epithelial cells with membranous staining of basal bronchial cells and squamous metaplasia as well as basolateral membranous staining of type 2 pneumocytes. CD44s showed similar but less intense staining and was in addition present on lymphocytes and macrophages. Tumorlets and neuroepithelial bodies were CD44v6 negative. Nearly all squamous cell carcinomas (97%) were positive for CD44v6 with patterns similar to squamous metaplasia and with more intense staining at the periphery of tumor nests. Most adenocarcinomas (90%) were CD44v6 negative whereas most bronchioloalveolar cell carcinomas (71%) were CD44v6 positive with patterns similar to that in type 2 pneumocytes. Most large cell carcinomas (71%), carcinoid tumors (67%), and all small cell carcinomas were CD44v6 negative. CD44v6 expression did not correlate with clinical stage. CD44v6 expression in lymph node metastases was identical to that of the primary tumor.

CONCLUSIONS

The results of the current study show that CD44v6 is localized differently in fetal and adult lung, suggesting a difference in function. In the fetal lung, it may modulate growth factors important in morphogenesis and maturation. In the adult nonneoplastic lung, CD44v6 is associated with stem cells, namely basal cells and type 2 pneumocytes, and may act to anchor these cells to the matrix and be important in migration during repair or neoplasia. In addition, CD44v6 expression is maintained throughout tumorigenesis in squamous cell carcinoma and bronchioloalveolar cell carcinoma, suggesting a histogenetic relationship between the stem cells and the respective tumors. Conversely, most neuroendocrine tumors and the cells of the dispersive neuroendocrine system do not express CD44v6, implying a separate histogenetic lineage in these tumors.

Human parvovirus B19 in bone marrows from adults with acquired immunodeficiency syndrome: a comparative study using in situ hybridization and immunohistochemistry

Human parvovirus B19, which infects and lyses erythroid precursors, can cause severe anemia in patients with immunodeficiency. The incidence of parvovirus infection in adult acquired immunodeficiency syndrome (AIDS) patients is unknown. Eighty-one archival formalin-fixed, paraffin-embedded (FFPE) bone marrow biopsies from 73 AIDS adults were immunostained with monoclonal R92F6 against B19 VP1 and VP2 capsid proteins using streptavidin peroxidase and streptavidin alkaline phosphatase techniques. In addition, the same tissues were hybridized in situ with a digoxigenin-labeled parvovirus B19 DNA probe. Five FFPE bone marrows, from 3 HIV-negative patients with positive immunoglobulin M (IgM) serology for parvovirus B19, and 1 parvovirus B19-infected fetal liver were positive controls. By immunoperoxidase, all tissues were negative with R92F6 except the fetal liver, which exhibited strong positivity predominantly in viral inclusions. With immunoalkaline phosphatase, all positive controls were immunoreactive with R92F6; however, the AIDS marrows were negative. With in situ hybridization (ISH), all positive controls and 7 of 81 (8.6%) of AIDS marrows were positive for B19 parvovirus DNA. We conclude that ISH is more sensitive than R92F6 immunohistochemistry in parvovirus B19 detection. A small but significant number of bone marrows from AIDS adults shows evidence of human parvovirus B19 infection.

A review of the amendments to the Criminal Code of Canada (Mental Disorder)

On February 4, 1992, Bill C-30, an Act to Amend the Criminal Code of Canada (Mental Disorder), the National Defence Act and the Young Offenders Act, was officially proclaimed. The authors provide an overview of this legislation and raise some concerns regarding certain sections of the Criminal Code.

Rapid renal failure in AIDS-associated focal glomerulosclerosis

We studied the clinical features, pathologic findings, and course of 18 patients who were found to have glomerular disease at the time of hospitalization with manifestations of acquired immunodeficiency syndrome or acquired immunodeficiency syndrome-related complex at New York University Medical Center, New York, NY, during 1984 through 1987. Focal glomerulosclerosis, characterized by segmental and/or global collapse of capillary walls, was observed in 15 of these patients; mesangial proliferation in 2, and membranous nephropathy in 1. Those with focal glomerulosclerosis typically demonstrated heavy proteinuria without edema or hypertension and progressed rapidly to renal failure in less than 1 year from the time of discovery. This form of focal glomerulosclerosis is characterized by a fulminant course, the collapse type of sclerosis, and the frequent occurrence of uremia without advanced glomerular obliteration. The absence of widespread glomerular sclerosis and the rapid course suggest that unique renal hemodynamic mechanisms may be responsible for the progression.

Leiomyosarcoma of scrotum

Leiomyosarcoma of the scrotum is a rare tumor that is best treated by wide local excision. Lymphatic metastasis is rare. To date a total of 14 cases have been reported.

Jaundice in Plasmodium falciparum

Thirty-two patients of smear positive Plasmodium falciparum malaria having jaundice were analysed retrospectively. Majority of the cases were in the age group of 31-40 years. Serum bilirubin levels ranged from 2 mg to 40 mg%. Fourteen (42.6%) had serum bilirubin above 10 mg%. Conjugated bilirubinaemia was found in twenty one patients (65.5%), unconjugated in 4 (12.5%) while 7 patients (21.8%) had a mixed pattern. Serum transaminases were high in 21.8% patients. Twenty five patients (78%) had associated azotaemia, 11(34.3%) had intravascular haemolysis and 3(9.3%) had possible cerebral malaria. Hepatosplenomegaly was seen in all the 32 patients. Mortality was 21% but none died of hepatic encephalopathy. Histologically the most consistent finding in liver biopsies was reticulo-endothelial cell hyperplasia. Pigmentation in kupffer cells, fatty change, sinusoidal and portal infiltration and cholestasis were the other features seen.

Long-term effects of etretinate on the liver in psoriasis

Etretinate is an aromatic retinoid and derivative of vitamin A soon to be approved for general use in the U.S. as therapy for severe psoriasis. We report on liver morphology and function in 18 subjects who received the drug for at least 5 years as part of a clinical trial. The majority (14) suffered no or mild and reversible structural liver changes; mild transient elevations in serum triglyceride and liver enzymes were noted occasionally. Of the remaining four patients, mild periportal fibrosis was documented in two, another had changes similar to chronic active hepatitis, and a fourth had cirrhosis that was unrelated to alcohol use. Liver function data, cumulative drug dose, and treatment duration were generally not reflective of these changes. The results of this study suggest a need for periodic liver biopsy to monitor patients on long-term etretinate therapy.

High-dose corticosteroids as adjunct therapy in severe Pneumocystis carinii pneumonia

Three patients with severe Pneumocystis carinii pneumonia and acquired immunodeficiency syndrome, not responding to specific therapy with trimethoprim/sulfamethoxazole, were treated with a 24-hour course of high-dose methylprednisolone. Rapid improvements in the clinical status and the chest X-rays were detected. In two of the patients, in whom lung biopsy was performed before initiation of corticosteroids, an intense interstitial mononuclear cell infiltrate was seen. In the one patient who had lung biopsy after corticosteroid therapy, a scanty amount of mononuclear cells was demonstrated in the interstitium. Our experience suggests that corticosteroids may be useful as adjunctive agents in the treatment of severe P. carinii pneumonia not responding to specific anti-Pneumocystis therapy. This may be a result of inhibition of mononuclear cell accumulation within the lung by the steroid therapy.

Proviral DNA of a retrovirus, human T-cell leukemia virus, in two patients with AIDS

The acquired immune deficiency syndrome (AIDS) is characterized by T-lymphocyte dysfunction and is frequently accompanied by opportunistic infections and Kaposi's sarcoma. Human T-cell leukemia virus (HTLV) is associated with T-cell malignancies and can transform T lymphocytes in vitro. In an attempt to find evidence of HTLV infection in patients with AIDS, DNA from samples of peripheral blood lymphocytes from 33 AIDS patients was analyzed by Southern blot-hybridization with a radiolabeled cloned HTLV DNA probe. Analysis of DNA from both the fresh (uncultured) lymphocytes and from T cells cultured with T-cell growth factor revealed the presence of integrated HTLV proviral sequences in lymphocytes from two of the patients, both of whom had antibody to HTLV. The proviral sequences could not be detected in blood samples obtained from these individuals at a later date, consistent with the possibility that the population of infected cells had become depleted.

Cytoplasmic fragments causing spurious platelet counts in hairy cell leukemia: ultrastructural characterization

A patient with hairy cell leukemia had a spuriously elevated automated platelet count because of cytoplasmic fragments. The cytoplasmic fragments observed with electron microscopy were found in the same fraction as the platelets (platelet-rich plasma). Ultrastructural examination confirmed the hairy cell cytoplasmic origin of these fragments because of their obvious difference from platelet ultrastructure. Cytoplasmic fragments as a cause of spuriously high automated platelet counts should be considered in all cases of hairy cell leukemia. The blood smear can suggest these factitious events and should be used to confirm the platelet count. It is important to validate the automated platelet count even when reported values are within the normal range, since electronic counting may result in a spurious thrombocytosis or a spuriously normal count.

Transbronchial lung biopsy in the diagnosis of lymphangitic carcinomatosis

The clinical diagnosis of lymphangitic carcinomatosis of the lung has generally been confirmed by open lung or transthoracic needle biopsy, precedures with significant morbidity and mortality, particularly in patients with respiratory insufficiency. We present six cases of lymphangitic carcinomatosis diagnosed by transbronchial biopsy. Autopsy confirmation was obtained in 4 patients and ultrastructural confirmation of intralymphatic location of tumor in one. The diffuse bronchial and peribronchial lymphatic involvement demonstrated here suggests that this relatively noninvasive technique should be the procedure of choice in the diagnosis of lymphangitic carcinomatosis of the lung.

Leiomyosarcoma metastatic to the brain

A rare instance of leiomyosarcoma metastatic to the brain in a 60-year-old male is presented. The primary site was in the gastrointestinal tract. Previously reported cases of similar nature are reviewed.

The endoscopic intrahepatic cholangiogram. Clinicopathologic correlation with postmortem cholangiograms

Endoscopic retrograde cholangiography (ERC) allows visualization of the entire biliary tree. The cholangiographic appearance of the intrahepatic bile ducts has received relatively little attention. This postmortem study was performed to define cholangiographic alterations produced by disease and to aid in the recognition of pathologic intrahepatic cholangiographic patterns produced by ERC. Intrahepatic cholangiographic patterns in the normal biliary tree, hepatic cirrhosis, hepatic infiltrative processes, and hepatic mass lesions are presented.