Biomechanical evaluation of a novel biomimetic artificial intervertebral disc in canine cervical cadaveric spines.

Background Context: Cervical disc replacement (CDR) aims to restore motion of the treated level to reduce the risk of adjacent segment disease (ASD) compared with spinal fusion. However, first-generation articulating devices are unable to mimic the complex deformation kinematics of a natural disc. Thus, a biomimetic artificial intervertebral CDR (bioAID), containing a hydroxyethylmethacrylate (HEMA)-sodium methacrylate (NaMA) hydrogel core representing the nucleus pulposus, an ultra-high-molecular-weight-polyethylene fiber jacket as annulus fibrosus, and titanium endplates with pins for primary mechanical fixation, was developed. Purpose: To assess the initial biomechanical effect of the bioAID on the kinematic behavior of the canine spine, an ex vivo biomechanical study in 6-degrees-of-freedom was performed. Study Design: A canine cadaveric biomechanical study. Methods: Six cadaveric canine specimens (C3-C6) were tested in flexion-extension (FE), lateral bending (LB) axial rotation (AR) using a spine tester in three conditions: intact, after C4-C5 disc replacement with bioAID, and after C4-C5 interbody fusion. A hybrid protocol was used where first the intact spines were subjected to a pure moment of ±1 Nm, whereafter the treated spines were subjected to the full range of motion (ROM) of the intact condition. 3D segmental motions at all levels were measured while recording the reaction torsion. Biomechanical parameters studied included ROM, neutral zone (NZ), and intradiscal pressure (IDP) at the adjacent cranial level (C3-C4). Results: The bioAID retained the sigmoid shape of the moment-rotation curves with a NZ similar to the intact condition in LB and FE. Additionally, the normalized ROMs at the bioAID-treated level were statistically equivalent to intact during FE and AR while slightly decreased in LB. At the two adjacent levels, ROMs showed similar values for the intact compared to the bioAID for FE and AR and an increase in LB. In contrast, levels adjacent to the fused segment showed an increased motion in FE and LB as compensation for the loss of motion at the treated level. The IDP at the adjacent C3-C4 level after implantation of bioAID was close to intact values. After fusion, increased IDP was found compared with intact but did not reach statistical significance. Conclusion: This study indicates that the bioAID can mimic the kinematic behavior of the replaced intervertebral disc and preserves that for the adjacent levels better than fusion. As a result, CDR using the novel bioAID is a promising alternative treatment for replacing severely degenerated intervertebral discs.

Mechanical characterization of a novel biomimetic artificial disc for the cervical spine.

A novel biomimetic artificial intervertebral disc (bioAID) replacement implant has been developed containing a swelling hydrogel representing the nucleus pulposus, a tensile strong fiber jacket as annulus fibrosus and titanium endplates with pins to primarily secure the device between the vertebral bodies. In this study, the design safety of this novel implant was evaluated based on several biomechanical parameters, namely compressive strength, shear-compressive strength, risk of subsidence and device expulsion as well as identifying the diurnal creep-recovery characteristics of the device. The bioAID remained intact up to 1 kN under static axial compression and only 0.4 mm of translation was observed under a compressive shear load of 20 N. No subsidence was observed after 0.5 million cycles of sinusoidal compressive loading between 50 and 225 N. After applying 400 N in antero-posterior direction under 100 N axial compressive preload, approximately 2 mm displacement was found, being within the range of displacements reported for other commercially available cervical disc replacement devices. The diurnal creep recovery behavior of the bioAID closely resembled what has been reported for natural intervertebral discs in literature. Overall, these results indicate that the current design can withstand (shear-compression loads and is able to remain fixed in a mechanical design resembling the vertebral bodies. Moreover, it is one of the first implants that can closely mimic the poroelastic and viscoelastic behavior of natural disc under a diurnal loading pattern.

Synovial membrane-derived mesenchymal progenitor cells from osteoarthritic joints in dogs possess lower chondrogenic-, and higher osteogenic capacity compared to normal joints.

BACKGROUND: Synovial membrane-derived mesenchymal progenitor cells (SM-MPCs) are a promising candidate for the cell-based treatment of osteoarthritis (OA) considering their in vitro and in vivo capacity for cartilage repair. However, the OA environment may adversely impact their regenerative capacity. There are no studies for canine (c)SM-MPCs that compare normal to OA SM-MPCs, even though dogs are considered a relevant animal model for OA. Therefore, this study compared cSM-MPCs from normal and OA synovial membrane tissue to elucidate the effect of the OA environment on MPC numbers, indicated by CD marker profile and colony-forming unit (CFU) capacity, and the impact of the OA niche on tri-lineage differentiation. METHODS: Normal and OA synovial membrane were collected from the knee joints of healthy dogs and dogs with rupture of the cruciate ligaments. The synovium was assessed by histopathological OARSI scoring and by RT-qPCR for inflammation/synovitis-related markers. The presence of cSM-MPCs in the native tissue was further characterized with flow cytometry, RT-qPCR, and immunohistochemistry, using the MPC markers; CD90, CD73, CD44, CD271, and CD34. Furthermore, cells isolated upon enzymatic digestion were characterized by CFU capacity, and a population doublings assay. cSM-MPCs were selected based on plastic adherence, expanded to passage 2, and evaluated for the expression of MPC-related surface markers and tri-lineage differentiation capacity. RESULTS: Synovial tissue collected from the OA joints had a significantly higher OARSI score compared to normal joints, and significantly upregulated inflammation/synovitis markers S100A8/9, IL6, IL8, and CCL2. Both normal and OA synovial membrane contained cells displaying MPC properties, including a fibroblast-like morphology, CFU capacity, and maintained MPC marker expression over time during expansion. However, OA cSM-MPCs were unable to differentiate towards the chondrogenic lineage and had low adipogenic capacity in contrast to normal cSM-MPCs, whereas they possessed a higher osteogenic capacity. Furthermore, the OA synovial membrane contained significantly lower percentages of CD90+, CD44+, CD34+, and CD271+ cells. CONCLUSIONS: The OA environment had adverse effects on the regenerative potential of cSM-MPCs, corroborated by decreased CFU, population doubling, and chondrogenic capacity compared to normal cSM-MPCs. OA cSM-MPCs may be a less optimal candidate for the cell-based treatment of OA than normal cSM-MPCs.

Atomic structure of an FeCrMoCBY metallic glass revealed by high energy x-ray diffraction.

Amorphous bulk metallic glasses with the composition Fe48Cr15Mo14C15B6Y2have been of interest due to their special mechanical and electronic properties, including corrosion resistance, high yield-strength, large elasticity, catalytic performance, and soft ferromagnetism. Here, we apply a reverse Monte Carlo technique to unravel the atomic structure of these glasses. The pair-distribution functions for various atomic pairs are computed based on the high-energy x-ray diffraction data we have taken from an amorphous sample. Monte Carlo cycles are used to move the atomic positions until the model reproduces the experimental pair-distribution function. The resulting fitted model is consistent with ourab initiosimulations of the metallic glass. Our study contributes to the understanding of functional properties of Fe-based bulk metallic glasses driven by disorder effects.

Atomic arrangements in an amorphous CoFeB ribbon extracted via an analysis of radial distribution functions.

We discuss the atomic structure of amorphous ferromagnetic FeCoB alloys, which are used widely in spintronics applications. Specifically, we obtain the pair-distribution functions for various atomic pairs based on high-energy x-ray diffraction data taken from an amorphous Co20Fe61B19specimen. We start our reverse Monte Carlo cycles to determine the disordered structure with a two-phase model in which a small amount of cobalt is mixed with Fe23B6as a second phase. The structure of the alloy is found to be heterogeneous, where the boron atoms drive disorder through the random occupation of the atomic network. Our analysis also indicates the presence of small cobalt clusters that are embedded in the iron matrix and percolating the latter throughout the structure. This morphology can explain the enhanced spin polarization observed in amorphous magnetic materials.

Cyclic fatigue resistance and shaping ability of heat-treated nickel-titanium instruments after repeated use.

AIMS: To evaluate the effect of multiple-use and sterilization on cyclic fatigue and shaping ability of heat-treated nickel-titanium (NiTi) rotary instruments. METHODS: A total of 120 acrylic blocks with S-shaped canals were photographed and prepared by HyFlex CM, ProTaper Next, and Twisted File. Ten new sets of each rotary instruments were used for four times. The autoclaving process was repeated after each use. Pre- and post instrumentation images were superimposed. The amount of resin removal and canal transportation by each system was measured in eleven different points. Instruments were subsequently subjected to a cyclic fatigue test in a double-curved artificial canal. The means and standard deviations of the number of cycles to failure (NCF) were calculated and statistically analyzed (P < 0.05). RESULTS: No fractures occurred during the shaping of the simulated canals. The ProTaper Next removed the greatest amount of resin, whereas the Twisted File had the lowest values at all levels. Repeated clinical use and sterilization resulted in a decrease in the resin removal at most levels in Twisted File and ProTaper Next. In terms of canal transportation, an increase in a limited number of levels was detected after repeated use of all rotary files. Twisted File had the greatest cyclic fatigue resistance, followed by HyFlex CM and ProTaper Next (P < 0.05). CONCLUSIONS: The effects of repeated use and autoclaving on the cyclic fatigue resistance of HyFlex CM, ProTaper Next, and Twisted File were not significant. Canal transportation increased mostly in the apical region. The amount of resin removal decreased as the number of use increased for ProTaper Next and Twisted File instruments.

Can intraoperative endoscopy prevent esophagojejunal anastomotic leakage after total gastrectomy?

BACKGROUND: Esophagojejunostomy (EJ) is frequently performed after total gastrectomy for proximal gastric tumors. Despite evolving surgical techniques and improving perioperative care, the EJ leak is one of the most severe life-threatening complications. This study investigated the preventability of postoperative anastomotic complications by performing intraoperative endoscopy. METHODS: We included 86 patients who underwent total gastrectomy and Roux-en-Y esophagojejunostomy anastomosis in the study. Patients were divided into two groups and analyzed retrospectively. Group 1 consisted of 43 patients who did not undergo intraoperative endoscopy between 2017 and 2019, and Group 2 included 43 patients who underwent intraoperative endoscopy between 2019 and 2020. RESULTS: Esophagojejunostomy anastomotic leak (EAL) was observed in 2.3 % of patients in Group 1 but not in Group 2. Anastomosis-related abnormal findings (anastomotic defect, bleeding, air leak, mucosal separation) were recorded in seven patients of Group 2 during endoscopy. When such findings were observed, additional full-thickness sutures were placed on the anastomosis line and strengthened. Complication related to anastomosis was not observed in the postoperative period in Group 2. DISCUSSION: After a total gastrectomy, the most severe complication affecting mortality, morbidity, and consequently the cost of the disease is esophagojejunal anastomotic leakage. Most of these complications are induced by technical errors not noticed during surgery. The crucial advantage of performing intraoperative endoscopy is the technically detailed evaluation of anastomosis. CONCLUSION: Intraoperative endoscopy is a safe method to evaluate the strength of anastomosis. This procedure provides detailed information regarding anastomotic integrity. HIPPOKRATIA 2021, 25 (3):108-112.

Magnetic properties of γ-Fe2O3 nanoparticles in a porous SiO2 shell for drug delivery.

A method is presented for synthesizing core-shell nanoparticles with a magnetic core and a porous shell suitable for drug delivery and other medical applications. The core contains multiple γ-Fe2O3 nanoparticles (∼15 nm) enclosed in a SiO2 (∼100-200 nm) matrix using either methyl (denoted TMOS-γ-Fe2O3) or ethyl (TEOS-γ-Fe2O3) template groups. Low-temperature Mössbauer spectroscopy showed that the magnetic nanoparticles have the maghemite structure, γ-Fe2O3, with all the vacancies in the octahedral sites. Saturation magnetization measurements revealed that the density of γ-Fe2O3 was greater in the TMOS-γ-Fe2O3 nanoparticles than TEOS-γ-Fe2O3 nanoparticles, presumably because of the smaller methyl group. Magnetization measurements showed that the blocking temperature is around room temperature for the TMOS-γ-Fe2O3 and around 250 K for the TEOS-γ-Fe2O3. Three dimensional topography analysis shows clearly that the magnetic nanoparticles are not only at the surface but have penetrated deep in the silica to form the core-shell structure.

Size-dependent magnetic properties of γ-Fe2O3 nanocrystallites.

A route for synthesizing monodisperse magnetic nanocrystallites of maghemite, [Formula: see text]-Fe2O3, with various sizes has been revisited. A systematic investigation of three [Formula: see text]-Fe2O3 nanocrystalline samples by different techniques has been performed to characterize their size-dependent magnetic properties. Zero-field-cooled and field-cooled magnetization measurements reveal that the superparamagnetic blocking temperatures are around 230 K, 170 K, and 50 K for the 15.0 nm, 11.8 nm, and 6.1 nm nanocrystallites, respectively. Low-temperature Mössbauer spectra show that all three nanocrystallites have the maghemite structure with all the vacancies in the B-sites. Furthermore, detailed analysis shows that there are more vacancies on the B-sites for the 6.1 nm nanocrystallites compared to 0.33 for the bulk maghemite.

Histopathological changes in the upper digestive tract of pigeons infected with Hadjelia truncata.

Thirty-five pigeons from ten different farms in Fars area, southern Iran were submitted for post mortem inspection. Based on the clinical observations and gross pathological examinations, all the birds showed severe weight loss, diarrhea and to some extent ventricular enlargement. Furthermore, all the cases demonstrated large numbers of nematodes attached to the mucosa and submucosa of the ventriculus. Parasitological examinations revealed that the recovered parasites were Hadjelia truncata. The histopathological changes showed necrosis of the mucosal cells with moderate infiltration of lymphocytes, macrophages, heterophils and eosinophils in the lamina properia and muscularis mucosa in the infected animals. Based on the parasitological and pathological findings it can be concluded that the nematode H. truncate could be assigned as a pathogenic agent in the upper tract of pigeons.

Metabolic syndrome is not only a risk factor for cardiovascular diseases in systemic lupus erythematosus but is also associated with cumulative organ damage: a cross-sectional analysis of 311 patients.

BACKGROUND/PURPOSE: Patients with systemic lupus erythematosus (SLE) have increased rates of cardiovascular disease (CVD) that are one of the major causes of mortality. The aim of this study was to determine the frequencies of metabolic syndrome (MetS) and CVD in SLE patients and investigate the link between these and clinical features of SLE. METHODS: A total of 311 SLE patients were consecutively assessed for cumulative organ damage (SDI/SLICC scores), history of CVD and MetS as defined by the National Cholesterol Educational Program Adult Treatment Panel III (NCEP ATP III). Clinical data of SLE patients were collected from the records. RESULTS: The mean age of the patients was 40.2 ± 13.4 years and 89% were female. The frequencies of CVD and MetS were 15.2% and 19%, respectively. In this SLE cohort increased age, cumulative damage, disease duration and CVD were associated with MetS. CVD was associated with disease duration, cumulative damage, pericarditis, hematologic involvement, lymphopenia, thrombocytopenia, neurological involvement and antiphospholipid antibody (aPL) positivity. Hydroxychloroquine (HCQ) use was found as a protective factor for CVD. CONCLUSION: In SLE patients, MetS was associated with CVD and both increased with disease duration. Patients who developed MetS and/or CVD had increased cumulative organ damage. Certain clinical features of SLE and the presence of aPL were also associated with CVD. There was a significant protective effect of HCQ from CVD. The prevention of MetS and long-term use of HCQ may be beneficial in improving the prognosis of SLE.

Extracting the cation distributions in NiFe2-xAlxO4 solid solutions using magnetic Compton scattering.

We discuss the ground state electronic structure and magnetization properties of a series of NiFe2-x Al x O4 solid solutions (x = 0.0, 0.4, 0.8, 1.2, 1.6, and 2.0) using magnetic Compton scattering measurements, together with parallel first-principles computations. In this way, we systematically extract the complicated cation distributions in this ferrite system as a function of x. The relationship between the electronic ground state, magnetism, and cation distributions is explained in terms of a model, validated by our first-principles computations, wherein the magnetic properties of the three cation distributions are assumed to be different. A good accord is found between the computed and measured magnetic Compton profiles.

Controlling spin polarized band-structure by variation of vacancy intensity in nanostructures.

In this study, the magnetic properties of FeAl alloys with different grain sizes produced by high-pressure torsion were probed by means of magnetic Compton scattering. The measurements were performed at 300 and 10 K. Magnetic Compton profiles of nanocrystalline (35 nm) and ultrafine-grained (160 nm) FeAl alloys were analyzed in terms of the integral area, the width, and the distinctive dip intensity at low momenta. The changes in total magnetic moment and the strength of spin-polarization of itinerant electrons are assumed to be caused by vacancies induced during the preparation of the samples. Despite local disordering due to interfacial regions and deviations in perfect stoichiometry for B2 structure, the effect of vacancies is considered as the major magnetic state contributor.

Favourable pregnancy outcome in Takayasu arteritis: a single-centre experience.

OBJECTIVES: Takayasu arteritis is a chronic large-vessel vasculitis in young women of reproductive age. We aimed to obtain information on pregnancy in TA retrospectively. METHODS: Takayasu arteritis patients with history of pregnancy were included in this study. The evaluations included physical findings, serum C-reactive protein, erythrocyte sedimentation rate as well as history and symptoms. Information about pregnancies, abortus, deliveries and newborns was obtained from medical records. Disease activity score, disease damage index appraised Kerr's criteria and vasculitis damage index (VDI) and medication were recorded. RESULTS: Thirty-six Takayasu arteritis patients who had a total of 84 pregnancies were evaluated. The mean age of patients ranged 24.5 ± 6.6 years. Subclavian arteries (86%) were the most frequently involved vessels. We were able to complete the follow-up of ten patients who had a pregnancy after diagnosis during the period of pregnancy. Two patients who had renal artery involvement and active disease in third trimester suffered from preeclampsia and a worsening of hypertension. In one of them, disease flared up in the third trimester. There was no active disease in the postpartum sixth month. Maternal heart failure, cerebrovascular accident, death or cerebral hypoperfusion at the time of delivery, asphyxia and newborn anomalies were not seen in any of these patients. CONCLUSIONS: TA pregnancies may have a favourable outcome with regular follow-up schedule and close monitorisation of blood pressure.

Frequency of Celiac Disease in Children with Beta Thalassemia major.

BACKGROUND: We aimed to investigate the frequency of celiac disease in children with ß-thalassemia major (B-TM) in Shiraz, southern Iran. MATERIALS AND METHODS: In this study, the prevalence of celiac disease in children with B-TM was evaluated. Children with B-TM were screened for celiac disease by ant-tissue transglutaminase (anti-tTG) IgA antibody, IgA level and anti-tTG IgG. A total of 1500 school healthy children in Shiraz with age/sex matched were selected as control group. RESULTS: A total of 215 B-TM patients with mean age of 12.7 ± 4.4 years, were included into the study (52.1% was male). None of the patients were positive for anti-tTG IgA. Eight cases were IgA deficient in whom anti-tTG IgG was investigated but none of them were positive for anti-tTG IgG. The finding in control group has a seroprevalence of 2% and biopsy proven disease of 0.6%. CONCLUSION: Many patients with thalassemia major have multiple non specific symptom that are not justifiable with underlying disease and might be due to atypical celiac disease. We didn't find any case of celiac disease among more than 200 children with ß-thalassemia major in Shiraz, southern Iran. So it seems reasonable to screen only those who have features, even not classical, of celiac disease.

Use of ductoscopy as an additional diagnostic method and its applications in nipple discharge.

AIM: About 1/10 of the patients apply to breast clinics with the complaint of nipple discharge (ND). Surgery is the most frequently preferred treatment method in case of suspicious ND. The contribution of ductoscopy to identify the patients who are candidates for surgery was evaluated and its role to limit the surgery was assessed. METHODS: From November 2005 to December 2010 430 patients with ND were assessed by 456 ductoscopic investigations and the results were analyzed. Complete ductoscopic evaluation was achieved in 84% of cases and 28 patients were offered surgery but did not accept (N.=355). Patients with bloody or serous discharges from a single duct were investigated by ductoscopy under local anesthesia as an office procedure. The patients were grouped according to discharge characteristics and the ductoscopic diagnoses. RESULTS: A total of 223 patients had all three criteria of pathologic ND (PND: single duct, spontaneous and bloody/serous discharge). Twenty-two potential neoplastic or malignant lesion (PNML) and 79 papillomatous lesion (solitary or multiple papilloma) were identified. In 132 patients with just two of the PND criteria, 5 PNML and 18 papillomatous lesions were identified. Twenty-three patients with solitary papilloma that were removed by ductoscopic papillomectomy (DP) are followed up without surgery. CONCLUSION: Ductoscopy helped to identify the patients who required surgical treatment and decreased the number of operations. DP was successfully performed in select group of patients who otherwise would have required surgical resection. Patients with normal ductoscopy findings and patients who were treated with DP successfully can be followed up without the need of surgery.

Oxidation states and quality of upper interfaces in magnetic tunnel junctions: oxygen effect on crystallization of interfaces.

In this study, we have deposited an 57Fe sensor layer at the upper interface, i.e. the interface between the oxide barrier and the upper electrode in selected magnetic tunnel junctions (MTJs), in order to perform nuclear resonant scattering with the aim of obtaining direct information on the magnetic properties and quality of this interface. This is a unique approach as it makes use of this powerful technique to give information at the atomic level, and specifically from the interface where the sensor layer is deposited. By varying sample tunnel barrier thicknesses and oxidation times in the preparation of this barrier, we have observed that longer oxidation time results in not only an increase of the magnetic hyperfine fields, but also causes an interesting crystallization and smoothing of the interface. We also observed that boron atoms diffuse away from the lower part of the upper FeCoB electrode toward the capping layer. An important observation, which has a crucial effect in tunnel magnetoresistance values, is the absence of any magnetically dead FeO layer at the interface. Another finding is that the deposition of Fe on MgO is much smoother than the deposition of MgO on Fe.

Oxidation states and the quality of lower interfaces in magnetic tunnel junctions: oxygen effect on crystallization of interfaces.

Lower interfaces in magnetic tunnel junctions (MTJs), which are the basic components in many spintronic devices such as magnetoresistive random access memories, have crucial effects on the performance of these devices. To obtain more insight into such interfaces, we have introduced an ultrathin sensor layer of (57)Fe at the interface between the lower electrode and the oxide barrier in selected MTJs. This allowed us to perform nuclear resonant scattering measurements, which provide direct information on the magnetic properties and quality of the interfaces. The application of nuclear resonant scattering to study interfaces in MTJs is a unique approach in the sense that it gives information at the atomic level, and specifically from the interface where the sensor layer is deposited. Samples with different tunnel barrier thicknesses and varied oxidation times in the preparation of this barrier have been studied. These show that oxidation can not only increase the magnetic hyperfine fields but also cause an interesting smoothing and crystallizing of the interface. Another interesting finding is the observation of boron diffusion into the lower part of the FeCoB lower electrode towards the Ta seed layer.

A randomized, placebo controlled study: EMLA in minor breast surgery.

AIM: Patients undergoing excision for breast lumps prefer general anesthesia or local anesthesia plus sedation, because of the fear of pain for local anesthesia alone. The aim of this study is to show the efficacy of an eutectic mixture of local anesthetic lignocaine and prilocaine (EMLA®) in these patients. METHODS: This study has been designed randomized, placebo-controlled. Forty five patients undergoing excision for breast lumps were divided into three groups. The first group was administered local EMLA cream preoperatively (Group I, N.=15), the second group (Group II, N.=15) had no preoperative preparation and the third group was placebo group (Group III, N.=15). All groups underwent the operation under local anesthesia. Pain during the local anesthesia and three hours after the operation were assessed using the visual analog scale. The amount of local anesthetic used during the operation and the anesthetic need of patients after the operation were assessed. RESULTS: When the three groups were compared, it was found that the intensity of pain in the group with EMLA was considerably lower during and after the operation (P<0.05). The amount of local anesthetic used during the operation was lower (P<0.05) and the need for post-operative analgesic was also less than the usual (P<0.05). CONCLUSION: Topical EMLA use decreases the pain, provides per-operative and postoperative patient and physician comfort, improved patient's compliance, and simplifies the surgical procedure. This is the first study demonstrating that a topical anesthetic provides a non-invasive analgesia during benign breast mass excision.

Magnetic and interface properties of Fe(0.82)Ni(0.18)/Co(001) superlattices.

The thickness dependence of the Fe magnetic hyperfine field and the interfacial intermixing of Fe(0.82)Ni(0.18)/Co superlattices, with the same thickness for FeNi and Co layers, have been investigated. A local concentration model using the magnetic hyperfine field values from the [Fe(0.82)Ni(0.18)](1 - x)Co(x) alloys has been used to interpret the field distribution in the superlattices and the Co concentration profiles over the superlattices. A relationship between the Fe magnetic hyperfine field and the Fe magnetic moment has been determined for the unordered [Fe(0.82)Ni(0.18)](1 - x)Co(x) and Fe(1 - x)Co(x) alloys. The magnetic hyperfine fields have been explained using two Fermi contact terms: (i) the core electron term proportional to the Fe magnetic moment with a proportionality constant of - 13 T/µ(B) and (ii) a valence electron term linearly dependent on the Co concentration. The direction of the magnetic moments is found to be in the sample plane except for the 1/1 superlattice, where an angle of about 45° is found.