Pneumocystis jirovecii pneumonia after CD4+ T-cell recovery subsequent to CD19-targeted chimeric antigen receptor T-cell therapy: A case report and brief review of literature

BACKGROUND

CD19-targeted chimeric antigen receptor (CAR)-T cell therapy involves administration of patient-derived T cells that target B cells, resulting in B-cell depletion and aplasia. In immunity against Pneumocystis jirovecii (Pj), CD4+ T cells and, more recently, B cells, are generally considered important. Antigen presentation by B cells to CD4+ T cells is particularly important. Trimethoprim-sulfamethoxazole (TMP/SMX) for Pj pneumonia (PJP) prophylaxis is generally discontinued when the CD4+ T-cell count is >200/μL. Here we report the first case, to our knowledge, of PJP in a patient with a CD4+ T cell count of >200/μL after CAR-T cell therapy.

CASE

A 14-year-old girl developed hemophagocytic lymphohistiocytosis (HLH) after cord blood transplantation (CBT) for relapsed precursor B-cell acute lymphoblastic leukemia (B-ALL). Twenty-one months after CBT, she was diagnosed with combined second relapse in the bone marrow and central nervous system. The patient was treated with CD19-targeted CAR-T cell therapy for the relapse. After CAR-T cell therapy, the patient remained in remission and continued to receive TMP/SMX for PJP prophylaxis. Seven months after CAR-T cell therapy, CD4+ T cells recovered and TMP/SMX was discontinued. The B-cell aplasia persisted. Ten months after CAR-T cell therapy, the patient developed PJP. The patient was also considered to have macrophage hyperactivation at the onset of PJP. Treatment with immunoglobulin, TMP/SMX, and prednisolone was initiated, and the patient's symptoms rapidly ameliorated.

CONCLUSION

The patient in the present case developed PJP despite a CD4+ T-cell count of >200/μL after CAR-T cell therapy, probably because of inadequate CD4+ T-cell activation caused by B-cell depletion after CAR-T cell therapy and repeated abnormal macrophage immune responses after CBT. It is important to determine the duration of TMP/SMX for prophylaxis after CAR-T cell therapy according to each case, as well as the CD4+ T-cell count.

Pediatric Precision Medicine at the National Cancer Center Japan: Prospective Genomic Study of Pediatric Patients with Cancer as Part of the TOP-GEAR Project

PURPOSE

This single-center, prospective molecular profiling study characterizes genomic alterations and identifies therapeutic targets in advanced pediatric solid tumors.

METHODS

As part of the TOP-GEAR (Trial of Onco-Panel for Gene profiling to Estimate both Adverse events and Response by cancer treatment) project at the National Cancer Center (NCC), Japan, we enrolled pediatric patients with a refractory or recurrent disease during August 2016-December 2021 and performed genomic analysis of matched tumors and blood using originally developed cancer gene panels, NCC Oncopanel (ver. 4.0) and NCC Oncopanel Ped (ver. 1.0).

RESULTS

Of 142 patients (age, 1-28 years) enrolled, 128 (90%) were evaluable for genomic analysis; 76 (59%) patients harbored at least one reportable somatic or germline alteration. The tumor samples were collected during the initial diagnosis in 65 (51%) patients, after treatment initiation in 11 (9%) patients, and upon either disease progression or relapse in 52 (41%) patients. The leading altered gene was TP53, followed by MYCN, MYC, CDKN2A, and CDK4. The commonly affected molecular processes were transcription, cell-cycle regulation, epigenetic modifiers, and RAS/mitogen-activated protein kinase signaling. Twelve (9%) patients carried pathogenic germline variants in cancer-predisposing genes. Potentially actionable findings were identified in 40 (31%) patients; to date, 13 (10%) patients have received the recommended therapy on the basis of their genomic profiles. Although four patients had access to targeted therapy through clinical trials, the agents were used in nine patients in an off-label setting.

CONCLUSION

The implementation of genomic medicine has furthered our understanding of tumor biology and provided new therapeutic strategies. However, the paucity of proposed agents limits the full potential of actionability, emphasizing the significance of facilitating access to targeted cancer therapies.

A 15-Year-Old Boy with Primary Maxillary Bone Anaplastic Lymphoma Kinase-Positive Anaplastic Large Cell Lymphoma Relapsed with Rib Metastasis after Spontaneous Remission of a Maxillary Bone Lesion: A Case Report and Literature Review

Anaplastic large cell lymphoma (ALCL) is a rare form of non-Hodgkin's lymphoma (NHL) in children, accounting for 10-15% of all NHL cases. ALCL is currently classified as follows: systemic anaplastic lymphoma kinase (ALK)-positive, systemic ALK-negative, primary cutaneous, and breast implant-associated ALCL. In children, systemic ALK-positive ALCL is the most common, and patients often present with extranodal involvement. We report a rare case of systemic ALK-positive ALCL with primary bone involvement in a 15-year-old male patient. Primary bone lymphoma is most commonly observed in diffuse large B-cell lymphoma and is extremely rare in systemic ALCL. Therefore, the clinical features and prognosis of primary bone ALCL remain unclear. Our patient had spontaneous remission of primary maxillary bone ALCL after gingival scraping but relapsed 12 months later with rib metastasis. Spontaneous remission of ALCL has been reported frequently in primary cutaneous ALCL and rarely in systemic ALCL. Our case demonstrates for the first time that systemic ALCL can also present as solitary bone involvement that can spontaneously remit. Because systemic ALCL is aggressive and has a risk of relapse, as in our case, it is important to consider ALCL in the differential diagnosis of primary bone lesions and to make a precise pathological diagnosis.

Cervical Edema Extending to the Larynx as Local Cytokine Release Syndrome Following Chimeric Antigen Receptor T-Cell Therapy in a Boy with Refractory Acute Lymphoblastic Leukemia

Cytokine release syndrome (CRS) is one of the major acute complications caused by massive cytokine release after chimeric antigen receptor (CAR) T-cell therapy. Patients with tumor masses were considered at high risk of local CRS induced by the expansion of CAR T cells in the tumor masses. However, even patients without any tumor burden around the neck are at risk of developing cervical edema as local CRS, which can lead to life-threatening airway obstruction. Here, we present the case of a 15-year-old boy who developed cervical edema as a local CRS after CAR T-cell therapy for refractory acute lymphoblastic leukemia. Despite administration of tocilizumab and methylprednisolone for persistent fever as a symptom of systemic CRS after CAR T-cell therapy, cervical edema occurred and extended to the larynx, resulting in dysphagia and hoarseness. Dexamethasone was remarkably effective, and the laryngeal symptoms resolved within a few hours. Local cytokine syndrome showed exacerbation with tocilizumab but exhibited considerable improvement with dexamethasone administration.

Medical guidelines for Li-Fraumeni syndrome 2019, version 1.1

Li–Fraumeni syndrome (LFS) is a hereditary tumor that exhibits autosomal dominant inheritance. LFS develops in individuals with a pathogenic germline variant of the cancer-suppressor gene, TP53 (individuals with TP53 pathogenic variant). The number of individuals with TP53 pathogenic variant among the general population is said to be 1 in 500 to 20,000. Meanwhile, it is found in 1.6% (median value, range of 0–6.7%) of patients with pediatric cancer and 0.2% of adult patients with cancer. LFS is diagnosed by the presence of germline TP53 pathogenic variants. However, patients can still be diagnosed with LFS even in the absence of a TP53 pathogenic variant if the familial history of cancers fit the classic LFS diagnostic criteria. It is recommended that TP53 genetic testing be promptly performed if LFS is suspected. Chompret criteria are widely used for the TP53 genetic test. However, as there are a certain number of cases of LFS that do not fit the criteria, if LFS is suspected, TP53 genetic testing should be performed regardless of the criteria. The probability of individuals with TP53 pathogenic variant developing cancer in their lifetime (penetrance) is 75% for men and almost 100% for women. The LFS core tumors (breast cancer, osteosarcoma, soft tissue sarcoma, brain tumor, and adrenocortical cancer) constitute the majority of cases; however, various types of cancers, such as hematological malignancy, epithelial cancer, and pediatric cancers, such as neuroblastoma, can also develop. Furthermore, approximately half of the cases develop simultaneous or metachronous multiple cancers. The types of TP53 pathogenic variants and factors that modify the functions of TP53 have an impact on the clinical presentation, although there are currently no definitive findings. There is currently no cancer preventive agent for individuals with TP53 pathogenic variant. Surgical treatments, such as risk-reducing bilateral mastectomy warrant further investigation. Theoretically, exposure to radiation could induce the onset of secondary cancer; therefore, imaging and treatments that use radiation should be avoided as much as possible. As a method to follow-up LFS, routine cancer surveillance comprising whole-body MRI scan, brain MRI scan, breast MRI scan, and abdominal ultrasonography (US) should be performed immediately after the diagnosis. However, the effectiveness of this surveillance is unknown, and there are problems, such as adverse events associated with a high rate of false positives, overdiagnosis, and sedation used during imaging as well as negative psychological impact. The detection rate of cancer through cancer surveillance is extremely high. Many cases are detected at an early stage, and treatments are low intensity; thus, cancer surveillance could contribute to an improvement in QOL, or at least, a reduction in complications associated with treatment. With the widespread use of genomic medicine, the diagnosis of LFS is unavoidable, and a comprehensive medical care system for LFS is necessary. Therefore, clinical trials that verify the feasibility and effectiveness of the program, comprising LFS registry, genetic counseling, and cancer surveillance, need to be prepared.

Thiotepa-melphalan myeloablative therapy for high-risk neuroblastoma

BACKGROUND

Appropriate high-dose chemotherapy (HDC) for high-risk neuroblastoma has not yet been established. In Japan, a unique HDC regimen that comprises two cycles of a total of 800 mg/m² of thiotepa and a total of 280 mg/m² of melphalan is widely utilized.

METHODS

To evaluate the safety and efficacy of this thiotepa-melphalan high-dose therapy for high-risk neuroblastoma, we reviewed the medical records of 41 patients with high-risk neuroblastoma who underwent this regimen followed by autologous peripheral blood stem cell rescue between 2002 and 2012. MYCN-amplified high-risk neuroblastomas were observed in 23 patients. All patients underwent intensive multidrug induction chemotherapy, but none underwent anti-GD2 antibody immunotherapy. The primary tumor was resected at the adequate time point.

RESULTS

The median follow-up duration for living patients was 9.2 years (range 5.5-14.0 years). The 5-year event-free survival (EFS) and overall survival from treatment initiation were 41.5 ± 7.7% and 56.1 ± 7.8%, respectively. The 5-year EFS of MYCN-amplified high-risk neuroblastoma patients was 60.9 ± 10.2%, which was significantly superior compared with those with MYCN-nonamplified high-risk neuroblastoma (16.7 ± 8.8%; p < .001). MYCN amplification was the most favorable prognostic factor for EFS (hazard ratio = 0.29; 95% confidence interval = 0.12-0.66). Of the 41 patients, three died because of regimen-related toxicity (infection, n = 2; microangiopathy, n = 1).

CONCLUSION

The thiotepa-melphalan high-dose therapy with thiotepa and melphalan may be effective for high-risk neuroblastoma. However, this regimen is toxic and warrants special attention in clinical practice.

Characteristics of Li-Fraumeni Syndrome in Japan; A Review Study by the Special Committee of JSHT

Li-Fraumeni syndrome (LFS) is a hereditary cancer predisposition syndrome, and the majority of patients with LFS have been identified with germline variants in the p53 tumor suppressor (TP53) gene. In the past three decades, considerable case reports of TP53 germline variants have been published in Japan. To the best of our knowledge, there have been no large-scale studies of Japanese patients with LFS. In this study, we aimed to identify Japanese patients with TP53 germline variants and to reveal the characteristics of LFS in Japan. We collected reported cases by reviewing the medical literature and cases diagnosed at the institutions of the authors. We identified 68 individuals from 48 families with TP53 germline pathogenic or likely pathogenic variants. Of the 48 families, 35 (72.9%) had missense variants, most of which were located within the DNA-binding loop. A total of 128 tumors were identified in the 68 affected individuals. The 128 tumor sites were as follows: breast, 25; bones, 16; brain, 12; hematological, 11; soft tissues, 10; stomach, 10; lung, 10; colorectum, 10; adrenal gland, 9; liver, 4; and others, 11. Unique phenotype patterns of LFS were shown in Japan in comparison to those in a large national LFS cohort study in France. Above all, a higher frequency of patients with stomach cancer was observed in Japanese TP53 germline variant carriers. These results may provide useful information for the clinical management of LFS in Japan.

Severe bloody diarrhea due to cytokine release syndrome after chimeric antigen receptor T cell therapy for refractory acute lymphoblastic leukemia

Cytokine release syndrome (CRS), which may be associated with fever, hypotension, hypoxia, and organ damage, is caused by a massive cytokine release after chimeric antigen receptor (CAR)-T cell therapy. We present the case of a patient who developed severe bloody diarrhea due to CRS after CAR-T cell infusion. A 10-year-old boy presented with a second relapse of B-cell precursor acute lymphoblastic leukemia 6 months after hematopoietic stem cell transplantation from an unrelated donor. CAR-T cells (tisagenlecleucel) were infused at the third complete remission after salvage chemotherapy. While fever >39°C was sustained from day 4, circulatory and respiratory status remained stable. However, he experienced severe bloody diarrhea. There was no evidence of infection; lower gastrointestinal (GI) endoscopy revealed extensive edema with erosion and ulceration, suggestive of non-specific intestinal inflammation. Thus, we considered CRS-associated grade 3 GI damage and administered a single dose of tocilizumab for grade 2 CRS, followed by 4 days of corticosteroids. Afterwards, no fever or GI bleeding was observed. Biopsy of the intestinal mucosa revealed ulcerative change with a lack of epithelial cells, which may correspond to histologic grade 4 graft versus host disease (GVHD). However, diarrhea corresponded to stage 1 GVHD, and the GVHD risk after CAR-T cell infusion has been reported to be rare in clinical practice. Although severe GI symptoms associated with CRS after CAR-T therapy are rare, early tocilizumab use is recommended for non-infectious severe GI symptoms to avoid long-term corticosteroid use, which may reduce CAR-T cell efficacy.

Progressive cerebral and coronary aneurysms in the original two patients with Kosaki overgrowth syndrome

Skeletal overgrowth accompanied by de novo heterozygous activating mutations in PDGFRB (platelet-derived growth factor receptor beta), that is, p.Pro584Arg and p.Trp566Arg, defines Kosaki overgrowth syndrome (OMIM #616592). Emerging evidence suggests a role of PDGFRB in the genesis of cerebral aneurysms. The delineation of the range and progression of the vascular phenotype of Kosaki overgrowth syndrome is urgently needed. Herein, we conducted subsequent analyses of serial neurovascular imaging studies of two original patients with a de novo heterozygous mutation in PDGFRB, that is, p.Pro584Arg. The analysis showed the progressive dilation of basilar and vertebral arteries and coronary arteries commencing during the teenage years and early 20s. The radiographic appearance of the basilar vertebral aneurysms showed signs of arterial wall dilation, compatible with the known vascular pathology of vascular-type Ehlers-Danlos syndrome and Loeys-Dietz syndrome. The dolichoectasia in cerebrovascular arteries can lead to fatal complications, even with neurosurgical interventions. To prevent the progression of artery dilation, preventative and therapeutic medical measures using tyrosine kinase inhibitors may be necessary in addition to optimal control of the systemic blood pressure. Kosaki overgrowth syndrome is a clinically recognizable syndrome that can exhibit progressive dilatory and tortuous vascular changes in basilar/vertebral and coronary arteries as early as in the teenage years. We recommend careful counseling regarding the risk of future vascular complications, optimal blood pressure control, and regular systemic vascular screening during follow-up examinations.

Central nervous system ganglioneuroblastoma harboring MYO5A-NTRK3 fusion

Central nervous system (CNS) ganglioneuroblastoma is a rare neuroectodermal neoplasm and little is known about its clinical and biological features. Herein, we report a pediatric case of CNS ganglioneuroblastoma harboring MYO5A-NTRK3 fusion. The patient, a 4-year-old boy, underwent a partial resection of a supratentorial tumor that was histopathologically diagnosed as a CNS ganglioneuroblastoma. Treatment with radiotherapy was started per the St Jude Medulloblastoma 03 (SJMB03) protocol; however, the tumor progressed rapidly and radiotherapy was temporally discontinued. Meanwhile, the patient underwent a second surgery, in which a gross total resection was successfully performed, following which he completed the remaining protocol-based therapy. Although an early focal recurrence was detected for which he received additional radiotherapy and oral temozolomide, the patient remained in complete remission for 14 months after the completion of the treatment. A central pathological review and molecular analysis were performed that revealed a MYO5A-NTRK3 fusion. Interestingly, the MYO5A-NTRK3 fusion has been recurrently detected in melanocytic tumors but not in other types of tumors. Therefore, it can be speculated that our case might partly share tumorigenesis mechanisms with MYO5A-NTRK3-positive melanocytic tumors. In addition, our case may enable an improved understanding of the pathogenesis and clinical features of CNS ganglioneuroblastomas.

Successful treatment with hydroxychloroquine for systemic lupus erythematosus with cutaneous involvement accompanied by a xanthomatous reaction

Antimalarials are usually recommended for the first-line systemic treatment of cutaneous lupus erythematosus. Alopecia in patients with discoid lupus erythematosus (DLE) is sometimes a refractory condition in spite of topical therapies. We herein described a case of DLE on the scalp with a pathological change of a xanthomatous reaction, which was successfully treated with hydroxychloroquine (HCQ). A 34-year-old woman presented with hair loss to the parietal region. She had been diagnosed with systemic lupus erythematosus (SLE) four years previously. Treatment with 30 mg/day of prednisolone (PSL) had been initiated, and the dose was gradually reduced. At 10 mg/day of PSL, she had noticed her hair loss. Physical examination revealed some small erythematous lesions to the parietal region with accompanying hair loss. Pathological findings of the erythematous lesion on her head revealed thickening of the basement membrane zone, the interface dermatitis with vacuolar degeneration, and both superficial perivascular and perifollicular infiltration of inflammatory cells in the dermis. In addition, there was an infiltrate of xanthomatous cells detected in the papillary dermis, which were positive for CD68 and CD163. The patient started treatment with HCQ at a dose of 200 mg/day. The skin lesions completely resolved within five months after initiation of HCQ without increase in the dose of PSL. Xanthomatous reactions are rarely recognized in lupus erythematosus. The chronic epithelial injury in DLE could be implicated in triggering the secondary reactive process of a xanthomatous reaction. We believe that the reaction seen in our patient was a secondary change to pathological alteration due to SLE. However, as yet unrecognized factors may play a role in the development of a xanthomatous reaction in DLE.

Validation of Real-Time PCR Analyses for Line-Specific Quantitation of Genetically Modified Maize and Soybean UsingNew Reference Molecules

Novel analytical methods based on real-time quantitative polymerase chain reactions by use of new reference molecules were validated in interlaboratory studies for the quantitation of genetically modified (GM) maize and soy. More than 13 laboratories from Japan, Korea, and the United States participated in the studies. The interlaboratory studies included 2 separate stages: (1) measurement tests of coefficient values, the ratio of recombinant DNA (r-DNA) sequence, and endogenous DNA sequence in the seeds of GM maize and GM soy; and (2) blind tests with 6 pairs of maize and soy samples, including different levels of GM maize or GM soy. Test results showed that the methods are applicable to the specific quantitation of the 5 lines of GM maize and one line of GM soy. After statistical treatment to remove outliers, the repeatability and reproducibility of these methods at a level of 5.0% were &lt;13.7 and 15.9%, respectively. The quantitation limits of the methods were 0.50% for Bt11, T25, and MON810, and 0.10% for GA21, Event176, and Roundup Ready soy. The results of blind tests showed that the numerical information obtained from these methods will contribute to practical analyses for labeling systems of GM crops.

Haploidentical stem cell transplantation with posttransplant cyclophosphamide for refractory systemic juvenile xanthogranuloma

Juvenile xanthogranuloma (JXG) is a generally benign, self-limited histiocytic disorder, which belongs to non-Langerhans cell histiocytoses (non-LCH). However, systemic JXG can be fatal in rare cases. We present the case of an 11-year-old female with systemic JXG, who experienced repeated vertebral compression fractures and did not fully respond to systemic chemotherapy. Based on its reported efficacy in LCH, the patient underwent human leukocyte antigen-haploidentical hematopoietic stem cell transplantation (HSCT) with posttransplant cyclophosphamide. The patient did not suffer major complications and has not experienced relapse for 13 months since HSCT. HSCT may be a potential treatment option for patients with refractory non-LCH.

Palisaded neutrophilic and granulomatous dermatitis associated with systemic lupus erythematosus: possible involvement of CD163+ M2 macrophages in two cases, and a review of published works

BACKGROUND

Palisaded neutrophilic and granulomatous dermatitis (PNGD) is a commonly occurring condition related to systemic autoimmune disease. It is characterized histopathologically by a distinct pattern of granulomatous inflammation in the presence or absence of leukocytoclastic vasculitis. The properties of granulomatous cells in PNGD are still uncertain.

OBJECTIVE

We sought further investigation on the phenotype of the infiltrated cells in PNGD from two patients with systemic lupus erythematosus (SLE) and reviewed the previous published reports in order to provide a comprehensive summary on the clinical features of PNGD in SLE.

METHODS

The immunohistochemical features of granulomatous cells in PNGD associated with SLE were analyzed. Immunohistochemical studies were performed on sections from our two cases using antibodies against CD68, CD163, CD15, Factor XIIIa, myeloperoxidase and neutrophil elastase. The clinical characteristics of the SLE patients who developed PNGD were also evaluated. We included all cases retrieved through a PubMed search with the key words PNGD and SLE.

RESULTS

Cutaneous lesions consisted of erythematous plaques distributed on the face and upper limbs in both cases. The infiltrated cells were mainly positive for CD68 and CD163, a phenotype suggestive of M2 macrophages. Some mature neutrophils and lymphocytes were also present. A review of the literature of PNGD associated with SLE revealed a predominance in females, high prevalence of lupus nephritis and a good response to systemic steroids, with frequent skin lesions relapses during tapering of the treatment.

LIMITATIONS

This study examined only two cases; the pathogenesis of the disease remains to be clarified.

CONCLUSION

PNGD lesions were abundantly infiltrated by M2 macrophages, suggesting that they may have a role in this condition. SLE accompanied by PNGD might be associated with lupus nephritis and frequent relapses of skin lesions.

Successful treatment of metastatic rhabdomyosarcoma with radiochemotherapy and allogeneic hematopoietic stem cell transplantation

We report a case of a 21-year-old man with alveolar rhabdomyosarcoma primarily in the right hand with lymph node, lung, bone and bone marrow metastases. Complete remission was achieved after intensive chemotherapy and radiotherapy of the primary and metastatic sites, followed by allogeneic peripheral blood stem cell transplantation with reduced-intensity conditioning from a single HLA-DR locus-mismatched mother. The patient remained relapse-free for 41 months after the diagnosis. Considering that the conventional treatment for rhabdomyosarcoma with multiple risk factors (old age, bone or bone marrow involvement, unfavorable primary sites and ≥ 3 metastases) is associated with a poor prognosis (5% probability of a 3-year event-free survival), the graft-versus-tumor effect may have contributed to his sustained relapse-free survival. Allogeneic hematopoietic stem cell transplantation for rhabdomyosarcoma should be done by experienced clinical oncologists on properly designed controlled trials.

Two cases of neuroblastoma comprising two distinct clones

We report two cases of high-risk metastatic neuroblastoma, comprising two biologically distinct components in the adrenal primary tumor, which showed clear differences not only histologically but also in MYCN amplification and HA-RAS/TRKA immunoreactivity (Case 1), anaplastic lymphoma kinase (ALK) immunoreactivity (Case 2). These two cases with multiple separated components were similar to cases classified as ganglioneuroblastoma, nodular subtype (GNBn), in terms of composite tumor. Comparable to the GNBn category, the prognosis of the patients described here may depend on the components with unfavorable histology according to International Neuroblastoma Pathology Classification. Further analyses of such composite neuroblastoma cases are important for assessing disease prognosis.

[The third repair for pseudoaneurysm following Bentall procedure: report of a case]

A 77-year-old male, who had undergone the Bentall procedure 27 years ago, was admitted to our hospital for the repair of postoperative pseudoaneurysm. This was the 3rd repair, and the pseudoaneurysm was close to the sternum. Total extracorporeal circulation was established with femorofemoral cannulation and sternotomy was performed under deep hypothermia. During sternotomy, we encountered massive hemorrhage due to injury of the aortic graft. We coped effectively with the situation utilizing temporary circulatory arrest. Aortic graft reimplantation was performed under continuous retrograde cerebral perfusion. Collapse of the suture line of the left coronary orifice was recognized and was reconstructed. The patient was discharged uneventfully on the 26th postoperative day.

[Clinical outcome of aortic valve replacement with 19-mm prosthetic valve in elderly patients]

From 1979 to June 2005, 90 patients aged 65 or older underwent aortic valve replacement with 19-mm prosthetic valve. They were 84 women and 6 men, with a mean age of 74. The mean body surface area was 1.35 m2. Bioprosthetic valves were implanted in 77 patients (85.6%). In-hospital mortality was 2.2% (2 of 90). There were 13 late deaths. New York Heart Association (NYHA) functional class improved to class I in most of survivors. Survival rates for 5 and 10 years were 84.9 and 71.2%, respectively. The outcome of aortic valve replacement with 19-mm prosthetic valve in elderly patients was excellent.

Autonomic Heart Rate Regulation during Mild Dynamic Exercise in Humans: Insights from Respiratory Sinus Arrhythmia

To better understand the neural mechanism of heart rate (HR) regulation during dynamic exercise, the responses of HR and the magnitude of respiratory R-R interval variation were examined during exercise and recovery at mild intensities in humans. Eight subjects performed 3-min constant load cycle exercises in a semi-supine position at work rates of 25, 50, and 100 W. The respiratory interval was fixed at 4 s. Peak-to-valley variation in R-R interval caused by respiration was measured breath-by-breath and standardized for tidal volume (DeltaRRst, a noninvasive index of the degree of parasympathetic cardiac control). At all work rates the HR increased significantly from 2.5 s after the beginning of exercise (p <0.05) and decreased temporarily and slightly at around 15 s, and the DeltaRRst varied almost inversely. The HR and the DeltaRRst until 12.5 s after the beginning of exercise changed independently of work rate (ANOVA, p=0.27 and p=0.08). The HR-DeltaRRst relationship at the initial phase of exercise (for 12.5 s) was almost the same at all work rates. These results suggest that the initial HR response to exercise is strongly parasympathetically regulated independently of work rate. The HR recovered slower than the DeltaRRst at 50 and 100 W. On the HR-DeltaRRst relationship, the HR during recovery was significantly higher than during exercise at 1/3, 1/2, and 2/3 levels of pre-exercise DeltaRRst at 50 and 100 W and at the 1/3 level at 25 W (p < 0.05). At 25 W, the difference in HR at the 1/3 level was 5.5 beats.min(-1), and the HR increase to exercise was 21.2 beats.min(-1). We suggest that a HR regulatory system responds slower than a cardiac parasympathetic system to exercise, a cardiac sympathetic system, is activated even during mild exercise in humans.

Epinastine Inhibits Eosinophil Chemotaxis and Adhesion Molecules in Atopic Dermatitis

PURPOSE

To investigate the effects of epinastine on eosinophil chemotaxis and changes in eosinophil adhesion molecules induced by epinastine and three other antiallergic agents, using eosinophils of atopic dermatitis (AD) patients.

RESULTS

Epinastine reduced eosinophil chemotaxis toward eotaxin when the eosinophils had been prestimulated with interleukin (IL)-5, but given alone it did not alter eosinophil chemotaxis toward IL-5. CD11b expression was inhibited when peripheral blood was prestimulated with IL-5, but eosinophil adhesion molecule expression was not altered.

CONCLUSIONS

Epinastine suppresses allergic inflammation not only through its strong antihistamine and antimediator effects, but also by inhibiting eosinophilic chemotaxis and the expression of adhesion molecules involved in chemotaxis, especially CD11b.

[Surgical treatment of Marfan syndrome; analysis of the patients required multiple surgical interventions]

Without treatment, the life expectancy of patients with Marfan syndrome is reduced by the associated cardiovascular abnormalities. In this study, we reviewed our experience of the patients with Marfan syndrome who required multiple surgical interventions to identify the optimal treatment for these patients. Between January 1986 and December 2000, 44 patients with Marfan syndrome were operated on at Shizuoka City Hospital (SCH). Among them, 10 patients (22.7%) underwent multiple surgical interventions. There were 5 male and 5 female patients with a mean age of 40.6 +/- 16.1 years at the initial surgery. Only one patient was operated on at another hospital for his first, second, and third operations. His fourth operation was carried out at SCH. The remaining 9 patients underwent a total of 14 additional surgical procedures at SCH. Computed tomography (CT) scans were taken every 6 months postoperatively, and aortic diameter greater than 60 mm was considered as the indication for the additional surgery. There were no early death and one late death. The causes of additional surgery were enlargement of true aneurysm in 6, enlargement of residual dissection in 4, new dissection in 4, false aneurysm at the coronary anastomosis of Bentall procedure in 1. In 9 patients, both ascending and descending aorta were replaced. Among these 9 patients, only 3 patients underwent total arch replacement, and remaining 6 patients had their arch left in place with or without dissection. Our current strategy of the treatment of Marfan patients with acute type A dissection is total arch replacement with an elephant trunk at the initial emergent surgery.

[Long-term results after surgery for aortic arch nondissection aneurysm]

Between 1990 and August 2001, 109 patients were treated surgically for nondissection fusiform or saccular aortic arch aneurysm. Fifteen patients were emergent. There were 89 male and 20 female patients (mean 71.7 +/- 6, range 49 to 84). Eight patients underwent hemiarch replacement, 57 total arch replacement, 44 distal arch replacement, which were performed with the aid of hypothermic extracorporeal circulation with antegrade selective cerebral perfusion or retrograde cerebral perfusion. The early mortality was 8.5% with elective operations and 53.3% with emergent operations. The incidence of post operative permanent neurological dysfunction was 12.8% with elective operations and 46.7% with emergent operations. The 5-year and 10-year survival rate including in-hospital deaths was 52 +/- 6% and 29 +/- 9%. The 5-year event free rate was 89 +/- 5%.

Hypovolemic intolerance to lower body negative pressure in female runners

PURPOSE

An attenuated baroreflex response and orthostatic intolerance have been reported in endurance-trained male athletes; however, it is still unknown whether this occurs also in females. The purpose of the present study was to examine whether endurance exercise-trained women had a predisposition to orthostatic compromise, and if so, what causative factor(s) may induce orthostatic intolerance.

METHODS

We studied cardiovascular and hormonal responses to graded lower body negative pressure (LBNP) (0 to -60 mm Hg) in 26 middle-distance female runners (18.6 +/- 0.1 yr) as the exercise-trained (ET) subjects and 23 age-matched untrained (UT) control subjects. On the basis of the occurrence of syncope episodes during LBNP, ET and UT subjects were further allocated to two groups; ET with presyncope (ET+syncope) and without presyncope (ET-syncope) and UT with presyncope (UT+syncope) and without presyncope (UT-syncope).

RESULTS

Occurrence of presyncope episodes during LBNP was higher in ET (65.4%, P < 0.05) than that for UT (34.8%). Leg compliance was higher (P < 0.05) in ET than in UT. LBNP reduced stroke volume (SV) more (P < 0.05), increased heart rate (HR) higher (P < 0.05), and increased forearm vascular resistance (FVR) more in ET+syncope as compared with the other groups. Response of vasoactive hormones to LBNP was higher in ET+syncope (P < 0.05) than that of the other groups except for norepinephrine (NE); high in both ET+syncope and UT+syncope. The relationship between SV and NE, an index of sympathetic neuronal response, had no training-related changes during LBNP.

CONCLUSION

We conclude that exercise-trained females have a high incidence of orthostatic intolerance during LBNP, with a greater reduction of SV independent of changes in baroreflex and neurohumoral function. A lower incidence of LBNP intolerance in UT may be accounted for by a lower reduction of SV during LBNP. An increase in leg compliance in the exercise-trained females may play an important role in inducing pronounced reduction of SV and hence the intolerance to LBNP.

Immunohistochemical detection for nuclear beta-catenin in sporadic basal cell carcinoma

BACKGROUND

Despite the increasing incidence of basal cell carcinoma (BCC), its pathogenesis has remained largely unknown. Recently, it was reported that genes involved in tissue morphogenesis, such as sonic hedgehog or patched, were found to be mutated in BCC, suggesting the involvement of those molecules in the pathogenesis of this tumour. Furthermore, there is evidence that the Wnt-mediated signalling pathway may be one of the downstream targets of sonic hedgehog-mediated signalling, which has led us to focus on molecular events on the Wnt pathway in BCC. Among the signal transducers involved in the Wnt pathway, it is clear that beta-catenin plays a pivotal role in the promotion of morphogenesis and cell growth. In respect to this, it has been reported that, in particular circumstances, as in colorectal cancers, beta-catenin migrates to the nuclei, where it exerts an ability to activate the transcription of various genes.

OBJECTIVES

To investigate the cellular distribution of beta-catenin in skin tumours, in particular, in BCC.

METHODS

Twenty skin biopsy specimens derived from BCC, 10 from inflammatory skin diseases and five from squamous cell carcinomas were immunostained with an antibody directed against beta-catenin.

RESULTS

Fourteen of the 20 BCC samples tested showed nuclear localization of beta-catenin, while none of the other samples gave rise to positive nuclear staining.

CONCLUSIONS

Nuclear localization of beta-catenin is a characteristic feature of BCC; this suggests its tumorigenic role in this tumour. This gives us a further insight into the molecular pathogenesis of BCC.

[A case of disseminated intravascular coagulopathy (DIC) and multiple organ failure (MOF) after ingestion of hydrochloric acid]

Ingestion of caustic materials causes systemic damages and requires treatment in an intensive care unit. This report presents a case of disseminated intravascular coagulopathy (DIC) and multiple organ failure after ingestion of hydrochloric acid in an attempted suicide. The patient was admitted to the emergency ward within 1 hr after ingestion of 60 ml of 35% hydrochloric acid. Initial blood examination suggested hemolysis without anemia or thrombocytopenia. Arterial blood gas analysis exhibited evident metabolic acidosis with hypoxia. Two hours after ingestion, severe hemolysis, anemia, thrombocytopenia emerged with abnormal results from clotting and fiblinolysis tests, and a diagnosis of DIC was made. Subsequently, conjugate deviation and severe bleeding diathesis appeared. No evidence for gastrointestinal bleeding and brain hemorrhage was obtained in our abdominal echography and brain computed tomography, respectively. In spite of vigorous suppurative therapy including transfusion of blood, fresh frozen plasma, and catecholamines, the patient expired 29 hrs after ingestion. Autopsy was not carried out. Rapid progressive DIC as an acute complication of acid ingestion must be born in mind.

Spontaneous arterial baroreflex control of the heart rate during head-down tilt in heat-stressed humans

The purpose of this study was to elucidate the effect of raised body temperature per se during acute heat stress on the spontaneous arterial baroreflex control of heart rate (fc) in humans. To investigate whether unloading of cardiopulmonary baroreceptors during whole-body heating would alter the arterial baroreflex control of fc, we controlled loading of the cardiopulmonary baroreceptors by head-down tilt (HDT) at angles of 5 degrees, 10 degrees, 15 degrees, and 30 degrees during heat stress produced by hot-water-perfused suits. The sensitivity of the arterial baroreceptor-cardiac reflex was calculated from the spontaneous changes in beat-to-beat arterial pressure and fc. As an index of cardiopulmonary baroreceptor loading, the left atrial diameter (LAD) was measured by echocardiography. During whole-body heating, the LAD decreased with the rising body core temperature and increased with the HDT. The decreased LAD during heating almost recovered to the normothermic control level by 10 degrees HDT. In the supine position, cardiac baroreflex sensitivity remained unchanged during heating. Arterial pressure, fc and cardiac baroreflex sensitivity were not changed by HDT ranging from 5 degrees to 30 degrees during heating. These results suggest that cardiac baroreflex sensitivity remain unchanged during graded loading of the cardiopulmonary baroreceptors in heat-stressed humans. Also, we conclude that the sensitivity of the spontaneous arterial baroreflex controlling the fc is not influenced by raised body temperature per se during acute heat stress.

Increased antibody levels to desmogleins 1 and 3 after administration of carbamazepine

Desmoglein (Dsg) 1 and Dsg3 are recognized as the autoantigens in pemphigus foliaceus and pemphigus vulgaris. Pemphigus-like syndromes have been reported to occur in individuals after exposure to a variety of drugs, but pemphigus caused by carbamazepine is not common. We found that anti-Dsg1 and anti-Dsg3 antibody titres were increased in three individuals administered carbamazepine. Antibody titres against Dsgs 1 and 3 were measured by enzyme-linked immunosorbent assay (ELISA). Of 42 serum samples (25 patients administered carbamazepine, eight patients administered valproic acid and nine healthy volunteers) tested by ELISA, three patients administered carbamazepine showed positive reactivity against both Dsg1 and Dsg3. The patient with the highest titre against Dsg1 and Dsg3 (the index values of anti-Dsg1 and anti-Dsg3 were 79.3 and 86.4, respectively) was a 23-year-old woman (Case 1). The other two patients with positive reactivity were a 5-year-old boy (Case 2) and a 65-year-old man (Case 3). In addition, indirect immunofluorescence study showed intercellular antibodies to the cell surface of the whole epidermis with a titre of 1 : 64 in Case 1 and 1 : 2 in Cases 2 and 3. However, no skin or mucosal involvement was found in any of these cases. There was no difference in the serum concentrations of carbamazepine between the three positive cases and the 22 negative cases of carbamazepine administration. From these facts, the lack of skin diseases may be explained by relatively low values of anti-Dsg 1 and 3 antibodies in Cases 2 and 3. However, it cannot be excluded that undefined exogenous and/or endogenous factors are involved in an outbreak of pemphigus. Furthermore, these findings might be helpful for preventing susceptible individuals from exposure to the suspect drugs.

Water drinking causes a biphasic change in blood composition in humans

To investigate precisely the fluid shifts associated with water drinking in humans, we measured continuously blood density and plasma electrolyte concentrations using the mechanical oscillator technique and ion-selective electrodes, respectively, in healthy young volunteers before (10 min) and after (48 min) water drinking for a period of 2 min. Beat-by-beat blood pressure was also monitored throughout the experiment. Drinking 1 l tap water caused a transient increase in blood density immediately after the drinking episode (from 1051.1+/-0.5 g/l before drinking to 1051.8+/-0.5 g/l 4 min after the start of drinking, P<0.05), followed by a gradual reduction (1050.1+/-0.5 g/l at 31 min). This drinking-induced change paralleled those of haematocrit, plasma density and plasma volume. Plasma [Na+] and [Cl-] and osmolality decreased after drinking without transient increases and reached minima at about 30 min. A transient increase in mean arterial blood pressure was observed prior to the increase in blood density. These findings suggest that water drinking causes a biphasic change in plasma volume: initial haemoconcentration, probably due to sympathetic acceleration, followed by haemodilution due to the post-absorptive effect, and further suggest that the fluid shift associated with the initial haemoconcentration is isosmotic.

[Analysis of chimerism in patients with hematologic malignancies after allogeneic hematopoietic stem cell transplantation]

Serial monitoring of chimerism after allogeneic hematopoietic stem cell transplantation (HSCT) can be performed easily and rapidly using PCR-based assays analyzing informative tandem repeat genetic markers. Sequential analysis of individual chimerism status was performed in 34 patients who underwent myeloablative allo-HSCT using a commercial multiplex short tandem repeat (STR) kit. Mixed chimerism (MC) was found in 14 of the patients for more than one month. The incidence of MC seemed to be dependent on the type of disease or pretransplantation regimen. There was no significant difference in relapse rates between MC and complete donor chimerism (CC) in all patients. However, the relapse rate was significantly higher in MC than in CC among patients with acute leukemia. The severity of acute graft-versus-host disease (aGVHD) was significantly reduced in the patients with MC. Most of the MC patients with hematologic malignancies had transient mixed T-lymphoid chimerism, and CC was achieved within 6 months after HSCT in such cases. Patients with MC beyond 6 months after HSCT and patients with reappearance of autologous signals (MC after CC) may have an enhanced risk of relapse.

Pemphigus of the eyelids

We report the case of a 56-year-old woman who presented with a 2-month history of widespread oral erosion and a 3-day history of small papules on the lower eyelids. No other skin involvement was found. Histopathological examination revealed suprabasal cleft and acantholysis in the lower epidermis of the papule on the lower eyelid and in the lower mucous membrane of the oral mucosa. Intercellular deposits of IgG and C3 were seen in the whole epidermis of the specimen from the papule on the right lower eyelid by direct immunofluorescence study. These deposits were also observed in the biopsy specimen from erosion on the left buccal membrane. Indirect immunofluorescence study using normal human skin as a substrate showed intercellular antibodies directed to the cell surface of the whole epidermis with a titer of 1:40. The titers of antibodies to desmoglein 3 and 1 were 118 and 25.9, respectively, by enzyme-linked immunosorbent assay. The patient was treated with an oral administration of prednisolone (0.75 mg/kg/day) for 9 days, which improved the skin eruptions and oral erosion. The dose of prednisolone was gradually tapered and it took 10 weeks to cease this treatment. These findings suggest that this patient is an unusual case of pemphigus vulgaris (mucosal dominant type) diagnosed from the clinical and histopathological findings, with positive antibodies to desmoglein 3 and 1.

Thermal stress modulates arterial pressure variability and arterial baroreflex response of heart rate during head-up tilt in humans

To examine the effects of thermal stress on the blood pressure variability and the arterial baroreceptor-cardiac reflex during orthostatic stress, 11 male volunteers underwent whole body thermal stress using a cool or hot water-perfused suit during 5 min of 70 degrees head-up tilt (HUT). The spontaneous variability in arterial pressure was quantified by power spectrum analysis. The sensitivity of the arterial baroreceptor-cardiac reflex was calculated from the spontaneous changes in beat-to-beat arterial pressure and heart rate (fc). During supine rest the variability of arterial pressure decreased during cooling, while it remained unchanged during heating. The variability increased with HUT; it was greater (P < 0.05) with heating than with cooling. In the supine condition, the arterial baroreflex sensitivity of fc increased during cooling, while it did not change during heating. The sensitivities decreased (P < 0.05) with HUT during both thermal stresses; the decreased rate of sensitivity from the pre-tilt value was greater during heating [mean 63 (SEM 4)%] and smaller during cooling [mean 11 (SEM 24)%] than during normothermia [mean 47 (SEM 4)%] (both, P < 0.05). There were significant negative correlations between the sensitivities and the amplitude of the arterial pressure variability during normothermia and heating (P < 0.0001). The results suggest that the spontaneous baroreflex response of fc is a modulatory factor for the changes of arterial pressure variability brought about by thermal stress during orthostatic stress.

Contribution of TNF-alpha and IL-10 gene polymorphisms to graft-versus-host disease following allo-hematopoietic stem cell transplantation

Some cytokines are believed to play a role in the development of acute and chronic GVHD after allo-hematopoietic stem cell transplantation. It has been reported that TNF-alpha and IL-10 gene polymorphisms are associated with the production of those cytokines and the development of graft failure after organ transplantation and systemic lupus erythematosus. We examined whether TNF-alpha and IL-10 gene polymorphisms affect the severity of acute GVHD (aGVHD) and chronic GVHD (cGVHD). Sixty-two and 54 patients were available for the analysis of aGVHD and cGVHD, respectively. We analyzed the gene polymorphisms derived from pre- and post-transplant blood cells. Donor-derived TNF2 allele (A) was more frequently detected in patients with aGVHD III/IV than those aGVHD 0-II (2/6 vs 2/56) (P = 0.04). The donors of the patients with cGVHD more frequently possessed a greater number of alleles (allele 13 or more which contain 26 or more CA repeats) in IL-10.G than those without (13/26 vs 5/28) (P = 0.02), and the patients with cGVHD had more CA repeats in donor-derived IL-10.G than those without (mean = 25.2 vs 23.4) (P = 0.01). Donor-derived TNF-308 and IL-10.G alleles may contribute to severe aGVHD and cGVHD, respectively, and will help us distinguish those patients at high risk for GVHD.

Continuous monitoring of change in hemodilution during water immersion in humans: effect of water temperature

BACKGROUND

The present study was designed to examine whether water temperature during head-out immersion (HOI) modifies hemodilution dynamics.

METHODS

We made continuous measurements of blood density (rho(b)) during HOI at 3 different water temperatures; the lower critical (32 degrees C), neutral (34.5 degrees C), and upper critical (36 degrees C) temperatures in 6 healthy male volunteers. Blood was withdrawn continuously from the antecubital vein for measurement of rho(b) during 60 min of water immersion with a 10-min control period before the immersion. The density was measured with the mechanical oscillator technique. Hematocrit (Hct), plasma density (rho(p)), and osmolality were measured at 5-min intervals. Erythrocyte density (rho(e)) was calculated from rho(b), rho(p) and Hct. Cardiac output and BP were measured to calculate total peripheral resistance.

RESULTS

Hct, rho(b), and rho(p) decreased rapidly in the first 20-25 min of immersion and were maintained at a reduced level during immersion. Plasma volume calculated from rho(p) and Hct increased with the rho(b) reduction. These immersion-induced changes were independent of these water temperatures. Plasma osmolality and rho(e) remained constant throughout the experimental period in the three temperature conditions, indicating that the increase in plasma volume and hence hemodilution was induced by an isotonic fluid shift from extravascular space. The total peripheral resistance increased inversely in proportion to the water temperature during HOI.

CONCLUSION

In the present condition, water temperature did not modify the net transcapillary fluid transfer during HOI in the presence of the temperature dependent increase in vascular tone.

Cardiac and peripheral vascular responses to head-up tilt during whole body thermal stress

During acute orthostatic stress, neurally mediated control of cardiac output (CO) and total peripheral vascular resistance (TPR) play an important role in the maintenance of systemic blood pressure. To examine the influence of thermal stress on the CO and TPR responses to orthostatic stress, 10 healthy male volunteers were exposed to normothermic control conditions followed by whole-body thermal stress produced by a cold or hot water-perfused suit during 5 min-70 degrees head-up tilt (HUT). HUT increased mean arterial pressure (MAP) by 3% of the pre-tilt value during normothermic control and cooling, whereas it decreased MAP by 4% of the pre-tilt value during heating. HUT decreased CO by 16-17% of the pre-tilt value under each thermal condition. The increase of TPR during HUT was exaggerated during cooling and inhibited during heating compared to normothermic control. Tilt-induced decrease of skin blood flow was greater during heating than cooling. These results suggest that the smaller increase of TPR rather than the CO change is responsible for the decreased MAP during acute orthostatic stress in hyperthermic humans. The contribution of skin vascular constriction to TPR changes during HUT is increased during heating and decreased during cooling.

Polymorphisms of tumor necrosis factor-alpha and interleukin-10 genes in Japanese patients with idiopathic dilated cardiomyopathy

Various cytokines play important roles in the pathogenesis of congestive heart failure. TNF-alpha is one of the pro-inflammatory cytokines, and IL-10 has anti-inflammatory actions. The -308 (G / A) polymorphism of the TNF-alpha gene (TNFA1 and A2) and the single base -1082 (G / A) polymorphism of the IL-10 gene (IL-10 1*G and 1*A) have been identified as causing alterations to the in vivo production of TNF-alpha and IL-10, respectively. We examined TNF-alpha and IL-10 gene polymorphisms using a polymerase chain reaction-restriction fragment length polymorphism technique in 48 Japanese patients with idiopathic dilated cardiomyopathy. The frequency of these polymorphisms was compared with 50 healthy Japanese. The clinical courses, such as disease onset, left ventricular function, progression during the follow up period and hospitalization from congestive heart failure, were also analyzed. Serum TNF-alpha levels were measured using an enzyme-linked immunosorbent assay (ELISA) technique in the patients with idiopathic dilated cardiomyopathy to reveal the correlation with genotypes. Patients with ischemic cardiomyopathy or other secondary cardiomyopathies were excluded from this study. The allele frequency of TNFA2 in idiopathic dilated cardiomyopathy was significantly higher than that of the healthy group (13.5% and 3.0%, respectively, p = 0.0084). There was no difference in the allele frequency of the IL-10 gene between the two groups. Polymorphism of the TNFA2 gene was not associated with the clinical course. Serum TNF-alpha levels were elevated in the patient group compared with the healthy group. There were no differences in serum TNF-alpha levels between the patients with TNFA1 and those with TNFA2. In conclusion, the TNFA2 allele may be linked to the pathogenesis of idiopathic dilated cardiomyopathy in Japanese patients.

Modulation of arterial baroreflex control of heart rate by skin cooling and heating in humans

The purpose of this study was to examine the effects of skin cooling and heating on the heart rate (HR) control by the arterial baroreflex in humans. The subjects were 15 healthy men who underwent whole body thermal stress (esophageal temperatures, approximately 36.8 and approximately 37.0 degrees C; mean skin temperatures, approximately 26.4 and approximately 37.7 degrees C, in skin cooling and heating, respectively) produced by a cool or hot water-perfused suit during supine rest. The overall arterial baroreflex sensitivity in the HR control was calculated from spontaneous changes in beat-to-beat arterial pressure and HR during normothermic control and thermal stress periods. The carotid baroreflex sensitivity was evaluated from the maximum slope of the HR response to changes in carotid distending pressure, calculated as mean arterial pressure minus neck pressure. The overall arterial baroreflex sensitivity at existing arterial pressure increased during cooling (-1.32 +/- 0.25 vs. -2.13 +/- 0.20 beats. min(-1). mmHg(-1) in the control and cooling periods, respectively, P < 0.05), whereas it did not change significantly during heating (-1.39 +/- 0. 23 vs. -1.40 +/- 0.15 beats. min(-1). mmHg(-1) in the control and heating periods, respectively). Neither the cool nor heat loadings altered the carotid baroreflex sensitivity in the HR control. These results suggest that the sensitivity of HR control by the extracarotid (presumably aortic) baroreflex was augmented by whole body skin cooling, whereas the sensitivities of HR control by arterial baroreflex remain unchanged during mild whole body heating in humans.