Cytotoxic and proapoptotic effect of doxycycline - An in vitro study on the human skin melanoma cells

Doxycycline is a semisynthetic, second generation tetracycline. Currently, it is used, among others, in the treatment of acne and skin infections. Moreover, doxycycline has many valuable nonantibiotic properties, including anti-inflammatory, immunosuppressive and anticancer effects. Recent studies showed that the drug had the ability to inhibit the adhesion and migration of cancer cells, as well as affected their growth and proliferation and induced apoptosis. The purpose of this study was to examine the antimelanoma effect of doxycycline. The obtained results demonstrated that doxycycline decreased the viability and inhibited the proliferation of human melanoma cells, proportionally to the drug concentration and the treatment time. It was stated that doxycycline disturbed the homeostasis of the cells by lowering intracellular level of reduced thiols. In addition, the treatment changed the cell cycle profile and triggered the DNA fragmentation. Mitochondria of melanoma cells exposed to the drug had lowered membrane potential, which indicated cells apoptosis. Finally, doxycycline induced the externalization phosphatidylserine - a well-known hallmark of apoptosis, confirmed by results of annexin V test. The presented study contributes to the increase of knowledge about nonantibacterial action of doxycycline, including the influence on human cancer cells and indicates new potential possibility of effective treatment of malignant melanoma.

MIM1 induces COLO829 melanoma cell death through mitochondrial membrane breakdown, GSH depletion, and DNA damage

Malignant melanoma is a high aggressive malignancy in humans and causes 60-80% of deaths from skin cancer. Defect in an intrinsic pathway of apoptosis via overexpression of Mcl-1 is responsible for malignant melanoma development and progression, and also for resistance to chemotherapeutic agents. MIM1 is a specific low molecular Mcl-1 protein inhibitor that is able to induce Mcl-1-dependent cancer cells death. Here, we examined the effect of MIM1 as well as MIM1 and dacarbazine (DTIC) mixture on cell viability, apoptosis, and cell cycle progression in COLO829 melanoma cells. Cell viability was performed by the WST-1 assay. Analysis of apoptosis as well as cell cycle progression was determined by fluorescence image cytometer NucleoCounter NC-3000. The obtained results demonstrated that the MIM1 exhibited high cytotoxicity against melanotic melanoma cells and induced mitochondrial membrane breakdown, GSH depletion, and DNA fragmentation. Additionally, MIM1 enhanced the proapoptotic effect of DTIC toward melanoma cells; furthermore, a mixture of these drugs caused cell cycle arrest at G2/M phase in COLO829 cells. Taken together, these data provide, for the first time, evidence that a low molecular weight Mcl-1 inhibitor-MIM1 may be a promising agent with antitumor and proapoptotic properties toward melanoma cells.

Mcl-1 Inhibitor Induces Cells Death in BRAF-Mutant Amelanotic Melanoma Trough GSH Depletion, DNA Damage and Cell Cycle Changes

Mcl-1 is a potent antiapoptotic protein and amplifies frequently in many human cancer. Currently, it is considered that the extensively expressed of Mcl-1 protein in melanoma cells is associated with rapid tumor progression, poor prognosis and low chemosensitivity. Therefore, the antiapoptotic protein Mcl-1 could be considered as a potential target for malignant melanoma treatment. The aim of this study was to assess the effect of MIM1 a specific low molecular Mcl-1 protein inhibitor and mixture of MIM1 and dacarbazine on the viability, cell cycle progression and apoptosis induction in amelanotic C32 melanoma cells. The cytotoxic activity of MIM1 towards C32 melanoma cells was examined by the WST-1 test. The Mcl-1 protein level as a drug target in amelanotic melanoma cells was defined by Western blot analysis. Cell cycle progression, DNA fragmentation as well as GSH depletion were determined by fluorescence image cytometer NucleoCounter NC-3000. The obtained results demonstrate that the specific Mcl-1 protein inhibitor - MIM1 decreases cell viability and induce apoptosis (S-phase arrest, DNA fragmentation and redox imbalance) in amelanotic melanoma cells and intensify the proapoptotic properties of DTIC, as a result of interactions with Mcl-1 protein. Taken together, the presented data suggest that Mcl-1 protein is a an important target in malignant melanoma treatment and provide for the first time convincing evidence that MIM1, which inhibits Mcl-1 antiapoptotic protein is able to induce apoptosis and sensitize melanoma cells to alkylating agent.

Chlortetracycline and melanin biopolymer - The risk of accumulation and implications for phototoxicity: An in vitro study on normal human melanocytes

Tetracyclines belong to antimicrobial classes with the highest consumption in veterinary medicine and agriculture, which leads to the contamination of the environment and food products, as well as to antibiotic resistance and adverse drug reactions. Chloro-derivatives of tetracyclines are thought to be relatively more phototoxic than others and belong to the most frequently cited drugs as photosensitizers. Melanins are heterogenous biopolymers determining skin, hair and eye colour. They are biosynthesized in a multistep process in melanocytes. Melanins, besides photoprotective and antioxidant properties, may also contribute to adverse skin drug reactions, which involve e.g. hyperpigmentation disorders and phototoxic reactions. Furthermore, they have the ability to form a drug-melanin complex, which leads to deposition of the drug or its metabolites in pigmented tissues. The aim of the study was to examine the ability of chlortetracycline to form a complex with melanin, as well as the effect of the drug on viability, antioxidant defence system and melanogenesis in normal human epidermal melanocytes exposed to the UVA radiation. The obtained results show for the first time that chlortetracycline forms a complex with melanin polymers, which creates a possibility of the drug accumulation in pigmented tissues. A simultaneous exposition of normal melanocytes to chlortetracycline and to the UVA radiation decreases cell viability, proportionally to the drug concentration and the irradiation time. The phototoxic effect appears to be related to the induction of oxidative stress in melanocytes, mainly through an increase of SOD and a decrease of the CAT activity. Chlortetracycline itself does not influence the melanin content or the activity of tyrosinase. The UVA radiation appeared to be a conditioning factor stimulating melanogenesis, whereas the presence of the drug augmented this effect.

Kanamycin induces free radicals formation in melanocytes: An important factor for aminoglycosides ototoxicity

Ototoxicity is well-documented but not fully understood undesirable side effect of aminoglycoside antibiotic, kanamycin. Kanamycin is capable of binding to melanin biopolymers-natural pigments of the skin, hair, and eyes. Melanin-producing cells, melanocytes, are also present in the inner ear and are known to be necessary for normal hearing. It was considered that melanin content in the inner ear may influence aminoglycoside-induced ototoxic effect. The impact of kanamycin on melanocytes homeostasis may thus play role in the antibiotic-induced ototoxic effect. Previously, we demonstrated that kanamycin disturbs homeostasis in light-pigmented melanocytes. To investigate if/how melanization contributes to this phenomenon, the study using in vitro model of dark-pigmented melanocytes is required. Spectrophotometric measurements and electron paramagnetic resonance (EPR) spectroscopy analysis were performed. Kanamycin induced a concentration-dependent loss in HEMn-DP melanocytes viability. The value of IC ₅₀ was estimated to be 5.0 mM. Modulation of the activity of analyzed antioxidant enzymes and increased production of free radicals as well as the decrease of the melanin content were observed. Our results confirmed that kanamycin generates oxidative stress in melanocytes. The increased level of free radicals caused by kanamycin may be responsible for the imbalance of antioxidant defense and the reduction of melanin content in melanocytes. The role of melanin in the mechanism of kanamycin-induced hearing impairment was discussed and the obtained results were compared with the previously demonstrated data concerning light-pigmented melanocytes.

Vitamin B12 Deficiency Induces Imbalance in Melanocytes Homeostasis-A Cellular Basis of Hypocobalaminemia Pigmentary Manifestations

Vitamin B₁₂ deficiency causes significant changes in cellular metabolism leading to various clinical symptoms, such as hematological, psychiatric, and neurological disorders. We hypothesize that skin pigmentation disorders may be a diagnostically important manifestation of vitamin B₁₂ deficiency, however the cellular and molecular mechanisms underlying these effects remain unknown. The aim of this study was to examine the effect of vitamin B₁₂ deficiency on melanocytes homeostasis. Hypocobalaminemia in vitro model was developed by treating epidermal melanocytes with synthesized vitamin B₁₂ antagonist—hydroxycobalamin(c-lactam). The cells were examined using immunoenzymatic, spectrophotometric, and fluorimetric assays as well as image cytometry. Significant melanogenesis stimulation—the increase of relative melanin content and tyrosinase activity up to 131% and 135%, respectively—has been indicated. Cobalamin-deficient cells displayed the elevation (by 120%) in reactive oxygen species level. Moreover, the redox status imbalance was stated. The study provided a scientific evidence for melanocytes homeostasis disturbance under hypocobalaminemia, thus indicating a significant element of the hyperpigmentation mechanism due to vitamin B₁₂ deficiency. Furthermore, the implication between pigmentary and hematological and/or neuropsychiatric symptoms in cobalamin-deficient patients may be an important issue.

MIM1, the Mcl-1 - specific BH3 mimetic induces apoptosis in human U87MG glioblastoma cells

Glioblastoma multiforme (GBM) is the most common and high aggressive malignant brain tumor. Despite evolving oncology treatment and novel chemotherapeutic agents the median survival of patients diagnosed with GBM is only 12-15 months. This grim fact highlights necessity to identify new drugs that could improve the effectiveness of GBM patients treatment. MIM1 is a specific low molecular Mcl-1 protein inhibitor able to induce Mcl-1-dependent cancer cells death. The aim of this study was to examine the effect of MIM1 as well as MIM1 and temozolomide (TMZ) mixture on cell viability, apoptosis and cell cycle progression in human U87MG glioblastoma cells. Cell viability was performed by the WST-1 assay. Mitochondrial membrane potential, Annexin V assay, DNA fragmentation and cell cycle distribution were determined by fluorescence image cytometer NucleoCounter NC-3000. The obtained results show that MIM1 and MIM1/TMZ mixture decrease glioblastoma cells viability in a dose- and time- dependent manner. Moreover, the exposure of U87MG cells to MIM1 and MIM1/TMZ mixture causes mitochondrial dysfunction as well as DNA fragmentation and cell cycle arrest at G₂/M phase. This study provides for the first time convincing evidence that BH3 mimetic MIM1, which inhibits Mcl-1 antiapoptotic protein may be an efficacious molecule able to induction of apoptosis and sensitize GBM cells to alkylating agents.

GSH depletion, mitochondrial membrane breakdown, caspase-3/7 activation and DNA fragmentation in U87MG glioblastoma cells: New insight into the mechanism of cytotoxicity induced by fluoroquinolones

Fluoroquinolones are a known synthetic group of antibiotics that have been the subject of many research interests. This class of antibiotics was shown to be cytotoxic towards various cancer cell lines, thus representing a potentially important source of new anticancer agents. The present study was designed to examine the effect of ciprofloxacin and moxifloxacin on cell viability, redox balance and apoptosis in U87MG glioblastoma cells. Herein, we found that both fluoroquinolones decrease the viability and exert an anti-proliferative effect on U87MG cells. The EC₅₀ values were found to be as 0.75 µmol/ml, 0.57 µmol/ml, 0.53 µmol/ml for ciprofloxacin and 24, 48, 72 h incubation time, respectively, and 0.48 µmol/ml, 0.22 µmol/ml, 0.15 µmol/ml for moxifloxacin and 24, 48, 72 h incubation time, respectively. Ciprofloxacin and moxifloxacin have also induced the intracellular GSH depletion and apoptosis as shown by externalization of phosphatidylserine, caspase-3/7 activation, S and sub-G₁ cell cycle arrest, nuclear morphological changes induction and DNA fragmentation. The mechanism of apoptosis was related to the loss of mitochondrial membrane potential suggesting activation of the intrinsic mitochondrial pathway. This is the first study that may provide the basis for understanding potential cellular and molecular mechanism underlying ciprofloxacin and moxifloxacin cytotoxic and pro-apoptotic effect towards U87MG glioblastoma cells, suggesting that these fluoroquinolone derivatives may have value for the development as anti-glioma agents.

Caffeine modulates growth and vitality of human melanotic COLO829 and amelanotic C32 melanoma cells: Preliminary findings

Coffee is one of the most popular beverages consumed worldwide and therefore even small effects of coffee bioactive compounds on cellular homeostasis could have a large impact on public health. Recent cohort health studies have shown an impressive inverse correlation between caffeinated coffee consumption and malignant melanoma risk. The aim of presented study was to examine the effect of caffeine on cell viability and glutathione status of melanotic (COLO829) and amelanotic (C32) melanoma cell lines as well as normal human melanocytes. Cell viability was determined by WST-1 colorimetric assay and then confirmed by the cytometry analysis with NucleoCounter^® NC-3000™. The intracellular level of reduced thiols was determined by the use of the fluorescence-based image cytometer. The obtained results indicate the ability of caffeine to induce reduced thiols depletion and pro-apoptotic effect selectively in melanoma cells. The COLO829 cell line was shown to be more susceptible to studied methylxanthine in comparison to C32 cells. These data may support, for the first time, the recent epidemiological studies and provide the basis for further research into the mechanism of chemopreventive properties of caffeine.

Ciprofloxacin triggers the apoptosis of human triple-negative breast cancer MDA-MB-231 cells via the p53/Bax/Bcl-2 signaling pathway

Fluoroquinolone antibiotics induce cytotoxicity in various cancer cell lines and may therefore represent a potentially important source of novel anticancer agents. The aim of the present study was to examine the effect of ciprofloxacin on the viability, redox balance, apoptosis, expression of p53, Bax and Bcl-2, cell cycle distribution and DNA fragmentation of triple-negative MDA-MB-231 breast cancer cells. The results of the present study demonstrated that ciprofloxacin decreases cell viability in a dose- and time-dependent manner. The half maximal inhibitory concentration values of ciprofloxacin in MDA-MB-231 cells following treatment for 24, 48 and 72 h were 0.83, 0.14 and 0.03 µmol/ml, respectively. Furthermore, it was demonstrated that ciprofloxacin altered the redox signaling pathway, as determined by intracellular glutathione depletion. The results of Annexin V/propidium iodide staining revealed that ciprofloxacin triggered the apoptosis of MDA-MB-231 cells. Furthermore, cipfloxacin treatment stimulated the loss of the mitochondrial transmembrane potential via the Bax/Bcl-2-dependent pathway, thus inducing apoptosis. Ciprofloxacin induced cell cycle arrest at the S-phase; therefore it was hypothesized that ciprofloxacin inhibits topoisomerase II. Oligonucleosomal DNA fragmentation and the elevation of p53 expression were observed in the present study, indicating that this late-apoptotic event may be mediated by the p53-dependent pathway. Therefore, the results of the current study provide important molecular data concerning the cellular cascade, which may explain the cytotoxicity induced by ciprofloxacin in human triple-negative breast cancer cells, thus providing a novel insight into the therapeutic properties of this drug.

Effect of fluoroquinolones on melanogenesis in normal human melanocytes HEMn-DP: a comparative in vitro study

PURPOSE

Fluoroquinolones are one of the most commonly prescribed classes of antibiotics. However, their use is often connected with high risk of phototoxic reactions that lead to various skin or eye disorders. The aim of this study was to examine the effect of ciprofloxacin, lomefloxacin, moxifloxacin and fluoroquinolone derivatives with different phototoxic potential, on the viability and melanogenesis in melanocytes.

MATERIALS AND METHODS

Normal human epidermal melanocytes, dark pigmented (HEMn-DP) were used as an in vitro model system. The effect of the tested antibiotics on cell viability and melanization in pigmented cells was investigated using a spectrophotometric method. The WST-1 assay was used to detect the cytotoxic effect of antibiotics.

RESULTS

Ciprofloxacin, lomefloxacin and moxifloxacin induced the concentration-dependent loss in melanocytes viability. The values of EC₅₀ for the tested fluoroquinolone derivatives were found to be 2.0 mM for ciprofloxacin, 0.51 mM for lomefloxacin and 0.27 mM for moxifloxacin. The exposure of cells to different concentrations of the analyzed drugs resulted in decrease in melanin content and tyrosinase activity. The highest decrease was observed for lomefloxacin which may explain its high phototoxic potential in vivo. The role of melanin in the mechanism of the toxicity of fluoroquinolones was discussed and the obtained results were compared with the previously obtained data concerning light-pigmented melanocytes (HEMa-LP).

CONCLUSIONS

The results obtained in vitro suggest that the phototoxic potential of fluoroquinolones in vivo depends on specific drug-melanin interaction, the ability of drugs to affect melanogenesis as well as on the degree of melanocytes pigmentation.

[Regulation of neurogenesis: factors affecting of new neurons formation in adult mammals brain]

Neurogenesis is a complex and multi-step process of generating completely functional neurons. This process in adult brain is based on pluripotentional neuronal stem cells (NSC), which are able to proliferation and differentiation into mature neurons or glial cells. NSC are located in subgranular zone inside hippocampus and in subventricular zone. The new neurons formation depends on many endo- and exogenous factors which modulate each step of neurogenesis. This article describes the most important regulators of adult neurogenesis, mainly: neurotrophins, growth factors, hormones, neurotransmitters and microenvironment of NSC. Some drugs, especially antipsychotics, antidepressants and normothymics may affect the neurogenic properties of adult brain. Moreover pathological processes such as neuroinflammation, stroke or epilepsy are able to induce proliferation of NSC. The proneurogenic effects of psychotropic drugs and pathological processes are associated with their ability to increase some hormones and neurotrophins level, as well as with rising the expression of antiapoptotic Bcl-2 protein and metalloproteinase MMP-2. Additionaly, some drugs, for example haloperidol, are able to block prolactin and dopaminergic neuroblasts receptors. Down-regulation of adult neurogenesis is associated with alcohol abuse and high stress level. Negative effect of many drugs, such as cytostatics, COX-2 inhibitors and opioides was also observed. The proneurogenic effect of described factors suggest their broad therapeutic potential and gives a new perspective on an effective and modern treatment of many neuropsychiatric disorders. This effect can also help to clarify the pathogenesis of disorders associated with proliferation and degeneration of adult brain cells.

[Lympho-venous shunts and thromboids in urinary obstruction]

This case of urinary obstruction with short anamnesis illuminates the early tissue reaction to urine extravasation, especially the Tamm-Horsfall protein. The latter becomes organized in the manner of a foreign body substance and drains via ectatic renal lymph vessels and reopened lymphovenous shunts into the intrarenal venous system. Polypoid formations (thromboids) with or without vessel obliteration appear to result in a clinical course of severe renal impairment.

[Acute generalized cat scratch disease in myelodysplastic syndrome]

In patients with normal immunity, cat scratch disease typically develop a papule at the portal of entry and no other cutaneous features. A 73 year old male patient with a myelodysplastic syndrome developed generalized petechial, papular and, vasculitic skin lesions in association with cat scratch disease. After the diagnosis was established by identifying the causative organism in a lymph node biopsy, the patient was treated with erythromycin for three weeks resulting in progressive clearance of the skin lesions. Apart from the soluble IL-2 receptor, no other serologic inflammatory parameters were elevated. IgG antibodies against Bartonella henselae and Bartonella quintana increased only slightly during acute exacerbation of the disease, but significantly increased some months later. The diagnosis was established by the positive staining of the lymph node biopsy using the Warthin-Starry stain.

Selective cyclo-oxygenase-2 inhibitors aggravate ischaemia-reperfusion injury in the rat stomach

1. Effects of indomethacin, the selective cyclo-oxygenase (COX)-2 inhibitors NS-398 and DFU, and dexamethasone on gastric damage induced by 30 min ischaemia followed by 60 min reperfusion (I-R) were investigated in rats. Modulation of gastric levels of COX-1 and COX-2 mRNA by I-R was evaluated using Northern blot and reverse transcription-polymerase chain reaction. 2. I-R-induced gastric damage was dose-dependently aggravated by administration of indomethacin (1 - 10 mg kg(-1)), NS-398 (0.4 - 4 mg kg(-1)) or DFU (0.02 - 2 mg kg(-1)) as assessed macroscopically and histologically. 3. Likewise, administration of dexamethasone (1 mg kg(-1)) significantly increased I-R damage. 4. Low doses of 16, 16-dimethyl-prostaglandin(PG)E(2), that did not protect against ethanol-induced mucosal damage, reversed the effects of the selective COX-2 inhibitors, indomethacin and dexamethasone. 5. I-R had no effect on gastric COX-1 mRNA levels but increased COX-2 mRNA levels in a time-dependent manner. Dexamethasone inhibited the I-R-induced expression of COX-2 mRNA. 6. I-R was not associated with a measurable increase in gastric mucosal formation of 6-keto-PGF(1alpha) and PGE(2). PG formation was substantially inhibited by indomethacin (10 mg kg(-1)) but was not significantly reduced by NS-398 (4 mg kg(-1)), DFU (2 mg kg(-1)) or dexamethasone (1 mg kg(-1)). 7. The findings indicate that selective COX-2 inhibitors and dexamethasone markedly enhance gastric damage induced by I-R. Thus, whereas COX-2 has no essential role in the maintenance of gastric mucosal integrity under basal conditions, COX-2 is rapidly induced in a pro-ulcerogenic setting and contributes to mucosal defence by minimizing injury. This suggests that in certain situations selective COX-2 inhibitors may have gastrotoxic effects.

Peptidergic and cholinergic neurons and mediators in peptone-induced gastroprotection: role of cyclooxygenase-2

This study investigates the neural pathways, mediators, and cyclooxygenase isoenzymes involved in the gastroprotection conferred by peptone in rats. Intragastric perfusion with 8% peptone protected against gross and histological damage induced by subsequent perfusion with 50% ethanol. The gastroprotective effect of peptone was near maximally inhibited by gastrin immunoneutralization, inactivation of capsaicin-sensitive afferent neurons, calcitonin gene-related peptide (CGRP) immunoneutralization, blockade of gastrin receptors, CGRP, bombesin/gastrin-releasing peptide (GRP), or somatostatin receptors, and by the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester and was partially (46%) counteracted by atropine. Indomethacin and the selective cyclooxygenase-2 inhibitors NS-398 and L-745,337 dose dependently (50% inhibitory dose, 4.2, 0.8, and 1.5 mg/kg, respectively) attenuated the peptone-induced protection. Dexamethasone was ineffective. These results indicate that protective effects of peptone involve endogenous gastrin and possibly somatostatin and are mediated by capsaicin-sensitive afferent, cholinergic, and bombesin/GRP neurons. CGRP, NO, and prostaglandins participate as essential mediators. The study provides evidence that prostaglandins derived from a constitutive cyclooxygenase-2 contribute to mucosal defense in the presence of ulcerogens and thus participate in homeostatic functions of the stomach.

Selective cyclo-oxygenase-2 inhibitors and their influence on the protective effect of a mild irritant in the rat stomach

1. The effects of the non-selective cyclo-oxygenase (COX) inhibitor indomethacin and the selective COX-2 inhibitors, N-[2-(cyclohexyloxy)-4-nitrophenyl] methanesulphonamide (NS-398), 5-methanesulphonamido-6-(2,4-difluorothio-phenyl)-1-indan one (L-745,337) and 5,5-dimethyl-3-(3-fluorophenyl)-4-(4-methylsulphonyl) phenyl-2(5H)-furanone (DFU), on the protection induced by the mild irritant 20% ethanol were investigated in the rat stomach. 2. Instillation of 20% ethanol (1 ml, p.o.) effectively protected against gastric mucosal injury induced by subsequent instillation of 70% or 96% ethanol (1 ml, p.o.). 3. Oral administration of indomethacin (1.25-20 mg kg[-1]) dose-dependently counteracted the protective effect of 20% ethanol (ID50: 3.5 mg kg[-1]). 4. Likewise, NS-398 (0.1-1 mg kg[-1]), L-745,337 (0.2-2 mg kg[-1]) and DFU (0.02-0.2 mg kg[-1]) inhibited the protective effect of 20% ethanol in a dose-dependent manner with ID50 values of 0.3 mg kg(-1), 0.4 mg kg(-1) and 0.06 mg kg(-1), respectively. 5. Inhibition of mild irritant-induced protection was also found when NS-398 (1 mg kg[-1]) was administered s.c. or when 96% ethanol was used to damage the mucosa. 6. Pretreatment with 16,16-dimethyl-prostaglandin (PG)E2 at 4 ng kg(-1), a dose that did not protect against ethanol (70%)-induced mucosal damage when given alone, completely reversed the effect of the selective COX-2 inhibitors on the mild irritant-induced protection. 7. Pretreatment with dexamethasone (3 mg kg(-1), 24 and 2 h before instillation of 20% ethanol) did not affect the protective activity of the mild irritant, indicating that enzyme induction is not involved. 8. Indomethacin (20 mg kg(-1), p.o.) did not prevent the protection conferred by sodium salicylate (100 mg kg[-1]), dimercaprol (30 microg kg[-1]), iodoacetamide (50 mg kg[-1]) and lithium (20 mg kg[-1]). Likewise, the protective effect of these agents was not counteracted by NS-398 (1 mg kg(-1), p.o.). 9. Whereas indomethacin (20 mg kg(-1), p.o.) near-maximally inhibited gastric mucosal formation of PGE2, 6-keto-PGF1alpha and thromboxane (TX) B2 as well as platelet TXB2 release, the selective COX-2 inhibitors were ineffective. 10. The findings show that selective COX-2 inhibitors, although lacking in ulcerogenic activity, prevent the protection conferred by a mild irritant. Prostaglandis generated by a constitutive COX-2 could thus contribute to physiological functions involved in gastric homeostasis, although at present a non-COX-2-related mechanism underlying the effect of the selective COX-2 inhibitors tested on mild irritant-induced protection cannot be completely excluded.

Parvovirus particles in a fetal-heart with myocarditis: ultrastructural and immunohistochemical study

We report on the occurrence of parvovirus particles and VP1 (84 kDa) and VP2 (58 kDa) viral antigens in the heart of a case of fatal myocarditis in a fetus of a 26 year old women. Numerous cells containing intranuclear inclusions were identified within the blood vessels of the heart in a close apposition to muscle fibers. These cells were characterized by plentiful mitochondria and were consistent with erythroblasts. Typically, inclusions consisted of electrondense marginated chromatin and granular and amorphous "cores". At higher magnification, parvovirus particles, approximately 23 nm in diameter, were visualized either as relatively small clusters or forming large paracrystalline arrays. Virus buds were never observed. In addition, unusual membrane proliferation was seen. These findings support a notion that parvovirus may invade the fetal heart.

Diagnostic and perinatal management of fetal extrasystole

Fifty fetuses referred to the Polish Mother's Memorial Hospital for fetal echocardiography between January 1, 1991 and June 1, 1995 were evaluated. The mean fetal gestational age at the time of diagnosis of arrhythmia was 34.1 weeks, and the mean gestational age at the time of delivery was 38.7 weeks. Checkup echocardiographic examinations were performed every 10-14 days, for a mean 2.4 studies per fetus. In most cases (48/50, 96%), premature atrial contractions were present during the first echocardiography examination. The fetal heart study was normal in 30 cases; in 7 (14%) there was tricuspid valve regurgitation, in 7 (14%) an atrial septal aneurysm, in 4 congenital heart defects, in 1 myocardial hypertrophy, and in 1 disproportion in the four-chamber view. Of the 50 fetuses, 43 underwent regular echocardiographic monitoring alone; in 7 cases, based on the presence of additional echocardiographic findings, pharmacotherapy was applied (digoxin, verapamil, or both). Three neonates died after delivery owing to malformations in two cases (one critical aortic stenosis, one spina bifida plus hygroma colli) and due to myocarditis in one case. In six of seven newborns treated in utero, myocarditis was diagnosed after birth (including the one with neonatal demise). Most of the newborns were in good condition after birth, their mean Apgar score being 8.6 and the mean birth weight 3259 g. We concluded that most extrasystoles represent an isolated anomaly, not affecting the fetal condition. Their presence should not influence the obstetric care and may require only echocardiographic monitoring. In most of our cases the premature contractions subsided after birth, although sometimes they preceded fetal supraventricular tachycardia or appeared after congenital myocarditis.

Reversal of diastolic flow in the middle cerebral artery of the fetus during the second half of pregnancy

This study obtained data on 22 fetuses in whom reversal of diastolic flow in the middle cerebral artery (MCA) was seen. In 59% of cases there was normal heart function and in 28% there was isolated tricuspid valve regurgitation. The majority (73%) of cases presented with normal fetal anatomy and most (82%) had a normal amniotic fluid index and normal fetal growth. In all cases, Doppler results of the umbilical artery and vein were normal. Of the women, 65% were on no medication and 73% did not smoke during pregnancy. The reversal of diastolic flow in the MCA was seen temporarily in the majority of cases (for 2-30 min); however, in one case with rhesus factor disease and a rim of ascites, it was observed for a longer period (about 2 h) and on the following day, intrauterine demise was recorded. In most of the cases without structural malformations, the neonatal outcome was normal. We conclude that reversed diastolic flow in the MCA is a rare and usually transient event. In one of our cases prolonged reversed flow preceded intrauterine demise. Therefore, this may be an ominous sign and careful fetal surveillance should be undertaken when this observation is made. There are a few possible pathomechanisms of reversed diastolic flow in the MCA. In the majority of cases the cause of the observed phenomenon remains unknown, but an increased pressure in the right ventricle and possible tricuspid regurgitation should be considered.

Fetal functional pulmonary atresia with ascites resolving spontaneously before birth. A case report

In this case we report functional pulmonary atresia in a fetus with significant tricuspid valve regurgitation and severe ascites, with spontaneous improvement without prenatal intervention and a subsequent follow-up at 8 weeks after birth.

Tachykinin-induced increase in gastric mucosal resistance: role of primary afferent neurons, CGRP, and NO

The tachykinins [Ala5,beta-Ala8]neurokinin A-(4-10) {[Ala5,beta-Ala8]NKA-(4-10)} and NKA-(4-10) dose dependently protected against ethanol-induced gastric mucosal damage in rats (half-maximal inhibitory dose, 46 and 48 nmol/kg, respectively). These effects were abolished by primary afferent nerve denervation, calcitonin gene-related peptide (CGRP) immunoneutralization, the CGRP receptor antagonist human (h) hCGRP-(8-37), and inhibition of nitric oxide (NO) biosynthesis by NG-nitro-L-arginine methyl ester. Tachykinin-induced protection occurred despite marked depression of gastric mucosal blood flow and was not associated with increased acid secretion. NK2-receptor blockade antagonized the protective effects of [Ala5,beta-Ala8]NKA-(4-10) and NKA-(4-10), whereas NK1-receptor blockade was ineffective. Blockade of NK2 but not NK1 receptors prevented by 65% the protection evoked by topical capsaicin without affecting capsaicin-induced hyperemia. We conclude that the increase in gastric mucosal resistance evoked by tachykinins is NK2 receptor-mediated and involves primary afferent neurons, CGRP, and NO. Gastric mucosal hyperemia and increased acid secretion do not participate in the effect. Tachykinins activating NK2 receptors contribute to the increase in gastric mucosal resistance but not the increment in mucosal blood flow after primary afferent nerve stimulation by capsaicin.

[Analysis of the questionnaire for prenatal ultrasonography in women delivering at the Polish Mother's Memorial Hospital in the year 1995]

After delivery at the Polish Mother's Memorial Hospital, Lódź Poland (PMMH), 1658 women were asked to fulfill the questionnaire regarding US studies during their pregnancy. At least one US study had 94% (1559) of pregnant women, 6% (99) had none. Three-US studies (the optimal number recommended by the authors) had 26%, 2-US studies had 33%, 1-US studies had 22%. Our data confirm that the series of 3-US studies during the low risk pregnancy, as it is recommended in most European countries needs further promotion and implementation in Poland. In our center, in the majority of cases, 4 or more US studies were performed in high risk pregnancies.

[Evaluation of the diagnostic usefulness for ultrasonographic and echocardiographic lethal markers in fetal pulmonary hypoplasia. Analysis of 11 cases]

Results of ultrasonographic and echocardiographic studies of 11 fetuses were analysed retrospectively in relation to their pulmonary hypoplasia. Congenital malformations, quality of hydramnios and echocardiographical measurements of fetal chest were estimated. The best symptoms of pulmonary hypoplasia were: oligo/ahydramnios, absence of fetal breathing movements and malformations in fetal chest cavity (diaphragmatic hernia, cardiomegaly, hydrothorax). Systemic malformations were present in each case. The measurements such as CC, CA, HA, (CA-HA) x 100/CA were not accurate enough and we did not find any statistical differences between the control and the studied group. Finding several factors predisposing to lung hypoplasia means that its lethal form may be present in fetus.

[Prenatal echocardiography of aortic stenosis]

Between 1991-1995 five cases of fetal critical aortic stenosis were diagnosed by fetal echocardiography at the Polish Mother's Memorial hospital. The main cause for referral for fetal ECHO was fetal ascites detected during routine obstetrical ultrasound scan in four cases and positive family history in one case. Pregnant women had fetal echocardiography monitoring as in-patients. During the first examination, the mean aortic valve size was 3.9 mm, mean shortening fraction of LV was 15.8%, mean heart/chest area ratio was 0.51. In one case pharmacological treatment with digoxin (due to fetal congestive heart failure) and steroids (to stimulate fetal lung maturity) was introduced. Amniocentesis due to severe polyhydramnios and fetal ascites drainage were also performed in this case. The were 2 fetal demises at 26 and 28 weeks of pregnancy, 3 cesarean section due to fetal distress during the first period of labour. The pH of umbilical blood was > 7.2. The newborns died between days 2-4 of life.

CONCLUSIONS

Aortic valve stenosis can be diagnosed prenatally. This type of fetal heart defect has a poor prognosis.

Fetal echocardiography guidelines to predict survival of fetuses with ascites

In a retrospective analysis of the standard protocols for fetal echocardiographic examination, 27 fetuses (mean gestational age 29 +/- 5.4 weeks) with ascites were evaluated. Fetal cardiomegaly (increased heart area/chest area ratio), the presence or absence of atrioventricular valve regurgitation, inferior vena cava and ductus venosus Doppler flow velocity and umbilical vein pulsation were evaluated quantitatively in a group of survivors and non-survivors. A statistically significant difference between the two groups was found for the presence of atrioventricular valve regurgitation (p = 0.003), and for cardiomegaly (p = 0.009). There was no statistical difference for the presence of abnormal venous flow and umbilical pulsation (p > 0.05). Abnormal venous Doppler flow velocities in the inferior vena cava and ductus venosus were observed more frequently than umbilical vein pulsation. The mean heart area/chest area ratios in the group of survivors and in the group of non-survivors were 0.34 +/- 0.09 and 0.48 +/- 0.08, respectively (p < 0.001). The mean gestational ages at the time of diagnosis of ascites in the groups of survivors and non-survivors were 33 +/- 3.3 weeks and 28 +/- 5.1 weeks, respectively (p < 0.05); the mean gestational ages at the time of delivery were 35.6 +/- 2.3 weeks and 33.3 +/- 4.9 weeks, respectively (p = 0.33). In terms of different echocardiographic features as well as the gestational age of the unborn patient with ascites, there is apparently no single indicator of a poor prognosis. Our results suggest that the prognosis is usually poor in a fetus with ascites, when cardiomegaly is detected, as well as the presence of tricuspid and mitral valve regurgitation. This is regardless of the type of venous flow and regardless of the etiology of the ascites.

Functional ablation of sensory neurons impairs healing of acute gastric mucosal damage in rats

Healing of ethanol-injured gastric mucosa was studied in rats treated with a neurotoxic dose of capsaicin to induce functional ablation of sensory nerves. Capsaicin treatment delayed the healing of mucosal damage in the glandular region and promoted the development of deep ulcerations predominantly in the antrum. These lesions occupied 86% of the antral surface and were associated with marked invasion of inflammatory cells and 18-fold elevation of gastric myeloperoxidase activity compared with vehicle-pretreated rats. Inhibition of cyclooxygenase, 5-lipoxygenase, or nitric oxide synthase did not affect the development of antral lesions after ethanol challenge in capsaicin-pretreated rats. In vehicle-pretreated rats, inhibition of nitric oxide synthase did not mimic the effect of functional ablation of sensory neurons. The findings suggest that in the gastric mucosa sensory neurons contribute to repair processes and limit the inflammatory response to injury. These effects do not involve arachidonic acid metabolites or nitric oxide.

Protection by gastrin in the rat stomach involves afferent neurons, calcitonin gene-related peptide, and nitric oxide

BACKGROUND & AIMS

Certain gut peptides exert gastroprotective effects. However, the underlying mechanism is not fully understood. This study examines the contribution of afferent neurons, calcitonin gene-related peptide, and nitric oxide to the protection conferred by gastrin 17 in the rat stomach.

METHODS

Gastroprotection by gastrin 17 against ethanol-induced gross and histological damage was studied after capsaicin-induced defunctionalization of afferent neurons, pretreatment with the calcitonin gene-related peptide receptor antagonist human calcitonin gene-related peptide8-37, anti-calcitonin gene-related peptide antibodies, and the NO synthase inhibitor NG-nitro-L-arginine.

RESULTS

Gastrin 17 (1-25 pmol/kg) dose-dependently prevented mucosal damage caused by ethanol. Protection was inhibited by functional ablation of afferent neurons or pretreatment with human calcitonin gene-related peptide8-37 (50% inhibitory dose, 86 pmol.kg-1.min-1), anticalcitonin gene-related peptide antibodies, or NG-nitro-L-arginine (50% inhibitory dose, 1 mg/kg). L-Arginine but not D-arginine reversed the effect of NG-nitro-L-arginine. Effects on gross damage were paralleled by histology. Protective doses of gastrin 17 increased gastric mucosal blood flow and, in addition, elevated plasma gastrin concentrations to the same extent as intragastric peptone perfusion.

CONCLUSIONS

Gastrin 17 has potent gastroprotective activity that involves afferent neurons, calcitonin gene-related peptide, and NO.

Fetal echocardiography during indomethacin treatment

Fetal echocardiograms were evaluated in 315 studies performed in 107 fetuses exposed to indomethacin. In the majority of cases, the results of the fetal echocardiography study were within normal limits (74%). The most common abnormal phenomena were tricuspid valve regurgitation (10%), ductal constriction (6%), tricuspid valve regurgitation and ductal constriction (5%), an increased ductal velocity (2%), and other (3%). The difference between the prevalence of ductal constriction in the whole series of studies (11%) compared to the prevalence of ductal constriction per fetus (25%) (p < 0.001) suggests that this phenomenon was only temporary and disappeared when medication was discontinued. The mean gestational age for detection of tricuspid valve regurgitation was 27.7 +/- 2.8 weeks and for ductal constriction, 30.9 +/- 2.1 weeks (t-test, p < 0.01). Trivial tricuspid valve regurgitation was detected at a mean of 26.7 +/- 2.2 weeks and significant tricuspid valve regurgitation at 29.6 +/- 2.3 weeks (t-test, p < 0.01). We conclude that indomethacin treatment is relatively safe for the fetal heart. The most common side-effects are tricuspid valve regurgitation and ductal constriction. Tricuspid valve regurgitation may be detected before ductal constriction, but by itself it is not a contraindication for the continued use of indomethacin.

[Clinical follow up in a case of fetal arrhythmia--review of the literature]

Fetal heart arrhythmias are divided into 3 categories: 1. extrasystoles 2. tachycardia and 3. bradycardia. In each of these fetal echocardiography follow-up is necessary during the pregnancy. Extrasystoles are usually evaluated every 2 weeks, are mostly benign and no pharmacological treatment is necessary. Vaginal delivery is recommended. Tachycardia should be monitored every week for any evidence of incoming fetal heart failure. In such circumstances pregnant women should be in hospitalized and pharmacological treatment is strongly recommended, usually with digoxin or digoxin and verapamil. Furthermore, other drugs were reported. In a case of bradycardia fetal echocardiography should be performed every week. Fetal heart failure usually leads to cesarean sections, similar like in cases of tachycardia.

[Echocardiography of the fetal heart. Analysis of 350 successive examinations]

From July 1st 1990 do June 30th 1992 517 fetal echocardiography examinations were performed at the Department of Sonography, Polish Mother Memorial Hospital, (Toshiba 270 SA or Acuson 128 XP) between 20th and 41st gestation weeks. The medical indications for fetal heart examinations were presented. On the basis of echo preliminary diagnoses with 350 newborn's clinical assessment, our own results were reviewed. Correct heart anatomy was described in 94%. In conclusions we suggest that fetal heart assessment (anatomy of the 4 chambers) should be included in a routine screening obstetrical scan in the second half of the pregnancy.

Role of calcitonin gene-related peptide and nitric oxide in the gastroprotective effect of capsaicin in the rat

BACKGROUND

Capsaicin-sensitive neurons contain various peptides including calcitonin gene-related peptide. This study examines (1) whether calcitonin gene-related peptide is involved in capsaicin-induced gastroprotection and (2) whether nitric oxide and prostaglandin are required for calcitonin gene-related peptide to prevent mucosal injury.

METHODS

Gastroprotection by capsaicin or calcitonin gene-related peptide against ethanol-induced gross and histological damage was studied after pretreatment with the calcitonin gene-related peptide receptor antagonist, human calcitonin gene-related peptide8-37, anti-calcitonin gene-related peptide antibodies, and NG-nitro-L-arginine.

RESULTS

Protection by capsaicin was dose-dependently (50% inhibitory dose, 305 pmol.kg-1.min-1) antagonized by human calcitonin gene-related peptide8-37 and significantly attenuated by anti-calcitonin gene-related peptide antibodies. NG-nitro-L-arginine dose-dependently inhibited the protective effect of calcitonin gene-related peptide (50% inhibitory dose, 0.9 mg/kg), 3 mg/kg completely blocking protection. L-Arginine reversed the effects of NG-nitro-L-arginine. Protection by calcitonin gene-related peptide was neither associated with increased prostaglandin formation nor inhibited by indomethacin.

CONCLUSIONS

The results suggest that calcitonin gene-related peptide is an essential mediator of the protection elicited by stimulation of capsaicin-sensitive neurons and that the protective effect of calcitonin gene-related peptide is lost after blockade of the nitric oxide system but not the prostaglandin system.

[Doppler flow evaluation of atrio-ventricular valve blood flow in the fetal heart during the second half of normal pregnancy]

39 normal fetal heart examinations were evaluated since 20 week of gestation to term, and Doppler blood flow was analysed for mitral and tricuspid valves. The measurements were done always in good 4 chamber view and qualitative and quantitative analysis were performed, in terms of describing E and A waves and maximal velocity against gestational age. In all of the cases between 20 and 34 weeks of gestation there were type E < A Doppler waveform, and since 35 week of gestation there was also type E = A. There were only 2 cases with type E > A, both near term. This Doppler waveform may depends on maturity of the fetal myocardium. The maximal velocity for the atrio-ventricular valves did not correlated with gestational age. The average max value for mitral valve was 43 +/- 10 cm/s and for tricuspid valve 50 +/- 11 cm/s (p < 0.01).

Fetal endocarditis in left atrial isomerism - a case report

We report a case of fetal endocarditis coexisting with a congenital heart defect: a common atrium (left atrial isomerism) with complete congenital heart block. The case was studied by echocardiography from 32 to 39 weeks of gestation. A postmortem examination was carried out a few hours after Cesarean section. The autopsy, histopathological and immunohistochemical findings revealed endocarditis. We think that abnormal turbulent systolic and diastolic flow of the semilunar valve, seen in fetal Doppler echocardiography, may be a sign of fetal endocarditis even though clear evidence of vegetations were not seen.

2D echocardiographic assessment of the fetal heart size in the 2nd and 3rd trimester of uncomplicated pregnancy

We report simple methods for assessing the fetal heart size by calculating the ratio of the area of the four chambers to the chest area when viewed in the same plane. The average value for this ratio in normal 99 fetal hearts was 0.30 +/- 0.05 and in 16 cases of fetal cardiomegaly it was 0.42 +/- 0.05. The difference was statistically significant (P less than 0.01). A second method is presented which involves measurements of the AP diameter of the heart in the longitudinal plane of the fetal trunk divided by the AP diameter of the chest just above the liver. The average value of this ratio in the normal group was 0.49 +/- 0.06. In a group with cardiomegaly, the average value was 0.62 +/- 0.04 and the difference was statistically significant (P less than 0.01). These methods to calculate heart size use only screen data, and are a simple tool to evaluate fetal heart cardiomegaly.

Pulmonary metastases: pathological anatomy

In most cases, the histopathological examination of pulmonary metastases will lead to vital clues indicating the primary tumor even after years of disease-free intervals. When evaluating 344 metastases of 100 patients, correlation to the known primary tumor was possible in 98% of the cases. Important additional information may be gained by regression grading of metastases, for example after chemotherapy. In 28 metastases of 4 patients suffering from primary tumors of the testicle, no vital tumor tissue could be demonstrated. The age peak of patients with surgically removed pulmonary metastases was between 40 and 50 years, varying widely, however, depending on the primary lesion. The size of the resected metastases was between 1 and 100 mm, with a peak of 6-10 mm. The examination of early metastases enhanced our knowledge concerning the different phases of metastatic spread such as embolization, implantation, metastatic growth with neoangiogenesis, spontaneous or therapeutically induced tumor regression and local reactions of the pulmonary tissue. The characterization of tumor tissue using, among others, immunohistochemical techniques will lead to clinical and therapeutic consequences.

[Crohn disease-associated pancreatitis: is there a new extra-intestinal manifestation of the disease?]

We report the case of a 23-year old woman suffering from Crohn's ileocolitis for 14 years who died of a prolonged shock followed by hyperglycaemia. The post-mortem examination showed an acute pancreatitis. There was no hint for Crohn's disease of the duodenum or primary sclerosing cholangitis (PSC). Unexplained Pancreatitis coincident with Crohn's disease might be a possible extraintestinal manifestation of the disease. However such association remains speculative at the moment. Further studies based on morphological, functional, immunological and epidemiological data are required. Review of the literature and our own data show the necessity to look attentive for other causes of acute pancreatitis associated with Crohn's disease (PSC, pancreas divisum, drug induced-pancreatitis).

Echocardiographic evaluation of fetal arrhythmias

When during routine prenatal care, the auscultation++ of the fetal heart beat reveals an abnormal rate or rhythm, two things are needed: 1) the accurate diagnosis of the arrhythmia, and 2) the hemodynamic impact of the rhythm disturbance on the fetus. In Poland, external cardiotocography is the most widely Supported in part by the American Heart Association, Delaware Affiliate, Grant = 41161 available diagnostic system used by obstetricians, but it records only the mean heart rate or the instantaneous heart rate. Cardiotocography is therefore useful only in identifying tachycardia or bradycardia. The most frequent tape of fetal arrhythmia is an irregular rhythm, especially premature contractions (1, 15, 18). We believe that any disturbance in fetal cardiac condition should be evaluated more fully by fetal echocardiography.

[Hyaluronic acid and N-terminal procollagen-III-peptide in the urine in inflammatory and degenerative joint diseases]

In a cross-sectional study of 130 patients (main diagnosis: rheumatoid arthritis, n = 41, osteoarthritis, n = 39; ankylosing spondylitis, n = 28) we measured the concentrations of hyaluronan (HA) and the N-terminal propeptide of type-III collagen (NP III P) in urine and evaluated the relationship with their serum levels. Increased HA levels in serum correlated with increased urinary excretion (r = 0.69 for patients with active rheumatoid arthritis). Only patients with rheumatoid arthritis showed significantly elevated HA concentrations in urine (mean = 1,493 micrograms/mmol creatinine). Because of relatively wide fluctuations in urinary HA in normals (mean = 944, standard deviation 818 micrograms/mmol creatinine) and only modest differences between groups, the diagnostic accuracy of urinary HA measurements is inferior to serum determinations. NP III P showed no significant differences between patients and controls (means 10.5 to 15 micrograms/mmol creatinine). Obviously, renal excretion is of minor importance in the metabolism of HA and NP III P. The possible diagnostic usefulness of determinations of these parameters in serum is not enhanced by measurements in urine.

Detection of pulmonary aspiration in children by radionuclide "salivagram"

The radionuclide "salivagram" was introduced to document the aspiration of oral secretions in patients who are at risk. Approximately one-third of patients studied had positive tests. A positive study does not necessarily imply that patients are at risk for aspiration after gastroesophageal reflux. However, sequential images of the lung fields after the oral radioactivity has cleared may be a sensitive technique for detecting aspiration in infants and children following reflux.

[Initial clinical experiences in the treatment of chronic polyarthritis with a new monokine release inhibitor]

Cytokines such as Interleukin-1 (IL-1) are important modulators of the cell-mediated immune response and play a paramount role in inflammatory autoimmune disease. We report on preliminary clinical experiences with a new, tricyclic substance [( 10-Methoxy-4H-benzo[4,5]cyclo-hepta-[1,2-b]thiophene-4- ylidene]acetic acid, MW 284), which inhibits the release of interleukin-1 alpha and -beta from cultured murine macrophages or human mononuclear cells. The study included 12 patients (rheumatoid arthritis, n = 9; hemochromatotic arthropathy, n = 1; psoriatic arthropathy, n = 1; seronegative spondylarthropathy, n = 1). Eight patients were treated for a total of 8 weeks, receiving a median dose of 800 mg/d of the substance. Due to significant clinical benefits, two patients continued for a total of six months. Administration of the drug was discontinued in two patients because of severe urticaria and lack of compliance, respectively. Four out of 10 patients showed clinical improvement according to Ritchie-Index, pain score, ESR and CRP. Side effects were diffuse gastrointestinal symptoms (4/12), temporary impairment of liver function (4/12) and allergic skin reactions (3/12).

Reversibility of long-term effects of GnRH agonist administration on testicular histology and sperm production in the nonhuman primate

The present investigation evaluates the long-term effects of GnRH agonist treatment on testicular histology, sperm production and the subsequent recovery of these parameters. Four adult rhesus monkeys (M. mulatta) were treated with the GnRH agonist nafarelin (D-Nal(2)6-GnRH), released from i.m.--injected poly-D,L-lactic-co-glycolide microspheres for 20 months. Monthly injection of the GnRH agonist preparation uniformly suppressed serum levels of bioactive LH and testosterone. The size of the testis was reduced to about 30% of pretreatment. Sperm counts were suppressed to azoospermia for a total period of 53 and 77 weeks, respectively, in two monkeys and the other two animals were extremely oligozoospermic. Evaluation of testicular biopsy material after 6, 12 and 20 months of treatment revealed decreased seminiferous tubule diameter, spermatogenic disruption at the level of spermatogonia or spermatocytes, accumulation of lipid droplets and secondary lysosomes in the Sertoli cell cytoplasm, and increased thickness of the tubular wall compared with pretreatment histology. Electron microscopic examination revealed that the increased wall thickness was due to an enlargement of the inner collagen layer. No evidence of fibrosis or calcification could be obtained. Leydig cells were atrophic. Serum hormones, testis size and sperm counts returned to pretreatment values within 5 to 8, 13 to 16, and 18 weeks, respectively, after termination of treatment. Testicular histology, assessed 8 months after cessation of treatment, was indistinguishable from pretreatment. It is concluded that GnRH agonist-containing microspheres are a feasible modality for sustained administration of GnRH agonists and GnRH agonist-induced suppression of pituitary and testicular function is reversible following withdrawal of treatment. Thus, GnRH agonists may have a potential for regulation of male fertility and, presumably, also for treatment of precocious puberty.