Pembrolizumab Monotherapy Versus Pembrolizumab Plus Chemotherapy in Patients With Head and Neck Squamous Cell Carcinoma

BACKGROUND/AIM

Pembrolizumab monotherapy and pembrolizumab with chemotherapy (combination therapy) are standard treatments for recurrent and metastatic head and neck squamous cell carcinoma (R/M-HNSCC). This study aimed to explore which of the two, pembrolizumab monotherapy or combination therapy is superior for long-term use.

PATIENTS AND METHODS

Participants of the study were 139 patients with histologically confirmed squamous cell carcinoma who had been treated with pembrolizumab monotherapy or combination therapy at the Kyushu University and related facilities. We analysed differences regarding long-term survival rate and adverse events (AEs) between the pembrolizumab monotherapy and combination therapy groups.

RESULTS

The overall 2-year progression-free survival and 2-year overall survival were 28.6% and 41.8%, respectively; these results were not significantly different between the two groups. Patients in the monotherapy group with AEs had a significantly better prognosis than those without AEs (in both the monotherapy and combination therapy groups). In the combination therapy group, there was no difference in prognosis between those with AEs and those without AEs (p=0.636).

CONCLUSION

Considering the treatment of R/M-HNSCC from a long-term perspective, we identified that it is better to use pembrolizumab as monotherapy than to use it in combination with chemotherapy. Combination therapy did not improve prognosis; moreover, it can also cause additional adverse effects.

Immune Checkpoint Inhibitors for Nasopharyngeal Carcinoma in a Real-world Setting in Japan

BACKGROUND/AIM

The advent of immune checkpoint inhibitor (ICI) treatment has transformed the treatment of recurrent or metastatic head and neck cancer; however, nasopharyngeal carcinoma (NPC) has not been included in major phase III trials. The clinical outcomes of ICI for NPC in real-world practice remain to be fully elucidated.

PATIENTS AND METHODS

We retrospectively reviewed 23 patients with recurrent or metastatic NPC treated with nivolumab or pembrolizumab at 6 institutions from April 2017 to July 2021 and investigated the correlation of clinicopathological factors and immune-related adverse events with the effects of ICI therapy and the prognosis.

RESULTS

The objective response rate was 39.1% and the disease control rate was 78.3%. The median progression-free survival was 16.8 months and overall survival has not been reached. As with other treatment procedures, the efficacy and the prognosis tended to be better in EBER-positive cases than in EBER-negative cases. The rate of significant immune-related adverse events that necessitated discontinuation of treatment was only 4.3%.

CONCLUSION

ICI monotherapy (e.g., nivolumab and pembrolizumab) was effective and tolerable for NPC in a real-world setting.

Social anxiety disorder in adolescents who stutter: A risk for school refusal

BACKGROUND

Stuttering is a childhood-onset fluency disorder. Part of the counseling for middle and high school students with persistent stuttering is related to school refusal. Anxiety disorders are known to contribute to school refusal. However, it is not known whether social anxiety disorder (SAD) is a factor in school refusal among adolescents who stutter.

METHODS

In our first study, we examined the relationship between school refusal and SAD in 84 middle and high school students who stutter; 26% of the 84 students were in the school refusal group and the remaining 74% were in the school attendance group. The second study examined whether SAD was associated with 10 factors related to speech and stuttering frequency using the Japanese version of the Liebowitz Social Anxiety Scale for Children and Adolescents to determine the presence of SAD. Of the 84 students in the first study, 40 participated in the second study.

RESULTS

The school refusal group of adolescents who stutter had significantly higher rates of SAD than the school attendance group. Fifty percent of adolescents who stutter met the criteria for SAD. Moreover, adolescents who stutter with SAD had significantly higher scores on the items "When speaking in public, do you experience tremors in your limbs?" and "After you stutter, do you have negative thoughts about yourself?" than the adolescents who stutter without SAD.

CONCLUSIONS

When examining adolescents who stutter, checking for comorbid SAD may lead to better support. Moreover, noticing their repetitive negative thinking, nervousness, and trembling during speech may help to resolve SAD.

Real-world Experience With Pembrolizumab for Advanced-stage Head and Neck Cancer Patients: A Retrospective, Multicenter Study

BACKGROUND/AIM

This study investigated the effectiveness of pembrolizumab with or without chemotherapy on advanced-stage head and neck cancer (HNC), including nasopharyngeal, sinonasal cavity and external auditory canal cancer, in a real-world setting.

PATIENTS AND METHODS

We retrospectively collected data from 97 HNC patients who were treated with pembrolizumab alone (n=60) or with chemotherapy (n=37), and we investigated the association between clinicopathological findings and treatment response or prognosis.

RESULTS

Patients treated with pembrolizumab and chemotherapy had a 1-year overall survival (OS) of 72.8%, objective response rate (ORR) of 48.6%, and serious (≥G3) adverse events (AEs) of 29.7%. Patients treated with pembrolizumab alone had a 1-year OS of 51.9%, ORR of 21.7%, and ≥G3 AEs of 6.7%. Both the ORR and disease control rate (DCR) in the pembrolizumab with chemotherapy group were significantly better than those in the pembrolizumab group (p=0.074 and p=0.00101, respectively). Among patients with distant metastasis, patients on pembrolizumab with chemotherapy achieved significantly better OS than pembrolizumab alone (p=0.0039). Among patients in the pembrolizumab group, both AE-positive and better performance status were associated with longer OS (p=0.011 and p=0.0037, respectively).

CONCLUSION

Our real-world experience reinforces the durability and effectiveness of pembrolizumab for HNC patients. Additionally, our results suggest that pembrolizumab with chemotherapy might be recommended for patients with distant metastasis and no prior treatment. Further studies are needed to determine the optimal treatment strategy for HNC.

Retrospective Study of Cisplatin/Carboplatin, 5-Fluorouracil Plus Cetuximab (EXTREME) for Advanced-stage Salivary Gland Cancer

BACKGROUND/AIM

Surgery remains the standard treatment for salivary gland carcinoma (SGC). Our study investigated the association between epidermal growth factor receptor (EGFR) status in recurrent/metastatic SGC and the effectiveness of treatment with cisplatin/carboplatin and 5-fluorouracil plus cetuximab (EXTREME).

PATIENTS AND METHODS

We retrospectively collected 19 SGCs from patients treated with the EXTREME regimen. After analyzing EGFR expression and gene copy number gain, we evaluated the correlation between EGFR status and clinicopathological factors and prognosis.

RESULTS

EGFR overexpression was detected in 77.8% cases, but not statistically associated with clinicopathological factors or prognosis. EGFR gene copy number gain was detected in 16.7% cases, and statistically positively correlated with lymph node metastasis (p=0.0291). The best overall response was partial response in two cases, stable disease in 15, and progressive disease in one case. The EXTREME regimen was discontinued in all cases.

CONCLUSION

Our results suggest that SGCs are positive for EGFR protein expression but the response rate to the EXTREME regimen was unremarkable.

The downregulation of NADPH oxidase Nox4 during hypoxia in hemangioendothelioma cells: a possible role of p22phox on Nox4 protein stability

NADPH oxidase (Nox) 4 produces H₂O₂ by forming a heterodimer with p22^phox and is involved in hemangioendothelioma development through monocyte chemoattractant protein-1 (MCP-1) upregulation. Here, we show that Nox4 protein levels were maintained by p22^phox in hemangioendothelioma cells and Nox4 protein stability was dependent on p22^phox coexpression. Conversely, the degradation of Nox4 monomer was enhanced by p22^phox knockdown. Under hypoxic conditions in hemangioendothelioma cells, p22^phox was downregulated at the mRNA and protein levels. Downregulation of p22^phox protein resulted in the enhanced degradation of Nox4 protein in hypoxia-treated hemangioendothelioma cells. In contrast, Nox2, a Nox isoform, was not altered at the protein level under hypoxic conditions. Nox2 exhibited a higher affinity for p22^phox compared with Nox4, suggesting that when coexpressed with Nox4 in the same cells, Nox2 acts as a competitor. Nox2 knockdown restored Nox4 protein levels partially reduced by hypoxic treatment. Thus, Nox4 protein levels were attenuated in hypoxia-treated cells resulting from p22^phox depletion. MCP-1 secretion was decreased concurrently with hypoxia-induced Nox4 downregulation compared with that under normoxia.

Awareness of stuttering in Japanese children aged 3-7 years

BACKGROUND

Boey et al. (2009) devised a questionnaire for measuring children's awareness of stuttering and showed that even very young children were often aware of their stuttering. There has been no replication of studies using Boey et al.'s parent-reported questionnaire. The aim of this study was to test whether using Boey et al.'s seven questions, developed for a Dutch speaking population could be effective for measuring the awareness of stuttering in Japanese children.

METHODS

Participants were 54 children who stutter (CWS) aged 3-7 years. Parents answered seven questions about their child's awareness of stuttering according to the questions developed Boey et al. RESULTS: Parental-reported observations of the child responses citing at least one awareness incident were 76%. The percentage of stuttering children with awareness of their own speech difficulties, according to chronological age, were as follows: 70% at age 3 years; 67% at age 4 years; 75% at age 5 years; 81% at age 6 years; and 90% at age 7 years.

CONCLUSIONS

We found that even at age 3 years, many CWS were already aware of their stuttering. The similarity of the data with the seminal study by Boey et al. suggests that the question-based assessment is reproducible even in a country with a different spoken language. The seven questions in Boey et al. are useful for evaluating whether children's awareness of stuttering could contribute to a clinical decision as well as stuttering severity.

Constitutive activity of NADPH oxidase 1 (Nox1) that promotes its own activity suppresses the colon epithelial cell migration

Superoxide producing NADPH oxidase 1 (Nox1), abundantly expressed in the colon epithelium, plays a crucial role in mucosal host defenses. In this study, we found that pre-treatment of cells with edaravone, a free radical scavenger, inhibited Nox1 constitutive activity even after washout without affecting Nox1 trafficking to the plasma membrane and membrane recruitment of the cytosolic regulators Noxo1 and Noxa1. These results suggest that a Nox1-derived product is involved in the step that initiates the electron transfer reaction after the formation of the Nox1-Noxo1-Noxa1 complex. Furthermore, we show that the mean migration directionality and velocity of epithelial cells were significantly enhanced by the inhibition of constitutive Nox1 activity. Thus, the constitutive Nox1 activity limits undesired cell migration in resting cells while participating in a positive feedback loop toward its own oxidase activity.

The NADPH oxidase NOX4 promotes the directed migration of endothelial cells by stabilizing vascular endothelial growth factor receptor 2 protein

Directed migration of endothelial cells (ECs) is an important process during both physiological and pathological angiogenesis. The binding of vascular endothelial growth factor (VEGF) to VEGF receptor-2 (VEGFR-2) on the EC surface is necessary for directed migration of these cells. Here, we used TAXIScan, an optically accessible real-time horizontal cell dynamics assay approach, and demonstrate that reactive oxygen species (ROS)-producing NADPH oxidase 4 (NOX4), which is abundantly expressed in ECs, mediates VEGF/VEGFR-2-dependent directed migration. We noted that a continuous supply of endoplasmic reticulum (ER)-retained VEGFR-2 to the plasma membrane is required to maintain VEGFR-2 at the cell surface. siRNA-mediated NOX4 silencing decreased the ER-retained form of VEGFR-2, resulting in decreased cell surface expression levels of the receptor. We also found that ER-localized NOX4 interacts with ER-retained VEGFR-2 and thereby stabilizes this ER-retained form at the protein level in the ER. We conclude that NOX4 contributes to the directed migration of ECs by maintaining VEGFR-2 levels at their surface.

A clinical analysis of sinonasal squamous cell carcinoma: a comparison of de novo squamous cell carcinoma and squamous cell carcinoma arising from inverted papilloma

Background: Sinonasal squamous cell carcinoma (SCC) is a rare tumor arising either de novo or in association with inverted papillomas (IPs).Objectives: The aim of this study was to investigate and compare the oncological features and prognosis of patients with sinonasal SCCs based on their etiology.Material and methods: The medical records of 117 patients who had been diagnosed with de novo SCC or those arising from IP (IP-SCC) were retrospectively reviewed. In situ hybridization analyses to detect HPV 16/18DNA and p16 immunohistochemistry were also performed in 10 cases with IP-SCC.Results: The three-year disease-specific survival (DSS) rate was higher in cases with T1, 2 and 3 than in cases with T4 in both tumor groups. T4 cases with de novo SCC had a better DSS than those with IP-SCCs. HPV16/18 was not detected in any of the 10 IP-SCCs.Conclusions and significance: T4 cases with de novo SCC tended to have a better DSS than those with IP-SCC. Since some T4 patients with IP-SCC were found to have a highly aggressive disease, careful treatment planning should be performed. High-risk HPV may not play a vital role in the carcinomatous transformation of most IP-SCC cases.

Relationship between immune-related adverse events and the long-term outcomes in recurrent/metastatic head and neck squamous cell carcinoma treated with nivolumab

OBJECTIVES

Immune-related adverse events (irAEs) have been shown to be associated with higher antitumor responses and a clinical benefit in non-small cell lung carcinoma, renal cell carcinoma, and melanoma patients. However, little is known regarding the association between irAEs and the clinical effect of nivolumab for recurrent/metastatic head and neck squamous cell carcinoma (R/MHNSCC).

MATERIALS AND METHODS

We evaluated 108 patients treated with nivolumab for R/MHNSCC at 2 participating institutions. IrAEs were identified and profiled. We analyzed the association of each immune-related adverse effect with the clinical outcome of the patients.

RESULTS

Among 108 patients, the objective response rate (ORR) was 29.6% (32/108 patients), and the disease control rate (DCR) was 50.0% (54/108 patients). IrAEs were observed in 41 patients (38.0%). Patients with irAEs had a significantly higher ORR and DCR than those without irAEs (46.3% vs. 19.4%, P = 0.004 and 75.6% vs. 34.3%, P < 0.001, respectively). The median progression-free and overall survival rates in patients with irAEs were significantly longer than in those without irAEs.

CONCLUSIONS

There was a significant relationship between irAEs and efficacy in R/MHNSCC patients treated with nivolumab. Our results indicate that the development of irAEs may aid in the earlier prediction of anticancer effects in patients with recurrent or metastatic HNSCC during nivolumab monotherapy.

Small Cell Carcinoma in the Head and Neck

OBJECTIVES

Small cell carcinomas in extrapulmonary sites (ESmCCs) are very rare. ESmCCs originating in the head and neck account for approximately 10% of all ESmCCs, and there are few reports about this disease. ESmCCs have an aggressive natural history characterized by widespread metastasis. The aim of this study was to investigate the characteristics and outcomes of patients with ESmCCs of the head and neck.

METHODS

The outcomes of 21 patients with ESmCCs of the head and neck treated between January 2001 and December 2015 at the authors' hospital and associated facilities were reviewed.

RESULTS

There were 18 men and 3 women, and the median age was 74 years (range, 53-91 years). The tumor site was the larynx in 6 patients; the paranasal sinus in 5; the hypopharynx in 3; the oropharynx in 2; the nasopharynx in 2; and the oral cavity, salivary gland, and primary unknown in 1 patient each. The extent of the disease was staged as follows: stage I or II, 3 cases; stage III, 4 cases; stage IVA, 9 cases; stage IVB, 1 case; and stage IVC, 4 cases. The median observation time was 17 months (range, 1-103 months). Four patients (19%) had distant metastasis at initial treatment, and 13 patients (62%) developed distant metastasis within 3 years. Treatments were administered, including radical surgery (9 patients), radiation therapy (5 patients), chemoradiotherapy (7 patients), and chemotherapy (6 patients). The 1- and 3-year overall survival rates of patients were 56% and 37%, respectively. More than half of the patients died of distant metastasis.

CONCLUSIONS

ESmCCs of the head and neck have a poor prognosis, similar to those of carcinomas in many other sites. Control of distant metastasis would contribute to improving the prognosis of ESmCCs of the head and neck. Further studies are required for better understanding these disease entities and their response to treatment modalities.

Monitoring the neutrophil-to-lymphocyte ratio may be useful for predicting the anticancer effect of nivolumab in recurrent or metastatic head and neck cancer

BACKGROUND

Predicting the response to treatment with nivolumab and the survival in patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) remains a challenge. We investigated whether or not the neutrophil-to-lymphocyte ratio (NLR) kinetics could be used to predict the anticancer effect of nivolumab.

PATIENTS AND METHODS

Forty-one patients with recurrent or metastatic HNSCC who had been treated with nivolumab were retrospectively analyzed. The NLR was calculated using pretreatment blood test results until the end of the treatment.

RESULTS

The posttreatment NLR was higher than the pretreatment value in 13 of 17 patients (76%) patients with progressive disease within the first 3 months, whereas the posttreatment NLR was lower than the pretreatment value in 10 of 11 patients (91%) with stable disease or partial response during the follow-up period.

CONCLUSION

Our results indicate that monitoring the NLR may aid in the earlier confirmation of treatment failure in patients with recurrent or metastatic HNSCC during nivolumab monotherapy.

Salvage of recurrent hypopharyngeal carcinoma after primary curative treatment

CONCLUSIONS

There was a moderate chance of cure after surgical salvage of recurrent hypopharyngeal squamous cell carcinoma (SCC). However, surgical salvage was only feasible for early recurrent tumor. Close follow-up surveillance to detect early recurrence is essential after primary treatment of patients.

OBJECTIVES

Despite improvements in surgery, radiotherapy, and chemotherapy, hypopharyngeal SCC has one of the worst prognoses among head and neck malignant diseases. To improve the overall survival and cure rates in patients with hypopharyngeal SCC, the management of recurrent disease as well as initial treatment is important. In this study, the efficacy and results of salvage treatment of recurrent hypopharyngeal SCC after primary curative treatment were evaluated.

METHODS

The management outcomes of 49 patients who were treated for recurrent hypopharyngeal SCC between January 2002 and December 2010 at Kyushu University Hospital were reviewed.

RESULTS

The median time for detection of recurrence from the initial curative treatment was 10.3 months (range 2.1-61.1 months). The total salvage rates of recurrence were 45% (local, 85%; locoregional, 100%; regional, 23%; distant, 19%). The 1- and 3-year tumor-free actuarial survival rates of those patients who received salvage surgery followed by chemotherapy and/or radiotherapy were 96% and 79%, respectively. There was no 3-year survivor among the patients who received only chemotherapy and/or radiotherapy.

Expression and function of Noxo1gamma, an alternative splicing form of the NADPH oxidase organizer 1

Activation of the superoxide-producing NADPH oxidase Nox1 requires both the organizer protein Noxo1 and the activator protein Noxa1. Here we describe an alternative splicing form of Noxo1, Noxo1gamma, which is expressed in the testis and fetal brain. The Noxo1gamma protein contains an additional five amino acids in the N-terminal PX domain, a phosphoinositide-binding module; the domain plays an essential role in supporting superoxide production by NADPH oxidase (Nox) family oxidases including Nox1, gp91(phox)/Nox2, and Nox3, as shown in this study. The PX domain isolated from Noxo1gamma shows a lower affinity for phosphoinositides than that from the classical splicing form Noxo1beta. Consistent with this, in resting cells, Noxo1gamma is poorly localized to the membrane, and thus less effective in activating Nox1 than Noxo1beta, which is constitutively present at the membrane. On the other hand, cell stimulation with phorbol 12-myristate 13-acetate (PMA), an activator of Nox1-3, facilitates membrane translocation of Noxo1gamma; as a result, Noxo1gamma is equivalent to Noxo1beta in Nox1 activation in PMA-stimulated cells. The effect of the five-amino-acid insertion in the Noxo1 PX domain appears to depend on the type of Nox; in activation of gp91(phox)/Nox2, Noxo1gamma is less active than Noxo1beta even in the presence of PMA, whereas Noxo1gamma and Noxo1beta support the superoxide-producing activity of Nox3 to the same extent in a manner independent of cell stimulation.

Molecular mechanism underlying activation of superoxide-producing NADPH oxidases: roles for their regulatory proteins

The phagocyte NADPH oxidase is dormant in resting cells but becomes activated during phagocytosis to produce superoxide, a precursor of microbicidal oxidants, thereby playing a crucial role in host defence. The catalytic core of this enzyme comprises the two membranous subunits gp91phox/Nox2 and p22phox. The oxidase activation requires the small GTPase Rac and the SH3 domain-containing proteins p47phox and p67phox; they normally exist in the cytoplasm and translocate upon cell stimulation to the membrane. The translocation depends on a stimulus-induced conformational change of p47phox, which leads to the SH3 domain-mediated interaction with p22phox, a binding required for the gp91phox/Nox2-dependent superoxide production. Activation of Nox1, an oxidase that is likely involved in host defence at the colon, requires novel proteins homologous to p47phox and p67phox, designated Noxo1 and Noxa1, respectively. Noxo1 and Noxa1, both expressed abundantly in the colon, are capable of constitutively activating Nox1. The constitutive activation may be due to the property of Noxo1: in contrast with p47phox, Noxo1 seems to normally associate with p22phox, which is required for the Nox1 activation. We will also describe the mechanism underlying regulation of the third oxidase Nox3, which exits in fetal kidney and inner ears.

Novel human homologues of p47phox and p67phox participate in activation of superoxide-producing NADPH oxidases

The catalytic core of a superoxide-producing NADPH oxidase (Nox) in phagocytes is gp91phox/Nox2, a membrane-integrated protein that forms a heterodimer with p22phox to constitute flavocytochrome b558. The cytochrome becomes activated by interacting with the adaptor proteins p47phox and p67phox as well as the small GTPase Rac. Here we describe the cloning of human cDNAs for novel proteins homologous to p47phox and p67phox, designated p41nox and p51nox, respectively; the former is encoded by NOXO1 (Nox organizer 1), and the latter is encoded by NOXA1 (Nox activator 1). The novel homologue p41nox interacts with p22phox via the two tandem SH3 domains, as does p47phox. The protein p51nox as well as p67phox can form a complex with p47phox and with p41nox via the C-terminal SH3 domain and binds to GTP-bound Rac via the N-terminal domain containing four tetratricopeptide repeat motifs. These bindings seem to play important roles, since p47phox and p67phox activate the phagocyte oxidase via the same interactions. Indeed, p41nox and p51nox are capable of replacing the corresponding classical homologue in activation of gp91phox. Nox1, a homologue of gp91phox, also can be activated in cells, when it is coexpressed with p41nox and p51nox, with p41nox and p67phox, or with p47phox and p51nox; in the former two cases, Nox1 is partially activated without any stimulants added, suggesting that p41nox is normally in an active state. Thus, the novel homologues p41nox and p51nox likely function together or in combination with a classical one, thereby activating the two Nox family oxidases.

Release of thyroid hormone from circulating thyroglobulin in the rat

Under normal conditions, a small amount of thyroglobulin (Tg) exists in peripheral blood. However, the fate of circulating Tg is unclear. In the present study, in vivo labelled rat Tg was injected iv into rats whose thyroids had been blocked with KI to determine whether circulating Tg released thyroid hormone by hydrolysis in extrathyroidal tissues. Radiolabelled Tg was obtained from thyroid of rats injected with 125I 24h before sacrifice, and subsequently purified by ammonium sulphate precipitation. The plasma samples were obtained from tail veins or by cardiac punctures at various times following injection of [125I]rat Tg. The radioactive samples were separated into iodoprotein, iodoaminoacid and iodide fractions using columns of anion and cation exchange resins. The per cent radioactivity of the iodoprotein, iodoaminoacid an iodide fractions, respectively, was 91.2, 3.8 and 5.2 at 15 min and 66.9, 17.4 and 15.4 at 20 h after injection. In the iodoaminoacid fractions, the presence of T4, T3, MIT and DIT was defined by further fractionation using a Sephadex G-25 column. At 20 h after injection, more than 75% of the radioactivity of the iodoaminoacid fraction was found to be incorporated in T4 and T3. It is concluded that circulating Tg is hydrolyzed in extrathyroidal tissues and that thyroid hormone is released into the circulation, but the amounts of T4 and T3 released are not physiologically significant.

Kinetic study of immunoreactive human thyroglobulin

Thyroglobulin (Tg) can be detected in the circulation of normal subjects. Serum Tg is increased in patients with various thyroidal disorders including Graves' disease; however, little is known about Tg metabolism. Therefore, a kinetic study of human Tg was carried out in 13 normal men, 19-28 yr old, and 6 untreated hyperthyroid patients with Graves' disease, 3 men (22 to 25 yr old), and 3 women (21 to 63 yr old). Ten milligrams of Tg were injected as a bolus dose. Blood samples were collected before and 10 min, and 2, 4, 6, 8, 12 h and every 12 h up to 72 h after injection. Concentrations of serum Tg were measured by an RIA method developed in our laboratory. Anti-Tg antibody was not detected in any subject. Various indices of this kinetic study were calculated using single compartmental analysis. In 13 normal subjects, the mean serum concentrations of Tg were 17 +/- 12.6 (SD) ng/ml; mean half-life was 29.6 +/- 2.8 h; distribution volume was 11,210 +/- 3,076 ml/60 kg body weight; fractional decay was 2.40 +/- 0.22%/h; MCR was 268.9 +/- 87.8 ml/h X 60 kg; and release rate was 100.3 +/- 50.2 micrograms/day X 60 kg. Serum concentrations of Tg were increased in four of the six untreated hyperthyroid patients with Graves' disease. Their Tg half-lives and MCR were within the normal range. In the two patients who had normal serum concentrations of Tg, the Tg half-lives were shorter and MCR were greater than in normal subjects. The release rates of Tg were increased in all six of these patients. In summary, in hyperthyroid patients, Tg release is significantly greater than normal, whereas Tg metabolism is similar to that in normal subjects.

Degradation of circulating thyroglobulin

Reported half lives of rat Tg were different according to various investigators. In order to elucidate whether the derivatives of rat Tg in the peripheral circulation affect the results of kinetic studies of Tg, the present study was performed to investigate kinetics of rat Tg after separation of 19S Tg from its derivatives using gel-filtration. Radiolabeled Tg was obtained from thyroids of rats injected with 125I 24 hours before death, and subsequently purified by ammonium sulfate precipitation. The plasma samples obtained at varying time intervals after intravenous injection of 125I-rat Tg were fractionated on a Sephacryl S-300 column. As determined by sucrose density gradient, 99% of in vivo radiolabeled Tg was 19S. On gel-filtration, the injected labeled Tg and plasma samples obtained within two hours after injection showed a single peak in an identical area. A second peak in an area corresponding to a molecular weight of 60,000 to 70,000 appeared within six hours, and became as high as the first within 24 hours. In the second peak, 22.8 +/- 3.8% (mean +/- SE) of radioactivity was precipitated by anti-rat Tg antibody, and 14.4 +/- 1.7% (mean +/- SE) of radioactivity of its TCA precipitate was not extracted by n-butanol. Thus, the second peak could affect the results of Tg kinetic studies which utilize TCA precipitation, n-butanol extraction or RIA procedures. The half life of rat Tg in the present study was calculated from the disappearance curves of radioactivity of 19S Tg separated from other radioactive substances.(ABSTRACT TRUNCATED AT 250 WORDS)

Vitamin D-induced coronary atherosclerosis in normolipemic swine: comparison with human disease

Coronary atherosclerosis developed in normolipemic swine fed a basal ration supplemented with 125,000 IU, 62,500 IU and 31,250 IU of vitamin D3/kg of diet for 3 months and subsequently only the basal ration for the following 3 months. Lesions consisted of intimal atheromata and calcified internal elastica and caused luminal narrowing. The incidence of atherosclerotic lesions was proportional to the vitamin D3 doses. The present experimentally induced lesions had many morphological features resembling those in coronary arteries from human subjects.

Morphological alteration of aortic wall and mitotic cells after complete endothelial loss induced by repeated balloon denudation of swine aorta

The aortic endothelium in weanling swine was rubbed ten times with an inflated balloon catheter in a repeated balloon denudation. This procedure produced more drastic, extensive and uniform changes in the aortic wall than the commonly used balloon denudation. Sequential alternations of regenerating endothelium, intimal thickening and medial reaction, and the incidence of mitotic cells were studied by scanning and transmission electron microscopy. Complete endothelial loss was confirmed from the descending thoracic aorta to the right femoral artery within 24 hr. By the third day, regenerated endothelium began to cover over the endothelial defect area from the uninjured areas such as the aortic arch and the orifices of branching arteries. Thrombus formation and fibromuscular intimal thickening were observed in the endothelial defect areas by the fifth and seventh days. Three types of mitotic cells, such as endothelial, intimal and medial cells were noted in the aortic wall. Mitotic endothelial and mitotic medial cells were most frequent at Day 3; the latter were closely associated with dead medial cells. Mitotic intimal cells initially appeared at Day 3 and were most frequent at Day 7. Mitotic intimal and mitotic medial cells were frequently present in the aortic wall subjacent to the endothelial defect areas containing interstitial blood components. The large numbers of mitotic aortic cells indicated that endothelial cells give rise to new endothelial cells, intimal cells to new intimal cells, and medial cells to new medial cells.

Ultrastructure of cardiovascular lesions induced by hypervitaminosis D and its withdrawal

Aortic, coronary and cardiac lesions were induced in swine by a hypervitaminosis D3 diet Lipid-free intimal plaques overlying focally calcified medial or internal elastica occured in the thoracic aorta, pulmonary trunk and coronary artery of swine fed a basal ration supplemented with 250,000 IU of vitamin D3/kg of diet for an induction period of 4 months. Cartilage formation with minimal calcification was initiated in the aortic valve during this period. When such animals were subsequently fed only the basal ration free of excessive vitamin D3 for 3 months, intimal plaques regressed in the aorta and pulmonary trunk but progressed in the coronary artery. The calcific deposits in the medial elastica and internal elastica of all three arteries decreased in size. Atherosclerotic intimal thickening occurred in the main coronary arteries. The most severe lesion occupied 75 p.100 of the lumen area. Multiple intimal plaques were noted in the left atrium and aortic and mitral valves. The thickened intima at these coronary and cardiac sites contained calcified elastica and collagen fibers.

Mitotic structure of aortic intimal cells induced by mechanical injury in swine

Repair processes of the aortic wall have been studied electron microscopically after removal of the endothelium by an inflated balloon procedure in the thoracic aortae of swine. Initial responses after injury included a thrombotic reaction, the appearance of intimal cells over the denuded surface, and increased mitotic activity of medial cells adjacent to the dead cells by day 3. Cells which engaged in intimal thickening were classified as modified smooth muscle cells throughout the course of this investigation. Mitosis of intimal cells, which was initially observed at day 3, substantially increased at day 7 and decreased by day 14. Mitotic intimal cells contained the same cytoplasmic organelles as interphase modified smooth muscle cells. A detailed description of the paired cisternae as an ultrastructural feature of cell division of modified smooth muscle cells was provided. The paired cisternae were initially observed among the remnants of the nuclear envelope in late prophase; they remained at the periphery of the mitotic apparatus in meta- and anaphase, and finally attached themselves to the nuclear envelope of the daughter cells in late telophase.

Ultrastructure of botryoid sarcoma of the common bile duct

A case of botryoid sarcoma of the common bile duct in a 4-year-old girl was reported. Electron microscopic examination disclosed that the neoplasm consisted of three types of cells: polygonal, elongated, and small cells. The former two contained moderate to large amounts of poorly developed myofibriles in the cytoplasm with occasional A, I and Z-bands. The small cells contained mitochondria and dilated rough endoplasmic reticulum but few myofilaments. Deposits of glycogen granules were constant components of the neoplastic cells. Mitosis was striking in the small cells. Abnormal multilaminar endoplasmic reticulum was observed in the small cells in the mitotic stage.

Duplication cyst of the duodenum in the adult

A duodenal duplication cyst in a 45-year-old male is reported. A hypotonic duodenography showed a smooth spherical defect in the descending portion of the duodenum. A fiberoptic duodenoscopy disclosed a smooth well-defined tumor which was located orally from the ampulla of Vater. A retrograde pancreatocholangiography indicated the tumor was not in communication with the pancreatic duct or biliary tract. At operation, a cystic spherical mass, 3 cm in diameter, was located in the posterior wall of the duodenum corresponding to the above described diagnosis. The combination of a greater awareness of this condition as well as improved X-ray and endoscopic techniques has made preoperative diagnosis more accurate.

An ultrastructural study of the Brunner's cyst

A Brunner's cyst, removed from a 54-year-old woman, was studied by light and electron microscopy. The cyst was spherical, measured 1.5 cm in diameter and was located in the duodenal bulb. Histologically, the cyst, confined in the submucosa, consisted of a single layer of epithelial cells and connective tissue. The epithelial cells were composed of an orderly array of tall columnar cells containing basal round nuclei and fine granular cytoplasm. Ultrastructurally, the epithelial cells contained many secretory granules in the cytoplasm. Each secretory granule was membrane-bound and appeared electron-lucid with a dense core. They were small and sparse around the Golgi apparatus but large and numerous in the apical region. Multinucleated cells were intermingled with cells of the epithelial lining.