Disturbance of Growth in Pediatric Patients Due to Osteomyelitis Caused by Growth Plate Infection

Osteomyelitis, a severe bone infection, poses a multifaceted challenge to healthcare professionals. While its pathophysiology and treatment have been extensively studied, the impact of osteomyelitis on skeletal growth, particularly in pediatric patients, is an area that warrants attention. This abstract highlights the significance of understanding and managing growth disturbances in osteomyelitis, providing key findings and recommendations for clinicians. Understanding growth disturbance in osteomyelitis is essential because it can lead to lifelong consequences for pediatric patients. The infection may affect the growth plate, leading to limb length discrepancies, angular deformities, and functional impairments. These complications not only diminish the quality of life but also pose a substantial economic burden on the healthcare system. Therefore, early recognition and intervention are crucial. Key findings indicate that the risk of growth disturbances in osteomyelitis is particularly high in pediatric patients due to the vulnerability of the growth plate. Timely diagnosis, appropriate management, and targeted interventions can mitigate the long-term sequelae of growth disturbances. These include utilizing advanced imaging techniques to assess the extent of growth plate involvement, optimizing antibiotic therapy, and employing surgical techniques like epiphysiodesis, guided growth, or corrective osteotomies. Additionally, fostering a multidisciplinary approach that involves orthopedic surgeons, infectious disease specialists, and pediatric endocrinologists is vital to achieving successful outcomes. Recommendations for managing growth disturbance in osteomyelitis encompass early detection, meticulous monitoring, and a tailored treatment plan. Healthcare providers should remain vigilant for signs of growth plate involvement in osteomyelitis patients, especially in the pediatric population. A thorough evaluation, including advanced imaging and clinical assessment, is essential for accurate diagnosis. Close collaboration between specialists to address the infection and its skeletal consequences is crucial. Furthermore, patient and family education plays a pivotal role in fostering compliance with the treatment regimen. In conclusion, understanding and managing growth disturbances in osteomyelitis is paramount, particularly in pediatric patients. The implications of growth plate involvement are significant, and timely intervention is essential to prevent lifelong consequences. By implementing a comprehensive approach that combines accurate diagnosis, multidisciplinary collaboration, and patient education, healthcare professionals can enhance the quality of life and well-being of those affected by this challenging condition.

Cholesterol enriched diet suppresses ATF6 and PERK and upregulates the IRE1 pathways of the unfolded protein response in spontaneously hypertensive rats: Relevance to pathophysiology of atherosclerosis in the setting of hypertension

Many studies have been dedicated to hypertension and hypercholesterolemia, as they are the primary conditions that influence the unfolded protein response (UPR). However, the concurrent effects of these two factors are unknown. Our research used spontaneously hypertensive rats (SHR) fed a cholesterol enriched diet (CED) as model of atherosclerosis formation to discover what effect the simultaneous actions of hypertension and hypercholesterolemia have on the UPR. The combination of hypertension and consumption of a CED (not the CED alone) caused the formation of early atherosclerotic features. Both increased expression of the CCAAT-enhancer-binding protein (CHOP) and the insulin induced gene 1 (INSIG1), which is the target gene of the sterol regulatory element-binding protein 1-c (SREBP1-c), and decreased expression of the spliced x-box binding protein1 (sXBP1) mRNA were observed in the SHR fed a CED. Cholesterol overload strongly suppressed glucose regulated protein 78 (GRP78), glucose regulated protein 94 (GRP 94), and the expression of CHOP and INSIG1 mRNA in both normotensive and hypertensive rats. Unlike other UPR factors, the sXBP1 mRNA expression was strongly downregulated in SHR fed a normal diet but upregulated in those fed a CED. The changes to UPR in the SHR fed a CED were associated with improvement of the initially impaired heart function of the rats.

Reproductive competency and mitochondrial variation in aged Syrian hamster oocytes

The hamster is a useful model of human reproductive biology because its oocytes are similar to those in humans in terms of size and structural stability. In the present study we evaluated fecundity rate, ovarian follicular numbers, ova production, mitochondrial number, structure and function, and cytoplasmic lamellae (CL) in young (2-4 months) and old (12-18 months) Syrian hamsters (Mesocricetus auratus). Young hamsters had higher fertilisation rates and larger litters than old hamsters (100 vs 50% and 9.3±0.6 vs 5.5±0.6, respectively). Ovarian tissue from superovulated animals showed a 46% decrease in preantral follicles in old versus young hamsters. There was a 39% reduction in MII oocyte number in old versus young hamsters. Young ova had no collapsed CL, whereas old ova were replete with areas of collapsed, non-luminal CL. Eighty-nine per cent of young ova were expanded against the zona pellucida with a clear indentation at the polar body, compared with 58.64% for old ova; the remaining old ova had increased perivitelline space with no polar body indentation. Higher reactive oxygen species levels and lower mitochondrial membrane potentials were seen in ova from old versus young hamsters. A significant decrease in mitochondrial number (36%) and lower frequency of clear mitochondria (31%) were observed in MII oocytes from old versus young hamster. In conclusion, the results of the present study support the theory of oocyte depletion during mammalian aging, and suggest that morphological changes of mitochondria and CL in oocytes may be contributing factors in the age-related decline in fertility rates.

Anti-inflammatory and antioxidant effect of cerium dioxide nanoparticles immobilized on the surface of silica nanoparticles in rat experimental pneumonia

A massage with the potent counter-inflammatory material, cerium dioxide nanoparticles, is promising and the antioxidant properties of CeO₂ are considered the main, if not the only, mechanism of this action. Nevertheless, the elimination of ceria nano-particles from the organism is very slow and there is a strong concern for toxic effect of ceria due to its accumulation. To overcome this problem, we engineered a combined material in which cerium nanoparticles were immobilized on the surface of silica nanoparticles (CeO₂ NP), which is shown to be easily removed from an organism and could be used as carriers for nano-ceria. In our study particle size was 220±5nm, Zeta-potential -4.5mV (in water), surface charge density -17.22μC/cm² (at pH 7). Thirty-six male Wistar rats, 5 months old and 250-290g were divided into four groups: 1) control; 2) CeO₂ NP treatment; 3) experimental pneumonia (i/p LPS injection, 1mg/kg); and 4) experimental pneumonia treated with CeO₂ NP (4 times during the study in dosage of 0.6mg/kg with an orogastric catheter). Gas exchange and pulmonary ventilation were measured four times: 0, 1, 3 and 24h after LPS injection in both untreated and CeO₂ NP-treated animals. The mRNA of TNF-α, Il-6, and CxCL2 were determined by RT-PCR. ROS-generation in blood plasma and lung tissue homogenates were measured by means of lucigenin- and luminol-enhanced chemiluminescence. Endotoxemia in the acute phase was associated with: (1) pathological changes in lung morphology; (2) increase of ROS generation; (3) enhanced expression of CxCL2; and (4) a gradual decrease of VO₂ and V_E. CeO2 NP treatment of intact animals did not make any changes in all studied parameters except for a significant augmentation of VO₂ and V_E. CeO₂ NP treatment of rats with pneumonia created positive changes in diminishing lung tissue injury, decreasing ROS generation in blood and lung tissue and decreasing pro-inflammatory cytokine expression (TNF-α, Il-6 and CxCL2). Oxygen consumption in this group was increased compared to the LPS pneumonia group. In our study we have shown anti-inflammatory and antioxidant effects of CeO₂ NP. In addition, this paper is the first to report that CeO₂ NP stimulates oxygen consumption in both healthy rats, and rats with pneumonia. We propose the key in understanding the mechanisms behind the phenomena lies in the property of CeO₂ NP to scavenge ROS and the influence of this potent antioxidant on mitochondrial function. The study of biodistribution and elimination of СеО₂NP is the purpose of our ongoing study.

Highly fluorescent resorcinarene cavitand nanocapsules with efficient renal clearance

Nanomaterial based imaging approaches hold substantial promise in addressing current diagnostic and therapeutic challenges. One of the key requirements for the successful clinical translation of nanomaterials is their complete clearance from the body within a reasonable time period preferably via the renal filtration route. This article describes the synthesis of highly fluorescent, water soluble, resorcinarene cavitand nanocapsules and demonstrates their effective renal clearance in mice. The synthesis and functionalization of nanocapsules was accomplished in a one-pot operation via thiol-ene reactions without involving self-assembly, sacrificial templates or emulsions. Water soluble resorcinarene cavitand nanocapsules obtained by this approach were covalently functionalized with Alexa Fluor 750. Highly fluorescent nanocapsules with hydrodynamic diameters of 122 nm and 68 nm and extinction coefficients of 1.3 × 10(9) M(-1) cm(-1) and 1.5 × 10(8) M(-1) cm(-1) respectively were prepared by varying the reaction conditions. The in vivo biodistribution and clearance of these nanocapsules in mice followed by whole-body fluorescence imaging showed that they were both cleared renally within a few hours. Given the inherent encapsulation capabilities of nanocapsules, the renal clearance demonstrated in this work opens up new opportunities for their theranostic applications especially for targeting and treating the urinary tract.

MFGE8 regulates TGF-β-induced epithelial mesenchymal transition in endometrial epithelial cells in vitro

This study investigated the role of milk fat globule-epidermal growth factor-factor 8 (MFGE8) in TGF-β-induced epithelial-mesenchymal transition (EMT) of endometrial epithelial cells. These were in vitro studies using human endometrial epithelial cells and mouse blastocysts. We investigated the ability of TGF-β to induce EMT in endometrial epithelial cells (HEC-1A) by assessment of cytological phenotype (by light and atomic force microscopy), changes in expression of the markers of cell adhesion/differentiation E- and N-cadherin, and of the transcription factor Snail (by immunofluorescence and immunoblotting), and competence to support embryo attachment in a mouse blastocyst outgrowth assay. We also studied the effects of E-cadherin expression in cells transfected by retroviral shRNA vectors specifically silencing MFGE8. Results demonstrated that TGF-β induced EMT as demonstrated by phenotypic cell changes, by a switch of cadherin expression as well as by upregulation of the expression of the mesenchymal markers Snail and Vimentin. Upon MFGE8 knockdown, these processes were interfered with, suggesting that MFGE8 and TGF-β together may participate in regulation of EMT. This study demonstrated for the first time that endometrial MFGE8 modulates TGF-β-induced EMT in human endometrium cells.

Characterization of secreted proteins of 2-cell mouse embryos cultured in vitro to the blastocyst stage with and without protein supplementation

PURPOSE

To identify the secreted proteins of murine embryos grown in vitro.

METHODS

Two-cell mouse embryos (n=432) were randomly allocated to culture to the blastocyst stage in protein-free and in protein-supplemented (3 % BSA) media. Proteins were separated by SDS-PAGE; bands were visualized by coomassie staining, followed by in-gel trypsin digestion and liquid chromatography-tandem mass spectrometry. RT-PCR and confocal microscopy were used to confirm gene/protein expression in blastocysts.

RESULTS

Of all individually identified proteins, 34 and 23 were found in embryos cultured without and with BSA, respectively, and 20 were common. Identified proteins having an N-terminal secretory sequence or transmembrane domains located on the extracellular backbone were postulated as secreted proteins. Gene and protein expression for two selected molecules were confirmed. Functional analysis revealed over-represented processes related to lipid metabolism, cyclase activity, and cell adhesion/membrane functions.

CONCLUSIONS

This study provided evidence to further characterize secreted proteins by mouse embryos grown from the 2-cell to the blastocyst stage in vitro. Because of homology between murine and human, these results may provide information to be translated to the clinical setting.

Age-associated metabolic and morphologic changes in mitochondria of individual mouse and hamster oocytes

Background

In human oocytes, as in other mammalian ova, there is a significant variation in the pregnancy potential, with approximately 20% of oocyte-sperm meetings resulting in pregnancies. This frequency of successful fertilization decreases as the oocytes age. This low proportion of fruitful couplings appears to be influenced by changes in mitochondrial structure and function. In this study, we have examined mitochondrial biogenesis in both hamster (Mesocricetus auratus) and mouse (Mus musculus) ova as models for understanding the effects of aging on mitochondrial structure and energy production within the mammalian oocyte.

Methodology/Principal Findings

Individual metaphase II oocytes from a total of 25 young and old mice and hamsters were collected from ovarian follicles after hormone stimulation and prepared for biochemical or structural analysis. Adenosine triphosphate levels and mitochondrial DNA number were determined within individual oocytes from young and old animals. In aged hamsters, oocyte adenosine triphosphate levels and mitochondrial DNA molecules were reduced 35.4% and 51.8%, respectively. Reductions of 38.4% and 44% in adenosine triphosphate and mitochondrial genomes, respectively, were also seen in aged mouse oocytes. Transmission electron microscopic (TEM) analysis showed that aged rodent oocytes had significant alterations in mitochondrial and cytoplasmic lamellae structure.

Conclusions/Significance

In both mice and hamsters, decreased adenosine triphosphate in aged oocytes is correlated with a similar decrease in mtDNA molecules and number of mitochondria. Mitochondria in mice and hamsters undergo significant morphological change with aging including mitochondrial vacuolization, cristae alterations, and changes in cytoplasmic lamellae.

Comparative study of long- and short-pulsed electric fields for treating melanoma in an in vivo mouse model

A mouse melanoma model was set up with green fluorescent protein (GFP) expression in vivo. With the same energy, long- (1 ms) and short- (300 ns) pulsed electric fields were delivered to two melanomas injected into the same mouse. The tumor growth and green fluorescence were followed up to compare the different treatment efficacy of long and short pulses. After two days post treatment, short pulse-treated tumors showed a significantly lower tumor volume compared with long pulse-treated tumors (n=8, p<0.05). On 8 experimental animals, a short nanosecond pulsed electric field (nsPEF) had lesser or delayed effects on GFP quenching and greater effects in reducing tumor size. Short pulses produced by nsPEFs can cause melanoma regression with less effect on the plasma membrane.

Histopathological follow-up by tissue micro-array in a survival study after melanoma treated by nanosecond pulsed electric fields (nsPEF)

A recent study has shown that nanosecond pulsed electric fields (nsPEF) can affect the intracellular structures of melanoma within weeks. nsPEF is a non-drug, non-thermal treatment using ultrashort, intense pulsed electric fields with nanosecond durations. In the current study we followed up melanoma histopathology and metastasis with tissue micro-array 5 months post-nsPEF. After nsPEF treatment, tumor growth, tumor histology, metastasis, peri-tumor vessel and micro-vessel density were examined for the effect of nsPEF treatment on melanoma in vivo. The 17 nsPEF-treated mice were tumor-free for 169 days, significantly longer than those 19 control mice bearing melanoma without nsPEF. Histopathology follow-up showed that melanoma did not recur to the primary injection place after complete elimination. Compared with the control tumor, nsPEF-treated tumors present decreased micro-vessel density in a time-course manner in this survival study. Treatment with nsPEF caused continuous histopathological changes in melanomas, eliminated melanoma without recurrence at the primary site and prolonged animal survival time by inhibiting tumor blood supply and leading to tumor infarction. Thus, nsPEF could be applied in a non-ionizing therapeutic approach, without other agents, to locally treat tumors within a defined boundary.

Apoptosis initiation and angiogenesis inhibition: melanoma targets for nanosecond pulsed electric fields

Many effective anti-cancer strategies target apoptosis and angiogenesis mechanisms. Applications of non-ionizing, nanosecond pulsed electric fields (nsPEFs) induce apoptosis in vitro and eliminate cancer in vivo; however in vivo mechanisms require closer analysis. These studies investigate nsPEF-induced apoptosis and anti-angiogenesis examined by fluorescent microscopy, immunoblots, and morphology. Six hours after treatment with one hundred 300 ns pulses at 40 kV/cm, cells transiently expressed active caspases indicating that caspase-mediated mechanisms. Three hours after treatment transient peaks in Histone 2AX phosphorylation coincided with terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells and pyknotic nuclei, suggesting caspase-independent mechanisms on nuclei/DNA. Large DNA fragments, but not 180 bp fragmentation ladders, were observed, suggesting incomplete apoptosis. Nevertheless, tumor weight and volume decreased and tumors disappeared. One week after treatment, vessel numbers, vascular endothelial growth factor (VEGF), platelet derived endothelial cell growth factor (PD-ECGF), CD31, CD35 and CD105 were decreased, indicating anti-angiogenesis. The nsPEFs activate multiple melanoma therapeutic targets, which is consistent with successes of nsPEF applications for tumor treatment in vivo as a new cancer therapeutic modality.

A new pulsed electric field therapy for melanoma disrupts the tumor's blood supply and causes complete remission without recurrence

We have discovered a new, ultrafast therapy for treating skin cancer that is extremely effective with a total electric field exposure time of only 180 microsec. The application of 300 high-voltage (40 kV/cm), ultrashort (300 nsec) electrical pulses to murine melanomas in vivo triggers both necrosis and apoptosis, resulting in complete tumor remission within an average of 47 days in the 17 animals treated. None of these melanomas recurred during a 4-month period after the initial melanoma had disappeared. These pulses generate small, long-lasting, rectifying nanopores in the plasma membrane of exposed cells, resulting in increased membrane permeability to small molecules and ions, as well as an increase in intracellular Ca(2+), DNA fragmentation, disruption of the tumor's blood supply and the initiation of apoptosis. Apoptosis was indicated by a 3-fold increase in Bad labeling and a 72% decrease in Bcl-2 labeling. In addition, microvessel density within the treated tumors fell by 93%. This new therapy utilizing nanosecond pulsed electric fields has the advantages of highly localized targeting of tumor cells and a total exposure time of only 180 microsec. These pulses penetrate into the interior of every tumor cell and initiate DNA fragmentation and apoptosis while at the same time reducing blood flow to the tumor. This new physical tumor therapy is drug free, highly localized, uses low energy, has no significant side effects and results in very little scarring.

Ultrashort electric pulse induced changes in cellular dielectric properties

The interaction of nanosecond duration pulsed electric fields (nsPEFs) with biological cells, and the models describing this behavior, depend critically on the electrical properties of the cells being pulsed. Here, we used time domain dielectric spectroscopy to measure the dielectric properties of Jurkat cells, a malignant human T-cell line, before and after exposure to five 10ns, 150kV/cm electrical pulses. The cytoplasm and nucleoplasm conductivities decreased dramatically following pulsing, corresponding to previously observed rises in cell suspension conductivity. This suggests that electropermeabilization occurred, resulting in ion transport from the cell's interior to the exterior. A delayed decrease in cell membrane conductivity after the nsPEFs possibly suggests long-term ion channel damage or use dependence due to repeated membrane charging and discharging. This data could be used in models describing the phenomena at work.

Nanosecond electric pulses penetrate the nucleus and enhance speckle formation

Nanosecond electric pulses generate nanopores in the interior membranes of cells and modulate cellular functions. Here, we used confocal microscopy and flow cytometry to observe Smith antigen antibody (Y12) binding to nuclear speckles, known as small nuclear ribonucleoprotein particles (snRNPs) or intrachromatin granule clusters (IGCs), in Jurkat cells following one or five 10ns, 150kV/cm pulses. Using confocal microscopy and flow cytometry, we observed changes in nuclear speckle labeling that suggested a disruption of pre-messenger RNA splicing mechanisms. Pulse exposure increased the nuclear speckled substructures by approximately 2.5-fold above basal levels while the propidium iodide (PI) uptake in pulsed cells was unchanged. The resulting nuclear speckle changes were also cell cycle dependent. These findings suggest that 10ns pulses directly influenced nuclear processes, such as the changes in the nuclear RNA-protein complexes.

Nanosecond pulsed electric fields cause melanomas to self-destruct

We have discovered a new, drug-free therapy for treating solid skin tumors. Pulsed electric fields greater than 20 kV/cm with rise times of 30 ns and durations of 300 ns penetrate into the interior of tumor cells and cause tumor cell nuclei to rapidly shrink and tumor blood flow to stop. Melanomas shrink by 90% within two weeks following a cumulative field exposure time of 120 micros. A second treatment at this time can result in complete remission. This new technique provides a highly localized targeting of tumor cells with only minor effects on overlying skin. Each pulse deposits 0.2 J and 100 pulses increase the temperature of the treated region by only 3 degrees C, ten degrees lower than the minimum temperature for hyperthermia effects.

Leukemic cell intracellular responses to nanosecond electric fields

Intense, nanosecond (ns) pulsed electric fields (PEFs) are known to affect the intracellular structures of cells. The probability of preferentially inducing subcellular effects increases with decreasing pulse length while effects on the plasma membrane are diminished. This has been demonstrated by applying electrical pulses of 60 and 10 ns duration with electric field intensities of up to 6.5 MV/m to HL-60 cells. Using confocal microscopy, PEF-induced changes in the integrity of the plasma membrane and nucleus were measured by recording fluorescence changes with propidium iodide (PI) and acridine orange (AO), respectively. Results suggest that high voltage, nsPEFs target the nucleus and modify cellular functions while plasma membrane effects are delayed and become smaller as pulse duration is shortened. Cell viability was not affected by these pulses. In spite of the high pulsed electric fields, thermal effects can be neglected because of the ultrashort pulse duration. The results suggest application of this ultrashort pulse technology to modulate nuclear structure and function for potential therapeutic benefit.

Intermittent hypoxia: mechanisms of action and some applications to bronchial asthma treatment

Being essentially cut off from the global scientific community, Ukrainian and Russian scientists have developed a new concept for the beneficial use of adaptation to artificial intermittent hypoxia in treating of many diseases. The basic mechanisms underlying intermittent hypoxic training were elaborated mainly in three areas: regulation of respiration, free radical production and mitochondrial respiration. Twenty-year experience of the application of intermittent hypoxic therapy for the treatment of chronic obstructive bronchitis and bronchial asthma allows affirming that the adaptation to this kind of hypoxia causes a significant improvement of the clinical picture or even a complete recovery. The absence of negative side effects, typically observed during drug therapy, and the stimulation of organism's general, nonspecific resistance, makes the hypoxic therapy a treatment with a future. A special note is devoted to the use of intermittent hypoxic training in industrial health care for the purpose of prophylaxis and treatment of professional diseases.

In vivo effect of leukemia inhibitory factor (LIF) and an anti-LIF polyclonal antibody on murine embryo and fetal development following exposure at the time of transcervical blastocyst transfer

Leukemia inhibitory factor (LIF) enhances in vitro murine preimplantation development in a time- and dose-dependent fashion. Knockout experiments have demonstrated that endometrial LIF is essential for in vivo murine implantation. We assessed the impact of LIF and an anti-LIF polyclonal antibody (pab) on in vivo development and developed a novel and successful nonsurgical method of embryo transfer for this species, a transcervical blastocyst transfer technique. The objectives of this study were to evaluate the effects of LIF and the anti-LIF pab on 1) implantation, resorption, pregnancy, and viability rates and 2) the overall structural and skeletal development. Two-cell embryos were recovered from superovulated mated donors, cultured to the expanded blastocyst stage, and transferred transcervically into pseudopregnant recipients. Exposure to 5000 U/ml LIF resulted in significant increases in implantation, pregnancy, and viability rates compared with controls. A similar dose of pab produced overall inhibitory effects with a significant decrease in implantation rate. Paradoxically, lower pab doses resulted in significantly increased viability rates. Exposure to LIF had no effect on fetoplacental development. However, pab treatments had variable but significant negative effects on placental length, ossification of the exoccipital bone, and vertebral space width compared with controls. Exposure of murine blastocysts to LIF at the time of transcervical transfer resulted in pronounced positive effects on implantation and pregnancy rates without affecting fetal development. A similar pab dose dramatically reduced implantation and pregnancy rates; at high and low doses, pab produced deleterious effects on placental and skeletal development.

Mechanisms of taurine antihypoxic and antioxidant action

The study was undertaken to elucidate the effects of taurine on lipid peroxidation (LP) intensity and membrane Na+, K+-ATPase activity in a hypoxic rat model. It was shown that 3 intraperitoneal (i.p.) injections of 200 mg/kg of taurine prevented hypoxia-induced lactate accumulation and LP in brain, liver, and heart tissues and prevented the decrease of Na+, K+-ATPase activity in the liver. It is suggested that the effect of taurine on LP could be due to the taurine antiacidotic action as well as to its membrane stabilizing activity.

Geriatric men at altitude: hypoxic ventilatory sensitivity and blood dopamine changes

BACKGROUND

Short-term exposure to high-altitude hypoxia increases hypoxic ventilatory sensitivity (HVS) in healthy humans. Dopamine (DA) is the implicated neurotransmitter in carotid body (CB) chemoreceptor response, and the microenvironmental conditions in CB tissue are comparable to blood. Continuous DA infusion affected ventilation in animals and humans. Age-related oscillations in blood DA levels may influence peripheral chemoreflexes.

OBJECTIVE

Hypoxic ventilatory responses (HVR) relative to blood DA concentration and its precursor, dihydroxyphenylalanine (DOPA) was measured in young and elderly men during short-term altitude adaptation.

METHODS

Nine elderly climbers (group 1:61+/-1.4 years) and 7 young healthy subjects (group 2: 23+/-2 years) were tested at sea level on day 0, on day 3 after passive transport to 2,200 m, and on day 14 after climbing to 4,200 and 5,642 m.

RESULTS

Sea level HVR in group 1 was 47% lower than in group 2, accompanied by higher blood DOPA (300%) and DA (37%) content. Initial DA and DOPA concentrations showed a negative correlation with initial HVR but a positive correlation with age. Passive transport to middle altitude (2,200 m) increased HVS, doubling HVR slopes in groups 1 and 2 and producing increased maximum expired minute ventilation during isocapnic rebreathing (29 and 28%, respectively). Day 3 2,200-meter blood DOPA content decreased by 22% in group 1 and increased by 300% in group 2. DA increased in both groups.

CONCLUSION

The relationship between HVR and the reciprocal DA and DOPA values seen in both groups is associated with age, producing decreased DA receptor sensitivity and enhanced DA reuptake during adaptation to high altitude.

Intermittent hypoxia alters hypoxic ventilatory responses

Intermittent hypoxic training (IHT) shows promise for prevention and treatment of some diseases and efficiently produces great advancement in athletic training. We studied (1) hypoxic ventilatory responses (HVR) in supine and sitting positions during normobaric, isocapnic, progressive hypoxia (rebreathing technique) and (2) lung ventilation and gas exchange while breathing ambient air at rest and during 5 min of breathing 11% O2. Duel measurements were made pre- and post-15-day IHT regimen on 12 (experimental) healthy males (24.6 y.o. +/- 1.9 y.o.) and on 6 (control) healthy males (24.2 y.o. +/- 2.3 y.o.) given pseudo-IHT (p-IHT) without decreasing PiO2. IHT involved rebreathing eucapnic (chemically absorbed) air as P(ET)O2 decreased to 35 mmHg, three 6-7 min sessions, three times a day, with 10 min breaks between each session over a 15 day training period. Without IHT, HVRs were the same in sitting and supine positions at low levels of hypoxic challenge (slope one--S1: P(ET)O2 from 110-60 mm Hg) and significantly higher (by 45%) during severe hypoxia (slope two--S2: P(ET)O2 from 60-35 mm Hg). IHT caused an increase in HVR in both sitting and supine positions: S1 by 70 and 100%, S2 by 158 and 200%, maximal lung ventilation by 35 and 78%, respectively. There were no significant changes in the p-IHT group. IHT also caused enhanced respiratory reactions during sustained hypoxia (lung and alveolar ventilation increased by 36 and 22%, respectively). A striking hypoxic ventilatory sensitivity was noted in subjects with hyper-reactive breathing patterns.

Human hypoxic ventilatory response with blood dopamine content under intermittent hypoxic training

Adaptation to intermittent hypoxia can enhance a hypoxic ventilatory response (HVR) in healthy humans. Naturally occurring oscillations in blood dopamine (DA) level may modulate these responses. We have measured ventilatory response to hypoxia relative to blood DA concentration and its precursor DOPA before and after a 2-week course of intermittent hypoxic training (IHT). Eighteen healthy male subjects (mean 22.8+/-2.1 years old) participated in the study. HVRs to isocapnic, progressive, hypoxic rebreathing were recorded and analyzed using piecewise linear approximation. Rebreathing lasted for 5-6 min until inspired O2 reached 8 to 7%. IHT consisted of three identical daily rebreathing sessions separated by 5-min breaks for 14 consecutive days. Before and after the 2-week course of IHT, blood was sampled from the antecubital vein to measure DA and DOPA content. The investigation associated pretraining high blood DA and DOPA values with low HVR (r = -0.66 and -0.75, respectively), elevated tidal volume (r = 0.58 and 0.37) and vital capacity (r = 0.69 and 0.58), and reduced respiratory frequency (r = -0.89 and -0.82). IHT produced no significant change in ventilatory responses to mild hypoxic challenge (Peto2 from 110 to 70-80 mm Hg; 1 mm Hg = 133.3 Pa) but elicited a 96% increase in ventilatory response to severe hypoxia (from 70-80 to 45 mm Hg). Changes in HVRs were not accompanied by statistically significant shifts in blood DA content (24% change), although a twofold increase in DOPA concentration was observed. Individual subject's changes in DA and DOPA content were not correlated with HVR changes when these two parameters were evaluated in relation to the IHT. We hypothesize that DA flowing to the carotid body through the blood may provoke DA autoreceptor-mediated inhibition of endogenous DA synthesis-release, as shown in our baseline data.

Human hypoxic ventilatory response with blood dopamine content under intermittent hypoxic training

Adaptation to intermittent hypoxia can enhance a hypoxic ventilatory response (HVR) in healthy humans. Naturally occurring oscillations in blood dopamine (DA) level may modulate these responses. We have measured ventilatory response to hypoxia relative to blood DA concentration and its precursor DOPA before and after a 2-week course of intermittent hypoxic training (IHT). Eighteen healthy male subjects (mean 22.8 ± 2.1 years old) participated in the study. HVRs to isocapnic, progressive, hypoxic rebreathing were recorded and analyzed using piecewise linear approximation. Rebreathing lasted for 5-6 min until inspired O2 reached 8 to 7%. IHT consisted of three identical daily rebreathing sessions separated by 5-min breaks for 14 consecutive days. Before and after the 2-week course of IHT, blood was sampled from the antecubital vein to measure DA and DOPA content. The investigation associated pretraining high blood DA and DOPA values with low HVR (r = -0.66 and -0.75, respectively), elevated tidal volume (r = 0.58 and 0.37) and vital capacity (r = 0.69 and 0.58), and reduced respiratory frequency (r = -0.89 and -0.82). IHT produced no significant change in ventilatory responses to mild hypoxic challenge (PetO2 from 110 to 70-80 mmHg; 1 mmHg = 133.3 Pa) but elicited a 96% increase in ventilatory response to severe hypoxia (from 70-80 to 45 mmHg). Changes in HVRs were not accompanied by statistically significant shifts in blood DA content (24% change), although a twofold increase in DOPA concentration was observed. Individual subject's changes in DA and DOPA content were not correlated with HVR changes when these two parameters were evaluated in relation to the IHT. We hypothesize that DA flowing to the carotid body through the blood may provoke DA autoreceptor-mediated inhibition of endogenous DA synthesis-release, as shown in our baseline data.Key words: hypoxic ventilatory response, dopamine, intermittent hypoxia.

Value of sperm morphology assessed by strict criteria for prediction of the outcome of artificial (intrauterine) insemination

The purpose of this study was to investigate the relationship between sperm parameters and the outcome of artificial (intrauterine) insemination (IUI). One hundred and twenty-six patients undergoing 395 consecutive IUI cycles in a 1-year period in our institution were studied. In all cases, controlled ovarian stimulation and hCG-timed IUI were performed, followed by progesterone supplementation of the luteal phase. In 86 patients, (243 cycles) the husband's sperm was utilized, whereas in 40 couples (152 cycles), donor sperm was used due to severe male factor infertility. Among the sperm parameters of the original ejaculate, % normal morphology (assessed by strict criteria) was the most significant predictor of pregnancy (stepwise regression analysis, P = 0.003). Using logistic regression, morphology was the best predictor of pregnancy (r = 0.12); linearity of movement significantly enhanced the predictive value of morphology alone (r = 0.17, P = 0.004). Overall, the pregnancy rates were significantly higher (P = 0.01) in cases with > or = 14% normal morphology (15% per cycle) compared to cases with < 14% normal morphology (7% per cycle). This threshold level for morphology is in agreement with previously published IVF results. These results underscore the significance of sperm morphology assessed by strict criteria as a predictor of pregnancy outcome in the IUI setting.

Sperm morphology as diagnosed by strict criteria: probing the impact of teratozoospermia on fertilization rate and pregnancy outcome in a large in vitro fertilization population

OBJECTIVE

To investigate the predictive value of sperm morphology assessed by strict criteria on IVF outcome.

DESIGN

Retrospective analysis of all IVF cycles (January 1987 to December 1992).

MAIN OUTCOME MEASURES

All patients were assigned to one of three groups based on sperm morphology: P-pattern (< 4% normal forms), G-pattern (4% to 14% normal forms), and N-pattern (> 14% normal forms). Morphology pattern was related to other semen characteristics and IVF outcome.

RESULTS

Despite corrective measures at oocyte insemination, the fertilization rate was significantly different among the three morphology groups, P < G < N. N-pattern sperm produced a mean fertilization rate over 85% regardless of low motility or concentration. In a cohort study, P-pattern cycles produced a lower implantation rate and lower ongoing pregnancy rate, independent of the lower fertilization rate.

CONCLUSIONS

Strict morphology is an excellent biomarker of sperm fertilizing capacity, independent of motility and concentration. P-pattern sperm may denote a poorer prognosis for establishing a pregnancy, even after a satisfactory fertilization rate is achieved.

Enhancement of in vitro murine embryo development by recombinant leukemia inhibitory factor

OBJECTIVE

Human recombinant leukemia inhibitory factor (rLIF) has been shown to stimulate hatching of murine and ovine embryos in vitro. The temporal and dose-dependent effects of murine rLIF (mrLIF) and human rLIF (hrLIF) on embryo development in two different mouse strains were investigated in this work.

METHODS

Two-cell embryos were recovered from the fallopian tubes of superovulated/mated females and cultured in Krebs medium plus bovine serum albumin in microdroplets under oil.

RESULTS

In the B6CBF1 strain, mrLIF significantly stimulated blastocyst formation and decreased embryo fragmentation/degeneration when added simultaneously at the initiation of culture or 24 hours thereafter. Human rLIF also had a positive effect on development. In the CD1 strain (lower fecundity), mrLIF dose-dependent effects were observed, with enhanced developmental stimulation achieved with higher doses.

CONCLUSIONS

These findings confirm that hrLIF stimulates mouse embryo development in vitro and that different mouse strains show distinct responses to the cytokine. In addition, mrLIF enhances blastocyst formation and decreases embryo fragmentation when added to the embryo culture as early as the two-cell stage.

The YAG laser used in micromanipulation to transect the zona pellucida of hamster oocytes

PROBLEM

Since there has been no reported use of the YAG laser to micromanipulate oocytes, our purpose was to study whether (1) a YAG laser could be used to open the zona pellucida of hamster oocytes; (2) human sperm could reach the ooplasm and (3) under sperm penetration assay conditions, sperm would bind and penetrate the ooplasm.

RESULTS

A YAG 100 laser was used at 10 W and 0.4-sec pulse width to open eight of eight ooplasm oocytes. The opening in the zonae was 0.25 to 1.0 rad (10 to 40 microns). For the initial eight oocytes and two parallel controls, the coarse appearance of the ooplasm was unchanged after 3 days. Next, in 11 of 12 manipulated oocytes, the sperm clustered at the opening of the zona. When 16 more oocytes were opened and exposed to sperm in sperm penetration assay conditions, each ooplasm bound sperm. There was no penetration noted. Each manipulation time was < 1 min. To clarify the laser effect, oocytes were exposed to laser energy then utilized as the interactive surface in the sperm penetration assay. It was found that only 20% bound sperm with no penetration.

CONCLUSION

While the time factor compares favourably with other methods of zona opening, further study needs to be performed to minimize effect to the exposed oocyte.

Fertilization and mouse embryo development in the presence of midazolam

Mouse embryo in vitro development elucidates the effect of a pharmacologic agent on cellular differentiation. Midazolam provides conscious sedation for patients undergoing egg retrieval for in vitro fertilization and is found in patient follicular fluid. Mouse preimplantation embryo formation and development were evaluated in the presence of midazolam. Midazolam was cocultured with two-cell mouse preimplantation embryos over 72 h and injected systemically just before ovulation and coitus. Concentrations to 12.5 micrograms/mL displayed no significant toxic effects on in vitro two-cell-to-blastocyst development. Doses to 35.0 mg/kg did not prevent or impair in vivo fertilization. Midazolam has no adverse effect on in vitro development of two-cell-to-blastocyst-stage embryos nor on in vivo fertilization and cell division at concentrations approximating and exceeding those that ova are exposed to during clinical anesthesia. Midazolam is recommended for use to induce sedation in human in vitro fertilization where association with gametes and zygotes is probable.

Relationship between morphology and motion characteristics of human spermatozoa in semen and in the swim-up sperm fractions

In this study, the authors evaluated the morphology pattern and motion characteristics of human spermatozoa before and after swim-up separation. Samples were divided into two, morphologically different groups according to the percentage of normal sperm forms assessed by the strict criteria of the Norfolk laboratory: "good"(G) and "poor" (P) prognosis patterns. The percentages of normal forms, slightly abnormal forms, and severe head defects were significantly different in the two groups. Motile characteristics were analyzed by a computerized semen analyzer with constant parameter settings. Before swim-up there were no significant differences in semen volume, percentage of neck and tail defects, concentration, or percentage of motility and linearity, but the mean velocity was higher in group G. After swim-up the percentage of motility, total number of motile cells, and recovery rate were higher for group G, and the incidence of severe head defects correlated negatively with the percentage of cells with a velocity of greater than 80 microns/sec. The results suggest that patients with a high incidence of sperm head defects have impaired original velocity, and swim-up selects for velocity as well as normal forms and motility. Although motility and velocity improved substantially after swim-up, the recovery rate and percentage of motility were significantly lower in the P group.

Comparison of a discontinuous Percoll gradient method versus a swim-up method: effects on sperm morphology and other semen parameters

Increasing the proportion of motile and normal spermatozoa is an important objective for assisted reproductive procedures. The aim of this study was to compare the results of a Percoll and swim-up-method, especially on the sperm morphology. The Percoll technique gave a recovery rate of 81.3% of motile spermatozoa against a recovery rate of 28.98% for the swim-up technique. When the percentage of normal spermatozoa was also brought into calculation the recovery rate with the Percoll technique decreased to 62.03% and increased to 31.81% for the swim-up technique. This was due to a decrease in the resultant morphology of the Percoll technique to a median of 8.0% and an increase to 11.5% for the swim-up technique from a median of 10.5% of the original samples.

Hypoosmotic swelling test in the prediction of male fertility

The hypoosmotic swelling test (HOS) is a simple test to measure the functional competence of human sperm membranes. The question is, does a relationship exist between this competence and the fertilization potential of human spermatozoa? In this study the strongest correlation (r = 0.76) was obtained between sperm swelling and sperm viability (supravital staining). Only a moderate correlation (r = 0.50) was obtained with normal sperm morphology; weaker correlations were also obtained with the sperm penetration assay (r = 0.42) and human IVF (r = 0.24). The results, therefore, indicate that the HOS test has a limited predictive value. Notwithstanding this low concordance between sperm swelling and fertilizing potential, a less than 50% HOS test threshold was seen to be a definite indicator of a male factor.

Usefulness of sperm penetration assay in fertility predictions

The competence of the sperm penetration assay (SPA) to predict male fertility, as determined by normal sperm morphology and the fertilizing potential, as shown by human in vitro fertilization (IVF), was investigated. A significant correlation was obtained between normal sperm morphology and the SPA (phi = 0.623). A weaker correlation was however obtained with human IVF (phi = 0.397). Notwithstanding this weak association, a positive SPA (greater than 10%) was highly predictive (95%) of human IVF success. In contrast, a negative SPA (less than or equal to 10%) was associated with a high rate of false-negatives (65%). The SPA does however warn that a male factor may be present, as the mean fertilization rate of this group of patients was markedly reduced. The preincubation period for the spermatozoa did not play a major role in the predictive ability of a SPA outcome.

Corrective measures and pregnancy outcome in in vitro fertilization in patients with severe sperm morphology abnormalities

Sperm morphology evaluated by new, strict criteria is a good predictor of outcome in in vitro fertilization (IVF). This study aimed (1) to determine whether the fertilization rate of preovulatory oocytes in patients with abnormal morphology can be improved by increasing insemination concentration at the time of IVF and (2) to evaluate the pregnancy outcome in patients with abnormal sperm morphology. Three groups were studied: (1) normal morphology, (2) good prognosis pattern, and (3) poor prognosis pattern. All other sperm parameters were normal. Group 3 had a lower overall fertilization rate, lower pregnancy rate/cycle, and lower ongoing pregnancy rate/cycle. Groups 2 and 3 showed a higher miscarriage rate, although not significantly different from group 1. By increasing insemination concentration from 2- to 10-fold, the fertilization rate in group 3 increased from 14.5% to 62.6%. However, pregnancy outcome did not improve. We conclude that patients with severe sperm head abnormalities have a lower ability to establish successful pregnancies, even though fertilization may be achieved.

Mouse embryo quality control for toxicity determination in the Norfolk in vitro fertilization program

Ongoing quality control is necessary as part of the maintenance and improvement of a successful human in vitro fertilization (IVF) program. Using a mouse quality-control culture system, several instrument preparation protocols were reevaluated to determine their efficiency in the control or elimination of potential toxicity. Dilute concentrations of urine and endometrial fluid were also tested. Medium rinsed through laparoscope and aspiration needles failed to support embryo development. This effect was reversed in needles that were pretreated with rinses of Dulbecco's phosphate-buffered saline. Endometrial fluid demonstrated no obvious toxic effect, but urine-exposed embryos arrested in the two-cell state. The importance of periodic evaluation of materials and their pretreatment before use in in vitro fertilization of human oocytes is essential to ensure control of potentially toxic substances.

Evaluation of semen parameters by means of automated sperm motion analyzers

Fresh semen specimens from 46 patients and donors were evaluated for concentration, motility, velocity, and linearity using two different commercially available computerized sperm motion analyzer systems. Although no significant differences in measurement of concentration or motility were observed, significant differences in velocity and linearity were recorded. Fourteen cryopreserved/thawed samples were assessed with the same set-up parameters as fresh specimens. When discrepancies between manual and computer counts were noted, the authors changed the set-up parameters and evaluated 33 additional specimens. Again, no differences in concentration and motility, but significant differences in velocity and linearity were observed. Interlaboratory results must be correlated and standardization of set-up parameters of various analyzers is essential.

Abnormal sperm morphology and other semen parameters related to the outcome of the hamster oocyte human sperm penetration assay

A new method for evaluation of sperm morphology using strict criteria is currently used in the andrology laboratory at the Eastern Virginia Medical School. A prospective study was designed to evaluate the following semen parameters in samples of all patients over a set period of time: sperm concentration and motility, and normal sperm morphology. These factors were correlated with results of the hamster zona-free oocyte/human sperm penetration assay (SPA). One hundred patients with a sperm concentration ranging from 2 to 219 X 10(6)/ml, a motile sperm fraction ranging from 6.9 to 87%, and normal sperm morphology ranging from 1 to 39%, were evaluated. The statistical analysis system general linear model was used to judge the influence of the different variables. There was a statistically significant relationship between the per cent of sperm with normal morphology and penetration rate in the SPA (P = 0.001). Outcome of the SPA was also correlated with in vitro fertilization, retrospectively, in 84 patients. Thirty-eight patients had an SPA less than 10%, with no fertilization in vitro in 13 patients (33.3%) and fertilization in 25 (66.7%). Forty-five had an SPA greater than 10% with fertilization in 37 (82.2%) and no fertilization in eight (17.8%) patients.

Extravasation. A serious complication of the split-sheath introducer technique for venous access

The use of split-sheath introducers to place venous access catheters results in the potential for subcutaneous extravasation and tissue injury or necrosis. We present six cases that demonstrate this complication and illustrate the probable mechanism. The safe use of these catheters requires verification that blood can be aspirated from the catheter and a high index of suspicion for extravasation when symptoms develop.

Correlation between sperm morphology, acrosin, and fertilization in an IVF program

Acrosin, a neutral proteinase, is located within the acrosome. The aim of this study was to evaluate acrosin concentrations in patients with severe damage of the sperm head and to determine whether acrosin concentration could predict the chances of fertilization in an IVF program. Sixty patients were accepted into this study, prospectively. The patients were divided into two groups, those with a normal morphology of less than 14% (group I, n = 33) and those with normal morphology less than 14% (group II, n = 27). All patients had a sperm concentration of less than 20 million sperm/ml and less than 30% progressively motile sperm. The acrosin assays were performed on the semen sample obtained on the day of IVF. Routine IVF insemination procedures were used, and only mature oocytes were considered. The only factor that showed a significant correlation of fertilization was normal morphology (p less that 0.01). The mean acrosin level was 73.4 /+- 38.6 mED/10 million sperm in group I and 70.9 /+- 42.7 mIU/10 million sperm in group II (no significant difference). The fertilization rate in group I was 45.4% and in group II, 77.7% p less than 0.002). Acrosin levels were not significantly different in patients with and without fertilization (72.0 /+- 42.1 and 73.6 /+- mIU/10 million sperm, respectively).

Predictive value of abnormal sperm morphology in in vitro fertilization

In patients with acceptable sperm count and motility, two patterns of abnormal morphology, judged with strict criteria, were identified and described. Patients with less than 4% normal forms and less than 30% morphology index (summation of normal and slightly amorphous forms) had a fertilization rate of 7.6% of the oocytes (P pattern, poor prognosis). Patients with normal morphology between 4 and 14% had a significantly better fertilization rate of 63.9% of the oocytes (P less than 0.0001). Cases with greater than 14% normal forms fertilized within the normal range for the laboratory. By evaluating sperm morphology with the proposed strict criteria, its predictive value in in vitro fertilization is enhanced.

New method of evaluating sperm morphology with predictive value for human in vitro fertilization

A prospective study was planned to evaluate sperm morphology as a parameter to predict the fertilization outcome in an in vitro fertilization program. Couples applying to in vitro fertilization were admitted into this project when the sperm concentration was greater than 20 million per mL and motility greater than 30 per cent. Based on new strict criteria for evaluating normal sperm morphology, patients were divided prospectively into 2 groups. In group I (25 patients) normal sperm morphology was less than 14 per cent, and in group II (71 patients) normal sperm morphology was greater than 14 per cent, using a threshold established previously. Multiple regression analysis was used to evaluate different parameters: concentration, motility, and morphology against the dependent variables, fertilization, and cleavage. The only factor which was significantly correlated with fertilization and cleavage was normal sperm morphology (P less than 0.0001). The fertilization rate (per oocyte) and the cleavage rate were 49.4 per cent and 47.6 per cent in group I and 88.3 per cent and 87 per cent in group II (P less than 0.0001). The ongoing pregnancy rate per laparoscopy and per embryo transfer was 4 per cent and 5.5 per cent, respectively, in group I and 18.3 per cent and 18.5 per cent, respectively, in group II (no significant difference). This study demonstrates the value of analyzing sperm morphology using the criteria recommended in terms of predicting fertilization and perhaps pregnancy outcome. Patients can be better counseled and the probability of fertilization or no fertilization can be more accurately established. Furthermore a trend is shown in the pregnancy rate that may indicate the importance of the male genome in establishing a pregnancy.

A quick, reliable staining technique for human sperm morphology

The evaluation of sperm morphology is still an important parameter in the diagnosis of the infertile male. Most techniques used for staining human sperm are very time-consuming. A routine stain used for determining differential count of leucocytes (Diff-Quik stain) was evaluated against the standard Papanicolaou stain. Morphology results from 20 duplicate semen smears using both staining methods were determined separately by 2 technicians using a blind protocol. No significant differences were observed when comparing the two staining methods (paired Student's t-test). The advantages of the Diff-Quik stain are: a) complete staining-to-reading time under 7 min, b) commercially prepared reagents, and c) case of staining procedure.

Toxicity testing for human in vitro fertilization programs

Using a mouse embryo culture system, several procedures and materials associated with human in vitro fertilization protocols were tested for potential toxicity. Also, quality-control assays were performed for media prepared by nine different human in vitro fertilization programs. Detrimental effects upon embryo development were observed when culture media were exposed to the following substances: surgical instruments sterilized with Cidex or Cidex-7 or sterilized with ethylene oxide after packaging in Nest Protector Packs, various brands of surgical gloves, and various synthetic materials being evaluated as possible needle or catheter "liners." Results from comparative testing of media and serum supplements prepared by different in vitro programs indicated a wide range in culture medium quality, as assayed by the ability of the reagents to support mouse embryo development. The importance of an animal model system available to all human in vitro programs for routine quality-control analysis and testing of novel uses of materials and innovative methods is discussed.