The association of body composition on chemotherapy toxicities in non-metastatic colorectal cancer patients: a systematic review

BACKGROUND

In recent years, certain body composition measures, assessed by computed tomography (CT), have been found to be associated with chemotherapy toxicities. This review aims to explore available data on the relationship between skeletal muscle and adiposity, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), intramuscular and intermuscular adipose tissue and their association with chemotherapy toxicity in non-metastatic colorectal cancer (CRC) patients.

METHODS

A systematic literature search following PRISMA guidelines was conducted in Medline, Embase, Cochrane and Web of Science, for papers published between 2011 and 2023. The search strategy combined keywords and MESH terms relevant to 'body composition', 'chemotherapy toxicities', and 'non-metastatic colorectal cancer'.

RESULTS

Out of 3868 studies identified, six retrospective studies fulfilled the inclusion criteria with 1024 eligible patients. Low skeletal muscle mass was strongly associated with increased incidence of both chemotherapy toxicities and dose-limiting toxicity (DLT). The association of VAT, intramuscular and intermuscular adiposity was heterogeneous and inconclusive. There was no association between SAT and chemotherapy intolerance. No universal definitions or cut-offs for sarcopenia and obesity were noted. All studies utilized 2-dimensional (2D) CT slices for CT body composition assessment with varied selection on the vertebral landmark and inconsistent reporting of tissue-defining Hounsfield unit (HU) measurements.

CONCLUSION

Low skeletal muscle is associated with chemotherapy toxicities in non-metastatic CRC. However, quality evidence on the role of adiposity is limited and heterogeneous. More studies are needed to confirm these associations with an emphasis on a more coherent body composition definition and an approach to its assessment, especially regarding sarcopenia.

Observation of high-energy neutrinos from the Galactic plane

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos. We searched for neutrino emission using machine learning techniques applied to 10 years of data from the IceCube Neutrino Observatory. By comparing diffuse emission models to a background-only hypothesis, we identified neutrino emission from the Galactic plane at the 4.5σ level of significance. The signal is consistent with diffuse emission of neutrinos from the Milky Way but could also arise from a population of unresolved point sources.

Evidence for neutrino emission from the nearby active galaxy NGC 1068

A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy’s active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of 79 − 20 + 22 neutrinos at tera–electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera–electron volt gamma rays from this source.

Search for Unstable Sterile Neutrinos with the IceCube Neutrino Observatory

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{μ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9}  eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

Strong Constraints on Neutrino Nonstandard Interactions from TeV-Scale ν_{μ} Disappearance at IceCube

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{μτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{μτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.

Search for Relativistic Magnetic Monopoles with Eight Years of IceCube Data

We present an all-sky 90% confidence level upper limit on the cosmic flux of relativistic magnetic monopoles using 2886 days of IceCube data. The analysis was optimized for monopole speeds between 0.750c and 0.995c, without any explicit restriction on the monopole mass. We constrain the flux of relativistic cosmic magnetic monopoles to a level below 2.0×10^{-19}  cm^{-2} s^{-1} sr^{-1} over the majority of the targeted speed range. This result constitutes the most strict upper limit to date for magnetic monopoles with β≳0.8 and up to β∼0.995 and fills the gap between existing limits on the cosmic flux of nonrelativistic and ultrarelativistic magnetic monopoles.

Interferon Regulatory Factor 6 Is Necessary for Salivary Glands and Pancreas Development

Interferon regulatory factor 6 ( IRF6) acts as a tumor suppressor and controls cell differentiation in ectodermal and craniofacial tissues by regulating expression of target genes. Haploinsufficiency of IRF6 causes Van der Woude and popliteal pterygium syndrome, 2 syndromic forms of cleft lip and palate. Around 85% of patients with Van der Woude express pits on the lower lip that continuously or intermittently drain saliva, and patients with the common cleft lip and palate have a higher prevalence of dental caries and gingivitis. This study aims to identify the role of IRF6 in development of exocrine glands, specifically the major salivary glands. Our transgenic mouse model that expresses LacZ reporter under the control of the human IRF6 enhancer element showed high expression of IRF6 in major and minor salivary glands and ducts. Immunostaining data also confirmed the endogenous expression of IRF6 in the developing ductal, serous, and mucous acinar cells of salivary glands. As such, we hypothesized that Irf6 is important for proper development of salivary glands and potentially other exocrine glands. Loss of Irf6 in mice causes an increase in the proliferation level of salivary cells, disorganized branching morphogenesis, and a lack of differentiated mucous acinar cells in submandibular and sublingual glands. Expression and localization of the acinar differentiation marker MIST1 were altered in Irf6-null salivary gland and pancreas. The RNA-Seq analysis demonstrated that 168 genes are differentially expressed and confer functions associated with transmembrane transporter activity, spliceosome, and transcriptional regulation. Furthermore, expression of genes involved in the EGF pathway-that is, Ereg, Ltbp4, Matn1, Matn3, and Tpo-was decreased at embryonic day 14.5, while levels of apoptotic proteins were elevated at postnatal day 0. In conclusion, our data report a novel role of Irf6 in exocrine gland development and support a rationale for performing exocrine functional tests for patients with IRF6-damaging mutations.

Acquisition of a gastric or duodenal phenotype on heterotropic transplantation of esophagus and bladder tissues in F344 rats

Cell differentiation is very important but not well understood. In the present study the ability of various tissues to newly-differentiate when transplanted into the fundus or the duodenum in rats was tested. Pieces of esophagus, bladder, diaphragm and trachea from 8-week-old male F344 rats were transplanted into the gastric fundus or duodenum of females and examined after 3 or 6 months. While the diaphragm was not recognizable as a muscle layer in either the stomach or the duodenum, the esophagus and trachea persisted, the latter with the presence of cartilage. Esophagus grafts transplanted into the glandular stomach and duodenum, newly-differentiated into gastric and duodenal mucosa, respectively. Goblet cells with alcian-blue positive mucin appeared in bladder tissue implanted into the duodenum. Six months after the operation, their numbers had increased and cytoplasm alkaline phosphatase (ALP) positivity was noted. Gastrointestinal and also bladder stem cells may thus have multipotential ability for differentiation and may be able to newly-differentiate when transplanted into different environments in the gastrointestinal tract.

Effects of age and menopause on spinal bone mineral density in Japanese women: a ten-year prospective study

In order to determine the age and menopause-related changes in spinal bone mineral density (BMD) in healthy Japanese women, the spinal BMD at L(2-4) was measured by dual X-ray absorptiometry (DXA) in 172 healthy Japanese women aged 31-69 years (mean age 53.1+/-6.7 years) in 1990 and 2000. This prospective study showed that there was no significant decrease of BMD in premenopausal women, but there was a significant decrease of BMD (-1.59%/year) in the early post menopausal women when compared with the premenopausal and late postmenopausal women (P <0.0001). The rate of decrease in BMD slowed down with the prolongation of the years since menopause (YSM). In postmenopausal women the annual rate of decrease in BMD for obese women was significantly lower than that for slim ones (P <0.01), suggesting that fat tissue may be effective for preventing bone loss. A multiple regression analysis of variables contributing to the annual rate of decrease in spinal BMD showed that YSM and physiological age were the most influential factors, considering other factors such as weight, height and bone mass index. In conclusion, an accelerated bone loss was seen in the early postmenopausal stage. The YSM and physiological age were the most important factors that affect the rate of bone loss in healthy postmenopausal Japanese women.

Relationship between formation of a filtering bleb and an intrascleral aqueous drainage route after trabeculectomy: evaluation using ultrasound biomicroscopy

We evaluated the relationship between the development of filtering bleb and the thickness of the aqueous drainage route beneath the scleral flap in patients who had undergone trabeculectomy. The relationship between the postoperative intraocular pressure and the size of the filtering bleb was also studied. We studied 29 eyes of 21 patients who had been followed for at least 1 (mean 9.9) month after the trabeculectomy. Ultrasound biomicroscopy was used to examine the filtering bleb and aqueous drainage route beneath the scleral flap. The thickness of the aqueous drainage route beneath the center of the scleral flap was found to be correlated with the development of a filtering bleb (r = 0.391, p < 0.05). The size of the bleb was correlated with the intraocular pressure (r = -0.560, p < 0.05) which had not been treated with antiglaucoma medication during follow-up. Thus, preservation of the aqueous drainage route beneath the scleral flap probably influenced the development of a filtering bleb following trabeculectomy.

[Factors influencing platelet function in elderly patients with chronic phase thrombotic diseases]

To clarify the factors influencing platelet function in elderly patients with chronic thrombotic disease, platelet aggregability was studied in 839 blood samples from 497 patients with a variety of diseases. Clinical stage (thrombotic disease), vascular risk factors, and data concerning any administration of antiplatelet drugs were assessed, as well as brain computerized tomographic and carotid ultrasonographic findings. Platelet aggregability was determined spectrophotometrically with an aggregometer (PAM-8T) and adenosine-5'-diphosphate as an agonist to determine new parameters: the grading curve (GC) type, and platelet aggregability threshold index (PATI). Multiple regression analysis showed that the antiplatelet therapy greatly influenced the GC type. Platelet aggregability, which accelerated with aging, was strongly suppressed by ticlopidine. Furthermore, excluding samples with antiplatelet therapy, statistical analysis showed that platelet aggregability was accelerated in women, and in patients with bilateral or complicated carotid lesions, although these patients were significantly older than the others. These findings suggested that accelerated aggregability in the elderly substantially reflected the progress of arteriosclerosis with age. Moreover, the findings indicated that the determination of GC type and PATI were useful in monitoring elderly patients receiving antiplatelet therapy, especially with ticlopidine.

[Ultrasonographic findings of carotid arteries in female patients with arteriosclerosis obliterans and aortic aneurysm]

To clarify carotid arterial changes in female patients with arteriosclerosis obliterans (ASO) and aortic aneurysm (AA), ultrasonographic (US) findings of the extra-cranial carotid arteries were studied in 26 patients with ASO (ASO group), and 31 patients with AA (AA group), compared to 38 controls (control group) with neither ASO nor AA. ASO was diagnosed with an ankle pressure index less than 0.9, while AA was done with computed tomography or angiography. Half of the patients with ASO were in stage II of the Fontaine clinical staging, and angiography, performed in 12, showed femoral arterial obstruction in 10. Most AA patients were abdominal aortic aneurysm. Using a high-resolution, real-time, B-mode US instrument, the diameter and wall thickness of the common carotids were measured bilaterally in the end-diastolic phase, and occlusive changes and plaque were estimated. As a risk factor for arteriosclerosis, hypertension, diabetes, hyperlipidemia, and cigarette smoking were assessed, in addition to the age, body height and weight. Mean ages of each group were 73 to 76.3 year-old. There was no significant difference between them in body height and weight. Diabetes, cigarette smoking, and cerebrovascular disease were frequent in the ASO group, whereas ischemic heart disease was frequent in the AA group. US findings revealed that carotid lesions were mostly plaque, and bilateral carotid lesions were significantly more frequent in the ASO and AA groups. The mean wall thickness of the carotids was greater in the AA and ASO groups, although dilated carotid arteries, namely arteriomegaly, was more frequent in the AA group than in the ASO and control groups. Stepwise regression analyses demonstrated that strong correlations were seen between carotid lesion and two variables [vessel diseases (ASO/AA) and cigarette smoking], between carotid diameter and three variables (age, AA, and wall thickness), and between the wall thickness and three variables (age, vessel diseases and diameter). These findings showed that atherosclerosis was not only frequent in female patients with ASO and AA, but arteriomegaly was characteristic in female patients with AA. Therefore, it suggested that circulatory disturbance in whole organs due to arteriosclerosis should be paid attention even in female patients with ASO and AA as well as male patients. Furthermore, it is considered that systemic fragility of the arterial media and ectasia could be present extensively in patients with AA.

Severe antecollis during antipsychotics treatment: a report of three cases

1. The authors report on three patients with severe antecollis that developed after chronic treatment with antipsychotics. These patients had been treated with neuroleptics for their delusions and hallucinations. Antecollis is a rare form of tardive dystonia that has drawn little attention. To our knowledge, there have been no reports on this disorder. 2. The patients developed the symptom after receiving a number of antipsychotics for 4 months to 14 years. Neither discontinuation of antipsychotics nor administration of anticholinergic agents affected the symptom. 3. Although spontaneous improvement of dystonia was obtained after several months without any specific treatment in one patient, the symptom persisted for several years in another. The last patient could not be followed after discharge from our hospital since she and her family did not come to the hospital. 4. Severe antecollis may cause disturbances in various functions, such as vision, speaking and swallowing. Forward bending of the neck may cause inspiratory obstruction. Severe antecollis may not be unusual and psychiatrists should be aware of this symptom in routine clinical practice.

Subretinal administration of tissue-type plasminogen activator to speed the drainage of subretinal hemorrhage

BACKGROUND

Bleeding into the subretinal space in the vicinity of the macula is associated with age-related macular degeneration or retinal arterial macroaneurysm. The prognosis for restoration of vision is poor in the presence of blood clots.

METHODS

Using a simple device composed of three disposable syringes we injected tissue-type plasminogen activator (tPA) into the subretinal space during conventional vitrectomy in six patients to assist the draining of subretinal clots.

RESULTS

Four of six patients recovered their visual acuity postoperatively, while visual acuity in the other patients was stabilized.

CONCLUSION

Early drainage of subretinal hemorrhage assisted by the introduction of tPA into the subretinal space led to uncomplicated surgery and favorable postoperative results.

Posterior capsule rupture by blunt ocular trauma

A patient with posterior lens capsule rupture caused by blunt trauma and in whom the anterior capsule and the remainder of the eyeball structure was intact had phacoemulsification and aspiration of the crystalline lens with implantation of a posterior chamber intraocular lens. Further rupture of the capsule was prevented by the fibrosis, which tightened the margin of the ruptured capsule. This case shows that blunt trauma can rupture the posterior lens capsule, leaving the anterior capsule intact.

[Hemorrhagic vascular lesions in facial injuries treated by intravascular embolization: report of two cases]

We have encountered 2 cases of hemorrhagic vascular lesion in the external carotid artery system caused by facial injury. In case 1, treatment of epistaxis by nasal packing was unsuccessful. Good result was obtained by intravascular embolization in the internal maxillary artery using polyvinyl alcohol particles and gelatin sponge pieces. In case 2, massive subgaleal hemorrhage due to tearing of the middle meningeal artery caused by a skull base fracture appeared following surgery for open skull fracture. Hemostasis was performed successfully by intravascular embolization in the middle meningeal artery using microcoils and gelatin sponge pieces. In cases of facial injuries with hemorrhagic lesions in the external carotid artery system, hemostasis is generally difficult. Referring to these two cases, we think that the treatment of choice is angiography followed by intravascular embolization.

Bone density and body composition on the Pacific rim: a comparison between Japan-born and U.S.-born Japanese-American women

Bone mineral density (BMD) of total body, spine, and proximal femur and the percentage of body fat in 151 U.S.-born Japanese-American women and 137 Japan-born immigrant Japanese-American women living in San Diego, California were measured using dual-energy x-ray absorptiometry. These data were compared with unpublished data from Japanese women obtained in previous studies in Hamamatsu, Japan. The age-adjusted BMD for the spinal level, femoral neck, Ward's triangle, trochanter, and total body, respectively, of U.S.-born Japanese-American women were 10.2, 9.8, 9.9, 9.2, and 2.7% higher than those of native Japanese women. The U.S.-born Japanese-American women had significantly higher body fat than immigrant Japanese-American women. Furthermore, the immigrant women had higher BMD and higher body fat than their native Japanese counterparts; however, no significant total-body BMD differences were found among the three groups after age, height, and weight were adjusted. The U.S.-born Japanese-American women had BMD values equivalent to those of white normals at the spine and femur. Significant life-style differences between U.S.-born and immigrant Japanese-American women were noted. Weight, exercise, early menarche, and years of lifetime estrogen exposure correlated positively with BMD. The significant negative correlates of BMD were age, smoking, and percentage of body fat. Our study presents data suggesting that immigration to the United States has produced a higher BMD in Japanese-American women that is attributable to changes in life-style and diet.

[Ocular penetration of UF-021, a new prostaglandin related compound, in the rabbit eye]

The ocular penetration and pigment affinity of topically applied UF-021, a newly developed prostaglandin-related compound, were investigated in rabbit eyes using 3H-labeled UF-021. Ten minutes to 24 hours after instillation of 0.12% of 3H-UF-021 solution into New Zealand white or pigmented rabbit eyes, the rabbits were sacrificed and the eyes were immediately enucleated. The extraocular muscles, conjunctiva, aqueous humor, cornea, iris, anterior and posterior sclera, ciliary body, lens, vitreous, retino-choroid complex, optic nerve were separated and blood samples were taken. The concentration of 3H-UF-021 in each sample was determined with a liquid scintillation counter. The peak concentration of UF-021 was obtained at 40 minutes and 1 hour after instillation in the iris-ciliary body and aqueous humor of albino rabbit. According to the pharmacokinetic analysis of the data, UF-021 showed good ocular penetration into the rabbit eye, and the permeability of the epithelial barrier for UF-021 was calculated to be 2.9 x 10(-3) cm/hr. The apparent elimination rate constant and the apparent absorption rate constant were also calculated to be 0.21 hr-1 and 1.28hr-1, respectively. The time course for 3H-UF-021 concentration in the eye of pigmented rabbit was almost the same as that in the eye of non-pigmented rabbit, indicating that UF-021 did not bind to pigmented tissues.

Bone mineral density of the spine in normal Japanese subjects using dual-energy X-ray absorptiometry: effect of obesity and menopausal status

Bone mineral density (BMD) of the lumbar spine was measured to determine normal Japanese values and to examine the effect of obesity and menopausal status on BMD. Normal Japanese subjects (N = 1,296, 1,048 women and 248 men) were examined using dual-energy X-ray absorptiometry. BMD for men peaked between age 20 and 29. For women, there was abrupt bone loss after age 50. Obese women within the same age bracket had a higher BMD than thin women after age 40-49. We determined that BMD began to decline during the irregular menstruation period before the onset of menopause. We conclude that there is a positive correlation between obesity and BMD, particularly in postmenopausal women. In addition, we found that bone loss related to menopause begins during the irregular menstruation period before menopause.

[An adult case of the left coronary artery anomalously originating from the pulmonary artery (BWG syndrome), demonstrating remarkable improvement in postoperative thallium-201 myocardial imaging]

Stress thallium-201 myocardial scintigraphy were performed in a 44-year-old female with BWG syndrome before and after aorto-coronary bypass surgery. Preoperative stress thallium-201 studies demonstrated anterior reversible perfusion defect and posterior persistent defect. But postoperative studies demonstrated no defects in both areas. These data suggest that preoperative anterior defect was due to transient myocardial ischemia, but the finding of posterior persistent defect wasn't due to infarction or scarring. Thus, stress thallium-201 myocardial imaging provided useful informations to clarify the myocardial perfusion patterns pre- and postoperatively.

Human alpha 1-microglobulin levels in various body fluids

alpha 1-Microglobulin levels in serum and urine were estimated by using single radial immunodiffusion, resulting in the following mean values: umbilical cord blood serum, 40.6 mg/l; normal adult serum, 44.2 mg/l; and normal urine, 5.7 mg/24 h urine volume. Slightly higher levels of serum alpha 1-microglobulin were found in infants and the aged. Serum and urine alpha 1-microglobulin levels in patients with renal failure, however, were greatly increased, mean levels being 231.5 mg/l and 100.7 mg/24 h urine volume, respectively. Serum alpha 1-microglobulin levels in these patients correlated well with both serum creatinine and beta 2-microglobulin levels. Serum alpha 1-microglobulin level did not correlate positively with serum levels of other plasma proteins, such as alpha 1-antitrypsin, haptoglobin, complement, etc. Ouchterlony immunodiffusion also revealed the presence of alpha 1-microglobulin in synovial fluid, ascites, pleural effusion, amniotic fluid, cyst fluid, and cerebrospinal fluid. The levels of alpha 1-microglobulin in these fluids were measured by single radial immunodiffusion, except that its level in cerebrospinal fluid was measured by radioimmunoassay. Mean alpha 1-microglobulin concentration was 20.8 mg/l in synovial fluid, 28.7 mg/l in ascites, 21.5 mg/l in pleural effusion, 2.7 mg/l in amniotic fluid, 8.2 mg/l in cyst fluid, and 42.3 ng/ml in cerebrospinal fluid.

Synthesis and secretion of alpha 1-microglobulin by human lymphocytes

alpha 1-Microglobulin (alpha 1-m) was purified by column chromatography from a supernatant fluid of cultured T and B lymphocytes stimulated with mitogens. This protein had a molecular weight of 33,000 as determined by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis, migrated in the alpha 1-region on immunoelectrophoresis and proved immunologically identical to alpha 1-m which had been purified from the urine of patients with renal tubular disorders. Using indirect immunofluorescence, alpha 1-m was detected on the surface of both T and B lymphocytes, displaying the same intensity on each cell type. These findings indicate that alpha 1-m is actively produced and secreted by T and B lymphocytes.

Cellular cooperation in lymphocyte activation. II. Cooperative response of human peripheral T and B lymphocytes to rabbit anti-human beta 2-microglobulin

In the present study we attempted to clarify the effects of anti-beta 2-microglobulin (a-beta 2m) on lymphocyte activation. Neither a-beta 2m IgG fraction nor F(ab')2 had a mitogenic effect on either highly purified T or B lymphocytes alone, while their mitogenic effect was observed when T and B lymphocytes were appropriately reconstituted. When T lymphocytes were reconstituted with mitomycin C (MMC) treated B lymphocytes, a negligible decrease in the response to a-beta 2m was observed compared to the response of an untreated mixture to a-beta 2m. On the other hand, when B lymphocytes were reconstituted with MMC-treated T lymphocytes, the response was markedly diminished. It was found, moreover, that the response of T lymphocytes separated by a semipermeable membrane from MMC-treated B lymphocytes was not enhanced, while a mixture of T and MMC-treated B lymphocytes in the same chamber showed a marked response. These results lead to the conclusion that the cells responding to a-beta 2m are mainly T lymphocytes whose response is strongly enhanced by B lymphocytes, and that for the mitogenic effect of a-beta 2m direct cell-to-cell interaction between T and B lymphocytes is necessary.

Human IgA1 half-molecules: clinical and immunologic features in a patient with multiple myeloma

Abnormal IgA1 half-molecules consisting of one heavy and one light chain were found in a patient (N.N.) with typical multiple myeloma. The serum and the urine of this patient contained both 7.0S and 3.9S IgA myeloma proteins. The IgA half-molecules (3.9S) were found to have a molecular weight of 59,000 daltons and were composed of one alpha1 chain of about 40,000 daltons and one light chain of 22,000 daltons. Furthermore, enzymatic degradation suggested that the alpha chain of the N.N. half-molecules had a large deletion in its Fc portion. We suggest that its heavy and light chains were probably bound noncovalently, since the interchains connecting the heavy and light chains of these IgA half-molecules were easily dissociated with 1% SDS and 8 M urea. Cytologic studies identified at least two types of myeloma cells, and it is possible that half-molecule IgA production might result from mutation among the myeloma cells producing whole-molecule IgA.

Tissue distribution of human alpha1-microglobulin

Human alpha(1)-microglobulin was isolated from the urine of patients with tubular proteinuria, and its molecular weight was established by sodium dodecyl sulfate-polyacrylamide gel electrophoresis at 33,000 daltons. The carbohydrate content was 21.7%. Anti-alpha(1)-microglobulin serum was prepared and observed to react monospecifically in gel diffusion to purified alpha(1)-microglobulin, as well as to normal human serum and urine. Sera from the domestic chicken, mouse, rat, rabbit, dog, calf, cow, goat, sheep, and horse, however, did not react to anti-alpha(1)-microglobulin serum in immunodiffusion. The lymphocyte culture supernate was found to contain alpha(1)-microglobulin. Both thymus-derived(T)- and bone marrow-derived(B)-lymphocyte culture media clearly displayed a specific precipitin line against anti-alpha(1)-microglobulin serum when tested with the Ouchterlony immunodiffusion method. The tissue distribution of alpha(1)-microglobulin was studied under immunofluorescence, and a positive staining was recognized on the lymphocyte surface. Identical staining patterns were noted on both T and B lymphocytes, though B lymphocytes took a more intense stain. It would thus seem quite possible that lymphocytes are the primary source of alpha(1)-microglobulin and that this is filtered through the glomerular basement membrane and partly reabsorbed by the renal tubules. This, then, would suggest the possibility that alpha(1)-microglobulin shares some immunological role in vivo with lymphocytes and(or) is one of the membrane proteins of lymphocytes.

beta2-Microglobulin production by highly purified human T and B lymphocytes in cell culture stimulated with various mitogens

This study attempts to evaluate beta2-microglobulin production by highly purified (greater than 98%) peripheral and tonsil T and B lymphocytes cultured with various mitogens. beta2-Microglobulin was measured by the radioimmunoassay method. It was found that PHA and Con A markedly stimulated beta2-microglobulin production in cultures of T but not B lymphocytes. B lymphocytes were greatly activated, on the other hand, by Staphylococcus aureau Cowan I organisms cSpA), though the level of beta2-microglobulin production was less than that observed in PHA- and Con A-stimulated T lymphocytes. PWM only slightly increased beta2-microglobulin production of T lymphocytes, although the incorporation of [3H]-thymidine was highly enhanced. The highest level of beta2-microglobulin obtained with PHA or Con A was observed when the T/B lymphocyte ratio was between 90/10 and 80/20. These results lead to the conclusion that: (1) SpA is a specific mitogen for B lymphocytes, and its mitogenicity is independent of the presence of T lymphocytes, while PHA, Con A, and PWM are ineffective as stimulants of B lymphocytes; (2) the beta2-microglobulin producing ability of B lymphocytes is less than that of T lymphocytes, even when the lymphocytes are markedly activated; (3) the beta2-microglobulin production and DNA synthesis by T lymphocytes is markedly enhanced by the helper effect of B lymphocytes; (4) the level of beta2-microglobulin production reflects lymphocyte activation, especially in T lymphocytes stimulated with PHA or Con A.

Beta2-microglobulin levels of serum and ascites in malignant diseases

Serum beta2-microglobulin levels were measured by radioimmunoassay in patients with various malignant neoplasms, ascitic patients, and also patients with definite or suspected hepatoma showing variable levels of serum alpha-fetoprotein. Elevated serum beta2-microglobulin levels greater than 2.5 mg/liter were found in various malignant neoplasms, especially in multiple myeloma (66.6%) and hepatoma (60.4%) The ascites/serum ratio of beta2-microglobulin levels in the patients with malignant ascites is significantly higher than in those with non-malignant ascites. However, ascites/serum ratios of total protein, IgG, albumin, creatinine levels were not significantly different between the two groups. Levels of serum beta2-microglobulin were correlated well with those of alpha-fetoprotein in the patients with definite or suspected hepatoma (r=0.72, P less than 0.001). From these results it was concluded that (1) high levels of serum beta2-microglobulin in these patients could be attributed to its hyperproduction by tumor cells or by the cells which had been infiltrated and activated, (2) it is useful to estimate the ascites/serum ratio of beta2-microglobulin levels in differentiating malignant from non-malignant ascites, and (3) it might suggest that a function of beta2-microglobulin is in some way related to that of alpha-fetoprotein, and the alpha-fetoprotein-synthesizing cells secrete a great deal of beta2-microglobulin, although its function remains unclear.