Anoxia-induced hippocampal LTP is regeneratively produced by glutamate and nitric oxide from the neuro-glial-endothelial axis

Transient anoxia causes amnesia and neuronal death. This is attributed to enhanced glutamate release and modeled as anoxia-induced long-term potentiation (aLTP). aLTP is mediated by glutamate receptors and nitric oxide (·NO) and occludes stimulation-induced LTP. We identified a signaling cascade downstream of ·NO leading to glutamate release and a glutamate-·NO loop regeneratively boosting aLTP. aLTP in entothelial ·NO synthase (eNOS)-knockout mice and blocking neuronal NOS (nNOS) activity suggested that both nNOS and eNOS contribute to aLTP. Immunostaining result showed that eNOS is predominantly expressed in vascular endothelia. Transient anoxia induced a long-lasting Ca2+ elevation in astrocytes that mirrored aLTP. Blocking astrocyte metabolism or depletion of the NMDA receptor ligand D-serine abolished eNOS-dependent aLTP, suggesting that astrocytic Ca2+ elevation stimulates D-serine release from endfeet to endothelia, thereby releasing ·NO synthesized by eNOS. Thus, the neuro-glial-endothelial axis is involved in long-term enhancement of glutamate release after transient anoxia.

Prognostic Impact of a Negative Central Pelvic Biopsy after Definitive Chemoradiotherapy (CRT) for Locally Advanced Cervical Cancer (LACC)

PURPOSE/OBJECTIVE(S)

Central pelvic biopsies are occasionally performed during post-treatment surveillance of locally advanced cervical cancer (LACC) after a change in symptoms, abnormal pelvic exam, pap smear or imaging. Although it is established that a positive result is considered disease recurrence, it is unclear the prognostic impact of a negative biopsy. Here, we investigated the characteristics and the clinical course of patients with negative biopsy, focusing on central pelvic recurrence.

MATERIALS/METHODS

Our institutional database of female patients with diagnosis of cervical cancer treated with definitive CRT was retrospectively reviewed (2013-2022). The central pelvic region was subdivided in: I) cervix, II) endocervix/endometrium, III) vagina, IV) vulva, V) bladder and VI) rectum. Each subsite sampled was considered a distinct biopsy event, but multiple samples from one subsite at the same procedure were considered one biopsy event. We calculated the rate of initial negative and positive biopsies. The central pelvic control (local recurrence rate [LCRR]) for patients with negative biopsy was estimated with Kaplan Meier method.

RESULTS

Two hundred and twenty-five consecutive patients were included (initial FIGO 2018 staging: 30% I/II and 70% III-IVA). Of these, 66 (29.3%) underwent 112 central pelvic biopsies (average 1.7 per patient) during a median follow up time of 27.1 months [range: 0.2-94.0], with median time from treatment to first biopsy of 7.0 months [range: 1.0-41.7]. Biopsies were triggered by: symptoms/physical exam in 83 (73.4%), imaging abnormalities in 21 (18.6%), and abnormal pap smear in 9 (8%). The most common structures biopsied were: cervix (53.6%, n = 60), vagina (17.9%, n = 20), endocervix/endometrium (11.6%, n = 13), rectum/sigmoid (11.6%, n = 13), bladder (4.5%, n = 5) and vulva (0.9%, n = 1). Overall, 13.6% cases (9/66) had an initial positive biopsy, while 86.4% (57/66) had an initial negative biopsy. Of these patients with negative biopsies, 84.2% (48/57) remained without evidence of local recurrence and 15.8% (9/57) were subsequently diagnosed with local disease recurrence (1y post-biopsy LCRR 15.0% [95% CI 4.8-24.0]).

CONCLUSION

Although most (>85%) post-treatment central pelvic biopsies are negative, these patients are still at considerable risk of early local recurrence thereafter (post-biopsy 1y-LCRR 15%). Strategies to intensify surveillance may be beneficial in the first year after a negative biopsy.

Management of inferior vena cava aneurysm

AIM

Inferior vena cava (IVC) aneurysm is an infrequent but potentially lethal abnormality. We have seen one such case in our group practice. We have added this case to a review of 53 previously reported cases in order to develop a management algorithm for this entity.

METHODS

We conducted a MedLine search of all English-language articles from the first reported case in 1950 through August 2013. Patient demographics, clinical data, management and outcomes were extracted. IVC aneurysms were categorized in 4 types as per Gradman and Steinberg classification.

RESULTS

The mean patient age was 27.1 years (range 5-89) and 57.4% were male. A total of 11 (20.3%) had associated vascular anomalies and iliocaval thrombosis was found in 10 (18.5%). There were 23 type I aneurysms, 8 type IIs, 21 type IIIs and 2 type IVs. All but 1 type I was successfully managed conservatively without complications. For type IIs, only 3 patients were managed conservatively with 1 death related to stroke from paradoxical embolus. For type IIIs, resection was the most common management option (14 patients). One patient was treated endovascularly with aneurysm embolization. A total of 6 asymptomatic patients were treated conservatively with 1 death due to thromboembolism. For type IVs, all cases underwent expectant management with 1 death due to aneurysm rupture.

CONCLUSION

IVC aneurysms are rare with only 54 cases reported in the literature. Associated vascular anomalies and iliocaval thrombosis should be expected in approximately 20% of cases. Type I aneurysms can be managed expectantly with close surveillance unless symptomatic. For type II-IV, surgical consideration should be given based on high rates of thromboembolic complications and non-negligible risk of rupture.

Quality of mesorectum after laparoscopic resection for rectal cancer - results of an audited teaching programme in Spain

OBJECTIVE

The aim of this prospective observational study was to compare the quality of total mesorectal excision between laparoscopic and open surgery for rectal cancer.

METHOD

In April 2006, the Spanish Association of Surgeons started an audited teaching programme. The project was similar to the Norwegian one and several training courses were arranged. Patients were classified into two groups: laparoscopic rectal resection (LR) and open rectal resection (OR). The quality of the mesorectum was scored: complete, nearly complete or incomplete. The circumferential margin (CRM) was considered positive, if tumour was located 1 mm or less from the surface of the specimen.

RESULTS

Between 2006 and 2008, 604 patients underwent rectal resection with total mesorectal excision for rectal cancer: 209 patients were included in the LR group and 395 patients in the OR group. There were no differences in terms of number of lymph nodes affected, distance of the tumour from CRM. The mesorectum was complete in 464 (76.8%), nearly complete in 91 (15.1%) and incomplete in 49 patients (8.1%). CRM was negative in 534 patients (88.4%). No differences were observed between the two groups. The overall postoperative morbidity rate was 38.8% in LR group and 44.6% in OR group (P = 0.170). Overall postoperative mortality rate was 2.5%. One patient died (0.5%) in the LR group and 14 patients died (3.5%) in the OR group (P = 0.021).

CONCLUSION

Laparoscopic resection for rectal cancer is feasible with the quality of mesorectal excision and postoperative outcomes similar to those of open surgery.