Janusz J. Godyn

A dual block to cell cycle progression in HL60 cells exposed to analogues of vitamin D

Abstract. The physiologically active form of vitamin D3, 1,25‐dihydroxy‐vitamin D3, (1,25(OH)2, D3), induces differentiation of several types of myeloid leukaemia cells. The acquisition of monocyte‐like phenotype is accompanied by slower progression through the cell cycle, and G1, block has been reported to be the basis of this effect. It is shown here that human promyelocytic leukaemia HL60 cells treated with analogues of vitamin D3, which are potent inducers of monocytic differentiation, have an additional cell cycle block. Exposure to 10‐7m 1,25(OH)2, D3, or 1,25‐(OH)2,‐16‐ene‐D3 resulted in monocytic differentiation and the expected G1, block evident at approximately 48 h in a rapidly differentiating variant of HL60 cells (HL60‐G), and at 96 h in the more slowly differentiating HL60‐240 cells. In addition, a G2,+M block was noted at approximately 72 h in HL60‐G and HL60‐240 cells. Exposure to vitamin D3, analogues also markedly increased the number of dikaryons, suggesting that cytokinesis was impaired more than karyokinesis. Treatment with a third analogue 25‐hydroxy‐16,23‐diene‐D3, produced little differentiation and had minimal effects on the cell cycle parameters. These findings indicate that vitamin D3, analogues regulate cell proliferation by control of the transition of G1, and G2,+M phases, reminiscent of the cdc2/CDK2 type of cell cycle control.

Monocytic differentiation of HL60 cells induced by potent analogs of vitamin D3 precedes the G1/G0 phase cell cycle block

Abstract. Differentiation of mammalian cells is accompanied by reduced rates of proliferation and an exit from the cell cycle. Human leukemic cells HL60 present a widely used model of neoplastic cell differentiation, and acquire the monocytic phenotype when exposed to analogs of vitamin D3 (VD3). The maturation process is accompanied by two blocks in the cell cycle: an arrest in the G1/G0 phase, and a recently described G2+ M block. In this study we have analyzed the traverse of the cell cycle phases of the well‐differentiating HL60‐G cells exposed to one of ten analogs of VD3, and compared the cell cycle effects of each compound with its potency as a differentiation‐inducing agent. We found that in general there was a good correlation between the effects of these compounds on the cell cycle and on differentiation, but the best cell cycle predictor of differentiation potency was the extent of accumulation of the cells in the G2 compartment. All analogs induced a marked decrease in the mitotic index, and polynucleation of HL60 cells was produced, especially by compounds which were effective as inducers of differentiation. Time course studies showed that induction of differentiation was accompanied by a transient increase of the proportion of cells in the G2+ M compartment, but preceded the G1 to S, and the G2 compartment blocks. These studies indicate that complex changes in the cell cycle traverse accompany, but do not precede, the acquisition of the monocytic phenotype by HL60 cells.

Increased stringency of the 1,25-dihydroxyvitamin D3-induced G1 to S phase block in polyploid HL60 cells

Treatment of mammalian cells with 1,25‐dihydroxyvitamin D3 (1,25D3) produces a G1 to S (G1/S) phase cell cycle block. In addition, it has been noted that a smaller proportion of cells accumulates in the G2/M compartment in 1,25D3‐treated cultures. Since cyclins have a major influence on the regulation of cell cycle progression, we determined the expression of cyclins A and B as markers of the G2 phase and of cyclin E as the marker of G1/S transition. No increase in the steady‐state levels of cyclin A or cyclin B mRNA was detected in the total cell population or in the cyclin B1 protein in the G2/M cell cycle compartment. In contrast, immunodetectable cyclin E protein was increased in cell cultures as a whole and specifically in the G2/M compartment cells. Determination of BrdU incorporation into DNA by flow cytometry showed marked inhibition of DNA replication in cells with DNA content higher than 4C, and autoradiography of 3H‐TdR‐pulsed cells showed that polynucleated cells did not replicate DNA after 96 h of treatment with 1,25D3 or analogs. Taken together, these experiments show that at least a portion of the G2/M compartment in 1,25D3‐arrested cultures of HL60 cells represents G1 cells at a higher ploidy level, which are blocked from entering the high ploidy S phase.

Cutaneous anthrax: conservative or surgical treatment?

This article summarizes the diagnostic features and treatment recommendations for cutaneous anthrax, exemplified by a case report of nontypical cutaneous anthrax. The treatment of choice is medical, with ciprofloxacin or doxycycline the preferred antibiotics. However, surgical biopsy may be used if the clinical setting and microbiologic examination of swabs are not diagnostically conclusive. Histopathologic findings explain the clinical observation that most cutaneous anthrax lesions heal without scar formation.

Schistosoma mansoni in Colon and Liver

Schistosoma mansoni is the species of the superfamily Schistosomatoidea that is pathogenic to humans. It is found in many countries in Africa and the Arabian Peninsula, as well as in the Western Hemisphere, including the islands of the West Indies and parts of Brazil. Its life cycle alternates between asexual multiplication in aquatic snails and sexual reproduction in humans. The life cycle of the major Schistosoma species has been described previously. 1 Cercariae infect humans through skin penetration in snail-infected waters. The parasites then migrate to the lungs and liver as schistosomula. They mature (female size, 1.6 cm) and mate in approximately 6 weeks. The adult worms are free of host reaction. Their habitat is portal venous, primarily of the large intestine, and egg deposition is hepatic and colonic. The eggs are elongated, with a prominent lateral spine near the more rounded posterior end, and measure up to 180 3 70 mm. They have a propensity to invade the venous walls and to penetrate the adjacent stroma. The eggs elicit the host reaction, which consists of suppurative inflammation and all stages of granulomas. Some eggs are excreted and are capable of hatching in water and infecting the snail intermediate host. Other eggs are trapped in the host tissue, where they die and disintegrate. Dead eggs usually are surrounded by resolving or scarred foci. Schistosoma mansoni eggs do not calcify. Inflammatory reaction can cause symptoms related to impairment of any organ in which the eggs are deposited, producing significant scarring. Therefore, an early diagnosis and prompt treatment are important. The diagnosis is based on the presence of eggs in feces (possibly using concentration methods to detect them) and in colonic biopsy specimens. 2 The images of eggs surrounded by inflammatory reaction in the colonic mucosa and the liver illustrate our case and correlate with clinical symptoms. A 25-year-old woman presented with a multiyear history of diarrhea. On examination, anemia, elevated liver enzymes, and gastrointestinal bleeding were found. She underwent elective colonoscopy, which revealed friable, erosive, and granular mucosa of the distal colon. Microscopic examination showed colonic mucosa with generally preserved crypt architecture, moderate inflammatory infiltrate of mucosal stroma, and multiple viable and nonviable parasitic eggs scattered in the mucosal stroma. Some areas with distorted crypt architecture and intraluminal leukocytes were noted, usually next to disintegrating eggs; however, no significant increase of intraepithelial leukocytes was seen

Retroperitoneal cystic abdominal lymphangiomatosis diagnosed by fine needle aspiration: a case report.

BACKGROUND Attributed to congenital malformation of lymphatic ducts, diffuse retroperitoneal cystic abdominal lymphangiomatosis has a distribution that often corresponds to the location of primitive fetal lymphatic sacs. Three recognized types are capillary, cavernous and cystic. Multisystem involvement may occur involving spleen, liver, bone, pancreas, soft tissue, limbs and brain. CASE A 55-year-old, healthy male with multiple liver lesions and retroperitoneal lymphadenopathy presented for retroperitoneal fine needle aspiration, producing 20 mL of milky liquid. Immediate cytologic evaluation showed a heterologous population of mature lymphocytes with chylomicrons. Flow cytometry revealed a polyclonal population of mature lymphocytes. Chemical analysis demonstrated a normal serum cholesterol level and an elevated triglyceride level. Serum markers were noncontributory. We review the differential diagnostic considerations leading to obstruction or retention of lymphatic fluids (malignancy, surgical, infective and traumatic), with an emphasis on the importance of onsite cytologic evaluation, correlation with clinical history and review of the etiologic considerations. CONCLUSION The constellation of clinical, radiologic, cytologic and laboratory findings presented in this paper are diagnostic of diffuse retroperitoneal cystic abdominal lynmphangiomatosis. To our knowledge, this entity has not been reported before in the fine needle aspiration literature. To prevent further disruption of lymphatic drainage, no further surgical sampling is planned.

Preparation and use of a scabies skin scraping kit.

A scabies outbreak could potentially occur in any health care facility at any time. Health care providers need to understand the proper steps to take in handling a suspected scabies case to keep this highly contagious infection under control. Because determining whether a rash is scabies, transporting the patient to a facility that can perform a skin scraping, or simply locating the appropriate materials for a skin scraping can be time consuming, prepared scabies skin scraping kits have been developed at the authors’ facility; an educational program has been made available as well. This article discusses and illustrates the facility’s method of skin scraping and describes the supplies included in a prepared scabies skin scraping kit. The prepared kits are available to nursing units, emergency departments, outpatient services, clinics, and nursing homes throughout the hospital network. An educational presentation that includes video segments of the procedure is also accessible via the Internet. The combination of these factors has had a positive impact on the practice of skin scraping within the authors’ hospital network.