WHO informal consultation on revision of guidelines on evaluation of similar biotherapeutic products, virtual meeting, 30 June – 2 July 2021

The WHO informal consultation was held to promote the revision of WHO guidelines on evaluation of similar biotherapeutic products (SBPs) adopted by the Expert Committee on Biological Standardization (ECBS) in 2009. It was agreed in the past consultations that the evaluation principles in the guidelines are still valid, but a review was recommended to provide more clarity and case-by-case flexibility. The opportunity was therefore taken to review the experience and identify areas where the current guidance could be more permissive without compromising its basic principles, and where additional explanation could be provided regarding the possibility of reducing the amount of data needed for regulatory approval. The meeting participants applauded the leading role taken by the WHO in providing a much-needed streamlined approach for development and evaluation of SBPs which will provide efficient and cost-effective product development and increase patient access to treatments. It was recognized that the principles as currently described in the draft WHO guidelines are based on sound science and experience gained over the last fifteen years of biosimilar approvals. However, since these guidelines when finalised will constitute the global standard for biosimilar evaluation and assist national regulatory authorities in establishing revised guidance and regulatory practice in this complex area, it was felt that further revision and clarity on certain perspectives in specific areas was necessary to dispel uncertainties arising in the current revised version. This report describes the principles in the draft guidelines, including topics discussed and consensus reached.

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WHO guidelines serve as a basis for the development of national regulatory framework for biosimilars.

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Revision of guidelines is to provide more flexibility and clarification on data required for regulatory approval.

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Revised guidelines would contribute to improving consistency on regulatory decision and patient access to treatments.

Gender difference in tooth autotransplantation with complete root formation: a retrospective survey

Gender-related risk factors in the survival of transplanted teeth with complete root formation have not yet been identified. The purpose of this study was to investigate gender differences in tooth autotransplantation at dental clinics. We asked participating dentists to provide information on transplantations they had undertaken from 1 January 1990 to 1931 December 2010. The data were screened to exclude patients who underwent more than one transplantation, smokers or those whose smoking habits were unknown, patients under 30 or who were 70 years old and over, cases where the transplanted teeth had incomplete root formation or multiple roots and those with fewer than 20 present teeth post-operation. We analysed 73 teeth of 73 males (mean age, 47.2 years) and 106 teeth of 106 females (mean age, 45.3 years) in this study. The cumulative survival rate and mean survival time were calculated using the Kaplan-Meier method. The cumulative survival rate for males was 88.3% at the 5-year mark, 64.8% at 10 years and 48.6% at 15 years; for females, it was 97.2% at the 5-year mark, 85.9% at 10 years and 85.9% at 15 years. A log-rank test indicated the difference between males and females to be significant (P = 0.011). There was also a significant difference in the main causes for the loss of transplanted teeth: males lost more transplanted teeth due to attachment loss than females (P < 0.05). These results indicate that males require more attention during the autotransplantation process, particularly at the stage of pre-operation evaluation and that of follow-up maintenance.

Risk factors affecting third molar autotransplantation in males: a retrospective survey in dental clinics

The aim of this study was to investigate the risk factors affecting long-term prognosis of autotransplantation of third molars with complete root formation in males at dental clinics. Participating dentists were requested to provide information on transplantations they had undertaken from 1 January 1990 to 31 December 2010. Data on a total of 708 teeth from 637 patients were collected. After data screening and elimination, participants of this study consisted of 183 teeth of 171 males ranging from 20 to 72 years of age (mean age, 44·8 years). The cumulative survival rate was 86·0% at the 5-year mark, 59·1% at 10 years and 28·0% at 15 years. The mean survival time was 134·5 months, as calculated by the Kaplan-Meier method. Single factor analysis using the log-rank test showed that the following factors had significant influence (P < 0·05) on survival of transplanted teeth: periodontal disease as the reason for recipient site tooth extraction, fewer than 25 present teeth and Eichner index Groups B1 to C. Cox regression analysis examined five factors: age, smoking habit, recipient site extraction caused by periodontal disease, fewer than 25 present teeth and Eichner index. This analysis showed that two of these factors were significant: fewer than 25 present teeth was 2·63 (95% CI, 1·03-6·69) and recipient site extraction caused by periodontal disease was 3·80 (95% CI, 1·61-9·01). The results of this study suggest that long-term survival of transplanted teeth in males is influenced not only by oral bacterium but also by occlusal status.

Influence of serum from rats with fulminant hepatic failure on hepatocytes in a bioartificial liver system

Fulminant hepatic failure (FHF) is a life-threatening condition marked by many excessively increased unmetabolized toxins and growth factors. Recently developed bioartificial liver (BAL) systems containing hepatocytes can be used to treat patients with FHF However, the behavior of these hepatocytes on exposure to FHF serum in vitro remains unclear. In the present study, we used FHF rat models and the sera from these rats (i.e., FHF serum) contained elevated inflammatory cytokines (TNF-alpha, IL-1beta, and IL-6), HGF, and TGF-beta1. In addition, 1x10(8) hepatocytes were harvested from the livers of inbred rats and incubated with microcarrier beads. Four hours later, the hepatocyte-coated beads were inoculated into a hollow-fiber module (=BAL system). FHF serum or normal control serum circulated for 6 hours through the BAL system. Expressions of mRNA for albumin, GST A1, CYP 1A2, OTC and c-fos were investigated by RT-PCR, and PCNA staining was performed before and after perfusion. The expressions of albumin, GST A1, and CYP 1A2 mRNAs were markedly decreased, whereas those of OTC and c-fos were modestly decreased. PCNA positive cells were low and showed no difference between FHF and normal serum-exposed hepatocytes. In conclusion, the exposure of hepatocytes to hypercytokinemia, including inflammatory cytokines and positive and negative growth factors, caused a loss in liver specific functions. This environment also failed to facilitate hepatocyte regeneration.

Influence of the duration of the second stage of labor on fetal pH levels and oxidative status in uncomplicated pregnancies

OBJECTIVE

We examined the influence of the duration of the second stage of labor on fetal pH levels and oxidative status in uncomplicated pregnancies.

METHODS

Blood gases in the umbilical artery and serum uric acid and plasma malondialdehyde levels in the umbilical venous blood were measured at delivery in uncomplicated nulliparous women whose second stage of labor was 0-60 min (n = 38), 61-120 min (n = 14) and 121-180 min (n = 6).

RESULTS

There were no significant differences in the measured variables between the three groups.

CONCLUSION

The duration of the second stage of labor up to 3 h does not influence lipid peroxidation in the fetoplacental circulation in uncomplicated pregnancies.

Identification of extracapsular invasion of the metastatic lymph nodes as a useful prognostic sign in patients with resectable colorectal cancer

PURPOSE

The present study was undertaken to evaluate whether the microscopic patterns of distribution and extracapsular invasion of cancer cells in the regional lymph nodes were linked to the survival rates for patients with advanced colorectal cancer who undergo a curative surgical resection.

METHODS

Two hundred ninety-six surgically resected metastatic lymph nodes from 84 patients with node-positive colorectal cancer were microscopically examined. The distribution of cancer cells in the lymph nodes were grouped into two types: type A (> or =50 percent cancer) and type B (<50 percent cancer). The extracapsular invasion of cancer cells in the nodes were divided into three subgroups: pattern X (no evidence of cancer cell invasion into the adjacent tissue); pattern Y (less than five cancer cells were seen in the adjacent tissue); and pattern Z (more than five cancer cells invaded the adjacent tissue). The patients, based on these microscopic manifestations of metastatic patterns in the nodes, were divided into three groups: Group 1, patients with pattern X nodal metastases only; Group 2, patients with pattern Y and pattern (X + Y) nodal metastases; and Group 3, patients with pattern Z, pattern (X + Z), pattern (Y + Z), and pattern (X + Y + Z) nodal metastases.

RESULTS

The survival rates and disease-free survival rates for patients with metastatic lymph nodes showing an extracapsular invasion pattern (Groups 2 and 3) were significantly worse than those for patients with metastatic nodes showing no extracapsular invasion pattern only (Group 1; P < 0.01). There was no significant difference for the above-cited survival rates among the groups classified according to the Dukes and TNM systems.

CONCLUSIONS

It is the thesis of this article that the identification of extracapsular invasion of the metastatic lymph nodes can be taken as a useful prognostic sign in patients with resectable colorectal cancer.

A second primary esophageal cancer developing 7 years after chemoradiotherapy for advanced esophageal cancer

We report a rare case of advanced carcinoma and a second primary carcinoma of the esophagus, both of which were successfully cured by chemotherapy and operation at different times. In 1991, a 38-year-old Japanese man was diagnosed with advanced esophageal cancer, which was unresectable because of the bronchial invasion of the tumor. He was given chemotherapy with cisplatin (CDDP), combined with radiotherapy. During a 4-year follow-up, neither regrowth of the primary tumor nor distant metastasis occurred. In 1995, esophagoscopy demonstrated a lugol-unstained region located 3 cm distal from the area of radiation to the primary lesion shown by esophagography. Histological examination of a biopsy specimen showed the mucosa to be normal. Nevertheless, yearly surveillance by endoscopy and histological examinations showed that the mucosa of the esophagus gradually began to demonstrate mild dysplasia, followed by severe dysplasia; in 1998, a diagnosis of squamous cell carcinoma was made. Esophagectomy with lymph node dissection was performed. Microscopic examination revealed that there had been pathologic complete response for the original advanced esophageal cancer.

Changes in liver regenerative factors in a case of living-related liver transplantation

Liver regeneration in a patient with fulminant hepatic failure (FHF) who underwent living-related partial liver transplantation (LRLT) was investigated regarding hepatic growth factors. The patient was a 16-yr-old Japanese male who developed severe subacute FHF. LRLT was performed using an extended left lobe of the ABO matched patient's mother. In the recipient, the pre-transplant levels of both plasma hepatocyte growth factor (HGF) and transforming growth factor (TGF)-beta were extremely high and rapidly decreased following the liver replacement. The liver volume evaluated using a CAT scan increased 195% after 2 wk in graft liver and 110% after 2 wk in the hepatectomized donor. The explanted liver (FHF liver), the liver from donor (normal liver), and the graft liver [the 3rd post-transplant day (POD 3)] were all investigated immunohistochemically. FHF liver: No liver regeneration was observed [proliferative cell nuclear antigen (PCNA) labeling index (L.I.): 0%]. In the liver, both HGF in the hepatocytes and c-met on the membrane of the hepatocytes were positive. TGF-beta was positive in the hepatocytes and no apoptosis was detected by the TUNEL method. Donor liver (POD 0): Few PCNA stained hepatocytes were detected. No HGF was detected but c-met was clearly detected on the cell membrane of the hepatocytes. Neither TGF-beta nor apoptosis was detected. Graft liver (POD 3): The PCNA L.I. was conspicuous at 40%. HGF was positive in non-parenchymal cells and c-met was positive in the cytoplasm of the hepatocytes. TGF-beta was negative while apoptosis was positive in the zone 3 hepatocytes. In conclusion, these findings suggested that the liver of the patient with FHF did not respond to liver regenerative stimulus, in part, through involvement of inhibitor TGF-beta. On POD 3, the transplanted graft was in a vigorous regenerative status in comparison to that in the hepatectomized donor. The HGF/c-met system is thought to be involved in the mechanism of regeneration. Intrahepatic apoptosis was detected in the graft on the 3rd post-transplant day probably due to transient ischemia in the liver, which was not related to the Fas/Fas-ligand system.

Characteristics of monochorionic-diamniotic growth-retarded twins during the third trimester

The goal of this study was to assess the characteristics of monochorionic-diamniotic (MD) growth-retarded twin infants with twin-twin transfusion syndrome (TTTS) compared with those without TTTS during the third trimester. Retrospective analyses of the growth patterns and amniotic fluid volumes were performed on 5 MD twin pregnancies in which one or both twins showed growth retardation with TTTS, and the results weve compared with those without TTTS. Eighty-three percent of growth-retarded twin infants without TTTS in MD twin gestation showed an asymmetric growth pattern, while all TTTS cases showed a symmetric pattern (p < 0.05). Polyhydramnios of the co-twin was found in 80% of TTTS cases, while no polyhydramnios was found in patients without TTTS (p < 0.05). Assessment of growth patterns and amniotic fluid volume may be useful to exclude the possibility of TTTS in MD growth-retarded twin pregnancies during the third trimester.

Tetanus after a resection for a gangrenous perforated small intestine: report of a case

We report herein the case of a 75-year-old man who developed severe tetanus 24 h after the resection of a gangrenous perforated small intestine. It seemed that the tetanus was caused by a spillage of the intestinal contents harboring Clostridium tetani; however, this was not identified by a culture. The diagnosis of tetanus was made only when opisthotonus in this patient became evident and normal tetanus treatment proved to be successful.

[A case of partial Addison's disease activated with the administration of rifampicin (RFP)]

The patient was a 76 year-old female with tuberculous tendonitis, treated with anti-tuberculous drugs including rifampicin (RFP). About two weeks after the start of RFP, she noticed general malaise and started vomiting, and the laboratory data showed severe hyponatremia. Because of mild liver dysfunction, RFP was discontinued and her symptoms gradually improved. Abdominal X-ray and CT showed swellings and calcifications of adrenal glands bilaterally. Serum ACTH level was high and cortisole, 17-OHCS, and 17-KS levels were normal. Her response to rapid ACTH stimulation was blunted significantly. After another trial of RFP, she started to vomit and complain general malaise again. We diagnosed her as partial Addison's disease and administered hydrocortisone with RFP. After this treatment her improvement was rapid. It has been known that RFP causes induction of enzymes in hepatic microsomes which increase the catabolism of glucocorticoids. To avoid the risk of adrenal insufficiency, patients with insufficient adrenal hormone reserve should receive compensatory hydrocortisone while they are taking RFP.

Successful surgical treatment of gastric cancer with a tumor thrombus in the portal and splenic veins: report of a case

We report herein the case of a 70-year-old woman with histologically confirmed gastric Borrmann type 3 cancer in the posterior wall of the fundus in whom computed tomography demonstrated a dilated portal trunk and splenic vein containing a low-density mass, but no evidence of liver metastases. The venous phase of a superior mesenteric arteriogram subsequently showed occlusion of the main portal vein with venous collaterals. At surgery, a tumor thrombus was noted to extend from the short gastric vein to the portal vein via the splenic vein. Thus, an extensive gastric resection together with removal of the tumor thrombus from the veins was performed, and successful results were achieved.

[Diffuse aspiration bronchiolitis in an elderly woman]

A 74-year-old woman was admitted to the hospital because of persistent nocturnal coughing and abnormal shadows on chest x-ray films. The films showed cavities in the right upper lobe and small nodular shadows in the right upper, lower, and left upper lung fields. Examination of a specimen obtained by transbronchial lung biopsy showed nonspecific inflammatory changes. An open-lung biopsy was done. Histopathological examination showed evidence of diffuse aspiration bronchiolitis and actinomyces. Actinomyces is a member of the endogenous flora of the oral mucous membranes. Our diagnosis was diffuse aspiration bronchiolitis caused by micro-aspiration of oro-pharyngeal secretions during sleep.

CT of neural plexus invasion in common bile duct carcinoma

PURPOSE

Our purpose was to analyze the CT findings of neural plexus invasion in common bile duct carcinoma.

METHOD

We studied 16 patients with common bile duct carcinoma who underwent surgery. Of these, neural invasion was seen in 10 patients. CT findings were retrospectively reviewed and correlated with the surgical and pathological findings.

RESULTS

Irregular masses adjacent to the medial aspect of the uncinate process were observed in 4 of 14 patients with distal common bile duct carcinoma. These lesions extended medially and showed contiguity with the superior mesenteric artery and/or celiac axis, corresponding to neural plexus invasion with desmoplastic change. Increased attenuation of the fat between the common bile duct and the proper hepatic artery was seen in two of two patients with proximal common bile duct carcinoma, associated with neural plexus invasion in the hepatoduodenal ligament.

CONCLUSION

The location and spread of neural plexus invasion in common bile duct carcinoma are characteristic and can be diagnosed by CT.

Gastric cancer: evaluation of triphasic spiral CT and radiologic-pathologic correlation

PURPOSE

The purpose of this study was to evaluate the utility of triphasic spiral CT with water-filling method in the preoperative T staging of gastric cancer.

METHOD

We performed triphasic spiral CT in 108 patients with gastric cancer (53 with early and 55 with advanced gastric cancer). The CT findings were prospectively analyzed and correlated with the histopathologic findings. Spiral CT scans were assessed for the layered pattern of the normal gastric wall, the detectability of tumor, the enhancing pattern of the tumor, and the depth of tumor invasion.

RESULTS

The layered pattern of the normal gastric wall was clearly demonstrated in the arterial-dominant or parenchymal phase. All 12 early cancers detected with spiral CT were most clearly depicted in the arterial-dominant or parenchymal phase. On the other hand, 15 (28%) of 54 advanced cancers were most clearly depicted in the equilibrium phase due to the gradual enhancement from the inner mucosal side of the tumor. Most of these tumors were scirrhous type tumor containing abundant fibrous tissue stroma. The accuracy of spiral CT for tumor detection and T staging was 98 and 82%, respectively, in advanced gastric cancer and 23 and 15%, respectively, in early gastric cancer.

CONCLUSION

Spiral CT with triphasic scan technique improved the accuracy of estimating the depth of tumor invasion in advanced gastric cancer.

Seasonal variation in sweating responses of older and younger men

Eight older (60-65 years) and six younger (20-25 years) men were exposed to a standard heat stress for 60 min in summer, autumn, winter, and spring. The test consisted of placing the lower legs and feet in a 42 degrees C water bath while sitting in constant environmental conditions (30 degrees C and 45% relative humidity). The increase of rectal temperature (delta Tre) was significantly greater (P < 0.05) in autumn, winter, and spring than in summer for the older group, but significantly greater only in winter than in summer for the younger group (P < 0.05). The delta Tre was greater for the older group in all seasons, but of significance only in autumn and spring (P < 0.01). There were no significant season-related differences for metabolic heat production (M) and mean skin temperature (Tsk) during the heat test in the respective groups, although the M and Tsk were lower for the older group in all seasons (P < 0.01). In the older group total body sweating rate (msw) divided by delta Tre (total msw/delta Tre) decreased from summer to winter (P < 0.02) and did not differ between winter and spring, whereas total msw/delta Tre in the younger group increased in spring after decreasing from autumn to winter (P < 0.03). The variations of the value, local sweating rate on the back and thigh divided by delta Tre (back msw/delta Tre and thigh msw/delta Tre), were similar to those of the total msw/delta Tre in each group, except for back msw/delta Tre in the younger group, which did not increase from winter to spring.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenomatous hyperplasia in the vicinity of small hepatocellular carcinoma

The nodular lesions seen in the noncancerous areas of the 80 consecutively resected small hepatocellular carcinoma associated with cirrhosis were pathomorphologically studied. A total of 51 nodular lesions were found, and they were classified into the following four groups: large regenerative nodule (30 nodules), adenomatous hyperplasia (12 nodules), atypical adenomatous hyperplasia (4 nodules) and adenomatous hyperplasia containing cancerous foci (5 nodules). Grossly, all large regenerative nodules were well demarcated, but some of the adenomatous hyperplasia group were vaguely nodular. Atypical adenomatous hyperplasia and adenomatous hyperplasia containing cancerous foci accounted for 43% of the adenomatous hyperplasia group found in the vicinity of the 16 resected hepatocellular carcinoma (20%) out of 80 cases. The mean size (+/- S.D.) of the adenomatous hyperplasias containing cancerous foci, 15.8 +/- 2.2 mm, was significantly larger than 10.1 +/- 2.6 mm of the adenomatous hyperplasias p less than 0.01). All adenomatous hyperplasias containing cancerous foci and 75% of the atypical adenomatous hyperplasias demonstrated a marked fatty change, but none of the large regenerative nodules were accompanied by any fatty changes. This study demonstrated the morphological transition from adenomatous hyperplasia to hepatocellular carcinoma that was suggestive of multistep hepatocarcinogenesis. As a result, it is predicted that approximately 20% of all hepatocellular carcinomas may have the potential for being of multicentric origin and that approximately 40% of adenomatous hyperplasias may undergo malignant transformation, but it is difficult to estimate the exact number of incidences. The presence of varying degrees of fatty change may be one of the significant morphological markers for a malignant transformation from adenomatous hyperplasia to hepatocellular carcinoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on thromboplastic and fibrinolytic activities of valvular tissue in rheumatic valvular disease

While rheumatic valvular disease (RVD) is known to develop subsequent to rheumatic carditis, we examined whether in addition to the inflammatory and repair process, thromboplastic and fibrinolytic activities of the valvular tissue play a contributory role in the pathogenesis of RVD. Both activities were higher in resected valves from RVD cases than in the controls. Tissue thromboplastin was localized in the valvular endothelium and the subendothelial connective tissue. Tissue fibrinolytic activity was prevalent in the small blood vessels of RVD valves, while it was lower on the surface of RVD valves than in the controls. High thromboplastic and low fibrinolytic activity in the surface layer of RVD valves may accelerate the deposition of thrombi, thereby inducing valvular thickening.